REFERENCE VALUES FOR FISH EXPOSURE TO PAH CONTAMINANTS: COMPARISON OF OHIO AND THE MID-ATLANTIC REGION

EPA Science Inventory

Reference values for exposure of wildlife to contaminants are needed to cost effectively determine if a site is contaminated and to rank sites that are above background levels. Epidemiological techniques originally developed for clinical chemistry and for determining exposures t...

Thyroid nodularity and chromosome aberrations among women in areas of high background radiation in China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Z.Y.; Boice, J.D. Jr.; Wei, L.X.

1990-03-21

Thyroid nodularity following continuous low-dose radiation exposure in China was determined in 1,001 women aged 50-65 years who resided in areas of high background radiation (330 mR/yr) their entire lives, and in 1,005 comparison subjects exposed to normal levels of radiation (114 mR/yr). Cumulative doses to the thyroid were estimated to be of the order of 14 cGy and 5 cGy, respectively. Personal interviews and physical examinations were conducted, and measurements were made of serum thyroid hormone levels, urinary iodine concentrations, and chromosome aberrations in circulating lymphocytes. For all nodular disease, the prevalences in the high background and control areasmore » were 9.5% and 9.3%, respectively. For single nodules, the prevalences were 7.4% in the high background area and 6.6% in the control area (prevalence ratio = 1.13; 95% confidence interval = 0.82-1.55). There were no differences found in serum levels of thyroid hormones. Women in the high background region, however, had significantly lower concentrations of urinary iodine and significantly higher frequencies of stable and unstable chromosome aberrations. Increased intake of allium vegetables such as garlic and onions was associated with a decreased risk of nodular disease, which seems consistent with experimental studies suggesting that allium compounds can inhibit tumor growth and proliferation. The prevalence of mild diffuse goiter was higher in the high background radiation region, perhaps related to a low dietary intake of iodine. These data suggest that continuous exposure to low-level radiation throughout life is unlikely to appreciably increase the risk of thyroid cancer. However, such exposure may cause chromosomal damage.« less

County‐level cumulative environmental quality associated with cancer incidence

EPA Science Inventory

Background: Cancer risk is affected by a combination of behavioral, genetic, and environmental factors. Individual environmental exposures have been associated with cancer development; however, a variety of environmental exposures may occur simultaneously. The Environmental Quali...

Benzene metabolite levels in blood and bone marrow of B6C3F{sub 1} mice after low-level exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bechtold, W.E.; Strunk, M.R.; Thornton-Manning, J.R.

1995-12-01

Studies at the Inhalation Toxicology Research Institute (ITRI) have explored the species-specific uptake and metabolism of benzene. Results have shown that metabolism is dependent on both dose and route of administration. Of particular interest were shifts in the major metabolic pathways as a function of exposure concentration. In these studies, B6C3F{sub 1} mice were exposed to increasing levels of benzene by either gavage or inhalation. As benzene internal dose increased, the relative amounts of muconic acid and hydroquinone decreased. In contrast, the relative amount of catechol increased with increasing exposure. These results show that the relative levels of toxic metabolitesmore » are a function of exposure level. Based on these results and assuming a linear relationship between exposure concentration and levels of bone marrow metabolites, it would be difficult to detect an elevation of any phenolic metabolites above background after occupational exposures to the OSHA Permissible Exposure Limit of 1 ppm benzene.« less

Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) in the Oil and Gas Industry: A Review.

PubMed

Doyi, Israel; Essumang, David Kofi; Dampare, Samuel; Glover, Eric Tetteh

Radiation is part of the natural environment: it is estimated that approximately 80 % of all human exposure comes from naturally occurring or background radiation. Certain extractive industries such as mining and oil logging have the potential to increase the risk of radiation exposure to the environment and humans by concentrating the quantities of naturally occurring radiation beyond normal background levels (Azeri-Chirag-Gunashli 2004).

S-phenyl-N-acetylcysteine in urine of rats and workers after exposure to benzene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jongeneelen, F.J.; Dirven, H.A.; Leijdekkers, C.M.

1987-05-01

An HPLC method for the determination of S-phenyl-N-acetylcysteine in urine is described. The sensitivity is 6 mumol/L (CV = 9%) urine. Exposure of rats to six different concentrations of benzene, ranging from 0-30 ppm, was highly associated with urinary excretion of S-phenyl-N-acetylcysteine (r = 0.86) and with total phenol (r = 0.81). A background level of phenol was found in urine of both non-exposed rats and of non-exposed referents. However, no background excretion of S-phenyl-N-acetylcysteine was found, either in rats or in humans. In urine of exposed rats, the level of S-phenyl-N-acetylcysteine was approximately five times lower than the phenolmore » level. Workers occupationally exposed to benzene, showing high levels of urinary phenol, revealed low concentrations of urinary S-phenyl-N-acetylcysteine. The biological monitoring of industrial exposure to benzene by determination of S-phenyl-N-acetylcysteine in urine is not better than the determination of phenol in urine.« less

Public exposure due to external gamma background radiation in boundary areas of Iran.

PubMed

Pooya, S M Hosseini; Dashtipour, M R; Enferadi, A; Orouji, T

2015-09-01

A monitoring program in boundary areas of a country is an appropriate way to indicate the level of public exposure. In this research, gamma background radiation was measured using TL dosimeters at 12 boundary areas as well as in the capital city of Iran during the period 2010 to 2011. The measurements were carried out in semi-annual time intervals from January to June and July to December in each year. The maximum average dose equivalent value measured was approximately 70 μSv/month for Tehran city. Also, the average dose values obtained were less than 40 μSv/month for all the cities located at the sea level except that of high level natural radiation area of Ramsar, and more than 55 μSv/month for the higher elevation cities. The public exposure due to ambient gamma dose equivalent in Iran is within the levels reported by UNSCEAR. Copyright © 2015 Elsevier Ltd. All rights reserved.

COMPARISON OF MID-WESTERN AND MID-ATLANTIC REGIONS EXPOSURE CRITERIA FOR PETROLEUM AND COMBUSTION BY-PRODUCTS

EPA Science Inventory

Regional background levels of exposure to fish from petroleum and combustion by-products were determined for the state of Ohio (mid-Western) and the mid-Atlantic region. Exposures were measured using bile metabolites that fluoresce at 290/335 nm for naphthalene (NAPH)-type compou...

75 FR 75389 - Metrafenone; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-03

... and wine grapes at 4.5 parts per million (ppm), juice grapes at 0.45 ppm, and raisin grapes at 17 ppm... that the proposed tolerances for wine and juice grapes are not needed. The reason for this change is... residential exposure plus chronic exposure to food and water (considered to be a background exposure level...

Neuropsychological Motor Outcomes in Adults from Airborne Manganese Exposure

EPA Science Inventory

Background: The literature on manganese (Mn) is dominated by occupational exposures of adults exposed often to high levels without protection. Neuropsychological adverse health effects are similar to Parkinson’s Disease with psychomotor slowing, tremor, cognitive and mood ...

Ultrafine particle levels at an international port of entry between the US and Mexico: exposure implications for users, workers, and neighbors.

PubMed

Olvera, Hector A; Lopez, Mario; Guerrero, Veronica; Garcia, Humberto; Li, Wen-Whai

2013-01-01

Exposure to diesel-emitted particles has been linked to increased cancer risk and cardiopulmonary diseases. Because of their size (<100 nm), exposure to ultrafine particles (UFPs) emitted from heavy-duty diesel vehicles (HDDV) might result in greater health risks than those associated with larger particles. Seasonal UFP levels at the International Bridge of the Americas, which connects the US and Mexico and has high HDDV traffic demands, were characterized. Hourly average UFP concentrations ranged between 1.7 × 10(3)/cc and 2.9 × 10(5)/cc with a mean of 3.5 × 10(4)/cc. Wind speeds <2 m s(-1) and temperatures <15 °C were associated with particle number concentrations above normal conditions. The presence of HDDV had the strongest impact on local UFP levels. Varying particle size distributions were associated with south- and northbound HDDV traffic. Peak exposure occurred on weekday afternoons. Although in winter, high exposure episodes were also observed in the morning. Particle number concentrations were estimated to reach background levels at 400 m away from traffic. The populations exposed to UFP above background levels include law enforcement officers, street vendors, private commuters, and commercial vehicle drivers as well as neighbors on both sides of the border, including a church and several schools.

DEVELOPMENT OF ARSENIC SPECIATION METHODOLOGY FOR DETERMINING BACKGROUND EXPOSURE LEVELS OF INORGANIC ARSENIC IN DIETARY SAMPLES AND APPLICATION TO IN VITRO BIOACCESSIBILITY STUDIES

EPA Science Inventory

Ingestion of arsenic is the primary route of exposure for most people, with dietary intake and drinking water as the primary sources of that exposure. Traditionally, measurements of arsenic dietary intake are based on food consumption data coupled with total arsenic data from a ...

Inconstant sun: how solar evolution has affected cosmic and ultraviolet radiation exposure over the history of life on Earth.

PubMed

Karam, P Andrew

2003-03-01

Four billion years ago, sea-level UV exposure was more than 400 times as intense as today, the dose from solar cosmic rays was five times present levels, and galactic cosmic rays accounted for only about 10% their current contribution to sea-level radiation doses. Exposure to cosmic radiation accounts for about 10% of natural background radiation exposure today and includes dose from galactic cosmic rays and solar charged particles. There is little exposure to ionizing wavelengths of UV due to absorption by ozone. The sun has evolved significantly over its life; in the past there were higher levels of particulate radiation and lower UV emissions from the sun, and a stronger solar wind reduced radiation dose in the inner solar system from galactic cosmic rays. Finally, since the early atmosphere contained little to no oxygen, surface levels of UV radiation were far higher in the past.

Assessment of impact of urbanisation on background radiation exposure and human health risk estimation in Kuala Lumpur, Malaysia.

PubMed

Sanusi, M S M; Ramli, A T; Hassan, W M S W; Lee, M H; Izham, A; Said, M N; Wagiran, H; Heryanshah, A

2017-07-01

Kuala Lumpur has been undergoing rapid urbanisation process, mainly in infrastructure development. The opening of new township and residential in former tin mining areas, particularly in the heavy mineral- or tin-bearing alluvial soil in Kuala Lumpur, is a contentious subject in land-use regulation. Construction practices, i.e. reclamation and dredging in these areas are potential to enhance the radioactivity levels of soil and subsequently, increase the existing background gamma radiation levels. This situation is worsened with the utilisation of tin tailings as construction materials apart from unavoidable soil pollutions due to naturally occurring radioactive materials in construction materials, e.g. granitic aggregate, cement and red clay brick. This study was conducted to assess the urbanisation impacts on background gamma radiation in Kuala Lumpur. The study found that the mean value of measured dose rate was 251±6nGyh -1 (156-392nGyh -1 ) and 4 times higher than the world average value. High radioactivity levels of 238 U (95±12Bqkg -1 ), 232 Th (191±23Bqkg -1 ,) and 40 K (727±130Bqkg -1 ) in soil were identified as the major source of high radiation exposure. Based on statistical ANOVA, t-test, and analyses of cumulative probability distribution, this study has statistically verified the dose enhancements in the background radiation. The effective dose was estimated to be 0.31±0.01mSvy -1 per man. The recommended ICRP reference level (1-20mSvy -1 ) is applicable to the involved existing exposure situation in this study. The estimated effective dose in this study is lower than the ICRP reference level and too low to cause deterministic radiation effects. Nevertheless based on estimations of lifetime radiation exposure risks, this study found that there was small probability for individual in Kuala Lumpur being diagnosed with cancer and dying of cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

Polychlorinated biphenyl sources, environmental levels, and exposures in school buildings

EPA Science Inventory

Background: Building materials and components containing polychlorinated biphenyls (PCBs) were used in some U.S. school buildings until the late 1970s and may be present today. There is limited information on source factors and occupant exposures. Methods: Analysis of PCBs in mat...

Speaking up: Killer whales (Orcinus orca) increase their call amplitude in response to vessel noise.

PubMed

Holt, Marla M; Noren, Dawn P; Veirs, Val; Emmons, Candice K; Veirs, Scott

2009-01-01

This study investigated the effects of anthropogenic sound exposure on the vocal behavior of free-ranging killer whales. Endangered Southern Resident killer whales inhabit areas including the urban coastal waters of Puget Sound near Seattle, WA, where anthropogenic sounds are ubiquitous, particularly those from motorized vessels. A calibrated recording system was used to measure killer whale call source levels and background noise levels (1-40 kHz). Results show that whales increased their call amplitude by 1 dB for every 1 dB increase in background noise levels. Furthermore, nearby vessel counts were positively correlated with these observed background noise levels.

Health risk assessment of air emissions from a municipal solid waste incineration plant--a case study.

PubMed

Cangialosi, Federico; Intini, Gianluca; Liberti, Lorenzo; Notarnicola, Michele; Stellacci, Paolo

2008-01-01

A health risk assessment of long-term emissions of carcinogenic and non-carcinogenic air pollutants has been carried out for the municipal solid waste incinerator (MSWI) of the city of Taranto, Italy. Ground level air concentrations and soil deposition of carcinogenic (Polychlorinated Dibenzo-p-Dioxins/Furans and Cd) and non-carcinogenic (Pb and Hg) pollutants have been estimated using a well documented atmospheric dispersion model. Health risk values for air inhalation, dermal contact, soil and food ingestion have been calculated based on a combination of these concentrations and a matrix of environmental exposure factors. Exposure of the surrounding population has been addressed for different release scenarios based on four pollutants, four exposure pathways and two receptor groups (children and adults). Spatial risk distribution and cancer excess cases projected from plant emissions have been compared with background mortality records. Estimated results based on the MSWI emissions show: (1) individual risks well below maximum acceptable levels, (2) very small incremental cancer risk compared with background level.

An Evaluation of UV-Monitoring Enhanced Skin Cancer Prevention among Farm Youth in Rural Virginia

ERIC Educational Resources Information Center

Chen, Yi-Chun; Ohanehi, Donatus C.; Redican, Kerry J.

2015-01-01

Background: Health districts in southwest Virginia have one of the highest ultraviolet (UV) radiation exposure and sunburn rate. Due to higher levels of UV exposure, rural farm youth are at higher risk for skin cancer than non-farm youth. Few studies have been published that explore best practices for decreasing UV exposure among this population.…

Perfluoroalkyl substances during pregnancy and validated preeclampsia among nulliparous women in the Norwegian Mother and Child Cohort Study.

PubMed

Starling, Anne P; Engel, Stephanie M; Richardson, David B; Baird, Donna D; Haug, Line S; Stuebe, Alison M; Klungsøyr, Kari; Harmon, Quaker; Becher, Georg; Thomsen, Cathrine; Sabaredzovic, Azemira; Eggesbø, Merete; Hoppin, Jane A; Travlos, Gregory S; Wilson, Ralph E; Trogstad, Lill I; Magnus, Per; Longnecker, Matthew P

2014-04-01

Perfluoroalkyl substances (PFAS) are persistent and ubiquitous environmental contaminants, and human exposure to these substances may be related to preeclampsia, a common pregnancy complication. Previous studies have found serum concentrations of PFAS to be positively associated with pregnancy-induced hypertension and preeclampsia in a population with high levels of exposure to perfluorooctanoate. Whether this association exists among pregnant women with background levels of PFAS exposure is unknown. Using data from the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health, we carried out a study of nulliparous pregnant women enrolled in 2003-2007 (466 cases, 510 noncases) to estimate associations between PFAS concentrations and an independently validated diagnosis of preeclampsia. We measured levels of 9 PFAS in maternal plasma extracted midpregnancy; statistical analyses were restricted to 7 PFAS that were quantifiable in more than 50% of samples. In proportional hazards models adjusted for maternal age, prepregnancy body mass index (weight (kg)/height (m)(2)), educational level, and smoking status, we observed no strongly positive associations between PFAS levels and preeclampsia. We found an inverse association between preeclampsia and the highest quartile of perfluoroundecanoic acid concentration relative to the lowest quartile (hazard ratio = 0.55, 95% confidence interval: 0.38, 0.81). Overall, our findings do not support an increased risk of preeclampsia among nulliparous Norwegian women with background levels of PFAS exposure.

Health inequalities among workers with a foreign background in Sweden: do working conditions matter?

PubMed

Dunlavy, Andrea C; Rostila, Mikael

2013-07-10

Employment and working conditions are key social determinants of health, yet current information is lacking regarding relationships between foreign background status, working conditions and health among workers in Sweden. This study utilized cross-sectional data from the 2010 Swedish Level of Living Survey (LNU) and the Level of Living Survey for Foreign Born Persons and their Children (LNU-UFB) to assess whether or not health inequalities exist between native Swedish and foreign background workers and if exposure to adverse psychosocial and physical working conditions contributes to the risk for poor health among foreign background workers. A sub-sample of 4,021 employed individuals aged 18-65 was analyzed using logistic regression. Eastern European, Latin American and Other Non-Western workers had an increased risk of both poor self-rated health and mental distress compared to native Swedish workers. Exposure to adverse working conditions only minimally influenced the risk of poor health. Further research should examine workers who are less integrated or who have less secure labor market attachments and also investigate how additional working conditions may influence associations between health and foreign background status.

Workplace air measurements and likelihood of exposure to manufactured nano-objects, agglomerates, and aggregates

NASA Astrophysics Data System (ADS)

Brouwer, Derk H.; van Duuren-Stuurman, Birgit; Berges, Markus; Bard, Delphine; Jankowska, Elzbieta; Moehlmann, Carsten; Pelzer, Johannes; Mark, Dave

2013-11-01

Manufactured nano-objects, agglomerates, and aggregates (NOAA) may have adverse effect on human health, but little is known about occupational risks since actual estimates of exposure are lacking. In a large-scale workplace air-monitoring campaign, 19 enterprises were visited and 120 potential exposure scenarios were measured. A multi-metric exposure assessment approach was followed and a decision logic was developed to afford analysis of all results in concert. The overall evaluation was classified by categories of likelihood of exposure. At task level about 53 % showed increased particle number or surface area concentration compared to "background" level, whereas 72 % of the TEM samples revealed an indication that NOAA were present in the workplace. For 54 out of the 120 task-based exposure scenarios, an overall evaluation could be made based on all parameters of the decision logic. For only 1 exposure scenario (approximately 2 %), the highest level of potential likelihood was assigned, whereas in total in 56 % of the exposure scenarios the overall evaluation revealed the lowest level of likelihood. However, for the remaining 42 % exposure to NOAA could not be excluded.

A prospective study of marine phytoplankton and reported illness among recreational beachgoers in Puerto Rico, 2009

EPA Science Inventory

BACKGROUND: Blooms of marine phytoplankton may adversely affect human health. The potential public health impact of low-level exposures is not well established, and few prospective cohort studies of recreational exposures to marine phytoplankton have been conducted.OBJECTIVE: We ...

Development of Advisory Levels for Polychlorinated Biphenyls (PCBS) Cleanup

EPA Science Inventory

The document presents background information used in developing advisory levels of PCBs in soil estimated to be permissible in protecting public health. The results of exposure assessment and health effects studies are combined to arrive at the permissible levels of PCBs. Health ...

Helping Children Cope with the Consequences of Violence.

ERIC Educational Resources Information Center

Wallach, Lorraine B.

The first part of this paper on the developmental consequences of children's exposure to chronic violence provides background information on the problem of violence. Developmental consequences of exposure to domestic and community violence for children at various developmental levels are briefly outlined. Consequences for children include: (1)…

Modifying effect of the County Level Health Indices on Cardiopulmonary Effects Associated with Wildfire Exposure

EPA Science Inventory

Background and Aims: Socioeconomic status (SES) is a known risk factor for cardiopulmonary health and some studies suggest SES may be an effect modifier for health effects associated with exposure to air pollution. We investigated the synergistic impact of health disparities on ...

CHANGES IN PROTEOMIC PROFILES OF CEREBELLUM AND HIPPOCAMPUS FOLLOWING EXPOSURE TO A DEVELOPMENTAL NEUROTOXICANT.

EPA Science Inventory

The vast literature on the group of chemicals known as polychlorinated biphenyls (PCBs) makes it a unique model to understand major issues related to environmental mixtures of persistent chemicals. At background levels of exposure, PCBs have been shown to adversely affect human h...

75 FR 19272 - Thifensulfuron methyl; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-14

... background exposure level). A short and intermediate-term adverse effect was identified; however... of small renal papillae (only at the highest dose level). Thifensulfuron methyl is classified as... only at the mid-level dose of 177 mg/kg. The lack of response at the high-level dose, the occurrence in...

49 CFR Appendix E to Part 227 - Use of Insert Earphones for Audiometric Testing

Code of Federal Regulations, 2010 CFR

2010-10-01

... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OCCUPATIONAL NOISE EXPOSURE Pt. 227, App. E Appendix.... B. Technicians who conduct audiometric tests must be trained to insert the earphones correctly into... audiometer. IV. Background Noise Levels Testing shall be conducted in a room where the background ambient...

RELATIONSHIPS BETWEEN LEVELS OF VOLATILE ORGANIC COMPOUNDS IN AIR AND BLOOD FROM THE GENERAL POPULATION

EPA Science Inventory

Background: The relationships between levels of volatile organic compounds (VOCs) in blood and air have not been well characterized in the general population where exposure concentrations are generally at ppb levels. Objectives: This study investigates relationships between ...

Initiation-promotion model of tumor prevalence in mice from space radiation exposures

NASA Technical Reports Server (NTRS)

Cucinotta, F. A.; Wilson, J. W.

1995-01-01

Exposures in space consist of low-level background components from galactic cosmic rays (GCR), occasional intense-energetic solar-particle events, periodic passes through geomagnetic-trapped radiation, and exposure from possible onboard nuclear-propulsion engines. Risk models for astronaut exposure from such diverse components and modalities must be developed to assure adequate protection in future NASA missions. The low-level background exposures (GCR), including relativistic heavy ions (HZE), will be the ultimate limiting factor for astronaut career exposure. We consider herein a two-mutation, initiation-promotion, radiation-carcinogenesis model in mice in which the initiation stage is represented by a linear kinetics model of cellular repair/misrepair, including the track-structure model for heavy ion action cross-sections. The model is validated by comparison with the harderian gland tumor experiments of Alpen et al. for various ion beams. We apply the initiation-promotion model to exposures from galactic cosmic rays, using models of the cosmic-ray environment and heavy ion transport, and consider the effects of the age of the mice prior to and after the exposure and of the length of time in space on predictions of relative risk. Our results indicate that biophysical models of age-dependent radiation hazard will provide a better understanding of GCR risk than models that rely strictly on estimates of the initial slopes of these radiations.

Utility of the Measurement of Carboxyhemoglobin Level at the Site of Acute Carbon Monoxide Poisoning in Rural Areas.

PubMed

Onodera, Makoto; Fujino, Yasuhisa; Kikuchi, Satoshi; Sato, Masayuki; Mori, Kiyofumi; Beppu, Takaaki; Inoue, Yoshihiro

2016-01-01

Objective. This study examined the hypothesis that correlations exist between the carbon monoxide exposure time and the carboxyhemoglobin concentration at the site of carbon monoxide poisoning, using a pulse carbon monoxide oximeter in rural areas or the carboxyhemoglobin concentration measured at a given medical institution. Background. In previous studies, no definitive relationships between the arterial blood carboxyhemoglobin level and the severity of carbon monoxide poisoning have been observed. Method. The subjects included patients treated for acute carbon monoxide poisoning in whom a medical emergency team was able to measure the carboxyhemoglobin level at the site of poisoning. We examined the relationship between the carboxyhemoglobin level at the site of poisoning and carbon monoxide exposure time and the relationships between the arterial blood carboxyhemoglobin level and carbon monoxide exposure time. Results. A total of 10 patients met the above criteria. The carboxyhemoglobin levels at the site of poisoning were significantly and positively correlated with the exposure time (rs = 0.710, p = 0.021), but the arterial blood carboxyhemoglobin levels were not correlated with the exposure time. Conclusion. In rural areas, the carboxyhemoglobin level measured at the site of carbon monoxide poisoning correlated with the exposure time.

Effect of urban traffic, individual habits, and genetic polymorphisms on background urinary 1-hydroxypyrene excretion.

PubMed

Cocco, Pierluigi; Moore, Patrick S; Ennas, Maria G; Tocco, Maria G; Ibba, Antonio; Mattuzzi, Silvia; Meloni, Michele; Monne, Maria; Piras, Giovanna; Collu, Stefania; Satta, Giannina; Zucca, Mariagrazia; Scarpa, Aldo; Flore, Costantino

2007-01-01

Potential sources of exposure to polycyclic aromatic hydrocarbons (PAHs) and genetic polymorphisms were investigated in relation to their contribution to interindividual variation in baseline levels of urinary 1-hydroxypyrene (1-OHP) excretion in subjects without occupational exposure to PAHs. Urinary excretion of 1-OHP was measured in 114 subjects, including 48 women and 66 men. Questionnaire information was collected on possible environmental and individual sources of PAH exposure. A subset of 70 individuals also was evaluated for a single-nucleotide polymorphism (Ex7+295C-->T) in the cytochrome P-450 1A2 (CYP1A2) gene, and 61 of these also were evaluated for the glutathione transferase T1 (GSTT1) gene polymorphism. 1-OHP values did not show a significant seasonal variability and were unaffected by age; education; body mass index; smoking status, including passive smoking; or the C-->T base substitution in position 295 of exon 7 of the CYP1A2 gene. After reciprocal adjustment with logistic regression, living in a heavily trafficked urban area (odds ratio, 4.9; 95% confidence interval, 1.0-24.9), and frequent intake of grilled meat (odds ratio, 6.9; 95% confidence interval, 1.1-43.5) were significant predictors of background urinary 1-OHP levels of 0.50 microg/g creatinine or greater. Elevated risks also were associated with daily alcohol intake greater than 65 g and the nonnull GSTT1 genotype. Our study shows that exposure to urban traffic, dietary habits, and the nonnull GSTT1 genotype may contribute to interindividual variation in background levels of 1-OHP urinary excretion in subjects without occupational exposure to PAHs.

An aerial radiological survey of the Durango, Colorado uranium mill tailings site and surrounding area

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hilton, L.K.

1981-06-01

An aerial radiological survey of Durango, Colorado, including the inactive uranium mill tailings piles located southwest of the town, was conducted during August 25--29, 1980, for the Department of Energy's Environmental and Safety Engineering Division. Areas of radiation exposure rates higher than the local background, which was about 15 microrentgens per hour ({mu}R/h), were observed directly over and to the south of the mill tailings piles, over a cemetery, and at two spots near the fairgrounds. The rapidly changing radiation exposure rates at the boundaries of the piles preclude accurate extrapolation of aerial radiological data to ground level exposure ratesmore » in their immediate vicinity. Estimated radiation exposure rates close to the piles, however, approached 30 times background, or about 450 {mu}R/h. Radiation exposure rates in a long area extending south from the tailings piles were about 25 {mu}R/h.« less

Dark Matter Results from 54-Ton-Day Exposure of PandaX-II Experiment

NASA Astrophysics Data System (ADS)

Cui, Xiangyi; Abdukerim, Abdusalam; Chen, Wei; Chen, Xun; Chen, Yunhua; Dong, Binbin; Fang, Deqing; Fu, Changbo; Giboni, Karl; Giuliani, Franco; Gu, Linhui; Gu, Yikun; Guo, Xuyuan; Guo, Zhifan; Han, Ke; He, Changda; Huang, Di; He, Shengming; Huang, Xingtao; Huang, Zhou; Ji, Xiangdong; Ju, Yonglin; Li, Shaoli; Li, Yao; Lin, Heng; Liu, Huaxuan; Liu, Jianglai; Ma, Yugang; Mao, Yajun; Ni, Kaixiang; Ning, Jinhua; Ren, Xiangxiang; Shi, Fang; Tan, Andi; Wang, Cheng; Wang, Hongwei; Wang, Meng; Wang, Qiuhong; Wang, Siguang; Wang, Xiuli; Wang, Xuming; Wu, Qinyu; Wu, Shiyong; Xiao, Mengjiao; Xie, Pengwei; Yan, Binbin; Yang, Yong; Yue, Jianfeng; Zhang, Dan; Zhang, Hongguang; Zhang, Tao; Zhang, Tianqi; Zhao, Li; Zhou, Jifang; Zhou, Ning; Zhou, Xiaopeng; PandaX-II Collaboration

2017-11-01

We report a new search for weakly interacting massive particles (WIMPs) using the combined low background data sets acquired in 2016 and 2017 from the PandaX-II experiment in China. The latest data set contains a new exposure of 77.1 live days, with the background reduced to a level of 0.8 ×10-3 evt /kg /day , improved by a factor of 2.5 in comparison to the previous run in 2016. No excess events are found above the expected background. With a total exposure of 5.4 ×104 kg day , the most stringent upper limit on the spin-independent WIMP-nucleon cross section is set for a WIMP with mass larger than 100 GeV /c2 , with the lowest 90% C.L. exclusion at 8.6 ×10-47 cm2 at 40 GeV /c2 .

Perfluoroalkyl Substances During Pregnancy and Validated Preeclampsia Among Nulliparous Women in the Norwegian Mother and Child Cohort Study

PubMed Central

Starling, Anne P.; Engel, Stephanie M.; Richardson, David B.; Baird, Donna D.; Haug, Line S.; Stuebe, Alison M.; Klungsøyr, Kari; Harmon, Quaker; Becher, Georg; Thomsen, Cathrine; Sabaredzovic, Azemira; Eggesbø, Merete; Hoppin, Jane A.; Travlos, Gregory S.; Wilson, Ralph E.; Trogstad, Lill I.; Magnus, Per; Longnecker, Matthew P.

2014-01-01

Perfluoroalkyl substances (PFAS) are persistent and ubiquitous environmental contaminants, and human exposure to these substances may be related to preeclampsia, a common pregnancy complication. Previous studies have found serum concentrations of PFAS to be positively associated with pregnancy-induced hypertension and preeclampsia in a population with high levels of exposure to perfluorooctanoate. Whether this association exists among pregnant women with background levels of PFAS exposure is unknown. Using data from the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health, we carried out a study of nulliparous pregnant women enrolled in 2003–2007 (466 cases, 510 noncases) to estimate associations between PFAS concentrations and an independently validated diagnosis of preeclampsia. We measured levels of 9 PFAS in maternal plasma extracted midpregnancy; statistical analyses were restricted to 7 PFAS that were quantifiable in more than 50% of samples. In proportional hazards models adjusted for maternal age, prepregnancy body mass index (weight (kg)/height (m)2), educational level, and smoking status, we observed no strongly positive associations between PFAS levels and preeclampsia. We found an inverse association between preeclampsia and the highest quartile of perfluoroundecanoic acid concentration relative to the lowest quartile (hazard ratio = 0.55, 95% confidence interval: 0.38, 0.81). Overall, our findings do not support an increased risk of preeclampsia among nulliparous Norwegian women with background levels of PFAS exposure. PMID:24557813

Sex-specific differences in effect of prenatal exposure to dioxin-like compounds on neurodevelopment in Japanese children: Sapporo cohort study.

PubMed

Nakajima, Sonomi; Saijo, Yasuaki; Miyashita, Chihiro; Ikeno, Tamiko; Sasaki, Seiko; Kajiwara, Junboku; Kishi, Reiko

2017-11-01

Consistent reports are not available on the effects of dioxin-like polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (PCDD)/ polychlorinated dibenzofurans (PCDF) (dioxin-like compounds [DLCs]) on child neurodevelopment. Further, the effect of background-level exposure to individual DLC isomers is not known. We carried out the Sapporo cohort study to evaluate the effect of prenatal exposure to each DLC isomer on child neurodevelopment at 6 and 18 months of age, and assessed sex-specific differences in these effects. The levels of all and each individual DLC isomers were estimated in maternal peripheral blood. Neurodevelopment was evaluated using the Bayley Scales of Infant Development-2nd Edition for 6-month-old infants (n = 190) and 18-month-old children (n = 121). In male children, levels of 10 DLC isomers were significantly negatively associated with the Psychomotor Developmental Index (PDI) at 6 months of age after adjustment for potential confounding variables. However, at 18 months of age, these associations were absent. In female children, the level of only one DLC isomer was significantly negatively associated with PDI at 6 months of age. However, in contrast to the male children, the levels of six DLC isomers in 18-month-old female children were significantly positively associated with the Mental Developmental Index. These findings indicate that adverse neurodevelopmental effects of prenatal background-level exposure to DLCs may be stronger in male children. Copyright © 2017 Elsevier Inc. All rights reserved.

Soudan Low Background Counting Facility (SOLO)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Attisha, Michael; Viveiros, Luiz de; Gaitksell, Richard

2005-09-08

The Soudan Low Background Counting Facility (SOLO) has been in operation at the Soudan Mine, MN since March 2003. In the past two years, we have gamma-screened samples for the Majorana, CDMS and XENON experiments. With individual sample exposure times of up to two weeks we have measured sample contamination down to the 0.1 ppb level for 238U / 232Th, and down to the 0.25 ppm level for 40K.

CHANGES IN GENE EXPRESSION PROFILE IN THE CEREBELLUM AND THE HIPPOCAMPUS FOLLOWING DEVELOPMENTAL EXPOSURE TO A NEUROTOXICANT.

EPA Science Inventory

The vast literature on the group of chemicals known as polychlorinated biphenyls (PCBs) makes it a unique model to understand major issues related to environmental mixtures of persistent chemicals. At background levels of exposure, PCBs have been shown to affect human health incl...

Diesel exhaust and lung cancer in the trucking industry: exposure-response analyses and risk assessment.

PubMed

Steenland, K; Deddens, J; Stayner, L

1998-09-01

Diesel exhaust is considered a probable human carcinogen by the International Agency for Research on Cancer (IARC). The epidemiologic evidence rests on studies of lung cancer among truck drivers, bus drivers, shipyard workers, and railroad workers. The general public is exposed to diesel exhaust in ambient air. Two regulatory agencies are now considering regulating levels of diesel exhaust: the California EPA (ambient levels) and the Mine Safety Health Administration (MSHA) (occupational levels). To date, there have been few quantitative exposure-response analyses of diesel and lung cancer based on human data. We conducted exposure-response analyses among workers in the trucking industry, adjusted for smoking. Diesel exhaust exposure was estimated based on a 1990 industrial hygiene survey. Past exposures were estimated assuming that they were a function of 1) the number of heavy duty trucks on the road, 2) the particulate emissions (grams/mile) of diesel engines over time, and 3) leaks from trucks' exhaust systems for long-haul drivers. Regardless of assumptions about past exposure, all analyses resulted in significant positive trends in lung cancer risk with increasing cumulative exposure. A male truck driver exposed to 5 micrograms/m3 of elemental carbon (a typical exposure in 1990, approximately five times urban background levels) would have a lifetime excess risk of lung cancer of 1-2% above a background risk of 5%. We found a lifetime excess risk ten times higher than the 1 per 1,000 excess risk allowed by OSHA in setting regulations. There are about 2.8 million truck drivers in the U.S. Our results depend on estimates about unknown past exposures, and should be viewed as exploratory. They conform reasonably well to recent estimates for diesel-exposed railroad workers done by the California EPA, although those results themselves have been disputed.

Health Inequalities among Workers with a Foreign Background in Sweden: Do Working Conditions Matter?

PubMed Central

Dunlavy, Andrea C.; Rostila, Mikael

2013-01-01

Employment and working conditions are key social determinants of health, yet current information is lacking regarding relationships between foreign background status, working conditions and health among workers in Sweden. This study utilized cross-sectional data from the 2010 Swedish Level of Living Survey (LNU) and the Level of Living Survey for Foreign Born Persons and their Children (LNU-UFB) to assess whether or not health inequalities exist between native Swedish and foreign background workers and if exposure to adverse psychosocial and physical working conditions contributes to the risk for poor health among foreign background workers. A sub-sample of 4,021 employed individuals aged 18–65 was analyzed using logistic regression. Eastern European, Latin American and Other Non-Western workers had an increased risk of both poor self-rated health and mental distress compared to native Swedish workers. Exposure to adverse working conditions only minimally influenced the risk of poor health. Further research should examine workers who are less integrated or who have less secure labor market attachments and also investigate how additional working conditions may influence associations between health and foreign background status. PMID:23846669

An Assessment of Potential Exposure and Risk from Estrogens in Drinking Water

PubMed Central

Caldwell, Daniel J.; Mastrocco, Frank; Nowak, Edward; Johnston, James; Yekel, Harry; Pfeiffer, Danielle; Hoyt, Marilyn; DuPlessie, Beth M.; Anderson, Paul D.

2010-01-01

Background Detection of estrogens in the environment has raised concerns in recent years because of their potential to affect both wildlife and humans. Objectives We compared exposures to prescribed and naturally occurring estrogens in drinking water to exposures to naturally occurring background levels of estrogens in the diet of children and adults and to four independently derived acceptable daily intakes (ADIs) to determine whether drinking water intakes are larger or smaller than dietary intake or ADIs. Methods We used the Pharmaceutical Assessment and Transport Evaluation (PhATE) model to predict concentrations of estrogens potentially present in drinking water. Predicted drinking water concentrations were combined with default water intake rates to estimate drinking water exposures. Predicted drinking water intakes were compared to dietary intakes and also to ADIs. We present comparisons for individual estrogens as well as combined estrogens. Results In the analysis we estimated that a child’s exposures to individual prescribed estrogens in drinking water are 730–480,000 times lower (depending upon estrogen type) than exposure to background levels of naturally occurring estrogens in milk. A child’s exposure to total estrogens in drinking water (prescribed and naturally occurring) is about 150 times lower than exposure from milk. Adult margins of exposure (MOEs) based on total dietary exposure are about 2 times smaller than those for children. Margins of safety (MOSs) for an adult’s exposure to total prescribed estrogens in drinking water vary from about 135 to > 17,000, depending on ADI. MOSs for exposure to total estrogens in drinking water are about 2 times lower than MOSs for prescribed estrogens. Depending on the ADI that is used, MOSs for young children range from 28 to 5,120 for total estrogens (including both prescribed and naturally occurring sources) in drinking water. Conclusions The consistently large MOEs and MOSs strongly suggest that prescribed and total estrogens that may potentially be present in drinking water in the United States are not causing adverse effects in U.S. residents, including sensitive subpopulations. PMID:20194073

Resistance of Feather-Associated Bacteria to Intermediate Levels of Ionizing Radiation near Chernobyl

PubMed Central

Ruiz-González, Mario Xavier; Czirják, Gábor Árpád; Genevaux, Pierre; Møller, Anders Pape; Mousseau, Timothy Alexander; Heeb, Philipp

2016-01-01

Ionizing radiation has been shown to produce negative effects on organisms, although little is known about its ecological and evolutionary effects. As a study model, we isolated bacteria associated with feathers from barn swallows Hirundo rustica from three study areas around Chernobyl differing in background ionizing radiation levels and one control study site in Denmark. Each bacterial community was exposed to four different γ radiation doses ranging from 0.46 to 3.96 kGy to test whether chronic exposure to radiation had selected for resistant bacterial strains. Experimental radiation duration had an increasingly overall negative effect on the survival of all bacterial communities. After exposure to γ radiation, bacteria isolated from the site with intermediate background radiation levels survived better and produced more colonies than the bacterial communities from other study sites with higher or lower background radiation levels. Long-term effects of radiation in natural populations might be an important selective pressure on traits of bacteria that facilitate survival in certain environments. Our findings indicate the importance of further studies to understand the proximate mechanisms acting to buffer the negative effects of ionizing radiation in natural populations. PMID:26976674

Resistance of Feather-Associated Bacteria to Intermediate Levels of Ionizing Radiation near Chernobyl.

PubMed

Ruiz-González, Mario Xavier; Czirják, Gábor Árpád; Genevaux, Pierre; Møller, Anders Pape; Mousseau, Timothy Alexander; Heeb, Philipp

2016-03-15

Ionizing radiation has been shown to produce negative effects on organisms, although little is known about its ecological and evolutionary effects. As a study model, we isolated bacteria associated with feathers from barn swallows Hirundo rustica from three study areas around Chernobyl differing in background ionizing radiation levels and one control study site in Denmark. Each bacterial community was exposed to four different γ radiation doses ranging from 0.46 to 3.96 kGy to test whether chronic exposure to radiation had selected for resistant bacterial strains. Experimental radiation duration had an increasingly overall negative effect on the survival of all bacterial communities. After exposure to γ radiation, bacteria isolated from the site with intermediate background radiation levels survived better and produced more colonies than the bacterial communities from other study sites with higher or lower background radiation levels. Long-term effects of radiation in natural populations might be an important selective pressure on traits of bacteria that facilitate survival in certain environments. Our findings indicate the importance of further studies to understand the proximate mechanisms acting to buffer the negative effects of ionizing radiation in natural populations.

Concerns with low-level ionizing radiation.

PubMed

Yalow, R S

1994-05-01

To clarify the effects of ionizing radiation and to dispel fear associated with the use of radioactivity in medical diagnosis and therapy. Studies of populations in geographic areas of increased cosmic radiation and high natural background radiation, radiation-exposed workers, patients with medical exposure to radioactivity, and accidental exposure are reviewed. No reproducible evidence shows harmful effects associated with increases in background radiation of 3 to 10 times the usual levels. American military personnel who participated in nuclear testing had no increase in leukemia or other cancers. Among 22,000 patients with hyperthyroidism treated with 131I (mean dose, 10 rem), no increased incidence of leukemia was found in comparison with 14,000 similar patients who received other treatment. A 20-year follow-up of 35,000 patients who underwent 131I uptake tests for evaluation of thyroid function revealed that those studied for other than a suspected tumor had only 60% of the thyroid cancers expected in a control group. Although early studies showed that high exposures to miners to radon and its daughters resulted in a substantial increase in lung cancer, no evidence exists for an increase in lung cancer among nonsmokers exposed to increased radon levels in the home. Perhaps the association of radiation with the atomic bomb has created a climate of fear about the possible dangers of radiation at any level; however, no evidence indicates that current radiation exposures associated with medical usage are harmful.

Peripheral Blood Signatures of Lead Exposure

PubMed Central

LaBreche, Heather G.; Meadows, Sarah K.; Nevins, Joseph R.; Chute, John P.

2011-01-01

Background Current evidence indicates that even low-level lead (Pb) exposure can have detrimental effects, especially in children. We tested the hypothesis that Pb exposure alters gene expression patterns in peripheral blood cells and that these changes reflect dose-specific alterations in the activity of particular pathways. Methodology/Principal Finding Using Affymetrix Mouse Genome 430 2.0 arrays, we examined gene expression changes in the peripheral blood of female Balb/c mice following exposure to per os lead acetate trihydrate or plain drinking water for two weeks and after a two-week recovery period. Data sets were RMA-normalized and dose-specific signatures were generated using established methods of supervised classification and binary regression. Pathway activity was analyzed using the ScoreSignatures module from GenePattern. Conclusions/Significance The low-level Pb signature was 93% sensitive and 100% specific in classifying samples a leave-one-out crossvalidation. The high-level Pb signature demonstrated 100% sensitivity and specificity in the leave-one-out crossvalidation. These two signatures exhibited dose-specificity in their ability to predict Pb exposure and had little overlap in terms of constituent genes. The signatures also seemed to reflect current levels of Pb exposure rather than past exposure. Finally, the two doses showed differential activation of cellular pathways. Low-level Pb exposure increased activity of the interferon-gamma pathway, whereas high-level Pb exposure increased activity of the E2F1 pathway. PMID:21829687

Comparison of Personal PM2.5 Exposure in Various Micro-Environments during Haze and Clean Days in Nanjing

NASA Astrophysics Data System (ADS)

Zhang, T.

2015-12-01

There is a long term trend of haze in East China. As a main component of haze, fine particle (PM2.5) in various micro-environments (MEs) is a cause for concern regarding the environment and public health. To estimate individual PM2.5 exposures in distinct, non-residential MEs and to determine exposure characteristics during haze and clean days, we conducted personal PM2.5 monitoring with portable PM2.5 personal environment monitors (MicroPEM) in 19 indoor/outdoor MEs in Nanjing, and compared personal exposure data with ambient PM2.5 levels. Personal PM2.5 exposure patterns displayed notable spatial variance, peaking in snack streets and restaurants and dipping in subways and labs. Under both haze and non-haze conditions, different characteristics of MEs and the background PM2.5 level jointly determine the spatial variance of individual exposure. Indoor MEs with better ventilation systems led to lower personal PM2.5 exposure levels. During haze days, impact from high ambient PM2.5 overwhelms influence from other factors and dominates personal exposure trends.

Mother and Child Reports of Hurricane Related Stressors: Data from a Sample of Families Exposed to Hurricane Katrina

ERIC Educational Resources Information Center

Lai, Betty S.; Beaulieu, Brooke; Ogokeh, Constance E.; Self-Brown, Shannon; Kelley, Mary Lou

2015-01-01

Background: Families exposed to disasters such as Hurricane Katrina are at risk for numerous adverse outcomes. While previous literature suggests that the degree of disaster exposure corresponds with experiencing negative outcomes, it is unclear if parents and children report similar levels of disaster exposure. Objective: The purpose of this…

Is Prenatal Alcohol Exposure Related to Inattention and Hyperactivity Symptoms in Children? Disentangling the Effects of Social Adversity

ERIC Educational Resources Information Center

Rodriguez, A.; Olsen, J.; Kotimaa, A. J.; Kaakinen, M.; Moilanen, I.; Henriksen, T. B.; Linnet, K. M.; Miettunen, J.; Obel, C.; Taanila, A.; Ebeling, H.; Jarvelin, M. R.

2009-01-01

Background: Studies concerning whether exposure to low levels of maternal alcohol consumption during fetal development is related to child inattention and hyperactivity symptoms have shown conflicting results. We examine the contribution of covariates related to social adversity to resolve some inconsistencies in the extant research by conducting…

Tinnitus

MedlinePlus

... Sound therapies that involve simple things like background music or noise or specialized ear level maskers may ... exposure to high intensity sounds, specifically listening to music. In particular, virtually all teenagers use personal MP3 ...

Level of Intrauterine Cocaine Exposure and Neuropsychological Test Scores in Preadolescence: Subtle Effects on Auditory Attention and Narrative Memory

PubMed Central

Beeghly, Marjorie; Rose-Jacobs, Ruth; Martin, Brett M.; Cabral, Howard J.; Heeren, Timothy C.; Frank, Deborah A.

2014-01-01

Neuropsychological processes such as attention and memory contribute to children's higher-level cognitive and language functioning and predict academic achievement. The goal of this analysis was to evaluate whether level of intrauterine cocaine exposure (IUCE) alters multiple aspects of preadolescents' neuropsychological functioning assessed using a single age-referenced instrument, the NEPSY: A Developmental Neuropsychological Assessment (NEPSY) [71], after controlling for relevant covariates. Participants included 137 term 9.5-year-old children from low-income urban backgrounds (51% male, 90% African American/Caribbean) from an ongoing prospective longitudinal study. Level of IUCE was assessed in the newborn period using infant meconium and maternal report. 52% of the children had IUCE (65% with lighter IUCE, and 35% with heavier IUCE), and 48% were unexposed. Infants with Fetal Alcohol Syndrome, HIV seropositivity, or intrauterine exposure to illicit substances other than cocaine and marijuana were excluded. At the 9.5-year follow-up visit, trained examiners masked to IUCE and background variables evaluated children's neuropsychological functioning using the NEPSY. The association between level of IUCE and NEPSY outcomes was evaluated in a series of linear regressions controlling for intrauterine exposure to other substances and relevant child, caregiver, and demographic variables. Results indicated that level of IUCE was associated with lower scores on the Auditory Attention and Narrative Memory tasks, both of which require auditory information processing and sustained attention for successful performance. However, results did not follow the expected ordinal, dose-dependent pattern. Children's neuropsychological test scores were also altered by a variety of other biological and psychosocial factors. PMID:24978115

49 CFR 227.109 - Audiometric testing program.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Measurements of background sound pressure levels in the audiometric test room as required in appendix D of this... occupational noise in excess of the action level. Hearing protectors may be used as a substitute for the... railroad shall notify its employees of the need to avoid high levels of non-occupational noise exposure...

Measuring electromagnetic fields (EMF) around wind turbines in Canada: is there a human health concern?

PubMed Central

2014-01-01

Background The past five years has seen considerable expansion of wind power generation in Ontario, Canada. Most recently worries about exposure to electromagnetic fields (EMF) from wind turbines, and associated electrical transmission, has been raised at public meetings and legal proceedings. These fears have not been based on any actual measurements of EMF exposure surrounding existing projects but appear to follow from worries from internet sources and misunderstanding of the science. Methods The study was carried out at the Kingsbridge 1 Wind Farm located near Goderich, Ontario, Canada. Magnetic field measurements were collected in the proximity of 15 Vestas 1.8 MW wind turbines, two substations, various buried and overhead collector and transmission lines, and nearby homes. Data were collected during three operational scenarios to characterize potential EMF exposure: ‘high wind’ (generating power), ‘low wind’ (drawing power from the grid, but not generating power) and ‘shut off’ (neither drawing, nor generating power). Results Background levels of EMF (0.2 to 0.3 mG) were established by measuring magnetic fields around the wind turbines under the ‘shut off’ scenario. Magnetic field levels detected at the base of the turbines under both the ‘high wind’ and ‘low wind’ conditions were low (mean = 0.9 mG; n = 11) and rapidly diminished with distance, becoming indistinguishable from background within 2 m of the base. Magnetic fields measured 1 m above buried collector lines were also within background (≤ 0.3 mG). Beneath overhead 27.5 kV and 500 kV transmission lines, magnetic field levels of up to 16.5 and 46 mG, respectively, were recorded. These levels also diminished rapidly with distance. None of these sources appeared to influence magnetic field levels at nearby homes located as close as just over 500 m from turbines, where measurements immediately outside of the homes were ≤ 0.4 mG. Conclusions The results suggest that there is nothing unique to wind farms with respect to EMF exposure; in fact, magnetic field levels in the vicinity of wind turbines were lower than those produced by many common household electrical devices and were well below any existing regulatory guidelines with respect to human health. PMID:24529028

[Effects of exposure frequency and background information on preferences for photographs of cars in different locations].

PubMed

Matsuda, Ken; Kusumi, Takashi; Hosomi, Naohiro; Osa, Atsushi; Miike, Hidetoshi

2014-08-01

This study examined the influence of familiarity and novelty on the mere exposure effect while manipulating the presentation of background information. We selected presentation stimuli that integrated cars and backgrounds based on the results of pilot studies. During the exposure phase, we displayed the stimuli successively for 3 seconds, manipulating the background information (same or different backgrounds with each presentation) and exposure frequency (3, 6, and 9 times). In the judgment phase, 18 participants judged the cars in terms of preference, familiarity, and novelty on a 7-point scale. As the number of stimulus presentations increased, the preference for the cars increased during the different background condition and decreased during the same background condition. This increased preference may be due to the increase in familiarity caused by the higher exposure frequency and novelty resulting from the background changes per exposure session. The rise in preference judgments was not seen when cars and backgrounds were presented independently. Therefore, the addition of novel features to each exposure session facilitated the mere exposure effect.

An exposure and health risk assessment of lead (Pb) in lipstick.

PubMed

Monnot, Andrew D; Christian, Whitney V; Abramson, Matthew M; Follansbee, Mark H

2015-06-01

Lead (Pb) content in lipstick and other consumer products has become an increasing concern. In 2010, the United States Food and Drug Administration tested 400 lipstick samples and found a maximum Pb concentration of 7.19 ppm. To assess the safety of lipstick in adults that chronically apply lipstick as well as instances where children might incidentally ingest lipstick products, the United States Environmental Protection Agency's (US EPA) Adult Lead Model and Integrated Exposure Uptake Biokinetic Model for Lead in Children were used to determine the blood Pb concentrations of adults and children ingesting varying amounts of lipstick of different Pb concentrations. Modeled blood Pb concentrations were compared with oral ingestion guidelines and to the Centers for Disease Control and the US EPA's actionable blood Pb levels of 5 and 10 µg/dL. Background Pb exposure was the primary contributor to estimated blood Pb levels (BLLs) in children and adults, and Pb exposure from lipstick did not significantly increase estimated BLLs. These results suggest that the safety of consumer products and cosmetics should be assessed not only by the presence and amounts of hazardous contents, but also in conjunction with an assessment of estimated background exposures and comparison to health-based standards. Copyright © 2015 Elsevier Ltd. All rights reserved.

Exposure of German residents to ethylene and propylene glycol ethers in general and after cleaning scenarios.

PubMed

Fromme, H; Nitschke, L; Boehmer, S; Kiranoglu, M; Göen, T

2013-03-01

Glycol ethers are a class of semi-volatile substances used as solvents in a variety of consumer products like cleaning agents, paints, cosmetics as well as chemical intermediates. We determined 11 metabolites of ethylene and propylene glycol ethers in 44 urine samples of German residents (background level study) and in urine samples of individuals after exposure to glycol ethers during cleaning activities (exposure study). In the study on the background exposure, methoxyacetic acid and phenoxyacetic acid (PhAA) could be detected in each urine sample with median (95th percentile) values of 0.11 mgL(-1) (0.30 mgL(-1)) and 0.80 mgL(-1) (23.6 mgL(-1)), respectively. The other metabolites were found in a limited number of samples or in none. In the exposure study, 5-8 rooms were cleaned with a cleaner containing ethylene glycol monobutyl ether (EGBE), propylene glycol monobutyl ether (PGBE), or ethylene glycol monopropyl ether (EGPE). During cleaning the mean levels in the indoor air were 7.5 mgm(-3) (EGBE), 3.0 mgm(-3) (PGBE), and 3.3 mgm(-3) (EGPE), respectively. The related metabolite levels analysed in the urine of the residents of the rooms at the day of cleaning were 2.4 mgL(-1) for butoxyacetic acid, 0.06 mgL(-1) for 2-butoxypropionic acid, and 2.3 mgL(-1) for n-propoxyacetic acid. Overall, our study indicates that the exposure of the population to glycol ethers is generally low, with the exception of PhAA. Moreover, the results of the cleaning scenarios demonstrate that the use of indoor cleaning agents containing glycol ethers can lead to a detectable internal exposure of residents. Copyright © 2012 Elsevier Ltd. All rights reserved.

An aerial radiological survey of the Durango, Colorado uranium mill tailings site and surrounding area. Date of survey: August 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hilton, L.K.

1981-06-01

An aerial radiological survey of Durango, Colorado, including the inactive uranium mill tailings piles located southwest of the town, was conducted during August 25--29, 1980, for the Department of Energy`s Environmental and Safety Engineering Division. Areas of radiation exposure rates higher than the local background, which was about 15 microrentgens per hour ({mu}R/h), were observed directly over and to the south of the mill tailings piles, over a cemetery, and at two spots near the fairgrounds. The rapidly changing radiation exposure rates at the boundaries of the piles preclude accurate extrapolation of aerial radiological data to ground level exposure ratesmore » in their immediate vicinity. Estimated radiation exposure rates close to the piles, however, approached 30 times background, or about 450 {mu}R/h. Radiation exposure rates in a long area extending south from the tailings piles were about 25 {mu}R/h.« less

An accurate laser radiometer for determining visible exposure times.

PubMed

Royston, D D

1985-01-01

A laser light radiometer has been developed for the Electro-Optics Branch of the Center for Devices and Radiological Health (CDRH). The radiometer measures direct laser radiation emitted in the visible spectrum. Based upon this measurement, the instrument's microprocessor automatically determines at what time duration the exposure to the measured laser radiation would exceed either the class I accessible emission limits of the Federal Performance Standard for laser products or the maximum permissible exposure limits of laser user safety standards. The instrument also features automatic background level compensation, pulse measurement capability, and self-diagnosis. Measurement of forward surface illumination levels preceding HpD photoradiation therapy is possible.

Investigation of Deuterium Loaded Materials Subject to X-Ray Exposure

NASA Technical Reports Server (NTRS)

Benyo, Theresa L.; Steinetz, Bruce M.; Hendricks, Robert C.; Martin, Richard E.; Forsley, Lawrence P.; Daniels, Christopher C.; Chait, Arnon; Pines, Vladimir; Pines, Marianna; Penney, Nicholas;

Dark Matter Results from 54-Ton-Day Exposure of PandaX-II Experiment.

PubMed

Cui, Xiangyi; Abdukerim, Abdusalam; Chen, Wei; Chen, Xun; Chen, Yunhua; Dong, Binbin; Fang, Deqing; Fu, Changbo; Giboni, Karl; Giuliani, Franco; Gu, Linhui; Gu, Yikun; Guo, Xuyuan; Guo, Zhifan; Han, Ke; He, Changda; Huang, Di; He, Shengming; Huang, Xingtao; Huang, Zhou; Ji, Xiangdong; Ju, Yonglin; Li, Shaoli; Li, Yao; Lin, Heng; Liu, Huaxuan; Liu, Jianglai; Ma, Yugang; Mao, Yajun; Ni, Kaixiang; Ning, Jinhua; Ren, Xiangxiang; Shi, Fang; Tan, Andi; Wang, Cheng; Wang, Hongwei; Wang, Meng; Wang, Qiuhong; Wang, Siguang; Wang, Xiuli; Wang, Xuming; Wu, Qinyu; Wu, Shiyong; Xiao, Mengjiao; Xie, Pengwei; Yan, Binbin; Yang, Yong; Yue, Jianfeng; Zhang, Dan; Zhang, Hongguang; Zhang, Tao; Zhang, Tianqi; Zhao, Li; Zhou, Jifang; Zhou, Ning; Zhou, Xiaopeng

2017-11-03

We report a new search for weakly interacting massive particles (WIMPs) using the combined low background data sets acquired in 2016 and 2017 from the PandaX-II experiment in China. The latest data set contains a new exposure of 77.1 live days, with the background reduced to a level of 0.8×10^{-3}  evt/kg/day, improved by a factor of 2.5 in comparison to the previous run in 2016. No excess events are found above the expected background. With a total exposure of 5.4×10^{4}  kg day, the most stringent upper limit on the spin-independent WIMP-nucleon cross section is set for a WIMP with mass larger than 100  GeV/c^{2}, with the lowest 90% C.L. exclusion at 8.6×10^{-47}  cm^{2} at 40  GeV/c^{2}.

Uptake and depuration of PCB-153 in edible shrimp Palaemonetes varians and human health risk assessment.

PubMed

Grilo, T F; Cardoso, P G; Pato, P; Duarte, A C; Pardal, M A

2014-03-01

A medium-term mesocosm exposure study was conducted to elucidate bioaccumulation and depuration of polychlorinated biphenyl congener 153 (PCB-153) in edible shrimp Palaemonetes varians. Over the 15-day exposure period, shrimp under different exposure concentrations exhibited a significant increase in PCB-153 concentration compared with control organisms. Distinct bioaccumulation patterns and uptake rates were observed depending on the exposure concentrations. For low PCB-153 exposure levels (0.25μgL(-1)), accumulation followed a saturation model, reaching an apparent steady state after fifteen days exposure. For intermediate (2.5μgL(-1)) and high PCB-153 levels (25μgL(-1)), accumulation was faster and linear. In addition, the bioaccumulation rate was not proportional to PCB-153 concentration, and the bioaccumulation was higher at intermediate exposure concentrations. Regarding the depuration phase, P. varians lost up to 30% of PCB-153 after 72h and levels continued slowly to decrease until the end of the 30-d experimental period. However, PCB-153 levels in shrimp did not reach background values, and those exposed to moderate and high PCB-153 concentrations presented contamination levels much higher than the regulatory limit for human food consumption (75ngg(-1) ww for Σ6 PCB). Copyright © 2013 Elsevier Inc. All rights reserved.

Cadmium, mercury, and lead in kidney cortex of living kidney donors: Impact of different exposure sources,

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barregard, Lars, E-mail: lars.barregard@amm.gu.se; Fabricius-Lagging, Elisabeth; Lundh, Thomas

Background: Most current knowledge on kidney concentrations of nephrotoxic metals like cadmium (Cd), mercury (Hg), or lead (Pb) comes from autopsy studies. Assessment of metal concentrations in kidney biopsies from living subjects can be combined with information about exposure sources like smoking, diet, and occupation supplied by the biopsied subjects themselves. Objectives: To determine kidney concentrations of Cd, Hg, and Pb in living kidney donors, and assess associations with common exposure sources and background factors. Methods: Metal concentrations were determined in 109 living kidney donors aged 24-70 years (median 51), using inductively coupled plasma-mass spectrometry (Cd and Pb) and coldmore » vapor atomic fluorescence spectrometry (Hg). Smoking habits, occupation, dental amalgam, fish consumption, and iron stores were evaluated. Results: The median kidney concentrations were 12.9 {mu}g/g (wet weight) for cadmium, 0.21 {mu}g/g for mercury, and 0.08 {mu}g/g for lead. Kidney Cd increased by 3.9 {mu}g/g for a 10 year increase in age, and by 3.7 {mu}g/g for an extra 10 pack-years of smoking. Levels in non-smokers were similar to those found in the 1970s. Low iron stores (low serum ferritin) in women increased kidney Cd by 4.5 {mu}g/g. Kidney Hg increased by 6% for every additional amalgam surface, but was not associated with fish consumption. Lead was unaffected by the background factors surveyed. Conclusions: In Sweden, kidney Cd levels have decreased due to less smoking, while the impact of diet seems unchanged. Dental amalgam is the main determinant of kidney Hg. Kidney Pb levels are very low due to decreased exposure.« less

Overview of particulate exposures in the US trucking industry

PubMed Central

Smith, Thomas J.; Davis, Mary E.; Reaser, Paul; Natkin, Jonathan; Hart, Jaime E; Laden, Francine; Heff, Allan; Garshick, Eric

2007-01-01

As part of a large epidemiologic study of lung cancer, 55,000 subjects, we have conducted a nation-wide survey of particulate exposures in the US trucking industry. The goal is to differentiate the risks from various types of particulate exposures, such as traffic emissions and general air pollution. We hypothesize that exposures defined by job and work site characteristics can be linked with subjects using their personal job histories. This report covers exposures at 36 randomly sited large truck freight terminals in the US. Measurements were made of PM2.5, elemental carbon (EC), and organic carbon (OC) upwind of the terminal (background) and in work areas, and by personal samples. Significant differences in exposure intensity, dg/m3, were found for work locations and jobs relative to background levels (GM[GSD]) at terminal sites: PM2.5 9.8[2.34], EC 0.5[3.24], and OC 5.0[1.76]. Using EC as a marker for diesel particles, work locations varied significantly: office 0.3[3.7], dock area 0.7[2.89] and shop area 1.5[3.52]), as did job titles (non-smokers): clerk 0.1[9.98], dockworker 0.8[2.13], and mechanic 2.0[3.82]. Cigarette smoking contributed substantially to personal exposures, approximately doubling PM2.5 and OC, but having less of an effect on EC. Large differences were seen across the terminal sites due to differences in local regional air pollution levels from traffic and other sources. We conclude that it will be possible to estimate current exposures of the cohort using an exposure assignment matrix based on job title, work location, and terminal site. This distribution overlaps substantially with the general public’s exposure to these sources. PMID:16826284

Overview of particulate exposures in the US trucking industry.

PubMed

Smith, Thomas J; Davis, Mary E; Reaser, Paul; Natkin, Jonathan; Hart, Jaime E; Laden, Francine; Heff, Allan; Garshick, Eric

2006-07-01

As part of a large epidemiologic study of lung cancer, 55,000 subjects, we have conducted a nation-wide survey of particulate exposures in the US trucking industry. The goal is to differentiate the risks from various types of particulate exposures, such as traffic emissions and general air pollution. We hypothesize that exposures defined by job and work site characteristics can be linked with subjects using their personal job histories. This report covers exposures at 36 randomly chosen large truck freight terminals in the US. Measurements were made of PM2.5, elemental carbon (EC), and organic carbon (OC) upwind of the terminal (background) and in work areas, and by personal samples. Significant differences in exposure intensity, microg m(-3), were found for work locations and jobs relative to background levels (GM[GSD]) at terminal sites: PM2.5 9.8[2.34], EC 0.5[3.24], and OC 5.0[1.76]. Using EC as a marker for diesel particles, work locations varied significantly: office 0.3[3.7], dock area 0.7[2.89] and shop area 1.5[3.52]), as did job titles (non-smokers): clerk 0.1[9.98], dock worker 0.8[2.13], and mechanic 2.0[3.82]. Cigarette smoking contributed substantially to personal exposures, approximately doubling PM2.5 and OC, but having less of an effect on EC. Large differences were seen across the terminal sites due to differences in local regional air pollution levels from traffic and other sources. We conclude that it will be possible to estimate current exposures of the cohort using an exposure assignment matrix based on job title, work location, and terminal site. This distribution overlaps substantially with the general public's exposure to these sources.

Granularity of the Diffuse Background Observed

NASA Technical Reports Server (NTRS)

Gruber, D. E.; MacDonald, D.; Rothschild, R. E.; Boldt, E.; Mushotzky, R. F.; Fabian, A. C.

1995-01-01

First results are reported from a program for measuring the field-to-field fluctuation level of the cosmic diffuse background by using differences between the two background positions of each deep exposure with the High Energy X-ray Timing Experiment (HEXTE) instrument on the Remote X Ray Timing Explorer (RXTE). With 8 million live seconds accumulated to date a fluctuation level on the 15-25 keV band is observed which is consistent with extrapolations from the High Energy Astrophysical Observatory-1 (HEAO-1) measurements. Positive results are expected eventually at higher energies. Models of (active galactic nuclei) AGN origin will eventually be constrained by this program.

New Jersey Radium Research Project: final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharpe, W.D.

1979-01-01

Cancers among dead New Jersey subjects were almost three times the expected number. Their radiation experience apparently acted as a generalized carcinogen. Conventional clinical, laboratory and roentgenographic tests neither correlated with calculated radiation exposure nor predicted which subjects subsequently developed cancer. More subjects than expected were deaf and enough of the subjects had increased erythrocyte sedimentation rates and decreased alpha-1 serum globulin levels that both hearing tests and tests of immune competence should be undertaken among asymptomatic exposed populations at regular intervals to see whether these may indicate radiation effects prior to a fatal cancer or blood dyscrasia. If pre-terminalmore » radium-226 burdens validly express total irradiation experience, and past exposure to shorter-lived radium-228 (mesothorium) makes it unlikely that this is so, the distribution of radium osteitis among our subjects suggests that anatomically demonstrable radiation injury occurs in the vast majority of subjects with any radium-226 burden that can be measured above background levels after twenty-five years, and in almost half of those exposed whose measured radium-226 burdens are indistinguishable from background levels. Modification of the occupational exposure standard is recommended. (PCS)« less

Neurodevelopmental retardation, as assessed clinically and with magnetoencephalography and electroencephalography, associated with perinatal dioxin exposure.

PubMed

Ten Tusscher, G W; Leijs, M M; de Boer, L C C; Legler, J; Olie, K; Spekreijse, H; van Dijk, B W; Vulsma, T; Briët, J; Ilsen, A; Koppe, J G

2014-09-01

In 1980s Western Europe, human perinatal exposure to background levels of dioxins was rather high. We therefore evaluated the neurodevelopment of our cohort during the prepubertal period and in adolescence. At prepubertal age (7-12 years) 41 children were tested. Both neuromotor functioning and psychological testing were performed (Dutch version of the Wechsler Intelligence Scale for Children (WISC-R) and the Dutch version of the Child Behavior Checklist for ages 4-18 years (CBCL 4-18) and the Teacher Report Form (TRF)). Neurophysiological tests were performed using magnetoencephalography and electroencephalography. In adolescence (14-18 years) the behavior of 33 children was studied again (CBCL and TRF). And the levels of dioxins and dioxin-like PCBs (dl-PCBs) were measured in serum. At prepubertal age no association was found between perinatal dioxin exposure and verbal, performal and total IQ or with the Touwen's test for neuromotor development. There were behavioral problems associated with both prenatal and postnatal dioxin exposure. In adolescence there were problems associated with the current dioxin levels and dioxin-like-PCBs. Neurophysiological tests revealed clear negative dysfunction. An increase in latency time after a motion stimulus (N2b) of 13 ms (= a delay of 10%) is associated with the higher prenatal dioxin exposure. A similar delay was measured in testing cognitive ability by analyzing the odd ball measurements, N200 and P300, together with an amplitude decrease of 12 %. The delay is indicative of a defective myelinisation and the decrease in amplitude of a loss of neurons. We found effects on behavior in association with the perinatal dioxin exposure and in adolescence in association with the current dioxin levels. Neurophysiological testing is instrumental in the detection of effects of perinatal background levels of chemicals on brain development in normal, healthy children. The clinical, neurological and psychological tests commonly used are not sensitive enough to detect important effects. Copyright © 2014 Elsevier B.V. All rights reserved.

Risk of Erectile Dysfunction Induced by Arsenic Exposure through Well Water Consumption in Taiwan

PubMed Central

Hsieh, Fang-I; Hwang, Ti-Sheng; Hsieh, Yi-Chen; Lo, Hsiu-Chiung; Su, Chien-Tien; Hsu, Hui-Shing; Chiou, Hung-Yi; Chen, Chien-Jen

2008-01-01

Background Erectile dysfunction (ED) has a profound impact on the quality of life of many men. Many risk factors are associated with ED, such as aging, sex hormone levels, hypertension, cardiovascular diseases, and diabetes mellitus. Arsenic exposure could damage peripheral vessels and increase the risk of cardiovascular disease. However, the relationship between arsenic exposure and ED has seldom been evaluated. Objectives In this study we aimed to investigate whether exposure to arsenic enhances the risk of ED. Methods We recruited 177 males ≥ 50 years of age through health examinations conducted in three hospitals in Taiwan. We used a questionnaire (International Index of Erectile Function-5) to measure the level of erectile function. Sex hormones, including total testosterone and sex hormone–binding globulin, were determined by radioimmunoassay. We used another standardized questionnaire to collect background and behavioral information (e.g., cigarette smoking; alcohol, tea, or coffee drinking; and physical activity). Results The prevalence of ED was greater in the arsenic-endemic area (83.3%) than in the non–arsenic-endemic area (66.7%). Subjects with arsenic exposure > 50 ppb had a significantly higher risk of developing ED than those with exposure ≤ 50 ppb, after adjusting for age, cigarette smoking, diabetes mellitus, hypertension, and cardiovascular disease [odds ratio (OR) = 3.4]. Results also showed that the risk of developing severe ED was drastically enhanced by arsenic exposure (OR = 7.5), after adjusting for free testosterone and traditional risk factors of ED. Conclusions Results suggested that chronic arsenic exposure has a negative impact on erectile function. PMID:18414639

How do background ozone concentrations affect the biosynthesis of rosmarinic acid in Melissa officinalis?

PubMed

Döring, Anne S; Pellegrini, Elisa; Della Batola, Michele; Nali, Cristina; Lorenzini, Giacomo; Petersen, Maike

2014-03-01

Lemon balm (Melissa officinalis; Lamiaceae) plants were exposed to background ozone (O3) dosages (80ppb for 5h), because high background levels of O3 are considered to be as harmful as episodic O3 peaks. Immediately at the end of fumigation the plants appeared visually symptomless, but necrotic lesions were observed later. The biosynthesis of rosmarinic acid (RA) comprises eight enzymes, among them phenylalanine ammonia-lyase (PAL), 4-coumarate:coenzyme A ligase (4CL), tyrosine aminotransferase (TAT) and rosmarinic acid synthase (RAS). The transcript levels of these genes have been investigated by quantitative RT-PCR. There was a quick up-regulation of all genes at 3h of O3 exposure, but at 24h from beginning of exposure (FBE) only RAS and PAL were up-regulated. The specific activity of RAS was closely correlated with a decrease of RA concentration in lemon balm leaves. The specific activity of PAL increased at 12h FBE to 163% in comparison to control levels. This work provides insight into the effect of O3 stress on the formation of the main phenolic ingredient of the pharmaceutically important plant M. officinalis. Copyright © 2013 Elsevier GmbH. All rights reserved.

Human Lung Cancer Risks from Radon – Part II – Influence from Combined Adaptive Response and Bystander Effects – A Microdose Analysis

PubMed Central

Leonard, Bobby E.; Thompson, Richard E.; Beecher, Georgia C.

2010-01-01

In the prior Part I, the potential influence of the low level alpha radiation induced bystander effect (BE) on human lung cancer risks was examined. Recent analysis of adaptive response (AR) research results with a Microdose Model has shown that single low LET radiation induced charged particles traversals through the cell nucleus activates AR. We have here conducted an analysis based on what is presently known about adaptive response and the bystander effect (BE) and what new research is needed that can assist in the further evaluation human cancer risks from radon. We find that, at the UNSCEAR (2000) worldwide average human exposures from natural background and man-made radiations, the human lung receives about a 25% adaptive response protection against the radon alpha bystander damage. At the UNSCEAR (2000) minimum range of background exposure levels, the lung receives minimal AR protection but at higher background levels, in the high UNSCEAR (2000) range, the lung receives essentially 100% protection from both the radon alpha damage and also the endogenic, spontaneously occurring, potentially carcinogenic, lung cellular damage. PMID:22461760

PROUCL 4.0 SOFTWARE

EPA Science Inventory

Statistical inference, including both estimation and hypotheses testing approaches, is routinely used to: estimate environmental parameters of interest, such as exposure point concentration (EPC) terms, not-to-exceed values, and background level threshold values (BTVs) for contam...

Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing

PubMed Central

Zheng, Youfei; Li, Ting; Wei, Li; Guan, Qing

2018-01-01

Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m3, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS) threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00–4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively. PMID:29596366

Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing.

PubMed

Zhao, Hui; Zheng, Youfei; Li, Ting; Wei, Li; Guan, Qing

2018-03-29

Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m³, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS) threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00-4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively.

Aircraft and background noise annoyance effects

NASA Technical Reports Server (NTRS)

Willshire, K. F.

1984-01-01

To investigate annoyance of multiple noise sources, two experiments were conducted. The first experiment, which used 48 subjects, was designed to establish annoyance-noise level functions for three community noise sources presented individually: jet aircraft flyovers, air conditioner, and traffic. The second experiment, which used 216 subjects, investigated the effects of background noise on aircraft annoyance as a function of noise level and spectrum shape; and the differences between overall, aircraft, and background noise annoyance. In both experiments, rated annoyance was the dependent measure. Results indicate that the slope of the linear relationship between annoyance and noise level for traffic is significantly different from that of flyover and air conditioner noise and that further research was justified to determine the influence of the two background noises on overall, aircraft, and background noise annoyance (e.g., experiment two). In experiment two, total noise exposure, signal-to-noise ratio, and background source type were found to have effects on all three types of annoyance. Thus, both signal-to-noise ratio, and the background source must be considered when trying to determine community response to combined noise sources.

Measuring electromagnetic fields (EMF) around wind turbines in Canada: is there a human health concern?

PubMed

McCallum, Lindsay C; Whitfield Aslund, Melissa L; Knopper, Loren D; Ferguson, Glenn M; Ollson, Christopher A

2014-02-15

The past five years has seen considerable expansion of wind power generation in Ontario, Canada. Most recently worries about exposure to electromagnetic fields (EMF) from wind turbines, and associated electrical transmission, has been raised at public meetings and legal proceedings. These fears have not been based on any actual measurements of EMF exposure surrounding existing projects but appear to follow from worries from internet sources and misunderstanding of the science. The study was carried out at the Kingsbridge 1 Wind Farm located near Goderich, Ontario, Canada. Magnetic field measurements were collected in the proximity of 15 Vestas 1.8 MW wind turbines, two substations, various buried and overhead collector and transmission lines, and nearby homes. Data were collected during three operational scenarios to characterize potential EMF exposure: 'high wind' (generating power), 'low wind' (drawing power from the grid, but not generating power) and 'shut off' (neither drawing, nor generating power). Background levels of EMF (0.2 to 0.3 mG) were established by measuring magnetic fields around the wind turbines under the 'shut off' scenario. Magnetic field levels detected at the base of the turbines under both the 'high wind' and 'low wind' conditions were low (mean = 0.9 mG; n = 11) and rapidly diminished with distance, becoming indistinguishable from background within 2 m of the base. Magnetic fields measured 1 m above buried collector lines were also within background (≤ 0.3 mG). Beneath overhead 27.5 kV and 500 kV transmission lines, magnetic field levels of up to 16.5 and 46 mG, respectively, were recorded. These levels also diminished rapidly with distance. None of these sources appeared to influence magnetic field levels at nearby homes located as close as just over 500 m from turbines, where measurements immediately outside of the homes were ≤ 0.4 mG. The results suggest that there is nothing unique to wind farms with respect to EMF exposure; in fact, magnetic field levels in the vicinity of wind turbines were lower than those produced by many common household electrical devices and were well below any existing regulatory guidelines with respect to human health.

Level of intrauterine cocaine exposure and neuropsychological test scores in preadolescence: subtle effects on auditory attention and narrative memory.

PubMed

Beeghly, Marjorie; Rose-Jacobs, Ruth; Martin, Brett M; Cabral, Howard J; Heeren, Timothy C; Frank, Deborah A

2014-01-01

Neuropsychological processes such as attention and memory contribute to children's higher-level cognitive and language functioning and predict academic achievement. The goal of this analysis was to evaluate whether level of intrauterine cocaine exposure (IUCE) alters multiple aspects of preadolescents' neuropsychological functioning assessed using a single age-referenced instrument, the NEPSY: A Developmental Neuropsychological Assessment (NEPSY) (Korkman et al., 1998), after controlling for relevant covariates. Participants included 137 term 9.5-year-old children from low-income urban backgrounds (51% male, 90% African American/Caribbean) from an ongoing prospective longitudinal study. Level of IUCE was assessed in the newborn period using infant meconium and maternal report. 52% of the children had IUCE (65% with lighter IUCE, and 35% with heavier IUCE), and 48% were unexposed. Infants with Fetal Alcohol Syndrome, HIV seropositivity, or intrauterine exposure to illicit substances other than cocaine and marijuana were excluded. At the 9.5-year follow-up visit, trained examiners masked to IUCE and background variables evaluated children's neuropsychological functioning using the NEPSY. The association between level of IUCE and NEPSY outcomes was evaluated in a series of linear regressions controlling for intrauterine exposure to other substances and relevant child, caregiver, and demographic variables. Results indicated that level of IUCE was associated with lower scores on the Auditory Attention and Narrative Memory tasks, both of which require auditory information processing and sustained attention for successful performance. However, results did not follow the expected ordinal, dose-dependent pattern. Children's neuropsychological test scores were also altered by a variety of other biological and psychosocial factors. Copyright © 2014 Elsevier Inc. All rights reserved.

Neutrinoless double beta decay in Gerda

NASA Astrophysics Data System (ADS)

Grabmayr, Peter; Gerda Collaboration

2015-10-01

The Germanium Detector Array (Gerda) experiment searches for the neutrinoless double beta decay in 76Ge. This lepton number violating process is predicted by extensions of the standard model. Gerda follows a staged approach by increasing mass and lowering the background level from phase to phase. Gerda is setup at the Gran Sasso underground laboratory of INFN, Italy. An array of high-purity germanium detectors is lowered directly in liquid argon for shielding and cooling. Further background reduction is achieved by an instrumented water buffer. In Phase I an exposure of 21.6 kg yr was collected at a background level of 10-2 cts/(keV kg yr). The lower limit on the half-life of 76Ge > 2 . 1 .1025 yr (90% C.L.) has been published. Further analyses search for decay into excited states or the accompanied Majoron decay. Presently, Phase II is in preparation which intends to reach a background level of 10-3 cts/(keV kg yr) and to increase the exposure to 100 kg yr. About 20 kg of novel thick-window BEGe (Broad Energy Germanium) detectors will be added and the liquid argon will be instrumented. The status of Phase II preparation and results from the commissioning runs will be presented as well as some further results from Phase I.

Relation between residential magnetic fields, light-at-night, and nocturnal urine melatonin levels in women: Volume 1 -- Background and purpose, methods, results, discussion. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaune, W.; Davis, S.; Stevens, R.

Scientists have postulated a link between exposure to magnetic fields and reduced blood melatonin levels. This EPRI study was designed to supplement a National Cancer Institute study (NCI-BC) of magnetic fields, light-at-night, and the risk of breast cancer. By expanding the exposure assessment of the NCI-BC and collecting data on urine melatonin levels, this project provides new insight into a possible magnetic field-melatonin link. It has been proposed that exposure to 60-Hz (power frequency) magnetic fields may increase the risk of breast cancer by suppressing the normal nocturnal rise in melatonin production in the pineal gland. It remains unknown whethermore » the human pineal gland is reproducibly responsive or sensitive to magnetic field exposure, and whether such exposures could alter elements of the endogenous hormonal environment in women that might be important in the etiology of breast cancer. The objective of this research was to investigate whether exposure to power-frequency magnetic fields and/or light-at-night is associated with levels of the primary urinary melatonin metabolite in women without a history of breast cancer.« less

Using Lymphocyte and Plasma Hsp70 as Biomarkers for Assessing Coke Oven Exposure among Steel Workers

PubMed Central

Yang, Xiaobo; Zheng, Jinping; Bai, Yun; Tian, Fengjie; Yuan, Jing; Sun, Jianya; Liang, Huashan; Guo, Liang; Tan, Hao; Chen, Weihong; Tanguay, Robert M.; Wu, Tangchun

2007-01-01

Background Hsp70, an early-response protein induced when organisms are confronted with simple or complicated environmental stresses, can act as either a cellular protector or a danger signal. Objectives The goal of this study was to evaluate levels of lymphocyte and/or plasma Hsp70 as biomarkers for assessing exposure response to complex coke oven emissions (COEs). Methods We recruited 101 coke oven workers and determined levels of polycyclic aromatic hydrocarbon (PAH) exposure, urinary 1-hydroxypyrene (1-OHP), genotoxic damage by comet assay and micronuclei test, and other markers of damage, including plasma malondialdehyde (MDA) and lactate dehydrogenase (LDH). These were compared to levels of lymphocyte (intra-cellular) and plasma (extracellular) Hsp70 using Western blots and enzyme-linked immunosorbent assays (ELISA), respectively. Results We observed a COEs-related dose-dependent increase in levels of DNA damage, micronuclei rate, MDA concentration, and LDH activity. Lymphocyte Hsp70 levels increased in the intermediate-exposure group (1.39 ± 0.88) but decreased in the high-exposure group (1.10 ± 0.55), compared with the low-exposure group. In contrast, plasma Hsp70 levels progressively increased as the dose of exposure increased. Negative correlations were seen between lymphocyte Hsp70 levels and olive tail moment and LDH activity in the intermediate- and high-exposure groups. However, we observed positive correlations between plasma Hsp70 levels and LDH activity in the low and intermediate groups. Conclusions In workers exposed to COEs, high lymphocyte Hsp70 levels may provide protection and high plasma Hsp70 levels may serve as a danger marker. Larger validation studies are needed to establish the utility of Hsp70 as a response marker. PMID:18007987

Weight-of-evidence analysis of human exposures to dioxins and dioxin-like compounds and associations with thyroid hormone levels during early development.

PubMed

Goodman, Julie E; Kerper, Laura E; Boyce, Catherine Petito; Prueitt, Robyn L; Rhomberg, Lorenz R

2010-10-01

Thyroid hormones play a critical role in the proper development of brain function and cell growth. Several epidemiological studies have been conducted to assess potential associations between pre- and post-natal exposure to dioxins or dioxin-like compounds (DLCs) and the levels of circulating thyroid hormones during early development. Dioxins and DLCs include chlorinated dibenzo-p-dioxins, chlorinated dibenzofurans, and mono- and non-ortho polychlorinated biphenyls (PCBs). We identified a total of 23 relevant epidemiological studies (21 cohort studies and 1 case-control study) that measured exposures to various types of dioxins and DLCs as well as markers of thyroid function, such as thyroid stimulating hormone (TSH), total thyroxine (T4), free T4, total triiodothyroxine (T3), free T3, and thyroid-binding globulin concentrations in cord blood or circulation. While some of the studies reported associations between concentrations of dioxins and/or DLCs and some biomarkers of thyroid function, the majority of the observed associations were not statistically significant. Moreover, there were no clear and consistent effects across studies for any of the hormone levels examined, and while a number of studies showed a statistically significant association with exposure for a given marker of thyroid function, other studies showed either no change or changes in the opposite direction for the same thyroid function marker. Similarly, when the results were analyzed considering developmental stage, there generally were no clear and consistent effects at any age from birth through 12 years of age. The absence of a clear correlation between background exposures to dioxins and DLCs and thyroid function biomarkers during development is not consistent with the hypothesis that background exposures to these chemicals cause effects on thyroid function during development. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Metals uptake and health risks associated with cattle grazing on mine tailings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsuji, J.S.

1994-12-31

Cattle are used at a site in Arizona to revegetate mine tailings dams by dispersing seeds and adding fertilizer with their manure. Although this program has been successful in revegetating the slopes, the residual metals in the tailings may potentially be accumulated by the cattle. Using US EPA guidelines on indirect exposure pathways and data on metals in tailings and in grasses, exposure and tissue levels of metals were calculated to assess health threats to the cattle or to those consuming the beef. Lead in the tailings and cadmium in tailings and grasses were selected for detailed exposure analysis viamore » ingestion of tailings and grasses by grazing cattle. Predicted exposures to cattle were below levels resulting in toxic effects to livestock. Estimated human exposures were below the EPA reference dose for cadmium even for a 15 kg child consuming beef or beef liver. Similarly, estimated tissue levels of lead were within reported background dietary levels of lead in beef and kidney. Necropsies of four newborn calves found no evidence of metal toxicity, but possible copper and selenium deficiencies combined with viral infection. Similarly, blood samples from pregnant cattle had non-detectable levels of lead, arsenic, and cadmium.« less

Saliva Cortisol and Exposure to Aircraft Noise in Six European Countries

PubMed Central

Selander, Jenny; Bluhm, Gösta; Theorell, Töres; Pershagen, Göran; Babisch, Wolfgang; Seiffert, Ingeburg; Houthuijs, Danny; Breugelmans, Oscar; Vigna-Taglianti, Federica; Antoniotti, Maria Chiara; Velonakis, Emmanuel; Davou, Elli; Dudley, Marie-Louise; Järup, Lars

2009-01-01

Background Several studies show an association between exposure to aircraft or road traffic noise and cardiovascular effects, which may be mediated by a noise-induced release of stress hormones. Objective Our objective was to assess saliva cortisol concentration in relation to exposure to aircraft noise. Method A multicenter cross-sectional study, HYENA (Hypertension and Exposure to Noise near Airports), comprising 4,861 persons was carried out in six European countries. In a subgroup of 439 study participants, selected to enhance the contrast in exposure to aircraft noise, saliva cortisol was assessed three times (morning, lunch, and evening) during 1 day. Results We observed an elevation of 6.07 nmol/L [95% confidence interval (CI), 2.32–9.81 nmol/L] in morning saliva cortisol level in women exposed to aircraft noise at an average 24-hr sound level (LAeq,24h) > 60 dB, compared with women exposed to LAeq,24h ≤ 50 dB, corresponding to an increase of 34%. Employment status appeared to modify the response. We found no association between noise exposure and saliva cortisol levels in men. Conclusions Our results suggest that exposure to aircraft noise increases morning saliva cortisol levels in women, which could be of relevance for noise-related cardiovascular effects. PMID:20049122

Influence of Low-Level Prenatal Exposure to PCDD/Fs and PCBs on Empathizing, Systemizing and Autistic Traits: Results from the Duisburg Birth Cohort Study

PubMed Central

Nowack, Nikola; Wittsiepe, Jürgen; Kasper-Sonnenberg, Monika; Wilhelm, Michael; Schölmerich, Axel

2015-01-01

Background Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are assumed to act as endocrine disruptor chemicals. Prenatal exposure to these pollutants might influence fetal steroid hormone levels, which are thought to be related to sex-typical development and autistic traits. Objectives We examined associations of prenatal levels of PCDD/Fs and PCBs with autism traits and sex-typical behaviour in childhood. Methods We measured levels of PCDD/Fs and PCBs in maternal blood samples during pregnancy using gas chromatography/high-resolution mass spectrometry. Sex-typical behaviour was assessed at 9 years of age (n = 96) and autistic traits at 10 years of age using the Social Responsiveness Scale (SRS; n = 100). Multiple regression analyses were conducted to estimate the associations between prenatal exposure and outcome variables. Results Blood concentrations (WHO2005-TEq) of ƩPCDD/Fs ranged from 2.93–46.45 pg/g lipid base (median = 12.91 pg/g lipid base) and concentrations of ƩPCBs were in the range of 1.24–25.47 pg/g lipid base (median = 6.85 pg/g lipid base) which is within the range of German background exposure. We found significant negative associations between PCDD/F levels in maternal blood and SRS scores in the whole group (β = -6.66, p < .05), in girls (β = -10.98, p < .05) and, in one SRS subscale, in boys (β = -6.86, p < .05). For PCB levels, associations with one SRS subscale were significant for the whole study group as were associations with two subscales in girls. We did not find significant associations between PCDD/F or PCB levels and sex-typical behaviour for either sex. Conclusions In an earlier part of this study, prenatal exposure to PCDD/Fs and PCBs was found to be associated with lower testosterone levels, therefore, our findings are consistent with the idea that autism spectrum conditions are related to fetal androgen levels. Several possible mechanisms, through which PCDD/Fs and PCBs might influence autistic behaviour, are discussed. PMID:26066795

Effects of noise levels and call types on the source levels of killer whale calls.

PubMed

Holt, Marla M; Noren, Dawn P; Emmons, Candice K

2011-11-01

Accurate parameter estimates relevant to the vocal behavior of marine mammals are needed to assess potential effects of anthropogenic sound exposure including how masking noise reduces the active space of sounds used for communication. Information about how these animals modify their vocal behavior in response to noise exposure is also needed for such assessment. Prior studies have reported variations in the source levels of killer whale sounds, and a more recent study reported that killer whales compensate for vessel masking noise by increasing their call amplitude. The objectives of the current study were to investigate the source levels of a variety of call types in southern resident killer whales while also considering background noise level as a likely factor related to call source level variability. The source levels of 763 discrete calls along with corresponding background noise were measured over three summer field seasons in the waters surrounding the San Juan Islands, WA. Both noise level and call type were significant factors on call source levels (1-40 kHz band, range of 135.0-175.7 dB(rms) re 1 [micro sign]Pa at 1 m). These factors should be considered in models that predict how anthropogenic masking noise reduces vocal communication space in marine mammals.

Health assessment of future PM2.5 exposures from indoor, outdoor, and secondhand tobacco smoke concentrations under alternative policy pathways in Ulaanbaatar, Mongolia

PubMed Central

Edwards, Rufus; Turner, Jay R.; Argo, Yuma D.; Olkhanud, Purevdorj B.; Odsuren, Munkhtuul; Guttikunda, Sarath; Ochir, Chimedsuren; Smith, Kirk R.

2017-01-01

Introduction Winter air pollution in Ulaanbaatar, Mongolia is among the worst in the world. The health impacts of policy decisions affecting air pollution exposures in Ulaanbaatar were modeled and evaluated under business as usual and two more-strict alternative emissions pathways through 2024. Previous studies have relied on either outdoor or indoor concentrations to assesses the health risks of air pollution, but the burden is really a function of total exposure. This study combined projections of indoor and outdoor concentrations of PM2.5 with population time-activity estimates to develop trajectories of total age-specific PM2.5 exposure for the Ulaanbaatar population. Indoor PM2.5 contributions from secondhand tobacco smoke (SHS) were estimated in order to fill out total exposures, and changes in population and background disease were modeled. The health impacts were derived using integrated exposure-response curves from the Global Burden of Disease Study. Results Annual average population-weighted PM2.5 exposures at baseline (2014) were estimated at 59 μg/m3. These were dominated by exposures occurring indoors, influenced considerably by infiltrated outdoor pollution. Under current control policies, exposures increased slightly to 60 μg/m3 by 2024; under moderate emissions reductions and under a switch to clean technologies, exposures were reduced from baseline levels by 45% and 80%, respectively. The moderate improvement pathway decreased per capita annual disability-adjusted life year (DALY) and death burdens by approximately 40%. A switch to clean fuels decreased per capita annual DALY and death burdens by about 85% by 2024 with the relative SHS contribution increasing substantially. Conclusion This study demonstrates a way to combine estimated changes in total exposure, background disease and population levels, and exposure-response functions to project the health impacts of alternative policy pathways. The resulting burden analysis highlights the need for aggressive action, including the elimination of residential coal burning and the reduction of current smoking rates. PMID:29088256

Differences in Blood Pressure and Vascular Responses Associated with Ambient Fine Particulate Matter Exposures Measured at the Personal Versus Community Level

EPA Science Inventory

Background Higher ambient fine particulate matter (PM_2.5) levels can be associated with increased blood pressure and vascular dysfunction. Objectives To determine the differential effects on blood pressure and vascular function of daily changes in community ambient-...

Increased visual sensitivity following periods of dim illumination.

PubMed

McKeown, Alex S; Kraft, Timothy W; Loop, Michael S

2015-02-19

We measured changes in the sensitivity of the human rod pathway by testing visual reaction times before and after light adaptation. We targeted a specific range of conditioning light intensities to see if a physiological adaptation recently discovered in mouse rods is observable at the perceptual level in humans. We also measured the noise spectrum of single mouse rods due to the importance of the signal-to-noise ratio in rod to rod bipolar cell signal transfer. Using the well-defined relationship between stimulus intensity and reaction time (Piéron's law), we measured the reaction times of eight human subjects (ages 24-66) to scotopic test flashes of a single intensity before and after the presentation of a 3-minute background. We also made recordings from single mouse rods and processed the cellular noise spectrum before and after similar conditioning exposures. Subject reaction times to a fixed-strength stimulus were fastest 5 seconds after conditioning background exposure (79% ± 1% of the preconditioning mean, in darkness) and were significantly faster for the first 12 seconds after background exposure (P < 0.01). During the period of increased rod sensitivity, the continuous noise spectrum of individual mouse rods was not significantly increased. A decrease in human reaction times to a dim flash after conditioning background exposure may originate in rod photoreceptors through a transient increase in the sensitivity of the phototransduction cascade. There is no accompanying increase in rod cellular noise, allowing for reliable transmission of larger rod signals after conditioning exposures and the observed increase in perceptual sensitivity. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

ProUCL Version 4.0 Technical Guide

EPA Science Inventory

Statistical inference, including both estimation and hypotheses testing approaches, is routinely used to: estimate environmental parameters of interest, such as exposure point concentration (EPC) terms, not-to-exceed values, and background level threshold values (BTVs) for contam...

Workplace Secondhand Smoke Exposure in the U.S. Trucking Industry

PubMed Central

Chiu, Yueh-Hsiu; Hart, Jaime E.; Spiegelman, Donna; Garshick, Eric; Smith, Thomas J.; Dockery, Douglas W.; Hammond, S. Katharine; Laden, Francine

2010-01-01

Background Although the smoking rate in the United States is declining because of an increase of smoke-free laws, among blue-collar workers it remains higher than that among many other occupational groups. Objectives We evaluated the factors influencing workplace secondhand smoke (SHS) exposures in the U.S. unionized trucking industry. Methods From 2003 through 2005, we measured workplace SHS exposure among 203 nonsmoking and 61 smoking workers in 25 trucking terminals. Workers in several job groups wore personal vapor-phase nicotine samplers on their lapels for two consecutive work shifts and completed a workplace SHS exposure questionnaire at the end of the personal sampling. Results Median nicotine level was 0.87 μg/m3 for nonsmokers and 5.96 μg/m3 for smokers. As expected, smokers experienced higher SHS exposure duration and intensity than did nonsmokers. For nonsmokers, multiple regression analyses indicated that self-reported exposure duration combined with intensity, lack of a smoking policy as reported by workers, having a nondriver job, and lower educational level were independently associated with elevated personal nicotine levels (model R2 = 0.52). Nondriver job and amount of active smoking were associated with elevated personal nicotine level in smokers, but self-reported exposure, lack of a smoking policy, and lower educational level were not. Conclusions Despite movements toward smoke-free laws, this population of blue-collar workers was still exposed to workplace SHS as recently as 2005. The perceived (reported by the workers), rather than the official (reported by the terminal managers), smoking policy was associated with measured SHS exposure levels among the nonsmokers. Job duties and educational level might also be important predictors of workplace SHS exposure. PMID:20123606

Migration of silver from commercial plastic food containers and implications for consumer exposure assessment.

PubMed

von Goetz, Natalie; Fabricius, Lars; Glaus, Reto; Weitbrecht, Volker; Günther, Detlef; Hungerbühler, Konrad

2013-01-01

Food storage containers with embedded silver as an antibacterial agent promise longer durability of food. For risk assessment the release of this silver into the stored food and resulting human exposure need to be known. For the purpose of exposure assessment, silver migration from commercial plastic containers with declared content of 'nano-' or 'micro-silver' into different food simulants (water, 10% ethanol, 3% acetic acid, olive oil) was quantitatively determined by ICP-MS and the form of the released silver was investigated. The highest migration of silver was observed for the acidic food simulant with 30 ng silver cm(-2) contact surface within 10 days at 20°C. In a second and third use cycle, migration dropped by a factor of up to 10, so that the maximum cumulated release over three use cycles was 34 ng cm(-2). The silver release over time was described using a power function and a numerical model that simulates Fickian diffusion through the plastic material. The released silver was found to be in ionic form, but also in the form of silver nanoparticles (around 12%). Consumer exposure to the total amount of silver released from the food containers is low in comparison with the background silver exposure of the general population, but since natural background concentrations are only known for ionic silver, the exposure to silver nanoparticles is not directly comparable with a safe background level.

Perfluoroalkyl acids (PFAAs) and anthropometric measures in the first year of life: Results from the Duisburg Birth Cohort.

PubMed

Alkhalawi, Eman; Kasper-Sonnenberg, Monika; Wilhelm, Michael; Völkel, Wolfgang; Wittsiepe, Jürgen

2016-01-01

In the context of the Duisburg Birth Cohort, this retrospective cohort study provides results of internal exposure to perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and perfluorohexanesulfonic acid (PFHxS) in 156 mother-child pairs, and investigates whether and to what extent in utero exposure of these chemicals at German background levels exerts an effect on newborn and infant weight and length, and weight in relation to length expressed by ponderal index, in order to examine whether any reduction in weight is disproportionate to length. The levels of PFOA, PFOS, and PFHxS were determined in 81 maternal and 83 umbilical cord stored frozen plasma samples and 105 umbilical cord blood samples. Calculated factors were used to convert umbilical cord values to maternal levels. Weights and lengths were retrieved at birth and at 1, 4, 6, and 12 mo from examination booklets and ponderal index (kg/m 3 ) was calculated. Subsequently, correlations were assessed using multiple linear regressions and generalized estimation equations with each of the measures as a continuous outcome variable and with PFOA, PFOS, and PFHxS concentration quartiles as categorized predictor variables, while adjusting for relevant covariates. PFOA, PFOS, and PFHxS were generally within German background exposure levels. There was a significant association between PFOA, PFOS, and PFHxS concentration quartiles and decrease in ponderal index at birth but not weight or height. A nonsignificant negative association between exposure to all three compounds and birth weight was noted. Follow-up showed no sustained effect of the PFAA on anthropometric measures during the first year.

Radiation Safety Issues in High Altitude Commercial Aircraft

NASA Technical Reports Server (NTRS)

Wilson, John W.; Cucinotta, Francis A.; Shinn, Judy L.

1995-01-01

The development of a global economy makes the outlook for high speed commercial intercontinental flight feasible, and the development of various configurations operating from 20 to 30 km have been proposed. In addition to the still unresolved issues relating to current commercial operations (12-16 km), the higher dose rates associated with the higher operating altitudes makes il imperative that the uncertainties in the atmospheric radiation environment and the associated health risks be re-examined. Atmospheric radiation associated with the galactic cosmic rays forms a background level which may, under some circumstances, exceed newly recommended allowable exposure limits proposed on the basis of recent evaluations of the A -bomb survivor data (due to increased risk coefficients). These larger risk coefficients, within the context of the methodology for estimating exposure limits, are resulting in exceedingly low estimated allowable exposure limits which may impact even present day flight operations and was the reason for the CEC workshop in Luxembourg (1990). At higher operating altitudes, solar particles events can produce exposures many orders of magnitude above background levels and pose significant health risks to the most sensitive individuals (such as during pregnancy). In this case the appropriate quality factors are undefined, and some evidence exists which indicates that the quality factor for stochastic effects is a substantial underestimate.

Urinary chromium concentrations in humans following ingestion of safe doses of hexavalent and trivalent chromium: Implications for biomonitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finley, B.L.; Scott, P.K.; Norton, R.L.

1996-08-09

This study evaluates the significance of increased urinary chromium concentrations as a marker of chromium exposure and potential health risk. Six human volunteers ingested trivalent chromium [Cr(III)] and hexavalent chromium [Cr(VI)] at doses that are known to be safe but higher than typical levels. The following dosing regimen was used: d 1-7, 200 {mu}g/d chromium picolinate; d 8-10, Cr(VI) ingestion at the U.S. Environmental Protection Agency (EPA) reference dose (RfD) of 0.005 mg/kg/d; d 11-13, no dose; d 14-16, Cr(III) ingestion at the U.S. EPA RfD of 1.0 mg/kg/d; and 17-18, postdose. Findings are as follows: (1) ingestion of 200more » {mu}g/d of chromium picolinate yielded significantly elevated urine concentrations such that each participant routinely exceeded background, (2) ingestion of the Cr(VI) RfD (0.005 mg/kg/d) yielded individual mean urinary chromium levels (1.2-2.3 {mu}g/L) and a pooled mean urinary chromium level (2.4 {mu}g/L) that significantly exceeded background, and (3) ingestion of the Cr(III) RfD yielded no significantly exceeded background, and (3) ingestion of the Cr(III) RfD yielded no significant increase in urinary chromium concentrations, indicating that little, if any, absorption occurred. Our work identified three critical issues that need to be accounted for in any future studies that will use urinary chromium as a marker of exposure. First, a minimum urinary chromium concentration of approximately 2 {mu}g/L should be used as a screening level to critically identify individuals who may have experienced elevated exposures to chromium. Second, if Cr(III) levels in soils are known to be less than 80,000 ppm and the Cr(III) is insoluble, urinary chromium concentrations are not an appropriate marker of exposure. Third, newer forms of chromium supplements that contain organic forms of Cr(III) must be considered potential confounders and their contribution to residential chromium uptake must be carefully evaluated. 19 refs., 7 figs., 3 tabs.« less

Childhood cancer incidence in relation to sunlight exposure

PubMed Central

Musselman, J R B; Spector, L G

2011-01-01

Background: There is increasing interest in the possible association between cancer incidence and vitamin D through its role as a regulator of cell growth and differentiation. Epidemiological studies in adults and one paediatric study suggest an inverse association between sunlight exposure and cancer incidence. Methods: We carried out an ecological study using childhood cancer registry data and two population-level surrogates of sunlight exposure, (1) latitude of the registry city or population centroid of the registry nation and (2) annual solar radiation. All models were adjusted for nation-level socioeconomic status using socioeconomic indicators. Results: Latitude and radiation were significantly associated with cancer incidence, and the direction of association was consistent between the surrogates. Findings were not consistent across tumour types. Conclusion: Our ecological study offers some evidence to support an association between sunlight exposure and risk of childhood cancer. PMID:21102587

Serum PCBs and organochlorine pesticides in Slovakia: age, gender, and residence as determinants of organochlorine concentrations.

PubMed

Petrik, Jan; Drobna, Beata; Pavuk, Marian; Jursa, Stanislav; Wimmerova, Sona; Chovancova, Jana

2006-10-01

We measured organochlorine concentrations of 15 polychlorinated biphenyl congeners and six organochlorine pesticides (PCB28, 52, 101, 123(+149), 118, 114, 153, 105, 138(+163), 167, 156(+171), 157, 180, 170, 189, alpha-, beta-, gamma-HCH, HCB, p,p'-DDT and p,p'-DDE) in 2047 subjects from contaminated and background areas of eastern Slovakia. Data were collected in 2001 and analyzed by high-resolution gas chromatography with electron capture detection in 2002-2003. Elevated levels persist in subjects from Michalovce district, site of former production facility, after almost 20-years since the end of the PCB manufacturing. Sum of 15 PCB congeners was 3105 ng/g of lipid in the Michalovce district versus 871 ng/g of lipid for subjects from the background districts of Svidnik and Stropkov. Relatively high concentration in children from the Michalovce district, sum PCB = 766 ng/g of lipid versus 372 ng/g of lipid in children from background area suggest ongoing exposure from environmental reservoirs and contaminated food. Consistent differences between genders in both contaminated and background areas are reported here. Levels in males are about 20% higher in both districts. Levels of organochlorine pesticides, particularly of DDT metabolite DDE and hexachlorobenzene are also elevated in the Michalovce district, reflecting intensive use of pesticides in agriculture in the past. About 30% decrease in serum organochlorine levels was observed in comparison with our earlier samples collected in 1998. These results suggest that contamination with PCBs still remains a source of relatively high environmental exposure for subjects in the Michalovce district.

Mortality and emergency hospitalizations associated with atmospheric particulate matter episodes across the UK in spring 2014.

PubMed

Macintyre, Helen L; Heaviside, Clare; Neal, Lucy S; Agnew, Paul; Thornes, John; Vardoulakis, Sotiris

2016-12-01

Exposure to particulate air pollution is known to have negative impacts on human health. Long-term exposure to anthropogenic particulate matter is associated with the equivalent of around 29,000 deaths a year in the UK. However, short-lived air pollution episodes on the order of a few days are also associated with increased daily mortality and emergency hospital admissions for respiratory and cardiovascular conditions. The UK experienced widespread high levels of particulate air pollution in March-April 2014; observations of hourly mean PM 2.5 concentrations reached up to 83μgm -3 at urban background sites. We performed an exposure and health impact assessment of the spring air pollution, focusing on two episodes with the highest concentrations of PM 2.5 (12-14 March and 28 March-3 April 2014). Across these two episodes of elevated air pollution, totalling 10days, around 600 deaths were brought forward from short-term exposure to PM 2.5 , representing 3.9% of total all-cause (excluding external) mortality during these days. Using observed levels of PM 2.5 from other years, we estimate that this is 2.0 to 2.7 times the mortality burden associated with typical urban background levels of PM 2.5 at this time of year. Our results highlight the potential public health impacts and may aid planning for health care resources when such an episode is forecast. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

A Framework for Widespread Replication of a Highly Spatially Resolved Childhood Lead Exposure Risk Model

PubMed Central

Kim, Dohyeong; Galeano, M. Alicia Overstreet; Hull, Andrew; Miranda, Marie Lynn

2008-01-01

Background Preventive approaches to childhood lead poisoning are critical for addressing this longstanding environmental health concern. Moreover, increasing evidence of cognitive effects of blood lead levels < 10 μg/dL highlights the need for improved exposure prevention interventions. Objectives Geographic information system–based childhood lead exposure risk models, especially if executed at highly resolved spatial scales, can help identify children most at risk of lead exposure, as well as prioritize and direct housing and health-protective intervention programs. However, developing highly resolved spatial data requires labor-and time-intensive geocoding and analytical processes. In this study we evaluated the benefit of increased effort spent geocoding in terms of improved performance of lead exposure risk models. Methods We constructed three childhood lead exposure risk models based on established methods but using different levels of geocoded data from blood lead surveillance, county tax assessors, and the 2000 U.S. Census for 18 counties in North Carolina. We used the results to predict lead exposure risk levels mapped at the individual tax parcel unit. Results The models performed well enough to identify high-risk areas for targeted intervention, even with a relatively low level of effort on geocoding. Conclusions This study demonstrates the feasibility of widespread replication of highly spatially resolved childhood lead exposure risk models. The models guide resource-constrained local health and housing departments and community-based organizations on how best to expend their efforts in preventing and mitigating lead exposure risk in their communities. PMID:19079729

Influence of gestation, regular bleeding and intermittent exposure on blood perfluorooctane sulfonate levels in mice: potential factors inducing sex difference and affecting exposure evaluation.

PubMed

Liu, Wei; Li, Xiao; Xu, Lei; Liu, Li; Jin, Yihe; Sato, Itaru; Tsuda, Shuji

2010-06-01

Higher blood levels of perfluorooctane sulfonate (PFOS) in males than the females have been observed in many human biomonitoring studies, which is not well explained yet. The effects of gestation and regular bleeding on blood PFOS level in mice were investigated to evaluate the potential factors that could result in the sex difference. The mice were exposed to PFOS via drinking water at a concentration of 50 mug/l. After 6 weeks of pre-exposure and the gestation period, the blood PFOS concentrations in the gestagenic mice were significantly lower than the control non-gestagenic mice with a ratio of 0.45. Significant lower blood PFOS concentrations in the male mice treated by regular artificial bleeding were observed compared with those from the control male. However, such difference was not observed for the females. The sex difference in the effect of regular artificial bleeding on the blood PFOS level may be caused by the different accumulation and elimination rate in the female and male mice. In addition, the effect of intermittent exposure to PFOS on blood level was evaluated. Each single exposure caused a significant increase in blood PFOS level in both females and males, suggesting the acute exposure to PFOS occurred before the blood sampling, e.g. exposure to PFOS-contaminated foods or drinks, would affect the biomonitoring data to some extent depending on the background blood level. Thus serial blood monitoring is required to obtain accurate body burden.

Exposure to fluoridated drinking water and dental caries experience in Australian army recruits, 1996.

PubMed

Hopcraft, Matthew Scott; Morgan, Michael Vivian

2003-02-01

The purpose of this study was to investigate a group of young Australian adults to determine their caries experience and measure associations between caries experience and age, gender, socioeconomic status, education level and lifetime exposure to fluoridated water. This was achieved through a cross-sectional study involving Australian Army recruits seen for their initial dental examination on enlistment into the Australian Army. A total of 499 recruits had a clinical examination with the aid of bitewing radiographs and an orthopantomograph (OPG). Sociodemographic and fluoride exposure data were obtained via a questionnaire. This study showed that subjects with a lifetime exposure to fluoridated water reported a 23% lower level of caries experience than subjects with no exposure to fluoridated water, with a greater effect on proximal surfaces compared to smooth and occlusal surfaces. Female subjects had a level of caries experience 25% higher than male subjects, while subjects from the lowest socioeconomic background had a level of caries experience 89% times greater than subjects from the highest socioeconomic group. Although it is not possible to directly establish a causal relationship from a cross-sectional study such as this, the results from this study show a dose-response relationship which suggests that there are benefits of lifetime exposure to fluoridated drinking water through young adulthood.

Allergens and β-Glucans in Dutch Homes and Schools: Characterizing Airborne Levels

PubMed Central

Krop, Esmeralda J. M.; Jacobs, José H.; Sander, Ingrid; Raulf-Heimsoth, Monika; Heederik, Dick J. J.

2014-01-01

Background Indoor air quality has an effect on respiratory health. Children are more vulnerable to a decreased indoor air quality as their lungs are still developing. We measured levels of allergens and β-(1,3)-glucans in 19 school buildings and determined whether measured levels could be reproduced. School levels were compared to those in 169 homes and the effect of building characteristics on both home and school exposure was explored. Methods Electrostatic Dust fall Collectors were placed in school buildings for 8 weeks and in homes for 2 weeks to collect settled airborne dust. Cat, dog, and mouse allergen levels, domestic mite antigen levels and β-(1,3)-glucans were measured in the extracts from the collectors. Results were corrected for sampling duration. Using questionnaire data, relations between measured levels and building and classroom characteristics were explored. Results In schools, exposure levels were highest in classrooms and were influenced by the socioeconomic status of the children, the season measurements were performed, moisture status of the building and pet ownership. Repeated measurements in different seasons and over the years showed significantly different levels. Home exposure was influenced by socioeconomic status, occupancy and pet ownership. Domestic mite antigen was found in higher levels in extracts from homes compared to schools while pet allergen levels were 13 times higher in schools compared to homes without pets. For mouse allergen overall levels of exposure were low but still two times higher in schools compared to homes. Levels of β-(1,3)-glucans were also approximately two times higher in schools than in homes. Conclusion Exposure levels of several allergens and β-(1,3)-glucans in schools differ over time and are higher than in homes. For children, exposure levels measured at school could contribute to their total exposure as especially animal allergen levels can be much higher in schools compared to homes. PMID:24551183

Investigation of the Effect of Occupational Noise Exposure on Blood Pressure and Heart Rate of Steel Industry Workers

PubMed Central

Zamanian, Zahra; Rostami, Reza; Hasanzadeh, Jafar; Hashemi, Hassan

2013-01-01

Background and Objectives. This study aimed to investigate the effect of noise exposure on blood pressure and heart rate of steel industry workers. Materials and Methods. In the present cross-sectional study, 50 workers were selected from a steel company in Fars province, Iran, and exposed to 85, 95, and 105 dB noise levels for 5 minutes. The participants' blood pressure and heart rate were measured using Beurer BC16 pulse meter both before and after the exposure. Results. The study results showed no significant difference in blood pressure and heart rate before and after the exposure. However, the workers' systolic blood pressure had increased compared to before the exposure; of course, the difference was not statistically significant (P > 0.05). Besides, although the subjects' heart rate had reduced in comparison to before the exposure, the difference was not statistically significant (P > 0.05). Conclusion. No significant change was observed in blood pressure and heart rate after acute exposure to 85, 95, and 105 dB noise levels. PMID:23781252

The Impact of Prenatal Organophosphate Pesticide Exposures on Thai Infant Neurodevelopment

PubMed Central

Kongtip, Pornpimol; Techasaensiri, Benyachalee; Nankongnab, Noppanun; Adams, Jane; Phamonphon, Akkarat; Surach, Anu; Sangprasert, Supha; Thongsuksai, Aree; Srikumpol, Prayoon; Woskie, Susan

2017-01-01

A birth cohort was begun to investigate the levels and sources of pesticide exposure in pregnant women living in Thailand, and to examine the effects of pesticide exposure on infant neurodevelopment at five months of age. Subjects were interviewed using questionnaires regarding their demographic characteristics, educational background, and work and home activities related to pesticide exposures. Spot urine samples were collected at 28 weeks gestation and analyzed by gas chromatography-mass spectrometry to determine maternal metabolite levels of organophosphate pesticides including dimethyl phosphate (DMP); total DEP (diethyl phosphate (DEP), diethyl thiophosphate (DETP), and diethyl dithiophosphate (DEDTP), and total DAP (the sum of all metabolite levels). At five months of age, infant development was evaluated using the Bayley Scales of Infant and Toddler Development-III (Bayley-III). Higher total DEP and total DAP metabolite levels from the mother at 28 weeks’ gestation were significantly associated with reduced motor composite scores on the Bayley-III at five months of age. The total DEP levels were also significantly associated with reduced cognitive composite scores. Prenatal concentrations of maternal urinary metabolites were associated with infant cognitive and motor development. The results of several studies now suggest the need for public health intervention to reduce prenatal pesticide exposures from both agricultural and domestic use. PMID:28554999

Prenatal exposure to polychlorinated biphenyls and their hydroxylated metabolites is associated with motor development of three-month-old infants.

PubMed

Berghuis, Sietske A; Soechitram, Shalini D; Hitzert, Marrit M; Sauer, Pieter J J; Bos, Arend F

2013-09-01

Polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants that are potentially toxic to the developing brain. Hydroxylated metabolites of PCBs (OH-PCBs) are suggested to be even more toxic. Little is known about their short-term effects on human health. To determine whether prenatal background exposure to PCBs and OH-PCBs was associated with the motor development of three-month-old infants. Ninety-seven mother-infant pairs participated in this Dutch, observational cohort study. We determined the concentrations of PCBs and OH-PCBs in cord blood samples. When the infants were three months old we evaluated their motor development by assessing the presence and performance of spontaneous movement patterns from video recordings. We calculated a Motor Optimality Score (MOS). The score could range from low (5) to high (28) optimality. We explored the correlations between PCB and OH-PCB levels and MOS. Subsequently, we tested whether the levels differed between infants with a low (<26) or high (≥26) MOS and whether the levels associated with detailed aspects of their motor repertoires. We found several associations between PCB and OH-PCB levels and MOS, including detailed aspects of the early motor development. High 4-OH-PCB-107 levels were associated with a low MOS (P=.013). High PCB-187 levels were associated with reduced midline arm and leg movements (P=.047 and P=.043, respectively). High 4'-OH-PCB-172 levels were associated with more manipulation (P=.033). Prenatal exposure to high background levels of most PCBs and 4-OH-PCB-107 seems to impair early motor development, whereas only 4'-OH-PCB-172 showed the opposite. Copyright © 2013 Elsevier Inc. All rights reserved.

Assessment of dietary exposure to bisphenol A in the French population with a special focus on risk characterisation for pregnant French women.

PubMed

Bemrah, Nawel; Jean, Julien; Rivière, Gilles; Sanaa, Moez; Leconte, Stéphane; Bachelot, Morgane; Deceuninck, Yoann; Bizec, Bruno Le; Dauchy, Xavier; Roudot, Alain-Claude; Camel, Valérie; Grob, Konrad; Feidt, Cyril; Picard-Hagen, Nicole; Badot, Pierre-Marie; Foures, Franck; Leblanc, Jean-Charles

2014-10-01

Bisphenol A (BPA) is used in a wide variety of products and objects for consumers use (digital media such as CD's and DVD's, sport equipment, food and beverage containers, medical equipment). Here, we demonstrate the ubiquitous presence of this contaminant in foods with a background level of contamination of less than 5 μg/kg in 85% of the 1498 analysed samples. High levels of contamination (up to 400 μg/kg) were found in some foods of animal origin. We used a probabilistic approach to calculate dietary exposure from French individual consumption data for infants under 36 months, children and adolescents from 3 to 17 years, adults over 18 years and pregnant women. The estimated average dietary exposure ranged from 0.12 to 0.14 μg/kg body weight per day (bw/d) for infants, from 0.05 to 0.06 μg/kg bw/d for children and adolescents, from 0.038 to 0.040 μg/kg bw/d for adults and from 0.05 to 0.06 μg/kg bw/d for pregnant women. The main sources of exposure were canned foods (50% of the total exposure), products of animal origin (20%) and 30% as a background level. Based on the toxicological values set by the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) for pregnant women, the risk was non negligible. Thus, we simulated scenarios to study the influence of cans and/or food of animal origin on the BPA-related risk for this specific population. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biomarker monitoring of controlled dietary acrylamide exposure indicates consistent human endogenous background.

PubMed

Goempel, Katharina; Tedsen, Laura; Ruenz, Meike; Bakuradze, Tamara; Schipp, Dorothea; Galan, Jens; Eisenbrand, Gerhard; Richling, Elke

2017-11-01

The aim of the present study was to explore the relation of controlled dietary acrylamide (AA) intake with the excretion of AA-related urinary mercapturic acids (MA), N-acetyl-S-(carbamoylethyl)-L-cysteine (AAMA) and N-acetyl-S-(1-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA). Excretion kinetics of these short-term exposure biomarkers were monitored under strictly controlled conditions within a duplicate diet human intervention study. One study arm (group A, n = 6) ingested AA via coffee (0.15-0.17 µg/kg bw) on day 6 and in a meal containing an upper exposure level of AA (14.1-15.9 μg/kg bw) on day 10. The other arm (group B) was on AA minimized diet (washout, 0.05-0.06 µg/kg bw) throughout the whole 13-day study period. On day 6, these volunteers ingested 13 C 3 D 3 -AA (1 μg/kg bw). In both arms, urinary MA excretion was continuously monitored and blood samples were taken to determine hemoglobin adducts. Ingestion of four cups of coffee resulted in a slightly enhanced short-term biomarker response within the background range of group B. At the end of the 13-day washout period, group B excreted an AAMA baseline level of 0.14 ± 0.10 µmol/d although AA intake was only about 0.06 µmol/d. This sustained over-proportional AAMA background suggested an endogenous AA baseline exposure level of 0.3-0.4 µg/kg bw/d. The excretion of 13 C 3 D 3 -AA was practically complete within 72-96 h which rules out delayed release of AA (or any other MA precursor) from deep body compartments. The results provide compelling support for the hypothesis of a sustained endogenous AA formation in the human body.

Fluoride exposure and indicators of thyroid functioning in the Canadian population: implications for community water fluoridation

PubMed Central

Barberio, Amanda M; Hosein, F Shaun; Quiñonez, Carlos; McLaren, Lindsay

2017-01-01

Background There are concerns that altered thyroid functioning could be the result of ingesting too much fluoride. Community water fluoridation (CWF) is an important source of fluoride exposure. Our objectives were to examine the association between fluoride exposure and (1) diagnosis of a thyroid condition and (2) indicators of thyroid functioning among a national population-based sample of Canadians. Methods We analysed data from Cycles 2 and 3 of the Canadian Health Measures Survey (CHMS). Logistic regression was used to assess associations between fluoride from urine and tap water samples and the diagnosis of a thyroid condition. Multinomial logistic regression was used to examine the relationship between fluoride exposure and thyroid-stimulating hormone (TSH) level (low/normal/high). Other available variables permitted additional exploratory analyses among the subset of participants for whom we could discern some fluoride exposure from drinking water and/or dental products. Results There was no evidence of a relationship between fluoride exposure (from urine and tap water) and the diagnosis of a thyroid condition. There was no statistically significant association between fluoride exposure and abnormal (low or high) TSH levels relative to normal TSH levels. Rerunning the models with the sample constrained to the subset of participants for whom we could discern some source(s) of fluoride exposure from drinking water and/or dental products revealed no significant associations. Conclusion These analyses suggest that, at the population level, fluoride exposure is not associated with impaired thyroid functioning in a time and place where multiple sources of fluoride exposure, including CWF, exist. PMID:28839078

Workplace exposure to nanoparticles from gas metal arc welding process

NASA Astrophysics Data System (ADS)

Zhang, Meibian; Jian, Le; Bin, Pingfan; Xing, Mingluan; Lou, Jianlin; Cong, Liming; Zou, Hua

2013-11-01

Workplace exposure to nanoparticles from gas metal arc welding (GMAW) process in an automobile manufacturing factory was investigated using a combination of multiple metrics and a comparison with background particles. The number concentration (NC), lung-deposited surface area concentration (SAC), estimated SAC and mass concentration (MC) of nanoparticles produced from the GMAW process were significantly higher than those of background particles before welding ( P < 0.01). A bimodal size distribution by mass for welding particles with two peak values (i.e., 10,000-18,000 and 560-320 nm) and a unimodal size distribution by number with 190.7-nm mode size or 154.9-nm geometric size were observed. Nanoparticles by number comprised 60.7 % of particles, whereas nanoparticles by mass only accounted for 18.2 % of the total particles. The morphology of welding particles was dominated by the formation of chain-like agglomerates of primary particles. The metal composition of these welding particles consisted primarily of Fe, Mn, and Zn. The size distribution, morphology, and elemental compositions of welding particles were significantly different from background particles. Working activities, sampling distances from the source, air velocity, engineering control measures, and background particles in working places had significant influences on concentrations of airborne nanoparticle. In addition, SAC showed a high correlation with NC and a relatively low correlation with MC. These findings indicate that the GMAW process is able to generate significant levels of nanoparticles. It is recommended that a combination of multiple metrics is measured as part of a well-designed sampling strategy for airborne nanoparticles. Key exposure factors, such as particle agglomeration/aggregation, background particles, working activities, temporal and spatial distributions of the particles, air velocity, engineering control measures, should be investigated when measuring workplace exposure to nanoparticles.

Comparative Assessment of Particulate Air Pollution Exposure from Municipal Solid Waste Incinerator Emissions

PubMed Central

Ashworth, Danielle C.; Fuller, Gary W.; Toledano, Mireille B.; Font, Anna; Elliott, Paul; Hansell, Anna L.; de Hoogh, Kees

2013-01-01

Background. Research to date on health effects associated with incineration has found limited evidence of health risks, but many previous studies have been constrained by poor exposure assessment. This paper provides a comparative assessment of atmospheric dispersion modelling and distance from source (a commonly used proxy for exposure) as exposure assessment methods for pollutants released from incinerators. Methods. Distance from source and the atmospheric dispersion model ADMS-Urban were used to characterise ambient exposures to particulates from two municipal solid waste incinerators (MSWIs) in the UK. Additionally an exploration of the sensitivity of the dispersion model simulations to input parameters was performed. Results. The model output indicated extremely low ground level concentrations of PM10, with maximum concentrations of <0.01 μg/m3. Proximity and modelled PM10 concentrations for both MSWIs at postcode level were highly correlated when using continuous measures (Spearman correlation coefficients ~ 0.7) but showed poor agreement for categorical measures (deciles or quintiles, Cohen's kappa coefficients ≤ 0.5). Conclusion. To provide the most appropriate estimate of ambient exposure from MSWIs, it is essential that incinerator characteristics, magnitude of emissions, and surrounding meteorological and topographical conditions are considered. Reducing exposure misclassification is particularly important in environmental epidemiology to aid detection of low-level risks. PMID:23935644

Effects of chronic carbon monoxide exposure on fetal growth and development in mice

PubMed Central

2011-01-01

Background Carbon monoxide (CO) is produced endogenously, and can also be acquired from many exogenous sources: ie. cigarette smoking, automobile exhaust. Although toxic at high levels, low level production or exposure lends to normal physiologic functions: smooth muscle cell relaxation, control of vascular tone, platelet aggregation, anti- inflammatory and anti-apoptotic events. In pregnancy, it is unclear at what level maternal CO exposure becomes toxic to the fetus. In this study, we hypothesized that CO would be embryotoxic, and we sought to determine at what level of chronic CO exposure in pregnancy embryo/fetotoxic effects are observed. Methods Pregnant CD1 mice were exposed to continuous levels of CO (0 to 400 ppm) from conception to gestation day 17. The effect on fetal/placental growth and development, and fetal/maternal CO concentrations were determined. Results Maternal and fetal CO blood concentrations ranged from 1.12- 15.6 percent carboxyhemoglobin (%COHb) and 1.0- 28.6%COHb, respectively. No significant difference was observed in placental histological morphology or in placental mass with any CO exposure. At 400 ppm CO vs. control, decreased litter size and fetal mass (p < 0.05), increased fetal early/late gestational deaths (p < 0.05), and increased CO content in the placenta and the maternal spleen, heart, liver, kidney and lung (p < 0.05) were observed. Conclusions Exposure to levels at or below 300 ppm CO throughout pregnancy has little demonstrable effect on fetal growth and development in the mouse. PMID:22168775

Lifetime Exposure to Intimate Partner Violence and Proinflammatory Cytokine Levels Across the Perinatal Period

PubMed Central

Mittal, Mona; Cai, Xueya; Moynihan, Jan A.; Matthieu, Monica M.; O'Connor, Thomas G.

2016-01-01

Abstract Background: Intimate partner violence (IPV) is a public health concern, affecting one-third of US women. Prior research suggests an association between exposure to IPV and poor maternal perinatal health, but the underlying biological correlates are not well understood. This study examined the relationship between exposure to IPV and proinflammatory cytokine levels, a candidate mechanism accounting for poor psychiatric and obstetric outcomes, across the perinatal period. Materials and Methods: Data were obtained from a prospective, longitudinal cohort study of 171 women receiving obstetrical care from a hospital-based practice serving a predominantly low-income minority population. Participants completed questionnaires on IPV exposure, psychiatric symptoms, and psychosocial and obstetric factors and provided blood samples at 18 and 32 weeks of gestation and 6 weeks and 6 months postpartum. Serum levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) were assayed via enzyme-linked immunosorbent assay. Results: Thirty-five (20.5%) women reported lifetime exposure to IPV and 7 (4.1%) reported being physically hurt in the preceding 12 months (4 while pregnant). Lifetime exposure to IPV was associated with increased likelihood of experiencing perinatal depression and smoking during pregnancy. Women with a history of IPV had significantly higher levels of TNF-α at 18 weeks (z = −2.29, p < 0.05), but significantly smaller changes in levels of IL-6 (β = −0.36, p = 0.04) across time. Conclusion: Lifetime exposure to IPV was associated with a range of adverse mental health outcomes and may affect proinflammatory cytokine levels in pregnancy. PMID:26744816

Exposure of infants to outdoor and indoor air pollution in low-income urban areas - a case study of Delhi.

PubMed

Saksena, Sumeet; Singh, P B; Prasad, Raj Kumar; Prasad, Rakesh; Malhotra, Preeti; Joshi, Veena; Patil, R S

2003-05-01

Indoor air pollution is potentially a very serious environmental and public health problem in India. In poor communities, with the continuing trend in biofuel combustion coupled with deteriorating housing conditions, the problem will remain for some time to come. While to some extent the problem has been studied in rural areas, there is a dearth of reliable data and knowledge about the situation in urban slum areas. The microenvironmental model was used for assessing daily-integrated exposure of infants and women to respirable suspended particulates (RSP) in two slums of Delhi - one in an area of high outdoor pollution and the other in a less polluted area. The study confirmed that indoor concentrations of RSP during cooking in kerosene-using houses are lesser than that in wood-using houses. However, the exposure due to cooking was not significantly different across the two groups. This was because, perhaps due to socioeconomic reasons, kerosene-using women were found to cook for longer durations, cook inside more often, and that infants in such houses stayed in the kitchen for longer durations. It was observed that indoor background levels during the day and at nighttime can be exceedingly high. We speculate that this may have been due to resuspension of dust, infiltration, unknown sources, or a combination of these factors. The outdoor RSP levels measured just outside the houses (near ambient) were not correlated with indoor background levels and were higher than those reported by the ambient air quality monitoring network at the corresponding stations. More importantly, the outdoor levels measured in this study not only underestimated the daily-integrated exposure, but were also poorly correlated with it.

A METHOD FOR EXPOSING RODENTS TO RESUSPENDED PARTICLES USING WHOLE-BODY PLETHYSMOGRAPHY

EPA Science Inventory

Background: Epidemiological studies have reported increased risks of cardiopulmonary-related hospitalization and death in association with exposure to elevated levels of particulate matter (PM) across a wide range of urban areas. In response to these findings, researchers have c...

Factors associated with self-reported health: implications for screening level community-based health and environmental studies

EPA Science Inventory

BACKGROUND: Advocates for environmental justice, local, state, and national public health officials, exposure scientists, need broad-based heath indices to identify vulnerable communities. Longitudinal studies show that perception of current health status predicts subsequent mort...

49 CFR 227.121 - Recordkeeping.

Code of Federal Regulations, 2010 CFR

2010-10-01

... exposure measurement records for specific locations available to regional or national labor representatives... ceases to do business, it shall transfer to the successor employer all records required to be maintained... measurements of the background sound pressure levels in audiometric test rooms; (vi) The model and serial...

VIOLENT CRIME EXPOSURE CLASSIFICATION AND ADVERSE BIRTH OUTCOMES: A GEOGRAPHICALLY-DEFINED COHORT STUDY

EPA Science Inventory

Background

Area-level socioeconomic disparities have long been associated with adverse pregnancy outcomes. Crime is an important element of the neighborhood environment inadequately investigated in the public health literature. Using geocoded linked birth, crime and cens...

Modeling Particle Exposure in US Trucking Terminals

PubMed Central

Davis, ME; Smith, TJ; Laden, F; Hart, JE; Ryan, LM; Garshick, E

2007-01-01

Multi-tiered sampling approaches are common in environmental and occupational exposure assessment, where exposures for a given individual are often modeled based on simultaneous measurements taken at multiple indoor and outdoor sites. The monitoring data from such studies is hierarchical by design, imposing a complex covariance structure that must be accounted for in order to obtain unbiased estimates of exposure. Statistical methods such as structural equation modeling (SEM) represent a useful alternative to simple linear regression in these cases, providing simultaneous and unbiased predictions of each level of exposure based on a set of covariates specific to the exposure setting. We test the SEM approach using data from a large exposure assessment of diesel and combustion particles in the US trucking industry. The exposure assessment includes data from 36 different trucking terminals across the United States sampled between 2001 and 2005, measuring PM2.5 and its elemental carbon (EC), organic carbon (OC) components, by personal monitoring, and sampling at two indoor work locations and an outdoor “background” location. Using the SEM method, we predict: 1) personal exposures as a function of work related exposure and smoking status; 2) work related exposure as a function of terminal characteristics, indoor ventilation, job location, and background exposure conditions; and 3) background exposure conditions as a function of weather, nearby source pollution, and other regional differences across terminal sites. The primary advantage of SEMs in this setting is the ability to simultaneously predict exposures at each of the sampling locations, while accounting for the complex covariance structure among the measurements and descriptive variables. The statistically significant results and high R2 values observed from the trucking industry application supports the broader use of this approach in exposure assessment modeling. PMID:16856739

Domestic Asbestos Exposure: A Review of Epidemiologic and Exposure Data

PubMed Central

Goswami, Emily; Craven, Valerie; Dahlstrom, David L.; Alexander, Dominik; Mowat, Fionna

2013-01-01

Inhalation of asbestos resulting from living with and handling the clothing of workers directly exposed to asbestos has been established as a possible contributor to disease. This review evaluates epidemiologic studies of asbestos-related disease or conditions (mesothelioma, lung cancer, and pleural and interstitial abnormalities) among domestically exposed individuals and exposure studies that provide either direct exposure measurements or surrogate measures of asbestos exposure. A meta-analysis of studies providing relative risk estimates (n = 12) of mesothelioma was performed, resulting in a summary relative risk estimate (SRRE) of 5.02 (95% confidence interval [CI]: 2.48–10.13). This SRRE pertains to persons domestically exposed via workers involved in occupations with a traditionally high risk of disease from exposure to asbestos (i.e., asbestos product manufacturing workers, insulators, shipyard workers, and asbestos miners). The epidemiologic studies also show an elevated risk of interstitial, but more likely pleural, abnormalities (n = 6), though only half accounted for confounding exposures. The studies are limited with regard to lung cancer (n = 2). Several exposure-related studies describe results from airborne samples collected within the home (n = 3), during laundering of contaminated clothing (n = 1) or in controlled exposure simulations (n = 5) of domestic exposures, the latter of which were generally associated with low-level chrysotile-exposed workers. Lung burden studies (n = 6) were also evaluated as a surrogate of exposure. In general, available results for domestic exposures are lower than the workers’ exposures. Recent simulations of low-level chrysotile-exposed workers indicate asbestos levels commensurate with background concentrations in those exposed domestically. PMID:24185840

Urinary naphthalene and phenanthrene as biomarkers of occupational exposure to polycyclic aromatic hydrocarbons

PubMed Central

Sobus, Jon R.; Waidyanatha, Suramya; McClean, Michael D.; Herrick, Robert F.; Smith, Thomas J.; Garshick, Eric; Laden, Francine; Hart, Jaime E.; Zheng, Yuxin; Rappaport, Stephen M.

2009-01-01

Objectives We investigated the utility of unmetabolized naphthalene (Nap) and phenanthrene (Phe) in urine as surrogates for exposures to mixtures of polycyclic aromatic hydrocarbons (PAHs). Methods Our study included workers exposed to diesel exhausts (low PAH exposure level, n = 39) as well as those exposed to emissions from asphalt (medium PAH exposure level, n = 26) and coke ovens (high PAH exposure level, n = 28). Levels of Nap and Phe were measured in urine from each subject using head space-solid phase microextraction and gas chromatography-mass spectrometry. Published levels of airborne Nap, Phe, and other PAHs in the coke-producing and aluminum industries were also investigated. Results In post-shift urine, the highest estimated geometric mean concentrations of Nap and Phe were observed in coke-oven workers (Nap: 2,490 ng/l; Phe: 975 ng/l), followed by asphalt workers (Nap: 71.5 ng/l; Phe: 54.3 ng/l), and by diesel-exposed workers (Nap: 17.7 ng/l; Phe: 3.60 ng/l). After subtracting logged background levels of Nap and Phe from the logged post-shift levels of these PAHs in urine, the resulting values [referred to as ln(adjNap) and ln(adjPhe), respectively] were significantly correlated in each group of workers (0.71 ≤ Pearson r ≤ 0.89), suggesting a common exposure source in each case. Surprisingly, multiple linear regression analysis of ln(adjNap) on ln(adjPhe) showed no significant effect of the source of exposure (coke ovens, asphalt, and diesel exhaust) and further suggested that the ratio of urinary Nap/Phe (in natural scale) decreased with increasing exposure levels. These results were corroborated with published data for airborne Nap and Phe in the coke-producing and aluminum industries. The published air measurements also indicated that Nap and Phe levels were proportional to the levels of all combined PAHs in those industries. Conclusion Levels of Nap and Phe in urine reflect airborne exposures to these compounds and are promising surrogates for occupational exposures to PAH mixtures. Main Messages Urinary naphthalene and phenanthrene are promising surrogates for occupational exposures to PAHs. Policy Implications Measurement of urinary naphthalene and phenanthrene could simplify the assessment of occupational exposures to PAHs. PMID:19017700

Radioactivity in fossils at the Hagerman Fossil Beds National Monument.

PubMed

Farmer, C Neal; Kathren, Ronald L; Christensen, Craig

2008-08-01

Since 1996, higher than background levels of naturally occurring radioactivity have been documented in both fossil and mineral deposits at Hagerman Fossil Beds National Monument in south-central Idaho. Radioactive fossil sites occur primarily within an elevation zone of 900-1000 m above sea level and are most commonly found associated with ancient river channels filled with sand. Fossils found in clay rich deposits do not exhibit discernable levels of radioactivity. Out of 300 randomly selected fossils, approximately three-fourths exhibit detectable levels of natural radioactivity ranging from 1 to 2 orders of magnitude above ambient background levels when surveyed with a portable hand held Geiger-Muller survey instrument. Mineral deposits in geologic strata also show above ambient background levels of radioactivity. Radiochemical lab analysis has documented the presence of numerous natural radioactive isotopes. It is postulated that ancient groundwater transported radioactive elements through sand bodies containing fossils which precipitated out of solution during the fossilization process. The elevated levels of natural radioactivity in fossils may require special precautions to ensure that exposures to personnel from stored or displayed items are kept as low as reasonably achievable (ALARA).

Respiratory health effects of occupational exposure to charcoal dust in Namibia

PubMed Central

Kgabi, Nnenesi

2016-01-01

Background Charcoal processing activities can increase the risk of adverse respiratory outcomes. Objective To determine dose–response relationships between occupational exposure to charcoal dust, respiratory symptoms and lung function among charcoal-processing workers in Namibia. Methods A cross-sectional study was conducted with 307 workers from charcoal factories in Namibia. All respondents completed interviewer-administered questionnaires. Spirometry was performed, ambient and respirable dust levels were assessed in different work sections. Multiple logistic regression analysis estimated the overall effect of charcoal dust exposure on respiratory outcomes, while linear regression estimated the exposure-related effect on lung function. Workers were stratified according to cumulative dust exposure category. Results Exposure to respirable charcoal dust levels was above occupational exposure limits in most sectors, with packing and weighing having the highest dust exposure levels (median 27.7 mg/m3, range: 0.2–33.0 for the 8-h time-weighted average). The high cumulative dust exposure category was significantly associated with usual cough (OR: 2.1; 95% CI: 1.1–4.0), usual phlegm (OR: 2.1; 95% CI: 1.1–4.1), episodes of phlegm and cough (OR: 2.8; 95% CI: 1.1–6.1), and shortness of breath. A non-statistically significant lower adjusted mean-predicted % FEV1 was observed (98.1% for male and 95.5% for female) among workers with greater exposure. Conclusions Charcoal dust levels exceeded the US OSHA recommended limit of 3.5 mg/m3 for carbon-black-containing material and study participants presented with exposure-related adverse respiratory outcomes in a dose–response manner. Our findings suggest that the Namibian Ministry of Labour introduce stronger enforcement strategies of existing national health and safety regulations within the industry. PMID:27687528

Significance of Cytochrome P450 System Responses and Levels of Bile Fluorescent Aromatic Compounds in Marine Wildlife Following Oil Spills

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Richard F.; Anderson, Jack W.

2005-07-01

The relationships among cytochrome P450 induction in marine wildlife species, levels of fluorescent aromatic compounds (FAC) in their bile, the chemical composition of the inducing compounds, the significance of the exposure pathway, and any resulting injury, as a consequence of exposure to crude oil following a spill, are reviewed. Fish collected after oil spills often show increases in cytochrome P450 system activity, cytochrome P4501A (CYP1A) and bile fluorescent aromatic compounds (FAC), that are correlated with exposure to polycyclic aromatic hydrocarbons (PAH) in the oil. There is also some evidence for increases in bile FAC and induction of cytochrome P450 inmore » marine birds and mammals after oil spills. However, when observed, increases in these exposure indicators are transitory and generally decrease to background levels within one year after the exposure. Laboratory studies have shown induction of cytochrome P450 systems occurs after exposure of fish to crude oil in water, sediment or food. Most of the PAH found in crude oil (dominantly 2- and 3-ring PAH) are not strong inducers of cytochrome P450. Exposure to the 4-ring chrysenes or the photooxidized products of the PAH may account for the cytochrome P450 responses in fish collected from oil-spill sites. The contribution of non-spill background PAH, particularly combustion-derived (pyrogenic) PAH, to bile FAC and cytochrome P450 system responses can be confounding and needs to be considered when evaluating oil spill effects. The ubiquity of pyrogenic PAH makes it important to fully characterize all sources of PAH, including PAH from natural resources, e.g. retene, in oil spill studies. In addition, such parameters as species, sex, age, ambient temperature and season need to be taken into account. While increases in fish bile FAC and cytochrome P450 system responses, can together, be sensitive general indicators of PAH exposure after an oil spill, there is little unequivocal evidence to suggest a linkage to higher order biological effects, e.g. toxicity, lesions, reproductive failure.« less

Use of population exposure frequency distributions to simulate effects of policy interventions on NO2 exposure

NASA Astrophysics Data System (ADS)

Dimitroulopoulou, C.; Ashmore, M. R.; Terry, A. C.

2017-02-01

Health effects of air pollution on individuals depend on their personal exposure, but few modelling tools are available which can predict how the distribution of personal exposures within a city will change in response to policies to reduce emissions both indoors and outdoors. We describe a new probabilistic modelling framework (INDAIR-2/EXPAIR), which provides predictions of the personal exposure frequency distribution (PEFD) across a city to assess the effects of both reduced emissions from home sources and reduced roadside concentrations on population exposure. The model uses a national time activity database, which gives the percentage of each population group in different residential and non-residential micro-environments, and links this, for the home, to predictions of concentrations from a three-compartment model, and for non-residential microenvironments to empirical indoor/outdoor ratios. This paper presents modelled PEFDs for NO2 in the city of Leicester, for children, the elderly, and office workers, comparing results in different seasons and on different days of the week. While the mean NO2 population exposure was close to, or below the urban background concentration, the 95%ile of the PEFD was well above the urban background concentration. The relationship between both mean and 95%ile PEFD and urban background concentrations was strongly influenced by air exchange rate. The 24 h mean PEFD showed relative small differences between the population groups, with both removal of home sources and reductions of roadside concentrations on roads with a high traffic density having similar effects in reducing mean exposure. In contrast, the 1 h maximum of the PEFD was significantly higher for children and the elderly than for office workers, and showed a much greater response to reduced home emissions in these groups. The results demonstrate the importance of understanding the dynamics of NO2 exposure at a population level within different groups, if the benefits of policy interventions are to be accurately assessed.

Combat Exposure Severity as a Moderator of Genetic and Environmental Liability to Posttraumatic Stress Disorder

PubMed Central

Wolf, Erika J.; Mitchell, Karen S.; Koenen, Karestan C.; Miller, Mark W.

2014-01-01

Background Twin studies of veterans and adults suggest that approximately 30–46% of the variance in posttraumatic stress disorder (PTSD) is attributable to genetic factors. The remaining variance is attributable to the non-shared environment, which, by definition, includes combat exposure. This study used a gene by measured environment twin design to examine if the effect of genetic and environmental factors that contribute to the etiology PTSD were dependent on level of combat exposure. Methods The sample was drawn from the Vietnam Era Twin Registry and included 620 male-male twin pairs who served in the U.S. Military in South East Asia during the Vietnam War era. Analyses were based on data from a clinical diagnostic interview of lifetime PTSD symptoms and a self-report measure of combat exposure. Results Biometric modeling revealed that the effect of genetic and non-shared environment factors on PTSD varied as a function of level of combat exposure such that the association between these factors and PTSD was stronger at higher levels of combat exposure. Conclusions Combat exposure may act as a catalyst that augments the impact of hereditary and environmental contributions to PTSD. Individuals with the greatest exposure to combat trauma were at increased risk for PTSD as a function of both genetic and other environmental factors. Additional work is needed to determine the biological and environmental mechanisms driving these associations. PMID:24001428

Acute myeloid and chronic lymphoid leukaemias and exposure to low-level benzene among petroleum workers

PubMed Central

Rushton, L; Schnatter, A R; Tang, G; Glass, D C

2014-01-01

Background: High benzene exposure causes acute myeloid leukaemia (AML). Three petroleum case–control studies identified 60 cases (241 matched controls) for AML and 80 cases (345 matched controls) for chronic lymphoid leukaemia (CLL). Methods: Cases were classified and scored regarding uncertainty by two haematologists using available diagnostic information. Blinded quantitative benzene exposure assessment used work histories and exposure measurements adjusted for era-specific circumstances. Statistical analyses included conditional logistic regression and penalised smoothing splines. Results: Benzene exposures were much lower than previous studies. Categorical analyses showed increased ORs for AML with several exposure metrics, although patterns were unclear; neither continuous exposure metrics nor spline analyses gave increased risks. ORs were highest in terminal workers, particularly for Tanker Drivers. No relationship was found between benzene exposure and risk of CLL, although the Australian study showed increased risks in refinery workers. Conclusion: Overall, this study does not persuasively demonstrate a risk between benzene and AML. A previously reported strong relationship between myelodysplastic syndrome (MDS) (potentially previously reported as AML) at our study's low benzene levels suggests that MDS may be the more relevant health risk for lower exposure. Higher CLL risks in refinery workers may be due to more diverse exposures than benzene alone. PMID:24357793

Correlates of exposure to second-hand smoke in an urban Mediterranean population

PubMed Central

Twose, Jorge; Schiaffino, Anna; García, Montse; Borras, Josep Maria; Fernández, Esteve

2007-01-01

Background To describe the socio-demographic factors associated with exposure to second-hand smoke (SHS) in different settings (home, leisure, and workplace). Methods We analysed cross-sectional data on self-reported SHS exposure in 1059 non-daily smokers interviewed in the Cornellà Health Interview Survey Follow-up Study in 2002. We calculated age-adjusted prevalence rates and prevalence rate ratios of SHS exposure at home, at the workplace, during leisure time, and in any of these settings. Results The age-standardized prevalence rate of SHS exposure in any setting was 69.5% in men and 62.9% in women. Among men, 25.9% reported passive smoking at home, 55.1% during leisure time, and 34.0% at the workplace. Among women, prevalence rates in these settings were 34.1%, 44.3% and 30.1%, respectively. Overall exposure to SHS decreased with age in both men and women. In men, SHS exposure was related to marital status, physical activity, smoking, and alcohol intake. In women, SHS exposure was related to educational level, marital status, occupational status, self-perceived health, smoking-related illness, and alcohol intake. Conclusion The prevalence of SHS exposure in this population was high. The strongest association with exposure were found for age and occupational status in men, and age and educational level in women. PMID:17683585

Energy drink consumption and impact on caffeine risk.

PubMed

Thomson, Barbara M; Campbell, Donald M; Cressey, Peter; Egan, Ursula; Horn, Beverley

2014-01-01

The impact of caffeine from energy drinks occurs against a background exposure from naturally occurring caffeine (coffee, tea, cocoa and foods containing these ingredients) and caffeinated beverages (kola-type soft drinks). Background caffeine exposure, excluding energy drinks, was assessed for six New Zealand population groups aged 15 years and over (n = 4503) by combining concentration data for 53 caffeine-containing foods with consumption information from the 2008/09 New Zealand Adult Nutrition Survey (ANS). Caffeine exposure for those who consumed energy drinks (n = 138) was similarly assessed, with inclusion of energy drinks. Forty-seven energy drink products were identified on the New Zealand market in 2010. Product volumes ranged from 30 to 600 ml per unit, resulting in exposures of 10-300 mg caffeine per retail unit consumed. A small percentage, 3.1%, of New Zealanders reported consuming energy drinks, with most energy drink consumers (110/138) drinking one serving per 24 h. The maximum number of energy drinks consumed per 24 h was 14 (total caffeine of 390 mg). A high degree of brand loyalty was evident. Since only a minor proportion of New Zealanders reported consuming energy drinks, a greater number of New Zealanders exceeded a potentially adverse effect level (AEL) of 3 mg kg(-1) bw day(-1) for caffeine from caffeine-containing foods than from energy drinks. Energy drink consumption is not a risk at a population level because of the low prevalence of consumption. At an individual level, however, teenagers, adults (20-64 years) and females (16-44 years) were more likely to exceed the AEL by consuming energy drinks in combination with caffeine-containing foods.

Perception and reality of particulate matter exposure in New York City taxi drivers

PubMed Central

Gany, Francesca; Bari, Sehrish; Prasad, Lakshmi; Leng, Jennifer; Lee, Trevor; Thurston, George D; Gordon, Terry; Acharya, Sudha; Zelikoff, Judith T

2017-01-01

Background Exposure to fine particulate matter (PM2.5) and black carbon (BC) have been linked to negative health risks, but exposure among professional taxi drivers is unknown. This study measured drivers' knowledge, attitudes, and beliefs (KAB) about air pollution compared to direct measures of exposures. Methods Roadside and in-vehicle levels of PM2.5 and BC were continuously measured over a single shift and compared to central site monitoring. Participants completed an air pollution KAB questionnaire. Results Taxicab PM2.5 and BC concentrations were elevated compared to central monitoring. Average PM2.5 concentrations per 15-minute interval were 4 - 49 μg/m3; 1-minute peaks measured up to 452 μg/m3. BC levels were also elevated; reaching > 10 μg/m3. 56 of 100 drivers surveyed believed they were more exposed than non-drivers; 81 believed air pollution causes health problems. Conclusions Air pollution exposure among drivers likely exceeds EPA recommendations. Future studies should focus on reducing exposures and increasing awareness among taxi drivers. PMID:27168392

HELLE: Health Effects of Low Level Exposures/ Gezondheidseffecten van lage blootstellingniveaus [International workshop: Influence of low level exposures to chemicals and radiation on human and ecological health

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schoten, Eert

1998-11-26

The Health Council is closely involved in establishing the scientific foundation of exposure limits for substances and radiation in order to protect public health. Through the years, the Council has contributed to the formulation of principles and procedures, both for carcinogenic and for noncarcinogenic agents. As a rule, the discussion with regard to the derivation of health-based recommended exposure limits centers around the appropriateness of extrapolation methods (What can be inferred from data on high exposure levels and on experimental animals?). Generally speaking, there is a lack of direct information on the health effects of low levels of exposure. Effectsmore » at these levels cannot usually be detected by means of traditional animal experiments or epidemiological research. The capacity of these analytical instruments to distinguish between ''signal'' and ''noise'' is inadequate in most cases. Annex B of this report contains a brief outline of the difficulties and the established methods for tackling this problem. In spite of this, the hope exists that the posited weak signals, if they are indeed present, can be detected by other means. The search will have to take place on a deeper level. In other words, effort must be made to discover what occurs at underlying levels of biological organization when organisms are exposed to low doses of radiation or substances. Molecular and cell biology provide various methods and techniques which give an insight into the processes within the cell. This results in an increase in the knowledge about the molecular and cellular effects of exposure to agents, or stated differently, the working mechanisms which form the basis of the health effects. Last year, the Health Council considered that the time was ripe to take stock of the state of knowledge in this field. To this end, an international working conference was held from 19 to 21 October 1997, entitled ''Health Effects of Low Level Exposures: Scientific Developments and Perspectives for Risk Assessment''. The central question was the extent to which the sometimes fast-growing knowledge about molecular and cellular effects offers the desired basis for extrapolation. Against this setting, a number of more specific questions which have been hotly debated for some time were also addressed. One of the primary questions concerned the traditional but increasingly questioned division between stochastic and non-stochastic working agents, and the corresponding division between exposure-effect relations without a threshold and with a threshold. Thoughts were also exchanged on what is often referred to as hormesis: the notion that low levels of exposure could actually improve health. For the purpose of illuminating the many aspects of these issues, experts from a number of areas were invited. In addition to this, three agents were selected to serve as points of crystallization for the general debate: ionizing radiation, ultraviolet (UV) radiation and dioxins. The present report calls attention to a selection of issues which emerged during the discussions on the above-mentioned central topic. Various more detailed questions and the wider context of the points considered are described at greater length in the enclosed conference report and in the background documents attached to the report. What follows is a series of considerations regarding the scientific basis for the derivation of recommended exposure levels, viewed in the light of current procedures and against the background of the work of the Health Council. In the preparation of the following comments and recommendations, various Dutch experts have been consulted.« less

The role of genetic background in susceptibility to chemical warfare nerve agents across rodent and non-human primate models.

PubMed

Matson, Liana M; McCarren, Hilary S; Cadieux, C Linn; Cerasoli, Douglas M; McDonough, John H

2018-01-15

Genetics likely play a role in various responses to nerve agent exposure, as genetic background plays an important role in behavioral, neurological, and physiological responses to environmental stimuli. Mouse strains or selected lines can be used to identify susceptibility based on background genetic features to nerve agent exposure. Additional genetic techniques can then be used to identify mechanisms underlying resistance and sensitivity, with the ultimate goal of developing more effective and targeted therapies. Here, we discuss the available literature on strain and selected line differences in cholinesterase activity levels and response to nerve agent-induced toxicity and seizures. We also discuss the available cholinesterase and toxicity literature across different non-human primate species. The available data suggest that robust genetic differences exist in cholinesterase activity, nerve agent-induced toxicity, and chemical-induced seizures. Available cholinesterase data suggest that acetylcholinesterase activity differs across strains, but are limited by the paucity of carboxylesterase data in strains and selected lines. Toxicity and seizures, two outcomes of nerve agent exposure, have not been fully evaluated for genetic differences, and thus further studies are required to understand baseline strain and selected line differences. Published by Elsevier B.V.

Cardiac Teratogenicity in Mouse Maternal Phenylketonuria: Defining phenotype parameters and genetic background influences

PubMed Central

Seagraves, Nikki J.; McBride, Kim L.

2012-01-01

Maternal phenylketonuria (MPKU) is a syndrome including cardiovascular malformations (CVMs), microcephaly, intellectual impairment, and small for gestational age, caused by in-utero exposure to elevated serum phenylalanine (Phe) due to PKU in the mother. It is becoming a public health concern as more women with PKU reach child bearing age. Although a mouse model of PKU, BTBR Pahenu2, has been available for 20 years, it has not been well utilized for studying MPKU. We used this model to delineate critical parameters in Phe cardiovascular teratogenicity and study the effect of genetic background. Dosing and timing experiments were performed with the BTBR Pahenu2 mouse. A dose response curve was noted, with CVM rates at maternal serum Phe levels <360 μM (control), 360 – 600 μM (low), 600 – 900 μM (mid), and >900μM (high) of 11.86%, 16.67%, 30.86%, and 46.67% respectively. A variety of CVMs were noted on the BTBR background, including double outlet right ventricle (DORV), aortic arch artery (AAA)abnormalities, and ventricular septal defects (VSDs). Timed exposure experiments identified a teratogenic window from embryonic day 8.5-13.5, with higher rates of conotruncal and valve defects occurring in early exposure time and persistent truncus arteriosus (PTA) and aortic arch branching abnormalities occurring with late exposure. Compared to the BTBR strain, N10+ Pahenu2 congenics on the C3H/HeJ background had higher rates of CVMs in general and propensity to left ventricular outflow tract (LVOT) malformations, while the C57B/L6 background had similar CVM rates but predominately AAA abnormalities. We have delineated key parameters of Phe cardiovascular teratogenicity, demonstrated the utility of this MPKU model on different mouse strains, and shown how genetic background profoundly affects the phenotype. PMID:22951387

A record-based case-control study of natural background radiation and the incidence of childhood leukaemia and other cancers in Great Britain during 1980-2006.

PubMed

Kendall, G M; Little, M P; Wakeford, R; Bunch, K J; Miles, J C H; Vincent, T J; Meara, J R; Murphy, M F G

2013-01-01

We conducted a large record-based case-control study testing associations between childhood cancer and natural background radiation. Cases (27,447) born and diagnosed in Great Britain during 1980-2006 and matched cancer-free controls (36,793) were from the National Registry of Childhood Tumours. Radiation exposures were estimated for mother's residence at the child's birth from national databases, using the County District mean for gamma rays, and a predictive map based on domestic measurements grouped by geological boundaries for radon. There was 12% excess relative risk (ERR) (95% CI 3, 22; two-sided P=0.01) of childhood leukaemia per millisievert of cumulative red bone marrow dose from gamma radiation; the analogous association for radon was not significant, ERR 3% (95% CI -4, 11; P=0.35). Associations for other childhood cancers were not significant for either exposure. Excess risk was insensitive to adjustment for measures of socio-economic status. The statistically significant leukaemia risk reported in this reasonably powered study (power ~50%) is consistent with high-dose rate predictions. Substantial bias is unlikely, and we cannot identify mechanisms by which confounding might plausibly account for the association, which we regard as likely to be causal. The study supports the extrapolation of high-dose rate risk models to protracted exposures at natural background exposure levels.

Ambient x-ray pollution assessment at inspection gates of airports- a case study of Mehrabad and Imam Khomeini Airports in Iran

PubMed Central

2014-01-01

Background As a well-known, physical carcinogen, ambient X-ray pollution assessment would be of great importance in today’s modern world. Accordingly, the present study was done to measure the exposure level of ambient X-ray at inspection gates of two airports in Iran. According to which, the X-ray was measured at different points of the inspection gates including closed and opened Curtain, as well as seating place of operators beside the X-ray inspection systems. The recorded data were then analyzed by “sign” and t-tests. Results The total average exposure level of the measured x-ray was 2.68 ± 0.73 μsv.h-1. The measured x-ray exposure level was 2.07 ± 0.61 (μsv.h-1) released from RAPISCAN X-ray inspection system and 3.3 ± 1.34 (μsv.h-1) emitted from HEIMANN X-ray inspection system. Comparison of average x-ray doses of the systems in both airports showed that the minimum and maximum exposure levels were recorded at 1(m) far from the devices and at the entrance of the devices, respectively. Conclusions The exposure levels at all measurement points were lower than the occupational exposure limit. This reveals the fact that the exposed operators are not probably at risk of adverse health effects. PMID:24955243

Exposure–Response Analyses of Asbestos and Lung Cancer Subtypes in a Pooled Analysis of Case–Control Studies

PubMed Central

Vermeulen, Roel; Schüz, Joachim; Kromhout, Hans; Pesch, Beate; Peters, Susan; Behrens, Thomas; Portengen, Lützen; Mirabelli, Dario; Gustavsson, Per; Kendzia, Benjamin; Almansa, Josue; Luzon, Veronique; Vlaanderen, Jelle; Stücker, Isabelle; Guida, Florence; Consonni, Dario; Caporaso, Neil; Landi, Maria Teresa; Field, John; Brüske, Irene; Wichmann, Heinz-Erich; Siemiatycki, Jack; Parent, Marie-Elise; Richiardi, Lorenzo; Merletti, Franco; Jöckel, Karl-Heinz; Ahrens, Wolfgang; Pohlabeln, Hermann; Plato, Nils; Tardón, Adonina; Zaridze, David; McLaughlin, John; Demers, Paul; Szeszenia-Dabrowska, Neonila; Lissowska, Jolanta; Rudnai, Peter; Fabianova, Eleonora; Stanescu Dumitru, Rodica; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Boffetta, Paolo; Bueno-de-Mesquita, Bas; Forastiere, Francesco; Brüning, Thomas; Straif, Kurt

2017-01-01

Background: Evidence is limited regarding risk and the shape of the exposure–response curve at low asbestos exposure levels. We estimated the exposure–response for occupational asbestos exposure and assessed the joint effect of asbestos exposure and smoking by sex and lung cancer subtype in general population studies. Methods: We pooled 14 case–control studies conducted in 1985–2010 in Europe and Canada, including 17,705 lung cancer cases and 21,813 controls with detailed information on tobacco habits and lifetime occupations. We developed a quantitative job-exposure-matrix to estimate job-, time period-, and region-specific exposure levels. Fiber-years (ff/ml-years) were calculated for each subject by linking the matrix with individual occupational histories. We fit unconditional logistic regression models to estimate odds ratios (ORs), 95% confidence intervals (CIs), and trends. Results: The fully adjusted OR for ever-exposure to asbestos was 1.24 (95% CI, 1.18, 1.31) in men and 1.12 (95% CI, 0.95, 1.31) in women. In men, increasing lung cancer risk was observed with increasing exposure in all smoking categories and for all three major lung cancer subtypes. In women, lung cancer risk for all subtypes was increased in current smokers (ORs ~two-fold). The joint effect of asbestos exposure and smoking did not deviate from multiplicativity among men, and was more than additive among women. Conclusions: Our results in men showed an excess risk of lung cancer and its subtypes at low cumulative exposure levels, with a steeper exposure–response slope in this exposure range than at higher, previously studied levels. (See video abstract at, http://links.lww.com/EDE/B161.) PMID:28141674

Gestational Diabetes and Preeclampsia in Association with Air Pollution at Levels below Current Air Quality Guidelines

PubMed Central

Jakobsson, Kristina; Tinnerberg, Håkan; Rignell-Hydbom, Anna; Rylander, Lars

2013-01-01

Background: Several studies have estimated associations between air pollution and birth outcomes, but few have evaluated potential effects on pregnancy complications. Objective: We investigated whether low-level exposure to air pollution is associated with gestational diabetes and preeclampsia. Methods: High-quality registry information on 81,110 singleton pregnancy outcomes in southern Sweden during 1999–2005 was linked to individual-level exposure estimates with high spatial resolution. Modeled exposure to nitrogen oxides (NOx), expressed as mean concentrations per trimester, and proximity to roads of different traffic densities were used as proxy indicators of exposure to combustion-related air pollution. The data were analyzed by logistic regression, with and without adjusting for potential confounders. Results: The prevalence of gestational diabetes increased with each NOx quartile, with an adjusted odds ratio (OR) of 1.69 (95% CI: 1.41, 2.03) for the highest (> 22.7 µg/m3) compared with the lowest quartile (2.5–8.9 µg/m3) of exposure during the second trimester. The adjusted OR for acquiring preeclampsia after exposure during the third trimester was 1.51 (1.32, 1.73) in the highest quartile of NOx compared with the lowest. Both outcomes were associated with high traffic density, but ORs were significant for gestational diabetes only. Conclusion: NOx exposure during pregnancy was associated with gestational diabetes and preeclampsia in an area with air pollution levels below current air quality guidelines. PMID:23563048

Social Disparities in Exposure to Point-of-Sale Cigarette Marketing.

PubMed

Siahpush, Mohammad; Farazi, Paraskevi A; Kim, Jungyoon; Michaud, Tzeyu L; Yoder, Aaron M; Soliman, Ghada; Tibbits, Melissa K; Nguyen, Minh N; Shaikh, Raees A

2016-12-21

While most ecological studies have shown that higher levels of point-of-sale (POS) cigarette marketing are associated with larger proportions of residents from lower socioeconomic and minority backgrounds in neighborhoods, there are no studies that examine individual-level social disparities in exposure to POS cigarette marketing among smokers in the United States. Our aim was to examine these disparities in a Midwestern metropolitan area in the United States. We conducted a telephone survey to collect data on 999 smokers. Cigarette marketing was measured by asking respondents three questions about noticing advertisements, promotions, and displays of cigarettes within their respective neighborhoods. The questions were combined to create a summated scale. We estimated ordered logistic regression models to examine the association of sociodemographic variables with exposure to POS cigarette marketing. Adjusted results showed that having a lower income ( p < 0.003) and belonging to a race/ethnicity other than "non-Hispanic White" ( p = 0.011) were associated with higher levels of exposure to POS cigarette marketing. The results highlight social disparities in exposure to POS cigarette marketing in the United States, which can potentially be eliminated by banning all forms of cigarette marketing.

Social Disparities in Exposure to Point-of-Sale Cigarette Marketing

PubMed Central

Siahpush, Mohammad; Farazi, Paraskevi A.; Kim, Jungyoon; Michaud, Tzeyu L.; Yoder, Aaron M.; Soliman, Ghada; Tibbits, Melissa K.; Nguyen, Minh N.; Shaikh, Raees A.

2016-01-01

While most ecological studies have shown that higher levels of point-of-sale (POS) cigarette marketing are associated with larger proportions of residents from lower socioeconomic and minority backgrounds in neighborhoods, there are no studies that examine individual-level social disparities in exposure to POS cigarette marketing among smokers in the United States. Our aim was to examine these disparities in a Midwestern metropolitan area in the United States. We conducted a telephone survey to collect data on 999 smokers. Cigarette marketing was measured by asking respondents three questions about noticing advertisements, promotions, and displays of cigarettes within their respective neighborhoods. The questions were combined to create a summated scale. We estimated ordered logistic regression models to examine the association of sociodemographic variables with exposure to POS cigarette marketing. Adjusted results showed that having a lower income (p < 0.003) and belonging to a race/ethnicity other than “non-Hispanic White” (p = 0.011) were associated with higher levels of exposure to POS cigarette marketing. The results highlight social disparities in exposure to POS cigarette marketing in the United States, which can potentially be eliminated by banning all forms of cigarette marketing. PMID:28009807

A National Study on Nurses’ Exposure to Occupational Violence in Lebanon: Prevalence, Consequences and Associated Factors

PubMed Central

Alameddine, Mohamad; Mourad, Yara; Dimassi, Hani

2015-01-01

Background Healthcare institutions have commonly reported exposure of employees, particularly nurses, to high levels of occupational violence. Despite such evidence in the Middle East Region, there is a dearth of national studies that have systematically investigated this phenomenon. This study investigates the prevalence, characteristics, consequences and factors associated with nurses’ exposure to occupational violence in Lebanon. Methods A cross-sectional design was utilized to survey a nationally representative sample of 915 nurses registered with the Order of Nurses in Lebanon. Stratified random sampling by governorate was utilized. Individually-mailed questionnaires collected information on exposure to violence, degree of burnout and demographic/professional background. The main outcome variables were exposure to verbal abuse (never, 1–3, 4–9 and 10+ times) and physical violence (never, ever) over the past 12-months. Descriptive statistics were used to estimate prevalence of violence. Multivariable, binomial and multinomial regression models were carried out to investigate the correlates of exposure to verbal abuse and physical violence, respectively. Results Response rate was 64.8%. Over the last year, prevalence of nurses’ exposure to verbal abuse was 62%, (CI: 58–65%) and physical violence was 10%, (CI: 8–13%). Among respondents, 31.7% of nurses indicated likelihood to quit their jobs and 22.3% were undetermined. Furthermore, 54.1% reported high levels of emotional exhaustion and 28.8% reported high levels of depersonalization. Compared to nurses with no exposure to verbal abuse, nurses reporting high exposure had high levels of emotional exhaustion (OR:6.4; CI:1.76–23.32), depersonalization (OR:6.8; CI: 3–15) and intention to quit job (OR:3.9; CI: 1.8–8.3). They further reported absence of anti-violence policies at their institutions (OR: 3; CI: 1.5–6.3). Nurses that were ever exposed to physical violence were more likely to be males (OR: 2.2; CI: 1.1–4.3), working day and night shifts (OR: 2.8; CI: 1.4–5.5) and subject to ten or more incidents of verbal abuse per year (OR: 46.7; CI: 10.1–214). Conclusions An alarming two-thirds of respondents reported exposure to verbal abuse which was found to be a significant predictor of the three subscales of burnout, intention to quit and exposure to physical violence. The prevalence of exposure to physical violence is disconcerting due to its severe consequences. Policy and decision-makers are urged to use study findings for policy and practice interventions to create safe work environments conducive to nurses’ productivity and retention. PMID:26355686

A study of the effect of flight density and background noise on V/STOL acceptability. [effective perceived noise level as measure of annoyance

NASA Technical Reports Server (NTRS)

Sternfeld, H., Jr.; Hinterkeuser, E. G.; Hackman, R. B.; Davis, J.

1974-01-01

A study was conducted in which test subjects evaluated the sounds of a helicopter, a turbofan STOL and a turbojet airplane while engaged in work and leisure activities. Exposure to a high repetitive density of the aircraft sounds did not make the individual sounds more annoying but did create an unacceptable environment. The application of a time duration term to db(A) resulted in a measure which compared favorably with EPNL as a predictor of annoyance. Temporal variations in background noise level had no significant effect on the rated annoyance.

Detection of low level benzene exposure in supermarket wrappers by urinary muconic acid.

PubMed

E S Johnson S Halabi G Netto G Lucier W Bechtold R Henderson

1999-01-01

Women who use the 'hot wire' and 'cool rod' machines to wrap meat in supermarkets are potentially exposed to low levels of benzene and polycyclic aromatic hydrocarbons present in fumes emitted during the thermal decomposition of the plastic used to wrap meat. In order to evaluate whether the benzene metabolite trans, trans-muconic acid (MA) can be used to monitor these low levels, we collected urine samples from supermarket workers, and assayed the urine for MA. Geometric mean after-shift MA levels were highest for subjects who used the 'hot wire' machine, i.e. > 300 ng mg-1 creatinine (Cr). The corresponding levels for subjects who used the 'cool rod' machine were similar to those for subjects who did not use either type of machine, and were much lower. These results indicate that urinary muconic acid has some potential for use in monitoring benzene exposures of less than 1 part per million (ppm). The study detected very high background MA levels (exceeding 2000 ng mg-1 Cr) in some subjects, suggesting that individuals in the general population without occupational exposure to benzene may have urinary MA levels equivalent to exposure to up to 2 ppm benzene in ambient air. However, since non-benzene sources of the metabolite cannot be completely ruled out as partially responsible for these high levels, the public health significance of this finding is not known at the moment.

Environmental Enrichment Alters Neurotrophin Levels After Fetal Alcohol Exposure in Rats

PubMed Central

Parks, Elizabeth A.; McMechan, Andrew P.; Hannigan, John H.; Berman, Robert F.

2014-01-01

Background Prenatal alcohol exposure causes abnormal brain development, leading to behavioral deficits, some of which can be ameliorated by environmental enrichment. As both environmental enrichment and prenatal alcohol exposure can individually alter neurotrophin expression, we studied the interaction of prenatal alcohol and postweaning environmental enrichment on brain neurotrophin levels in rats. Methods Pregnant rats received alcohol by gavage, 0, 4, or 6 g / kg / d (Zero, Low, or High groups), or no treatment (Naïve group), on gestational days 8 to 20. After weaning on postnatal day 21, offspring were housed for 6 weeks in Isolated, Social, or Enriched conditions. Levels of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) were then measured in frontal cortex, occipital cortex, hippocampus, and cerebellar vermis. Results Prenatal alcohol exposure increased NGF levels in frontal cortex (High-dose group) and cerebellar vermis (High- and Low-dose groups); increased BDNF in frontal cortex, occipital cortex and hippocampus (Low-dose groups), and increased NT-3 in hippocampus and cerebellar vermis (High-dose). Environmental enrichment resulted in lower NGF, BDNF, and NT-3 levels in occipital cortex and lower NGF in frontal cortex. The only significant interaction between prenatal alcohol treatment and environment was in cerebellar vermis where NT-3 levels were higher for enriched animals after prenatal alcohol exposure, but not for animals housed under Isolated or Social conditions. Conclusions Both prenatal alcohol exposure and postweaning housing conditions alter brain neurotrophin levels, but the effects appear to be largely independent. Although environmental enrichment can improve functional outcomes, these results do not provide strong support for the hypothesis that rearing in a complex environment ameliorates prenatal alcohol effects on brain neurotrophin levels in rats. PMID:18652597

Occupational exposure to diesel engine exhaust: A literature review

PubMed Central

Pronk, Anjoeka; Coble, Joseph; Stewart, Patricia

2010-01-01

Background Diesel exhaust (DE) is classified as a probable human carcinogen. Aims were to describe the major occupational uses of diesel engines and give an overview of personal DE exposure levels and determinants of exposure as reported in the published literature. Methods Measurements representative of personal DE exposure were abstracted from the literature for the following agents: elemental carbon (EC), particulate matter (PM), carbon monoxide (CO), nitrogen oxide (NO), and nitrogen dioxide (NO2). Information on determinants of exposure was abstracted. Results In total, 3528 EC, 4166 PM, 581 CO, 322 NO, and 1404 NO2 measurements were abstracted. From the 10,001 measurements, 32% represented exposure from on-road vehicles, and 68% from off-road vehicles (30% mining, 15% railroad, and 22% other). Highest levels were reported for enclosed underground work sites where heavy equipment is used: mining, mine maintenance, and construction, (EC: 27-658 μg/m3). Intermediate exposure levels were generally reported for above ground (semi-)enclosed areas where smaller equipment was run: mechanics in a shop, emergency workers in fire stations, distribution workers at a dock, and workers loading/unloading inside a ferry (generally: EC< 50 μg/m3). Lowest levels were reported for enclosed areas separated from the source such as drivers and train crew, or outside such as surface mining, parking attendants, vehicle testers, utility service workers, surface construction and airline ground personnel (EC<25 μg/m3). The other agents showed a similar pattern. Determinants of exposure reported for enclosed situations were ventilation and exhaust after treatment devices. Conclusions Reported DE exposure levels were highest for underground mining and construction, intermediate for working in above ground (semi-)enclosed areas and lowest for working outside or separated from the source. The presented data can be used as a basis for assessing occupational exposure in population-based epidemiological studies and guide future exposure assessment efforts for industrial hygiene and epidemiological studies. PMID:19277070

Do ambient noise exposure levels predict hearing loss in a modern industrial cohort?

PubMed Central

Rabinowitz, P M; Galusha, D; Dixon‐Ernst, C; Slade, M D; Cullen, M R

2007-01-01

Background Much of what is known about the exposure–response relationship between occupational noise exposures and hearing loss comes from cross‐sectional studies conducted before the widespread implementation of workplace hearing conservation programmes. Little is known about the current relationship of ambient noise exposure measurements to hearing loss risk. Aim To examine the relationship between rates of high frequency hearing loss and measured levels of noise exposure in a modern industrial workforce. Methods Ten‐year hearing loss rates were determined for 6217 employees of an aluminium manufacturing company. Industrial hygiene and human resources records allowed for reconstruction of individual noise exposures. Hearing loss rates were compared to ANSI 3.44 predictions based on age and noise exposure. Associations between hearing loss, noise exposure, and covariate risk factors were assessed using multivariate regression. Results Workers in higher ambient noise jobs tended to experience less high frequency hearing loss than co‐workers exposed at lower noise levels. This trend was also seen in stratified analyses of white males and non‐hunters. At higher noise exposure levels, the magnitude of hearing loss was less than predicted by ANSI 3.44 formulae. There was no indication that a healthy worker effect could explain these findings. The majority of 10 dB standard threshold shifts (STS) occurred in workers whose calculated ambient noise exposures were less than or equal to 85 dBA. Conclusions In this modern industrial cohort, hearing conservation efforts appear to be reducing hearing loss rates, especially at higher ambient noise levels. This could be related to differential use of hearing protection. The greatest burden of preventable occupational hearing loss was found in workers whose noise exposure averaged 85 dBA or less. To further reduce rates of occupational hearing loss, hearing conservation programmes may require innovative approaches targeting workers with noise exposures close to 85 dBA. PMID:16973736

Gestational exposure to urban air pollution related to a decrease in cord blood vitamin d levels.

PubMed

Baïz, Nour; Dargent-Molina, Patricia; Wark, John D; Souberbielle, Jean-Claude; Slama, Rémy; Annesi-Maesano, Isabella

2012-11-01

Vitamin D deficiency has been implicated in the increased risk of several diseases. Exposure to air pollution has been suggested as a contributor to vitamin D deficiency. However, studies that have examined the effects of air pollution on vitamin D status are few and have never focused on prenatal life as an exposure window. Our aim was to investigate the associations between gestational exposure to urban air pollutants and 25-hydroxyvitamin D [25(OH)D] cord blood serum level in 375 mother-child pairs of the EDEN birth cohort. The Atmospheric Dispersion Modelling System (ADMS-Urban) pollution model, a validated dispersion model combining data on traffic conditions, topography, meteorology, and background pollution, was used to assess the concentrations of two major urban pollutants, particulate matter less than 10 μm in diameter (PM(10)) and nitrogen dioxide (NO(2)), at the mother's home address during pregnancy. Cord blood samples were collected at birth and were analyzed for levels of 25(OH)D. Maternal exposure to ambient urban levels of NO(2) and PM(10) during the whole pregnancy was a strong predictor of low vitamin D status in newborns. After adjustment, log-transformed 25(OH)D decreased by 0.15 U (P = 0.05) and 0.41 U (P = 0.04) for a 10-μg/m(3) increase in NO(2) and PM(10) pregnancy levels, respectively. The association was strongest for third-trimester exposures (P = 0.0003 and P = 0.004 for NO(2) and PM(10), respectively). Gestational exposure to ambient urban air pollution, especially during late pregnancy, may contribute to lower vitamin D levels in offspring. This could affect the child's risk of developing diseases later in life.

The Impact of Different Permissible Exposure Limits on Hearing Threshold Levels Beyond 25 dBA

PubMed Central

Sayapathi, Balachandar S; Su, Anselm Ting; Koh, David

2014-01-01

Background: Development of noise-induced hearing loss is reliant on a few factors such as frequency, intensity, and duration of noise exposure. The occurrence of this occupational malady has doubled from 120 million to 250 million in a decade. Countries such as Malaysia, India, and the US have adopted 90 dBA as the permissible exposure limit. According to the US Occupational Safety and Health Administration (OSHA), the exposure limit for noise is 90 dBA, while that of the US National Institute of Occupational Safety and Health (NIOSH) is 85 dBA for 8 hours of noise exposure. Objectives: This study aimed to assess the development of hearing threshold levels beyond 25 dBA on adoption of 85 dBA as the permissible exposure limit compared to 90 dBA. Patients and Methods: This is an intervention study done on two automobile factories. There were 203 employees exposed to noise levels beyond the action level. Hearing protection devices were distributed to reduce noise levels to a level between the permissible exposure limit and action level. The permissible exposure limits were 90 and 85 dBA in factories 1 and 2, respectively, while the action levels were 85 and 80 dBA, respectively. The hearing threshold levels of participants were measured at baseline and at first month of postshift exposure of noise. The outcome was measured by a manual audiometer. McNemar and chi-square tests were used in the statistical analysis. Results: We found that hearing threshold levels of more than 25 dBA has changed significantly from pre-intervention to post-intervention among participants from both factories (3000 Hz for the right ear and 2000 Hz for the left ear). There was a statistically significant association between participants at 3000 Hz on the right ear at ‘deteriorated’ level ( χ² (1) = 4.08, φ = - 0.142, P = 0.043), whereas there was worsening of hearing threshold beyond 25 dBA among those embraced 90 dBA. Conclusions: The adoption of 85 dBA as the permissible exposure limit has preserved hearing threshold level among participants at 3000 Hz compared to those who embraced 90 dBA. PMID:25763196

A Systematic Review of Radon Investigations Related to Public Exposure in Iran

PubMed Central

Pirsaheb, Meghdad; Najafi, Farid; Khosravi, Touba; Hemati, Lida

2013-01-01

Background The main sources of radiation exposure of all living organisms including humans are natural. In fact, radon and its decay products are the cause of 50% of the total dose that is derived from natural sources. Because of the significant health hazards of radon gas, its levels are widely monitored throughout the world. Accordingly, considerable researches have also been carried out in Iran. Objectives The aim of this research is a systematic review of the most recent studies associated with evaluation of radon gas levels in Iran. The main emphasis of this study was on public exposure to radon gas. Materials and Methods The most important route of exposure to such radiation is indoor places. In this investigation measurement of radon in water resources, tap water, indoor places and exhalation of radon from building material, the major sources of indoor radon gas emission, were considered. Results Significantly high levels of radon gas were found mostly in water and residenvial buildings. Conclusions It conclusion with regard to the study of building materials, granite stone and adobe coverings cannot be recommended for construction purposes. PMID:24719680

ACUTE RESPIRATORY HEALTH EFFECTS OF AIR POLLUTION ON ASTHMATIC CHILDREN IN US INNER CITIES

EPA Science Inventory

BACKGROUND: Children with asthma in inner-city communities may be particularly vulnerable to adverse effects of air pollution because of their airways disease and exposure to relatively high levels of motor vehicle emissions. OBJECTIVE: To investigate the association between fluc...

Arsenic exposure through drinking water increases the risk of liver and cardiovascular diseases in the population of West Bengal, India

PubMed Central

2012-01-01

Background Arsenic is a natural drinking water contaminant affecting 26 million people in West Bengal, India. Chronic arsenic exposure causes cancer, cardiovascular disease, liver disease, neuropathies and ocular diseases. The aims of the present study were to assess bioindicators of hepatocellular injury as indicated by the levels of liver enzymes, to determine the auto immune status, as indicated by the amounts of anti-nuclear antibodies (ANA) and anti-dsDNA antibodies in their serum, and to predict cardiovascular risk in the arsenic exposed population. Methods Effect of chronic arsenic exposure on liver was determined by liver function tests. Autoimmune status was measured by measuring ANA and anti-dsDNA in serum. Inflammatory cytokines associated with increased cardiovascular disease risk, IL6, IL8 and MCP-1 were determined. Results Our results indicated that serum levels of bilirubin, alanine transaminase, aspartate transaminase, alkaline phosphatase and ANA were increased in the arsenic exposed population. Serum levels of IL6 and IL8 also increased in the arsenic exposed group. Conclusions Chronic arsenic exposure causes liver injury, increases the serum levels of autoimmune markers and imparts increased cardiovascular risk. PMID:22883023

Metallothionein as potential biomarker of cadmium exposure in Persian sturgeon (Acipenser persicus).

PubMed

Shariati, Fatemeh; Esaili Sari, Abbas; Mashinchian, Ali; Pourkazemi, Mohammad

2011-10-01

Metallothionein (MT) concentration in gills, liver, and kidney tissues of Persian sturgeon (Acipenser persicus) were determined following exposure to sublethal levels of waterborne cadmium (Cd) (50, 400, and 1,000 μg l(-1)) after 1, 2, 4, and 14 days. The increases of MT from background levels were 4.6-, 3-, and 2.8-fold for kidney, liver, and gills, respectively. The results showed that MT level change in the kidney is time and concentration dependent. Also, cortisol measurement revealed elevation at the day 1 of exposure and followed by MT increase in the liver. Cd concentrations in the cytosol of experimental tissues were measured, and the results indicated that Cd levels in the cytosol of liver, kidney, and gills increased 240.71-, 32.05-, and 40.16-fold, respectively, 14 days after exposure to 1,000 μg l(-1) Cd. The accumulation of Cd in cytosol of tissues is in the order of liver > gills > kidney. Pearson correlation coefficients showed that the MT content in kidney is correlated with Cd concentration, the value of which is more than in liver and gills. Thus, kidney can be considered as a tissue indicator in A. persicus for waterborne Cd contamination.

Father's occupational exposure to carcinogenic agents and childhood acute leukemia: a new method to assess exposure (a case-control study)

PubMed Central

Perez-Saldivar, Maria Luisa; Ortega-Alvarez, Manuel Carlos; Fajardo-Gutierrez, Arturo; Bernaldez-Rios, Roberto; del Campo-Martinez, Maria de los Angeles; Medina-Sanson, Aurora; Palomo-Colli, Miguel Angel; Paredes-Aguilera, Rogelio; Martínez-Avalos, Armando; Borja-Aburto, Victor Hugo; Rodriguez-Rivera, Maria de Jesus; Vargas-Garcia, Victor Manuel; Zarco-Contreras, Jesus; Flores-Lujano, Janet; Mejia-Arangure, Juan Manuel

2008-01-01

Background Medical research has not been able to establish whether a father's occupational exposures are associated with the development of acute leukemia (AL) in their offspring. The studies conducted have weaknesses that have generated a misclassification of such exposure. Occupations and exposures to substances associated with childhood cancer are not very frequently encountered in the general population; thus, the reported risks are both inconsistent and inaccurate. In this study, to assess exposure we used a new method, an exposure index, which took into consideration the industrial branch, specific position, use of protective equipment, substances at work, degree of contact with such substances, and time of exposure. This index allowed us to obtain a grade, which permitted the identification of individuals according to their level of exposure to known or potentially carcinogenic agents that are not necessarily specifically identified as risk factors for leukemia. The aim of this study was to determine the association between a father's occupational exposure to carcinogenic agents and the presence of AL in their offspring. Methods From 1999 to 2000, a case-control study was performed with 193 children who reside in Mexico City and had been diagnosed with AL. The initial sample-size calculation was 150 children per group, assessed with an expected odds ratio (OR) of three and a minimum exposure frequency of 15.8%. These children were matched by age, sex, and institution with 193 pediatric surgical patients at secondary-care hospitals. A questionnaire was used to determine each child's background and the characteristics of the father's occupation(s). In order to determine the level of exposure to carcinogenic agents, a previously validated exposure index (occupational exposure index, OEI) was used. The consistency and validity of the index were assessed by a questionnaire comparison, the sensory recognition of the work area, and an expert's opinion. Results The adjusted ORs and 95% confidence intervals (CI) were 1.69 (0.98, 2.92) during the preconception period; 1.98 (1.13, 3.45) during the index pregnancy; 2.11 (1.17, 3.78) during breastfeeding period; 2.17 (1.28, 3.66) after birth; and 2.06 (1.24, 3.42) for global exposure. Conclusion This is the first study in which an OEI was used to assess a father's occupational exposure to carcinogenic agents as a risk factor for the development of childhood AL in his offspring. From our results, we conclude that children whose fathers have been exposed to a high level of carcinogenic agents seem to have a greater risk of developing acute leukemia. However, confounding factors cannot be disregarded due to an incomplete control for confounding. PMID:18194546

Background noise analysis in urban airport surroundings of Brazilian cities, Congonhas Airport, São Paulo

PubMed Central

Scatolini, Fabio; Alves, Cláudio Jorge Pinto

2016-01-01

ABSTRACT OBJECTIVE To perform a quantitative analysis of the background noise at Congonhas Airport surroundings based on large sampling and measurements with no interruption. METHODS Measuring sites were chosen from 62 and 72 DNL (day-night-level) noise contours, in urban sites compatible with residential use. Fifteen sites were monitored for at least 168 hours without interruption or seven consecutive days. Data compilation was based on cross-reference between noise measurements and air traffic control records, and results were validated by airport meteorological reports. Preliminary diagnoses were established using the standard NBR-13368. Background noise values were calculated based on the Sound Exposure Level (SEL). Statistic parameters were calculated in one-hour intervals. RESULTS Only four of the fifteen sites assessed presented aircraft operations as a clear cause for the noise annoyance. Even so, it is possible to detect background noise levels above regulation limits during periods of low airport activity or when it closes at night. CONCLUSIONS All the sites monitored showed background noise levels above regulation limits between 7:00 and 21:00. In the intervals between 6:00-6:59 and 21:00-22:59 the noise data, when analyzed with the current airport operational characteristics, still allow the development of additional mitigating measures. PMID:28099658

Evaluation of workplace exposure to respirable crystalline silica in Italy

PubMed Central

Scarselli, Alberto; Corfiati, Marisa; Marzio, Davide Di; Iavicoli, Sergio

2014-01-01

Background: Crystalline silica is a human carcinogen and its use is widespread among construction, mining, foundries, and other manufacturing industries. Purpose: To evaluate occupational exposure to crystalline silica in Italy. Methods: Data were collected from exposure registries and descriptive statistics were calculated for exposure-related variables. The number of potentially exposed workers was estimated in a subset of industrial sectors. Linear mixed model analysis was performed to determine factors affecting the exposure level. Results: We found 1387 cases of crystalline silica exposure between 1996 and 2012. Exposure was most common in construction work (AM = 0.057 mg/m3, N = 505), and among miners and quarry workers (AM = 0.048 mg/m3, N = 238). We estimated that 41 643 workers were at risk of exposure in the selected industrial sectors during the same period. Conclusions: This study identified high-risk sectors for occupational exposure to crystalline silica, which can help guide targeted dust control interventions and health promotion campaigns in the workplace. PMID:25078346

Comparison of user volume control settings for portable music players with three earphone configurations in quiet and noisy environments.

PubMed

Henry, Paula; Foots, Ashley

2012-03-01

Listening to music is one of the most common forms of recreational noise exposure. Previous investigators have demonstrated that maximum output levels from headphones can exceed safe levels. Although preferred listening levels (PLL) in quiet environments may be at acceptable levels, the addition of background noise will add to the overall noise exposure of a listener. Use of listening devices that block out some of the background noise would potentially allow listeners to select lower PLLs for their music. Although one solution is in-the-ear earphones, an alternative solution is the use of earmuffs in conjunction with earbuds. There were two objectives to this experiment. The first was to determine if an alternative to in-the-ear earphones for noise attenuation (the addition of earmuffs to earbuds) would allow for lower PLLs through a portable media player (PMP) than earbuds. The second was to determine if a surrounding background noise would yield different PLLs than a directional noise source. This was an experimental study. Twenty-four adults with normal hearing. PLLs were measured for three earphone configurations in three listening conditions. The earphone configurations included earbuds, canal earphones, and earbuds in combination with hearing protection devices (HPDs). The listening conditions included quiet, noise from one loudspeaker, and noise from four surrounding loudspeakers. Participants listened in each noise and earphone combination for as long as they needed to determine their PLL for that condition. Once the participant determined their PLL, investigators made a 5 sec recording of the music through a probe tube microphone. The average PLLs in each noise and earphone combination were used as the dependent variable. Ear canal level PLLs were converted to free-field equivalents to compare to noise exposure standards and previously published data. The average PLL as measured in the ear canal was 74 dBA in the quiet conditions and 84 dBA in the noise conditions. Paired comparisons of the PLL in the presence of background noise for each pair of earphone configurations indicated significant differences for each comparison. An inverse relationship was observed between attenuation and PLL whereby the greater the attenuation, the lower the PLL. A comparison of the single noise source condition versus the surrounding noise condition did not result in a significant effect. The present work suggests that earphones that take advantage of noise attenuation can reduce the level at which listeners set music in the presence of background noise. An alternative to in-the-ear earphones for noise attenuation is the addition of earmuffs to earbuds. American Academy of Audiology.

Exposure to dust mite allergen and endotoxin in early life and asthma and atopy in childhood

PubMed Central

Celedón, Juan C.; Milton, Donald K.; Ramsey, Clare D.; Litonjua, Augusto A.; Ryan, Louise; Platts-Mills, Thomas A. E.; Gold, Diane R.

2013-01-01

Background There has been no longitudinal study of the relation between concurrent exposure to dust mite allergen and endotoxin in early life and asthma and atopy at school age. Objectives To examine the relation between exposure to dust mite allergen and endotoxin at age 2 to 3 months and asthma, wheeze, and atopy in high-risk children. Methods Birth cohort study of 440 children with parental history of atopy in the Boston metropolitan area. Results In multivariate analyses, early exposure to high levels of dust mite allergen (≥10 μg/g) was associated with increased risks of asthma at age 7 years (odds ratio [OR], 3.0; 95% CI, 1.1-7.9) and late-onset wheeze (OR, 5.0; 95% CI, 1.5-16.4). Exposure to endotoxin levels above the lowest quartile at age 2 to 3 months was associated with reduced odds of atopy at school age (OR, 0.5; 95% CI, 0.2-0.9). In contrast with its inverse association with atopy, endotoxin exposure in early life was associated with an increased risk of any wheeze between ages 1 and 7 years that did not change significantly with time (hazard ratio for each quartile increment in endotoxin levels, 1.23; 95% CI, 1.07-1.43). Conclusion Among children at risk of atopy, early exposure to high levels of dust mite allergen is associated with increased risks of asthma and late-onset wheeze. In these children, endotoxin exposure is associated with a reduced risk of atopy but an increased risk of wheeze. Clinical implications Early endotoxin exposure may be a protective factor against atopy but a risk factor for wheeze in high-risk children. PMID:17507083

Air pollution exposure--a trigger for myocardial infarction?

PubMed

Berglind, Niklas; Ljungman, Petter; Möller, Jette; Hallqvist, Johan; Nyberg, Fredrik; Rosenqvist, Mårten; Pershagen, Göran; Bellander, Tom

2010-04-01

The association between ambient air pollution exposure and hospitalization for cardiovascular events has been reported in several studies with conflicting results. A case-crossover design was used to investigate the effects of air pollution in 660 first-time myocardial infarction cases in Stockholm in 1993-1994, interviewed shortly after diagnosis using a standard protocol. Air pollution data came from central urban background monitors. No associations were observed between the risk for onset of myocardial infarction and two-hour or 24-hour air pollution exposure. No evidence of susceptible subgroups was found. This study provides no support that moderately elevated air pollution levels trigger first-time myocardial infarction.

Interaction between air pollution exposure and genes in relation to levels of inflammatory markers and risk of myocardial infarction

PubMed Central

Panasevich, Sviatlana; Leander, Karin; Ljungman, Petter; Bellander, Tom; de Faire, Ulf; Pershagen, Göran; Nyberg, Fredrik

2013-01-01

Objectives Air pollution exposure induces cardiovascular effects, possibly via systemic inflammation and coagulation misbalance. Genetic variation may determine individual susceptibility. Our aim was to investigate effect modification by inflammation (Interleukin6 (IL6), tumour necrosis factor-α (TNF-α)) and coagulation (fibrinogen Bβ, plasminogen activator inhibitor-1 (PAI-1)) gene variants on the effect of long-term or short-term air pollution exposure on both blood marker levels and non-fatal myocardial infarction (MI) risk. Design Population-based case–control study with a nested case-crossover study. Gene-environment interactions for short-term and long-term air pollution on blood marker levels were studied in population controls, for long-term exposure on MI risk using case–control design, and for short-term exposure on MI onset using case-crossover design. Setting The Stockholm Heart Epidemiology Programme (SHEEP) conducted in 1992–1994 in Stockholm, Sweden. Spatial modelling was used to assess long-term (up to 30 years retrospectively) air pollution exposure to traffic-NO2 and heating-SO2 emissions at home addresses. Urban background NO2, SO2, PM10 and O3 measurements were used to estimate short-term (up to 5 days) air pollution exposure. Participants 1192 MI cases and 1506 population controls aged 45–70 years. Outcomes The levels of blood markers of inflammation (IL-6, TNF-α) and coagulation (fibrinogen, PAI-1) and MI risk. Results We observed gene–environment interaction for several IL6 and TNF SNPs in relation to inflammation blood marker levels. One-year traffic-NO2 exposure was associated with higher IL-6 levels with each additional IL6-174C allele, and 1-year heating-SO2 exposure with higher levels of TNF-α in TNF-308AA homozygotes versus −308G carriers. Short-term air pollution exposure also interacted with IL6 and TNF in relation to marker levels. The risk of MI followed the effect on blood markers in each genotype group. Conclusions Genetic variants in IL6 and TNF may modify effects of long-term and short-term air pollution exposure on inflammatory marker levels and MI risk. PMID:24056475

Foundations of Mathematics Achievement: Instructional Practices and Diverse Kindergarten Students

ERIC Educational Resources Information Center

Bottia, Martha Cecilia; Moller, Stephanie; Mickelson, Roslyn Arlin; Stearns, Elizabeth

2014-01-01

Analyzing Early Childhood Longitudinal Survey--Kindergarten (ECLS-K) data, we examine how exposure to instructional practices influences math test scores at the end of kindergarten for children from different racial/ethnic and socioeconomic backgrounds, and for children with different levels of math skills at kindergarten entry. We also analyze…

EXPOSURE METHOD CONSIDERATIONS FOR MEASURING VITELLOGENIN EXPRESSION IN LARVAL AND MALE FATHEAD MINNOWS (PIMEPHALES PROMELAS)

EPA Science Inventory

Our laboratory has developed methods for measuring the expression of the vitellogenin (Vg) gene in larval and adult male fathead minnows. During this development we found several conditions that affect background Vg levels and we observed preconditions for the expression of this...

Neuropsychological effects of chronic low-dose exposure to polychlorinated biphenyls (PCBs): A cross-sectional study

PubMed Central

Peper, Martin; Klett, Martin; Morgenstern, Rudolf

2005-01-01

Background Exposure to indoor air of private or public buildings contaminated with polychlorinated biphenyls (PCBs) has raised health concerns in long-term users. This exploratory neuropsychological group study investigated the potential adverse effects of chronic low-dose exposure to specific air-borne low chlorinated PCBs on well-being and behavioral measures in adult humans. Methods Thirty employees exposed to indoor air contaminated with PCBs from elastic sealants in a school building were compared to 30 non-exposed controls matched for education and age, controlling for gender (age range 37–61 years). PCB exposure was verified by external exposure data and biological monitoring (PCB 28, 101, 138, 153, 180). Subjective complaints, learning and memory, executive function, and visual-spatial function was assessed by standardized neuropsychological testing. Since exposure status depended on the use of contaminated rooms, an objectively exposed subgroup (N = 16; PCB 28 = 0.20 μg/l; weighted exposure duration 17.9 ± 7 years) was identified and compared with 16 paired controls. Results Blood analyses indicated a moderate exposure effect size (d) relative to expected background exposure for total PCB (4.45 ± 2.44 μg/l; d = 0.4). A significant exposure effect was found for the low chlorinated PCBs 28 (0.28 ± 0.25 μg/l; d = 1.5) and 101 (0.07 ± 0.09 μg/l; d = 0.7). Although no neuropsychological effects exceeded the adjusted significance level, estimation statistics showed elevated effect sizes for several variables. The objectively exposed subgroup showed a trend towards increased subjective attentional and emotional complaints (tiredness and slowing of practical activities, emotional state) as well as attenuated attentional performance (response shifting and alertness in a cued reaction task). Conclusion Chronic inhalation of low chlorinated PCBs that involved elevated blood levels was associated with a subtle attenuation of emotional well-being and attentional function. Extended research is needed to replicate the potential long-term low PCB effects in a larger sample. PMID:16236166

Methylmercury and elemental mercury differentially associate with blood pressure among dental professionals

PubMed Central

Goodrich, Jaclyn M.; Wang, Yi; Gillespie, Brenda; Werner, Robert; Franzblau, Alfred; Basu, Niladri

2013-01-01

Methylmercury-associated effects on the cardiovascular system have been documented though discrepancies exist, and most studied populations experience elevated methylmercury exposures. No paper has investigated the impact of low-level elemental (inorganic) mercury exposure on cardiovascular risk in humans. The purpose of this study was to increase understanding of the association between mercury exposure (methylmercury and elemental mercury) and blood pressure measures in a cohort of dental professionals that experience background exposures to both mercury forms. Dental professionals were recruited during the 2010 Michigan Dental Association Annual Convention. Mercury levels in hair and urine samples were analyzed as biomarkers of methylmercury and elemental mercury exposure, respectively. Blood pressure (systolic, diastolic) was measured using an automated device. Distribution of mercury in hair (mean, range: 0.45, 0.02–5.18 μg/g) and urine (0.94, 0.03–5.54 μg/L) correspond well with the US National Health and Nutrition Examination Survey. Linear regression models revealed significant associations between diastolic blood pressure (adjusted for blood pressure medication use) and hair mercury (n = 262, p = 0.02). Urine mercury results opposed hair mercury in many ways. Notably, elemental mercury exposure was associated with a significant systolic blood pressure decrease (n = 262, p = 0.04) that was driven by the male population. Associations between blood pressure and two forms of mercury were found at exposure levels relevant to the general population, and associations varied according to type of mercury exposure and gender. PMID:22494934

Combined effect of urinary monohydroxylated polycyclic aromatic hydrocarbons and impaired lung function on diabetes.

PubMed

Hou, Jian; Sun, Huizhen; Xiao, Lili; Zhou, Yun; Yin, Wenjun; Xu, Tian; Cheng, Juan; Chen, Weihong; Yuan, Jing

2016-07-01

Associations of type 2 diabetes with exposure to polycyclic aromatic hydrocarbons and reduced lung function have been reported. The aim of the present study was to investigate effect of reduced lung function and exposure to background PAHs on diabetes. A total of 2730 individuals were drawn from the Wuhan-Zhuhai (WHZH) Cohort Study (n=3053). Participants completed physical examination, measurement of lung function and urinary monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs). Risk factors for type 2 diabetes were identified by multiple logistic regression analysis, and the presence of additive interaction between levels of urinary OH-PAHs and lower lung function was evaluated by calculation of the relative excess risk due to interaction (RERI) and attributable proportion due to interaction (AP). Urinary OH-PAHs levels was positively associated with type 2 diabetes among individuals with impaired lung function (p<0.05). Forced expiratory volume in one second (FEV1, odd ratio (OR): 0.664, 95% confidence interval (CI): 0.491-0.900) and forced vital capacity (FVC, OR: 0.693, 95% CI: 0.537-0.893) were negatively associated with diabetes among individuals. Additive interaction of higher urinary levels of OH-PAHs and lower FVC (RERI: 0.679, 95% CI: 0.120-1.238); AP: 0.427, 95% CI: 0.072-0.782) was associated with diabetes. Exposure to background PAHs was related to diabetes among individuals with lower lung function. Urinary levels of OH-PAHs and reduced lung function had an additive effect on diabetes. Copyright © 2016 Elsevier Inc. All rights reserved.

Characterization of pesticide exposure in a sample of pregnant women in Ecuador

PubMed Central

Handal, Alexis J.; Hund, Lauren; Páez, Maritza; Bear, Samantha; Greenberg, Carolyn; Fenske, Richard A.; Barr, Dana Boyd

2015-01-01

Background Few studies have detailed the prenatal pesticide exposure levels of women employed in or residing near large-scale agricultural industries. This study reports pesticide metabolite levels during and shortly after pregnancy in a pilot study of workers in Ecuador. Methods Urine samples were collected for 16 rose workers and 10 non-agricultural workers enrolled into the study in early pregnancy. We measured six nonspecific organophosphate dialkylphosphate (DAP) pesticide metabolites, two alkylenebis-dithiocarbamate pesticide metabolites (ethylene thiourea [ETU] and propylene thiourea [PTU]), 3,5,6-trichloro-2-pyridinol [TCPy], malathion dicarboxylic acid, and two pyrethroid metabolites (2,2-dimethylcyclopropanecarboxylic acid and 3-phenooxybenzoic acid). Results We collected 141 urine samples (mean: 5.4 per woman). We observed high detection frequencies for five DAP metabolites and ETU, PTU, and TCPy. We report elevated levels of ETU in the entire sample (median 4.24 ng/mL, IQR 2.23, 7.18), suggesting other possible non-occupational pathways of exposure. We found no statistical differences in pesticide levels by current employment status, though the highest pesticide levels were among rose workers. We observed within-woman correlation in TCPy and PTU levels, but not in ETU or DAP levels. Conclusions The present study is the first to characterize prenatal pesticide exposure levels among working women in Ecuador. Limitations include a small sample size and use of a convenience sample. Strengths include a longitudinal design and multiple urine samples per woman. Results provide an initial characterization of prenatal pesticide exposure levels and how these levels vary over pregnancy in a community impacted by agricultural industry and will inform further studies in the region. PMID:26311023

Workplace Measurements of Ultrafine Particles-A Literature Review.

PubMed

Viitanen, Anna-Kaisa; Uuksulainen, Sanni; Koivisto, Antti J; Hämeri, Kaarle; Kauppinen, Timo

2017-08-01

Workers are exposed to ultrafine particles (UFP) in a number of occupations. In order to summarize the current knowledge regarding occupational exposure to UFP (excluding engineered nanoparticles), we gathered information on UFP concentrations from published research articles. The aim of our study was to create a basis for future epidemiological studies that treat UFP as an exposure factor. The literature search found 72 publications regarding UFP measurements in work environments. These articles covered 314 measurement results and tabled concentrations. Mean concentrations were compared to typical urban UFP concentration level, which was considered non-occupational background concentration. Mean concentrations higher than the typical urban UFP concentration were reported in 240 workplace measurements. The results showed that workers' exposure to UFP may be significantly higher than their non-occupational exposure to background concentration alone. Mean concentrations of over 100 times the typical urban UFP concentration were reported in welding and metal industry. However, according to the results of the review, measurements of the UFP in work environments are, to date, too limited and reported too heterogeneous to allow us to draw general conclusions about workers' exposure. Harmonization of measurement strategies is essential if we are to generate more reliable and comparable data in the future. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Lipid Adjustment for Chemical Exposures: Accounting for Concomitant Variables

PubMed Central

Li, Daniel; Longnecker, Matthew P.; Dunson, David B.

2013-01-01

Background Some environmental chemical exposures are lipophilic and need to be adjusted by serum lipid levels before data analyses. There are currently various strategies that attempt to account for this problem, but all have their drawbacks. To address such concerns, we propose a new method that uses Box-Cox transformations and a simple Bayesian hierarchical model to adjust for lipophilic chemical exposures. Methods We compared our Box-Cox method to existing methods. We ran simulation studies in which increasing levels of lipid-adjusted chemical exposure did and did not increase the odds of having a disease, and we looked at both single-exposure and multiple-exposures cases. We also analyzed an epidemiology dataset that examined the effects of various chemical exposures on the risk of birth defects. Results Compared with existing methods, our Box-Cox method produced unbiased estimates, good coverage, similar power, and lower type-I error rates. This was the case in both single- and multiple-exposure simulation studies. Results from analysis of the birth-defect data differed from results using existing methods. Conclusion Our Box-Cox method is a novel and intuitive way to account for the lipophilic nature of certain chemical exposures. It addresses some of the problems with existing methods, is easily extendable to multiple exposures, and can be used in any analyses that involve concomitant variables. PMID:24051893

Temporal variability of the quality of Taraxacum officinale seed progeny from the East-Ural radioactive trace: is there an interaction between low level radiation and weather conditions?

PubMed

Pozolotina, Vera N; Antonova, Elena V

2017-03-01

The multiple stressors, in different combinations, may impact differently upon seed quality, and low-level doses of radiation may enhance synergistic or antagonistic effects. During 1991-2014 we investigated the quality of the dandelion (Taraxacum officinale s.l.) seed progeny growing under low-level radiation exposure at the East-Ural Radioactive Trace (EURT) area (result of the Kyshtym accident, Russia), and in plants from areas exposed to background radiation. The viability of the dandelion seed progeny was assessed according to chronic radiation exposure, accounting for the variability of weather conditions among years. Environmental factors (temperature, precipitation, and their ratio in different months) can modify the radiobiological effects. We found a wide range of possible responses to multiple stressors: inhibition, stimulation, and indifferent effects in different seasons. The intraspecific variability of the quality of dandelion seed progeny was greatly increased under conditions of low doses of chronic irradiation. Temperature was the most significant factor for seed progeny formation in the EURT zone, whereas the sums of precipitation and ratios of precipitation to temperature dominantly affected organisms from the background population.

Just who is at risk? The ethics of environmental regulation.

PubMed

Simon, Ted

2011-08-01

The willingness to view risk as part of daily life has vanished. A risk-averse mindset among environmental regulators engenders confusion between the ethics of intention and the ethics of consequence, leading to the elevation of the precautionary principle with unintended and often unfortunate outcomes. Environmental risk assessment is conservative, but the actual level of conservatism cannot be determined. High-end exposure assumptions and current toxicity criteria from the USEPA, based on linear extrapolation for carcinogens and default uncertainty factors for systemic toxicants, obscure the degree of conservatism in risk assessments. Ideally, one could choose a percentile of the target population to include within environmental standards, but this choice is complicated by the food, pharmaceutical and advertising industries, whose activities, inadvertent or not, often promote maladaptive and unhealthy lifestyle choices. There has lately been much discussion about background exposures and disease processes and their potential to increase the risk from environmental chemicals. Should these background exposures or disease processes, especially those associated with maladaptive individual choices, be included as part of a regulatory risk evaluation? A significant ethical question is whether environmental regulation should protect those pursuing a self-destructive lifestyle that may add to or synergize with otherwise innocuous environmental exposures. Choosing a target percentile of protection would provide an increased level of transparency and the flexibility to choose a higher or lower percentile if such a choice is warranted. Transparency and flexibility will lead to more responsive environmental regulation that balances protection of public health and the stewardship of societal resources.

Quantitation of biomarkers of exposure to nitrogen mustards in urine from rats dosed with nitrogen mustards and from an unexposed human population.

PubMed

Lemire, Sharon W; Barr, John R; Ashley, David L; Olson, Carl T; Hayes, Timothy L

2004-01-01

The nitrogen mustards bis(2-chloroethyl)ethylamine (HN1), bis(2-chloroethyl)methylamine (HN2), and tris(2-chloroethyl)amine (HN3) have the potential to be used as chemical terrorism agents because of their extreme vesicant properties. We modified a previously reported method to incorporate automated solid-phase extraction, improve chromatography, and include the urinary metabolite for HN3. The improved method was used to measure levels of the urinary metabolites N-ethyldiethanolamine (EDEA), N-methyldiethanolamine (MDEA), and triethanolamine (TEA) in rats dosed with HN1, HN2, and HN3, respectively, and to establish background levels of EDEA, MDEA, and TEA in human urine samples from a population with no known exposure to nitrogen mustards. Rat dosing experiments confirmed that EDEA, MDEA, and TEA could be detected in urine for at least 48 h after exposure to HN1, HN2, and HN3, respectively. Substantial amounts of EDEA (89 ng/mL), MDEA (170 ng/mL), and TEA (1105 ng/mL) were measured in the urine of rats exposed to 10 mg HN1, HN2, and HN3, respectively, 48 h after exposure. The background concentrations for TEA in the human population ranged from below the limit of detection (LOD 3 ng/mL) to approximately 6500 ng/mL. Neither EDEA (LOD 0.4 ng/mL) nor MDEA (LOD 0.8 ng/mL) was detected above the LOD in the human samples.

Air pollution, health and social deprivation: A fine-scale risk assessment.

PubMed

Morelli, Xavier; Rieux, Camille; Cyrys, Josef; Forsberg, Bertil; Slama, Rémy

2016-05-01

Risk assessment studies often ignore within-city variations of air pollutants. Our objective was to quantify the risk associated with fine particulate matter (PM2.5) exposure in 2 urban areas using fine-scale air pollution modeling and to characterize how this risk varied according to social deprivation. In Grenoble and Lyon areas (0.4 and 1.2 million inhabitants, respectively) in 2012, PM2.5 exposure was estimated on a 10×10m grid by coupling a dispersion model to population density. Outcomes were mortality, lung cancer and term low birth weight incidences. Cases attributable to air pollution were estimated overall and stratifying areas according to the European Deprivation Index (EDI), taking 10µg/m(3) yearly average as reference (counterfactual) level. Estimations were repeated assuming spatial homogeneity of air pollutants within urban area. Median PM2.5 levels were 18.1 and 19.6μg/m(3) in Grenoble and Lyon urban areas, respectively, corresponding to 114 (5.1% of total, 95% confidence interval, CI, 3.2-7.0%) and 491 non-accidental deaths (6.0% of total, 95% CI 3.7-8.3%) attributable to long-term exposure to PM2.5, respectively. Attributable term low birth weight cases represented 23.6% of total cases (9.0-37.1%) in Grenoble and 27.6% of cases (10.7-42.6%) in Lyon. In Grenoble, 6.8% of incident lung cancer cases were attributable to air pollution (95% CI 3.1-10.1%). Risk was lower by 8 to 20% when estimating exposure through background stations. Risk was highest in neighborhoods with intermediate to higher social deprivation. Risk assessment studies relying on background stations to estimate air pollution levels may underestimate the attributable risk. Copyright © 2016 Elsevier Inc. All rights reserved.

Can air pollution negate the health benefits of cycling and walking?

PubMed

Tainio, Marko; de Nazelle, Audrey J; Götschi, Thomas; Kahlmeier, Sonja; Rojas-Rueda, David; Nieuwenhuijsen, Mark J; de Sá, Thiago Hérick; Kelly, Paul; Woodcock, James

2016-06-01

Active travel (cycling, walking) is beneficial for the health due to increased physical activity (PA). However, active travel may increase the intake of air pollution, leading to negative health consequences. We examined the risk-benefit balance between active travel related PA and exposure to air pollution across a range of air pollution and PA scenarios. The health effects of active travel and air pollution were estimated through changes in all-cause mortality for different levels of active travel and air pollution. Air pollution exposure was estimated through changes in background concentrations of fine particulate matter (PM2.5), ranging from 5 to 200μg/m3. For active travel exposure, we estimated cycling and walking from 0 up to 16h per day, respectively. These refer to long-term average levels of active travel and PM2.5 exposure. For the global average urban background PM2.5 concentration (22μg/m3) benefits of PA by far outweigh risks from air pollution even under the most extreme levels of active travel. In areas with PM2.5 concentrations of 100μg/m3, harms would exceed benefits after 1h 30min of cycling per day or more than 10h of walking per day. If the counterfactual was driving, rather than staying at home, the benefits of PA would exceed harms from air pollution up to 3h 30min of cycling per day. The results were sensitive to dose-response function (DRF) assumptions for PM2.5 and PA. PA benefits of active travel outweighed the harm caused by air pollution in all but the most extreme air pollution concentrations. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Estimating Pesticide Exposure from Dietary Intake and Organic Food Choices: The Multi-Ethnic Study of Atherosclerosis (MESA)

PubMed Central

Beresford, Shirley A.A.; Fenske, Richard A.; Fitzpatrick, Annette L.; Lu, Chensheng; Nettleton, Jennifer A.; Kaufman, Joel D.

2015-01-01

Background Organophosphate pesticide (OP) exposure to the U.S. population is dominated by dietary intake. The magnitude of exposure from diet depends partly on personal decisions such as which foods to eat and whether to choose organic food. Most studies of OP exposure rely on urinary biomarkers, which are limited by short half-lives and often lack specificity to parent compounds. A reliable means of estimating long-term dietary exposure to individual OPs is needed to assess the potential relationship with adverse health effects. Objectives We assessed long-term dietary exposure to 14 OPs among 4,466 participants in the Multi-Ethnic Study of Atherosclerosis, and examined the influence of organic produce consumption on this exposure. Methods Individual-level exposure was estimated by combining information on typical intake of specific food items with average OP residue levels on those items. In an analysis restricted to a subset of participants who reported rarely or never eating organic produce (“conventional consumers”), we assessed urinary dialkylphosphate (DAP) levels across tertiles of estimated exposure (n = 480). In a second analysis, we compared DAP levels across subgroups with differing self-reported organic produce consumption habits (n = 240). Results Among conventional consumers, increasing tertile of estimated dietary OP exposure was associated with higher DAP concentrations (p < 0.05). DAP concentrations were also significantly lower in groups reporting more frequent consumption of organic produce (p < 0.02). Conclusions Long-term dietary exposure to OPs was estimated from dietary intake data, and estimates were consistent with DAP measurements. More frequent consumption of organic produce was associated with lower DAPs. Citation Curl CL, Beresford SA, Fenske RA, Fitzpatrick AL, Lu C, Nettleton JA, Kaufman JD. 2015. Estimating pesticide exposure from dietary intake and organic food choices: the Multi-Ethnic Study of Atherosclerosis (MESA). Environ Health Perspect 123:475–483; http://dx.doi.org/10.1289/ehp.1408197 PMID:25650532

Effect of physical activity and sun exposure on vitamin D status of Saudi children and adolescents

PubMed Central

2012-01-01

Background Accumulating evidence suggests an increased prevalence of vitamin D deficiency in the Middle East. In this context, we aimed to determine whether the prevalence of vitamin D deficiency is related to degree of physical activity and sun exposure among apparently healthy Saudi children and adolescents, a little studied population. Methods A total of 331 Saudi children aged 6–17 years (153 boys and 178 girls) were included in this cross sectional study. Levels of physical activity and sun exposure were determined using a standard questionnaire. Anthropometry, serum calcium and 25-(OH) vitamin D were analyzed. Results All subjects were vitamin D deficient, the majority being moderately deficient (71.6%). Age was the single most significant predictor affecting 25 (OH) Vitamin D levels, explaining 21% of the variance perceived (p = 1.68 x 10-14). Age-matched comparisons revealed that for groups having the same amount of sun exposure, those with moderate or are physically active will have higher levels of vitamin D status, though levels in across groups remained deficient. Conclusion Vitamin D deficiency is common among Saudi children and adolescents, and is influenced by both sun exposure and physical activity. Promotion of an active outdoor lifestyle among Saudi children in both homes and schools may counteract the vitamin D deficiency epidemic in this vulnerable population. Vitamin D supplementation is suggested in all groups, including those with the highest sun exposure and physical activity. PMID:22759399

Occupational Exposure to Nano-Objects and Their Agglomerates and Aggregates Across Various Life Cycle Stages; A Broad-Scale Exposure Study.

PubMed

Bekker, Cindy; Kuijpers, Eelco; Brouwer, Derk H; Vermeulen, Roel; Fransman, Wouter

2015-07-01

Occupational exposure to manufactured nano-objects and their agglomerates, and aggregates (NOAA) has been described in several workplace air monitoring studies. However, data pooling for general conclusions and exposure estimates are hampered by limited exposure data across the occupational life cycle of NOAA and a lack in comparability between the methods of collecting and analysing the data. By applying a consistent method of collecting and analysing the workplace exposure data, this study aimed to provide information about the occupational NOAA exposure levels across various life cycle stages of NOAA in the Netherlands which can also be used for multi-purpose use. Personal/near field task-based exposure data was collected using a multi-source exposure assessment method collecting real time particle number concentration, particle size distribution (PSD), filter-based samples for morphological, and elemental analysis and detailed contextual information. A decision logic was followed allowing a consistent and objective way of analysing the exposure data. In total, 46 measurement surveys were conducted at 15 companies covering 18 different exposure situations across various occupational life cycle stages of NOAA. Highest activity-effect levels were found during replacement of big bags (<1000-76000 # cm(-3)), mixing/dumping of powders manually (<1000-52000 # cm(-3)) and mechanically (<1000-100000 # cm(-3)), and spraying of liquid (2000-800000 # cm(-3)) showing a high variability between and within the various exposure situations. In general, a limited change in PSD was found during the activity compared to the background. This broad-scale exposure study gives a comprehensive overview of the NOAA exposure situations in the Netherlands and an indication of the levels of occupational exposure to NOAA across various life cycle of NOAA. The collected workplace exposure data and contextual information will serve as basis for future pooling of data and modelling of worker exposure. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Exogenous and Endogenous Determinants of Blood Trihalomethane Levels after Showering

PubMed Central

Backer, Lorraine C.; Lan, Qing; Blount, Benjamin C.; Nuckols, J.R.; Branch, Robert; Lyu, Christopher W.; Kieszak, Stephanie M.; Brinkman, Marielle C.; Gordon, Sydney M.; Flanders, W. Dana; Romkes, Marjorie; Cantor, Kenneth P.

2008-01-01

Background We previously conducted a study to assess whether household exposures to tap water increased an individual’s internal dose of trihalomethanes (THMs). Increases in blood THM levels among subjects who showered or bathed were variable, with increased levels tending to cluster in two groups. Objectives Our goal was to assess the importance of personal characteristics, previous exposures, genetic polymorphisms, and environmental exposures in determining THM concentrations in blood after showering. Methods One hundred study participants completed a health symptom questionnaire, a 48-hr food and water consumption diary, and took a 10-min shower in a controlled setting. We examined THM levels in blood samples collected at baseline and 10 and 30 min after the shower. We assessed the significance of personal characteristics, previous exposures to THMs, and specific gene polymorphisms in predicting postshower blood THM concentrations. Results We did not observe the clustering of blood THM concentrations observed in our earlier study. We found that environmental THM concentrations were important predictors of blood THM concentrations immediately after showering. For example, the chloroform concentration in the shower stall air was the most important predictor of blood chloroform levels 10 min after the shower (p < 0.001). Personal characteristics, previous exposures to THMs, and specific polymorphisms in CYP2D6 and GSTT1 genes were significant predictors of both baseline and postshowering blood THM concentrations as well as of changes in THM concentrations associated with showering. Conclusion The inclusion of information about individual physiologic characteristics and environmental measurements would be valuable in future studies to assess human health effects from exposures to THMs in tap water. PMID:18197300

A study of classroom acoustics and school teachers' noise exposure, voice load and speaking time during teaching, and the effects on vocal and mental fatigue development.

PubMed

Kristiansen, Jesper; Lund, Søren Peter; Persson, Roger; Shibuya, Hitomi; Nielsen, Per Møberg; Scholz, Matthias

2014-11-01

The study investigated the noise exposure in a group of Danish school teachers. The aims were to investigate if noise posed a risk of impairment of hearing and to study the association between classroom acoustical conditions, noise exposure, vocal symptoms, and cognitive fatigue. Background noise levels, vocal load and speaking time were measured on 35 teachers during actual classroom teaching. The classrooms were characterized acoustically by measurements of reverberation time. Before and after the workday, the teachers answered a questionnaire on fatigue symptoms and carried out two cognitive test tasks sensitive to mental fatigue. The average noise level during the lessons was 72 dB(A), but during indoor sports activities the average noise level increased 6.6 dB(A). Room reverberation time (range 0.39-0.83 s) had no significant effect on the noise level. The teachers were talking with a raised voice in 61% of the time, and the vocal load increased 0.65 dB(A) per dB(A) increase in the average lesson noise level. An increase in voice symptoms during the workday correlated significantly with individual average noise exposure, and a decrease in performance in the two-back test correlated significantly with individual average vocal load. Noise exposure in general classrooms posed no risk of noise-induced hearing impairment in school teachers. However, the results provide evidence for an association between noise exposure and vocal load and development of vocal symptoms and cognitive fatigue after work.

Chronic Exposure to Ambient Ozone and Asthma Hospital Admissions among Children

PubMed Central

Lin, Shao; Liu, Xiu; Le, Linh H.; Hwang, Syni-An

2008-01-01

Background The association between chronic exposure to air pollution and adverse health outcomes has not been well studied. Objective This project investigated the impact of chronic exposure to high ozone levels on childhood asthma admissions in New York State. Methods We followed a birth cohort born in New York State during 1995–1999 to first asthma admission or until 31 December 2000. We identified births and asthma admissions through the New York State Integrated Child Health Information System and linked these data with ambient ozone data (8-hr maximum) from the New York State Department of Environmental Conservation. We defined chronic ozone exposure using three indicators: mean concentration during the follow-up period, mean concentration during the ozone season, and proportion of follow-up days with ozone levels > 70 ppb. We performed logistic regression analysis to adjust for child’s age, sex, birth weight, and gestational age; maternal race/ethnicity, age, education, insurance status, smoking during pregnancy, and poverty level; and geographic region, temperature, and copollutants. Results Asthma admissions were significantly associated with increased ozone levels for all chronic exposure indicators (odds ratios, 1.16–1.68), with a positive dose–response relationship. We found stronger associations among younger children, low sociodemographic groups, and New York City residents as effect modifiers. Conclusion Chronic exposure to ambient ozone may increase the risk of asthma admissions among children. Younger children and those in low socioeconomic groups have a greater risk of asthma than do other children at the same ozone level. PMID:19079727

The exposome concept in a human nutrigenomics study: evaluating the impact of exposure to a complex mixture of phytochemicals using transcriptomics signatures.

PubMed

van Breda, Simone G J; Wilms, Lonneke C; Gaj, Stan; Jennen, Danyel G J; Briedé, Jacob J; Kleinjans, Jos C S; de Kok, Theo M C M

2015-11-01

The application of transcriptome analyses in molecular epidemiology studies has become a promising tool in order to evaluate the impact of environmental exposures. These analyses have a great value in establishing the exposome, the totality of human exposures, both by identifying the chemical nature of the exposures and the induced molecular responses. Transcriptomic signatures can be regarded as biomarker of exposure as well as markers of effect which reflect the interaction between individual genetic background and exposure levels. However, the biological interpretation of modulated gene expression profiles is a challenging task and translating affected molecular pathways into risk assessment, for instance in terms of cancer promoting or disease preventing responses, is a far from standardised process. Here, we describe the in-depth analyses of the gene expression responses in a human dietary intervention in which the interaction between genotype and exposure to a blueberry-apple juice containing a complex mixture of phytochemicals is investigated. We also describe how data on differences in genetic background combined with different effect markers can provide a better understanding of gene-environment interactions. Pathway analyses of differentially expressed genes in combination with gene were used to identify complex but strong changes in several biological processes like immune response, cell adhesion, lipid metabolism and apoptosis. These observed changes may lead to upgraded growth control, induced immunity, reduced platelet aggregation and activation, diminished production of reactive oxidative species by platelets, blood glucose homeostasis, regulation of blood lipid levels and increased apoptosis. Our findings demonstrate that applying transcriptomics to well-controlled human dietary intervention studies can provide insight into mechanistic pathways involved in disease prevention by dietary factors. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Pixel-based CTE Correction of ACS/WFC: New Constraints from Short Darks

NASA Astrophysics Data System (ADS)

Anderson, Jay; ACS Team

2012-01-01

The original Anderson & Bedin (2010) pixel-based correction for imperfect charge-transfer efficiency (CTE) in HST's ACS was based on a study of Warm Pixels (WPs) in a series of 1000s dark exposures. WPs with more than about 25 electrons were sufficiently isolated in these images that we could examine and model their trails. However, WPs with fewer electrons than this were more plentiful and suffered from significant crowding. To remedy this, we have taken a series of shorter dark exposures: 30s, 100s, and 339s. These supplemental exposures have two benefits. The first is that in the shorter exposures, 10 electron WPs are more sparse and their trails can be measured in isolation. The second benefit is that we can now get a handle on the absolute CTE losses, since the long-dark exposures can be used to accurately predict how many counts the WPs in the short-dark exposures should see. Any missing counts are a reflection of imperfect CTE. This new absolute handle on the CTE losses allows us to probe CTE even for very low charge packets. We find that CTE losses reach a nearly pathological level for charge packets with fewer than 20 electrons. Most ACS observations have backgrounds that are higher than this, so this does not have a large impact on science. Nevertheless, understanding CTE losses at all charge-packet levels is still important, as biases and darks often have low backgrounds. We note that these WP-based approaches to understanding CTE losses could be used in laboratory studies, as well. At present, many laboratory studies focus on Iron-55 sources, which all have 1620 electrons. Astronomical sources of interest are often fainter than this. By varying the dark exposure time, a wide diversity of WP intensities can be generated and cross-checked.

The Effects of Repeated Low-Level Blast Exposure on Hearing in Marines

PubMed Central

Kubli, Lina R.; Pinto, Robin L.; Burrows, Holly L.; Littlefield, Philip D.; Brungart, Douglas S.

2017-01-01

Background: The study evaluates a group of Military Service Members specialized in blast explosive training called “Breachers” who are routinely exposed to multiple low-level blasts while teaching breaching at the U.S. Marine Corps in Quantico Virginia. The objective of this study was to determine if there are any acute or long-term auditory changes due to repeated low-level blast exposures used in training. The performance of the instructor group “Breachers” was compared to a control group, “Engineers”. Methods: A total of 11 Breachers and four engineers were evaluated in the study. The participants received comprehensive auditory tests, including pure-tone testing, speech-in-noise (SIN) measures, and central auditory behavioral and objective tests using early and late (P300) auditory evoked potentials over a period of 17 months. They also received shorter assessments immediately following the blast-exposure onsite at Quantico. Results: No acute or longitudinal effects were identified. However, there were some interesting baseline effects found in both groups. Contrary to the expected, the onsite hearing thresholds and distortion product otoacoustic emissions were slightly better at a few frequencies immediately after blast-exposure than measurements obtained with the same equipment weeks to months after each blast-exposure. Conclusions: To date, the current study is the most comprehensive study that evaluates the long-term effects of blast-exposure on hearing. Despite extensive testing to assess changes, the findings of this study suggest that the levels of current exposures used in this military training environment do not seem to have an obvious deleterious effect on hearing. PMID:28937017

Evaluation of Background Exposures of Americans to Dioxin-Like Compounds in the 1990's and the 2000's

USDA-ARS?s Scientific Manuscript database

The US Environmental Protection Agency’s 2004 Dioxin Reassessment included a characterization of background exposures to dioxin-like compounds, including an estimate of an average background intake dose and an average background body burden. These quantities were derived from data generated in the m...

Estimation of background radiation doses for the Peninsular Malaysia's population by ESR dosimetry of tooth enamel.

PubMed

Rodzi, Mohd; Zhumadilov, Kassym; Ohtaki, Megu; Ivannikov, Alexander; Bhattacharjee, Deborshi; Fukumura, Akifumi; Hoshi, Masaharu

2011-08-01

Background radiation dose is used in dosimetry for estimating occupational doses of radiation workers or determining radiation dose of an individual following accidental exposure. In the present study, the absorbed dose and the background radiation level are determined using the electron spin resonance (ESR) method on tooth samples. The effect of using different tooth surfaces and teeth exposed with single medical X-rays on the absorbed dose are also evaluated. A total of 48 molars of position 6-8 were collected from 13 district hospitals in Peninsular Malaysia. Thirty-six teeth had not been exposed to any excessive radiation, and 12 teeth had been directly exposed to a single X-ray dose during medical treatment prior to extraction. There was no significant effect of tooth surfaces and exposure with single X-rays on the measured absorbed dose of an individual. The mean measured absorbed dose of the population is 34 ± 6.2 mGy, with an average tooth enamel age of 39 years. From the slope of a regression line, the estimated annual background dose for Peninsular Malaysia is 0.6 ± 0.3 mGy y(-1). This value is slightly lower than the yearly background dose for Malaysia, and the radiation background dose is established by ESR tooth measurements on samples from India and Russia.

Population-Level Exposure to Particulate Air Pollution during Active Travel: Planning for Low-Exposure, Health-Promoting Cities

PubMed Central

Hankey, Steve; Lindsey, Greg; Marshall, Julian D.

2016-01-01

Background: Providing infrastructure and land uses to encourage active travel (i.e., bicycling and walking) are promising strategies for designing health-promoting cities. Population-level exposure to air pollution during active travel is understudied. Objectives: Our goals were a) to investigate population-level patterns in exposure during active travel, based on spatial estimates of bicycle traffic, pedestrian traffic, and particulate concentrations; and b) to assess how those exposure patterns are associated with the built environment. Methods: We employed facility–demand models (active travel) and land use regression models (particulate concentrations) to estimate block-level (n = 13,604) exposure during rush-hour (1600–1800 hours) in Minneapolis, Minnesota. We used the model-derived estimates to identify land use patterns and characteristics of the street network that are health promoting. We also assessed how exposure is correlated with indicators of health disparities (e.g., household income, proportion of nonwhite residents). Our work uses population-level rates of active travel (i.e., traffic flows) rather than the probability of walking or biking (i.e., “walkability” or “bikeability”) to assess exposure. Results: Active travel often occurs on high-traffic streets or near activity centers where particulate concentrations are highest (i.e., 20–42% of active travel occurs on blocks with high population-level exposure). Only 2–3% of blocks (3–8% of total active travel) are “sweet spots” (i.e., high active travel, low particulate concentrations); sweet spots are located a) near but slightly removed from the city-center or b) on off-street trails. We identified 1,721 blocks (~ 20% of local roads) where shifting active travel from high-traffic roads to adjacent low-traffic roads would reduce exposure by ~ 15%. Active travel is correlated with population density, land use mix, open space, and retail area; particulate concentrations were mostly unchanged with land use. Conclusions: Public health officials and urban planners may use our findings to promote healthy transportation choices. When designing health-promoting cities, benefits (physical activity) as well as hazards (air pollution) should be evaluated. Citation: Hankey S, Lindsey G, Marshall JD. 2017. Population-level exposure to particulate air pollution during active travel: planning for low-exposure, health-promoting cities. Environ Health Perspect 125:–534; http://dx.doi.org/10.1289/EHP442 PMID:27713109

Assessment of Hair Aluminum, Lead, and Mercury in a Sample of Autistic Egyptian Children: Environmental Risk Factors of Heavy Metals in Autism

PubMed Central

Mohamed, Farida El Baz; Zaky, Eman Ahmed; El-Sayed, Adel Bassuoni; Elhossieny, Reham Mohammed; Zahra, Sally Soliman; Salah Eldin, Waleed; Youssef, Walaa Yousef; Khaled, Rania Abdelmgeed; Youssef, Azza Mohamed

2015-01-01

Background and Aims. The etiological factors involved in the etiology of autism remain elusive and controversial, but both genetic and environmental factors have been implicated. The aim of this study was to assess the levels and possible environmental risk factors and sources of exposure to mercury, lead, and aluminum in children with autism spectrum disorder (ASD) as compared to their matched controls. Methods. One hundred ASD children were studied in comparison to 100 controls. All participants were subjected to clinical evaluation and measurement of mercury, lead, and aluminum through hair analysis which reflects past exposure. Results. The mean Levels of mercury, lead, and aluminum in hair of the autistic patients were significantly higher than controls. Mercury, lead, and aluminum levels were positively correlated with maternal fish consumptions, living nearby gasoline stations, and the usage of aluminum pans, respectively. Conclusion. Levels of mercury, lead, and aluminum in the hair of autistic children are higher than controls. Environmental exposure to these toxic heavy metals, at key times in development, may play a causal role in autism. PMID:26508811

In-Game Health Communication: Delivering Low-Fear Health Messages in a Low-Fear Videogame.

PubMed

Burrows, Christopher N; Blanton, Hart

2018-06-01

Prior research has demonstrated that psychological immersion (or "transportation") into virtual gaming worlds can heighten influence from health-promotion messages embedded in the backgrounds of gaming scenes. However, research to date has only studied the effectiveness of embedding graphic, fear-based messages in the background of violent, first-person videogames. This study sought to examine whether transportation into a nonviolent videogame can heighten persuasion from low-fear, nongraphic health messages. Willingness to drive under the influence of alcohol (DUI) was measured in an undergraduate sample (M AGE  = 19) at the start of the semester, and n = 220 returned 0-3 months later to play a car-racing videogame. All were randomly assigned to play either a version of the game containing background billboards that delivered simple, text-based anti-DUI messages or consumer advertising. Self-reported levels of transportation were assessed, as well as postgame willingness to DUI. Exposure to anti-DUI messages from within the game predicted lower postgame willingness to DUI. Moreover, replicating prior research, the effect of message exposure was largest among those who reported higher levels of pregame willingness to DUI, and higher levels of in-game transportation. This study replicates prior research by suggesting that immersive videogames that promote transportation can be used to effectively deliver health communications. Results also expand prior research by providing the first evidence that such effects can generalize when health messaging orients around nongraphic, lower fear messages embedded within immersive but lower fear videogames.

A record-based case-control study of natural background radiation and the incidence of childhood leukaemia and other cancers in Great Britain during 1980–2006

PubMed Central

Kendall, Gerald M.; Little, Mark P.; Wakeford, Richard; Bunch, Kathryn J.; Miles, Jon C.H.; Vincent, Timothy J.; Meara, Jill R.; Murphy, Michael F.G.

2014-01-01

We conducted a large record-based case-control study testing associations between childhood cancer and natural background radiation. Cases (27 447) born and diagnosed in Great Britain during 1980–2006 and matched cancer-free controls (36 793) were from the National Registry of Childhood Tumours. Radiation exposures were estimated for mother’s residence at the child’s birth from national databases, using the County District mean for gamma-rays, and a predictive map based on domestic measurements grouped by geological boundaries for radon. There was 12% excess relative risk (95% CI 3, 22; 2-sided p=0.01) of childhood leukaemia per millisievert of cumulative red-bone-marrow dose from gamma-radiation; the analogous association for radon was not significant, excess relative risk 3% (95% CI −4, 11; p=0.35). Associations for other childhood cancers were not significant for either exposure. Excess risk was insensitive to adjustment for measures of socio-economic status. The statistically significant leukaemia risk reported in this reasonably-powered study (power ~50%) is consistent with high dose-rate predictions. Substantial bias is unlikely, and we cannot identify mechanisms by which confounding might plausibly account for the association, which we regard as likely to be causal. The study supports the extrapolation of high dose-rate risk models to protracted exposures at natural background exposure levels. PMID:22766784

Biological Exposure Indices of Pyrrole Adducts in Serum and Urine for Hazard Assessment of n-Hexane Exposure

PubMed Central

Yin, Hongyin; Zhang, Chunling; Guo, Ying; Shao, Xiaoying; Zeng, Tao; Zhao, Xiulan; Xie, Keqin

2014-01-01

Background Pyrrole adducts might be used as a biomarker for monitoring occupational exposure to n-hexane, but the Biological Exposure Indices of pyrrole adducts in serum and urine are still unknown. The current study was designed to investigate the biological exposure limit of pyrrole adducts for hazard assessment of n-hexane. Methods Male Wistar rats were given daily dose of 500, 1000, 1500, 2000, 4000 mg/kg bw n-hexane by gavage for 24 weeks. The levels of pyrrole adducts in serum and urine were determined at 8, 24 hours postdose once a week. The Biological Exposure Indices was evaluated by neurological evaluation and the levels of pyrrole adducts. The difference in pyrrole adducts formation between humans and rats were estimated by using in vitro test. Results Dose-dependent effects were observed between the doses of n-hexane and pyrrole adducts in serum and urine, and the levels of pyrrole adduct in serum and urine approached a plateau at week 4. There was a significantly negative correlation between the time to paralysis and the level of pyrrole adducts in serum and urine, while a positive correlation between gait score and levels of pyrrole adducts in serum and urine was observed. In vitro, pyrrole adducts formed in human serum was about two times more than those in rat serum at the same level of 2,5-HD. Conclusion It was concluded that the BEIs of pyrrole adducts in humans were 23.1±5.91 nmol/ml in serum 8 h postdose, 11.7±2.64 nmol/ml in serum 24 h postdose, 253.8±36.3 nmol/ml in urine 8 h postdose and 54.6±15.42 nmol/ml in urine 24 h postdose. PMID:24465904

Evaluation of Candidate Genes for Cholinesterase Activity in Farmworkers Exposed to Organophosphorus Pesticides: Association of Single Nucleotide Polymorphisms in BCHE

PubMed Central

Howard, Timothy D.; Hsu, Fang-Chi; Grzywacz, Joseph G.; Chen, Haiying; Quandt, Sara A.; Vallejos, Quirina M.; Whalley, Lara E.; Cui, Wei; Padilla, Stephanie; Arcury, Thomas A.

2010-01-01

Background Organophosphate pesticides act as cholinesterase inhibitors. For those with agricultural exposure to these chemicals, risk of potential exposure-related health effects may be modified by genetic variability in cholinesterase metabolism. Cholinesterase activity is a useful, indirect measurement of pesticide exposure, especially in high-risk individuals such as farmworkers. To understand fully the links between pesticide exposure and potential human disease, analyses must be able to consider genetic variability in pesticide metabolism. Objectives We studied participants in the Community Participatory Approach to Measuring Farmworker Pesticide Exposure (PACE3) study to determine whether cholinesterase levels are associated with single-nucleotide polymorphisms (SNPs) involved in pesticide metabolism. Methods Cholinesterase levels were measured from blood samples taken from 287 PACE3 participants at up to four time points during the 2007 growing season. We performed association tests of cholinesterase levels and 256 SNPs in 30 candidate genes potentially involved in pesticide metabolism. A false discovery rate (FDR) p-value was used to account for multiple testing. Results Thirty-five SNPs were associated (unadjusted p < 0.05) based on at least one of the genetic models tested (general, additive, dominant, and recessive). The strongest evidence of association with cholinesterase levels was observed with two SNPs, rs2668207 and rs2048493, in the butyrylcholinesterase (BCHE) gene (FDR adjusted p = 0.15 for both; unadjusted p = 0.00098 and 0.00068, respectively). In participants with at least one minor allele, cholinesterase levels were lower by 4.3–9.5% at all time points, consistent with an effect that is independent of pesticide exposure. Conclusions Common genetic variation in the BCHE gene may contribute to subtle changes in cholinesterase levels. PMID:20529763

Formation of DNA adducts and induction of mutagenic effects in rats following 4 weeks inhalation exposure to ethylene oxide as a basis for cancer risk assessment.

PubMed

van Sittert, N J; Boogaard, P J; Natarajan, A T; Tates, A D; Ehrenberg, L G; Törnqvist, M A

2000-01-17

Ethylene oxide (EO) is mutagenic in various in vitro and in vivo test systems and carcinogenic in rodents. EO forms different adducts upon reaction with DNA, N7-(2-hydroxyethyl)guanine (N7-HEG) being the main adduct. The major objectives of this study were: (a) to determine the formation and persistence of N7-HEG adducts in liver DNA of adult male rats exposed to 0, 50, 100 and 200 ppm by inhalation (4 weeks, 5 days/week, 6 h/day) and (b) to assess dose-response relationships for Hprt gene mutations and various types of chromosomal changes in splenic lymphocytes.N7-HEG adducts were measured 5, 21, 35 and 49 days after cessation of exposure. By extrapolation, the mean concentrations of N7-HEG immediately after cessation of exposure ('day 0') to 50, 100 and 200 ppm were calculated as 310, 558 and 1202 adducts/10(8) nucleotides, respectively, while the mean concentration in control rats was 2.6 adducts/10(8) nucleotides. At 49 days, N7-HEG values had returned close to background levels. The mean levels of N-(2-hydroxyethylvaline) adducts in haemoglobin were also determined and amounted 61.7, 114 and 247 nmol/g globin, respectively. Statistically significant linear relationships were found between mean N7-HEG levels ('day 0') and Hprt mutant frequencies at expression times 21/22 and 49/50 days and between mean N7-HEG ('day 0') and sister-chromatid exchanges (SCEs) or high frequency cells (HFC) measured 5 days post-exposure. At day 21 post-exposure, SCEs and HFCs in-part persisted and were significantly correlated with persistent N7-HEG adducts. No statistically significant dose effect relationships were observed for induction of micronuclei, nor for chromosome breaks or translocations. In conclusion, this study indicates that following sub-chronic exposure, EO is only weakly mutagenic in adult rats. Using the data of this study to predict cancer risk in man resulting from low level EO exposures in conjunction with other published data, i.e., those on (a) genotoxic effects of EO in humans and rats, (b) DNA binding of other carcinogens, (c) natural background DNA binding and (d) genotoxic potency of low energy transfer (LET) radiation, it is not expected that long term occupational exposure to airborne concentrations of EO at or below 1 ppm EO produces an unacceptable increased risk in man.

Serum cotinine levels and diabetes mellitus in never smokers.

PubMed

Alshaarawy, Omayma; Elbaz, Hosam A

2015-01-01

The aim of the current study is to examine the association of environmental tobacco smoke (ETS) exposure evident by serum cotinine level, and diabetes mellitus in never smokers. Previous studies suggest that active tobacco cigarette smoking is associated with diabetes mellitus risk. However it is not clear if the low-level "background" ETS exposure is associated with diabetes among never smokers. We present evidence from five independent replications based on the US nationally representative National Health and Nutrition Examination Surveys (NHANES) conducted 2003-12. Our exposure of interest is ETS exposure among never smokers, measured by serum cotinine levels (ng/mL), and our main outcome is diabetes mellitus assessed via self-reported physician-diagnosis, current use of insulin and/or oral hypoglycemic medications, plasma fasting glucose levels ≥126mg/dL or glycohemoglobin levels ≥6.5%. The conceptual model encompassed age, sex, ethnic self-identification, education, poverty-income ratio, alcohol drinking, total cholesterol and body mass index. In never smokers, higher serum cotinine levels were positively associated with diabetes mellitus (the meta-analytic summary estimate is 1.2, 95% CI=1.1, 1.2). This association was not evident among never smokers with cotinine levels below 3ng/mL. These replications help sustain evidence of ETS-diabetes mellitus association, which might be explained by shared psychosocial characteristics. Prospective studies with appropriate biomarkers are needed to further investigate this association. Copyright © 2015 Elsevier Inc. All rights reserved.

Does neighborhood fast-food outlet exposure amplify inequalities in diet and obesity? A cross-sectional study12

PubMed Central

Forouhi, Nita G; Griffin, Simon J; Brage, Søren; Wareham, Nicholas J

2016-01-01

Background: Greater exposures to fast-food outlets and lower levels of education are independently associated with less healthy diets and obesity. Little is known about the interplay between these environmental and individual factors. Objective: The purpose of this study was to test whether observed differences in fast-food consumption and obesity by fast-food outlet exposure are moderated by educational attainment. Design: In a population-based cohort of 5958 adults aged 29–62 y in Cambridgeshire, United Kingdom, we used educational attainment–stratified regression models to estimate the food-frequency questionnaire–derived consumption of energy-dense “fast foods” (g/d) typically sold in fast-food restaurants and measured body mass index (BMI; in kg/m2) across geographic information system–derived home and work fast-food exposure quartiles. We used logistic regression to estimate the odds of obesity (BMI ≥30) and calculated relative excess risk due to interaction (RERI) on an additive scale. Participant data were collected during 2005–2013 and analyzed in 2015. Results: Greater fast-food consumption, BMI, and odds of obesity were associated with greater fast-food outlet exposure and a lower educational level. Fast-food consumption and BMI were significantly different across education groups at all levels of fast-food outlet exposure (P < 0.05). High fast-food outlet exposure amplified differences in fast-food consumption across levels of education. The relation between fast-food outlet exposure and obesity was only significant among those who were least educated (OR: 2.05; 95% CI: 1.08, 3.87; RERI = 0.88), which suggested a positive additive interaction between education and fast-food outlet exposure. Conclusion: These findings suggest that efforts to improve diets and health through neighborhood-level fast-food outlet regulation might be effective across socioeconomic groups and may serve to reduce observed socioeconomic inequalities in diet and obesity. PMID:27169835

[Radiation-induced modification of human somatic cell chromosome sensitivity to the testing mutagenic exposure of bleomycin in vitro in lung cancer patients in delayed terms following Chernobyl accident].

PubMed

Pilinskaia, M A; Dybskiĭ, S S; Dybskaia, E B; Shvaĭko, L I

2012-01-01

By using modified "G2-bleomycin sensitivity assay" above background level of cytogenetic effect considered as a marker of hidden chromosome instability (HCI) has been investigated in 3 groups--liquidators of Chernobyl accident (occupational group 1), patients with lung cancer who denied conscious contact--with ionizing radiation (group of comparison), liquidators with lung cancer (occupational group 2). Significant interindividual variations of cytogenetic effects induced with bleomycin and the lack of positive correlation between background and above background frequencies of chromosome aberrations have been shown in all observed groups. It had been established that occupational group 2 was the most burdened group by expression of the above background cytogenetic effect and, accordingly, number of persons with HCI. The data obtained permit to suggest the existence of the association between radiation-induced increase of individual sensitivity to testing mutagenic exposure and the realization of cancer in persons exposed to ionizing radiation. The results show acceptability of "G2-bleomycin sensitivity assay" under the cytogenetic examination of irradiated contingents for determining HCI as one of informative markers of predisposition to oncopathology.

Personal exposure to particulate matter in commuters using different transport modes (bus, bicycle, car and subway) in an assigned route in downtown Santiago, Chile.

PubMed

Suárez, Liliana; Mesías, Stephanie; Iglesias, Verónica; Silva, Claudio; Cáceres, Dante D; Ruiz-Rudolph, Pablo

2014-05-01

The objective of this study was to compare personal exposure to particulate matter (fine and ultrafine particles) in commuters using different transport modes (bicycle, bus, car and subway) in a busy, assigned route in downtown Santiago, Chile. Volunteers carrying personal samplers completed scheduled commutes during the morning rush hours, while central site measurements were conducted in parallel. A total of 137 valid commutes were assessed. The impact of central site, traffic and other variables was explored with regression models. PM2.5 personal concentrations were equal to or slightly above central site measurements, while UFP personal concentrations were above them. Regression models showed impacts of both background levels and traffic emissions on personal PM2.5 and UFP exposure. Traffic impacts varied with transport modes. Estimates of traffic impacts on personal PM2.5 exposure were 2.0, 13.0, 16.9 and 17.5 μg m(-3), for car, bicycle, subway and bus, respectively; while for UFP exposure were 8400, 16 200, 25 600 and 30 100 counts per cm(3), for subway, car, bicycle and bus, respectively. After controlling the central site and transport mode, higher temperatures increased PM2.5 exposure and decreased UFP ones, while the wind direction affected UFP personal exposure. In conclusion, we found significant impacts of both central site background measurements and traffic emissions on personal exposure of volunteer commuters in an assigned route in Santiago, with impacts varying with transport modes.

Prevalence and risk factors of musculoskeletal disorders among Sri Lankan rubber tappers

PubMed Central

de Silva, Vijitha; Tharindra, Hemajith; Ostbye, Truls

2016-01-01

Background Rubber tapping exposes workers to risk factors for musculoskeletal disorders (MSDs). Objectives This cross-sectional study assessed the prevalence and factors associated with MSDs among Sri Lankan rubber tappers. Methods Questionnaires were administered to 300 rubber tappers to measure MSDs and potential associated factors. Ergonomic exposure levels were measured for 90 tappers using the Quick Exposure Check instrument. MSD prevalence and prevalence ratios were calculated using log-binomial regression. Results In the past 12 months, 66% of rubber tappers in our sample experienced an MSD. Ergonomic exposure levels were high or very high in the back (94.4%), shoulders (96.7%), and neck (83.3%). Being female, older, Tamil, working two jobs, alternating tapping hands, and depression were significantly associated with increased risk of MSDs. Conclusions MSDs are common among rubber tappers in Sri Lanka. These results suggest a need for work process modifications to prevent MSDs. PMID:27092589

Human response to high-background radiation environments on Earth and in space

NASA Astrophysics Data System (ADS)

Durante, M.; Manti, L.

2008-09-01

The main long-term objective of the space exploration program is the colonization of the planets of the Solar System. The high cosmic radiation equivalent dose rate represents an inescapable problem for the safe establishment of permanent human settlements on these planets. The unshielded equivalent dose rate on Mars ranges between 100 and 200 mSv/year, depending on the Solar cycle and altitude, and can reach values as high as 360 mSv/year on the Moon. The average annual effective dose on Earth is about 3 mSv, nearly 85% of which comes from natural background radiation, reduced to less than 1 mSv if man-made sources and the internal exposure to Rn daughters are excluded. However, some areas on Earth display anomalously high levels of background radiation, as is the case with thorium-rich monazite bearing sand deposits where values 200 400 times higher than the world average can be found. About 2% of the world’s population live above 3 km and receive a disproportionate 10% of the annual effective collective dose due to cosmic radiation, with a net contribution to effective dose by the neutron component which is 3 4 fold that at sea level. Thus far, epidemiological studies have failed to show any adverse health effects in the populations living in these terrestrial high-background radiation areas (HBRA), which provide an unique opportunity to study the health implications of an environment that, as closely as possibly achievable on Earth, resembles the chronic exposure of future space colonists to higher-than-normal levels of ionizing radiation. Chromosomal aberrations in the peripheral blood lymphocytes from the HBRA residents have been measured in several studies because chromosomal damage represents an early biomarker of cancer risk. Similar cytogenetic studies have been recently performed in a cohort of astronauts involved in single or repeated space flights over many years. The cytogenetic findings in populations exposed to high dose-rate background radiation on Earth or in space will be discussed.

Incorporating Unstructured Socializing Into the Study of Secondary Exposure to Community Violence: Etiological and Empirical Implications.

PubMed

Zimmerman, Gregory M; Messner, Steven F; Rees, Carter

2014-07-01

Secondary exposure to community violence, defined as witnessing or hearing violence in the community, has the potential to profoundly impact long-term development, health, happiness, and security. While research has explored pathways to community violence exposure at the individual, family, and neighborhood levels, prior work has largely neglected situational factors conducive to secondary violence exposure. The present study evaluates "unstructured socializing with peers in the absence of authority figures" as a situational process that has implications for secondary exposure to violence. Results indicate that a measure of unstructured socializing was significantly associated with exposure to violence, net of an array of theoretically relevant covariates of violence exposure. Moreover, the relationships between exposure to violence and three of the most well-established correlates of violence exposure in the literature-age, male, and prior violence-were mediated to varying degrees by unstructured socializing. The results suggest a more nuanced approach to the study of secondary violence exposure that expands the focus of attention beyond individual and neighborhood background factors to include situational opportunities presented by patterns of everyday activities. © The Author(s) 2013.

Teachers' Challenges, Strategies, and Support Needs in Schools Affected by Community Violence: A Qualitative Study

ERIC Educational Resources Information Center

Maring, Elisabeth F.; Koblinsky, Sally A.

2013-01-01

Background: Exposure to community violence compromises teacher effectiveness, student learning, and socioemotional well-being. This study examined the challenges, strategies, and support needs of teachers in urban schools affected by high levels of community violence. Methods: Twenty teachers from 3 urban middle schools with predominantly…

Sex-Specific Associations between Umbilical Cord Blood Testosterone Levels and Language Delay in Early Childhood

ERIC Educational Resources Information Center

Whitehouse, Andrew J. O.; Mattes, Eugen; Maybery, Murray T.; Sawyer, Michael G.; Jacoby, Peter; Keelan, Jeffrey A.; Hickey, Martha

2012-01-01

Background: Preliminary evidence suggests that prenatal testosterone exposure may be associated with language delay. However, no study has examined a large sample of children at multiple time-points. Methods: Umbilical cord blood samples were obtained at 861 births and analysed for bioavailable testosterone (BioT) concentrations. When…

Exploration of the Rapid Effects of Personal Fine Particulate Matter Exposure on Hemodynamics and Vascular Function during the Same Day

EPA Science Inventory

Background: Levels of fine particulate matter [≤ 2.5 μm in aerodynamic diameter (PM_2.5)] are associated with alterations in arterial hemodynamics and vascular function. However, the characteristics of the same-day exposure–response relationships remain unclear. Object...

Serum Levels of Dioxin and Dioxin-Like Compounds in Women Living in a Highly Industrialized Area of West Virginia

EPA Science Inventory

Historical releases of dioxin and dioxin-like constituents with subsequent impacts to environmental media in the Kanawha River Valley (KV) of West Virginia have been well documented. This study evaluated the impact of potentially high background dioxin exposure to body burdens i...

The glutathione-S-transferase mu 1 (GSTM1) null genotype and increased neutrophil response to low-level ozone (0.06 ppm).

EPA Science Inventory

Background: Exposure of healthy young adults to 03 modulates immune cell biology in the airways and causes a significant increase in neutrophilic inflammation which can vary considerably in magnitude across individuals. The GSTM1null genotype modulates Oj-induced inflammation, bu...

Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps associated with uranium exploration and mining, Browns Hole, Utah

USGS Publications Warehouse

Marston, Thomas M.; Beisner, Kimberly R.; Naftz, David L.; Snyder, Terry

2012-01-01

During August of 2008, 35 solid-phase samples were collected from abandoned uranium waste dumps, undisturbed geologic background sites, and adjacent streambeds in Browns Hole in southeastern Utah. The objectives of this sampling program were (1) to assess impacts on human health due to exposure to radium, uranium, and thorium during recreational activities on and around uranium waste dumps on Bureau of Land Management lands; (2) to compare concentrations of trace elements associated with mine waste dumps to natural background concentrations; (3) to assess the nonpoint source chemical loading potential to ephemeral and perennial watersheds from uranium waste dumps; and (4) to assess contamination from waste dumps to the local perennial stream water in Muleshoe Creek. Uranium waste dump samples were collected using solid-phase sampling protocols. Solid samples were digested and analyzed for major and trace elements. Analytical values for radium and uranium in digested samples were compared to multiple soil screening levels developed from annual dosage calculations in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act's minimum cleanup guidelines for uranium waste sites. Three occupancy durations for sites were considered: 4.6 days per year, 7.0 days per year, and 14.0 days per year. None of the sites exceeded the radium soil screening level of 96 picocuries per gram, corresponding to a 4.6 days per year exposure. Two sites exceeded the radium soil screening level of 66 picocuries per gram, corresponding to a 7.0 days per year exposure. Seven sites exceeded the radium soil screening level of 33 picocuries per gram, corresponding to a 14.0 days per year exposure. A perennial stream that flows next to the toe of a uranium waste dump was sampled, analyzed for major and trace elements, and compared with existing aquatic-life and drinking-water-quality standards. None of the water-quality standards were exceeded in the stream samples.

Symptoms in Response to Controlled Diesel Exhaust More Closely Reflect Exposure Perception Than True Exposure

PubMed Central

Carlsten, Chris; Oron, Assaf P.; Curtiss, Heidi; Jarvis, Sara; Daniell, William; Kaufman, Joel D.

2013-01-01

Background Diesel exhaust (DE) exposures are very common, yet exposure-related symptoms haven’t been rigorously examined. Objective Describe symptomatic responses to freshly generated and diluted DE and filtered air (FA) in a controlled human exposure setting; assess whether such responses are altered by perception of exposure. Methods 43 subjects participated within three double-blind crossover experiments to order-randomized DE exposure levels (FA and DE calibrated at 100 and/or 200 micrograms/m3 particulate matter of diameter less than 2.5 microns), and completed questionnaires regarding symptoms and dose perception. Results For a given symptom cluster, the majority of those exposed to moderate concentrations of diesel exhaust do not report such symptoms. The most commonly reported symptom cluster was of the nose (29%). Blinding to exposure is generally effective. Perceived exposure, rather than true exposure, is the dominant modifier of symptom reporting. Conclusion Controlled human exposure to moderate-dose diesel exhaust is associated with a range of mild symptoms, though the majority of individuals will not experience any given symptom. Blinding to DE exposure is generally effective. Perceived DE exposure, rather than true DE exposure, is the dominant modifier of symptom reporting. PMID:24358296

Estimation of Particulate Mass and Manganese Exposure Levels among Welders

PubMed Central

Hobson, Angela; Seixas, Noah; Sterling, David; Racette, Brad A.

2011-01-01

Background: Welders are frequently exposed to Manganese (Mn), which may increase the risk of neurological impairment. Historical exposure estimates for welding-exposed workers are needed for epidemiological studies evaluating the relationship between welding and neurological or other health outcomes. The objective of this study was to develop and validate a multivariate model to estimate quantitative levels of welding fume exposures based on welding particulate mass and Mn concentrations reported in the published literature. Methods: Articles that described welding particulate and Mn exposures during field welding activities were identified through a comprehensive literature search. Summary measures of exposure and related determinants such as year of sampling, welding process performed, type of ventilation used, degree of enclosure, base metal, and location of sampling filter were extracted from each article. The natural log of the reported arithmetic mean exposure level was used as the dependent variable in model building, while the independent variables included the exposure determinants. Cross-validation was performed to aid in model selection and to evaluate the generalizability of the models. Results: A total of 33 particulate and 27 Mn means were included in the regression analysis. The final model explained 76% of the variability in the mean exposures and included welding process and degree of enclosure as predictors. There was very little change in the explained variability and root mean squared error between the final model and its cross-validation model indicating the final model is robust given the available data. Conclusions: This model may be improved with more detailed exposure determinants; however, the relatively large amount of variance explained by the final model along with the positive generalizability results of the cross-validation increases the confidence that the estimates derived from this model can be used for estimating welder exposures in absence of individual measurement data. PMID:20870928

Contaminant exposure of willets feeding in agricultural drainages of the lower Rio Grande valley of south Texas USA

USGS Publications Warehouse

Custer, T.W.; Mitchell, C.A.

1991-01-01

Willets (Catoptrophorus semipalmatus) were collected in June and August 1986 at the outlets of two agricultural drainages into the Lower Languna Madre of south Texas and at two other Texas coastal sites. Mean liver concentrations of arsenic was higher in August than June. Over 20% of the livers had arsenic concentrations elevated above a suggested background level of 5.0 ppm dry weight (DW), but concentrations (maximum 15 ppm) were below those associated with acute toxicity. Selenium concentration in livers varied from 2.3 to 8.3 ppm DW for all locations and represented background levels. Mercury concentrations in liver for all locations (mean = 2.0 to 3.4, maximum 17 ppm DW) were below those associated with avian mortality and similar to levels found in other estuarine/marine birds. DDE in carcasses was higher in adults (mean = 1.0 ppm wet weight) than juveniles (0.2 ppm), and higher in August (1.0 ppm) than June (0.5 ppm); however, DDE concentrations were generally at background levels. Based on brain cholinesterase activity, willets were not recently exposed to organophosphate pesticides.

Surface alpha backgrounds from plate-out of radon progeny

NASA Astrophysics Data System (ADS)

Perumpilly, Gopakumar; Guiseppe, Vincente

2012-03-01

Low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly Rn-222) and its subsequent daughters present in an experiment are potential backgrounds, more troublesome is the deposition of radon daughters on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by daughters supported by the long half life (22 y) of Pb-210 on sensitive locations of a detector. We have developed a model of the radon progeny implantation using Geant4 simulations based on the low energy nuclear recoil process. We explore the alpha decays from implanted progeny on a Ge crystal as potential backgrounds for a neutrinoless double-beta decay experiment. Results of the simulations validated with alpha spectrum measurement of plate-out samples will be presented.

Gulf War Illnesses: Understanding of Health Effects From Depleted Uranium Evolving But Safety Training Needed

DTIC Science & Technology

2000-03-01

against enemy munitions. Depleted uranium is a low- level radioactive heavy metal , and concerns have surfaced about whether exposure to it could be a...radioactive heavy metal , the potential for health effects are twofold: effects from radiation and effects from chemical toxicity. Two recent expert...depleted uranium safety training. Background Depleted uranium (DU), a low-level radioactive heavy metal , is a by- product of the process used to

Health Implications of PAH Release from Coated Cast Iron Drinking Water Distribution Systems in the Netherlands

PubMed Central

van de Ven, Bianca M.; de Jongh, Cindy M.

2013-01-01

Background: Coal tar and bitumen have been historically used to coat the insides of cast iron drinking water mains. Polycyclic aromatic hydrocarbons (PAHs) may leach from these coatings into the drinking water and form a potential health risk for humans. Objective: We estimated the potential human cancer risk from PAHs in coated cast iron water mains. Method: In a Dutch nationwide study, we collected drinking water samples at 120 locations over a period of 17 days under various operational conditions, such as undisturbed operation, during flushing of pipes, and after a mains repair, and analyzed these samples for PAHs. We then estimated the health risk associated with an exposure scenario over a lifetime. Results: During flushing, PAH levels frequently exceeded drinking water quality standards; after flushing, these levels dropped rapidly. After the repair of cast iron water mains, PAH levels exceeded the drinking water standards for up to 40 days in some locations. Conclusions: The estimated margin of exposure for PAH exposure through drinking water was > 10,000 for all 120 measurement locations, which suggests that PAH exposure through drinking water is of low concern for consumer health. However, factors that differ among water systems, such as the use of chlorination for disinfection, may influence PAH levels in other locations. PMID:23425894

Baseline blood Pb levels of black-necked stilts on the upper Texas coast

USGS Publications Warehouse

Riecke, Thomas V.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.

2015-01-01

There are no known biological requirements for lead (Pb), and elevated Pb levels in birds can cause a variety of sub-lethal effects and mortality. Historic and current levels of Pb in mottled ducks (Anas fulvigula) suggest that environmental sources of Pb remain available on the upper Texas coast. Because of potential risks of Pb exposure among coexisting marsh birds, black-necked stilt (Himantopus mexicanus) blood Pb concentrations were measured during the breeding season. Almost 80 % (n = 120) of 152 sampled stilts exceeded the background threshold (>20 μg/dL) for Pb exposure. However, blood Pb concentrations did not vary by age or gender, and toxic or potentially lethal concentrations were rare (<5 %). Consistent, low-level blood Pb concentrations of black-necked stilts in this study suggest the presence of readily bioavailable sources of Pb, although potential impacts on local stilt populations remain unclear.

The Mere Exposure Effect in the Domain of Haptics

PubMed Central

Jakesch, Martina; Carbon, Claus-Christian

2012-01-01

Background Zajonc showed that the attitude towards stimuli that one had been previously exposed to is more positive than towards novel stimuli. This mere exposure effect (MEE) has been tested extensively using various visual stimuli. Research on the MEE is sparse, however, for other sensory modalities. Methodology/Principal Findings We used objects of two material categories (stone and wood) and two complexity levels (simple and complex) to test the influence of exposure frequency (F0 = novel stimuli, F2 = stimuli exposed twice, F10 = stimuli exposed ten times) under two sensory modalities (haptics only and haptics & vision). Effects of exposure frequency were found for high complex stimuli with significantly increasing liking from F0 to F2 and F10, but only for the stone category. Analysis of “Need for Touch” data showed the MEE in participants with high need for touch, which suggests different sensitivity or saturation levels of MEE. Conclusions/Significance This different sensitivity or saturation levels might also reflect the effects of expertise on the haptic evaluation of objects. It seems that haptic and cross-modal MEEs are influenced by factors similar to those in the visual domain indicating a common cognitive basis. PMID:22347451

IgG responses to the gSG6-P1 salivary peptide for evaluating human exposure to Anopheles bites in urban areas of Dakar region, Sénégal

PubMed Central

2012-01-01

Background Urban malaria can be a serious public health problem in Africa. Human-landing catches of mosquitoes, a standard entomological method to assess human exposure to malaria vector bites, can lack sensitivity in areas where exposure is low. A simple and highly sensitive tool could be a complementary indicator for evaluating malaria exposure in such epidemiological contexts. The human antibody response to the specific Anopheles gSG6-P1 salivary peptide have been described as an adequate tool biomarker for a reliable assessment of human exposure level to Anopheles bites. The aim of this study was to use this biomarker to evaluate the human exposure to Anopheles mosquito bites in urban settings of Dakar (Senegal), one of the largest cities in West Africa, where Anopheles biting rates and malaria transmission are supposed to be low. Methods One cross-sectional study concerning 1,010 (505 households) children (n = 505) and adults (n = 505) living in 16 districts of downtown Dakar and its suburbs was performed from October to December 2008. The IgG responses to gSG6-P1 peptide have been assessed and compared to entomological data obtained in or near the same district. Results Considerable individual variations in anti-gSG6-P1 IgG levels were observed between and within districts. In spite of this individual heterogeneity, the median level of specific IgG and the percentage of immune responders differed significantly between districts. A positive and significant association was observed between the exposure levels to Anopheles gambiae bites, estimated by classical entomological methods, and the median IgG levels or the percentage of immune responders measuring the contact between human populations and Anopheles mosquitoes. Interestingly, immunological parameters seemed to better discriminate the exposure level to Anopheles bites between different exposure groups of districts. Conclusions Specific human IgG responses to gSG6-P1 peptide biomarker represent, at the population and individual levels, a credible new alternative tool to assess accurately the heterogeneity of exposure level to Anopheles bites and malaria risk in low urban transmission areas. The development of such biomarker tool would be particularly relevant for mapping and monitoring malaria risk and for measuring the efficiency of vector control strategies in these specific settings. PMID:22424570

A review on natural background radiation

PubMed Central

Shahbazi-Gahrouei, Daryoush; Gholami, Mehrdad; Setayandeh, Samaneh

2013-01-01

The world is naturally radioactive and approximately 82% of human-absorbed radiation doses, which are out of control, arise from natural sources such as cosmic, terrestrial, and exposure from inhalation or intake radiation sources. In recent years, several international studies have been carried out, which have reported different values regarding the effect of background radiation on human health. Gamma radiation emitted from natural sources (background radiation) is largely due to primordial radionuclides, mainly 232Th and 238U series, and their decay products, as well as 40K, which exist at trace levels in the earth's crust. Their concentrations in soil, sands, and rocks depend on the local geology of each region in the world. Naturally occurring radioactive materials generally contain terrestrial-origin radionuclides, left over since the creation of the earth. In addition, the existence of some springs and quarries increases the dose rate of background radiation in some regions that are known as high level background radiation regions. The type of building materials used in houses can also affect the dose rate of background radiations. The present review article was carried out to consider all of the natural radiations, including cosmic, terrestrial, and food radiation. PMID:24223380

Exposure to Low Levels of Lead in Utero and Umbilical Cord Blood DNA Methylation in Project Viva: An Epigenome-Wide Association Study

PubMed Central

Hivert, Marie-France; Cardenas, Andres; Zhong, Jia; Rifas-Shiman, Sheryl L.; Agha, Golareh; Colicino, Elena; Just, Allan C.; Amarasiriwardena, Chitra; Lin, Xihong; Litonjua, Augusto A.; DeMeo, Dawn L.; Gillman, Matthew W.; Wright, Robert O.; Oken, Emily

2017-01-01

Background: Early-life exposure to lead is associated with deficits in neurodevelopment and with hematopoietic system toxicity. DNA methylation may be one of the underlying mechanisms for the adverse effects of prenatal lead on the offspring, but epigenome-wide methylation data for low levels of prenatal lead exposure are lacking. Objectives: We investigated the association between prenatal maternal lead exposure and epigenome-wide DNA methylation in umbilical cord blood nucleated cells in Project Viva, a prospective U.S.-based prebirth cohort with relatively low levels of lead exposure. Methods: Among 268 mother–infant pairs, we measured lead concentrations in red blood cells (RBC) from prenatal maternal blood samples, and using HumanMethylation450 Bead Chips, we measured genome-wide methylation levels at 482,397 CpG loci in umbilical cord blood and retained 394,460 loci after quality control. After adjustment for batch effects, cell types, and covariates, we used robust linear regression models to examine associations of prenatal lead exposure with DNA methylation in cord blood at epigenome-wide significance level [false discovery rate (FDR)<0.05]. Results: The mean [standard deviation (SD)] maternal RBC lead level was 1.22 (0.63) μg/dL. CpG cg10773601 showed an epigenome-wide significant negative association with prenatal lead exposure (−1.4% per doubling increase in lead exposure; p=2.3×10−7) and was annotated to C-Type Lectin Domain Family 11, Member A (CLEC11A), which functions as a growth factor for primitive hematopoietic progenitor cells. In sex-specific analyses, we identified more CpGs with FDR<0.05 among female infants (n=38) than among male infants (n=2). One CpG (cg24637308), which showed a strong negative association with prenatal lead exposure among female infants (−4.3% per doubling increase in lead exposure; p=1.1×10−06), was annotated to Dynein Heavy Chain Domain 1 gene (DNHD1) which is highly expressed in human brain. Interestingly, there were strong correlations between blood and brain methylation for CpG (cg24637308) based on another independent set of samples with a high proportion of female participants. Conclusion: Prenatal low-level lead exposure was associated with newborn DNA methylation, particularly in female infants. https://doi.org/10.1289/EHP1246 PMID:28858830

Below-Background Ionizing Radiation as an Environmental Cue for Bacteria

DOE PAGES

Castillo, Hugo; Smith, Geoffrey B.

2017-02-14

All organisms on earth grow under the influence of a natural and relatively constant dose of ionizing radiation referred to as background radiation, and so cells have different mechanisms to prevent the accumulation of damage caused by its different components. However, current knowledge of the deleterious effects of radiation on cells is based on the exposure to acute and high or to chronic, above background doses of radiation and therefore is not appropriate to explain the cellular and biochemical mechanisms that cells employ to sense and respond to chronic below-background levels. Studies at below-background radiation doses can provide insight intomore » the biological role of radiation, as suggested by several examples of what appears to be a stress response in cells grown at doses that range from 10 to 79 times lower than background. Here, we discuss some of the technical constraints to shield cells from radiation to below-background levels, as well as different approaches used to detect and measure responses to such unusual environmental conditions. Then, we present data from Shewanella oneidensis and Deinococcus radiodurans experiments that show how two taxonomically distant bacterial species sense and respond to unnaturally low levels of radiation. Finally, in brief, we grew S. oneidensis and D. radiodurans in liquid culture at dose rates of 72.05 (control) and 0.91 (treatment) nGy hr -1 (including radon) for up to 72 h and measured cell density and the expression of stress-related genes. Our results suggest that a stress response is triggered in the absence of normal levels of radiation.« less

Below-Background Ionizing Radiation as an Environmental Cue for Bacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castillo, Hugo; Smith, Geoffrey B.

All organisms on earth grow under the influence of a natural and relatively constant dose of ionizing radiation referred to as background radiation, and so cells have different mechanisms to prevent the accumulation of damage caused by its different components. However, current knowledge of the deleterious effects of radiation on cells is based on the exposure to acute and high or to chronic, above background doses of radiation and therefore is not appropriate to explain the cellular and biochemical mechanisms that cells employ to sense and respond to chronic below-background levels. Studies at below-background radiation doses can provide insight intomore » the biological role of radiation, as suggested by several examples of what appears to be a stress response in cells grown at doses that range from 10 to 79 times lower than background. Here, we discuss some of the technical constraints to shield cells from radiation to below-background levels, as well as different approaches used to detect and measure responses to such unusual environmental conditions. Then, we present data from Shewanella oneidensis and Deinococcus radiodurans experiments that show how two taxonomically distant bacterial species sense and respond to unnaturally low levels of radiation. Finally, in brief, we grew S. oneidensis and D. radiodurans in liquid culture at dose rates of 72.05 (control) and 0.91 (treatment) nGy hr -1 (including radon) for up to 72 h and measured cell density and the expression of stress-related genes. Our results suggest that a stress response is triggered in the absence of normal levels of radiation.« less

Operating room sound level hazards for patients and physicians.

PubMed

Fritsch, Michael H; Chacko, Chris E; Patterson, Emily B

2010-07-01

Exposure to certain new surgical instruments and operating room devices during procedures could cause hearing damage to patients and personnel. Surgical instruments and related equipment generate significant sound levels during routine usage. Both patients and physicians are exposed to these levels during the operative cases, many of which can last for hours. The noise loads during cases are cumulative. Occupational Safety and Health Administration (OSHA) and National Institute for Occupational Safety and Health (NIOSH) standards are inconsistent in their appraisals of potential damage. Implications of the newer power instruments are not widely recognized. Bruel and Kjaer sound meter spectral recordings for 20 major instruments from 5 surgical specialties were obtained at the ear levels for the patient and the surgeon between 32 and 20 kHz. Routinely used instruments generated sound levels as high as 131 dB. Patient and operator exposures differed. There were unilateral dominant exposures. Many instruments had levels that became hazardous well within the length of an average surgical procedure. The OSHA and NIOSH systems gave contradicting results when applied to individual instruments and types of cases. Background noise, especially in its intermittent form, was also of significant nature. Some patients and personnel have additional predisposing physiologic factors. Instrument noise levels for average length surgical cases may exceed OSHA and NIOSH recommendations for hearing safety. Specialties such as Otolaryngology, Orthopedics, and Neurosurgery use instruments that regularly exceed limits. General operating room noise also contributes to overall personnel exposures. Innovative countermeasures are suggested.

Perfluorochemical (PFC) Exposure in Children: Associations with Impaired Response Inhibition

PubMed Central

Gump, Brooks B.; Wu, Qian; Dumas, Amy K.; Kannan, Kurunthachalam

2011-01-01

Background Perfluorinated chemicals (PFCs) have been used widely in consumer products since the 1950s and are currently found at detectable levels in the blood of humans and animals across the globe. In stark contrast to this widespread exposure to PFCs, there is relatively little research on potential adverse health effects of exposure to these chemicals. Objectives We performed this cross-sectional study to determine if specific blood PFC levels are associated with impaired response inhibition in children. Methods Blood levels of 11 PFCs were measured in children (N = 83) and 6 PFCs: perfluorooctane sulfonate (PFOS), perfluorohexane sulfate (PFHxS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorooctanesulfonamide (PFOSA), and perfluorodecanoic acid (PFDA) – were found at detectable levels in most children (87.5% or greater had detectable levels). These levels were analyzed in relation to the differential reinforcement of low rates of responding (DRL) task. This task rewards delays between responses (i.e., longer inter-response times; IRTs) and therefore constitutes a measure of response inhibition. Results Higher levels of blood PFOS, PFNA, PFDA, PFHxS, and PFOSA were associated with significantly shorter IRTs during the DRL task. The magnitude of these associations was such that IRTs during the task decreased by 29–34% for every 1 SD increase in the corresponding blood PFC. Conclusions This study suggests an association between PFC exposure and children’s impulsivity. Although intriguing, there is a need for further investigation and replication with a larger sample of children. PMID:21682250

Intergenerational preferences for radio loudness during automobile driving.

PubMed

Hanser, Frederick Howard Bateman; Adjei Boakye, Eric; Mikulec, Anthony Alan

2017-07-01

The comparative contribution to human noise exposure from the vehicular radio is unknown, as are the radio volume preferences of different generations when driving an automobile. A single vehicle was used to measure radio listening level in decibels of three generations (age 16-17 years, age 32-50 years, and age 51-73 years) in various conditions, ranging from engine off with windows closed to 60 miles per hour (mph) with windows open. No differences in radio loudness based on the sex of the driver were found. Statistically significant differences were identified in preferred signal to noise ratio among multiple vehicular paradigms, with the youngest generation preferring the largest signal to noise ratio in conditions with low background noise. The youngest generation favored the largest signal to noise ratio (radio level above background noise), a preference which waned with increasing background noise. Copyright © 2017 Elsevier B.V. All rights reserved.

Association between type 2 diabetes and chronic arsenic exposure in drinking water: A cross sectional study in Bangladesh

PubMed Central

2012-01-01

Background Chronic exposure to high level of inorganic arsenic in drinking water has been associated with Type 2 Diabetes (T2D). Most research has been ecological in nature and has focused on high levels of arsenic exposure with few studies directly measuring arsenic levels in drinking water as an index of arsenic exposure. The effect of low to moderate levels of arsenic exposure on diabetes risk is largely unknown thus our study is adding further knowledge over previous works. Methods This cross sectional study was conducted in 1004 consenting women and men from 1682 eligible participants yielding a participation rate of 60%. These participants are aged >30 years and were living in Bangladesh and had continuously consumed arsenic-contaminated drinking water for at least 6 months. T2D cases were diagnosed using glucometer following the new diagnostic criteria (Fasting Blood Glucose > 126 mg/dl) from the WHO guideline (WHO 2006), or a self-reported physician diagnosis of type 2 diabetes. Association between T2D and chronic arsenic exposure was estimated by multiple logistic regression with adjustment for age, sex, education, Body Mass Index (BMI) and family history of T2D. Results A total of 1004 individuals participated in the study. The prevalence of T2D was 9% (95% CI 7-11%). After adjustment for diabetes risk factors, an increased risk of type 2 diabetes was observed for arsenic exposure over 50 μg/L with those in the highest category having almost double the risk of type 2 diabetes (OR=1.9 ; 95% CI 1.1-3.5). For most levels of arsenic exposure, the risk estimates are higher with longer exposure; a dose–response pattern was also observed. Conclusions These findings suggest an association between chronic arsenic exposure through drinking water and T2D. Risks are generally higher with longer duration of arsenic exposure. The risk of T2D is highest among those who were exposed to the highest concentration of arsenic for more than 10 years. PMID:22676249

Individual-level exposure to disaster, neighborhood environmental characteristics, and their independent and combined associations with depressive symptoms in women.

PubMed

Gaston, Symielle A; Volaufova, Julia; Peters, Edward S; Ferguson, Tekeda F; Robinson, William T; Nugent, Nicole; Trapido, Edward J; Rung, Ariane L

2017-09-01

The severity of the stress response to experiencing disaster depends on individual exposure and background stress prior to the event. To date, there is limited research on the interaction between neighborhood environmental stress and experiencing an oil spill, and their effects on depression. The objective of the current study was to assess if the association between exposure to the Deepwater Horizon Oil Spill (DHOS) and depressive symptoms varied by neighborhood characteristics. US Census data (2010) and longitudinal data collected in two waves (2012-2014 and 2014-2016) from female residents [N = 889 (Wave I), 737 (Wave II)] of an area highly affected by the DHOS were analyzed. Multilevel and individual-level negative binomial regressions were performed to estimate associations with depressive symptoms in both waves. An interaction term was included to estimate effect modification of the association between DHOS exposure and depressive symptoms by neighborhood characteristics. Generalized estimating equations were applied to the negative binomial regression testing longitudinal associations. Census tract-level neighborhood characteristics were not associated with depressive symptoms. Exposure to the DHOS and neighborhood physical disorder were associated with depressive symptoms cross-sectionally. There was no evidence of effect modification; however, physical/environmental exposure to the DHOS was associated with increased depressive symptoms only among women living in areas with physical disorder. Exposure to the DHOS remained associated with depressive symptoms over time. Findings support the enduring consequences of disaster exposure on depressive symptoms in women and identify potential targets for post-disaster intervention based on residential characteristics.

Blood lead exposure concentrations in mottled ducks (Anas fulvigula) on the upper Texas coast

USGS Publications Warehouse

McDowell, Stephen K.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.; Hung, I-Kuai

2015-01-01

The mottled duck (Anas fulvigula) is a non-migratory waterfowl species dependent upon coastal marsh systems, including those on the Texas Chenier Plain National Wildlife Refuge (NWR) Complex, and considered a regional indicator species of marsh habitat quality. Research from the early 1970s, 1990s, and early-2000s indicated that mottled ducks continued to exhibit elevated wing-bone lead (Pb) concentrations, decades after implementation of non-toxic shot regulations. However, wing-bone concentrations reflect lifetime accumulation of Pb, whereas blood Pb concentrations reflect more recent exposure. To identify current potentially relevant temporal windows of Pb exposure, we collected 260 blood samples from mottled ducks during summer (n=124) and winter (n=136) from 2010–2012 on the Texas Chenier Plain NWR Complex. We quantified baseline blood Pb concentrations for all ages of mottled ducks, and hypothesized that blood lead concentrations would remain elevated above background levels (200 µg L–1) despite the 1983 and 1991 lead shot bans. Blood Pb concentrations ranged from below detection limits to >12,000 µg L–1, where >200 µg L–1 was associated with exposure levels above background concentrations. Male mottled ducks had the greatest blood Pb concentrations (30 times greater than females) with concentrations greater during winter than summer. Likewise, the proportion of exposed (>200 µg L–1) females increased from 14%–47% from summer to winter, respectively. Regardless of sex, adult mottled duck blood Pb concentrations were five times greater than juveniles, particularly during winter. We identified five plausible models that influenced blood Pb levels where year, site, and interactions among age*sex*season and between age*season were included in the top-ranked models. Frequency of exposure was greatest during winter, increasing from 12% in summer to 55% in winter, indicating that a temporal exposure window to environmental Pb exists between nesting and hunting seasons. Blood Pb concentrations remain elevated in mottled ducks despite Pb shot bans enacted >25 years prior to this study. If Pb levels in mottled ducks becomes a conservation concern, regional monitoring of blood Pb concentrations would be appropriate with a focus upon elucidating potential reasons for the variation among age and sex groups. Finally, identifying potentially available sources of environmental Pb may be key to minimizing this apparently persistent threat to mottled ducks on the upper Texas coast.

Concentrations and spatial patterns of organic contaminants in tree swallow (Tachycineta bicolor) eggs at United States and binational Great Lakes Areas of Concern, 2010–2015

USGS Publications Warehouse

Custer, Christine M.; Custer, Thomas W.; Dummer, Paul; Goldberg, Diana R.; Franson, J. Christian

2016-01-01

Tree swallows, Tachycineta bicolor, were sampled across the Great Lakes basin in 2010 through 2015 to provide a system-wide assessment of current exposure to organic contaminants. The results provide information identified as critical by regulators to assess the “bird or animal deformity or reproductive problems” beneficial use impairment. Eggs were collected from 69 sites across all 5 Great Lakes, including 27 Areas of Concern (AOCs), some with multiple sites, and 10 sites not listed as an AOC. Concentrations of organic contaminants in eggs were quantified and compared with background and reproductive effect thresholds. Approximately 30% of AOCs had geometric mean concentrations of total polychlorinated biphenyls (PCBs) at or below average background exposure (0.34 μg/g wet wt). Exposure to polybrominated diphenyl ethers (PBDEs) was minimal, and only 3 of 27 AOCs and 1 non-AOC had geometric mean concentrations that exceeded background for tree swallows (96 ng/g wet wt). Concentrations of both PCBs and PBDEs were 10 to 20 times below the lower limit associated with impaired hatching success. In contrast, geometric mean concentrations of polychlorinated dibenzo-p-dioxin and furan (PCDD-F) toxic equivalents (TEQs) at the Saginaw River and Bay AOC and Midland, Michigan, USA (a non-AOC site), exceeded the lower limit for hatching effects (181 pg/g PCDD-F TEQs). The rest of the sites had geometric mean concentrations of PCDD-F TEQs below background levels (87 pg/g PCDD-F TEQs). Other organic contaminants, including p,p′-dichlorodiphenyldichloroethylene, mirex, heptachlor, and chlordane, were at or below background or adverse effect concentrations.

The U.S. Food and Drug Administration Risk Assessment on Lead in Women’s and Children’s Vitamins Is Based on Outdated Assumptions

PubMed Central

Miodovnik, Amir; Landrigan, Philip J.

2009-01-01

Background Following a recent report of lead in certain commercial vitamin products, the U.S. Food and Drug Administration (FDA) conducted a nationwide survey to determine the Pb content in 324 multivitamin/mineral products labeled for use by women and children. The FDA compared estimated Pb exposures from each product with safe/tolerable exposure levels, termed provisional total tolerable intake (PTTI) levels, previously developed for at-risk population groups in 1992. Objective We investigated the FDA’s conclusions that Pb concentrations in all vitamin products examined do not pose a hazard to health because they are below the PTTI levels for all groups considered. Discussion For their initial estimations of PTTI levels, the FDA used a blood lead level (BLL) of 10 μg/dL as the threshold for adverse effects in children and in pregnant or lactating women. Studies have repeatedly linked chronic exposure to BLLs < 10 μg/dL with impairments in cognitive function and behavior in young children despite the absence of overt signs of toxicity. The FDA analysis also omitted any consideration of nonfood sources of Pb exposure, which is inconsistent with our current understanding of how most children develop elevated BLLs. Conclusion We feel that based on these oversights, the FDA’s conclusions are unduly reassuring and that reconsideration of their current recommendations appears warranted. PMID:19654907

Control of workers’ exposure to xylene in a pesticide production factory

PubMed Central

Mohammadyan, M; Baharfar, Y

2015-01-01

Background: Acute and chronic exposure to xylene can result in a range of negative health effects. However, xylene is widely used and emitted in the air of workplaces. Objectives: To evaluate xylene vapor concentrations to guide the design and evaluation of a local exhaust ventilation (LEV) system to reduce exposure in a pesticide production factory. Method: A real time volatile organic compound (VOC) monitor was used to determine the workers’ time-weighted average (TWA) exposure. A LEV system was designed, and then, workers’ exposure to xylene vapor was evaluated. Results: We found that worker’s exposure to xylene (4.7±5.5 ppm) was lower than the standards recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) and the Occupational safety and health administration (OSHA). Despite the low TWA exposures, the short-term exposures for some workers were higher than STEL levels. Three canopy hoods were designed and installed with capture velocities of 0.508 m second−1 and duct velocity of 10.16 m second−1. Conclusion: We found that an exhaust ventilation system had a significantly reduced occupational exposure to xylene vapor. PMID:25487643

Osteopontin, asbestos exposure and pleural plaques: a cross-sectional study

PubMed Central

2011-01-01

Background Osteopontin (OPN) is a plasma protein/cytokine produced in excess in several malignancies. In a recent study OPN was reported as being related to the duration of asbestos exposure and presence of benign asbestos-related diseases; however, it was unclear whether this protein was an indicator of exposure or effect. Methods In 193 workers, 50 with pleural plaques (PP), in whom different indicators of past asbestos exposure were estimated, OPN plasma levels were assessed using commercial quantitative sandwich enzyme immunoassays according to the manufacturer's instructions. Results Osteopontin increased with increasing age and several aspects of asbestos exposure, without differences related to the presence of pleural plaques. At multivariable regression analysis, the explanatory variables with a significant independent influence on OPN were length of exposure (positive correlation) and time elapsed since last exposure (positive correlation). Conclusions Since asbestos in lung tissue tends to wane over time, OPN should decrease (rather than increase) with time since last exposure. Therefore, OPN cannot be a reliable biomarker of exposure nor effect (presence of pleural plaques). PMID:21477289

Radiation protection aspects of the cosmic radiation exposure of aircraft crew.

PubMed

Bartlett, D T

2004-01-01

Aircraft crew and frequent flyers are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, the aircraft structure and its contents. Following recommendations of the International Commission on Radiological Protection in Publication 60, the European Union introduced a revised Basic Safety Standards Directive, which included exposure to natural sources of ionising radiation, including cosmic radiation, as occupational exposure. The revised Directive has been incorporated into laws and regulations in the European Union Member States. Where the assessment of the occupational exposure of aircraft crew is necessary, the preferred approach to monitoring is by the recording of staff flying times and calculated route doses. Route doses are to be validated by measurements. This paper gives the general background, and considers the radiation protection aspects of the cosmic radiation exposure of aircraft crew, with the focus on the situation in Europe.

Children's cognition and aircraft noise exposure at home--the West London Schools Study.

PubMed

Matsui, T; Stansfeld, S; Haines, M; Head, J

2004-01-01

The association of aircraft noise exposure with cognitive performance was examined by means of a cross-sectional field survey. Two hundred thirty six children attending 10 primary schools around Heathrow Airport in west London were tested on reading comprehension, immediate/delayed recall and sustained attention. In order to obtain the information about their background, a questionnaire was delivered to the parents and 163 answers were collected. Logistic regression models were used to assess performance on the cognitive tests in relation to aircraft noise exposure at home and possible individual and school level confounding factors. A significant dose-response relationship was found between aircraft noise exposure at home and performance on memory tests of immediate/delayed recall. However there was no strong association with the other cognitive outcomes. These results suggest that aircraft noise exposure at home may affect children's memory.

Milestones on the social accountability journey: Family medicine practice locations of Northern Ontario School of Medicine graduates.

PubMed

Hogenbirk, John C; Timony, Patrick E; French, Margaret G; Strasser, Roger; Pong, Raymond W; Cervin, Catherine; Graves, Lisa

2016-03-01

To assess the effect of different levels of exposure to the Northern Ontario School of Medicine's (NOSM's) distributed medical education programs in northern Ontario on FPs' practice locations. Cross-sectional design using longitudinal survey and administrative data. Canada. All 131 Canadian medical graduates who completed FP training in 2011 to 2013 and who completed their undergraduate (UG) medical degree or postgraduate (PG) residency training or both at NOSM. Exposure to NOSM's medical education program at the UG (n = 49) or PG (n = 31) level or both (n = 51). Primary practice location in September of 2014. Approximately 16% (21 of 129) of FPs were practising in rural northern Ontario, 45% (58 of 129) in urban northern Ontario, and 5% (7 of 129) in rural southern Ontario. Logistic regression found that more rural Canadian background years predicted rural practice in northern Ontario or Ontario, with odds ratios of 1.16 and 1.12, respectively. Northern Canadian background, sex, marital status, and having children did not predict practice location. Completing both UG and PG training at NOSM predicted practising in rural and northern Ontario locations with odds ratios of 4.06 to 48.62. Approximately 61% (79 of 129) of Canadian medical graduate FPs who complete at least some of their training at NOSM practise in northern Ontario. Slightly more than a quarter (21 of 79) of these FPs practise in rural northern Ontario. The FPs with more years of rural background or those with greater exposure to NOSM's medical education programs had higher odds of practising in rural northern Ontario. This study shows that NOSM is on the road to reaching one of its social accountability milestones.

Estimation of exposure to atmospheric pollutants during pregnancy integrating space-time activity and indoor air levels: does it make a difference?

PubMed Central

Marion, OUIDIR; Lise, GIORGIS-ALLEMAND; Sarah, LYON-CAEN; Xavier, MORELLI; Claire, CRACOWSKI; Sabrina, PONTET; Isabelle, PIN; Johanna, LEPEULE; Valérie, SIROUX; Rémy, SLAMA

2016-01-01

Studies of air pollution effects during pregnancy generally only consider exposure in the outdoor air at the home address. We aimed to compare exposure models differing in their ability to account for the spatial resolution of pollutants, space-time activity and indoor air pollution levels. We recruited 40 pregnant women in the Grenoble urban area, France, who carried a Global Positioning System (GPS) during up to 3 weeks; in a subgroup, indoor measurements of fine particles (PM2.5) were conducted at home (n=9) and personal exposure to nitrogen dioxide (NO2) was assessed using passive air samplers (n=10). Outdoor concentrations of NO2, and PM2.5 were estimated from a dispersion model with a fine spatial resolution. Women spent on average 16 h per day at home. Considering only outdoor levels, for estimates at the home address, the correlation between the estimate using the nearest background air monitoring station and the estimate from the dispersion model was high (r=0.93) for PM2.5 and moderate (r=0.67) for NO2. The model incorporating clean GPS data was less correlated with the estimate relying on raw GPS data (r=0.77) than the model ignoring space-time activity (r=0.93). PM2.5 outdoor levels were not to moderately correlated with estimates from the model incorporating indoor measurements and space-time activity (r=−0.10 to 0.47), while NO2 personal levels were not correlated with outdoor levels (r=−0.42 to 0.03). In this urban area, accounting for space-time activity little influenced exposure estimates; in a subgroup of subjects (n=9), incorporating indoor pollution levels seemed to strongly modify them. PMID:26300245

The ability of plasma cotinine to predict nicotine and carcinogen exposure is altered by differences in CYP2A6: the influence of genetics, race and sex

PubMed Central

Zhu, Andy Z.X.; Renner, Caroline C.; Hatsukami, Dorothy K.; Swan, Gary E.; Lerman, Caryn; Benowitz, Neal L.; Tyndale, Rachel F.

2013-01-01

Background Cotinine, a nicotine metabolite, is a biomarker of tobacco, nicotine and carcinogen exposure. However a given cotinine level may not represent the same tobacco exposure; for example, African Americans have higher cotinine levels than Caucasians after controlling for exposure. Methods Cotinine levels are determined by the amount of cotinine formation and the rate of cotinine removal which are both mediated by the enzyme CYP2A6. Since CYP2A6 activity differs by sex (estrogen induces CYP2A6) and genotype, their effect on cotinine formation and removal were measured in non-smoking Caucasians (Study 1, n=181) infused with labeled nicotine and cotinine. The findings were then extended to ad libitum smokers (Study 2, n=163). Results Study 1: Reduced CYP2A6 activity altered cotinine formation less than cotinine removal resulting in ratios of formation to removal of 1.31 and 1.12 in CYP2A6 reduced and normal metabolizers (P=0.01), or 1.39 and 1.12 in males and females (P=0.001), suggesting an overestimation of tobacco exposure in slower metabolizers. Study 2: Cotinine again overestimated tobacco and carcinogen exposure by ≥25% in CYP2A6 reduced metabolizers (≈2 fold between some genotypes) and in males. Conclusions In people with slower, relative to faster, CYP2A6 activity cotinine accumulates resulting in substantial differences in cotinine levels for a given tobacco exposure. Impact Cotinine levels may be misleading when comparing those with differing CYP2A6 genotypes within a race, between races with differing frequencies of CYP2A6 gene variants (i.e. African Americans have higher frequencies of reduced function variants contributing to their higher cotinine levels) or between the sexes. PMID:23371292

Changes in Pest Infestation Levels, Self-Reported Pesticide Use, and Permethrin Exposure during Pregnancy after the 2000–2001 U.S. Environmental Protection Agency Restriction of Organophosphates

PubMed Central

Williams, Megan K.; Rundle, Andrew; Holmes, Darrell; Reyes, Marilyn; Hoepner, Lori A.; Barr, Dana B.; Camann, David E.; Perera, Frederica P.; Whyatt, Robin M.

2008-01-01

Background Widespread residential pesticide use throughout the United States has resulted in ubiquitous, low-level pesticide exposure. The mix of active pesticide ingredients is changing in response to 2000–2001 regulations restricting use of the organophosphorus insecticides chlorpyrifos and diazinon. Objectives We aimed to determine the impact of U.S. Environmental Protection Agency regulations on pest infestation levels, pesticide use, and pesticides measured in indoor air samples. METHODOLOGY: 511 pregnant women from innercity New York were enrolled between 2000 and 2006. Permethrin, a pyrethroid insecticide; piperonyl butoxide (PBO), a pyrethroid synergist; chlorpyrifos; and diazinon were measured in 48-hr prenatal personal air samples. Data on pest infestation and pesticide use were collected via questionnaire. Results Eighty-eight percent of women reported using pesticides during pregnancy; 55% reported using higher-exposure pesticide applications (spray cans, pest bombs and/or professional pesticide applicators). Self-reported pest sightings and use of higher-exposure applications increased significantly after the regulations were implemented (p < 0.001). PBO, cis-, and trans-permethrin were detected in 75, 19, and 18% of personal air samples, respectively. Detection frequencies of PBO and cis- and trans-permethrin increased significantly over time (p < 0.05 controlling for potential confounders). Levels and/or detection frequencies of these compounds were significantly higher among mothers reporting use of high exposure pesticide applications (p ≤ 0.05). Chlorpyrifos and diazinon levels decreased significantly over time (p < 0.001). Conclusion In this cohort, pest infestations, use of pesticides, and use of permethrin appear to increase after the residential restriction of organophosphorus insecticides. This is one of the first studies to document widespread residential exposure to PBO. PMID:19079720

Lack of association between chronic exposure to biomass fuel smoke and markers of right ventricular pressure overload at high altitude

PubMed Central

Caravedo, Maria A.; Painschab, Matthew S.; Davila-Roman, Victor G.; De Ferrari, Aldo; Gilman, Robert H.; Vasquez-Villar, Angel D.; Pollard, Suzanne L.; Miranda, J. Jaime; Checkley, William

2014-01-01

Background Chronic exposure to biomass fuel smoke has been implicated in the development of pulmonary hypertension and right ventricular pressure/volume overload through activation of inflammation, increase in vascular resistance and endothelial dysfunction. We sought to compare N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) and echocardiography-derived pulmonary artery systolic pressure (PASP) levels in a high-altitude population-based study in Peru with and without chronic exposure to biomass fuel smoke. Methods NT-pro-BNP levels were measured in 519 adults (275 with and 244 without chronic exposure to biomass fuel smoke). Participants answered sociodemographics and clinical history questionnaires, underwent a clinical examination and blood testing for cardiopulmonary biomarkers. PASP was measured in a subgroup of 153 (31%) subjects. Results The study group consisted of 280 men (54%) and 239 women (46%). Average age was 56 years and average body mass index was 27 kg/m2. In multivariable analysis, there was no association between chronic exposure to biomass fuel smoke and NT-pro-BNP (p=0.31) or PASP (p=0.31). In the subgroup in which both NT-pro-BNP levels and PASP were measured, there was strong evidence of an association between these two variables (ρ=0.24, 95% CI 0.09-0.39; p=0.003). We found that age, high sensitivity C-reactive protein, being male and systolic blood pressure were positively associated with NT-pro-BNP levels whereas body mass index, LDL/HDL ratio and HOMA-IR were negatively associated (all p<0.01). Conclusions In this population-based study in a high-altitude setting, neither NT-pro-BNP levels nor echocardiography-derived PASP were associated with chronic exposure to biomass fuel smoke. PMID:25440802

Air pollution & the brain: Subchronic diesel exhaust exposure causes neuroinflammation and elevates early markers of neurodegenerative disease

PubMed Central

2011-01-01

Background Increasing evidence links diverse forms of air pollution to neuroinflammation and neuropathology in both human and animal models, but the effects of long-term exposures are poorly understood. Objective We explored the central nervous system consequences of subchronic exposure to diesel exhaust (DE) and addressed the minimum levels necessary to elicit neuroinflammation and markers of early neuropathology. Methods Male Fischer 344 rats were exposed to DE (992, 311, 100, 35 and 0 μg PM/m3) by inhalation over 6 months. Results DE exposure resulted in elevated levels of TNFα at high concentrations in all regions tested, with the exception of the cerebellum. The midbrain region was the most sensitive, where exposures as low as 100 μg PM/m3 significantly increased brain TNFα levels. However, this sensitivity to DE was not conferred to all markers of neuroinflammation, as the midbrain showed no increase in IL-6 expression at any concentration tested, an increase in IL-1β at only high concentrations, and a decrease in MIP-1α expression, supporting that compensatory mechanisms may occur with subchronic exposure. Aβ42 levels were the highest in the frontal lobe of mice exposed to 992 μg PM/m3 and tau [pS199] levels were elevated at the higher DE concentrations (992 and 311 μg PM/m3) in both the temporal lobe and frontal lobe, indicating that proteins linked to preclinical Alzheimer's disease were affected. α Synuclein levels were elevated in the midbrain in response to the 992 μg PM/m3 exposure, supporting that air pollution may be associated with early Parkinson's disease-like pathology. Conclusions Together, the data support that the midbrain may be more sensitive to the neuroinflammatory effects of subchronic air pollution exposure. However, the DE-induced elevation of proteins associated with neurodegenerative diseases was limited to only the higher exposures, suggesting that air pollution-induced neuroinflammation may precede preclinical markers of neurodegenerative disease in the midbrain. PMID:21864400

The distribution and extent of heavy metal accumulation in song sparrows along Arizona's upper Santa Cruz River

USGS Publications Warehouse

Lester, Michael B.; van Riper, Charles

2014-01-01

Heavy metals are persistent environmental contaminants, and transport of metals into the environment poses a threat to ecosystems, as plants and wildlife are susceptible to long-term exposure, bioaccumulation, and potential toxicity. We investigated the distribution and cascading extent of heavy metal accumulation in southwestern song sparrows (Melospiza melodia fallax), a resident riparian bird species that occurs along the US/Mexico border in Arizona’s upper Santa Cruz River watershed. This study had three goals: (1) quantify the degree of heavy metal accumulation in sparrows and determine the distributional patterns among study sites, (2) compare concentrations of metals found in this study to those found in studies performed prior to a 2009 international wastewater facility upgrade, and (3) assess the condition of song sparrows among sites with differing potential levels of exposure. We examined five study sites along with a reference site that reflect different potential sources of contamination. Body mass residuals and leukocyte counts were used to assess sparrow condition. Birds at our study sites typically had higher metal concentrations than birds at the reference site. Copper, mercury, nickel, and selenium in song sparrows did exceed background levels, although most metals were below background concentrations determined from previous studies. Song sparrows generally showed lower heavy metal concentrations compared to studies conducted prior to the 2009 wastewater facility upgrade. We found no cascading effects as a result of metal exposure.

Systemic and cerebral exposure to and pharmacokinetics of flavonols and terpene lactones after dosing standardized Ginkgo biloba leaf extracts to rats via different routes of administration

PubMed Central

Chen, Feng; Li, Li; Xu, Fang; Sun, Yan; Du, Feifei; Ma, Xutao; Zhong, Chenchun; Li, Xiuxue; Wang, Fengqing; Zhang, Nating; Li, Chuan

2013-01-01

BACKGROUND AND PURPOSE Flavonols and terpene lactones are putatively responsible for the properties of Ginkgo biloba leaf extracts that relate to prevention and treatment of cardiovascular disease and cerebral insufficiency. Here, we characterized rat systemic and cerebral exposure to these ginkgo compounds after dosing, as well as the compounds’ pharmacokinetics. EXPERIMENTAL APPROACH Rats received single or multiple doses of ShuXueNing injection (prepared from GBE50 for intravenous administration) or GBE50 (a standardized extract of G. biloba leaves for oral administration). Brain delivery of the ginkgo compounds was assessed with microdialysis. Various rat samples were analysed using liquid chromatography/mass spectrometry. KEY RESULTS Slow terminal elimination features of the flavonols counterbalanced the influence of poor oral bioavailability on their systemic exposure levels, which also resulted in significant accumulation of the compounds in plasma during the subchronic treatment with ShuXueNing injection and GBE50. Unlike the flavonols, the terpene lactones had poor enterohepatic circulation due to their rapid renal excretion and unknown metabolism. The flavonol glycosides occurred as major forms in plasma after dosing with ShuXueNing injection, while the flavonol aglycone conjugates were predominant in plasma after dosing with GBE50. Cerebral exposure was negligible for the flavonols and low for the terpene lactones. CONCLUSION AND IMPLICATIONS Unlike the significant systemic exposure levels, the levels of cerebral exposure to the flavonols and terpene lactones are low. The elimination kinetic differences between the two classes of ginkgo compounds influence their relative systemic exposure levels. The information gained is relevant to linking ginkgo administration to the medicinal effects. PMID:23808355

Developmental age strengthens barriers to ethanol accumulation in zebrafish.

PubMed

Lovely, C Ben; Nobles, Regina D; Eberhart, Johann K

2014-09-01

Fetal Alcohol Spectrum Disorders (FASD) describes a wide range of phenotypic defects affecting facial and neurological development associated with ethanol teratogenicity. It affects approximately 1 in 100 children born in the United States each year. Genetic predisposition along with timing and dosage of ethanol exposure are critical in understanding the prevalence and variability of FASD. The zebrafish attributes of external fertilization, genetic tractability, and high fecundity make it a powerful tool for FASD studies. However, a lack of consensus of ethanol treatment paradigms has limited the interpretation of these various studies. Here we address this concern by examining ethanol tissue concentrations across timing and genetic background. We utilize headspace gas chromatography to determine ethanol concentration in the AB, fli1:EGFP, and Tu backgrounds. In addition, we treated these embryos with ethanol over two different developmental time windows, 6-24 h post fertilization (hpf) and 24-48 hpf. Our analysis demonstrates that embryos rapidly equilibrate to a sub-media level of ethanol. Embryos then maintain this level of ethanol for the duration of exposure. The ethanol tissue concentration level is independent of genetic background, but is timing-dependent. Embryos exposed from 6 to 24 hpf were 2.7-4.2-fold lower than media levels, while embryos were 5.7-6.2-fold lower at 48 hpf. This suggests that embryos strengthen one or more barriers to ethanol as they develop. In addition, both the embryo and, to a lesser extent, the chorion, surrounding the embryo are barriers to ethanol. Overall, this work will help tighten ethanol treatment regimens and strengthen zebrafish as a model of FASD. Copyright © 2014 Elsevier Inc. All rights reserved.

Using air quality modeling to study source-receptor relationships between nitrogen oxides emissions and ozone exposures over the United States.

PubMed

Tong, Daniel Q; Muller, Nicholas Z; Kan, Haidong; Mendelsohn, Robert O

2009-11-01

Human exposure to ambient ozone (O(3)) has been linked to a variety of adverse health effects. The ozone level at a location is contributed by local production, regional transport, and background ozone. This study combines detailed emission inventory, air quality modeling, and census data to investigate the source-receptor relationships between nitrogen oxides (NO(x)) emissions and population exposure to ambient O(3) in 48 states over the continental United States. By removing NO(x) emissions from each state one at a time, we calculate the change in O(3) exposures by examining the difference between the base and the sensitivity simulations. Based on the 49 simulations, we construct state-level and census region-level source-receptor matrices describing the relationships among these states/regions. We find that, for 43 receptor states, cumulative NO(x) emissions from upwind states contribute more to O(3) exposures than the state's own emissions. In-state emissions are responsible for less than 15% of O(3) exposures in 90% of U.S. states. A state's NO(x) emissions can influence 2 to 40 downwind states by at least a 0.1 ppbv change in population-averaged O(3) exposure. The results suggest that the U.S. generally needs a regional strategy to effectively reduce O(3) exposures. But the current regional emission control program in the U.S. is a cap-and-trade program that assumes the marginal damage of every ton of NO(x) is equal. In this study, the average O(3) exposures caused by one ton of NO(x) emissions ranges from -2.0 to 2.3 ppm-people-hours depending on the state. The actual damage caused by one ton of NO(x) emissions varies considerably over space.

Long-Term Exposure to Low-Level Arsenic in Drinking Water and Diabetes Incidence: A Prospective Study of the Diet, Cancer and Health Cohort

PubMed Central

Bräuner, Elvira Vaclavik; Nordsborg, Rikke Baastrup; Andersen, Zorana Jovanovic; Tjønneland, Anne; Loft, Steffen

2014-01-01

Background: Established causes of diabetes do not fully explain the present epidemic. High-level arsenic exposure has been implicated in diabetes risk, but the effect of low-level arsenic exposure in drinking water remains unclear. Objective: We sought to determine whether long-term exposure to low-level arsenic in drinking water in Denmark is associated with an increased risk of diabetes using a large prospective cohort. Methods: During 1993–1997, we recruited 57,053 persons. We followed each cohort member for diabetes occurrence from enrollment until 31 December 2006. We traced and geocoded residential addresses of the cohort members and used a geographic information system to link addresses with water-supply areas. We estimated individual exposure to arsenic using all addresses from 1 January 1971 until the censoring date. Cox proportional hazards models were used to model the association between arsenic exposure and diabetes incidence, separately for two definitions of diabetes: all cases and a more strict definition in which cases of diabetes based solely on blood glucose results were excluded. Results: Over a mean follow-up period of 9.7 years for 52,931 eligible participants, there were a total of 4,304 (8.1%) diabetes cases, and 3,035 (5.8%) cases of diabetes based on the more strict definition. The adjusted incidence rate ratios (IRRs) per 1-μg/L increment in arsenic levels in drinking water were as follows: IRR = 1.03 (95% CI: 1.01, 1.06) and IRR = 1.02 (95% CI: 0.99, 1.05) for all and strict diabetes cases, respectively. Conclusions: Long-term exposure to low-level arsenic in drinking water may contribute to the development of diabetes. Citation: Bräuner EV, Nordsborg RB, Andersen ZJ, Tjønneland A, Loft S, Raaschou-Nielsen O. 2014. Long-term exposure to low-level arsenic in drinking water and diabetes incidence: a prospective study of the Diet, Cancer and Health cohort. Environ Health Perspect 122:1059–1065; http://dx.doi.org/10.1289/ehp.1408198 PMID:24927198

Determination of an Environmental Background Level of Sr-90 in Urine for the Hanford Bioassay Program Determination of an Environmental Background Level of Sr-90 in Urine for the Hanford Bioassay Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antonio, Cheryl L.; Rivard, James W.

2009-11-01

During the decommissioning and maintenance of some of the facilities at the U.S. Department of Energy Hanford Site in Washington State, workers have potential for a 90Sr intake. However, because of worldwide radioactive fallout, 90Sr is present in our environment, and can be detectable in routine urine bioassay samples. It is important for the Hanford Site bioassay program to discern an occupational intake from a non-occupational environmental one. A detailed study of the background 90Sr in the urine of unexposed Hanford workers was performed. A survey of the Hanford Site bioassay database found 128 Hanford workers who were hired betweenmore » 1997 and 2002 and who had a very low potential for an occupational exposure prior to the baseline strontium urinalysis. Each urinalysis sample represented excretion during an approximate 24-hr period. The arithmetic mean value for the 128 pre-exposure baselines was 3.6 ± 5.1 mBq d-1. The 90Sr activities in urine varied from -12 to 20 mBq. The 99th percentile result was 16.4 mBqd-1, which was interpreted to mean that 1% of Hanford workers not occupationally exposed to strontium might exceed 16.4 mBq d-1.« less

Risk of Asthmatic Episodes in Children Exposed to Sulfur Dioxide Stack Emissions from a Refinery Point Source in Montreal, Canada

PubMed Central

Smargiassi, Audrey; Kosatsky, Tom; Hicks, John; Plante, Céline; Armstrong, Ben; Villeneuve, Paul J.; Goudreau, Sophie

2009-01-01

Background Little is known about the respiratory effects of short-term exposures to petroleum refinery emissions in young children. This study is an extension of an ecologic study that found an increased rate of hospitalizations for respiratory conditions among children living near petroleum refineries in Montreal (Canada). Methods We used a time-stratified case–crossover design to assess the risk of asthma episodes in relation to short-term variations in sulfur dioxide levels among children 2–4 years of age living within 0.5–7.5 km of the refinery stacks. Health data used to measure asthma episodes included emergency department (ED) visits and hospital admissions from 1996 to 2004. We estimated daily levels of SO2 at the residence of children using a) two fixed-site SO2 monitors located near the refineries and b) the AERMOD (American Meteorological Society/Environmental Protection Agency Regulatory Model) atmospheric dispersion model. We used conditional logistic regression to estimate odds ratios associated with an increase in the interquartile range of daily SO2 mean and peak exposures (31.2 ppb for AERMOD peaks). We adjusted for temperature, relative humidity, and regional/urban background air pollutant levels. Results The risks of asthma ED visits and hospitalizations were more pronounced for same-day (lag 0) SO2 peak levels than for mean levels on the same day, or for other lags: the adjusted odds ratios estimated for same-day SO2 peak levels from AERMOD were 1.10 [95% confidence interval (CI), 1.00–1.22] and 1.42 (95% CI, 1.10–1.82), over the interquartile range, for ED visits and hospital admissions, respectively. Conclusions Short-term episodes of increased SO2 exposures from refinery stack emissions were associated with a higher number of asthma episodes in nearby children. PMID:19440507

Lung pathology in response to repeated exposure to Staphylococcus aureus in congenic residual function cystic fibrosis mice does not increase in response to decreased CFTR levels or increased bacterial load.

PubMed

Davidson, Donald J; Webb, Sheila; Teague, Peter; Govan, John R W; Dorin, Julia R

2004-01-01

To establish the role of defects in murine Cftr in the susceptibility to Staphylococcus aureus lung disease using mouse models of cystic fibrosis (CF), congenic or inbred strains. We describe the histopathological analyses of CF mice repeatedly exposed by aerosolisation to a CF isolate of S. aureus, using residual function Cftr mice and compound heterozygotes generated by intercrossing these with Cftr 'null' mice, all congenic on the C57Bl6/N background. We demonstrate that mice congenic on the C57Bl/6 background develop significantly more severe lung pathology than non-CF littermates in response to repeated exposure to the most frequent early CF lung pathogen S. aureus. Furthermore, reducing the level of Cftr by half in compound heterozygote mice does not impact upon disease severity, even in response to an increased bacterial dose. These results are consistent with an airway clearance defect, or abnormal inflammatory response secondary to Cftr mutation. These studies confirm the primary role for Cftr mutation in the development of this lung phenotype. In addition, these results demonstrate that a further 50% decrease in residual wild-type Cftr mRNA levels in this model does not impact the severity of the histopathological response to S. aureus, suggesting a critical threshold level for functional CFTR. Copyright 2004 S. Karger AG, Basel

Work-Related Violence, Lifestyle, and Health among Special Education Teachers Working in Finnish Basic Education

ERIC Educational Resources Information Center

Ervasti, Jenni; Kivimaki, Mika; Pentti, Jaana; Salmi, Venla; Suominen, Sakari; Vahtera, Jussi; Virtanen, Marianna

2012-01-01

Background: Studies have reported higher levels of absenteeism due to illness among special education teachers compared to other teachers, but it is not known which factors might contribute to this difference. We examined whether health, health behaviors, and exposure to violence at work differed between special education and general education…

Preventing Lead Poisoning in Young Children. A Statement by the Centers for Disease Control.

ERIC Educational Resources Information Center

Centers for Disease Control (DHHS/PHS), Atlanta, GA.

This document is the fourth revision of a statement by the Centers for Disease Control. Introductory and background chapters present data that indicate significant adverse effects of lead levels in children's blood that were previously believed to be safe. Other chapters discuss: (1) sources of lead exposure, including paint, soil and dust, and…

Personally Modifiable Risk Factors Associated with Pediatric Hearing Loss: A Systematic Review

PubMed Central

Vasconcellos, Adam P.; Kyle, Meghann E.; Gilani, Sapideh; Shin, Jennifer J.

2015-01-01

Background Pediatric hearing loss is an increasingly recognized problem with significant implications. Increasing our quantitative understanding of potentially modifiable environmental risk factors for hearing loss may form the foundation for prevention and screening programs. Objective To determine whether specific threshold exposure levels of personally modifiable risk factors for hearing loss have been defined, with the overarching goal of providing actionable guidance for the prevention of pediatric hearing loss. Data Sources A systematic review was performed. Computerized searches of PubMed, EMBASE, and the Cochrane Library were completed and supplemented with manual searches. Review Methods Inclusion/exclusion criteria were designed to determine specific threshold values of personally modifiable risk factors on hearing loss in the pediatric population. Searches and data extraction were performed by independent reviewers. Results There were 38 criterion-meeting studies, including a total of 50,651 subjects. Threshold noise exposures significantly associated with hearing loss in youth included: (1) more than 4 hours per week or more than 5 years of personal headphone usage, (2) more than 4 visits per month to a discotheque, and (3) working on a mechanized farm. Quantified tobacco levels of concern included any level of in utero smoke exposure as well as secondhand exposure sufficient to elevate serum cotinine. Conclusions Specific thresholds analyses are limited. Future studies would ideally focus on stratifying risk according to clearly defined levels of exposure, in order to provide actionable guidance for children and families. PMID:24671457

HZE particle radiation induces tissue-specific and p53-dependent mutagenesis in transgenic animals

NASA Technical Reports Server (NTRS)

Chang, P. Y.; Kanazawa, N.; Lutze-Mann, L.; Winegar, R.

2001-01-01

Transgenic animals, with the integrated target gene, provide a unique approach for measuring and characterizing mutations in any tissue of the animal. We are using the plasmid-based lacZ transgenic mice with different p53 genetic background to examine radiation-induced genetic damage resulting from exposure to heavy particle radiation. We measured lacZ mutation frequencies (MF) in the brain and spleen tissues at various times after exposing animals to an acute dose of 1 Gy of 1GeV/amu iron particles. MF in the spleen of p53+/+ animals increased up to 2.6-fold above spontaneous levels at 8 weeks post irradiation. In contrast, brain MF from the same animals increased 1.7-fold above controls in the same period. In the p53-/- animals, brain MF increased to 2.2-fold above spontaneous levels at 1 week after treatment, but returned to control levels thereafter. Radiation also induced alterations in the spectrum of mutants in both tissues, accompanied by changes in the frequency of mutants with deletions extending past the transgene into mouse genomic DNA. Our results indicate that the accumulation of transgene MF after radiation exposure is dependant on the tissue examined as well as the p53 genetic background of the animals.

Altitude, radiation, and mortality from cancer and heart disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weinberg, C.R.; Brown, K.G.; Hoel, D.G.

The variation in background radiation levels is an important source of information for estimating human risks associated with low-level exposure to ionizing radiation. Several studies conducted in the United States, correlating mortality rates for cancer with estimated background radiation levels, found an unexpected inverse relationship. Such results have been interpreted as suggesting that low levels of ionizing radiation may actually confer some benefit. An environmental factor strongly correlated with background radiation is altitude. Since there are important physiological adaptations associated with breathing thinner air, such changes may themselves influence risk. We therefore fit models that simultaneously incorporated altitude and backgroundmore » radiation as predictors of mortality. The negative correlations with background radiation seen for mortality from arteriosclerotic heart disease and cancers of the lung, the intestine, and the breast disappeared or became positive once altitude was included in the models. By contrast, the significant negative correlations with altitude persisted with adjustment for radiation. Interpretation of these results is problematic, but recent evidence implicating reactive forms of oxygen in carcinogenesis and atherosclerosis may be relevant. We conclude that the cancer correlational studies carried out in the United States using vital statistics data do not in themselves demonstrate a lack of carcinogenic effect of low radiation levels, and that reduced oxygen pressure of inspired air may be protective against certain causes of death.« less

Noise characteristics of CT perfusion imaging: how does noise propagate from source images to final perfusion maps?

NASA Astrophysics Data System (ADS)

Li, Ke; Chen, Guang-Hong

2016-03-01

Cerebral CT perfusion (CTP) imaging is playing an important role in the diagnosis and treatment of acute ischemic strokes. Meanwhile, the reliability of CTP-based ischemic lesion detection has been challenged due to the noisy appearance and low signal-to-noise ratio of CTP maps. To reduce noise and improve image quality, a rigorous study on the noise transfer properties of CTP systems is highly desirable to provide the needed scientific guidance. This paper concerns how noise in the CTP source images propagates to the final CTP maps. Both theoretical deviations and subsequent validation experiments demonstrated that, the noise level of background frames plays a dominant role in the noise of the cerebral blood volume (CBV) maps. This is in direct contradiction with the general belief that noise of non-background image frames is of greater importance in CTP imaging. The study found that when radiation doses delivered to the background frames and to all non-background frames are equal, lowest noise variance is achieved in the final CBV maps. This novel equality condition provides a practical means to optimize radiation dose delivery in CTP data acquisition: radiation exposures should be modulated between background frames and non-background frames so that the above equality condition is satisïnAed. For several typical CTP acquisition protocols, numerical simulations and in vivo canine experiment demonstrated that noise of CBV can be effectively reduced using the proposed exposure modulation method.

A Human Mixture Risk Assessment for Neurodevelopmental Toxicity Associated with Polybrominated Diphenyl Ethers Used as Flame Retardants

PubMed Central

Martin, Olwenn V.; Evans, Richard M.; Faust, Michael

2017-01-01

Background: The European Food Safety Authority recently concluded that the exposure of small children (1–3 y old) to brominated diphenyl ether (BDE)-99 may exceed acceptable levels defined in relation to neurodevelopmental toxicity in rodents. The flame retardant BDE-209 may release BDE-99 and other lower brominated BDEs through biotic and abiotic degradation, and all age groups are exposed not only to BDE-209 and -99 but also to a cocktail of BDE congeners with evidence of neurodevelopmental toxicity. The possible risks from combined exposures to these substances have not been evaluated. Objectives: We performed a congener-specific mixture risk assessment (MRA) of human exposure to combinations of BDE-209 and other BDEs based on estimated exposures via diet and dust intake and on measured levels in biologic samples. Methods: We employed the Hazard Index (HI) method by using BDE congener-specific reference doses for neurodevelopmental toxicity. Results: Our HI analysis suggests that combined exposures to polybrominated diphenyl ethers (PBDEs) may exceed acceptable levels in breastfeeding infants (0–3 mo old) and in small children (1–3 y old), even for moderate (vs. high) exposure scenarios. Our estimates also suggest that acceptable levels of combined PBDEs may be exceeded in adults whose diets are high in fish. Small children had the highest combined exposures, with some estimated body burdens that were similar to body burdens associated with developmental neurotoxicity in rodents. Conclusions: Our estimates corroborate reports from several recent epidemiological studies of associations between PBDE exposures and neurobehavioral outcomes, and they support the inclusion of BDE-209 in the persistent organic pollutant (POP) convention as well as the need for strategies to reduce exposures to PBDE mixtures, including maximum residue limits for PBDEs in food and measures for limiting the release of PBDEs from consumer waste. https://doi.org/10.1289/EHP826 PMID:28886598

Exposure to Traffic-Related Air Pollution and Serum Inflammatory Cytokines in Children

PubMed Central

Merid, Simon Kebede; Gref, Anna; Gajulapuri, Ashwini; Lemonnier, Nathanaël; Ballereau, Stéphane; Gigante, Bruna; Kere, Juha; Auffray, Charles; Melén, Erik; Pershagen, Göran

2017-01-01

Background: Long-term exposure to ambient air pollution can lead to adverse health effects in children; however, underlying biological mechanisms are not fully understood. Objectives: We evaluated the effect of air pollution exposure during different time periods on mRNA expression as well as circulating levels of inflammatory cytokines in children. Methods: We measured a panel of 10 inflammatory markers in peripheral blood samples from 670 8-y-old children in the Barn/Child, Allergy, Milieu, Stockholm, Epidemiology (BAMSE) birth cohort. Outdoor concentrations of nitrogen dioxide (NO2) and particulate matter (PM) with aerodynamic diameter <10μm (PM10) from road traffic were estimated for residential, daycare, and school addresses using dispersion modeling. Time-weighted average exposures during infancy and at biosampling were linked to serum cytokine levels using linear regression analysis. Furthermore, gene expression data from 16-year-olds in BAMSE (n=238) were used to evaluate links between air pollution exposure and expression of genes coding for the studied inflammatory markers. Results: A 10 μg/m3 increase of NO2 exposure during infancy was associated with a 13.6% (95% confidence interval (CI): 0.8; 28.1%) increase in interleukin-6 (IL-6) levels, as well as with a 27.8% (95% CI: 4.6, 56.2%) increase in IL-10 levels, the latter limited to children with asthma. However, no clear associations were observed for current exposure. Results were similar using PM10, which showed a high correlation with NO2. The functional analysis identified several differentially expressed genes in response to air pollution exposure during infancy, including IL10, IL13, and TNF. Conclusion: Our results indicate alterations in systemic inflammatory markers in 8-y-old children in relation to early-life exposure to traffic-related air pollution. https://doi.org/10.1289/EHP460 PMID:28669936

A biological indicator of inorganic arsenic exposure using the sum of urinary inorganic arsenic and monomethylarsonic acid concentrations

PubMed Central

Hata, Akihisa; Kurosawa, Hidetoshi; Endo, Yoko; Yamanaka, Kenzo; Fujitani, Noboru; Endo, Ginji

2016-01-01

Objectives: The sum of urinary inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) concentrations is used for the biological monitoring of occupational iAs exposure. Although DMA is a major metabolite of iAs, it is an inadequate index because high DMA levels are present in urine after seafood consumption. We estimated the urinary iAs+MMA concentration corresponding to iAs exposure. Methods: We used data from two arsenic speciation analyses of urine samples from 330 Bangladeshi with oral iAs exposure and 172 Japanese workers without occupational iAs exposure using high-performance liquid chromatography with inductively coupled plasma mass spectrometry. Results: iAs, MMA, and DMA, but not arsenobetaine (AsBe), were detected in the urine of the Bangladeshi subjects. The correlation between iAs+MMA+DMA and iAs+MMA was obtained as log (iAs+MMA) = 1.038 log (iAs+MMA+DMA) -0.658. Using the regression formula, the iAs+MMA value was calculated as 2.15 and 7.5 μg As/l, corresponding to 3 and 10 μg As/m3 of exposures, respectively. In the urine of the Japanese workers, arsenic was mostly excreted as AsBe. We used the 95th percentile of iAs+MMA (12.6 μg As/l) as the background value. The sum of the calculated and background values can be used as a biological indicator of iAs exposure. Conclusion: We propose 14.8 and 20.1 μg As/l of urinary iAs+MMA as the biological indicators of 3 and 10 μg As/m3 iAs exposure, respectively. PMID:27010090

Case study on risk evaluation of printed electronics using nanosilver ink.

PubMed

Kim, Ellen; Lee, Ji Hyun; Kim, Jin Kwon; Lee, Gun Ho; Ahn, Kangho; Park, Jung Duck; Yu, Il Je

2016-01-01

With the ever-increasing development of nanotechnology, our society is being surrounded by possible risks related to exposure to manufactured nanomaterials. The consumer market already includes many products that contain silver nanoparticles (AgNPs), including various household products, such as yoga mats, cutting boards, running shirts, and socks. There is a growing concern over the release of AgNPs in workplaces related to the manufacture and application of nanomaterials. This study investigated the release of AgNPs during the operation of a printed electronics printer. Using an exposure simulation chamber, a nanoparticle collector, scanning mobility particle sizer (SMPS), condensation particle counter (CPC), dust monitor, and mixed cellulose ester (MCE) filters are all connected to measure the AgNP exposure levels when operating a printed electronics printer. A very small amount of AgNPs was released during the operation of the printed electronics printer, and the number of AgNPs inside the exposure simulation chamber was lower than that outside background. In addition, when evaluating the potential risks for consumers and workers using a margin of exposure (MOE) approach and target MOE of 1000, the operational results far exceeded the target MOE in this simulation study and in a previous workplace exposure study. The overall results indicate a no-risk concern level in the case of printed electronics using nanosilver ink.

Childhood Lead Exposure from Battery Recycling in Vietnam

PubMed Central

Van Tung, Lo; Wallace, Ryan M.; Havens, Deborah J.; Karr, Catherine J.; Bich Diep, Nguyen; Croteau, Gerry A.; Beaudet, Nancy J.; Duy Bao, Nguyen

2015-01-01

Background. Battery recycling facilities in developing countries can cause community lead exposure. Objective. To evaluate child lead exposure in a Vietnam battery recycling craft village after efforts to shift home-based recycling outside the village. Methods. This cross-sectional study evaluated 109 children in Dong Mai village, using blood lead level (BLL) measurement, parent interview, and household observation. Blood samples were analyzed with a LeadCare II field instrument; highest BLLs (≥45 μg/dL) were retested by laboratory analysis. Surface and soil lead were measured at 11 households and a school with X-ray fluorescence analyzer. Results. All children had high BLLs; 28% had BLL ≥45 μg/dL. Younger age, family recycling, and outside brick surfaces were associated with higher BLL. Surface and soil lead levels were high at all tested homes, even with no recycling history. Laboratory BLLs were lower than LeadCare BLLs, in 24 retested children. Discussion. In spite of improvements, lead exposure was still substantial and probably associated with continued home-based recycling, legacy contamination, and workplace take-home exposure pathways. There is a need for effective strategies to manage lead exposure from battery recycling in craft villages. These reported BLL values should be interpreted cautiously, although the observed field-laboratory discordance may reflect bias in laboratory results. PMID:26587532

Evaluation of Exposure to Arsenic in Residential Soil

PubMed Central

Tsuji, Joyce S.; Van Kerkhove, Maria D.; Kaetzel, Rhonda S.; Scrafford, Carolyn G.; Mink, Pamela J.; Barraj, Leila M.; Crecelius, Eric A.; Goodman, Michael

2005-01-01

In response to concerns regarding arsenic in soil from a pesticide manufacturing plant, we conducted a biomonitoring study on children younger than 7 years of age, the age category of children most exposed to soil. Urine samples from 77 children (47% participation rate) were analyzed for total arsenic and arsenic species related to ingestion of inorganic arsenic. Older individuals also provided urine (n = 362) and toenail (n = 67) samples. Speciated urinary arsenic levels were similar between children (geometric mean, geometric SD, and range: 4.0, 2.2, and 0.89–17.7 μg/L, respectively) and older participants (3.8, 1.9, 0.91–19.9 μg/L) and consistent with unexposed populations. Toenail samples were < 1 mg/kg. Correlations between speciated urinary arsenic and arsenic in soil (r = 0.137, p = 0.39; n = 41) or house dust (r = 0.049, p = 0.73; n = 52) were not significant for children. Similarly, questionnaire responses indicating soil exposure were not associated with increased urinary arsenic levels. Relatively low soil arsenic exposure likely precluded quantification of arsenic exposure above background. PMID:16330356

The impact of long-term mercury contamination on the new human exposure scenarios in the North Region of Mato Grosso, Amazon basin

NASA Astrophysics Data System (ADS)

de Souza Hacon, S.; Aparecido de Farinas, R.; Reis Argento, R.; Campos, R. C.; Rossi, A. P.; Wasserman, J.

2003-05-01

The present study, addresses the long-term mercury contamination as consequence of the goldmining activities taking into account the fish Hg levels and fish consumption in different areas in the north region of the Mato Grosso State. The study involves the enviromnental characterization of the region, glor, and the fish-farming areas. Geographic Information has been emphased on the cultural and social habits by a specific questionnaire. A monitoring mercury program was carried out, taking different fish species from contaminated and background areas. The results show that in Alta Floresta Hg levels of the piscivorous fish are decreasing in comparison with the previous exposure scenario. The present exposure scenario ranges from 0.09 to 3.9 μg/kg/d. The highest exposure dose was detected in the rural area of Paranaíta and the lowest in Nova Monte Verde. The results of this study support govermental decision-makers and local community's representatives to deliberate conservative measures to protect human health.

Exposure to Terrorism and Israeli Youths’ Cigarette, Alcohol, and Cannabis Use

PubMed Central

Schiff, Miriam; Zweig, Hillah Haim; Benbenishty, Rami; Hasin, Deborah S.

2007-01-01

Objectives. We investigated the consequences of exposure to acts of terrorism among Israeli adolescents. We examined whether exposure to terrorism predicted adolescents’ use of cigarettes, alcohol (including binge drinking), and cannabis after we controlled for posttraumatic stress and depressive symptoms and background variables. Methods. Anonymous self-administered questionnaires were given to a random sample of 960 10th and 11th grade students (51.6% boys, 48.4% girls) in a large city in northern Israel. Results. Close physical exposure to acts of terrorism predicted higher levels of alcohol consumption (including binge drinking among drinkers) and cannabis use. These relationships remained even after we controlled for posttraumatic stress and depressive symptoms. Conclusions. In addition to posttraumatic stress symptoms, negative consequences of terrorism exposure among adolescents included substance abuse. The similarity between our findings among Israeli adolescents and previous findings among US adults suggests cross-cultural generalizability. Given the risks for later problems from early-onset substance abuse, the consequences of terrorism exposure among adolescents merit greater research and clinical attention. PMID:17761574

Using exterior building surface films to assess human exposure and health risks from PCDD/Fs in New York City, USA, after the World Trade Center attacks.

PubMed

Rayne, Sierra

2005-12-09

Concentrations of tetra- through octa-chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were determined in exterior window films from Manhattan and Brooklyn in New York City (NYC), USA, 6 weeks after the World Trade Center (WTC) attacks of 11 September 2001. High concentrations of the 2,3,7,8-substituted congeners (P(2378)CDD/Fs) were observed, at levels up to 6600 pg-TEQ g(-1) nearest the WTC site. An equilibrium partitioning model was developed to reconstruct total gas + particle-phase atmospheric concentrations of P(2378)CDD/Fs at each site. The reconstructed atmospheric and window film concentrations were subsequently used in a preliminary human health risk assessment to estimate the potential cancer and non-cancer risks posed to residents of lower Manhattan from these contaminants over the 6 week exposure period between the WTC attacks and sampling dates. Residents of lower Manhattan appear to have a slightly elevated cancer risk (up to 1.6% increase over background) and increased P(2378)CDD/F body burden (up to 8.0% increase over background) because of above-background exposure to high concentrations of P(2378)CDD/Fs produced from the WTC attacks during the short period between 11 September 2001, and window film sampling 6 weeks later.

Protective Efficacy of Selenite against Lead-Induced Neurotoxicity in Caenorhabditis elegans

PubMed Central

Tseng, I-Ling; Liao, Vivian Hsiu-Chuan

2013-01-01

Background Selenium is an essential micronutrient that has a narrow exposure window between its beneficial and toxic effects. This study investigated the protective potential of selenite (IV) against lead (Pb(II))-induced neurotoxicity in Caenorhabditis elegans. Principal Findings The results showed that Se(IV) (0.01 µM) pretreatment ameliorated the decline of locomotion behaviors (frequencies of body bends, head thrashes, and reversal ) of C. elegans that are damaged by Pb(II) (100 µM) exposure. The intracellular ROS level of C. elegans induced by Pb(II) exposure was significantly lowered by Se(IV) supplementation prior to Pb(II) exposure. Finally, Se(IV) protects AFD sensory neurons from Pb(II)-induced toxicity. Conclusions Our study suggests that Se(IV) has protective activities against Pb(II)-induced neurotoxicity through its antioxidant property. PMID:23638060

Interaction between Y chromosome haplogroup O3* and 4-n-octylphenol exposure reduces the susceptibility to spermatogenic impairment in Han Chinese.

PubMed

Hu, Weiyue; Chen, Minjian; Ji, Juan; Qin, Yufeng; Zhang, Feng; Xu, Miaofei; Wu, Wei; Du, Guizhen; Wu, Di; Han, Xiumei; Jin, Li; Xia, Yankai; Lu, Chuncheng; Wang, Xinru

2017-10-01

Certain genetic background (mainly Y chromosome haplogroups, Y-hg) may modify the susceptibility of certain environmental exposure to some diseases. Compared with respective main effects of genetic background or environmental exposure, interactions between them reflect more realistic combined effects on the susceptibility to a disease. To identify the interactions on spermatogenic impairment, we performed Y chromosome haplotyping and measurement of 9 urinary phenols concentrations in 774 infertile males and 520 healthy controls in a Han Chinese population, and likelihood ratio tests were used to examine the interactions between Y-hgs and phenols. Originally, we observed that Y-hg C and Y-hg F * might modify the susceptibility to male infertility with urinary 4-n-octylphenol (4-n-OP) level (P inter = 0.005 and 0.019, respectively). Subsequently, based on our results, two panels were tested to identify the possible protective sub-branches of Y-hg F * to 4-n-OP exposure, and Y-hg O3 * was uncovered to interact with 4-n-OP (P inter = 0.019). In conclusion, while 4-n-OP shows an adverse effect on spermatogenesis, Y-hg O3 * makes individuals more adaptive to such an effect for maintaining basic reproductive capacity. Copyright © 2017 Elsevier Inc. All rights reserved.

Camera/Photometer Results

NASA Astrophysics Data System (ADS)

Clifton, K. S.; Owens, J. K.

1983-04-01

Efforts continue regarding the analysis of particulate contamination recorded by the Camera/Photometers on STS-2. These systems were constructed by Epsilon Laboratories, Inc. and consisted of two 16-mm photographic cameras, using Kodak Double X film, Type 7222, to make stereoscopic observations of contaminant particles and background. Each was housed within a pressurized canister and operated automatically throughout the mission, making simultaneous exposures on a continuous basis every 150 sec. The cameras were equipped with 18-mm f/0.9 lenses and subtended overlapping 20° fields-of-view. An integrating photometer was used to inhibit the exposure sequences during periods of excessive illumination and to terminate the exposures at preset light levels. During the exposures, a camera shutter operated in a chopping mode in order to isolate the movement of particles for velocity determinations. Calculations based on the preflight film calibration indicate that particles as small as 25 μm can be detected from ideal observing conditions. Current emphasis is placed on the digitization of the photographic data frames and the determination of particle distances, sizes, and velocities. It has been concluded that background bright-ness measurements cannot be established with any reliability on the STS-2 mission, due to the preponderance of Earth-directed attitudes and the incidence of light reflected from nearby surfaces.

Biomonitoring the Cooked Meat Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in Hair: Impact of Exposure, Pigmentation and Cytochrome P450 1A2 Phenotype

PubMed Central

Turesky, Robert J.; Liu, Lin; Gu, Dan; Yonemori, Kim M.; White, Kami K.; Wilkens, Lynne R.; Marchand, Loic Le

2013-01-01

Background Hair is a promising tissue to assess exposure to 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a carcinogen formed in cooked meats. However, an understanding of how dietary exposure to PhIP, cytochrome P450 1A2 activity - a key enzyme involved in PhIP metabolism, and hair pigmentation affect the level of PhIP accrued in hair is required in order to determine the reliability of the PhIP hair level as a biomarker of exposure to this carcinogen. Methods We examined the impact of PhIP exposure, cytochrome P450 1A2 activity, and hair pigmentation on the levels of PhIP accumulated in the hair of volunteers on a 4-week semi-controlled diet of cooked meat containing known quantities of PhIP. Results The amount of PhIP in hair increased, on average, 15-fold in light- and dark-haired individuals during consumption of cooked meat. PhIP levels in hair were correlated to PhIP intake (ρ = 0.53; p < 0.001), and the relationship was strengthened when PhIP levels were normalized for the melanin content of hair (ρ = 0.71; p < 0.001). However, PhIP accrual in hair was not correlated to cytochrome P450 1A2 activity, as assessed by the caffeine test, or to the levels of unmetabolized PhIP in urine, or to the metabolic ratio of the major urinary metabolite N2-(ß-1-glucosiduronyl-2-(hydroxyamino)-1-methyl-6-phenylimidazo[4,5-b]pyridine to unmetabolized PhIP. Conclusions The employment of the PhIP hair biomarker should take hair pigmentation into account for accurate exposure assessment. Impact PhIP hair levels can serve as a biomarker in epidemiological studies investigating the association of HAAs, cooked meat and cancer risk. PMID:23329727

Chronic occupational exposure to hexavalent chromium causes DNA damage in electroplating workers

PubMed Central

2011-01-01

Background Occupational exposure to chromium compounds may result in adverse health effects. This study aims to investigate whether low-level hexavalent chromium (Cr(VI)) exposure can cause DNA damage in electroplating workers. Methods 157 electroplating workers and 93 control subjects with no history of occupational exposure to chromium were recruited in Hangzhou, China. Chromium levels in erythrocytes were determined by graphite furnace atomic absorption spectrophotometer. DNA damage in peripheral lymphocytes was evaluated with the alkaline comet assay by three parameters: Olive tail moment, tail length and percent of DNA in the comet tail (tail DNA%). Urinary 8-OHdG levels were measured by ELISA. Results Chromium concentration in erythrocytes was about two times higher in electroplating workers (median: 4.41 μg/L) than that in control subjects (1.54 μg/L, P < 0.001). The medians (range) of Olive tail moment, tail length and tail DNA% in exposed workers were 1.13 (0.14-6.77), 11.17 (3.46-52.19) and 3.69 (0.65-16.20), and were significantly higher than those in control subjects (0.14 (0.01-0.39), 3.26 (3.00-4.00) and 0.69 (0.04-2.74), P < 0.001). Urinary 8-OHdG concentration was 13.65 (3.08-66.30) μg/g creatinine in exposed workers and 8.31 (2.94-30.83) μg/g creatinine in control subjects (P < 0.001). The differences of urinary 8-OHdG levels, Olive tail moment, tail length and tail DNA% between these two groups remained significant (P < 0.001) even after stratification by potential confounding factors such as age, gender, and smoking status. Chromium exposure was found to be positively associated with chromium levels in erythrocytes, urinary 8-OHdG levels, Olive tail moment, tail length and tail DNA%. Positive dose-response associations were also found between chromium levels in erythrocytes and Olive tail moment, tail length and tail DNA%. Conclusion The findings in this study indicated that there was detectable chromium exposure in electroplating workers. Low-level occupational chromium exposure induced DNA damage. PMID:21481275

Assessment of Health Consequences of Steel Industry Welders’ Occupational Exposure to Ultraviolet Radiation

PubMed Central

Zamanian, Zahra; Mortazavi, Saied Mohammad Javad; Asmand, Ebrahim; Nikeghbal, Kiana

2015-01-01

Background: Welding is among the most important frequently used processes in the industry with a wide range of applications from the food industry to aerospace and from precision tools to shipbuilding. The aim of this study was to assess the level of steel industry welders’ exposure to ultraviolet (UV) radiation and to investigate the health impacts of these exposures. Methods: In this case–control study, we measured the intensity of UV at the workers’ wrist in Fars Steel Company through manufacture of different types of heavy metal structures, using UV-meter model 666230 made by Leybold Co., from Germany. Results: The population under the study comprised 400 people including 200 welders as the exposed group and 200 nonwelders as the unexposed group. The results of the questionnaire were analyzed using SPSS software, version 19. The average, standard deviation, maximum and minimum of the UV at the welders’ wrist were 0.362, 0.346, 1.27, and 0.01 μW/cm2, respectively. There was a significantly (P < 0.01) higher incidence of cataracts, keratoconjunctivitis, dermatitis and erythema in welders than in their nonwelders. Conclusions: This study showed that the time period of UV exposure in welders is higher than the permissible contact threshold level. Therefore, considering the outbreak of the eye and skin disorders in the welders, decreasing exposure time, reducing UV radiation level, and using personal protective equipment seem indispensable. As exposure to UV radiation can be linked to different types of skin cancer, skin aging, and cataract, welders should be advised to decrease their occupational exposures. PMID:26900437

Comparison of Highly Resolved Model-Based Exposure ...

EPA Pesticide Factsheets

Human exposure to air pollution in many studies is represented by ambient concentrations from space-time kriging of observed values. Space-time kriging techniques based on a limited number of ambient monitors may fail to capture the concentration from local sources. Further, because people spend more time indoors, using ambient concentration to represent exposure may cause error. To quantify the associated exposure error, we computed a series of six different hourly-based exposure metrics at 16,095 Census blocks of three Counties in North Carolina for CO, NOx, PM2.5, and elemental carbon (EC) during 2012. These metrics include ambient background concentration from space-time ordinary kriging (STOK), ambient on-road concentration from the Research LINE source dispersion model (R-LINE), a hybrid concentration combining STOK and R-LINE, and their associated indoor concentrations from an indoor infiltration mass balance model. Using a hybrid-based indoor concentration as the standard, the comparison showed that outdoor STOK metrics yielded large error at both population (67% to 93%) and individual level (average bias between −10% to 95%). For pollutants with significant contribution from on-road emission (EC and NOx), the on-road based indoor metric performs the best at the population level (error less than 52%). At the individual level, however, the STOK-based indoor concentration performs the best (average bias below 30%). For PM2.5, due to the relatively low co

Heart rate variability and DNA methylation levels are altered after short-term metal fume exposure among occupational welders: a repeated-measures panel study.

PubMed

Fan, Tianteng; Fang, Shona C; Cavallari, Jennifer M; Barnett, Ian J; Wang, Zhaoxi; Su, Li; Byun, Hyang-Min; Lin, Xihong; Baccarelli, Andrea A; Christiani, David C

2014-12-16

In occupational settings, boilermakers are exposed to high levels of metallic fine particulate matter (PM2.5) generated during the welding process. The effect of welding PM2.5 on heart rate variability (HRV) has been described, but the relationship between PM2.5, DNA methylation, and HRV is not known. In this repeated-measures panel study, we recorded resting HRV and measured DNA methylation levels in transposable elements Alu and long interspersed nuclear element-1 (LINE-1) in peripheral blood leukocytes under ambient conditions (pre-shift) and right after a welding task (post-shift) among 66 welders. We also monitored personal PM2.5 level in the ambient environment and during the welding procedure. The concentration of welding PM2.5 was significantly higher than background levels in the union hall (0.43 mg/m3 vs. 0.11 mg/m3, p < 0.0001). The natural log of transformed power in the high frequency range (ln HF) had a significantly negative association with PM2.5 exposure (β = -0.76, p = 0.035). pNN10 and pNN20 also had a negative association with PM2.5 exposure (β = -0.16%, p = 0.006 and β = -0.13%, p = 0.030, respectively). PM2.5 was positively associated with LINE-1 methylation [β = 0.79%, 5-methylcytosince (%mC), p = 0.013]; adjusted for covariates. LINE-1 methylation did not show an independent association with HRV. Acute decline of HRV was observed following exposure to welding PM2.5 and evidence for an epigenetic response of transposable elements to short-term exposure to high-level metal-rich particulates was reported.

Lead exposure in Nunavik: from research to action

PubMed Central

Couture, Ariane; Levesque, Benoît; Dewailly, Éric; Muckle, Gina; Déry, Serge; Proulx, Jean-François

2012-01-01

Background In 1999, the Government of Canada regulated the use of lead shot for hunting. Concurrently, the Nunavik Regional Board of Health and Social Services (NRBHSS) was informed of the results of an isotope study that pointed to lead ammunition as a likely source of lead exposure in Nunavik. Rapidly thereafter, a coalition for the banning of lead shot was implemented by the NRBHSS as well as by regional/local partners and by Inuit hunters in order to disseminate this information to the public. Objectives The purpose of this article is to describe the intervention conducted in the winter of 1999 by the NRBHSS and to assess the combined impact of national legislation and an awareness campaign on blood lead levels in Nunavik. Study design Impact assessment of the intervention for the banning of lead shot conducted in 1999 in Nunavik using blood lead levels data before and after the intervention. Methods Data on blood lead levels in Nunavik describing foetal exposure as well as during childhood and in adults published between 1992 and 2009 were compiled. Blood lead levels in Nunavik prior to and after the interventions were compared. To assess the current situation, the most recent blood lead levels were compared with those from surveys conducted during the same period in North America. Results Analysis of blood samples collected from umbilical cord and from adults show that blood lead levels in Nunavik significantly declined between 1992 and 2004. Nevertheless, lead exposure in Nunavik still remains higher in comparison to that observed in other North American surveys. Conclusions The current situation regarding lead exposure in Nunavik has significantly improved as a result of the implemented intervention. However, according to recent data, a gap still subsists relative to other North American populations. PMID:22818717

Surrounding Greenness and Exposure to Air Pollution During Pregnancy: An Analysis of Personal Monitoring Data

PubMed Central

de Nazelle, Audrey; Triguero-Mas, Margarita; Schembari, Anna; Cirach, Marta; Amoly, Elmira; Figueras, Francesc; Basagaña, Xavier; Ostro, Bart; Nieuwenhuijsen, Mark

2012-01-01

Background: Green spaces are reported to improve health status, including beneficial effects on pregnancy outcomes. Despite the suggestions of air pollution–related health benefits of green spaces, there is no available evidence on the impact of greenness on personal exposure to air pollution. Objectives: We investigated the association between surrounding greenness and personal exposure to air pollution among pregnant women and to explore the potential mechanisms, if any, behind this association. Methods: In total, 65 rounds of sampling were carried out for 54 pregnant women who resided in Barcelona during 2008–2009. Each round consisted of a 2-day measurement of particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5) and a 1-week measurement of nitric oxides collected simultaneously at both the personal and microenvironmental levels. The study participants were also asked to fill out a time–microenvironment–activity diary during the sampling period. We used satellite retrievals to determine the surrounding greenness as the average of Normalized Difference Vegetation Index (NDVI) in a buffer of 100 m around each maternal residential address. We estimated the impact of surrounding greenness on personal exposure levels, home-outdoor and home-indoor pollutant levels, and maternal time-activity. Results: Higher residential surrounding greenness was associated with lower personal, home-indoor, and home-outdoor PM2.5 levels, and more time spent at home-outdoor. Conclusions: We found lower levels of personal exposure to air pollution among pregnant women residing in greener areas. This finding may be partly explained by lower home-indoor pollutant levels and more time spent in less polluted home-outdoor environment by pregnant women in greener areas. PMID:22647671

Allergens in Urban Schools and Homes of Children with Asthma

PubMed Central

Permaul, Perdita; Hoffman, Elaine B.; Fu, Chunxia; Sheehan, William J.; Baxi, Sachin N.; Gaffin, Jonathan M.; Lane, Jeffrey P.; Bailey, Ann; King, Eva; Chapman, Martin D.; Gold, Diane R.; Phipatanakul, Wanda

2012-01-01

Background Most studies of indoor allergens have focused on the home environment. However, schools may be an important site of allergen exposure for children with asthma. We compared school allergen exposure to home exposure in a cohort of children with asthma. Correlations between settled dust and airborne allergen levels in classrooms were examined. Methods Settled dust and airborne samples from 12 inner-city schools were analyzed for indoor allergens using multiplex array technology (MARIA). School samples were linked to students with asthma enrolled in the School Inner-City Asthma Study (SICAS). Settled dust samples from students’ bedrooms were analyzed similarly. Results From schools, 229 settled dust and 197 airborne samples were obtained. From homes, 118 settled dust samples were obtained. Linear mixed regression models of log-transformed variables showed significantly higher settled dust levels of mouse, cat and dog allergens in schools than homes (545% higher for Mus m 1, estimated absolute difference 0.55 μg/g, p<0.0001; 198% higher for Fel d 1, estimated absolute difference 0.13 μg/g, p=0.0033; and 144% higher for Can f 1, estimated absolute difference 0.05 μg/g, p=0.0008). Airborne and settled dust Mus m 1 levels in classrooms were moderately correlated (r=0.48; p< 0.0001). There were undetectable to very low levels of cockroach and dust mite allergens in both homes and schools. Conclusions Mouse allergen levels in schools were substantial. In general, cat and dog allergen levels were low, but detectable, and were higher in schools. Aerosolization of mouse allergen in classrooms may be a significant exposure for students. Further studies are needed to evaluate the effect of indoor allergen exposure in schools on asthma morbidity in students with asthma. PMID:22672325

Predictors of urinary flame retardant concentration among pregnant women

PubMed Central

Hoffman, Kate; Lorenzo, Amelia; Butt, Craig; Adair, Linda; Herring, Amy H.; Stapleton, Heather M.; Daniels, Julie

2016-01-01

Background Organophosphate compounds are commonly used in residential furniture, electronics, and baby products as flame retardants and are also used in other consumer products as plasticizers. Although the levels of exposure biomarkers are generally higher among children and decrease with age, relatively little is known about the individual characteristics associated with higher levels of exposure. Here, we investigate urinary metabolites of several organophosphate flame retardants (PFRs) in a cohort of pregnant women to evaluate patterns of exposure. Methods Pregnant North Carolina women (n=349) provided information on their individual characteristics (e.g. age and body mass index (BMI)) as a part of the Pregnancy Infection and Nutrition Study (2002–2005). Women also provided second trimester urine samples in which six PFR metabolites were measured using mass spectrometry methods. Results PFR metabolites were detected in every urine sample, with BDCIPP, DHPH, ip-PPP and BCIPHIPP detected in >80% of samples. Geometric mean concentrations were higher than what has been reported previously for similarly-timed cohorts. Women with higher pre-pregnancy BMI tended to have higher levels of urinary metabolites. For example, those classified as obese at the start of pregnancy had ip-PPP levels that were 1.52 times as high as normal weight range women (95% confidence interval: 1.23, 1.89). Women without previous children also tended to have higher urinary levels of DPHP, but lower levels of ip-PPP. In addition, we saw strong evidence of seasonal trends in metabolite concentrations (e.g. higher DPHP, BDCIPP, and BCIPHIPP in summer, and evidence of increasing ip-PPP between 2002 and 2005). Conclusions Our results indicate ubiquitous exposure to PFRs among NC women in the early 2000s. Additionally, our work suggests that individual characteristics are related to exposure and that temporal variation, both seasonal and annual, may exist. PMID:27745946

Hippuric Acid Levels in Paint Workers at Steel Furniture Manufacturers in Thailand

PubMed Central

Decharat, Somsiri

2014-01-01

Background The aims of this study were to determine hippuric acid levels in urine samples, airborne toluene levels, acute and chronic neurological symptoms, and to describe any correlation between urinary hippuric acid and airborne toluene. Methods The hippuric acid concentration in the urine of 87 paint workers exposed to toluene at work (exposed group), and 87 nonexposed people (control group) was studied. Study participants were selected from similar factories in the same region. Urine samples were collected at the end of a shift and analyzed for hippuric acid by high performance liquid chromatography. Air samples for the estimation of toluene exposure were collected with diffusive personal samplers and the toluene quantified using gas–liquid chromatography. The two groups were also interviewed and observed about their work practices and health. Results The median of the 87 airborne toluene levels was 55 ppm (range, 12–198 ppm). The median urinary hippuric acid level was 800 mg/g creatinine (range, 90–2547 mg/g creatinine). A statistically significant positive correlation was found between airborne toluene exposure and urine hippuric acid levels (r = 0.548, p < 0.01). Workers with acute symptoms had significantly higher hippuric acid levels than those who did not (p < 0.05). It was concluded that there was a significant correlation between toluene exposure, hippuric acid levels, and health (p < 0.001). Conclusion There appears to be a significant correlation between workers exposure to toluene at work, their urine hippuric acid levels, and resulting symptoms of poor health. Improvements in working conditions and occupational health education are required at these workplaces. There was good correlation between urinary hippuric acid and airborne toluene levels. PMID:25516817

Biological Monitoring of Blood Naphthalene Levels as a Marker of Occupational Exposure to PAHs among Auto-Mechanics and Spray Painters in Rawalpindi

PubMed Central

2011-01-01

Background Routine exposure to chemical contaminants in workplace is a cause for concern over potential health risks to workers. In Pakistan, reports on occupational exposure and related health risks are almost non-existent, which reflects the scarce availability of survey data and criteria for determining whether an unsafe exposure has occurred. The current study was designed to evaluate blood naphthalene (NAPH) levels as an indicator of exposure to polycyclic aromatic hydrocarbons (PAHs) among automobile workshop mechanics (MCs) and car-spray painters (PNs). We further determined the relationship between blood NAPH levels and personal behavioural, job related parameters and various environmental factors that may further be associated with elevated risks of occupational exposures to PAHs. Methods Sixty blood samples (n = 20 for each group i.e. MC, PN and control group) were collected to compare their blood NAPH levels among exposed (MCs and PNs) and un-exposed (control) groups. Samples were analyzed using high pressure liquid chromatography (HPLC). Data regarding demographic aspects of the subjects and their socioeconomic features were collected using a questionnaire. Subjects were also asked to report environmental hygiene conditions of their occupational environment. Results We identified automobile work areas as potential sites for PAHs exposure, which was reflected by higher blood NAPH levels among MCs. Blood NAPH levels ranged from 53.7 to 1980.6 μgL-1 and 54.1 to 892.9 μgL-1 among MCs and PNs respectively. Comparison within each group showed that smoking enhanced exposure risks several fold and both active and passive smoking were among personal parameters that were significantly correlated with log-transformed blood NAPH levels. For exposed groups, work hours and work experience were job related parameters that showed strong associations with the increase in blood NAPH levels. Poor workplace hygiene and ventilation were recognized as most significant predictors related to differences among workplaces that may enhance the extent of exposure to chemical contaminants. Conclusions It appeared that chemical exposure at the workplace may be influenced by multiple environmental factors, but poor workplace hygiene and duration of exposure (long work hours) were the most important factors. Smoking and negligence of workers regarding self protection were among some of the important personal behaviours than can be addressed with better training. There is also a need to improve workplaces hygiene and to rationalize work hours to minimize health risks. Since smoking was an important confounding factor that supplemented most of the actual occupational exposure, a study based on non-smoker subjects is needed to separate out the effects of smoking and other confounding factors that may obscure measurements of actual extent of occupational exposure. PMID:21668991

Socioeconomic inequalities in childhood exposure to secondhand smoke before and after smoke-free legislation in three UK countries

PubMed Central

Moore, Graham F.; Currie, Dorothy; Gilmore, Gillian; Holliday, Jo C.; Moore, Laurence

2012-01-01

Background Secondhand smoke (SHS) exposure is higher among lower socioeconomic status (SES) children. Legislation restricting smoking in public places has been associated with reduced childhood SHS exposure and increased smoke-free homes. This paper examines socioeconomic patterning in these changes. Methods Repeated cross-sectional survey of 10 867 schoolchildren in 304 primary schools in Scotland, Wales and Northern Ireland. Children provided saliva for cotinine assay, completing questionnaires before and 12 months after legislation. Results SHS exposure was highest, and private smoking restrictions least frequently reported, among lower SES children. Proportions of saliva samples containing <0.1 ng/ml (i.e. undetectable) cotinine increased from 31.0 to 41.0%. Although across the whole SES spectrum, there was no evidence of displacement of smoking into the home or increased SHS exposure, socioeconomic inequality in the likelihood of samples containing detectable levels of cotinine increased. Among children from the poorest families, 96.9% of post-legislation samples contained detectable cotinine, compared with 38.2% among the most affluent. Socioeconomic gradients at higher exposure levels remained unchanged. Among children from the poorest families, one in three samples contained >3 ng/ml cotinine. Smoking restrictions in homes and cars increased, although socioeconomic patterning remained. Conclusions Urgent action is needed to reduce inequalities in SHS exposure. Such action should include emphasis on reducing smoking in cars and homes. PMID:22448041

Human biomonitoring of chromium and nickel from an experimental exposure to manual metal arc welding fumes of low and high alloyed steel.

PubMed

Bertram, Jens; Brand, Peter; Schettgen, Thomas; Lenz, Klaus; Purrio, Ellwyn; Reisgen, Uwe; Kraus, Thomas

2015-05-01

The uptake and elimination of metals from welding fumes is currently not fully understood. In the Aachen Workplace Simulation Laboratory (AWSL) it is possible to investigate the impact of welding fumes on human subjects under controlled exposure conditions. In this study, the uptake and elimination of chromium or chromium (VI) respectively as well as nickel was studied in subjects after exposure to the emissions of a manual metal arc welding process using low or high alloyed steel. In this present study 12 healthy male non-smokers, who never worked as welders before, were exposed for 6h to welding fumes of a manual metal arc welding process. In a three-fold crossover study design, subjects were exposed in randomized order to either clean air, emissions from welding low alloyed steel, and emissions from welding high alloyed steel. Particle mass concentration of the exposure aerosol was 2.5mg m(-3). The content of chromium and nickel in the air was determined by analysing air filter samples on a high emission scenario. Urine analysis for chromium and nickel was performed before and after exposure using methods of human biomonitoring. There were significantly elevated chromium levels after exposure to welding fumes from high alloyed steel compared to urinary chromium levels before exposure to high alloyed welding fumes, as well as compared to the other exposure scenarios. The mean values increased from 0.27 µg l(-1) to 18.62 µg l(-1). The results were in good agreement with already existing correlations between external and internal exposure (German exposure equivalent for carcinogenic working materials EKA). The variability of urinary chromium levels was high. For urinary nickel no significant changes could be detected at all. Six-hour exposure to 2.5mg m(-3) high alloyed manual metal arc welding fumes lead to elevated urinary chromium levels far higher (7.11-34.16 µg l(-1)) than the German biological exposure reference value (BAR) of 0.6 µg l(-1) directly after exposure. On the other hand mean urinary nickel concentrations slightly increased, but did not exceed background levels due to lower bioavailability. We could underline with our single exposure experiment that a welding work related chromium exposure can be measured immediately after the work shift, while the same is not possible for nickel exposure due to lower nickel bioavailability. The data provide useful information for real occupational welding work places. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

[Morbidity in a population living close to urban waste incinerator plants in Lazio Region (Central Italy): a retrospective cohort study using a before-after design].

PubMed

Golini, Martina Nicole; Ancona, Carla; Badaloni, Chiara; Bolignano, Andrea; Bucci, Simone; Sozzi, Roberto; Davoli, Marina; Forastiere, Francesco

2014-01-01

the body of evidence on health effects of residential exposure to urban waste incinerators suggests association with reproductive outcomes and some cancers, but the overall evidence is still limited. we evaluated the impact of two incinerators on hospital admissions for respiratory and cardiovascular diseases in a cohort of people living nearby two incineration plants in Lazio Region (Central Italy) using a before-and-after design. the study area was defined as the 7-km radius around the incinerators. People who were resident in the area from 1996 to 2008 were enrolled in a retrospective longitudinal study. All addresses were geocoded. A Lagrangian dispersion model (SPRAY) for PM₁₀ (ng/m³) was used for incinerators exposure assessment. Average annual concentration of background PM₁₀ (μg/m³) was estimated on a regional basis by means of RAMS and FARM models. Both PM₁₀ exposures were estimated at the residential address. All subjects were followed for hospital admissions in the period before (1996-2002) and after (2003-2008) the activation of the plants. The association between exposure to emissions from incinerators and hospitalizations in the two periods was estimated using the multivariate Cox model (for repeated events), adjusting for age, area-level socioeconomic status, distance from industries, traffic roads and highways. An interaction term between the period of follow-up (before or after the activation of the plants) and the exposure levels was used to test the effect of the incinerators. 47,192 subjects resident in the study area were enrolled. No clear association between pollution exposure from incinerators and cause-specific morbidity of residents in highest concentration areas was found when compared to the reference group. However, an effect of PM₁₀ on respiratory diseases and chronic obstructive pulmonary disease was suggested. The effect was due to excesses of hospitalizations for the same causes among men living in highest exposure areas in respect to the reference group (hazard ratio - HR: 1.26; 95%CI 0.99-1.60, and HR: 1.86; 95%CI 1.04-3.33, respectively). There were associations between exposure to background pollution from other sources and hospitalizations for diseases of the circulatory system (HR: 1.08; 95%CI 1.03-1.13) and respiratory diseases (HR: 1.07; 95%CI 1.02-1.11) (for a unitary increment of PM₁₀, μg/m³). living in areas with high PM₁₀ levels due to incinerators was associated with increased morbidity levels for respiratory disorders among men. The study area is critical from an environmental point of view, hence an epidemiological surveillance is recommended.

Increased risk of chronic obstructive pulmonary diseases in coke oven workers: interaction between occupational exposure and smoking

PubMed Central

Hu, Y; Chen, B; Yin, Z; Jia, L; Zhou, Y; Jin, T

2006-01-01

Background Coke oven workers are regularly exposed to coke oven emissions (COE) and may be at risk of developing lung diseases. There is limited evidence for the link between exposure to COE and chronic obstructive pulmonary diseases (COPD). The aim of this study was to explore the dose‐response relationship between COE exposure and COPD and to assess the interaction with cigarette smoking. Methods Seven hundred and twelve coke oven workers and 211 controls were investigated in southern China. Benzene soluble fraction (BSF) concentrations as a surrogate of COE were measured in representative personal samples and the individual cumulative COE exposure level was quantitatively estimated. Detailed information on smoking habits and respiratory symptoms was collected and spirometric tests were performed. Results The mean BSF levels at the top of two coking plants were 743.8 and 190.5 μg/m3, respectively, which exceed the OSHA standard (150 μg/m3). After adjusting for cigarette smoking and other risk factors, there was a significant dose‐dependent reduction in lung function and increased risks of chronic cough/phlegm and COPD in coke oven workers. The odds ratio for COPD was 5.80 (95% confidence interval 3.13 to 10.76) for high level cumulative COE exposure (⩾1714.0 μg/m3‐years) compared with controls. The interaction between COE exposure and smoking in COPD was significant. The risk of COPD in those with the highest cumulative exposure to COE and cigarette smoking was 58‐fold compared with non‐smokers not exposed to COE. Conclusion Long term exposure to COE increases the risk of an interaction between COPD and cigarette smoking. PMID:16467069

Assessment of potential effects of the electromagnetic fields of mobile phones on hearing

PubMed Central

Uloziene, Ingrida; Uloza, Virgilijus; Gradauskiene, Egle; Saferis, Viktoras

2005-01-01

Background Mobile phones have become indispensable as communication tools; however, to date there is only a limited knowledge about interaction between electromagnetic fields (EMF) emitted by mobile phones and auditory function. The aim of the study was to assess potential changes in hearing function as a consequence of exposure to low-intensity EMF's produced by mobile phones at frequencies of 900 and 1800 MHz. Methods The within-subject study was performed on thirty volunteers (age 18–30 years) with normal hearing to assess possible acute effect of EMF. Participants attended two sessions: genuine and sham exposure of EMF. Hearing threshold levels (HTL) on pure tone audiometry (PTA) and transient evoked otoacoustic emissions (TEOAE's) were recorded before and immediately after 10 min of genuine and/or sham exposure of mobile phone EMF. The administration of genuine or sham exposure was double blind and counterbalanced in order. Results Statistical analysis revealed no significant differences in the mean HTLs of PTA and mean shifts of TEOAE's before and after genuine and/or sham mobile phone EMF 10 min exposure. The data collected showed that average TEOAE levels (averaged across a frequency range) changed less than 2.5 dB between pre- and post-, genuine and sham exposure. The greatest individual change was 10 dB, with a decrease in level from pre- to post- real exposure. Conclusion It could be concluded that a 10-min close exposure of EMFs emitted from a mobile phone had no immediate after-effect on measurements of HTL of PTA and TEOAEs in young human subjects and no measurable hearing deterioration was detected in our study. PMID:15840162

Passive Smoking and Risk of Breast Cancer in the California Teachers Study*†‡

PubMed Central

Reynolds, Peggy; Goldberg, Debbie; Hurley, Susan; Nelson, David O.; Largent, Joan; Henderson, Katherine D.; Bernstein, Leslie

2010-01-01

Background Although recent reviews have suggested active smoking to be a risk factor for breast cancer, the association with passive smoke exposure remains controversial. This risk association was explored in a large prospective study of women, the California Teachers Study. Methods Detailed lifetime information on passive smoke exposure by setting (home, work, or social) and by age of exposure were collected in 1997 from 57,523 women who were lifetime nonsmokers and had no history of breast cancer. In the ensuing decade, a total of 1,754 women were diagnosed with invasive breast cancer. Cox proportional hazards models were fit to estimate hazard ratios (HRs) and 95% confidence intervals (95% CI) associated with several lifetime passive smoke exposure metrics. Results For all breast cancer, measures of higher lifetime passive smoking intensity and duration were associated with non-statistically significant HRs of 1.11 to 1.14. For postmenopausal women, HRs for lifetime low, medium and high cumulative exposure were 1.17 (95%CI 0.91, 1.49), 1.19 (95%CI 0.93, 1.53), and 1.26 (95% CI 0.99, 1.60). For women exposed in adulthood (age ≥20) risk was elevated at the highest level of cumulative exposure (HR=1.18, 95% CI 1.00, 1.40), primarily among postmenopausal women (HR=1.25, 95% CI 1.01, 1.56). A statistically significant dose response was detected when analysis was restricted to women with moderate to high levels of passive smoke exposure. Conclusion These results suggest that cumulative exposures to high levels of side stream smoke may increase breast cancer risk among postmenopausal women who themselves have never smoked tobacco products. PMID:19959687

Single-Nucleotide Polymorphisms Associated with Skin Naphthyl–Keratin Adduct Levels in Workers Exposed to Naphthalene

PubMed Central

Jiang, Rong; French, John E.; Stober, Vandy P.; Kang-Sickel, Juei-Chuan C.; Zou, Fei

2012-01-01

Background: Individual genetic variation that results in differences in systemic response to xenobiotic exposure is not accounted for as a predictor of outcome in current exposure assessment models. Objective: We developed a strategy to investigate individual differences in single-nucleotide polymorphisms (SNPs) as genetic markers associated with naphthyl–keratin adduct (NKA) levels measured in the skin of workers exposed to naphthalene. Methods: The SNP-association analysis was conducted in PLINK using candidate-gene analysis and genome-wide analysis. We identified significant SNP–NKA associations and investigated the potential impact of these SNPs along with personal and workplace factors on NKA levels using a multiple linear regression model and the Pratt index. Results: In candidate-gene analysis, a SNP (rs4852279) located near the CYP26B1 gene contributed to the 2-naphthyl–keratin adduct (2NKA) level. In the multiple linear regression model, the SNP rs4852279, dermal exposure, exposure time, task replacing foam, age, and ethnicity all were significant predictors of 2NKA level. In genome-wide analysis, no single SNP reached genome-wide significance for NKA levels (all p ≥ 1.05 × 10–5). Pathway and network analyses of SNPs associated with NKA levels were predicted to be involved in the regulation of cellular processes and homeostasis. Conclusions: These results provide evidence that a quantitative biomarker can be used as an intermediate phenotype when investigating the association between genetic markers and exposure–dose relationship in a small, well-characterized exposed worker population. PMID:22391508

Impact of environmental tobacco smoke exposure in women on oxidative stress in the antral follicle and assisted reproduction outcomes

PubMed Central

Kazemi, Ashraf; Ramezanzadeh, Fatemeh; Esfahani, Mohammad Hosein Nasr; Saboor-Yaraghi, Ali Akbar; Nejat, Saharnaz; Rahimi-Foroshani, Abbas

2013-01-01

Background: Cigarette smoke contains many oxidants and may alter the human reproduction by inducing oxidative stress (OS) in both active and passive smokers. This study was designed to evaluate the effect of environmental tobacco smoke (ETS) exposure on oxidative stress in the follicular fluid and the assisted reproduction outcomes. Materials and Methods: An observational prospective study was carried out on 236 infertile women, who underwent assisted reproduction cycles. The ETS exposure was assessed using self-reported ETS exposure and the cotinine level in follicular fluid. To evaluate the OS in follicular fluid (FF) malon-di-aldehyde (MDA) and total antioxidant capacity (TAC) were measured. The number of retrieved oocytes, rate of metaphase II stage oocytes, fertilization rate, good cleavage rate, and no-fragmented embryo rate were considered as the assisted reproduction outcomes. The results were adjusted for age, body mass index, duration, and etiology of infertility; P-values less than 0.05 were considered significant. Results: The MDA and TAC levels in FF were not related to the self-report number of the weekly ETS exposure and cotinine levels in FF. Also, the number of retrieved oocytes, MII stage oocytes, fertilization rate, good cleavage rate, and no-fragmented embryo rate were not related to the cotinine level and weekly ETS exposure. However, in women whose cotinine levels in FF were lower and equal/above 3.5 ng/ml, the number of retrieved oocytes was higher (12.63 ± .71 vs. 9.28 ± 1.11, P = 0.01). The relationship between the MDA level and cleavage rate (Beta = −18.5, confidence interval-34.9 and-2.1, P < 0.05) was negatively significant and the relationship between the MII stage rate with TAC (Beta = 0.02, confidence interval 0.01 and 0.04, P < 0.05) was positively significant. Conclusion: The ETS exposure may alter the assisted reproduction success by influencing the number of available oocytes. Although, the OS in a follicular environment affect the ability of oocytes to reach the specific cleavage stages at appropriate time intervals, it does not mediate poor-assisted reproduction outcomes due to ETS exposure. PMID:24379845

Methyl Mercury Exposure at Niigata, Japan: Results of Neurological Examinations of 103 Adults

PubMed Central

Maruyama, Kimio; Yorifuji, Takashi; Tsuda, Toshihide; Sekikawa, Tomoko; Nakadaira, Hiroto; Saito, Hisashi

2012-01-01

Background. Large-scale poisonings caused by methyl mercury (MeHg) have occurred in Japan (Minamata in the 1950s and Niigata in the 1960s) and Iraq (in the 1970s). The current WHO neurological risk standard for adult exposure (hair level: 50 μg/g) was based partly on evidence from Niigata which did not consider any cases who were diagnosed later and/or exposed to low level of MeHg (hair mercury level less than 50 μg/g). Methods. Early in the Niigata epidemic in June 1965 there were two extensive surveys. From these two surveys, we examined 103 adults with hair mercury measurement who consulted two medical institutions. We compared the prevalence and the distribution of neurological signs related to MeHg poisoning between exposure categories. Result. We found 48 subjects with neurological signs related to MeHg poisoning who had hair mercury concentration less than 50 μg/g. Among the neurological signs, sensory disturbance of the bilateral distal extremities was observed more frequently, followed by disequilibrium, hearing impairment, and ataxia, in groups with hair MeHg concentration both below 50 μg/g and over 50 μg/g. Conclusion. The present study suggests the possibility that exposure to MeHg at levels below the current WHO limits could cause neurologic signs, in particular, sensory disturbance. PMID:22888201

Blood lead levels of wild Steller's eiders (Polysticta stelleri) and black scoters (Melanitta nigra) in Alaska using a portable blood lead analyzer

USGS Publications Warehouse

Brown, Corrine S.; Luebbert, Joanne; Mulcahy, Daniel M.; Schamber, Jason L.; Rosenberg, Daniel H.

2006-01-01

Sea duck populations are declining in Alaska. The reasons for the decline are not known; environmental lead exposure is one suspected cause. Thirty wild Steller's eider ducks (Polysticta stelleri) and 40 wild black scoter ducks (Melanitta nigra) were tested for blood lead levels using a portable blood lead analyzer (LeadCare; ESA, Inc., Chelmsford, Massachusetts 01824, USA). Sixty-seven and one-tenth percent of the sea ducks had undetectable blood lead levels, 30.0% had values indicating normal or background lead exposure, and 2.9% had values indicating lead exposure. None of the birds had values indicating lead toxicity, and no birds demonstrated clinical signs of toxicity. Birds in areas with higher human population density had higher blood lead levels than those in less densely populated areas. This is the first time a portable blood lead analyzer has been utilized with sea ducks in a field setting. Because it provides immediate results, it is valuable as a screening tool for investigators carrying out surgical procedures on birds in the field as well as establishing baseline blood lead data on sea ducks. Lead exposure does occur in wild sea ducks, and the study indicates that additional research is needed in order to determine the role environmental lead plays in declining sea duck populations.

Weight-of-evidence environmental risk assessment of dumped chemical weapons after WWII along the Nord-Stream gas pipeline in the Bornholm Deep.

PubMed

Sanderson, Hans; Fauser, Patrik; Thomsen, Marianne; Larsen, Jørn Bo

2012-05-15

In connection with installation of two natural gas pipelines through the Baltic Sea between Russia and Germany, there has been concern regarding potential re-suspension of historically dumped chemical warfare agents (CWA) in a nearby dump site and the potential environmental risks associated. 192 sediment and 11 porewater samples were analyzed for CWA residues, both parent and metabolites in 2008 and 2010 along the pipeline corridor next to the dump site. Macrozoobenthos and background variables were also collected and compared to the observed CWA levels and predicted potential risks. Detection frequencies and levels of intact CWA found were low, whereas CWA metabolites were more frequently found. Re-suspension of CWA residue-containing sediment from installation of the pipelines contributes marginally to the overall background CWA residue exposure and risk along the pipeline route. The multivariate weight-of-evidence analysis showed that physical and background parameters of the sediment were of higher importance for the biota than observed CWA levels. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of positive acceleration on the metabolism of endogenous carbon monoxide and serum lipid in atherosclerotic rabbits

PubMed Central

Luo, Huilan; Chen, Yongsheng; Wang, Junhua

2010-01-01

Background: Atherosclerosis (AS) is caused mainly due to the increase in the serum lipid, thrombosis, and injuries of the endothelial cells. During aviation, the incremental load of positive acceleration that leads to dramatic stress reactions and hemodynamic changes may predispose pilots to functional disorders and even pathological changes of organs. However, much less is known on the correlation between aviation and AS pathogenesis. Methods and Results: A total of 32 rabbits were randomly divided into 4 groups with 8 rabbits in each group. The control group was given a high cholesterol diet but no acceleration exposure, whereas the other 3 experimental groups were treated with a high cholesterol diet and acceleration exposure for 4, 8, and 12 weeks, respectively. In each group, samples of celiac vein blood and the aorta were collected after the last exposure for the measurement of endogenous CO and HO-1 activities, as well as the levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). As compared with the control group, the endocardial CO content and the HO-1 activity in aortic endothelial cells were significantly elevated at the 4th, 8th, and 12th weekend, respectively (P < 0.05 or <0.01). And these measures tended upward as the exposure time was prolonged. Levels of TC and LDL-C in the experimental groups were significantly higher than those in the control group, presenting an upward tendency. Levels of TG were found significantly increased in the 8-week-exposure group, but significantly declined in the 12-week-exposure group (still higher than those in the control group). Levels of the HDL-C were increased in the 4-week-exposure group, declined in the 8-week-exposure group, and once more increased in the 12-week-exposure group, without significant differences with the control group. Conclusions: Positive acceleration exposure may lead to a significant increase of endogenous CO content and HO-1 activity and a metabolic disorder of serum lipid in high-cholesterol diet–fed rabbits, which implicates that the acceleration exposure might accelerate the progression of AS. PMID:20877690

Air pollution and subclinical airway inflammation in the SALIA cohort study

PubMed Central

2014-01-01

Background The association between long-term exposure to air pollution and local inflammation in the lung has rarely been investigated in the general population of elderly subjects before. We investigated this association in a population-based cohort of elderly women from Germany. Methods In a follow-up examination of the SALIA cohort study in 2008/2009, 402 women aged 68 to 79 years from the Ruhr Area and Borken (Germany) were clinically examined. Inflammatory markers were determined in exhaled breath condensate (EBC) and in induced sputum (IS). We used traffic indicators and measured air pollutants at single monitoring stations in the study area to assess individual traffic exposure and long-term air pollution background exposure. Additionally long-term residential exposure to air pollution was estimated using land-use regression (LUR) models. We applied multiple logistic and linear regression analyses adjusted for age, indoor mould, smoking, passive smoking and socio-economic status and additionally conducted sensitivity analyses. Results Inflammatory markers showed a high variability between the individuals and were higher with higher exposure to air pollution. NO derivatives, leukotriene (LT) B4 and tumour necrosis factor-α (TNF-α) showed the strongest associations. An increase of 9.42 μg/m3 (interquartile range) in LUR modelled NO2 was associated with measureable LTB4 level (level with values above the detection limit) in EBC (odds ratio: 1.38, 95% CI: 1.02 -1.86) as well as with LTB4 in IS (%-change: 19%, 95% CI: 7% - 32%). The results remained consistent after exclusion of subpopulations with risk factors for inflammation (smoking, respiratory diseases, mould infestation) and after extension of models with additional adjustment for season of examination, mass of IS and urban/rural living as sensitivity analyses. Conclusions In this analysis of the SALIA study we found that long-term exposure to air pollutants from traffic and industrial sources was associated with an increase of several inflammatory markers in EBC and in IS. We conclude that long-term exposure to air pollution might lead to changes in the inflammatory marker profile in the lower airways in an elderly female population. PMID:24645673

Exposure estimates to disinfection by-products of chlorinated drinking water.

PubMed

Weisel, C P; Kim, H; Haltmeier, P; Klotz, J B

1999-02-01

Exposure to disinfection by-products (DBPs) of drinking water is multiroute and occurs in households serviced by municipal water treatment facilities that disinfect the water as a necessary step to halt the spread of waterborne infectious diseases. Biomarkers of the two most abundant groups of DBPs of chlorination, exhaled breath levels of trihalomethanes (THMs) and urinary levels of two haloacetic acids, were compared to exposure estimates calculated from in-home tap water concentrations and responses to a questionnaire related to water usage. Background THM breath concentrations were uniformly low. Strong relationships were identified between the THM breath concentrations collected after a shower and both the THM water concentration and the THM exposure from a shower, after adjusting for the postshower delay time in collecting the breath sample. Urinary haloacetic acid excretion rates were not correlated to water concentrations. Urinary trichloroacetic acid excretion rates were correlated with ingestion exposure, and that correlation was stronger in a subset of individuals who consumed beverages primarily within their home where the concentration measurements were made. No correlation was observed between an average 48-hr exposure estimate and the urinary dichloroacetic acid excretion rate, presumably because of its short biological half-life. Valid biomarkers were identified for DBP exposures, but the time between the exposure and sample collection should be considered to account for different metabolic rates among the DBPs. Further, using water concentration as an exposure estimate can introduce misclassification of exposure for DBPs whose primary route is ingestion due to the great variability in the amount of water ingested across a population.

Mouse allergen exposure, wheeze and atopy in the first seven years of life

PubMed Central

Phipatanakul, W.; Celedón, J. C.; Hoffman, E. B.; Abdulkerim, H.; Ryan, L. M.; Gold, D. R.

2008-01-01

Background Little is known about mouse allergen exposure in home environments and the development of wheezing, asthma and atopy in childhood. Objective To examine the relation between mouse allergen exposure and wheezing, atopy, and asthma in the first 7 years of life. Methods Prospective study of 498 children with parental history of allergy or asthma followed from birth to age 7 years, with longitudinal questionnaire ascertainment of reported mouse exposure and dust sample mouse urinary protein allergen levels measured at age 2–3 months. Results Parental report of mouse exposure in the first year of life was associated with increased risk of transient wheeze and wheezing in early life. Current report of mouse exposure was also significantly associated with current wheeze throughout the first 7 years of life in the longitudinal analysis (P = 0.03 for overall relation of current mouse to current wheeze). However, early life mouse exposure did not predict asthma, eczema or allergic rhinitis at age 7 years. Exposure to detectable levels of mouse urinary protein in house dust samples collected at age 2–3 months was associated with a twofold increase in the odds of atopy (sensitization to >=1 allergen) at school age (95% confidence interval for odds ratio = 1.1–3.7; P = 0.03 in a multivariate analysis. Conclusions Among children with parental history of asthma or allergies, current mouse exposure is associated with increased risk of wheeze during the first 7 years of life. Early mouse exposure was associated with early wheeze and atopy later in life. PMID:18616677

Evaluation of the Human IgG Antibody Response to Aedes albopictus Saliva as a New Specific Biomarker of Exposure to Vector Bites

PubMed Central

Doucoure, Souleymane; Mouchet, François; Cornelie, Sylvie; DeHecq, Jean Sébastien; Rutee, Abdul Hamid; Roca, Yelin; Walter, Annie; Hervé, Jean Pierre; Misse, Dorothée; Favier, François; Gasque, Philippe; Remoue, Franck

2012-01-01

Background The spread of Aedes albopictus, a vector for re-emergent arbovirus diseases like chikungunya and dengue, points up the need for better control strategies and new tools to evaluate transmission risk. Human antibody (Ab) responses to mosquito salivary proteins could represent a reliable biomarker for evaluating human-vector contact and the efficacy of control programs. Methodology/Principal Findings We used ELISA tests to evaluate specific immunoglobulin G (IgG) responses to salivary gland extracts (SGE) in adults exposed to Aedes albopictus in Reunion Island. The percentage of immune responders (88%) and levels of anti-SGE IgG Abs were high in exposed individuals. At an individual level, our results indicate heterogeneity of the exposure to Aedes albopictus bites. In addition, low-level immune cross-reactivity between Aedes albopictus and Aedes aegypti SGEs was observed, mainly in the highest responders. Conclusion/Significance Ab responses to saliva could be used as an immuno-epidemiological tool for evaluating exposure to Aedes albopictus bites. Combined with entomological and epidemiological methods, a “salivary” biomarker of exposure to Aedes albopictus could enhance surveillance of its spread and the risk of arbovirus transmission, and could be used as a direct tool for the evaluation of Aedes albopictus control strategies. PMID:22363823

Moringa oleifera Supplemented Diets Prevented Nickel-Induced Nephrotoxicity in Wistar Rats

PubMed Central

Adeyemi, O. S.; Elebiyo, T. C.

2014-01-01

Background. The Moringa oleifera plant has been implicated for several therapeutic potentials. Objective. To evaluate whether addition of M. oleifera to diet has protective effect against nickel-induced nephrotoxicity in rats. Methodology. Male Wistar rats were assigned into six groups of five. The rats were given oral exposure to 20 mg/kg nickel sulphate (NiSO4) in normal saline and sustained on either normal diet or diets supplemented with Moringa oleifera at different concentrations for 21 days. 24 hours after cessation of treatments, all animals were sacrificed under slight anesthesia. The blood and kidney samples were collected for biochemical and histopathology analyses, respectively. Results. NiSO4 exposure reduced the kidney-to-body weight ratio in rats and caused significant elevation in the levels of plasma creatinine, urea, and potassium. Also, the plasma level of sodium was decreased by NiSO4 exposure. However, addition of M. oleifera to diets averted the nickel-induced alteration to the level of creatinine and urea. The histopathology revealed damaged renal tubules and glomerular walls caused by NiSO4 exposure. In contrast, the damages were ameliorated by the M. oleifera supplemented diets. Conclusion. The addition of M. oleifera to diet afforded significant protection against nickel-induced nephrotoxicity. PMID:25295181

Space Weather and the Ground-Level Solar Proton Events of the 23rd Solar Cycle

NASA Astrophysics Data System (ADS)

Shea, M. A.; Smart, D. F.

2012-10-01

Solar proton events can adversely affect space and ground-based systems. Ground-level events are a subset of solar proton events that have a harder spectrum than average solar proton events and are detectable on Earth's surface by cosmic radiation ionization chambers, muon detectors, and neutron monitors. This paper summarizes the space weather effects associated with ground-level solar proton events during the 23rd solar cycle. These effects include communication and navigation systems, spacecraft electronics and operations, space power systems, manned space missions, and commercial aircraft operations. The major effect of ground-level events that affect manned spacecraft operations is increased radiation exposure. The primary effect on commercial aircraft operations is the loss of high frequency communication and, at extreme polar latitudes, an increase in the radiation exposure above that experienced from the background galactic cosmic radiation. Calculations of the maximum potential aircraft polar route exposure for each ground-level event of the 23rd solar cycle are presented. The space weather effects in October and November 2003 are highlighted together with on-going efforts to utilize cosmic ray neutron monitors to predict high energy solar proton events, thus providing an alert so that system operators can possibly make adjustments to vulnerable spacecraft operations and polar aircraft routes.

Bias magnification in ecologic studies: a methodological investigation

PubMed Central

Webster, Thomas F

2007-01-01

Background As ecologic studies are often inexpensive to conduct, consideration of the magnitude and direction of ecologic biases may be useful in both study design and sensitivity analysis of results. This paper examines three types of ecologic bias: confounding by group, effect measure modification by group, and non-differential exposure misclassification. Methods Bias of the risk difference on the individual and ecologic levels are compared using two-by-two tables, simple equations, and risk diagrams. Risk diagrams provide a convenient way to simultaneously display information from both levels. Results Confounding by group and effect measure modification by group act in the same direction on the individual and group levels, but have larger impact on the latter. The reduction in exposure variance caused by aggregation magnifies the individual level bias due to ignoring groups. For some studies, the magnification factor can be calculated from the ecologic data alone. Small magnification factors indicate little bias beyond that occurring at the individual level. Aggregation is also responsible for the different impacts of non-differential exposure misclassification on individual and ecologic studies. Conclusion The analytical tools developed here are useful in analyzing ecologic bias. The concept of bias magnification may be helpful in designing ecologic studies and performing sensitivity analysis of their results. PMID:17615079

Flaxseed Mitigates Acute Oxidative Lung Damage in a Mouse Model of Repeated Radiation and Hyperoxia Exposure Associated with Space Exploration

PubMed Central

Pietrofesa, Ralph A.; Solomides, Charalambos C.; Christofidou-Solomidou, Melpo

2015-01-01

Background Spaceflight missions may require crewmembers to conduct extravehicular activities (EVA). Pre-breathe protocols in preparation for an EVA entail 100% hyperoxia exposure that may last for a few hours and be repeated 2-3 times weekly. Each EVA is associated with additional challenges such as low levels of total body cosmic/galactic radiation exposure that may present a threat to crewmember health. We have developed a mouse model of total body radiation and hyperoxia exposure and identified acute damage of lung tissues. In the current study we evaluated the usefulness of dietary flaxseed (FS) as a countermeasure agent for such double-hit exposures. Methods We evaluated lung tissue changes 2 weeks post-initiation of exposure challenges. Mouse cohorts (n=5/group) were pre-fed diets containing either 0% FS or 10% FS for 3 weeks and exposed to: a) normoxia (Untreated); b) >95% O2 (O2); c) 0.25Gy single fraction gamma radiation (IR); or d) a combination of O2 and IR (O2+IR) 3 times per week for 2 consecutive weeks, where 8-hour hyperoxia treatments were spanned by normoxic intervals. Results At 2 weeks post challenge, while control-diet fed mice developed significant lung injury and inflammation across all challenges, FS protected lung tissues by decreasing bronchoalveolar lavage fluid (BALF) neutrophils (p<0.003) and protein levels, oxidative tissue damage, as determined by levels of malondialdehyde (MDA) (p<0.008) and nitrosative stress as determined by nitrite levels. Lung hydroxyproline levels, a measure of lung fibrosis, were significantly elevated in mice fed 0% FS (p<0.01) and exposed to hyperoxia/radiation or the combination treatment, but not in FS-fed mice. FS also decreased levels of a pro-inflammatory, pro-fibrogenic cytokine (TGF-β1) gene expression levels in lung. Conclusion Flaxseed mitigated adverse effects in lung of repeat exposures to radiation/hyperoxia. This data will provide useful information in the design of countermeasures to early tissue oxidative damage associated with space exploration. PMID:25705570

Spectral determinations for discrete sources with EGRET

NASA Technical Reports Server (NTRS)

Hughes, E. B.; Nolan, P. L.

1990-01-01

The ability of the EGRET (Energetic Gamma-Ray Experimental Telescope) to determine the spectral parameters of point sources in 14-day exposures, as planned for the initial survey phase of the GRO (Gamma Ray Observatory) mission, is explored by numerical simulation. Results are given for both galactic and extragalactic objects as a function of source strength and for representative levels of diffuse background emission.

Effect of Environmental Exposure to Lead and Tobacco Smoke on Inattentive and Hyperactive Symptoms and Neurocognitive Performance in Children

ERIC Educational Resources Information Center

Cho, Soo-Churl; Kim, Boong-Nyun; Hong, Yun-Chul; Shin, Min-Sup; Yoo, Hee Jeong; Kim, Jae-Won; Bhang, Soo-Young; Cho, In Hee; Kim, Hyo-Won

2010-01-01

Background: The present study assessed the association between blood lead and urinary cotinine levels and inattentive and hyperactive symptoms and neurocognitive performance in children. Methods: A total of 667 children (age range 8-11) were recruited from nine schools in five Korean cities. The teachers and parents completed the Korean version of…

Investigation of background radiation levels and geologic unit profiles in Durango, Colorado

DOE Office of Scientific and Technical Information (OSTI.GOV)

Triplett, G.H.; Foutz, W.L.; Lesperance, L.R.

1989-11-01

As part of the Uranium Mill Tailings Remedial Action (UMTRA) Project, Oak Ridge National Laboratory (ORNL) has performed radiological surveys on 435 vicinity properties (VPs) in the Durango area. This study was undertaken to establish the background radiation levels and geologic unit profiles in the Durango VP area. During the months of May through June, 1986, extensive radiometric measurements and surface soil samples were collected in the Durango VP area by personnel from ORNL's Grand Junction Office. A majority of the Durango VP surveys were conducted at sites underlain by Quaternary alluvium, older Quaternary gravels, and Cretaceous Lewis and Mancosmore » shales. These four geologic units were selected to be evaluated. The data indicated no formation anomalies and established regional background radiation levels. Durango background radionuclide concentrations in surface soil were determined to be 20.3 {plus minus} 3.4 pCi/g for {sup 40}K, 1.6 {plus minus} 0.5 pCi/g for {sup 226}Ra, and 1.2 {plus minus} 0.3 pCi/g for {sup 232}Th. The Durango background gamma exposure rate was found to be 16.5 {plus minus} 1.3 {mu}R/h. Average gamma spectral count rate measurements for {sup 40}K, {sup 226}Ra and {sup 232}Th were determined to be 553, 150, and 98 counts per minute (cpm), respectively. Geologic unit profiles and Durango background radiation measurements are presented and compared with other areas. 19 refs., 15 figs., 5 tabs.« less

Children’s Patterns of Emotional Reactivity to Conflict as Explanatory Mechanisms in Links Between Interpartner Aggression and Child Physiological Functioning

PubMed Central

Davies, Patrick T.; Sturge-Apple, Melissa L.; Cicchetti, Dante; Manning, Liviah G.; Zale, Emily

2009-01-01

Background This paper examined children’s fearful, sad, and angry reactivity to interparental conflict as mediators of associations between their exposure to interparental aggression and physiological functioning. Methods Participants included 200 toddlers and their mothers. Assessments of interparental aggression and children’s emotional reactivity were derived from maternal surveys and a semi-structured interview. Cortisol levels and cardiac indices of sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) activity were used to assess toddler physiological functioning. Results Results indicated that toddler exposure to interparental aggression was associated with greater cortisol levels and PNS activity and diminished SNS activity. Toddler angry emotional reactivity mediated associations between interparental aggression and cortisol and PNS functioning. Fearful emotional reactivity was a mediator of the link between interparental aggression and SNS functioning. Conclusions The results are interpreted within conceptualizations of how exposure and reactivity to family risk organizing individual differences in physiological functioning. PMID:19744183

Organophosphorus flame retardants and plasticizers in marine and fresh water biota and in human milk.

PubMed

Sundkvist, Anneli Marklund; Olofsson, Ulrika; Haglund, Peter

2010-04-01

The levels and relative proportions of 11 organophosphorus flame retardants and plasticizers (OPs), some of which are reportedly toxic to aquatic organisms, were investigated in human breast milk and samples of fish and mussels from Swedish lakes and coastal areas in order to assess spatial differences in environmental exposure and spatial and temporal differences in human exposure. Some of the biota samples were collected at locations with known potential sources of OPs, but most were collected in background locations. Tris-2-chloroisopropyl phosphate (TCPP) and triphenyl phosphate (TPP) dominated in the biota with levels ranging from 170 to 770 ng g(-1) for TCPP in perch and between 21 and 180 ng g(-1) for TPP. In milk samples, TCPP (median 45 ng g(-1)) and tributyl phosphate (median 12 ng g(-1)) were the most frequently occurring OPs. Among samples of fish from background locations, the concentrations and profiles of most OPs were quite similar, indicating that their sources were diffuse. However, in fish from sample locations near known sources, there were marked differences in OP concentrations and profiles. Fish from a stream receiving surface water from Arlanda airport displayed high levels of OPs (10 200 ng g(-1)) that are commonly used in aircraft hydraulic fluids. Fish collected at points 1 or 2 km downstream of sewage treatment plants showed significantly higher levels of tris(2-butoxyethyl) phosphate (TBEP), one of the most typically abundant OP in effluents from such plants. In the milk samples obtained from women in different towns no distinct differences were detected in OP concentrations or profiles. However, the levels of TBEP tended to be higher in milk collected 10 years ago than in milk collected more recently. However, human exposure to OPs through eating fish or to breastfeeding babies seems to be of minor importance in relation to other potential sources, such as indoor dust inhalation and ingestion.

Urinary Porphyrin Excretion in Neurotypical and Autistic Children

PubMed Central

Woods, James S.; Armel, Sarah E.; Fulton, Denise I.; Allen, Jason; Wessels, Kristine; Simmonds, P. Lynne; Granpeesheh, Doreen; Mumper, Elizabeth; Bradstreet, J. Jeffrey; Echeverria, Diana; Heyer, Nicholas J.; Rooney, James P.K.

2010-01-01

Background Increased urinary concentrations of pentacarboxyl-, precopro- and copro-porphyrins have been associated with prolonged mercury (Hg) exposure in adults, and comparable increases have been attributed to Hg exposure in children with autism (AU). Objectives This study was designed to measure and compare urinary porphyrin concentrations in neurotypical (NT) children and same-age children with autism, and to examine the association between porphyrin levels and past or current Hg exposure in children with autism. Methods This exploratory study enrolled 278 children 2–12 years of age. We evaluated three groups: AU, pervasive developmental disorder-not otherwise specified (PDD-NOS), and NT. Mothers/caregivers provided information at enrollment regarding medical, dental, and dietary exposures. Urine samples from all children were acquired for analyses of porphyrin, creatinine, and Hg. Differences between groups for mean porphyrin and Hg levels were evaluated. Logistic regression analysis was conducted to determine whether porphyrin levels were associated with increased risk of autism. Results Mean urinary porphyrin concentrations are naturally high in young children and decline by as much as 2.5-fold between 2 and 12 years of age. Elevated copro- (p < 0.009), hexacarboxyl- (p < 0.01) and pentacarboxyl- (p < 0.001) porphyrin concentrations were significantly associated with AU but not with PDD-NOS. No differences were found between NT and AU in urinary Hg levels or in past Hg exposure as determined by fish consumption, number of dental amalgam fillings, or vaccines received. Conclusions These findings identify disordered porphyrin metabolism as a salient characteristic of autism. Hg exposures were comparable between diagnostic groups, and a porphyrin pattern consistent with that seen in Hg-exposed adults was not apparent. PMID:20576582

Allergen exposure modifies the relation of sensitization to FENO levels in children at risk for allergy and asthma

PubMed Central

Sordillo, Joanne E; Webb, Tara; Kwan, Doris; Kamel, Jimmy; Hoffman, Elaine; Milton, Donald K; Gold, Diane R

2011-01-01

Background Studies on airway inflammation, measured as fraction exhaled nitric oxide (FENO), have focused on its relation to control of asthma, but the contribution of allergen exposure to elevation of FENO is unknown. Objective We evaluated (1) whether FENO was elevated in children with allergic sensitization or asthma; (2) whether specific allergen exposure increased FENO levels in sensitized, but not in unsensitized children; and (3) whether sedentary behavior increased FENO, independent of allergen exposures. Methods At age 12, in a birth cohort of children with parental history of allergy or asthma, we measured bed dust allergen (dust mite, cat, cockroach) by ELISA; specific allergic sensitization primarily by specific IgE ; and respiratory disease (current asthma, rhinitis, and wheeze) and hours of TV viewing/video game playing by questionnaire. Children performed spirometry maneuvers before and after bronchodilator responses, and had FENO measured using electrochemical detection methods (NIOX MINO). Results FENO was elevated in children with current asthma (32.2 ppb), wheeze (27.0 ppb), or rhinitis (23.2ppb) as compared to individuals without these respective symptoms/diagnoses (16.4 ppb to 16.6 ppb, p< 0.005 for all comparisons). Allergic sensitization to indoor allergens (cat, dog, dust mite) predicted higher levels of FENO, and explained one third of the variability of FENO. FENO levels were highest in children both sensitized and exposed to dust mite. Greater than 10 hours of weekday TV viewing was associated with a 0.64 log increase in FENO, after controlling indoor allergen exposure, BMI and allergic sensitization. Conclusion Allergen exposures and sedentary behavior (TV viewing/ video game playing), may increase airway inflammation, measured as FENO. PMID:21463890

Providing the Missing Link: the Exposure Science Ontology ...

EPA Pesticide Factsheets

Although knowledge-discovery tools are new to the exposure science community, these tools are critical for leveraging exposure information to design health studies and interpret results for improved public health decisions. Standardized ontologies define relationships, allow for automated reasoning, and facilitate meta-analyses. ExO will facilitate development of biologically relevant exposure metrics, design of in vitro toxicity tests, and incorporation of information on susceptibility and background exposures for risk assessment. In this approach, there are multiple levels of organization, from the global environment down through ecosystems, communities, indoor spaces, populations, organisms, tissues, and cells. We anticipate that the exposure science and environmental health community will adopt and contribute to this work, as wide acceptance is key to integration and federated searching of exposure data to support environmental and public health research. In particular, we anticipate acceptance of the concept that exposure science provides the spatial/temporal narrative about the intensity (concentration) of a stressor at the boundary between two systems: one functioning as an “environment” (stressor) and one functioning as a target (receptor). An agreed-upon exposure ontology with clear definitions and relationships should help to facilitate decision-making, study design and prioritization of research initiatives by enhancing the capacity for data colle

Impact of time-activity patterns on personal exposure to black carbon

NASA Astrophysics Data System (ADS)

Dons, Evi; Int Panis, Luc; Van Poppel, Martine; Theunis, Jan; Willems, Hanny; Torfs, Rudi; Wets, Geert

2011-07-01

Time-activity patterns are an important determinant of personal exposure to air pollution. This is demonstrated by measuring personal exposure of 16 participants for 7 consecutive days: 8 couples of which one person was a full-time worker and the other was a homemaker; both had a very different time-activity pattern. We used portable aethalometers to measure black carbon levels with a high temporal resolution and a PDA with GPS-logger and electronic diary. The exposure to black carbon differs between partners by up to 30%, although they live at the same location. The activity contributing most to this difference is transport: Average exposure in transport is 6445 ng m -3, followed by exposure during shopping (2584 ng m -3). Average exposure is lowest while sleeping (1153 ng m -3) and when doing home-based activities (1223 ng m -3). Full-time workers spend almost twice as much time in transport as the homemakers. As a result of the study design we measured in several different homes, shops, cars, etc. enabling a better insight in true overall exposure in those microenvironments. Other factors influencing personal exposure are: background concentrations and location of residence in an urban, suburban or rural environment.

Determinants of isocyanate exposures in auto body repair and refinishing shops.

PubMed

Woskie, S R; Sparer, J; Gore, R J; Stowe, M; Bello, D; Liu, Y; Youngs, F; Redlich, C; Eisen, E; Cullen, M

2004-07-01

As part of the Survey of Painters and Repairers of Auto bodies by Yale (SPRAY), the determinants of isocyanate exposure in auto body repair shops were evaluated. Measurements (n = 380) of hexamethylene diisocyanate-based monomer and polyisocyanate and isophorone diisocyanate-based polyisocyanate were collected from 33 auto body shops. The median total reactive isocyanate concentrations expressed as mass concentration of the NCO functional group were: 206 microg NCO/m3 for spray operations; 0.93 microg NCO/m3 for samples collected in the vicinity of spray operations done on the shop floor (near spray); 0.05 microg NCO/m3 for office or other shop areas adjacent to spray areas (workplace background); 0.17 microg NCO/m3 for paint mixing and gun cleaning operations (mixing); 0.27 microg NCO/m3 for sanding operations. Exposure determinants for the sample NCO mass load were identified using linear regression, tobit regression and logistic regression models. For spray samples in a spray booth the significant determinants were the number of milliliters of NCO applied, the gallons of clear coat used by the shop each month and the type of spray booth used (custom built crossdraft, prefabricated crossdraft or downdraft/semi-downdraft). For near spray (bystander) samples, outdoor temperature >65 degrees F (18 degrees C) and shop size >5000 feet2 (465 m2) were significant determinants of exposure levels. For workplace background samples the shop annual income was the most important determinant. For sanding samples, the shop annual income and outdoor temperature >65 degrees F (18 degrees C) were the most significant determinants. Identification of these key exposure determinants will be useful in targeting exposure evaluation and control efforts to reduce isocyanate exposures.

Exposure assessment of diesel bus emissions.

PubMed

Yip, Maricela; Madl, Pierre; Wiegand, Aaron; Hofmann, Werner

2006-12-01

The goal of this study was to measure ultrafine particle concentrations with diameters less than 1 mum emitted by diesel buses and to assess resulting human exposure levels. The study was conducted at the Woolloongabba Busway station in Brisbane, Australia in the winter months of 2002 during which temperature inversions frequently occurred. Most buses that utilize the station are fuelled by diesel, the exhaust of which contains a significant quantity of particle matter. Passengers waiting at the station are exposed to these particles emitted from the buses. During the course of this study, passenger census was conducted, based on video surveillance, yielding person-by-person waiting time data. Furthermore, a bus census revealed accurate information about the total number of diesel versus Compressed Natural Gas (CNG) powered buses. Background (outside of the bus station) and platform measurements of ultrafine particulate number size distributions were made to determine ambient aerosol concentrations. Particle number exposure concentration ranges from 10 and 40 to 60% of bus related exhaust fumes. This changes dramatically when considering the particle mass exposure concentration, where most passengers are exposed to about 50 to 80% of exhaust fumes. The obtained data can be very significant for comparison with similar work of this type because it is shown in previous studies that exhaust emissions causes cancer in laboratory animals. It was assumed that significant differences between platform and background distributions were due to bus emissions which, combined with passenger waiting times, yielded an estimate of passenger exposure to ultrafine particles from diesel buses. From an exposure point of view, the Busway station analyzed resembles a street canyon. Although the detected exhaust particle concentration at the outbound platform is found to be in the picogram range, exposure increases with the time passengers spend on the platform along with their breathing frequency.

BOOK REVIEW: NCRP Report No. 160: Ionizing Radiation Exposure of the Population of the United States NCRP Report No. 160: Ionizing Radiation Exposure of the Population of the United States

NASA Astrophysics Data System (ADS)

Thurston, Jim

2010-10-01

This report by Committee 6 of the Council is an extensive update of a previous report on the exposure of the US population to ionizing radiation sources from data gathered in the 1980s (published as Report 93 in 1987). It is combined with an update on the more in-depth assessment of data on medical exposures previously reported in 1989 (Report 100). Individual chapters in this new report are dedicated to specific sources of exposure to the US population—both from natural and artificial radiation—and the level of detail in each chapter is intended to reflect the significance of the contribution of each source to the total collective dose of the population. The first chapter is on the most significant contributor: background radiation. It expands on the concept of natural background radiation in Report 93, renaming it 'ubiquitous background', and describing in detail the contributions from both extra-terrestrial and terrestrial sources. The data demonstrates that the average dose from such exposure has varied little since the previous report (a slight increase from 3.0 mSv to 3.1 mSv). The next chapter is on medical radiation, i.e. the exposure to the population when attending as patients, not including occupational exposure to hospital workers. The most striking data published in the entire report is the increase in the contribution to the total US population dose attributed to such medical exposures. It is now as significant as that from background radiation: medical exposures now account for an average effective dose to the US citizen of 3.00 mSv, up from 0.53 mSv in 1992 (Report 100). The most important contribution to this increase is the 1.46 mSv from CT scanning alone. The nuclear medicine (including PET) contribution is up from 0.14 mSv to 0.77mSv. This evidently must be due to significant changes in medical radiological practice in the US tied to the increase in the availability of CT and PET imaging facilities. These increasing contributions have driven the overall average effective dose to a US citizen from approximately 3.6 mSv reported in 1987 to 6.2 mSv per annum, with medical exposures now responsible for 48% of the total (up from 15% in 1992). It is interesting to note that over roughly the same period of time, the total dose to the UK population has been revised upwards from 2.6 mSv to 2.7mSv to reflect (amongst other factors) the increase in CT scanning in the UK—obviously a much smaller change. However, one has to consider whether medical radiological practices in the UK might similarly change in the coming years, and UK population doses subsequently follow the US trend reported here. There is now a more detailed chapter on exposure to the population from consumer products and activities. Of the contributing factors in this category, the radiation dose received from radioactivity in tobacco smoke is the most significant, followed by building materials and air travel. There has been no significant change in the total dose received from these sources when compared to the earlier Report 93, at 0.13 mSv. The report also gives significant detail on exposure to the public from industrial sources (not just nuclear power), and discusses occupational exposure. Both these categories of exposure, averaged out of the whole population, give very small contributions to the total dose (0.003 mSv and 0.005 mSv, respectively). There are two final points to make about this report. Firstly, it continues the NCRP policy introduced for Report 93 of using SI units rather than the radiation units more commonly used within the US, hence making this report more readily accessible to an international audience. Secondly, in all the descriptions of the exposures and radiation doses received, no attempt is made to convert the doses into risk. The view of the Council, as stated in the forward to the report, is that attempting to quantify the risks associated with such levels of radiation exposure falls outside the remit of the Committee that prepared the report.

The Relationship between Brand-Specific Alcohol Advertising on Television and Brand-Specific Consumption among Underage Youth

PubMed Central

Ross, Craig S.; Maple, Emily; Siegel, Michael; DeJong, William; Naimi, Timothy S.; Ostroff, Joshua; Padon, Alisa A.; Borzekowski, Dina L.G.; Jernigan, David H.

2014-01-01

Background Being able to investigate the relationship between underage drinkers' preferences for particular brands and their exposure to advertising for those brands would represent a significant advance in alcohol marketing research. However, no previous national study has examined the relationship between underage youth exposure to brand-specific alcohol advertising and consumption of those brands. Methods We conducted a cross-sectional, internet-based survey of a national sample of 1,031 youths, ages 13-20, who had consumed at least one drink of alcohol in the past 30 days. We ascertained all alcohol brands consumed by respondents in the past 30 days. The main outcome measure was brand-specific consumption during the past 30 days, measured as a dichotomous variable. The main predictor variable was exposure to brand-specific alcohol advertising on television. The respondents reported which of 20 television shows popular with youth they had watched during the past 30 days. For each respondent, we calculated a standard measure of potential exposure to the brand-specific alcohol advertising that aired on those shows during the preceding 12 months, based on Nielsen (New York, NY) estimates of the youth audience for each show's telecasts. Results Compared to no brand-specific advertising exposure, any exposure was associated with an increased likelihood of brand-specific consumption (adjusted odds ratio 3.02; 95% confidence interval: 2.61-3.49) after controlling for several individual- and brand-level variables. When measured as a continuous variable, the relationship between advertising exposure and brand consumption was nonlinear, with a large association at lower levels of exposure and diminishing incremental effects as the level of exposure increased. Conclusions There is a robust relationship between youth's brand-specific exposure to alcohol advertising on television and their consumption of those same alcohol brands during the past 30 days. This study provides further evidence of a strong association between alcohol advertising and youth drinking behavior. PMID:24986257

In utero and early childhood exposure to arsenic decreases lung function in children

PubMed Central

Recio-Vega, Rogelio; Gonzalez-Cortes, Tania; Olivas-Calderon, Edgar; Lantz, R. Clark; Gandolfi, A. Jay; Gonzalez-De Alba, Cesar

2016-01-01

Background The lung is a target organ for adverse health outcomes following exposure to arsenic. Several studies have reported a high prevalence of respiratory symptoms and diseases in subjects highly exposed to arsenic through drinking water, however, most studies to date has been performed in exposed adults, with little information on respiratory effects in children. The objective of the study was to evaluate the association between urinary levels of arsenic and its metabolites with lung function in children exposed in utero and in early childhood to high arsenic levels through drinking water. Methods A total of 358 healthy children were included in our study. Individual exposure was assessed based on urinary concentration of inorganic arsenic. Lung function was assessed by spirometry. Results Participants were exposed since pregnancy until early childhood to an average water As concentration of 152.13 μg/L. The mean urinary arsenic level registered in the studied subjects was 141.2 μg/L and only 16.7% had a urinary concentration below the national concern level. Forced vital capacity was significantly decreased in the studied population and it was negatively associated with the percent of inorganic arsenic. More than 57% of the subjects had a restrictive spirometric pattern. The urinary As level was higher in those children with restrictive lung patterns when compared with the levels registered in subjects with normal spirometric patterns. Conclusion Exposure to arsenic through drinking water during in utero and early life was associated with a decrease in FVC and with a restrictive spirometric pattern in the children evaluated. PMID:25131850

Radiation in Yolo County

NASA Astrophysics Data System (ADS)

Dickie, H.; Colwell, K.

2013-12-01

In today's post-nuclear age, there are many man-made sources of radioactivity, in addition to the natural background we expect from cosmic and terrestrial origins. While all atoms possess unstable isotopes, there are few that are abundant enough, energetic enough, and have long enough half-lives to pose a signicant risk of ionizing radiation exposure. We hypothesize a decreasing relative radiation measurement (in detected counts per minute [CPM]) at nine locations that might pose occupational or environmental hazard: 1. A supermarket produce aisle (living tissue has high concentration of 40K) 2. A hospital (medical imaging uses X-rays and radioactive dyes) 3. The electronics section of a superstore (high voltage electronics have the potential to produce ionizing radiation) 4. An electrical transformer (similar reasons) 5. An antique store (some ceramics and glazes use radioisotopes that are now outlawed) 6. A gasoline pump (processing and terrestrial isotope contamination might leave a radioactive residue) 7. A fertilized eld (phosphate rock contains uranium and thorium, in addition to potassium) 8. A house (hopefully mild background, but potential radon contamination) 9. A school (should be radiologically neutral) We tested the hypothesis by measuring 100 minutes of counts on a self-assembled MightyOhmTM Geiger counter at each location. Our results show that contrary to the hypothesized ordering, the house was the most radiologically active. We present possible explanations for the observed radiation levels, as well as possible sources of measurement error, possible consequences of prolonged exposure to the measured levels, and suggestions for decreasing exposure and environmental impact.

Infants' Background Television Exposure during Play: Negative Relations to the Quantity and Quality of Mothers' Speech and Infants' Vocabulary Acquisition

ERIC Educational Resources Information Center

Masur, Elise Frank; Flynn, Valerie; Olson, Janet

2016-01-01

Research on immediate effects of background television during mother-infant toy play shows that an operating television in the room disrupts maternal communicative behaviors crucial for infants' vocabulary acquisition. This study is the first to examine associations between frequent background TV/video exposure during mother-infant toy play at…

Educational background: different processes and consequences on health and physical and mental exposures among women and men.

PubMed

Dahlberg, Raymond; Bildt, Carina; Vingård, Eva; Karlqvist, Lena

2007-01-01

To compare health and exposures at work and at home of women and men with the same educational background. The study group consisted of 3831 individuals, grouped into three educational categories based on length of education. Category 1, which represents 9-year compulsory school; Category 2, which includes 3-year upper secondary school, i.e. in total 12 years of education; and Category 3, which includes post-secondary school, such as university. They responded to a questionnaire that included questions on health and exposures at work and at home. Significant differences were shown in health outcomes between women and men with the same educational background and also in exposures in their professional and private lives. Associations between educational background and health were found and analyses revealed that men with a university education run the lowest risk of developing ill health. Women with the same educational background as men are differently exposed, both in paid and unpaid work, due to the segregated labour market and the unequal distribution of domestic duties. Men in all educational categories studied had better health compared to women with the same educational background.

The Effects of Different Noise Types on Heart Rate Variability in Men

PubMed Central

Sim, Chang Sun; Sung, Joo Hyun; Cheon, Sang Hyeon; Lee, Jang Myung; Lee, Jae Won

2015-01-01

Purpose To determine the impact of noise on heart rate variability (HRV) in men, with a focus on the noise type rather than on noise intensity. Materials and Methods Forty college-going male volunteers were enrolled in this study and were randomly divided into four groups according to the type of noise they were exposed to: background, traffic, speech, or mixed (traffic and speech) noise. All groups except the background group (35 dB) were exposed to 45 dB sound pressure levels. We collected data on age, smoking status, alcohol consumption, and disease status from responses to self-reported questionnaires and medical examinations. We also measured HRV parameters and blood pressure levels before and after exposure to noise. The HRV parameters were evaluated while patients remained seated for 5 minutes, and frequency and time domain analyses were then performed. Results After noise exposure, only the speech noise group showed a reduced low frequency (LF) value, reflecting the activity of both the sympathetic and parasympathetic nervous systems. The low-to-high frequency (LF/HF) ratio, which reflected the activity of the autonomic nervous system (ANS), became more stable, decreasing from 5.21 to 1.37; however, this change was not statistically significant. Conclusion These results indicate that 45 dB(A) of noise, 10 dB(A) higher than background noise, affects the ANS. Additionally, the impact on HRV activity might differ according to the noise quality. Further studies will be required to ascertain the role of noise type. PMID:25510770

The effects of different noise types on heart rate variability in men.

PubMed

Sim, Chang Sun; Sung, Joo Hyun; Cheon, Sang Hyeon; Lee, Jang Myung; Lee, Jae Won; Lee, Jiho

2015-01-01

To determine the impact of noise on heart rate variability (HRV) in men, with a focus on the noise type rather than on noise intensity. Forty college-going male volunteers were enrolled in this study and were randomly divided into four groups according to the type of noise they were exposed to: background, traffic, speech, or mixed (traffic and speech) noise. All groups except the background group (35 dB) were exposed to 45 dB sound pressure levels. We collected data on age, smoking status, alcohol consumption, and disease status from responses to self-reported questionnaires and medical examinations. We also measured HRV parameters and blood pressure levels before and after exposure to noise. The HRV parameters were evaluated while patients remained seated for 5 minutes, and frequency and time domain analyses were then performed. After noise exposure, only the speech noise group showed a reduced low frequency (LF) value, reflecting the activity of both the sympathetic and parasympathetic nervous systems. The low-to-high frequency (LF/HF) ratio, which reflected the activity of the autonomic nervous system (ANS), became more stable, decreasing from 5.21 to 1.37; however, this change was not statistically significant. These results indicate that 45 dB(A) of noise, 10 dB(A) higher than background noise, affects the ANS. Additionally, the impact on HRV activity might differ according to the noise quality. Further studies will be required to ascertain the role of noise type.

Does background postnatal methyl mercury exposure in toddlers affect cognition and behavior?

PubMed

Cao, Yang; Chen, Aimin; Jones, Robert L; Radcliffe, Jerilynn; Caldwell, Kathleen L; Dietrich, Kim N; Rogan, Walter J

2010-01-01

Because the toxicological effects of mercury (Hg) are more serious in the developing central nervous system of children than adults, there are growing concerns about prenatal and early childhood Hg exposure. This study examined postnatal methylmercury (MeHg) exposure and cognition and behavior in 780 children enrolled in the Treatment of Lead (Pb)-exposed Children clinical trial (TLC) with 396 children allocated to the succimer and 384 to the placebo groups. Mercury exposure was determined from analyses of blood drawn 1 week before randomization and 1 week after treatment began when succimer had its maximal effect on blood Pb (PbB). The baseline MeHg concentrations were 0.54 microg/L and 0.52 microg/L and post-treatment concentrations were 0.51 microg/L and 0.48 microg/L for placebo and succimer groups, respectively. Because the baseline characteristics in the two groups were balanced and because succimer had little effect on MeHg concentration and no effect on the cognitive or behavioral test scores, the groups were combined in the analysis of MeHg and neurodevelopment. The children's IQ and neurobehavioral performance were tested at age 2, 5 and 7 years. We saw weak, non-significant but consistently positive associations between blood MeHg and IQ test scores in stratified, spline regression and generalized linear model data analyses. The behavioral problem scores were constant or decreased slightly with increasing MeHg concentration. Additional adjustment for PbB levels in multivariable models did not alter the conclusion for MeHg and IQ scores, but did confirm that concurrent PbB was strongly associated with IQ and behavior in TLC children. The effects of MeHg on neurodevelopmental indices did not substantially differ by PbB strata. We conclude that at the present background postnatal MeHg exposure levels of US children, adverse effects on children's IQ and behavior are not detectable. 2009 Elsevier Inc. All rights reserved.

Associations Between Selected Xenobiotics and Antinuclear Antibodies in the National Health and Nutrition Examination Survey, 1999-2004.

PubMed

Dinse, Gregg E; Jusko, Todd A; Whitt, Irene Z; Co, Caroll A; Parks, Christine G; Satoh, Minoru; Chan, Edward K L; Rose, Kathryn M; Walker, Nigel J; Birnbaum, Linda S; Zeldin, Darryl C; Weinberg, Clarice R; Miller, Frederick W

2016-04-01

Potential associations between background environmental chemical exposures and autoimmunity are understudied. Our exploratory study investigated exposure to individual environmental chemicals and selected mixtures in relation to the presence of antinuclear antibodies (ANA), a widely used biomarker of autoimmunity, in a representative sample of the U.S. This cross-sectional analysis used data on 4,340 participants from the National Health and Nutrition Examination Survey (1999-2004), of whom 14% were ANA positive, to explore associations between ANA and concentrations of dioxins, dibenzofurans, polychlorinated biphenyls, organochlorines, organophosphates, phenols, metals, and other environmental exposures and metabolites measured in participants' serum, whole blood, or urine. For dioxin-like compounds with toxic equivalency factors, we developed and applied a new statistical approach to study selected mixtures. Lognormal models and censored-data methods produced estimates of chemical associations with ANA in males, nulliparous females, and parous females; these estimates were adjusted for confounders and accommodated concentrations below detectable levels. Several associations between chemical concentration and ANA positivity were observed, but only the association in males exposed to triclosan remained statistically significant after correcting for multiple comparisons (mean concentration ratio = 2.8; 95% CI: 1.8, 4.5; p < 0.00001). These data suggest that background levels of most xenobiotic exposures typical in the U.S. population are not strongly associated with ANA. Future studies should ideally reduce exposure misclassification by including prospective measurement of the chemicals of concern and should track changes in ANA and other autoantibodies over time. Dinse GE, Jusko TA, Whitt IZ, Co CA, Parks CG, Satoh M, Chan EKL, Rose KM, Walker NJ, Birnbaum LS, Zeldin DC, Weinberg CR, Miller FW. 2016. Associations between selected xenobiotics and antinuclear antibodies in the National Health and Nutrition Examination Survey, 1999-2004. Environ Health Perspect 124:426-436; http://dx.doi.org/10.1289/ehp.1409345.

Effects of low-dose radiation - a correlation study.

PubMed

Edling, C; Comba, P; Axelson, O; Flodin, U

1982-01-01

The effects of low-dose radiation have been a matter of controversy over the years, and the epidemiologic results have been conflicting. A couple of recent studies have indicated a possible impact on lung cancer mortality from exposure to indoor levels of radon and radon daughters. In this study, selected mortality rates, ie, lung cancer, pancreatic cancer, breast cancer (females only), leukemia, and multiple myeloma were correlated for the counties of Sweden with estimates of average background radiation exposure in these areas. Significant correlations were obtained for lung cancer (males, r = 0.46; females r = 0.55) and pancreatic cancer (males, r = 0.59; females, r = 0.40) , and there was a borderline correlation (r = 0.36; p = 0.04) for leukemia in males. In all, there were positive correlations for eight out of the nine computations made. Since background radiation correlates with urbanization and therefore with smoking, air pollution, etc, the correlations might be spurious due to confounding; on the other hand confounding is a reciprocal phenomenon which suggests that background radiation should to be taken into consideration when widespread risk factors like smoking, coffee drinking, general air pollution, etc, are studied.

Selenium metabolites in urine of cancer patients receiving L-selenomethionine at high doses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuehnelt, Doris; Juresa, Dijana; Francesconi, Kevin A.

2007-04-15

We investigated, with quantitative HPLC/mass spectrometry, the selenium metabolites in urine from five cancer patients receiving high doses of L-selenomethionine over an extended period (2 x 4000 {mu}g Se/day for 7 days, then 4000 {mu}g Se/day for 21 days) as an adjunct to their normal cancer chemotherapy. Urine samples were collected at day 0 (all 5 patients), and at 2-3 additional collection times ranging from 1 to 33 days. The background selenium concentrations ranged from 12 to 55 {mu}g Se/L and increased to 870 to 4420 {mu}g Se/L for the five patients during the study. All five patients had appreciablemore » levels of selenosugars in their background urine sample, and the concentrations increased dramatically after selenium intake. Trimethylselenonium ion (TMSe), on the other hand, was generally present as only a trace metabolite in background urine, and, although the concentration of TMSe increased following selenium exposure, it became a less significant proportion relative to selenosugars. These data refute the currently accepted role of TMSe as the preferred excretion metabolite when selenium exposure is high.« less

Sunlight exposure and cardiovascular risk factors in the REGARDS study: a cross-sectional split-sample analysis

PubMed Central

2014-01-01

Background Previous research has suggested that vitamin D and sunlight are related to cardiovascular outcomes, but associations between sunlight and risk factors have not been investigated. We examined whether increased sunlight exposure was related to improved cardiovascular risk factor status. Methods Residential histories merged with satellite, ground monitor, and model reanalysis data were used to determine previous-year sunlight radiation exposure for 17,773 black and white participants aged 45+ from the US. Exploratory and confirmatory analyses were performed by randomly dividing the sample into halves. Logistic regression models were used to examine relationships with cardiovascular risk factors. Results The lowest, compared to the highest quartile of insolation exposure was associated with lower high-density lipoprotein levels in adjusted exploratory (−2.7 mg/dL [95% confidence interval: −4.2, −1.2]) and confirmatory (−1.5 mg/dL [95% confidence interval: −3.0, −0.1]) models. The lowest, compared to the highest quartile of insolation exposure was associated with higher systolic blood pressure levels in unadjusted exploratory and confirmatory, as well as the adjusted exploratory model (2.3 mmHg [95% confidence interval: 0.8, 3.8]), but not the adjusted confirmatory model (1.6 mg/dL [95% confidence interval: −0.5, 3.7]). Conclusions The results of this study suggest that lower long-term sunlight exposure has an association with lower high-density lipoprotein levels. However, all associations were weak, thus it is not known if insolation may affect cardiovascular outcomes through these risk factors. PMID:24946776

The Precautionary Principle in the Context of Mobile Phone and Base Station Radiofrequency Exposures

PubMed Central

Dolan, Mike; Rowley, Jack

2009-01-01

Background No health hazard has been established from exposure to radiofrequency fields up to the levels recommended by the International Commission on Non-Ionizing Radiation Protection. However, in response to public concern and the perceived level of scientific uncertainty, there are continuing calls for the application of the precautionary principle to radiofrequency exposures from mobile phones and base stations. Objective We examined the international evolution of calls for precautionary measures in relation to mobile phones and base stations, with particular focus on Australia and the United Kingdom. Results The precautionary principle is difficult to define, and there is no widespread agreement as to how it should be implemented. However, there is a strong argument that precautionary measures should not be implemented in the absence of reliable scientific data and logical reasoning pointing to a possible health hazard. There is also experimental evidence that precautionary advice may increase public concern. Conclusion We argue that conservative exposure standards, technical features that minimize unnecessary exposures, ongoing research, regular review of standards, and availability of consumer information make mobile communications inherently precautionary. Commonsense measures can be adopted by individuals, governments, and industry to address public concern while ensuring that mobile networks are developed for the benefit of society. PMID:19750093

Does Short-Term Exposure to Mobile Phone Base Station Signals Increase Symptoms in Individuals Who Report Sensitivity to Electromagnetic Fields? A Double-Blind Randomized Provocation Study

PubMed Central

Eltiti, Stacy; Wallace, Denise; Ridgewell, Anna; Zougkou, Konstantina; Russo, Riccardo; Sepulveda, Francisco; Mirshekar-Syahkal, Dariush; Rasor, Paul; Deeble, Roger; Fox, Elaine

2007-01-01

Background Individuals with idiopathic environmental illness with attribution to electromagnetic fields (IEI-EMF) believe they suffer negative health effects when exposed to electromagnetic fields from everyday objects such as mobile phone base stations. Objectives This study used both open provocation and double-blind tests to determine if sensitive and control individuals experience more negative health effects when exposed to base station-like signals compared with sham. Methods Fifty-six self-reported sensitive and 120 control participants were tested in an open provocation test. Of these, 12 sensitive and 6 controls withdrew after the first session. The remainder completed a series of double-blind tests. Subjective measures of well-being and symptoms as well as physiological measures of blood volume pulse, heart rate, and skin conductance were obtained. Results During the open provocation, sensitive individuals reported lower levels of well-being in both the global system for mobile communication (GSM) and universal mobile telecommunications system (UMTS) compared with sham exposure, whereas controls reported more symptoms during the UMTS exposure. During double-blind tests the GSM signal did not have any effect on either group. Sensitive participants did report elevated levels of arousal during the UMTS condition, whereas the number or severity of symptoms experienced did not increase. Physiological measures did not differ across the three exposure conditions for either group. Conclusions Short-term exposure to a typical GSM base station-like signal did not affect well-being or physiological functions in sensitive or control individuals. Sensitive individuals reported elevated levels of arousal when exposed to a UMTS signal. Further analysis, however, indicated that this difference was likely to be due to the effect of order of exposure rather than the exposure itself. PMID:18007992

Populations potentially exposed to traffic-related air pollution in seven world cities.

PubMed

Su, Jason G; Apte, Joshua S; Lipsitt, Jonah; Garcia-Gonzales, Diane A; Beckerman, Bernardo S; de Nazelle, Audrey; Texcalac-Sangrador, José Luis; Jerrett, Michael

2015-05-01

Traffic-related air pollution (TRAP) likely exerts a large burden of disease globally, and in many places, traffic is increasing dramatically. The impact, however, of urban form on the portion of population potentially exposed to TRAP remains poorly understood. In this study, we estimate portions of population potentially exposed to TRAP across seven global cities of various urban forms. Data on population distributions and road networks were collected from the best available sources in each city and from remote sensing analysis. Using spatial mapping techniques, we first overlaid road buffers onto population data to estimate the portions of population potentially exposed for four plausible impact zones. Based on a most likely scenario with impacts from highways up to 300meters and major roadways up to 50meters, we identified that the portions of population potentially exposed for the seven cities ranged from 23 to 96%. High-income North American cities had the lowest potential exposure portions, while those in Europe had the highest. Second, we adjusted exposure zone concentration levels based on a literature suggested multiplier for each city using corresponding background concentrations. Though Beijing and Mexico City did not have the highest portion of population exposure, those in their exposure zones had the highest levels of exposure. For all seven cities, the portion of population potentially exposed was positively correlated with roadway density and, to a lesser extent, with population density. These analyses suggest that urban form may influence the portion of population exposed to TRAP and vehicle emissions and other factors may influence the exposure levels. Greater understanding of urban form and other factors influencing potential exposure to TRAP may help inform interventions that protect public health. Copyright © 2014 Elsevier Ltd. All rights reserved.

Volatile Organic Compounds Enhance Allergic Airway Inflammation in an Experimental Mouse Model

PubMed Central

Bönisch, Ulrike; Böhme, Alexander; Kohajda, Tibor; Mögel, Iljana; Schütze, Nicole; von Bergen, Martin; Simon, Jan C.; Lehmann, Irina; Polte, Tobias

2012-01-01

Background Epidemiological studies suggest an association between exposure to volatile organic compounds (VOCs) and adverse allergic and respiratory symptoms. However, whether VOCs exhibit a causal role as adjuvants in asthma development remains unclear. Methods To investigate the effect of VOC exposure on the development of allergic airway inflammation Balb/c mice were exposed to VOCs emitted by new polyvinylchloride (PVC) flooring, sensitized with ovalbumin (OVA) and characterized in acute and chronic murine asthma models. Furthermore, prevalent evaporated VOCs were analyzed and mice were exposed to selected single VOCs. Results Exposure of mice to PVC flooring increased eosinophilic lung inflammation and OVA-specific IgE serum levels compared to un-exposed control mice. The increased inflammation was associated with elevated levels of Th2-cytokines. Long-term exposure to PVC flooring exacerbated chronic airway inflammation. VOCs with the highest concentrations emitted by new PVC flooring were N-methyl-2-pyrrolidone (NMP) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB). Exposure to NMP or TXIB also increased the allergic immune response in OVA-sensitized mice. In vitro or in vivo exposure to NMP or TXIB reduced IL-12 production in maturing dendritic cells (DCs) and enhanced airway inflammation after adoptive DC transfer into Balb/c mice. At higher concentrations both VOCs induced oxidative stress demonstrated by increased isoprostane and glutathione-S-transferase-pi1 protein levels in the lung of non-sensitized mice. Treatment of PVC flooring-exposed mice with N-acetylcysteine prevented the VOC-induced increase of airway inflammation. Conclusions Our results demonstrate that exposure to VOCs may increase the allergic immune response by interfering with DC function and by inducing oxidative stress and has therefore to be considerate as risk factor for the development of allergic diseases. PMID:22802943

Urinary naphthol metabolites and chromosomal aberrations in 5 yr old children

PubMed Central

Orjuela, Manuela A.; Liu, XinHua; Miller, Rachel L.; Warburton, Dorothy; Tang, DeLiang; Jobanputra, Vaidehi; Hoepner, Lori; Suen, Ida Hui; Diaz-Carreno, Silvia; Li, Zheng; Sjodin, Andreas; Perera, Frederica P.

2012-01-01

Background Exposure to naphthalene, an IARC-classified possible carcinogen and polycyclic aromatic hydrocarbon (PAH), is widespread, though resulting health effects are poorly understood. Metabolites of naphthalene, 1- and 2-naphthol, are measurable in urine and are biomarkers of personal exposure. Chromosomal aberrations (CAs), including translocations, are established markers of cancer risk and a bio-dosimeter of clastogenic exposures. Although prenatal (maternal) PAH exposure predicts CAs in cord blood, few studies have examined CAs in school-age children and none has examined their association with metabolites of specific PAHs. Methods Using Whole Chromosome Paint Fluorescent in Situ Hybridization, we documented CAs including translocations, in 113 five year old urban minority children and examined their association with concurrent concentrations of PAH metabolites measured in urine. Results We report that in lymphocytes, the occurrence and frequency of CAs including translocations are associated with levels of urinary 1- and 2-naphthol. When doubling the levels of urinary naphthols, gender-adjusted Odds Ratio (OR) for CAs are 1.63 (95%CI: 1.21, 2.19) and 1.44 (95%CI: 1.02, 2.04) for 1-and 2-naphthol respectively; and for translocations: OR=1.55 (95%CI: 1.11-2.17) and 1.92 (95%CI: 1.20-3.08) for 1- and 2-naphthol respectively. Conclusion Our results demonstrate that markers of exposure to naphthalene in children are associated with translocations in a dose related manner, and that naphthalene may be a clastogen. Impact Indoor exposure to elevated levels of naphthalene is prevalent in large regions of the world. This study is the first to present an association between a marker of naphthalene exposure and a pre-carcinogenic effect in humans. PMID:22573794

Occurrence of 210Po and Biological Effects of Low-Level Exposure: The Need for Research

PubMed Central

Wiemels, Joseph L.

2012-01-01

Background: Polonium-210 (210Po) concentrations that exceed 1 Bq/L in drinking-water supplies have been reported from four widely separated U.S. states where exposure to it went unnoticed for decades. The radionuclide grandparents of 210Po are common in sediments, and segments of the public may be chronically exposed to low levels of 210Po in drinking water or in food products from animals raised in contaminated areas. Objectives: We summarized information on the environmental behavior, biokinetics, and toxicology of 210Po and identified the need for future research. Methods: Potential linkages between environmental exposure to 210Po and human health effects were identified in a literature review. Discussion: 210Po accumulates in the ovaries where it kills primary oocytes at low doses. Because of its radiosensitivity and tendency to concentrate 210Po, the ovary may be the critical organ in determining the lowest injurious dose for 210Po. 210Po also accumulates in the yolk sac of the embryo and in the fetal and placental tissues. Low-level exposure to 210Po may have subtle, long-term biological effects because of its tropism towards reproductive and embryonic and fetal tissues where exposure to a single alpha particle may kill or damage critical cells. 210Po is present in cigarettes and maternal smoking has several effects that appear consistent with the toxicology of 210Po. Conclusions: Much of the important biological and toxicological research on 210Po is more than four decades old. New research is needed to evaluate environmental exposure to 210Po and the biological effects of low-dose exposure to it so that public health officials can develop appropriate mitigation measures where necessary. PMID:22538346

Occupational Exposure to Ultrafine Particles among Airport Employees - Combining Personal Monitoring and Global Positioning System

PubMed Central

Møller, Karina Lauenborg; Thygesen, Lau Caspar; Schipperijn, Jasper; Loft, Steffen; Bonde, Jens Peter; Mikkelsen, Sigurd; Brauer, Charlotte

2014-01-01

Background Exposure to ultrafine particles (UFP) has been linked to cardiovascular and lung diseases. Combustion of jet fuel and diesel powered handling equipment emit UFP resulting in potentially high exposure levels among employees working at airports. High levels of UFP have been reported at several airports, especially on the apron, but knowledge on individual exposure profiles among different occupational groups working at an airport is lacking. Purpose The aim of this study was to compare personal exposure to UFP among five different occupational groups working at Copenhagen Airport (CPH). Method 30 employees from five different occupational groups (baggage handlers, catering drivers, cleaning staff and airside and landside security) at CPH were instructed to wear a personal monitor of particle number concentration in real time and a GPS device. The measurements were carried out on 8 days distributed over two weeks in October 2012. The overall differences between the groups were assessed using linear mixed model. Results Data showed significant differences in exposure levels among the groups when adjusted for variation within individuals and for effect of time and date (p<0.01). Baggage handlers were exposed to 7 times higher average concentrations (geometric mean, GM: 37×103 UFP/cm3, 95% CI: 25–55×103 UFP/cm3) than employees mainly working indoors (GM: 5×103 UFP/cm3, 95% CI: 2–11×103 UFP/cm3). Furthermore, catering drivers, cleaning staff and airside security were exposed to intermediate concentrations (GM: 12 to 20×103 UFP/cm3). Conclusion The study demonstrates a strong gradient of exposure to UFP in ambient air across occupational groups of airport employees. PMID:25203510

Associations of Prenatal Mercury Exposure From Maternal Fish Consumption and Polyunsaturated Fatty Acids With Child Neurodevelopment: A Prospective Cohort Study in Italy

PubMed Central

Valent, Francesca; Mariuz, Marika; Bin, Maura; Little, D’Anna; Mazej, Darja; Tognin, Veronica; Tratnik, Janja; McAfee, Alison J; Mulhern, Maria S; Parpinel, Maria; Carrozzi, Marco; Horvat, Milena; Tamburlini, Giorgio; Barbone, Fabio

2013-01-01

Background Mercury is a neurotoxin, and limited prenatal exposure to it can affect long-term child neurodevelopment. However, results of epidemiologic studies of such exposure have been inconsistent. We examined the association of prenatal mercury exposure from maternal fish consumption with child neurodevelopment in northern Italy. Methods A population-based cohort of 606 children and their mothers was studied from pregnancy to age 18 months. Mercury levels were measured in maternal hair and blood during pregnancy and in umbilical cord blood and breast milk. Levels of polyunsaturated fatty acids (PUFAs) were measured in maternal serum. Maternal and child intakes of fish were assessed by using a food frequency questionnaire. The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) was used to evaluate child neurodevelopment. Multivariate linear regression was used to examine the association of mercury exposure with BSID-III scores, after controlling for maternal fish intake, PUFAs during pregnancy, and several other confounders. Results Mean weekly fish intake during pregnancy was less than 2 servings. Mercury concentrations in biological samples were low (mean, 1061 ng/g in hair) and moderately correlated with fish intake, particularly of carnivorous species. Maternal ω-3 PUFA concentrations were poorly correlated with fish intake. Maternal intelligence quotient (IQ) and child intake of fish were significantly associated with neurodevelopment scores. In multivariate models, the level of Hg exposure was not associated with neurodevelopmental performance at 18 months. Conclusions In this Italian population, neurodevelopment at 18 months was associated with child intake of fresh fish and maternal IQ rather than with mercury exposure. The expected beneficial effect of maternal fish intake (from maternal ω-3 PUFAs) was not found. PMID:23933621

Effects of low-level exposure to sarin and cyclosarin during the 1991 Gulf War on brain function and brain structure in US veterans

PubMed Central

Chao, Linda L.; Rothlind, Johannes C.; Cardenas, Valerie A.; Meyerhoff, Dieter J.; Weiner, Michael W.

2010-01-01

Background Potentially more than 100,000 US troops may have been exposed to the organophosphate chemical warfare agents sarin (GB) and cyclosarin (GF) when a munitions dump at Khamisiyah, Iraq was destroyed during the Gulf War (GW) in 1991. Although little is known about the long-term neurobehavioral or neurophysiological effects of low-dose exposure to GB/GF in humans, recent studies of GW veterans from the Devens Cohort suggest decrements in certain cognitive domains and atrophy in brain white matter occur individuals with higher estimated levels of presumed GB/GF exposure. The goal of the current study is to determine the generalizability of these findings in another cohort of GW veterans with suspected GB/GF exposure. Methods Neurobehavioral and imaging data collected in a study on Gulf War Illness between 2002–2007 were used in this study. We focused on the data of 40 GW-deployed veterans categorized as having been exposed to GB/GF at Khamisiyah, Iraq and 40 matched controls. Magnetic resonance images (MRI) of the brain were analyzed using automated and semi-automated image processing techniques that produced volumetric measurements of gray matter (GM), white matter (WM), cerebrospinal fluid (CSF) and hippocampus. Results GW veterans with suspected GB/GF exposure had reduced total GM and hippocampal volumes compared to their unexposed peers (p≤0.01). Although there were no group differences in measures of cognitive function or total WM volume, there were significant, positive correlations between total WM volume and measures of executive function and visuospatial abilities in veterans with suspected GB/GF exposure. Conclusions These findings suggest that low-level exposure to GB/GF can have deleterious effects on brain structure and brain function more than decade later. PMID:20580739

Cases series of malignant lymphohematopoietic disorder in korean semiconductor industry.

PubMed

Kim, Eun-A; Lee, Hye-Eun; Ryu, Hyung-Woo; Park, Seung-Hyun; Kang, Seong-Kyu

2011-06-01

Seven cases of malignant lymphohematopoietic (LHP) disorder were claimed to have developed from occupational exposure at two plants of a semiconductor company from 2007 to 2010. This study evaluated the possibility of exposure to carcinogenic agents for the cases. Clinical courses were reviewed with assessing possible exposure to carcinogenic agents related to LHP cancers. Chemicals used at six major semiconductor companies in Korea were reviewed. Airborne monitoring for chemicals, including benzene, was conducted and the ionizing radiation dose was measured from 2008 to 2010. The latency of seven cases (five leukemiae, a Non-Hodgkin's lymphoma, and an aplastic anemia) ranged from 16 months to 15 years and 5 months. Most chemical measurements were at levels of less than 10% of the Korean Occupational Exposure Limit value. No carcinogens related to LHP cancers were used or detected. Complete-shielded radiation-generating devices were used, but the ionizing radiation doses were 0.20-0.22 uSv/hr (background level: 0.21 µSv/hr). Airborne benzene was detected at 0.31 ppb when the detection limit was lowered as low as possible. Ethylene oxide and formaldehyde were not found in the cases' processes, while these two were determined to be among the 263 chemicals in the list that was used at the six semiconductor companies at levels lower than 0.1%. Exposures occurring before 2002 could not be assessed because of the lack of information. Considering the possibility of exposure to carcinogenic agents, we could not find any convincing evidence for occupational exposure in all investigated cases. However, further study is needed because the semiconductor industry is a newly developing one.

Cases Series of Malignant Lymphohematopoietic Disorder in Korean Semiconductor Industry

PubMed Central

Lee, Hye-Eun; Ryu, Hyung-Woo; Park, Seung-Hyun; Kang, Seong-Kyu

2011-01-01

Objectives Seven cases of malignant lymphohematopoietic (LHP) disorder were claimed to have developed from occupational exposure at two plants of a semiconductor company from 2007 to 2010. This study evaluated the possibility of exposure to carcinogenic agents for the cases. Methods Clinical courses were reviewed with assessing possible exposure to carcinogenic agents related to LHP cancers. Chemicals used at six major semiconductor companies in Korea were reviewed. Airborne monitoring for chemicals, including benzene, was conducted and the ionizing radiation dose was measured from 2008 to 2010. Results The latency of seven cases (five leukemiae, a Non-Hodgkin's lymphoma, and an aplastic anemia) ranged from 16 months to 15 years and 5 months. Most chemical measurements were at levels of less than 10% of the Korean Occupational Exposure Limit value. No carcinogens related to LHP cancers were used or detected. Complete-shielded radiation-generating devices were used, but the ionizing radiation doses were 0.20-0.22 uSv/hr (background level: 0.21 µSv/hr). Airborne benzene was detected at 0.31 ppb when the detection limit was lowered as low as possible. Ethylene oxide and formaldehyde were not found in the cases' processes, while these two were determined to be among the 263 chemicals in the list that was used at the six semiconductor companies at levels lower than 0.1%. Exposures occurring before 2002 could not be assessed because of the lack of information. Conclusion Considering the possibility of exposure to carcinogenic agents, we could not find any convincing evidence for occupational exposure in all investigated cases. However, further study is needed because the semiconductor industry is a newly developing one. PMID:22953195

Antibody Levels to Persistent Pathogens and Incident Stroke in Mexican Americans

PubMed Central

Sealy-Jefferson, Shawnita; Gillespie, Brenda W.; Aiello, Allison E.; Haan, Mary N.; Morgenstern, Lewis B.; Lisabeth, Lynda D.

2013-01-01

Background Persistent pathogens have been proposed as risk factors for stroke; however, the evidence remains inconclusive. Mexican Americans have an increased risk of stroke especially at younger ages, as well as a higher prevalence of infections caused by several persistent pathogens. Methodology/Principal Findings Using data from the Sacramento Area Latino Study on Aging (n = 1621), the authors used discrete-time regression to examine associations between stroke risk and (1) immunoglobulin G antibody levels to Helicobacter pylori (H. pylori), Cytomegalovirus, Varicella Zoster Virus, Toxoplasma gondii and Herpes simplex virus 1, and (2) concurrent exposure to several pathogens (pathogen burden), defined as: (a) summed sero-positivity, (b) number of pathogens eliciting high antibody levels, and (c) average antibody level. Models were adjusted for socio-demographics and stroke risk factors. Antibody levels to H. pylori predicted incident stroke in fully adjusted models (Odds Ratio: 1.58; 95% Confidence Interval: 1.09, 2.28). No significant associations were found between stroke risk and antibody levels to the other four pathogens. No associations were found for pathogen burden and incident stroke in fully adjusted models. Conclusions/Significance Our results suggest that exposure to H. pylori may be a stroke risk factor in Mexican Americans and may contribute to ethnic differences in stroke risk given the increased prevalence of exposure to H. pylori in this population. Future studies are needed to confirm this association. PMID:23799066

Determination of Selected Chemical Levels in Room Air and on Surfaces after the Use of Cartridge- and Tank-Based E-Vapor Products or Conventional Cigarettes.

PubMed

Liu, Jianmin; Liang, Qiwei; Oldham, Michael J; Rostami, Ali A; Wagner, Karl A; Gillman, I Gene; Patel, Piyush; Savioz, Rebecca; Sarkar, Mohamadi

2017-08-28

There is an ongoing debate regarding the potential of secondhand exposure of non-users to various chemicals from use of e-vapor products (EVPs). Room air levels of 34 chemicals (nicotine, propylene glycol (PG), glycerol, 15 carbonyl chemicals, 12 volatile organic chemicals (VOCs), and four selected trace elements) were measured where EVPs and cigarettes were used by n = 37 healthy adult tobacco users in an exposure chamber. The products used were MarkTen ® 2.5% Classic (Group I), a Prototype GreenSmoke ® 2.4% (Group II), Ego-T ® Tank with subjects' own e-liquids (Group III) and subjects' own conventional cigarettes (Group IV). Products were used under controlled conditions and 4-h ad libitum use. Background (without subjects) and baseline levels (with subjects) were measured. Cumulative 4-h. levels of nicotine, PG and glycerol measured were several-fold below the time-weighted average limits used in workplace exposure evaluation. Most the other chemicals (>75%) were at or below the limit of quantification during EVP use. Significant levels of chemicals (17 out of 34) were observed in Group IV. Overall, our results indicate that under the study conditions with the products tested, cumulative room air levels of the selected chemicals measured over 4-h were relatively small and were several-fold below the current occupational regulatory and consensus limits.

Oral contraceptives cause evolutionarily novel increases in hormone exposure

PubMed Central

Lovett, Jennie L; Chima, Margo A; Wexler, Juliana K; Arslanian, Kendall J; Friedman, Andrea B; Yousif, Chantal B; Strassmann, Beverly I

2017-01-01

Abstract Background and objectives In the evolutionary past, women spent most of their reproductive lives either pregnant or in lactational amenorrhea, and rarely menstruated. The current pattern of frequent menses, and the associated increase in endogenous hormonal exposure, has been implicated in the current breast cancer epidemic. It is not known, however, whether oral contraceptives further increase, or actually decrease, hormonal exposure over one menstrual cycle. Here, we examined variation in hormonal exposure across seven oral contraceptive (OC) formulations, and produced the first quantitative comparison of exogenous versus endogenous hormone exposure. Methodology Data from 12 studies of serum estradiol (E2) and progesterone (P4) were aggregated to create a composite graph of endogenous hormone levels over one menstrual cycle in European or American women (age 19–40 years). Pharmacokinetic package insert data, also from Western women, were used to calculate exposures for hormones in seven different OC formulations. Endogenous and exogenous hormone levels were compared after adjusting for the relative binding affinity (RBA) of progestin to the progesterone receptor and ethinyl estradiol (EE) to the estrogen receptor. Results After adjusting for RBA, median ethinyl estradiol exposure across 28 days in the OCs was 11.4 nmol/l, similar to median E2 exposure. One formulation, however, was 40% higher in ethinyl estradiol exposure relative to median endogenous estradiol. Median exposure from progestins in OCs (1496 nmol/l) was 4-fold higher than the median endogenous exposure from P4 (364 nmol/l). Exposure from OC progestins ranged from one sixtieth to 8-fold median endogenous P4 over 28 days. Conclusions and implications Given that breast cancer risk increases with hormonal exposure, our finding that four widely prescribed formulations more than quadruple progestin exposure relative to endogenous progesterone exposure is cause for concern. As not all formulations produce the same exposures, these findings are pertinent to contraceptive choice. We also identify critical gaps in the provision of relevant data on pharmacokinetics and carcinogenicity by drug manufacturers. PMID:28685096

Background-free search for neutrinoless double-β decay of 76Ge with GERDA.

PubMed

2017-04-05

Many extensions of the Standard Model of particle physics explain the dominance of matter over antimatter in our Universe by neutrinos being their own antiparticles. This would imply the existence of neutrinoless double-β decay, which is an extremely rare lepton-number-violating radioactive decay process whose detection requires the utmost background suppression. Among the programmes that aim to detect this decay, the GERDA Collaboration is searching for neutrinoless double-β decay of 76 Ge by operating bare detectors, made of germanium with an enriched 76 Ge fraction, in liquid argon. After having completed Phase I of data taking, we have recently launched Phase II. Here we report that in GERDA Phase II we have achieved a background level of approximately 10 -3 counts keV -1 kg -1 yr -1 . This implies that the experiment is background-free, even when increasing the exposure up to design level. This is achieved by use of an active veto system, superior germanium detector energy resolution and improved background recognition of our new detectors. No signal of neutrinoless double-β decay was found when Phase I and Phase II data were combined, and we deduce a lower-limit half-life of 5.3 × 10 25 years at the 90 per cent confidence level. Our half-life sensitivity of 4.0 × 10 25 years is competitive with the best experiments that use a substantially larger isotope mass. The potential of an essentially background-free search for neutrinoless double-β decay will facilitate a larger germanium experiment with sensitivity levels that will bring us closer to clarifying whether neutrinos are their own antiparticles.

Background-free search for neutrinoless double-β decay of 76Ge with GERDA

NASA Astrophysics Data System (ADS)

Agostini, M.; Allardt, M.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Borowicz, D.; Brudanin, V.; Brugnera, R.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; D'Andrea, V.; Demidova, E. V.; di Marco, N.; di Vacri, A.; Domula, A.; Doroshkevich, E.; Egorov, V.; Falkenstein, R.; Fedorova, O.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gooch, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hakenmüller, J.; Hegai, A.; Heisel, M.; Hemmer, S.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Janicskó Csáthy, J.; Jochum, J.; Junker, M.; Kazalov, V.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Kish, A.; Klimenko, A.; Kneißl, R.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Liao, H. Y.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Medinaceli, E.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Nemchenok, I.; Palioselitis, D.; Panas, K.; Pandola, L.; Pelczar, K.; Pullia, A.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salamida, F.; Salathe, M.; Schmitt, C.; Schneider, B.; Schönert, S.; Schreiner, J.; Schulz, O.; Schütz, A.-K.; Schwingenheuer, B.; Selivanenko, O.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Vanhoefer, L.; Vasenko, A. A.; Veresnikova, A.; von Sturm, K.; Wagner, V.; Walter, M.; Wegmann, A.; Wester, T.; Wiesinger, C.; Wojcik, M.; Yanovich, E.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.; GERDA Collaboration

2017-04-01

Many extensions of the Standard Model of particle physics explain the dominance of matter over antimatter in our Universe by neutrinos being their own antiparticles. This would imply the existence of neutrinoless double-β decay, which is an extremely rare lepton-number-violating radioactive decay process whose detection requires the utmost background suppression. Among the programmes that aim to detect this decay, the GERDA Collaboration is searching for neutrinoless double-β decay of 76Ge by operating bare detectors, made of germanium with an enriched 76Ge fraction, in liquid argon. After having completed Phase I of data taking, we have recently launched Phase II. Here we report that in GERDA Phase II we have achieved a background level of approximately 10-3 counts keV-1 kg-1 yr-1. This implies that the experiment is background-free, even when increasing the exposure up to design level. This is achieved by use of an active veto system, superior germanium detector energy resolution and improved background recognition of our new detectors. No signal of neutrinoless double-β decay was found when Phase I and Phase II data were combined, and we deduce a lower-limit half-life of 5.3 × 1025 years at the 90 per cent confidence level. Our half-life sensitivity of 4.0 × 1025 years is competitive with the best experiments that use a substantially larger isotope mass. The potential of an essentially background-free search for neutrinoless double-β decay will facilitate a larger germanium experiment with sensitivity levels that will bring us closer to clarifying whether neutrinos are their own antiparticles.

Burden of Household Environmental Tobacco Smoke on Medical Expenditure for Japanese Women: A Population-Based Cohort Study

PubMed Central

Morishima, Toshitaka; Imanaka, Yuichi; Otsubo, Tetsuya; Hayashida, Kenshi; Watanabe, Takashi; Tsuji, Ichiro

2013-01-01

Background The economic consequences of environmental tobacco smoke (ETS) have been simulated using models. We examined the individual-level association between ETS exposure and medical costs among Japanese nonsmoking women. Methods This population-based cohort study enrolled women aged 40 to 79 years living in a rural community. ETS exposure in homes at baseline was assessed with a self-administered questionnaire. We then collected health insurance claims data on direct medical expenditures from 1995 through 2007. Using generalized linear models with interaction between ETS exposure level and age stratum, average total monthly expenditure (inpatient plus outpatient care) per capita for nonsmoking women highly exposed and moderately exposed to ETS were compared with expenditures for unexposed women. We performed separate analyses for survivors and nonsurvivors. Results We analyzed data from 4870 women. After adjustment for potential confounding factors, survivors aged 70 to 79 who were highly exposed to ETS incurred higher expenditures than those who were not exposed. We found no significant difference in expenditures between moderately exposed and unexposed women. Total expenditures were not significantly associated with ETS exposure among survivors aged 40 to 69 or nonsurvivors of any age stratum. Conclusions We calculated individual-level excess medical expenditures attributable to household exposure to ETS among surviving older women. The findings provide direct evidence of the economic burden of ETS, which is helpful for policymakers who seek to achieve the economically attractive goal of eliminating ETS. PMID:23183111

Issue Paper on Metal Exposure Assessment

EPA Pesticide Factsheets

This paper explores the best approaches for characterizing exposure pathways and routes, estimating the most relevant exposure concentrations, linking exposure to dose, and coping with natural or background concentrations.

Exposure source prevalence is associated with gender in hepatitis C virus patients from Rio de Janeiro, Brazil

PubMed Central

Olmedo, Daniele Blasquez; Precioso, Patrícia Marraccini; Lugdero-Correia, António; da Silva, Guida; dos Santos, Angela Maria Guimarães; Pôrto, Luís Cristóvão

2017-01-01

BACKGROUND Hepatitis C virus (HCV) infection is a worldwide public health problem. A characterisation of the differences in exposure sources among genders will enable improvements in surveillance actions. METHODS Exposure data were obtained for 1180 confirmed HCV cases Brazil’s mandatory reporting to epidemiological surveillance, which was directed by a reference laboratory in Rio de Janeiro, Brazil. The Chi-square test (χ2) was used to assess the associations between exposure sources and gender. The prevalence ratio (PR) was calculated for exposures that showed an association. RESULTS The results showed 57.7% cases were female, and associations with snorting drugs, sexual activity, surgery, aesthetic procedures, blood transfusions, and educational level were observed (p < 0.001). Men showed 2.53 (1.33-3.57), 4.83 (3.54-6.59), and 2.18 (1.33-3.57) times more exposure to sniffing drugs, risky sex and higher levels of education, respectively, than women. Women demonstrated 4.46 (3.21-6.21), 1.94 (1.43-2.63), and 3.10 (2.09-4.61) times more exposure to surgery, aesthetic procedures, and blood transfusions, respectively, than men. CONCLUSION Our results showed differences in risk behaviours associated with gender among HCV carriers. These data are likely to significantly influence clinical practice regarding the adoption of specific approaches for counselling and control policies to prevent the emergence of new cases and break the chain of transmission of the virus. PMID:28902289

Potential for Increased Human Foodborne Exposure to PCDD/F When Recycling Sewage Sludge on Agricultural Land

PubMed Central

Rideout, Karen; Teschke, Kay

2004-01-01

Sewage sludge from municipal wastewater treatment is used in agriculture as a nutrient source and to aid in moisture retention. To examine the potential impact of sludge-amended soil on exposures to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from plant and animal foods, we conducted a review of published empirical data from international sources. Levels of PCDD/F in municipal sewage sludge ranged from 0.0005 to 8,300 pg toxic equivalents (TEQ)/g. Background levels in soil ranged from 0.003 to 186 pg TEQ/g. In sludge-amended soils, levels of PCDD/F ranged from 1.4 to 15 pg TEQ/g. Studies that measured levels before and after sludge treatment showed an increase in soil concentration after treatment. Relationships between PCDD/F levels in soil and resulting concentrations in plants were very weakly positive for unpeeled root crops, leafy vegetables, tree fruits, hay, and herbs. Somewhat stronger relationships were observed for plants of the cucumber family. In all cases, large increases in soil concentration were required to achieve a measurable increase in plant contamination. A considerably stronger positive relationship was observed between PCDD/F in feed and resulting levels in cattle tissue, suggesting bioaccumulation. Although PCDD/Fs are excreted in milk, no association was found between feed contamination and levels of PCDD/Fs measured in milk. There is a paucity of realistic data describing the potential for entry of PCDD/Fs into the food supply via sewage sludge. Currently available data suggest that sewage sludge application to land used for most crops would not increase human exposure. However, the use of sludge on land used to graze animals appears likely to result in increased human exposure to PCDD/F. PMID:15198915

Socioeconomic status and exposure to outdoor NO2 and benzene in the Asturias INMA birth cohort, Spain

PubMed Central

Fernández-Somoano, Ana; Tardon, Adonina

2014-01-01

Background It is commonly assumed that low socioeconomic levels are associated with greater exposure to pollution, but this is not necessarily valid. Our goal was to examine how individual socioeconomic characteristics are associated with exposure levels in a Spanish region included in the INfancia y Medio Ambiente (INMA) cohort. Methods The study population comprised 430 pregnant women from the Asturias INMA cohort. Air pollution exposure was estimated using land-use regression techniques. Information about the participants’ lifestyle and socioeconomic variables was collected through questionnaires. In multivariate analysis, the levels of NO2 and benzene assigned to each woman were considered as dependent variables. Other variables included in the models were residential zone, age, education, parity, smoking, season, working status during pregnancy and social class. Results The average NO2 level was 23.60 (SD=6.50) μg/m3. For benzene, the mean value was 2.31 (SD=1.32) μg/m3. We found no association of any pollutant with education. We observed an association between social class and benzene levels. Social classes I and II had the highest levels. The analysed socioeconomic and lifestyle variables accounted for little variability in air pollution in the models; this variability was explained mainly by residential zone (adjusted R2: 0.27 for NO2; 0.09 for benzene). Conclusions Education and social class were not clearly associated with pollution. Administrations should monitor the environment of residential areas regardless of the socioeconomic level, and they should increase the distances between housing and polluting sources to prevent settlements at distances that are harmful to health. PMID:23999377

Cadmium-induced ethylene production and responses in Arabidopsis thaliana rely on ACS2 and ACS6 gene expression

PubMed Central

2014-01-01

Background Anthropogenic activities cause metal pollution worldwide. Plants can absorb and accumulate these metals through their root system, inducing stress as a result of excess metal concentrations inside the plant. Ethylene is a regulator of multiple plant processes, and is affected by many biotic and abiotic stresses. Increased ethylene levels have been observed after exposure to excess metals but it remains unclear how the increased ethylene levels are achieved at the molecular level. In this study, the effects of cadmium (Cd) exposure on the production of ethylene and its precursor 1-aminocyclopropane-1-carboxylic acid (ACC), and on the expression of the ACC Synthase (ACS) and ACC Oxidase (ACO) multigene families were investigated in Arabidopsis thaliana. Results Increased ethylene release after Cd exposure was directly measurable in a system using rockwool-cultivated plants; enhanced levels of the ethylene precursor ACC together with higher mRNA levels of ethylene responsive genes: ACO2, ETR2 and ERF1 also indicated increased ethylene production in hydroponic culture. Regarding underlying mechanisms, it was found that the transcript levels of ACO2 and ACO4, the most abundantly expressed members of the ACO multigene family, were increased upon Cd exposure. ACC synthesis is the rate-limiting step in ethylene biosynthesis, and transcript levels of both ACS2 and ACS6 showed the highest increase and became the most abundant isoforms after Cd exposure, suggesting their importance in the Cd-induced increase of ethylene production. Conclusions Cadmium induced the biosynthesis of ACC and ethylene in Arabidopsis thaliana plants mainly via the increased expression of ACS2 and ACS6. This was confirmed in the acs2-1acs6-1 double knockout mutants, which showed a decreased ethylene production, positively affecting leaf biomass and resulting in a delayed induction of ethylene responsive gene expressions without significant differences in Cd contents between wild-type and mutant plants. PMID:25082369

Association of Prenatal and Early Life Exposure to Tetrachloroethylene (PCE) with Polycystic Ovary Syndrome and Other Reproductive Disorders in the Cape Cod Health Study: A Retrospective Cohort Study

PubMed Central

Mahalingaiah, Shruthi; Winter, Michael R.; Aschengrau, Ann

2016-01-01

Background Tetrachloroethylene (PCE) is an organic lipophilic solvent with possible neuroendocrine toxicity. The objective of this study was to determine the association of prenatal and early childhood exposure to PCE-contaminated drinking water and development of adult-onset Polycystic Ovary Syndrome (PCOS), endometriosis, difficulty conceiving and miscarriage. Methods Five-hundred exposed and 331 unexposed female participants born between 1969 and 1983 completed questionnaires on demographic and lifestyle characteristics, and reproductive disorders. Residential locations from the prenatal period through five years of age were used to estimate early life PCE exposure with water modeling software. Results For any early life exposure to PCE, the adjusted risk ratio for PCOS was 0.9 (95% CI: 0.5–1.6). No statistically significant associations were observed for increasing levels of exposure with PCOS or the other reproductive disorders. Conclusion No meaningful associations were found among adult women with early life exposure to PCE-contaminated drinking water and adult-onset reproductive disorders. PMID:27412368

The effects of magnetic fields exposure on relative permittivity of saline solutions measured by a high resolution SPR system

PubMed Central

Jiang, Li; Zhao, Xinyuan; Fei, Yue; Yu, Dongdong; Qian, Jun; Tong, Jinguang; Chen, Guangdi; He, Sailing

2016-01-01

A measurement system for the relative permittivity of a physiological solution under 50 Hz magnetic fields (MF) is presented. It is based on a phase-sensitive surface plasmon resonance (SPR) system. Relative permittivity was analyzed for different solute concentrations of sodium chloride under various MF exposure parameters. We found that MF exposure at 0.2–4.0 mT step-wise decreased significantly the SPR phase signal of a 0.9% sodium chloride solution while 0.1 mT of MF exposure did not. The decreases in the SPR phase signal depended on the duration of MF exposure, and the signal reached a plateau after 15 min of exposure. Interestingly, the decreased SPR phase signal showed a gradual increase and approached the background level when the exposure was drawn off. In addition, we found that the response of the sodium chloride solution to MF also depended on its concentration. In brief, the relative permittivity of sodium chloride in solutions appears to be practically affected by 50 Hz MF exposure. Our data indicates that the relative permittivity of the saline solution influenced by MF exposure should be considered when investigating the biological effects of MF exposure on organisms in experimental study. PMID:27121618

Effects of Systematic Cue Exposure Through Virtual Reality on Cigarette Craving

PubMed Central

Pericot-Valverde, Irene; Secades-Villa, Roberto; Gutiérrez-Maldonado, José

2014-01-01

Introduction: Cigarette cravings have been associated with less successful attempts to quit smoking and a greater likelihood of relapse after smoking cessation. Background craving refers to a relatively steady and continuous experience of craving, while cue-induced craving refers to phases of intense craving triggered by cues associated with smoking. Cue exposure treatment (CET) involves repeated exposure to stimuli associated with substance use in order to reduce craving responses. However, mixed results have been found regarding the effect of CET on both types of craving. The aim of this study was to assess the effect of systematic virtual reality cue exposure treatment (VR-CET) on background and cue-induced cravings. Methods: Participants were 48 treatment-seeking smokers. The VR-CET consisted of prolonged exposure sessions to several interactive virtual environments. The VR-CET was applied once a week over 5 weeks. An individualized hierarchy of exposure was drawn up for each patient starting from the easiest virtual environment. Background and cue-induced cravings were recorded in each session. Results: Cue-induced craving decreased over each session as a result of prolonged exposure. VR-CET also reduced cue-induced and background cravings across the 5 sessions, showing a cumulative effect across the exposure sessions. Conclusions: Our results evidenced the utility of VR-CET in reducing both types of cigarette craving. A combination of CET through VR with psychological treatments may improve current treatments for smoking cessation. PMID:24962558

Maternal Age at Holocaust Exposure and Maternal PTSD Independently Influence Urinary Cortisol Levels in Adult Offspring

PubMed Central

Bader, Heather N.; Bierer, Linda M.; Lehrner, Amy; Makotkine, Iouri; Daskalakis, Nikolaos P.; Yehuda, Rachel

2014-01-01

Background: Parental traumatization has been associated with increased risk for the expression of psychopathology in offspring, and maternal posttraumatic stress disorder (PTSD) appears to increase the risk for the development of offspring PTSD. In this study, Holocaust-related maternal age of exposure and PTSD were evaluated for their association with offspring ambient cortisol and PTSD-associated symptom expression. Method: Ninety-five Holocaust offspring and Jewish comparison subjects received diagnostic and psychological evaluations, and 24 h urinary cortisol was assayed by RIA. Offspring completed the parental PTSD questionnaire to assess maternal PTSD status. Maternal Holocaust exposure was identified as having occurred in childhood, adolescence, or adulthood and examined in relation to offspring psychobiology. Results: Urinary cortisol levels did not differ for Holocaust offspring and comparison subjects but differed significantly in offspring based on maternal age of exposure and maternal PTSD status. Increased maternal age of exposure and maternal PTSD were each associated with lower urinary cortisol in offspring, but did not exhibit a significant interaction. In addition, offspring PTSD-associated symptom severity increased with maternal age at exposure and PTSD diagnosis. A regression analysis of correlates of offspring cortisol indicated that both maternal age of exposure and maternal PTSD were significant predictors of lower offspring urinary cortisol, whereas childhood adversity and offspring PTSD symptoms were not. Conclusion: Offspring low cortisol and PTSD-associated symptom expression are related to maternal age of exposure, with the greatest effects associated with increased age at exposure. These effects are relatively independent of the negative consequences of being raised by a trauma survivor. These observations highlight the importance of maternal age of exposure in determining a psychobiology in offspring that is consistent with increased risk for stress-related pathology. PMID:25071719

Exposure to particles and nitrogen dioxide among taxi, bus and lorry drivers.

PubMed

Lewné, Marie; Nise, Gun; Lind, Marie-Louise; Gustavsson, Per

2006-03-01

The aims of this study have been to investigate the occurrence of systematic differences in the personal exposure to motor exhaust between different groups of taxi, bus and lorry drivers, and to study if these are influenced by the choice of exposure indicator. We used one indicator of the gaseous phase, nitrogen dioxide (NO(2)), and one of the particle phase (measured by DataRAM), of the exhausts. A total of 121 drivers were included in the study: 39 taxi drivers, 42 bus drivers and 40 lorry drivers. Personal measurements were performed during one working day. Nitrogen dioxide was measured with passive diffusive samplers and particles with Data-RAM, a logging instrument using nephelometric monitoring. The instrument measures particles between 0.1 and 10 microm in size. The average exposure to NO(2) for lorry drivers was 68 microg/m(3); for bus drivers 60 microg/m(3) and for taxi drivers 48 microg/m(3). For particles the exposure was 57 microg/m(3) for lorry drivers, 44 microg/m(3) for bus drivers and 26 microg/m(3) for taxi drivers. The result remained unchanged when exposures were adjusted for variation in urban background levels of NO(2) and particulate matter with an aerodynamic diameter <10 microm (PM(10)). Lorry drivers experienced the highest exposure and taxi drivers the lowest with bus drivers in an intermediate position, regardless of whether NO(2) or particles were used as exposure indicator. The levels of both NO(2) and particles were higher for bus drivers in the city than for them driving in the suburbs. Using diesel or petrol as a fuel for taxis had no influence on the exposure for the drivers, indicating that the taxi drivers' exposure mainly depends on exhaust from surrounding traffic.

Exposure to Secondhand Smoke and Associated Factors among Non-Smoking Pregnant Women with Smoking Husbands in Sichuan Province, China

PubMed Central

Yang, Lian; Tong, Elisa K.; Mao, Zhengzhong; Hu, Teh-wei

2013-01-01

Background Secondhand smoke (SHS) exposure harms pregnant women and the fetus. China has the world’s largest number of smokers and a high male smoking prevalence rate. Objective To compare exposure to SHS among rural and urban Chinese non-smoking pregnant women with smoking husbands, and analyze factors associated with the level of SHS exposure and hair nicotine concentration Setting Sichuan province, China. Population In all 1181 non-smoking pregnant women with smoking husbands recruited from eight district/county Women and Children’s hospitals. Methods The women completed a questionnaire in April and May 2008. Based on systematic sampling, 186 pregnant women were selected for sampling the nicotine concentration in their hair. Ordinal logistic regression analysis was conducted to examine correlates with self-reported SHS exposure (total and at home); linear regression was conducted for the sub-sample of hair nicotine concentrations. Main outcome measures Secondhand smoking exposure rates, hair nicotine levels. Results About 75.1% of the non-smoking pregnant women with smoking husbands reported regular SHS exposure. The major source of exposure was through their husband. In the multivariate analysis, the risk of greater SHS exposure (total and at home) and hair nicotine concentration was increased for women who were rural, had a husband with greater cigarette consumption, less knowledge about SHS, less negative attitudes about SHS, and no smoke-free home rules. Conclusions The high prevalence rate of SHS exposure suggests that it is important for non-smoking pregnant women, especially rural women, to establish smoke-free home rules and increase knowledge and negative attitudes towards SHS. PMID:20367430

Exposure estimates to disinfection by-products of chlorinated drinking water.

PubMed Central

Weisel, C P; Kim, H; Haltmeier, P; Klotz, J B

1999-01-01

Exposure to disinfection by-products (DBPs) of drinking water is multiroute and occurs in households serviced by municipal water treatment facilities that disinfect the water as a necessary step to halt the spread of waterborne infectious diseases. Biomarkers of the two most abundant groups of DBPs of chlorination, exhaled breath levels of trihalomethanes (THMs) and urinary levels of two haloacetic acids, were compared to exposure estimates calculated from in-home tap water concentrations and responses to a questionnaire related to water usage. Background THM breath concentrations were uniformly low. Strong relationships were identified between the THM breath concentrations collected after a shower and both the THM water concentration and the THM exposure from a shower, after adjusting for the postshower delay time in collecting the breath sample. Urinary haloacetic acid excretion rates were not correlated to water concentrations. Urinary trichloroacetic acid excretion rates were correlated with ingestion exposure, and that correlation was stronger in a subset of individuals who consumed beverages primarily within their home where the concentration measurements were made. No correlation was observed between an average 48-hr exposure estimate and the urinary dichloroacetic acid excretion rate, presumably because of its short biological half-life. Valid biomarkers were identified for DBP exposures, but the time between the exposure and sample collection should be considered to account for different metabolic rates among the DBPs. Further, using water concentration as an exposure estimate can introduce misclassification of exposure for DBPs whose primary route is ingestion due to the great variability in the amount of water ingested across a population. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:9924004

Monitoring Indoor Exposure to Organophosphate Flame Retardants: Hand Wipes and House Dust

PubMed Central

Hoffman, Kate; Garantziotis, Stavros; Birnbaum, Linda S.

2014-01-01

Background: Organophosphate flame retardants (PFRs) are becoming popular replacements for the phased-out polybrominated diphenyl ether (PBDE) mixtures, and they are now commonly detected in indoor environments. However, little is known about human exposure to PFRs because they cannot be easily measured in blood or serum. Objectives: To investigate relationships between the home environment and internal exposure, we assessed associations between two PFRs, tris(1,3-dichloropropyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP), in paired hand wipe and dust samples and concentrations of their metabolites in urine samples (n = 53). We also assessed short-term variation in urinary metabolite concentrations (n = 11 participants; n = 49 samples). Methods: Adult volunteers in North Carolina, USA, completed questionnaires and provided urine, hand wipe, and household dust samples. PFRs and PBDEs were measured in hand wipes and dust, and bis(1,3-dichloropropyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), metabolites of TDCIPP and TPHP, were measured in urine. Results: TDCIPP and TPHP were detected frequently in hand wipes and dust (> 86.8%), with geometric mean concentrations exceeding those of PBDEs. Unlike PBDEs, dust TDCIPP and TPHP levels were not associated with hand wipes. However, hand wipe levels were associated with urinary metabolites. Participants with the highest hand wipe TPHP mass, for instance, had DPHP levels 2.42 times those of participants with the lowest levels (95% CI: 1.23, 4.77). Women had higher levels of DPHP, but not BDCIPP. BDCIPP and DPHP concentrations were moderately to strongly reliable over 5 consecutive days (intraclass correlation coefficients of 0.81 and 0.51, respectively). Conclusions: PFR exposures are widespread, and hand-to-mouth contact or dermal absorption may be important pathways of exposure. Citation: Hoffman K, Garantziotis S, Birnbaum LS, Stapleton HM. 2015. Monitoring indoor exposure to organophosphate flame retardants: hand wipes and house dust. Environ Health Perspect 123:160–165; http://dx.doi.org/10.1289/ehp.1408669 PMID:25343780

Health Risks Associated with Oil Pollution in the Niger Delta, Nigeria

PubMed Central

Nriagu, Jerome; Udofia, Emilia A.; Ekong, Ibanga; Ebuk, Godwin

2016-01-01

Background: Although there is considerable public concern about the environmental impacts of oil pollution in the Niger Delta of Nigeria, actual evidence on the pathological and psychological effects in the health of local communities is minimally known. We sought to associate the perspective measures of exposure to oil pollution with health outcomes (inventory of health symptoms and functional capacity limitations) and determine how emotional reactions to environmental risks moderate these health outcomes. Method: The study was conducted with 600 participants selected from five local government areas in Akwa Ibom State where oil pollution is rampant. A structured questionnaire was used to collect the data on the respondents’ exposure to oil pollution, self-rated health and disease symptoms, perception of risk of exposure and emotional reactions to local oil pollution. Results: Most of the participants lived in areas with visible oil pollution and/or near gas flaring facilities and regularly suffered direct exposure to oil in their environment. High level of emotional distress was a part of everyone's life for the study population. Risk perception in the study area was mediated, to a large extent, by dreaded hazards (catastrophic fears of pipeline explosions and oil spill fire), visual cues (gas flares and smoke stacks) and chemosensory cues (off-flavor in drinking water). The exposure metrics were found to be significant predictors of the health effects and influencing factors (emotional reactions). Multi-levels models suggest that at the individual level, the demographic variables and direct contact with oil pollution were important mediators of functional capacity limitation. At the community level, emotional distress from fear of the sources of exposure was an important mediator of the health symptoms. Conclusions: This study documents high levels of disease symptoms and environmental distress (worry, annoyance and intolerance) associated with oil pollution in the Niger Delta areas of Nigeria. It highlights the need for some intervention to ameliorate the psychological distress associated with living under such environmental adversity. PMID:27007391

Prenatal Exposure to Organophosphate Pesticides and Neurobehavioral Development of Neonates: A Birth Cohort Study in Shenyang, China

PubMed Central

Zhang, Ying; Han, Song; Liang, Duohong; Shi, Xinzhu; Wang, Fengzhi; Liu, Wei; Zhang, Li; Chen, Lixin; Gu, Yingzi; Tian, Ying

2014-01-01

Background A large amount of organophosphate pesticides (OPs) are used in agriculture in China every year, contributing to exposure of OPs through dietary consumption among the general population. However, the level of exposure to OPs in China is still uncertain. Objective To investigate the effect of the exposure to OPs on the neonatal neurodevelopment during pregnancy in Shenyang, China. Methods 249 pregnant women enrolled in the Central Hospital Affiliated to Shenyang Medical College from February 2011 to August 2012. A cohort of the mothers and their neonates participated in the study and information on each subject was obtained by questionnaire. Dialkyl phosphate (DAP) metabolites were detected in the urine of mothers during pregnancy to evaluate the exposure level to OPs. Neonate neurobehavioral developmental levels were assessed according to the standards of the Neonatal Behavioral Neurological Assessment (NBNA). Multiple linear regressions were utilized to analyze the association between pregnancy exposure to OPs and neonatal neurobehavioral development. Results The geometric means (GM) of urinary metabolites for dimethyl phosphate (DMP), dimethyl thiophosphate (DMTP), diethyl phosphate (DEP), and diethyl thiophosphate (DETP) in pregnant women were 18.03, 8.53, 7.14, and 5.64 µg/L, respectively. Results from multiple linear regressions showed that prenatal OP exposure was one of the most important factors affecting NBNA scores. Prenatal total DAP concentrations were inversely associated with scores on the NBNA scales.?Additionally, a 10-fold increase in DAP concentrations was associated with a decrease of 1.78 regarding the Summary NBNA (95% CI, −2.12 to −1.45). And there was an estimated 2.11-point difference in summary NBNA scores between neonates in the highest quintile of prenatal OP exposure and the lowest quintile group. Conclusion The high exposure of pregnant women to OPs in Shenyang, China was the predominant risk factor for neonatal neurobehavioral development. PMID:24551109

From Good Intentions to Proven Interventions: Effectiveness of Actions to Reduce the Health Impacts of Air Pollution

PubMed Central

Giles, Luisa V.; Barn, Prabjit; Künzli, Nino; Romieu, Isabelle; Mittleman, Murray A.; van Eeden, Stephan; Allen, Ryan; Carlsten, Chris; Stieb, Dave; Noonan, Curtis; Smargiassi, Audrey; Kaufman, Joel D.; Hajat, Shakoor; Kosatsky, Tom; Brauer, Michael

2011-01-01

Background Associations between air pollution and a multitude of health effects are now well established. Given ubiquitous exposure to some level of air pollution, the attributable health burden can be high, particularly for susceptible populations. Objectives An international multidisciplinary workshop was convened to discuss evidence of the effectiveness of actions to reduce health impacts of air pollution at both the community and individual level. The overall aim was to summarize current knowledge regarding air pollution exposure and health impacts leading to public health recommendations. Discussion During the workshop, experts reviewed the biological mechanisms of action of air pollution in the initiation and progression of disease, as well as the state of the science regarding community and individual-level interventions. The workshop highlighted strategies to reduce individual baseline risk of conditions associated with increased susceptibility to the effects of air pollution and the need to better understand the role of exposure duration in disease progression, reversal, and adaptation. Conclusion We have identified two promising and largely unexplored strategies to address and mitigate air pollution–related health impacts: reducing individual baseline risk of cardiovascular disease and incorporating air pollution–related health impacts into land-use decisions. PMID:20729178

Atopic asthmatic subjects but not atopic subjects without ...

EPA Pesticide Factsheets

BACKGROUND: Asthma is a known risk factor for acute ozone-associated respiratory disease. Ozone causes an immediate decrease in lung function and increased airway inflammation. The role of atopy and asthma in modulation of ozone-induced inflammation has not been determined. OBJECTIVE: We sought to determine whether atopic status modulates ozone response phenotypes in human subjects. METHODS: Fifty volunteers (25 healthy volunteers, 14 atopic nonasthmatic subjects, and 11 atopic asthmatic subjects not requiring maintenance therapy) underwent a 0.4-ppm ozone exposure protocol. Ozone response was determined based on changes in lung function and induced sputum composition, including airway inflammatory cell concentration, cell-surface markers, and cytokine and hyaluronic acid concentrations. RESULTS: All cohorts experienced similar decreases in lung function after ozone. Atopic and atopic asthmatic subjects had increased sputum neutrophil numbers and IL-8 levels after ozone exposure; values did not significantly change in healthy volunteers. After ozone exposure, atopic asthmatic subjects had significantly increased sputum IL-6 and IL-1beta levels and airway macrophage Toll-like receptor 4, Fc(epsilon)RI, and CD23 expression; values in healthy volunteers and atopic nonasthmatic subjects showed no significant change. Atopic asthmatic subjects had significantly decreased IL-10 levels at baseline compared with healthy volunteers; IL-10 levels did not significa

Ambient Dose Equivalent in S. Paulo and Bauru cities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Umisedo, Nancy K.; Okuno, Emico; Cancio, Francisco S.

2008-08-07

The Laboratory of Dosimetry (Institute of Physics, University of S. Paulo) performs since 1981 the external individual monitoring of workers exposed to X and gamma rays based on thermoluminescent dosimetry (TLD). Personal dose equivalent refers only to the exposure of workers due to the working activities, and the dose due to background radiation, also measured with TLD, must be subtracted to evaluate it. A compilation of ambient dose equivalent was done to evaluate the dose due to the background radiation in the work places, and also to contribute to the knowledge of the level of indoor radiation to which themore » public is exposed.« less

Air Pollution Exposure and Markers of Placental Growth and Function: The Generation R Study

PubMed Central

Pierik, Frank H.; de Kluizenaar, Yvonne; Hofman, Albert; van Ratingen, Sjoerd W.; Zandveld, Peter Y.J.; Russcher, Henk; Lindemans, Jan; Miedema, Henk M.E.; Steegers, Eric A.P.; Jaddoe, Vincent W.V.

2012-01-01

Background: Air pollution exposure during pregnancy might affect placental growth and function, perhaps leading to pregnancy complications. Objective: We prospectively evaluated the associations of maternal air pollution exposure with markers of placental growth and function among 7,801 pregnant women in the Netherlands. Methods: We estimated levels of particulate matter ≤ 10 µm in aerodynamic diameter (PM10) and nitrogen dioxide (NO2) at the home address for different periods during pregnancy using dispersion modeling techniques. Pro- and anti-angiogenic factors [placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1), respectively] were measured in first- and second-trimester maternal blood and in fetal cord blood samples at delivery. Pulsatility index of the uterine and umbilical arteries was measured by Doppler ultrasound in second and third trimester, and notching was assessed in third trimester. Placenta weight and birth weight were obtained from medical records. Results: Higher PM10 and NO2 exposure levels were associated with lower second-trimester maternal sFlt-1 and PlGF levels. PM10 and NO2 exposures averaged over total pregnancy were associated with higher sFlt-1 and lower PlGF levels in fetal cord blood, consistent with an anti-angiogenic state. PM10 and NO2 exposures were not consistently associated with second- or third-trimester placental resistance indices. NO2 exposure was associated with third-trimester notching (odds ratio 1.33; 95% CI: 0.99, 1.78 per 10-µg/m3 increase in the prior 2 months). PM10 and NO2 exposures were associated with lower placenta weight (–11.8 g; 95% CI: –20.9, –2.7, and –10.7 g; 95% CI: –19.0, –2.4, respectively, per 10-µg/m3 increase in the prior 2 months), but not with placenta to birth weight ratio. Conclusions: Our results suggest that maternal air pollution exposure may influence markers of placental growth and function. Future studies are needed to confirm these findings and explore the maternal and fetal consequences. PMID:22922820

Central Stars of Planetary Nebulae in the LMC

NASA Technical Reports Server (NTRS)

Bianchi, Luciana

2004-01-01

In FUSE cycle 2's program B001 we studied Central Stars of Planetary Nebulae (CSPN) in the Large Magellanic Could. All FUSE observations have been successfully completed and have been reduced, analyzed and published. The analysis and the results are summarized below. The FUSE data were reduced using the latest available version of the FUSE calibration pipeline (CALFUSE v2.2.2). The flux of these LMC post-AGB objects is at the threshold of FUSE's sensitivity, and thus special care in the background subtraction was needed during the reduction. Because of their faintness, the targets required many orbit-long exposures, each of which typically had low (target) count-rates. Each calibrated extracted sequence was checked for unacceptable count-rate variations (a sign of detector drift), misplaced extraction windows, and other anomalies. All the good calibrated exposures were combined using FUSE pipeline routines. The default FUSE pipeline attempts to model the background measured off-target and subtracts it from the target spectrum. We found that, for these faint objects, the background appeared to be over-estimated by this method, particularly at shorter wavelengths (i.e., < 1000 A). We therefore tried two other reductions. In the first method, subtraction of the measured background is turned off and and the background is taken to be the model scattered-light scaled by the exposure time. In the second one, the first few steps of the pipeline were run on the individual exposures (correcting for effects unique to each exposure such as Doppler shift, grating motions, etc). Then the photon lists from the individual exposures were combined, and the remaining steps of the pipeline run on the combined file. Thus, more total counts for both the target and background allowed for a better extraction.

Experimental PVC Material Challenge in Subjects with Occupational PVC Exposure

PubMed Central

Tuomainen, Anneli; Stark, Harri; Seuri, Markku; Hirvonen, Maija-Riitta; Linnainmaa, Markku; Sieppi, Anne; Tukiainen, Hannu

2006-01-01

Background Polyvinyl chloride (PVC) materials have been linked to asthma in several epidemiologic studies, but the possible causal factors remain unknown. Participants We challenged 10 subjects experimentally to degraded PVC products under controlled conditions. All of the subjects had previously experienced respiratory symptoms suspected to be caused by this kind of exposure in their work place. Five subjects had doctor-diagnosed asthma. Methods The subjects were exposed to degraded PVC material in an exposure chamber; a challenge with ceramic tile was used as the control test. We followed exhaled nitric oxide, nasal NO, lung functions, cytokines [tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4), IL-6, and IL-12] and NO in nasal lavage fluid (NAL) during and after the exposures. We also measured 2-ethylhexanol in exhaled breath samples and NAL. Results On the morning after the PVC exposure, subjects reported respiratory tract symptoms significantly more often than they did after the control test (50% vs. 0%, respectively; p = 0.029; n = 10). We did not detect any changes in lung functions or levels of exhaled NO, nasal NO, or NO in NAL after PVC challenge compared with the control test. Cytokine levels increased after both exposures, with no statistically significant difference between situations. All of the exhaled breath samples collected during the PVC exposure contained 2-ethylhexanol. Conclusions PVC flooring challenge can evoke respiratory tract symptoms in exposed subjects. Our results do not support the hypothesis that PVC materials themselves evoke immediate asthmatic reactions. The chamber test used is well suited to this type of exposure study. PMID:16966097

Differential effect of exposure-based therapy and cognitive therapy on post-traumatic stress disorder symptom clusters: A randomized controlled trial.

PubMed

Horesh, Danny; Qian, Meng; Freedman, Sara; Shalev, Arieh

2017-06-01

A question remains regarding differential effects of exposure-based versus non-exposure-based therapies on specific post-traumatic stress disorder (PTSD) symptom clusters. Traumatized emergency room patients were randomized to receive prolonged exposure (PE) or cognitive therapy (CT) without exposure. PE/CT had no differential effect on individual symptom clusters, and change in total PTSD score remained significant even after controlling for the reductions in all three symptom clusters. In addition, baseline levels of PTSD avoidance/intrusion/hyperarousal did not moderate the effects of PE and CT on total PTSD symptom scores. Taken together, these findings challenge the notion that PE and CT are specifically, and differentially, useful in treating one particular PTSD symptom cluster. Despite their different theoretical backgrounds and techniques, the notion that PE and CT (without exposure) target different PTSD symptoms was not confirmed in this study. Thus, both interventions may in fact be equally effective for treating intrusion, avoidance and hyperarousal symptoms. Baseline levels of avoidance, intrusion and hyperarousal may not be good a priori indicators for PTSD treatment selection. The effect of PE and CT on PTSD as a whole does not seem to depend on a reduction in any specific symptom cluster. These findings indicate that exposure and non-exposure interventions may lead to similar results in terms of reductions in specific PTSD symptoms. It is quite possible that individual PTSD clusters may respond to therapy in an inter-related fashion, with one cluster affecting the other. © 2016 The British Psychological Society.

Effects of Prenatal Exposure to Coal-Burning Pollutants on Children’s Development in China

PubMed Central

Tang, Deliang; Li, Tin-yu; Liu, Jason J.; Zhou, Zhi-jun; Yuan, Tao; Chen, Yu-hui; Rauh, Virginia A.; Xie, Jiang; Perera, Frederica

2008-01-01

Background Environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs), lead, and mercury are released by combustion of coal and other fossil fuels. Objectives In the present study we evaluated the association between prenatal exposure to these pollutants and child development measured by the Gesell Developmental Schedules at 2 years of age. Methods The study was conducted in Tongliang, Chongqing, China, where a seasonally operated coal-fired power plant was the major source of ambient PAHs and also contributed lead and mercury to the air. In a cohort of nonsmoking women and their newborns enrolled between March 2002 and June 2002, we measured levels of PAH–DNA adducts, lead, and mercury in umbilical cord blood. PAH–DNA adducts (specifically benzo[a]pyrene adducts) provided a biologically relevant measure of PAH exposure. We also obtained developmental quotients (DQs) in motor, adaptive, language, and social areas. Results Decrements in one or more DQs were significantly associated with cord blood levels of PAH–DNA adducts and lead, but not mercury. Increased adduct levels were associated with decreased motor area DQ (p = 0.043), language area DQ (p = 0.059), and average DQ (p = 0.047) after adjusting for cord lead level, environmental tobacco smoke, sex, gestational age, and maternal education. In the same model, high cord blood lead level was significantly associated with decreased social area DQ (p = 0.009) and average DQ (p = 0.038). Conclusion The findings indicate that exposure to pollutants from the power plant adversely affected the development of children living in Tongliang; these findings have implications for environmental health policy. PMID:18470301

Epidemiology of recreational exposure to freshwater cyanobacteria – an international prospective cohort study

PubMed Central

Stewart, Ian; Webb, Penelope M; Schluter, Philip J; Fleming, Lora E; Burns, John W; Gantar, Miroslav; Backer, Lorraine C; Shaw, Glen R

2006-01-01

Background Case studies and anecdotal reports have documented a range of acute illnesses associated with exposure to cyanobacteria and their toxins in recreational waters. The epidemiological data to date are limited; we sought to improve on the design of some previously conducted studies in order to facilitate revision and refinement of guidelines for exposure to cyanobacteria in recreational waters. Methods A prospective cohort study was conducted to investigate the incidence of acute symptoms in individuals exposed, through recreational activities, to low (cell surface area <2.4 mm2/mL), medium (2.4–12.0 mm2/mL) and high (>12.0 mm2/mL) levels of cyanobacteria in lakes and rivers in southeast Queensland, the central coast area of New South Wales, and northeast and central Florida. Multivariable logistic regression analyses were employed; models adjusted for region, age, smoking, prior history of asthma, hay fever or skin disease (eczema or dermatitis) and clustering by household. Results Of individuals approached, 3,595 met the eligibility criteria, 3,193 (89%) agreed to participate and 1,331 (37%) completed both the questionnaire and follow-up interview. Respiratory symptoms were 2.1 (95%CI: 1.1–4.0) times more likely to be reported by subjects exposed to high levels of cyanobacteria than by those exposed to low levels. Similarly, when grouping all reported symptoms, individuals exposed to high levels of cyanobacteria were 1.7 (95%CI: 1.0–2.8) times more likely to report symptoms than their low-level cyanobacteria-exposed counterparts. Conclusion A significant increase in reporting of minor self-limiting symptoms, particularly respiratory symptoms, was associated with exposure to higher levels of cyanobacteria of mixed genera. We suggest that exposure to cyanobacteria based on total cell surface area above 12 mm2/mL could result in increased incidence of symptoms. The potential for severe, life-threatening cyanobacteria-related illness is likely to be greater in recreational waters that have significant levels of cyanobacterial toxins, so future epidemiological investigations should be directed towards recreational exposure to cyanotoxins. PMID:16606468

Highway proximity associated with cardiovascular disease risk: the influence of individual-level confounders and exposure misclassification

PubMed Central

2013-01-01

Background Elevated cardiovascular disease risk has been reported with proximity to highways or busy roadways, but proximity measures can be challenging to interpret given potential confounders and exposure error. Methods We conducted a cross sectional analysis of plasma levels of C-Reactive Protein (hsCRP), Interleukin-6 (IL-6), Tumor Necrosis Factor alpha receptor II (TNF-RII) and fibrinogen with distance of residence to a highway in and around Boston, Massachusetts. Distance was assigned using ortho-photo corrected parcel matching, as well as less precise approaches such as simple parcel matching and geocoding addresses to street networks. We used a combined random and convenience sample of 260 adults >40 years old. We screened a large number of individual-level variables including some infrequently collected for assessment of highway proximity, and included a subset in our final regression models. We monitored ultrafine particle (UFP) levels in the study areas to help interpret proximity measures. Results Using the orthophoto corrected geocoding, in a fully adjusted model, hsCRP and IL-6 differed by distance category relative to urban background: 43% (-16%,141%) and 49% (6%,110%) increase for 0-50 m; 7% (-39%,45%) and 41% (6%,86%) for 50-150 m; 54% (-2%,142%) and 18% (-11%,57%) for 150-250 m, and 49% (-4%, 131%) and 42% (6%, 89%) for 250-450 m. There was little evidence for association for TNF-RII or fibrinogen. Ortho-photo corrected geocoding resulted in stronger associations than traditional methods which introduced differential misclassification. Restricted analysis found the effect of proximity on biomarkers was mostly downwind from the highway or upwind where there was considerable local street traffic, consistent with patterns of monitored UFP levels. Conclusion We found associations between highway proximity and both hsCRP and IL-6, with non-monotonic patterns explained partly by individual-level factors and differences between proximity and UFP concentrations. Our analyses emphasize the importance of controlling for the risk of differential exposure misclassification from geocoding error. PMID:24090339

Diesel engine exhaust accelerates plaque formation in a mouse model of Alzheimer's disease.

PubMed

Hullmann, Maja; Albrecht, Catrin; van Berlo, Damiën; Gerlofs-Nijland, Miriam E; Wahle, Tina; Boots, Agnes W; Krutmann, Jean; Cassee, Flemming R; Bayer, Thomas A; Schins, Roel P F

2017-08-30

Increasing evidence from toxicological and epidemiological studies indicates that the central nervous system is an important target for ambient air pollutants. We have investigated whether long-term inhalation exposure to diesel engine exhaust (DEE), a dominant contributor to particulate air pollution in urban environments, can aggravate Alzheimer's Disease (AD)-like effects in female 5X Familial AD (5XFAD) mice and their wild-type female littermates. Following 3 and 13 weeks exposures to diluted DEE (0.95 mg/m 3 , 6 h/day, 5 days/week) or clean air (controls) behaviour tests were performed and amyloid-β (Aβ) plaque formation, pulmonary histopathology and systemic inflammation were evaluated. In a string suspension task, assessing for grip strength and motor coordination, 13 weeks exposed 5XFAD mice performed significantly less than the 5XFAD controls. Spatial working memory deficits, assessed by Y-maze and X-maze tasks, were not observed in association with the DEE exposures. Brains of the 3 weeks DEE-exposed 5XFAD mice showed significantly higher cortical Aβ plaque load and higher whole brain homogenate Aβ42 levels than the clean air-exposed 5XFAD littermate controls. After the 13 weeks exposures, with increasing age and progression of the AD-phenotype of the 5XFAD mice, DEE-related differences in amyloid pathology were no longer present. Immunohistochemical evaluation of lungs of the mice revealed no obvious genetic background-related differences in tissue structure, and the DEE exposure did not cause histopathological changes in the mice of both backgrounds. Luminex analysis of plasma cytokines demonstrated absence of sustained systemic inflammation upon DEE exposure. Inhalation exposure to DEE causes accelerated plaque formation and motor function impairment in 5XFAD transgenic mice. Our study provides further support that the brain is a relevant target for the effects of inhaled DEE and suggests that long-term exposure to this ubiquitous air pollution mixture may promote the development of Alzheimer's disease.

Maternal exposure to air pollution before and during pregnancy related to changes in newborn's cord blood lymphocyte subpopulations. The EDEN study cohort

PubMed Central

2011-01-01

Background Toxicants can cross the placenta and expose the developing fetus to chemical contamination leading to possible adverse health effects, by potentially inducing alterations in immune competence. Our aim was to investigate the impacts of maternal exposure to air pollution before and during pregnancy on newborn's immune system. Methods Exposure to background particulate matter less than 10 μm in diameter (PM10) and nitrogen dioxide (NO2) was assessed in 370 women three months before and during pregnancy using monitoring stations. Personal exposure to four volatile organic compounds (VOCs) was measured in a subsample of 56 non-smoking women with a diffusive air sampler during the second trimester of pregnancy. Cord blood was analyzed at birth by multi-parameter flow cytometry to determine lymphocyte subsets. Results Among other immunophenotypic changes in cord blood, decreases in the CD4+CD25+ T-cell percentage of 0.82% (p = 0.01), 0.71% (p = 0.04), 0.88% (p = 0.02), and 0.59% (p = 0.04) for a 10 μg/m3 increase in PM10 levels three months before and during the first, second and third trimester of pregnancy, respectively, were observed after adjusting for confounders. A similar decrease in CD4+CD25+ T-cell percentage was observed in association with personal exposure to benzene. A similar trend was observed between NO2 exposure and CD4+CD25+ T-cell percentage; however the association was stronger between NO2 exposure and an increased percentage of CD8+ T-cells. Conclusions These data suggest that maternal exposure to air pollution before and during pregnancy may alter the immune competence in offspring thus increasing the child's risk of developing health conditions later in life, including asthma and allergies. PMID:22047167

Submicron particle monitoring of paving and related road construction operations.

PubMed

Freund, Alice; Zuckerman, Norman; Baum, Lisa; Milek, Debra

2012-01-01

This study identified activities and sources that contribute to ultrafine and other submicron particle exposure that could trigger respiratory symptoms in highway repair workers. Submicron particle monitoring was conducted for paving, milling, and pothole repair operations in a major metropolitan area where several highway repair workers were identified as symptomatic for respiratory illness following exposures at the 2001 World Trade Center disaster site. Exposure assessments were conducted for eight trades involved in road construction using a TSI P-Trak portable condensation particle counter. Direct readings near the workers' breathing zones and observations of activities and potential sources were logged on 7 days on 27 workers using four different models of pavers and two types of millers. Average worker exposure levels ranged from 2 to 3 times background during paving and from 1 to 4 times background during milling. During asphalt paving, average personal exposures to submicron particulates were 25,000-60,000, 28,000-70,000, and 23,000-37,000 particles/ cm(3) for paver operators, screed operators, and rakers, respectively. Average personal exposures during milling were 19,000-111,000, 28,000-81,000, and 19,000 particles/cm(3) for the large miller operators, miller screed operators, and raker, respectively. Personal peak exposures were measured up to 467,000 and 455,000 particles/cm(3) in paving and milling, respectively. Several sources of submicron particles were identified. These included the diesel and electric fired screed heaters; engine exhaust from diesel powered construction vehicles passing by or idling; raking, dumping, and paving of asphalt; exhaust from the hotbox heater; pavement dust or fumes from milling operations, especially when the large miller started and stopped; and secondhand cigarette smoke. To reduce the potential for health effects in workers, over 40 recommendations were made to control exposures, including improved maintenance of paver ventilation systems; diesel fume engineering controls; reduced idling; provision of cabs for the operators; and improved dust suppression systems on the milling machine.

Potential Uses of Biomonitoring Data: A Case Study Using the Organophosphorus Pesticides Chlorpyrifos and Malathion

PubMed Central

Barr, Dana B.; Angerer, Jürgen

2006-01-01

Background Organophosphorus pesticides such as chlorpyrifos and malathion are widely used insecticides. They do not bioaccumulate appreciably in humans and are rapidly metabolized and excreted in the urine. In nonoccupational settings, exposures to these pesticides are typically sporadic and short-lived because the pesticides tend to degrade in the environment over time; however, dietary exposures may be more chronic. Biologic monitoring has been widely used to assess exposures, susceptibility, and effects of chlorpyrifos and malathion; thus, the information base on these compounds is data rich. For biomonitoring of exposure, chlorpyrifos and malathion have been measured in blood, but most typically their urinary metabolites have been measured. For assessing early effects and susceptibility, cholinesterase and microsomal esterase activities, respectively, have been measured. Objectives Although many biologic monitoring data have been generated and published on these chemicals, their interpretation is not straightforward. For example, exposure to environmental degradates of chlorpyrifos and malathion may potentially increase f urinary metabolite levels, thus leading to overestimation of exposure. Also, the temporal nature of the exposures makes the evaluation of both exposure and effects difficult. We present an overview of the current biomonitoring and other relevant data available on exposure to chlorpyrifos and malathion and the use of these data in various environmental public health applications. PMID:17107865

CSEO – the Cigarette Smoke Exposure Ontology

PubMed Central

2014-01-01

Background In the past years, significant progress has been made to develop and use experimental settings for extensive data collection on tobacco smoke exposure and tobacco smoke exposure-associated diseases. Due to the growing number of such data, there is a need for domain-specific standard ontologies to facilitate the integration of tobacco exposure data. Results The CSEO (version 1.0) is composed of 20091 concepts. The ontology in its current form is able to capture a wide range of cigarette smoke exposure concepts within the knowledge domain of exposure science with a reasonable sensitivity and specificity. Moreover, it showed a promising performance when used to answer domain expert questions. The CSEO complies with standard upper-level ontologies and is freely accessible to the scientific community through a dedicated wiki at https://publicwiki-01.fraunhofer.de/CSEO-Wiki/index.php/Main_Page. Conclusions The CSEO has potential to become a widely used standard within the academic and industrial community. Mainly because of the emerging need of systems toxicology to controlled vocabularies and also the lack of suitable ontologies for this domain, the CSEO prepares the ground for integrative systems-based research in the exposure science. PMID:25093069

Exposure of bakery and pastry apprentices to airborne flour dust using PM2.5 and PM10 personal samplers

PubMed Central

Mounier-Geyssant, Estelle; Barthélemy, Jean-François; Mouchot, Lory; Paris, Christophe; Zmirou-Navier, Denis

2007-01-01

Background This study describes exposure levels of bakery and pastry apprentices to flour dust, a known risk factor of occupational asthma. Methods Questionnaires on work activity were completed by 286 students. Among them, 34 performed a series of two personal exposure measurements using a PM2.5 and PM10 personal sampler during a complete work shift, one during a cold ("winter") period, and the other during a hot ("summer") period. Results Bakery apprentices experience greater average PM2.5 and PM10 exposures than pastry apprentices (p < 0.006). Exposure values for both particulate fractions are greater in winter (average PM10 values among bakers = 1.10 mg.m-3 [standard deviation: 0.83]) than in summer (0.63 mg.m-3 [0.36]). While complying with current European occupational limit values, these exposures exceed the ACGIH recommendations set to prevent sensitization to flour dust (0.5 mg.m-3). Over half the facilities had no ventilation system. Conclusion Young bakery apprentices incur substantial exposure to known airways allergens, a situation that might elicit early induction of airways inflammation. PMID:17976230

Associations between cadmium exposure and neurocognitive test scores in a cross-sectional study of US adults

PubMed Central

2013-01-01

Background Low-level environmental cadmium exposure and neurotoxicity has not been well studied in adults. Our goal was to evaluate associations between neurocognitive exam scores and a biomarker of cumulative cadmium exposure among adults in the Third National Health and Nutrition Examination Survey (NHANES III). Methods NHANES III is a nationally representative cross-sectional survey of the U.S. population conducted between 1988 and 1994. We analyzed data from a subset of participants, age 20–59, who participated in a computer-based neurocognitive evaluation. There were four outcome measures: the Simple Reaction Time Test (SRTT: visual motor speed), the Symbol Digit Substitution Test (SDST: attention/perception), the Serial Digit Learning Test (SDLT) trials-to-criterion, and the SDLT total-error-score (SDLT-tests: learning recall/short-term memory). We fit multivariable-adjusted models to estimate associations between urinary cadmium concentrations and test scores. Results 5662 participants underwent neurocognitive screening, and 5572 (98%) of these had a urinary cadmium level available. Prior to multivariable-adjustment, higher urinary cadmium concentration was associated with worse performance in each of the 4 outcomes. After multivariable-adjustment most of these relationships were not significant, and age was the most influential variable in reducing the association magnitudes. However among never-smokers with no known occupational cadmium exposure the relationship between urinary cadmium and SDST score (attention/perception) was significant: a 1 μg/L increase in urinary cadmium corresponded to a 1.93% (95%CI: 0.05, 3.81) decrement in performance. Conclusions These results suggest that higher cumulative cadmium exposure in adults may be related to subtly decreased performance in tasks requiring attention and perception, particularly among those adults whose cadmium exposure is primarily though diet (no smoking or work based cadmium exposure). This association was observed among exposure levels that have been considered to be without adverse effects and these levels are common in U.S. adults. Thus further research into the potential neurocognitive effects of cadmium exposure is warranted. Because cumulative cadmium exposure may mediate some of the effects of age and smoking on cognition, adjusting for these variables may result in the underestimation of associations with cumulative cadmium exposure. Prospective studies that include never-smokers and non-occupationally exposed individuals are needed to clarify these issues. PMID:23379984

Associations between serum levels of Polybrominated Diphenyl Ether (PBDE) flame retardants and environmental and behavioral factors in pregnant women

PubMed Central

Buttke, Danielle E.; Wolkin, Amy; Stapleton, Heather M.; Miranda, Marie Lynn

2015-01-01

Background Polybrominated diphenyl ethers (PBDE) are flame retardants that were previously used in upholstery, fabrics, and household appliances. PBDEs have been linked to adverse health outcomes, including neurotoxicity, thyroid hormone dysregulation, endocrine disruption, and poor semen quality. Because PBDEs pass into placental circulation, maternal exposures can approximate fetal exposures. Objectives Our objectives were to determine if diet and specific human behaviors were significantly associated with PBDE exposures in a cohort of pregnant women. Methods Women between the 34th and 38th week of pregnancy were given a questionnaire about behavioral, environmental, and dietary factors and asked to provide blood samples. Serum PBDE levels were measured using GS-MS and lipid adjusted. An adjusted ordinary least squares regression model was run to identify potential associations between behaviors and serum PBDE levels. Results Serum concentrations of BDEs 47, 99, 100, and 153 were found above the limit of detection in at least 50% of study participants and used in our models. Associations with serum PBDEs were observed with self-reported hand-to-mouth behaviors, including biting nails and licking fingers. Serum BDE levels of 47, 99, 153, and total PBDEs were also significantly higher in those individuals owning a large screen TV compared to those who did not. Serum PBDE levels were comparable to levels reported in the general population. Conclusions Hand-to-mouth behaviors may influence serum PBDE concentrations in adults. Household electronics such as large-screen TV’s appear to serve as a significant source of PBDEs in pregnant women. Together, hand-to-mouth behaviors and TV ownership may serve as a route of exposure to PBDEs in adults. PMID:22760441

Blood levels do not predict behavioral or physiological effects of Δ9-tetrahydrocannabinol in rhesus monkeys with different patterns of exposure

PubMed Central

Ginsburg, Brett C.; Hruba, Lenka; Zaki, Armia; Javors, Martin; McMahon, Lance R.

2014-01-01

Background Recent changes in the legality of cannabis have prompted evaluation of whether blood levels of Δ9-tetrahydrocannabinol (THC) or its metabolites could be used to substantiate impairment, particularly related to behavioral tasks such as driving. However, because marked tolerance develops to behavioral effects of THC, the applicability of a particular threshold of blood THC as an index of impairment in people with different patterns of use remains unclear. Studies relevant to this issue are difficult to accomplish in humans, as prior drug exposure is difficult to control. Methods Here, effects of THC to decrease rectal temperature and operant response rate compared to levels of THC and its metabolites were studied in blood in two groups of monkeys: one received intermittent treatment with THC (0.1 mg/kg i.v.) and another received chronic THC (1 mg/kg/12 h s.c.) for several years. Results In monkeys with intermittent THC exposure, a single dose of THC (3.2 mg/kg s.c.) decreased rectal temperature and response rate. The same dose did not affect response rate or rectal temperature in chronically exposed monkeys, indicative of greater tolerance. In both groups, blood levels of THC peaked 20–60 min post-injection and had a similar half life of elimination, indicating no tolerance to the pharmacokinetics of THC. Notably, in both groups, the behavioral effects of THC were not apparent when blood levels were maximal (20-min post-administration). Conclusion These data indicate that thresholds for blood levels of THC do not provide a consistent index of behavioral impairment across individuals with different patterns of THC exposure. PMID:24703610

Low-background Gamma Spectroscopy at Sanford Underground Laboratory

NASA Astrophysics Data System (ADS)

Chiller, Christopher; Alanson, Angela; Mei, Dongming

2014-03-01

Rare-event physics experiments require the use of material with unprecedented radio-purity. Low background counting assay capabilities and detectors are critical for determining the sensitivity of the planned ultra-low background experiments. A low-background counting, LBC, facility has been built at the 4850-Level Davis Campus of the Sanford Underground Research Facility to perform screening of material and detector parts. Like many rare event physics experiments, our LBC uses lead shielding to mitigate background radiation. Corrosion of lead brick shielding in subterranean installations creates radon plate-out potential as well as human risks of ingestible or respirable lead compounds. Our LBC facilities employ an exposed lead shield requiring clean smooth surfaces. A cleaning process of low-activity silica sand blasting and borated paraffin hot coating preservation was employed to guard against corrosion due to chemical and biological exposures. The resulting lead shield maintains low background contribution integrity while fully encapsulating the lead surface. We report the performance of the current LBC and a plan to develop a large germanium well detector for PMT screening. Support provided by Sd governors research center-CUBED, NSF PHY-0758120 and Sanford Lab.

Characterization and risk of exposure to elements from artisanal gold mining operations in the Bolivian Andes.

PubMed

Pavilonis, Brian; Grassman, Jean; Johnson, Glen; Diaz, Yilmael; Caravanos, Jack

2017-04-01

Artisanal and small-scale gold mining (ASGM) offers low-skilled workers an opportunity to elevate themselves out of poverty. However, this industry operates with little to no pollution controls and the cost to the environment and human health can be large. The objectives of this study were to measure levels of arsenic (As), manganese (Mn), cobalt (Co), lead (Pb), and mercury (Hg) in the environment and characterize health risks to miners and residents in an area with active ASGM operations. An exposure assessment was conducted at two different mining sites and a nearby village in the Bolivian Anders. The resulting measurements were then used to quantify cancerous and noncancerous health risks to children and adults working at and living near ASGM areas. Soil concentrations of As were well above background levels and showed great variations between the village and mining area. Mercury vapor levels at the two mining sites were approximately 30 times larger than the EPA reference concentration. The risk of developing non-cancerous health effects were primarily due to exposure to As and Hg. The probability of individuals developing cancer was considerably increased with adult miners having a probability of 1.3 out of 100. Cancer potential was driven by exposure to As, with de minimus cancer risk from all other elements. Based on the environmental characterization of elements in soils and Hg vapors, the risk of developing cancerous and non-cancerous health outcomes were above a level of concern based on EPA risk assessment guidance. Personal protective equipment was not worn by workers and Hg amalgam is commonly heated in workers' homes. Better education of the risks of ASGM is needed as well as simple controls to reduce exposure. Published by Elsevier Inc.

“Estimating Regional Background Air Quality using Space/Time Ordinary Kriging to Support Exposure Studies”

EPA Science Inventory

Local-scale dispersion models are increasingly being used to perform exposure assessments. These types of models, while able to characterize local-scale air quality at increasing spatial scale, however, lack the ability to include background concentration in their overall estimat...

Parental exposure to natural mixtures of persistent organic pollutants (POP) induced changes in transcription of apoptosis-related genes in offspring zebrafish embryos.

PubMed

Lyche, Jan L; Grześ, Irena M; Karlsson, Camilla; Nourizadeh-Lillabadi, Rasoul; Aleström, Peter; Ropstad, Erik

2016-01-01

Apoptosis is an integral element of development that may also be initiated by environmental contaminants. The aim of the present study was to assess potential changes in the regulation of apoptotic genes in zebrafish embryos following parental exposure to two natural mixtures of persistent organic pollutants (POP). The mixture from Lake Mjøsa contained exceptionally high concentrations of polybrominated diphenyl ethers (PBDE), as well as relatively high levels of polychlorinated biphenyls (PCB) and dichlorodiphenyltrichloroethane (DDT). The mixture from Lake Losna contained background concentrations of POP. Genes involved in the apoptotic machinery were screened for their expression profile at four time points during embryonic development. Thirteen and 15 genes involved in apoptosis were found to be significantly upregulated in the high-exposure and background exposure groups, respectively, compared with controls. Modulation of apoptotic genes was restricted only to the first time point, which corresponds with the blastula stage. Although there were substantial differences in POP concentrations between mixtures, genes underlying the apoptosis process showed almost similar responses to the two mixtures. In both exposure groups the main executors of apoptosis p53, casp 2, casp 6, cassp 8, and BAX displayed upregulation compared to controls, suggesting that these POP induce apoptosis via a p53-dependent mechanism. Upregulation of genes that play a critical role in apoptosis suggests that disturbance of normal apoptotic signaling during gametogenesis and embryogenesis may be one of the central mechanisms involved in adverse reproductive effects produced by POP in zebrafish.

Environmental Tobacco Smoke Exposure and Periodontitis Prevalence among Non-smokers in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

PubMed Central

Akinkugbe, Aderonke A.; Sanders, Anne E.; Preisser, John S.; Cai, Jianwen; Salazar, Christian R.; Beck, James D.

2016-01-01

Objective To describe self-reported exposure to environmental tobacco smoke (ETS) and its association with periodontitis prevalence in a diverse group of Hispanics/Latinos. Methods Data came from 8,675 lifetime non-smokers in the 2008–2011 Hispanic Community Health Study/Study of Latinos. Exposure to ETS was self-reported while periodontitis was defined using the CDC/AAP criteria and the proportion of sites affected by clinical attachment level of ≥3mm or pocket depth of ≥4mm. Survey logistic regression estimated prevalence odds ratios (POR) and 95% confidence intervals (CI). In addition, we assessed whether greater hours of exposure to ETS in the past year was associated with greater periodontitis prevalence and lastly, we conducted a simple sensitivity analysis of ETS misclassification. Results Age-standardized prevalence estimates (95% CI) for ETS exposure and periodontitis were 57.6% (55.9, 59.4) and 39.8% (38.1, 41.4) respectively. After adjusting for confounders and periodontitis risk factors, we estimated an overall adjusted POR (95% CI) for the ETS-periodontitis association as 1.09 (0.95–1.26) with a confidence limit ratio (CLR) of 1.34. This association varied in magnitude by Hispanic/Latino background, ranging from 1.04 (0.75, 1.43 with a CLR=1.91) among Central-Americans to 1.76 (1.16, 2.66 with a CLR=2.29) in Puerto Ricans. Conclusions Previously reported associations between ETS and periodontitis appear weak in this study. However, the magnitude of the association differs according to Hispanic/Latino background. PMID:27978596

Impact of occupational carcinogens on lung cancer risk in a general population

PubMed Central

De Matteis, Sara; Consonni, Dario; Lubin, Jay H; Tucker, Margaret; Peters, Susan; Vermeulen, Roel CH; Kromhout, Hans; Bertazzi, Pier Alberto; Caporaso, Neil E; Pesatori, Angela C; Wacholder, Sholom; Landi, Maria Teresa

2012-01-01

Background Exposure to occupational carcinogens is an important preventable cause of lung cancer. Most of the previous studies were in highly exposed industrial cohorts. Our aim was to quantify lung cancer burden attributable to occupational carcinogens in a general population. Methods We applied a new job–exposure matrix (JEM) to translate lifetime work histories, collected by personal interview and coded into standard job titles, into never, low and high exposure levels for six known/suspected occupational lung carcinogens in the Environment and Genetics in Lung cancer Etiology (EAGLE) population-based case–control study, conducted in Lombardy region, Italy, in 2002–05. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in men (1537 cases and 1617 controls), by logistic regression adjusted for potential confounders, including smoking and co-exposure to JEM carcinogens. The population attributable fraction (PAF) was estimated as impact measure. Results Men showed an increased lung cancer risk even at low exposure to asbestos (OR: 1.76; 95% CI: 1.42–2.18), crystalline silica (OR: 1.31; 95% CI: 1.00–1.71) and nickel–chromium (OR: 1.18; 95% CI: 0.90–1.53); risk increased with exposure level. For polycyclic aromatic hydrocarbons, an increased risk (OR: 1.64; 95% CI: 0.99–2.70) was found only for high exposures. The PAFs for any exposure to asbestos, silica and nickel–chromium were 18.1, 5.7 and 7.0%, respectively, equivalent to an overall PAF of 22.5% (95% CI: 14.1–30.0). This corresponds to about 1016 (95% CI: 637–1355) male lung cancer cases/year in Lombardy. Conclusions These findings support the substantial role of selected occupational carcinogens on lung cancer burden, even at low exposures, in a general population. PMID:22467291

Impact of UVA exposure on psychological parameters and circulating serotonin and melatonin

PubMed Central

Gambichler, Thilo; Bader, Armin; Vojvodic, Mirjana; Bechara, Falk G; Sauermann, Kirsten; Altmeyer, Peter; Hoffmann, Klaus

2002-01-01

Background People tend to feel better after exposure to ultraviolet (UV) radiation. This study was performed to investigate the impact of UVA exposure on psychological and neuroendocrine parameters. Methods Fifty-three volunteers were separated into 42 individuals who had UVA exposure and 11 individuals who had no UVA exposure. The UVA-exposed volunteers had irradiation sessions six times in a three-week period. All volunteers completed two questionnaires at baseline (T1) and at the end of the study (T3). For the determination of serotonin and melatonin serum levels of all volunteers blood samples were collected at baseline (T1), after the first UVA exposure (T2), and at the end of the study after the sixth exposure (T3). Results UVA-exposed volunteers felt significantly more balanced, less nervous, more strengthened, and more satisfied with their appearance at T3. By contrast, the controls did not show significant changes of psychological parameters. In comparison to T1 and T3, serum serotonin was significantly higher and the serum melatonin was significantly lower for the volunteers exposed to UVA at T2. Both, for exposed and non-exposed volunteers serotonin and melatonin levels did not significantly differ at T1 and T3. Conclusions It remains obscure, whether the exposure to UVA or other components of the treatment were responsible for the psychological benefits observed. The changes of circulating neuroendocrine mediators found after UVA exposure at T2 may be due to an UVA-induced effect via a cutaneous pathway. Nevertheless, the positive psychological effects observed in our study cannot be attributed to circulating serotonin or melatonin. PMID:11952999

Indoor dust and air concentrations of endotoxin in urban and rural environments.

PubMed

Barnig, C; Reboux, G; Roussel, S; Casset, A; Sohy, C; Dalphin, J-C; de Blay, F

2013-03-01

Rural dairy farming is associated with high exposure to indoor endotoxins as compared to rural nonfarming houses and urban houses. The time spent on the mattress (7 h for an adult) and of the proximity of the contaminated source should be taken into account with the other causes of exposure. Studies in European children from a farming background have shown that these children have a reduced risk of asthma and atopic sensitization compared to their urban counterparts. It has been suggested that this might be due to exposure to high levels of endotoxin in the farming environment. The aim of this study was to compare indoor endotoxin concentrations in air and dust samples from randomly selected urban and rural dwellings. In the rural area, endotoxins were analysed in farmhouses and nonfarmhouses as well as housing characteristics, lifestyle factors and agricultural practices likely to influence air and dust endotoxin levels. Endotoxin levels were significantly higher in floor (6600 ± 6100 vs 3600 ± 5600 and 3800 ± 17,000 ng g⁻¹; P < 0·001) and mattress dust (2900 ± 4100 vs 1100 ± 2400 and 800 ± 2600 ng g⁻¹; P < 0·001) from farmhouses compared to other rural and urban homes. However, no difference was observed between endotoxin concentrations in the air of urban and rural houses, and airborne endotoxin levels did not correlate to dust levels. Lack of ventilation and direct entry into the house were correlated with an increase in dust endotoxin levels. These results confirm that dairy farming is associated with high exposure to endotoxins in indoor dust samples. No difference was observed between indoor airborne concentrations between urban and rural houses. These results suggest that measuring endotoxin in dust is the most relevant method to assess endotoxin exposure. © 2012 The Society for Applied Microbiology.

The exposure of the hybrid detector of the Pierre Auger Observatory

NASA Astrophysics Data System (ADS)

Abreu, P.; Aglietta, M.; Ahn, E. J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antičić, T.; Anzalone, A.; Aramo, C.; Arganda, E.; Arisaka, K.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Bäcker, T.; Badagnani, D.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; Benzvi, S.; Berat, C.; Bergmann, T.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Busca, N. G.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chudoba, J.; Clay, R. W.; Colombo, E.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Domenico, M.; de Donato, C.; de Jong, S. J.; de La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; de Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; Del Peral, L.; Deligny, O.; Della Selva, A.; Dembinski, H.; Denkiewicz, A.; di Giulio, C.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Dobrigkeit, C.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Ferrero, A.; Fick, B.; Filevich, A.; Filipčič, A.; Fleck, I.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fröhlich, U.; Fuchs, B.; Fulgione, W.; Gamarra, R. F.; Gambetta, S.; García, B.; García Gámez, D.; Garcia-Pinto, D.; Garrido, X.; Gascon, A.; Gelmini, G.; Gemmeke, H.; Gesterling, K.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gonçalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Góra, D.; Gorgi, A.; Gouffon, P.; Gozzini, S. R.; Grashorn, E.; Grebe, S.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horneffer, A.; Hrabovský, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jiraskova, S.; Kadija, K.; Kaducak, M.; Kampert, K. H.; Karhan, P.; Karova, T.; Kasper, P.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lautridou, P.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; McEwen, M.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Meurer, C.; Mičanović, S.; Micheletti, M. I.; Miller, W.; Miramonti, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostafá, M.; Mueller, S.; Muller, M. A.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nhung, P. T.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Nyklicek, M.; Oehlschläger, J.; Olinto, A.; Oliva, P.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Parrisius, J.; Parsons, R. D.; Pastor, S.; Paul, T.; Pavlidou, V.; Payet, K.; Pech, M.; PeĶala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.; Phan, N.; Piegaia, R.; Pierog, T.; Pimenta, M.; Pirronello, V.; Platino, M.; Ponce, V. H.; Pontz, M.; Privitera, P.; Prouza, M.; Quel, E. J.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rivière, C.; Rizi, V.; Robledo, C.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-D'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Salamida, F.; Salazar, H.; Salina, G.; Sánchez, F.; Santander, M.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schroeder, F.; Schulte, S.; Schüssler, F.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Semikoz, D.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Stapleton, J.; Stasielak, J.; Stephan, M.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Tamashiro, A.; Tapia, A.; Tarutina, T.; Taşcău, O.; Tcaciuc, R.; Tcherniakhovski, D.; Tegolo, D.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tiwari, D. K.; Tkaczyk, W.; Todero Peixoto, C. J.; Tomé, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; Vargas Cárdenas, B.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Venters, T.; Verzi, V.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Warner, D.; Watson, A. A.; Weidenhaupt, K.; Weindl, A.; Westerhoff, S.; Whelan, B. J.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Winders, L.; Winnick, M. G.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Ziolkowski, M.; Pierre Auger Collaboration

2011-01-01

The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays. It consists of a surface array to measure secondary particles at ground level and a fluorescence detector to measure the development of air showers in the atmosphere above the array. The "hybrid" detection mode combines the information from the two subsystems. We describe the determination of the hybrid exposure for events observed by the fluorescence telescopes in coincidence with at least one water-Cherenkov detector of the surface array. A detailed knowledge of the time dependence of the detection operations is crucial for an accurate evaluation of the exposure. We discuss the relevance of monitoring data collected during operations, such as the status of the fluorescence detector, background light and atmospheric conditions, that are used in both simulation and reconstruction.

The exposure of the hybrid detector of the Pierre Auger Observatory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2010-06-01

The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays. It consists of a surface array to measure secondary particles at ground level and a fluorescence detector to measure the development of air showers in the atmosphere above the array. The 'hybrid' detection mode combines the information from the two subsystems. We describe the determination of the hybrid exposure for events observed by the fluorescence telescopes in coincidence with at least one water-Cherenkov detector of the surface array. A detailed knowledge of the time dependence of the detection operations is crucial for an accurate evaluation of the exposure.more » We discuss the relevance of monitoring data collected during operations, such as the status of the fluorescence detector, background light and atmospheric conditions, that are used in both simulation and reconstruction.« less

Long-Term Mental Health among Low-Income, Minority Women Following Exposure to Multiple Natural Disasters in Early and Late Adolescence Compared to Adulthood

ERIC Educational Resources Information Center

Jacobs, Marni B.; Harville, Emily W.

2015-01-01

Background: High impact experiences following a natural disaster have been shown to influence later psychopathology. Individual-level factors such as age may also contribute to a disaster's impact on mental health, though it is unclear whether young age confers a protective effect or represents a period of increased risk as compared to adulthood.…

Effects of lead exposure on oxidative stress biomarkers and plasma biochemistry in waterbirds in the field.

PubMed

Martinez-Haro, Monica; Green, Andy J; Mateo, Rafael

2011-05-01

Medina lagoon in Andalusia has one of the highest densities of spent lead (Pb) shot in Europe. Blood samples from waterbirds were collected in 2006-2008 to measure Pb concentration (PbB), δ-aminolevulinic acid dehydratase (ALAD), oxidative stress biomarkers and plasma biochemistry. PbB above background levels (>20 μg/dl) was observed in 19% (n=59) of mallards (Anas platyrhynchos) and in all common pochards (Aythya ferina) (n=4), but common coots (Fulica atra) (n=37) and moorhens (Gallinula chloropus) (n=12) were all <20 μg/dl. ALAD ratio in mallards and coots decreased with PbB levels >6 μg/dl. In mallards, an inhibition of glutathione peroxidase (GPx) and an increased level of oxidized glutathione (oxGSH) in red blood cells (RBC) were associated with PbB levels >20 μg/dl. In coots, PbB levels were negatively related to vitamin A and carotenoid levels in plasma, and total glutathione in RBCs; and positively related with higher superoxide dismutase and GPx activities and % oxGSH in RBCs. Overall, the results indicate that previously assumed background levels of PbB for birds need to be revised. Copyright © 2011 Elsevier Inc. All rights reserved.

Risk Assessment for Children Exposed to Arsenic on Baseball Fields with Contaminated Fill Material

PubMed Central

Ferguson, Alesia C.; Black, Jennifer C.; Sims, Isaac B.; Welday, Jennifer N.; Elmir, Samir M.; Goff, Kendra F.; Higginbotham, J. Mark

2018-01-01

Children can be exposed to arsenic through play areas which may have contaminated fill material from historic land use. The objective of the current study was to evaluate the risk to children who play and/or spend time at baseball fields with soils shown to have arsenic above background levels. Arsenic in soils at the study sites located in Miami, FL, USA showed distinct distributions between infield, outfield, and areas adjacent to the fields. Using best estimates of exposure factors for children baseball scenarios, results show that non-cancer risks depend most heavily upon the age of the person and the arsenic exposure level. For extreme exposure scenarios evaluated in this study, children from 1 to 2 years were at highest risk for non-cancer effects (Hazard Quotient, HQ > 2.4), and risks were higher for children exhibiting pica (HQ > 9.7) which shows the importance of testing fill for land use where children may play. At the study sites, concentration levels of arsenic resulted in a range of computed cancer risks that differed by a factor of 10. In these sites, the child’s play position also affected risk. Outfield players, with a lifetime exposure to these arsenic levels, could have 10 times more increased chance of experiencing cancers associated with arsenic (i.e., lung, bladder, skin) in comparison to infielders. The distinct concentration distributions observed between these portions of the baseball fields emphasize the need to delineate contaminated areas in public property where citizens may spend more free time. This study also showed a need for more tools to improve the risk estimates for child play activities. For instance, more refined measurements of exposure factors for intake (e.g., inhalation rates under rigorous play activities, hand to mouth rates), exposure frequency (i.e., time spent in various activities) and other exposure factors (e.g., soil particulate emission rates at baseball play fields) can help pinpoint risk on baseball fields where arsenic levels may be a concern. PMID:29300352

Challenges in estimating the health impact of Hurricane Sandy using macro-level flood data.

NASA Astrophysics Data System (ADS)

Lieberman-Cribbin, W.; Liu, B.; Schneider, S.; Schwartz, R.; Taioli, E.

2016-12-01

Background: Hurricane Sandy caused extensive physical and economic damage but the long-term health impacts are unknown. Flooding is a central component of hurricane exposure, influencing health through multiple pathways that unfold over months after flooding recedes. This study assesses concordance in Federal Emergency Management (FEMA) and self-reported flood exposure after Hurricane Sandy to elucidate discrepancies in flood exposure assessments. Methods: Three meter resolution New York State flood data was obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. FEMA data was compared to self-reported flood data obtained through validated questionnaires from New York City and Long Island residents following Sandy. Flooding was defined as both dichotomous and continuous variables and analyses were performed in SAS v9.4 and ArcGIS 10.3.1. Results: There was a moderate agreement between FEMA and self-reported flooding (Kappa statistic 0.46) and continuous (Spearman's correlation coefficient 0.50) measures of flood exposure. Flooding was self-reported and recorded by FEMA in 23.6% of cases, while agreement between the two measures on no flooding was 51.1%. Flooding was self-reported but not recorded by FEMA in 8.5% of cases, while flooding was not self-reported but indicated by FEMA in 16.8% of cases. In this last instance, 84% of people (173/207; 83.6%) resided in an apartment (no flooding reported). Spatially, the most concordance resided in the interior of New York City / Long Island, while the greatest areas of discordance were concentrated in the Rockaway Peninsula and Long Beach, especially among those living in apartments. Conclusions: There were significant discrepancies between FEMA and self-reported flood data. While macro-level FEMA flood data is a relatively less expensive and faster way to provide exposure estimates spanning larger geographic areas affected by Hurricane Sandy than micro-level estimates from cohort studies, macro-level exposure estimates may underestimate the full flooding and health impacts of the hurricane. Future disaster preparedness efforts must integrate micro and macro-level flood exposures to produce the most accurate evaluation of health impacts in affected populations.

Effects of systematic cue exposure through virtual reality on cigarette craving.

PubMed

Pericot-Valverde, Irene; Secades-Villa, Roberto; Gutiérrez-Maldonado, José; García-Rodríguez, Olaya

2014-11-01

Cigarette cravings have been associated with less successful attempts to quit smoking and a greater likelihood of relapse after smoking cessation. Background craving refers to a relatively steady and continuous experience of craving, while cue-induced craving refers to phases of intense craving triggered by cues associated with smoking. Cue exposure treatment (CET) involves repeated exposure to stimuli associated with substance use in order to reduce craving responses. However, mixed results have been found regarding the effect of CET on both types of craving. The aim of this study was to assess the effect of systematic virtual reality cue exposure treatment (VR-CET) on background and cue-induced cravings. Participants were 48 treatment-seeking smokers. The VR-CET consisted of prolonged exposure sessions to several interactive virtual environments. The VR-CET was applied once a week over 5 weeks. An individualized hierarchy of exposure was drawn up for each patient starting from the easiest virtual environment. Background and cue-induced cravings were recorded in each session. Cue-induced craving decreased over each session as a result of prolonged exposure. VR-CET also reduced cue-induced and background cravings across the 5 sessions, showing a cumulative effect across the exposure sessions. Our results evidenced the utility of VR-CET in reducing both types of cigarette craving. A combination of CET through VR with psychological treatments may improve current treatments for smoking cessation. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Child voice and noise: a pilot study of noise in day cares and the effects on 10 children's voice quality according to perceptual evaluation.

PubMed

McAllister, Anita M; Granqvist, Svante; Sjölander, Peta; Sundberg, Johan

2009-09-01

The purpose of this investigation was to study children's exposure to background noise at the ears during a normal day at the day care center and also to relate this to a perceptual evaluation of voice quality. Ten children, from three day care centers, with no history of hearing and speech problems or frequent infections were selected as subjects. A binaural recording technique was used with two microphones placed on both sides of the subject's head, at equal distance from the mouth. A portable digital audio tape (DAT) recorder (Sony TCD-D 100, Stockholm, Sweden) was attached to the subject's waist. Three recordings were made for each child during the day. Each recording was calibrated and started with three repetitions of three sentences containing only sonorants. The recording technique allowed separate analyses of the background noise level and of the sound pressure level (SPL) of each subjects' own voice. Results showed a mean background noise level for the three day care centers at 82.6dBA Leq, ranging from 81.5 to 83.6dBA Leq. Day care center no. 2 had the highest mean value and also the highest value at any separate recording session with a mean background noise level of 85.4dBA Leq during the noontime recordings. Perceptual evaluation showed that the children attending this day care center also received higher values on the following voice characteristics: hoarseness, breathiness, and hyperfunction. Girls increased their loudness level during the day, whereas for boys no such change could be observed.

Environmental exposure to human carcinogens in teenagers and the association with DNA damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Franken, Carmen, E-mail: carmen.franken@vito.be

Background: We investigated whether human environmental exposure to chemicals that are labeled as (potential) carcinogens leads to increased (oxidative) damage to DNA in adolescents. Material and methods: Six hundred 14–15-year-old youngsters were recruited all over Flanders (Belgium) and in two areas with important industrial activities. DNA damage was assessed by alkaline and formamidopyrimidine DNA glycosylase (Fpg) modified comet assays in peripheral blood cells and analysis of urinary 8-hydroxydeoxyguanosine (8-OHdG) levels. Personal exposure to potentially carcinogenic compounds was measured in urine, namely: chromium, cadmium, nickel, 1-hydroxypyrene as a proxy for exposure to other carcinogenic polycyclic aromatic hydrocarbons (PAHs), t,t-muconic acid asmore » a metabolite of benzene, 2,5-dichlorophenol (2,5-DCP), organophosphate pesticide metabolites, and di(2-ethylhexyl) phthalate (DEHP) metabolites. In blood, arsenic, polychlorinated biphenyl (PCB) congeners 118 and 156, hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT) and perfluorooctanoic acid (PFOA) were analyzed. Levels of methylmercury (MeHg) were measured in hair. Multiple linear regression models were used to establish exposure-response relationships. Results: Biomarkers of exposure to PAHs and urinary chromium were associated with higher levels of both 8-OHdG in urine and DNA damage detected by the alkaline comet assay. Concentrations of 8-OHdG in urine increased in relation with increasing concentrations of urinary t,t-muconic acid, cadmium, nickel, 2,5-DCP, and DEHP metabolites. Increased concentrations of PFOA in blood were associated with higher levels of DNA damage measured by the alkaline comet assay, whereas DDT was associated in the same direction with the Fpg-modified comet assay. Inverse associations were observed between blood arsenic, hair MeHg, PCB 156 and HCB, and urinary 8-OHdG. The latter exposure biomarkers were also associated with higher fish intake. Urinary nickel and t,t-muconic acid were inversely associated with the alkaline comet assay. Conclusion: This cross-sectional study found associations between current environmental exposure to (potential) human carcinogens in 14–15-year-old Flemish adolescents and short-term (oxidative) damage to DNA. Prospective follow-up will be required to investigate whether long-term effects may occur due to complex environmental exposures. - Highlights: • Exposure to (potential) carcinogens is associated with (oxidative) damage to DNA. • Most associations of exposures are with urinary 8-OHdG. • 1-Hydroxypyrene and chromium are associated with the comet assay and 8-OHdG. • PFOA is associated with higher levels of DNA damage in the alkaline comet assay.« less

Formaldehyde Exposure and Lower Respiratory Infections in Infants: Findings from the PARIS Cohort Study

PubMed Central

Roda, Célina; Kousignian, Isabelle; Guihenneuc-Jouyaux, Chantal; Dassonville, Claire; Nicolis, Ioannis; Just, Jocelyne

2011-01-01

Background: Certain chemical pollutants can exacerbate lower respiratory tract infections (LRIs), a common childhood ailment. Although formaldehyde (FA) is one of the most common air pollutants found in indoor environments, its impact on infant health is uncertain. Objective: Our aim was to determine the impact of FA exposure on the LRI incidence during the first year of life of infants from the Pollution and Asthma Risk: an Infant Study (PARIS) birth cohort. Methods: FA was measured in a random sample of 196 infants’ dwellings, and exposure to this pollutant was estimated for 2,940 infants using predictive models based on measurements and data about potential determinants of FA levels. Health data were collected from parents by regular self-administered questionnaires. We used multivariate logistic regressions to estimate associations between FA exposure and the occurrence of LRI and wheezy LRI (wLRI), adjusting for potential confounders/risk factors. Results: During the first year of life, 45.8% of infants had at least one LRI, and LRI occurred simultaneously with wheezing in 48.7% of cases. The FA predictive models correctly classified 70% of dwellings as having high or low exposure, and we estimated that 43.3% of infants were exposed throughout the first year to levels of FA > 19.5 µg/m3. FA exposure was significantly associated with LRI and wLRI before and after adjustment for known LRI risk factors/confounders. For an interquartile increase in FA levels (12.4 μg/m3), we estimated a 32% [95% confidence interval (CI): 11, 55] and 41% (95% CI: 14, 74) increase in the incidence of LRI and wLRI, respectively. Conclusion: The findings of this study suggest that infants exposed to FA at an early age have an increased incidence of LRI. PMID:21810553

Biomonitoring of cadmium, chromium, nickel and arsenic in general population living near mining and active industrial areas in Southern Tunisia.

PubMed

Khlifi, Rim; Olmedo, Pablo; Gil, Fernando; Feki-Tounsi, Molka; Hammami, Bouthaina; Rebai, Ahmed; Hamza-Chaffai, Amel

2014-02-01

The human health impact of the historic and current mining and industrial activities in Tunisia is not known. This study assessed the exposure to metals in the population of Southern Tunisia, using biomonitoring. The aim of this pilot study was to evaluate metal exposure on 350 participants living near mining and active industrial areas in the South of Tunisia. Blood specimens were analyzed for metals (Cd, Cr, As, and Ni) by Atomic Absorption Spectrometer equipped with Zeeman background correction and AS-800 auto sampler by graphite furnace and graphite tubes with integrated L'vov platform. The sample population was classified according to different age groups, sex, smoking habit, sea food and water drinking consumption, occupational exposure, amalgam fillings and place of residence. The blood As, Cd, Cr and Ni values expressed as mean ± SD were 1.56 ± 2.49, 0.74 ± 1.15, 35.04 ± 26.02 and 30.56 ± 29.96 μg/l, respectively. Blood Cd and Ni levels in smokers were 2 and 1.2 times, respectively, higher than in non-smokers. Blood Cd levels increase significantly with age (p = 0.002). As, Cd and Ni were significantly correlated with gender and age (p < 0.05). Cd level in blood samples of subjects occupationally exposed was 1.3 times higher than that of non-exposed. Blood metals were not significantly affected by amalgam fillings, place of living and sea food and drinking water consumption. This first biomonitoring study of metal exposure in the South of Tunisia reveals a substantial exposure to several metals. The pathways of exposure and health significance of these findings need to be further investigated.

Environmental Mold and Mycotoxin Exposures Elicit Specific Cytokine and Chemokine Responses

PubMed Central

Rosenblum Lichtenstein, Jamie H.; Hsu, Yi-Hsiang; Gavin, Igor M.; Donaghey, Thomas C.; Molina, Ramon M.; Thompson, Khristy J.; Chi, Chih-Lin; Gillis, Bruce S.; Brain, Joseph D.

2015-01-01

Background Molds can cause respiratory symptoms and asthma. We sought to use isolated peripheral blood mononuclear cells (PBMCs) to understand changes in cytokine and chemokine levels in response to mold and mycotoxin exposures and to link these levels with respiratory symptoms in humans. We did this by utilizing an ex vivo assay approach to differentiate mold-exposed patients and unexposed controls. While circulating plasma chemokine and cytokine levels from these two groups might be similar, we hypothesized that by challenging their isolated white blood cells with mold or mold extracts, we would see a differential chemokine and cytokine release. Methods and Findings Peripheral blood mononuclear cells (PBMCs) were isolated from blood from 33 patients with a history of mold exposures and from 17 controls. Cultured PBMCs were incubated with the most prominent Stachybotrys chartarum mycotoxin, satratoxin G, or with aqueous mold extract, ionomycin, or media, each with or without PMA. Additional PBMCs were exposed to spores of Aspergillus niger, Cladosporium herbarum and Penicillium chrysogenum. After 18 hours, cytokines and chemokines released into the culture medium were measured by multiplex assay. Clinical histories, physical examinations and pulmonary function tests were also conducted. After ex vivo PBMC exposures to molds or mycotoxins, the chemokine and cytokine profiles from patients with a history of mold exposure were significantly different from those of unexposed controls. In contrast, biomarker profiles from cells exposed to media alone showed no difference between the patients and controls. Conclusions These findings demonstrate that chronic mold exposures induced changes in inflammatory and immune system responses to specific mold and mycotoxin challenges. These responses can differentiate mold-exposed patients from unexposed controls. This strategy may be a powerful approach to document immune system responsiveness to molds and other inflammation-inducing environmental agents. PMID:26010737

Impact of a smoking ban in hospitality venues on second hand smoke exposure: a comparison of exposure assessment methods

PubMed Central

2013-01-01

Background In May 2010, Switzerland introduced a heterogeneous smoking ban in the hospitality sector. While the law leaves room for exceptions in some cantons, it is comprehensive in others. This longitudinal study uses different measurement methods to examine airborne nicotine levels in hospitality venues and the level of personal exposure of non-smoking hospitality workers before and after implementation of the law. Methods Personal exposure to second hand smoke (SHS) was measured by three different methods. We compared a passive sampler called MoNIC (Monitor of NICotine) badge, to salivary cotinine and nicotine concentration as well as questionnaire data. Badges allowed the number of passively smoked cigarettes to be estimated. They were placed at the venues as well as distributed to the participants for personal measurements. To assess personal exposure at work, a time-weighted average of the workplace badge measurements was calculated. Results Prior to the ban, smoke-exposed hospitality venues yielded a mean badge value of 4.48 (95%-CI: 3.7 to 5.25; n = 214) cigarette equivalents/day. At follow-up, measurements in venues that had implemented a smoking ban significantly declined to an average of 0.31 (0.17 to 0.45; n = 37) (p = 0.001). Personal badge measurements also significantly decreased from an average of 2.18 (1.31-3.05 n = 53) to 0.25 (0.13-0.36; n = 41) (p = 0.001). Spearman rank correlations between badge exposure measures and salivary measures were small to moderate (0.3 at maximum). Conclusions Nicotine levels significantly decreased in all types of hospitality venues after implementation of the smoking ban. In-depth analyses demonstrated that a time-weighted average of the workplace badge measurements represented typical personal SHS exposure at work more reliably than personal exposure measures such as salivary cotinine and nicotine. PMID:23731820

Cancer and non-cancer health effects from food contaminant exposures for children and adults in California: a risk assessment

PubMed Central

2012-01-01

Background In the absence of current cumulative dietary exposure assessments, this analysis was conducted to estimate exposure to multiple dietary contaminants for children, who are more vulnerable to toxic exposure than adults. Methods We estimated exposure to multiple food contaminants based on dietary data from preschool-age children (2–4 years, n=207), school-age children (5–7 years, n=157), parents of young children (n=446), and older adults (n=149). We compared exposure estimates for eleven toxic compounds (acrylamide, arsenic, lead, mercury, chlorpyrifos, permethrin, endosulfan, dieldrin, chlordane, DDE, and dioxin) based on self-reported food frequency data by age group. To determine if cancer and non-cancer benchmark levels were exceeded, chemical levels in food were derived from publicly available databases including the Total Diet Study. Results Cancer benchmark levels were exceeded by all children (100%) for arsenic, dieldrin, DDE, and dioxins. Non-cancer benchmarks were exceeded by >95% of preschool-age children for acrylamide and by 10% of preschool-age children for mercury. Preschool-age children had significantly higher estimated intakes of 6 of 11 compounds compared to school-age children (p<0.0001 to p=0.02). Based on self-reported dietary data, the greatest exposure to pesticides from foods included in this analysis were tomatoes, peaches, apples, peppers, grapes, lettuce, broccoli, strawberries, spinach, dairy, pears, green beans, and celery. Conclusions Dietary strategies to reduce exposure to toxic compounds for which cancer and non-cancer benchmarks are exceeded by children vary by compound. These strategies include consuming organically produced dairy and selected fruits and vegetables to reduce pesticide intake, consuming less animal foods (meat, dairy, and fish) to reduce intake of persistent organic pollutants and metals, and consuming lower quantities of chips, cereal, crackers, and other processed carbohydrate foods to reduce acrylamide intake. PMID:23140444

Trauma-Related Dissociation Is Linked With Maladaptive Personality Functioning

PubMed Central

Granieri, Antonella; Guglielmucci, Fanny; Costanzo, Antonino; Caretti, Vincenzo; Schimmenti, Adriano

2018-01-01

Background: Extensive research has demonstrated the positive associations among the exposure to traumatic experiences, the levels of dissociation, and the severity of psychiatric symptoms in adults. However, it has been hypothesized in clinical literature that an excessive activation of the dissociative processes following multiple traumatic experiences may jeopardize the psychological and behavioral functioning of the individuals, fostering higher levels of maladaptive personality functioning. Methods: The study involved 322 adult volunteers from Italy. Participants completed measures on traumatic experiences, dissociation, and maladaptive personality traits. Results: The number of traumatic experiences reported by participants were positively associated with dissociation scores and maladaptive personality scores. Mediation analyses showed that dissociation acted as a partial mediator in the relationship between traumatic experiences and overall maladaptive personality functioning. Regression curve analyses showed that the positive association between maladaptive personality functioning and dissociation was stronger among participants with higher exposure to traumatic experiences. Conclusion: Exposure to multiple traumatic experiences may increase the risk for an excessive activation of the dissociative processes, which in turn may generate severe impairments in multiple domains of personality functioning. PMID:29887807

What Researchers Have Learned about Toddlers and Television

ERIC Educational Resources Information Center

Anderson, Daniel R.; Hanson, Katherine G.

2013-01-01

This article reviews research conducted after the American Academy of Pediatrics 1999 recommendation against screen exposure for children less than 2 years old. Television in the background disrupts play and parent-child interactions. Background TV exposure is associated with negative cognitive and language outcomes. Children begin to understand…

Mobile phone signal exposure triggers a hormesis-like effect in Atm+/+ and Atm-/- mouse embryonic fibroblasts.

PubMed

Sun, Chuan; Wei, Xiaoxia; Fei, Yue; Su, Liling; Zhao, Xinyuan; Chen, Guangdi; Xu, Zhengping

2016-11-18

Radiofrequency electromagnetic fields (RF-EMFs) have been classified by the International Agency for Research on Cancer as possible carcinogens to humans; however, this conclusion is based on limited epidemiological findings and lacks solid support from experimental studies. In particular, there are no consistent data regarding the genotoxicity of RF-EMFs. Ataxia telangiectasia mutated (ATM) is recognised as a chief guardian of genomic stability. To address the debate on whether RF-EMFs are genotoxic, we compared the effects of 1,800 MHz RF-EMF exposure on genomic DNA in mouse embryonic fibroblasts (MEFs) with proficient (Atm +/+ ) or deficient (Atm -/- ) ATM. In Atm +/+ MEFs, RF-EMF exposure for 1 h at an average special absorption rate of 4.0 W/kg induced significant DNA single-strand breaks (SSBs) and activated the SSB repair mechanism. This effect reduced the DNA damage to less than that of the background level after 36 hours of exposure. In the Atm -/- MEFs, the same RF-EMF exposure for 12 h induced both SSBs and double-strand breaks and activated the two repair processes, which also reduced the DNA damage to less than the control level after prolonged exposure. The observed phenomenon is similar to the hormesis of a toxic substance at a low dose. To the best of our knowledge, this study is the first to report a hormesis-like effect of an RF-EMF.

Macrofaunal recolonization of copper-contaminated sediments in San Diego Bay.

PubMed

Neira, Carlos; Mendoza, Guillermo; Porrachia, Magali; Stransky, Chris; Levin, Lisa A

2015-12-30

Effects of Cu-loading on macrofaunal recolonization were examined in Shelter Island Yacht Basin (San Diego Bay, California). Sediments with high and low Cu levels were defaunated and Cu-spiked, translocated, and then placed back into the environment. These demonstrated that the alteration observed in benthic communities associated with Cu contamination occurs during initial recolonization. After a 3-month exposure to sediments with varying Cu levels, two primary colonizing communities were identified: (1) a "mouth assemblage" resembling adjacent background fauna associated with low-Cu levels that was more diverse and predominantly dominated by surface- and subsurface-deposit feeders, burrowers, and tube builders, and (2) a "head assemblage" resembling adjacent background fauna associated with high-Cu concentrations, with few dominant species and an increasing importance of carnivores and mobile epifauna. Cu loading can cause reduced biodiversity and lower structural complexity that may last several months if high concentrations persist, with a direct effect on community functioning. Copyright © 2015 Elsevier Ltd. All rights reserved.

Histone Methylation in Nickel-Smelting Industrial Workers

PubMed Central

Ma, Li; Bai, Yana; Pu, Hongquan; Gou, Faxiang; Dai, Min; Wang, Hui; He, Jie; Zheng, Tongzhang; Cheng, Ning

2015-01-01

Background Nickel is an essential trace metal naturally found in the environment. It is also common in occupational settings, where it associates with various levels of both occupational and nonoccupational exposure In vitro studies have shown that nickel exposure can lead to intracellular accumulation of Ni2+, which has been associated with global decreases in DNA methylation, increases in chromatin condensation, reductions in H3K9me2, and elevated levels of H3K4me3. Histone modifications play an important role in modulating chromatin structure and gene expression. For example, tri-methylation of histone H3k4 has been found to be associated with transcriptional activation, and tri-methylation of H3k27 has been found to be associated with transcriptional repression. Aberrant histone modifications have been found to be associated with various human diseases, including cancer. The purpose of this work was to identify biomarkers for populations with occupational nickel exposure and to examine the relationship between histone methylation and nickel exposure. This may provide a scientific indicator of early health impairment and facilitate exploration of the molecular mechanism underlying cancer pathogenesis. Methods One hundred and forty subjects with occupational exposure to Ni and 140 referents were recruited. H3K4 and H3K27 trimethylation levels were measured in subjects’ blood cells. Results H3K4me3 levels were found to be higher in nickel smelting workers (47.24±20.85) than in office workers (22.65±8.81; P = 0.000), while the opposite was found for levels of H3K27me3(nickel smelting workers, 13.88± 4.23; office workers, 20.67± 5.96; P = 0.000). H3K4me3 was positively (r = 0.267, P = 0.001) and H3K27 was negatively (r = -0.684, P = 0.000) associated with age and length of service in smelting workers. Conclusion This study indicated that occupational exposure to Ni is associated with alterations in levels of histone modification. PMID:26474320

Effect of environmental exposure to hydrogen sulfide on central nervous system and respiratory function: a systematic review of human studies

PubMed Central

Lim, Eunjung; Mbowe, Omar; Lee, Angela S. W.; Davis, James

2016-01-01

Background Assessment of the health effects of low-level exposure to hydrogen sulfide (H2S) on humans through experiments, industrial, and community studies has shown inconsistent results. Objective To critically appraise available studies investigating the effect of H2S on the central nervous system (CNS) and on respiratory function. Methods A search was conducted in 16 databases for articles published between January 1980 and July 2014. Two researchers independently evaluated potentially relevant papers based on a set of inclusion/exclusion criteria. Results Twenty-seven articles met the inclusion criteria: 6 experimental, 12 industry-based studies, and 10 community-based studies (one article included both experimental and industry-based studies). The results of the systematic review varied by study setting and quality. Several community-based studies reported associations between day-to-day variations in H2S levels and health outcomes among patients with chronic respiratory conditions. However, evidence from the largest and better-designed community-based studies did not support that chronic, ambient H2S exposure has health effects on the CNS or respiratory function. Results from industry-based studies varied, reflecting the diversity of settings and the broad range of H2S exposures. Most studies did not have individual measurements of H2S exposure. Discussion The results across studies were inconsistent, justifying the need for further research. PMID:27128692

Biomonitoring of perfluorinated compounds in adults exposed to contaminated drinking water in the Veneto Region, Italy.

PubMed

Ingelido, Anna Maria; Abballe, Annalisa; Gemma, Simonetta; Dellatte, Elena; Iacovella, Nicola; De Angelis, Giovanna; Zampaglioni, Franco; Marra, Valentina; Miniero, Roberto; Valentini, Silvia; Russo, Francesca; Vazzoler, Marina; Testai, Emanuela; De Felip, Elena

2018-01-01

In 2013 a contamination of drinking water by perfluoroalkylated substances (PFASs) was discovered in areas of the Veneto Region (northern Italy). In this study the exposure to PFASs of people living in the aforesaid areas was characterized: contaminant serum concentrations were measured and compared with those of a control population group living in neighboring areas at background exposure (based on available drinking water data). The enrolled population was also genotyped for the OATP1A2*3 allelic variant, possibly affecting PFAS excretion and hence the internal dose. The difference in PFAS concentrations between exposed and not exposed subjects was significantly larger for nine of the 12 substances analyzed, and confirmed that water contamination had resulted in an appreciable high exposure of the residing population over time. Within the group of exposed subjects, subgroups at different exposure levels were identified. The contamination of drinking water of the residence area was found to be the main factor influencing PFAS serum levels; in addition to water contamination, other relevant influencing factors were sex, the years of residence and raising own livestock. No relationship with the genetic trait for the studied renal transporter was evidenced. These results provide a baseline characterization of PFAS exposure of the monitored population groups for further studies, planned to be carried out in the near future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cholinesterase Depression and Its Association with Pesticide Exposure across the Agricultural Season among Latino Farmworkers in North Carolina

PubMed Central

Quandt, Sara A.; Chen, Haiying; Grzywacz, Joseph G.; Vallejos, Quirina M.; Galvan, Leonardo; Arcury, Thomas A.

2010-01-01

Background Farmworkers can be exposed to a wide variety of pesticides. Assessing cholinesterase activity over time can be used to monitor exposure to organophosphorus and carbamate pesticides. Objectives The goal of this study was to document patterns and variation in cholinesterase levels across the agricultural season (May–August) among field-workers, and to explore the association of cholinesterase depression with pesticide exposure across the agricultural season. Methods Dried blood samples collected from 231 migrant farmworkers sampled from camps in eastern North Carolina up to four times across a summer agricultural season were analyzed for cholinesterase activity, and urine samples were analyzed for metabolites of organophosphorus and carbamate pesticides. Reductions of ≥ 15% from an individual’s highest value were identified and considered evidence of meaningful cholinesterase activity depression. Results The average cholinesterase activity levels were lowest in June, with significantly higher mean values in July and August. When adjusted for age, sex, minutes waited to shower, and days worked in the fields, the number of organophosphorus and carbamate pesticides detected in urine predicted reductions in cholinesterase activity. Conclusions These data demonstrate that workers are experiencing pesticide exposure. Greater enforcement of existing safety regulations or strengthening of these regulations may be warranted. This study demonstrates that serial measurements of cholinesterase activity across an agricultural season can detect exposure to pesticides among field-workers. PMID:20085857

Prenatal dichlorodiphenyldichloroethylene (DDE) exposure and child growth during the first year of life

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garced, Sheyla, E-mail: sgarced@gmail.com; Torres-Sanchez, Luisa, E-mail: ltorress@insp.mx; Cebrian, Mariano E., E-mail: mcebrian@cinvestav.mx

Background: Due to its long-term persistence in the environment and its ability to cross the placental barrier, prenatal p,p Prime -dichlorodiphenyldichloroethene (DDE) exposure continues to be a public health concern. This study aimed to evaluate the association between prenatal DDE exposure and child growth, at birth and during the first year of life. Methods: 253 pregnant women were recruited between January 2001 and June 2005 in a prospective cohort in Morelos, Mexico. Serum levels of DDE were measured during each trimester of pregnancy by gas chromatography with an electron capture detector. Using the generalized mixed-effects models, the association between DDEmore » and child growth parameters (weight-for-age, length-for-age, weight-for-length, BMI-for-age and head circumference-for-age Z-scores) from birth to 1 year of age was assessed. Maternal dietary intake was considered as covariable among others. Results: DDE levels were 6.3{+-}2.8 ng/mL (first trimester), 6.6{+-}2.9 ng/mL (second trimester), and 7.6{+-}2.9 ng/mL (third trimester). After adjusting for potential confounder variables, no significant associations were observed with prenatal DDE exposure and each of the selected parameters. Conclusions: Our results show no evidence of an association between prenatal DDE exposure and child growth during the first year of life.« less

Infants’ Exposure to Aflatoxin M1 from Mother’s Breast Milk in Iran

PubMed Central

Ghiasian, SA; Maghsood, AH

2012-01-01

Background The occurrence of aflatoxin M1 (AFM1) in milk, especially breast milk, is a valuable biomarker for exposure determination to aflatoxin B1 (AFB1). In the present study, the risk of exposure to AFM1 in infants fed breast milk was investigated. Methods: An enzyme-linked immunosorbent assay (ELISA) was used for the analysis of AFM1 in breast milk samples from 132 lactating mothers referred to four urban Mothers and Babies Care Unit of Hamadan, western Iran. Results: AFM1 was detected in eight samples (6.06%) at mean concentration of 9.45 ng/L. The minimum and maximum of concentration was 7.1 to 10.8 ng/L, respectively. Although the concentration of AFM1 in none of the samples was higher than the maximum tolerance limit accepted by USA and European Union (25 ng/kg) however, 25% had a level of AFM1 above the allowable level of Australia and Switzerland legal limit (10 ng/L). Conclusions: Lactating mothers and infants in western parts of Iran could be at risk for AFB1 and AFM1 exposure, respectively. Considering all this information, the investigation of AFM1 in lactating mothers as a biomarker for post-natal exposure of infants to this carcinogen deserves further studies in various seasons and different parts of Iran. PMID:23113156

Effects of early life exposure to ultraviolet C radiation on mitochondrial DNA content, transcription, ATP production, and oxygen consumption in developing Caenorhabditis elegans

PubMed Central

2013-01-01

Background Mitochondrial DNA (mtDNA) is present in multiple copies per cell and undergoes dramatic amplification during development. The impacts of mtDNA damage incurred early in development are not well understood, especially in the case of types of mtDNA damage that are irreparable, such as ultraviolet C radiation (UVC)-induced photodimers. Methods We exposed first larval stage nematodes to UVC using a protocol that results in accumulated mtDNA damage but permits nuclear DNA (nDNA) repair. We then measured the transcriptional response, as well as oxygen consumption, ATP levels, and mtDNA copy number through adulthood. Results Although the mtDNA damage persisted to the fourth larval stage, we observed only a relatively minor ~40% decrease in mtDNA copy number. Transcriptomic analysis suggested an inhibition of aerobic metabolism and developmental processes; mRNA levels for mtDNA-encoded genes were reduced ~50% at 3 hours post-treatment, but recovered and, in some cases, were upregulated at 24 and 48 hours post-exposure. The mtDNA polymerase γ was also induced ~8-fold at 48 hours post-exposure. Moreover, ATP levels and oxygen consumption were reduced in response to UVC exposure, with marked reductions of ~50% at the later larval stages. Conclusions These results support the hypothesis that early life exposure to mitochondrial genotoxicants could result in mitochondrial dysfunction at later stages of life, thereby highlighting the potential health hazards of time-delayed effects of these genotoxicants in the environment. PMID:23374645

Isocyanate exposure and asthma in the UK vehicle repair industry

PubMed Central

Jones, K.; Piney, M.; Agius, R. M.

2015-01-01

Background Organic diisocyanates are a common cause of occupational asthma, particularly in motor vehicle repair (MVR) workers. The UK Health & Safety Laboratory provides screening for urinary hexamethylenediamine (UHDA), a biomarker of exposure to 1,6-hexamethylene diisocyanate (HDI). The UK Surveillance of Work-related and Occupational Respiratory Disease scheme (SWORD) has collected reports of occupational asthma since 1996. Aims To compare trends in HDI exposure with trends in the incidence of work-related asthma attributed to isocyanates or paint spraying in MVR workers reported to SWORD. Methods Two-level regression models were used to estimate trends in UHDA levels and work-related asthma in MVR workers reported to SWORD. The direction and magnitude of the trends were compared descriptively. Results From 2006 to 2014, there was a significant decline in the number of urine samples with detectable levels of UHDA (odds ratio = 0.96; 95% confidence intervals 0.94–0.98) and minimal change in those over the guidance value (1.03; 1.00–1.06). Over the same period, there was a significant decline in all asthma cases attributed to isocyanates or paint spraying reported to SWORD (0.90; 0.86–0.94) and a non-significant decline among MVR workers (0.94; 0.86–1.02). Conclusions The simultaneous decrease in HDI exposure and incident cases of asthma reported to SWORD is temporally consistent with a reduction in exposure to airborne isocyanate leading to a reduction in asthma. Although this is not direct evidence of a causal relationship between the two trends, it is suggestive. PMID:26209793

Traffic-related air pollution and lung cancer: A meta-analysis

PubMed Central

Chen, Gongbo; Wan, Xia; Yang, Gonghuan; Zou, Xiaonong

2015-01-01

Background We conducted a meta-analysis to evaluate the association between traffic-related air pollution and lung cancer in order to provide evidence for control of traffic-related air pollution. Methods Several databases were searched for relevant studies up to December 2013. The quality of articles obtained was evaluated by the Strengthening the Reporting of Observational Studies in Epidemiology checklist. Statistical analysis, including pooling effective sizes and confidential intervals, was performed. Results A total of 1106 records were obtained through the database and 36 studies were included in our analysis. Among the studies included, 14 evaluated the association between ambient exposure to traffic-related air pollution and lung cancer and 22 studies involved occupational exposure to air pollution among professional drivers. Twenty-two studies were marked A level regarding quality, 13 were B level, and one was C level. Exposure to nitrogen dioxide (meta-odds ratio [OR]: 1.06, 95% confidence interval [CI]: 0.99–1.13), nitrogen oxide (meta-OR: 1.04, 95% CI: 1.01–1.07), sulfur dioxide (meta-OR: 1.03, 95% CI: 1.02–1.05), and fine particulate matter (meta-OR: 1.11, 95% CI: 1.00–1.22) were positively associated with a risk of lung cancer. Occupational exposure to air pollution among professional drivers significantly increased the incidence (meta-OR: 1.27, 95% CI: 1.19–1.36) and mortality of lung cancer (meta-OR: 1.14, 95% CI: 1.04–1.26). Conclusion Exposure to traffic-related air pollution significantly increased the risk of lung cancer. PMID:26273377

Cardiovascular effects of environmental noise: research in Germany.

PubMed

Maschke, Christian

2011-01-01

Research on systematic noise effects started in Germany back in the fifties with basic experimental studies on humans. As a result, noise was classified as a non-specific stressor, which could cause an ergotropic activation of the complete organism. In the light of this background research a hypothesis was proposed that long-term noise exposure could have an adverse effect on health. This hypothesis was further supported by animal studies. Since the sixties, the adverse effects of chronic road traffic noise exposure were further examined in humans with the help of epidemiological studies. More epidemiological aircraft noise studies followed in the 1970s and thereafter. The sample size was increased, relevant confounding factors were taken into account, and the exposure and health outcomes were investigated objectively and with higher quality measures. To date, more than 20 German epidemiological traffic noise studies have focused on noise-induced health effects, mainly on the cardiovascular system. In particular, the newer German noise studies demonstrate a clear association between residential exposure to traffic noise (particularly night noise) and cardiovascular outcomes. Nevertheless, additional research is needed, particularly on vulnerable groups and multiple noise exposures. The epidemiological findings have still not been fully considered in German regulations, particularly for aircraft noise. The findings, however, were taken into account in national recommendations. The Federal Environment Agency recommends noise rating levels of 65 dB(A) for the day and 55 dB(A) for the night, as a short-term goal. In the medium term, noise rating levels of 60 / 50 (day, night) should be reached and noise rating levels of 55 / 45 in the long run.

Widespread exposure to lead affects the body condition of free-living whooper swans Cygnus cygnus wintering in Britain.

PubMed

Newth, J L; Rees, E C; Cromie, R L; McDonald, R A; Bearhop, S; Pain, D J; Norton, G J; Deacon, C; Hilton, G M

2016-02-01

Lead poisoning, through the ingestion of spent lead gunshot, is an established cause of morbidity and mortality in waterbirds globally, but the thresholds at which blood levels begin to affect the physiology of birds in the wild are less well known. Here we determine the prevalence of lead exposure in whooper swans and, for the first time, identify the level of blood lead associated with initial reductions in body condition. Blood lead elevated above background levels (i.e. >20 μg dL(-1)) was found in 41.7% (125/300) of swans tested. Blood lead was significantly negatively associated with winter body condition when levels were ≥44 μg dL(-1) (27/260 = 10%). Our findings indicating that sub-lethal impacts of lead on body condition occur at the lower end of previously established clinical thresholds and that a relatively high proportion of individuals in this population may be affected, reaffirm the importance of reducing contamination of the environment with lead shot. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of heavy metals content in dietary supplements in Lebanon

PubMed Central

2013-01-01

Background The consumption of dietary supplements is widely spread and on the rise. These dietary supplements are generally used without prescriptions, proper counseling or any awareness of their health risk. The current study aimed at analyzing the metals in 33 samples of imported dietary supplements highly consumed by the Lebanese population, using 3 different techniques, to ensure the safety and increase the awareness of the citizen to benefit from these dietary supplements. Results Some samples had levels of metals above their maximum allowable levels (Fe: 24%, Zn: 33%, Mn: 27%, Se: 15%, Mo: 12% of samples), but did not pose any health risk because they were below permitted daily exposure limit and recommended daily allowance except for Fe in 6% of the samples. On the other hand, 34% of the samples had Cu levels above allowable limit where 18% of them were above their permitted daily exposure and recommended daily allowance. In contrast, all samples had concentration of Cr, Hg, and Pb below allowable limits and daily exposure. Whereas, 30% of analyzed samples had levels of Cd above allowable levels, and were statistically correlated with Ca, and Zn essential minerals. Similarly 62% of the samples had levels of As above allowable limits and As levels were associated with Fe and Mn essential minerals. Conclusion Dietary supplements consumed as essential nutrients for their Ca, Zn, Fe and Mn content should be monitored for toxic metal levels due to their natural geochemical association with these essential metals to provide citizens the safe allowable amounts. PMID:23331553

In utero exposure to low dose arsenic via drinking water impairs early life lung mechanics in mice

PubMed Central

2013-01-01

Background Exposure to arsenic via drinking water is a significant environmental issue affecting millions of people around the world. Exposure to arsenic during foetal development has been shown to impair somatic growth and increase the risk of developing chronic respiratory diseases. The aim of this study was to determine if in utero exposure to low dose arsenic via drinking water is capable of altering lung growth and postnatal lung mechanics. Methods Pregnant C57BL/6 mice were given drinking water containing 0, 10 (current World Health Organisation (WHO) maximum contaminant level) or 100μg/L arsenic from gestational day 8 to birth. Birth outcomes and somatic growth were monitored. Plethysmography and the forced oscillation technique were used to collect measurements of lung volume, lung mechanics, pressure-volume curves and the volume dependence of lung mechanics in male and female offspring at two, four, six and eight weeks of age. Results In utero exposure to low dose arsenic via drinking water resulted in low birth weight and impaired parenchymal lung mechanics during infancy. Male offspring were more susceptible to the effects of arsenic on growth and lung mechanics than females. All alterations to lung mechanics following in utero arsenic exposure were recovered by adulthood. Conclusions Exposure to arsenic at the current WHO maximum contaminant level in utero impaired somatic growth and the development of the lungs resulting in alterations to lung mechanics during infancy. Deficits in growth and lung development in early life may contribute to the increased susceptibility of developing chronic respiratory disease in arsenic exposed human populations. PMID:23419080

Human Health Effects of Biphenyl: Key Findings and Scientific Issues

PubMed Central

Li, Zheng; Hogan, Karen A.; Cai, Christine; Rieth, Susan

2015-01-01

Background: In support of the Integrated Risk Information System (IRIS), the U.S. Environmental Protection Agency (EPA) has evaluated the human health hazards of biphenyl exposure. Objectives: We review key findings and scientific issues regarding expected human health effects of biphenyl. Methods: Scientific literature from 1926 through September 2012 was critically evaluated to identify potential human health hazards associated with biphenyl exposure. Key issues related to the carcinogenicity and noncancer health hazards of biphenyl were examined based on evidence from experimental animal bioassays and mechanistic studies. Discussion: Systematic consideration of experimental animal studies of oral biphenyl exposure took into account the variety of study designs (e.g., study sizes, exposure levels, and exposure durations) to reconcile differing reported results. The available mechanistic and toxicokinetic evidence supports the hypothesis that male rat urinary bladder tumors arise through urinary bladder calculi formation but is insufficient to hypothesize a mode of action for liver tumors in female mice. Biphenyl and its metabolites may induce genetic damage, but a role for genotoxicity in biphenyl-induced carcinogenicity has not been established. Conclusions: The available health effects data for biphenyl provides suggestive evidence for carcinogenicity in humans, based on increased incidences of male rat urinary bladder tumors at high exposure levels and on female mouse liver tumors. Kidney toxicity is also a potential human health hazard of biphenyl exposure. Citation: Li Z, Hogan KA, Cai C, Rieth S. 2016. Human health effects of biphenyl: key findings and scientific issues. Environ Health Perspect 124:703–712; http://dx.doi.org/10.1289/ehp.1509730 PMID:26529796

High risks of lung disease associated with early-life and moderate lifetime arsenic exposure in northern Chile

PubMed Central

Steinmaus, Craig; Ferreccio, Catterina; Acevedo, Johanna; Balmes, John R; Liaw, Jane; Troncoso, Patricia; Dauphiné, David C; Nardone, Anthony; Smith, Allan H

2016-01-01

Background Arsenic in drinking water has been associated with increases in lung disease, but information on the long-term impacts of early-life exposure or moderate exposure levels are limited. Methods We investigated pulmonary disease and lung function in 795 subjects from three socio-demographically similar areas in northern Chile: Antofagasta, which had a well-described period of high arsenic water concentrations (860 μg/L) from 1958–1970; Iquique, which had long-term arsenic water concentrations near 60 μg/L; and Arica, with long-term water concentrations ≤10 μg/L. Results Compared to adults never exposed >10 μg/L, adults born in Antofagasta during the high exposure period had elevated odds ratios (OR) of respiratory symptoms (e.g., OR for shortness of breath = 5.56, 90% confidence interval (CI): 2.68–11.5), and decreases in pulmonary function (e.g., 224 ml decrease in forced vital capacity in nonsmokers, 90% CI: 97–351 ml). Subjects with long-term exposure to arsenic water concentrations near 60 μg/L also had increases in some pulmonary symptoms and reduced lung function. Conclusions Overall, these findings provide new evidence that in utero or childhood arsenic exposure is associated with non-malignant pulmonary disease in adults. They also provide preliminary new evidence that long-term exposures to moderate levels of arsenic may be associated with lung toxicity, although the magnitude of these latter findings were greater than expected and should be confirmed. PMID:27725189

A Biomonitoring Framework to Support Exposure and Risk Assessments

EPA Science Inventory

Background - Biomonitoring is used in exposure and risk assessments to reduce uncertainties along the source-to-outcome continuum. Specifically, biomarkers can help identify exposure sources, routes, and distributions, and reflect kinetic and dynamic processes following exposure ...

Quantitative assessment of airborne exposures generated during common cleaning tasks: a pilot study

PubMed Central

2010-01-01

Background A growing body of epidemiologic evidence suggests an association between exposure to cleaning products with asthma and other respiratory disorders. Thus far, these studies have conducted only limited quantitative exposure assessments. Exposures from cleaning products are difficult to measure because they are complex mixtures of chemicals with a range of physicochemical properties, thus requiring multiple measurement techniques. We conducted a pilot exposure assessment study to identify methods for assessing short term, task-based airborne exposures and to quantitatively evaluate airborne exposures associated with cleaning tasks simulated under controlled work environment conditions. Methods Sink, mirror, and toilet bowl cleaning tasks were simulated in a large ventilated bathroom and a small unventilated bathroom using a general purpose, a glass, and a bathroom cleaner. All tasks were performed for 10 minutes. Airborne total volatile organic compounds (TVOC) generated during the tasks were measured using a direct reading instrument (DRI) with a photo ionization detector. Volatile organic ingredients of the cleaning mixtures were assessed utilizing an integrated sampling and analytic method, EPA TO-17. Ammonia air concentrations were also measured with an electrochemical sensor embedded in the DRI. Results Average TVOC concentrations calculated for 10 minute tasks ranged 0.02 - 6.49 ppm and the highest peak concentrations observed ranged 0.14-11 ppm. TVOC time concentration profiles indicated that exposures above background level remained present for about 20 minutes after cessation of the tasks. Among several targeted VOC compounds from cleaning mixtures, only 2-BE was detectable with the EPA method. The ten minute average 2- BE concentrations ranged 0.30 -21 ppm between tasks. The DRI underestimated 2-BE exposures compared to the results from the integrated method. The highest concentration of ammonia of 2.8 ppm occurred during mirror cleaning. Conclusions Our results indicate that airborne exposures from short-term cleaning tasks can remain in the air even after tasks' cessation, suggesting potential exposures to anyone entering the room shortly after cleaning. Additionally, 2-BE concentrations from cleaning could approach occupational exposure limits and warrant further investigation. Measurement methods applied in this study can be useful for workplace assessment of airborne exposures during cleaning, if the limitations identified here are addressed. PMID:21118559

Measured Occupational Solar UVR Exposures of Lifeguards in Pool Settings

PubMed Central

Gies, Peter; Glanz, Karen; O’Riordan, David; Elliott, Tom; Nehl, Eric

2013-01-01

Background The aim of this study was to measure ultraviolet radiation (UVR) exposures of lifeguards in pool settings and evaluate their personal UVR protective practices. Methods Lifeguards (n = 168) wore UVR sensitive polysulfone (PS) film badges in wrist bracelets on 2 days and completed a survey and diary covering sun protection use. Analyses were used to describe sun exposure and sun protection practices, to compare UVR exposure across locations, and to compare findings with recommended threshold limits for occupational exposure. Results The measured UVR exposures varied with location, ranging from high median UVR exposures of 6.2 standard erythemal doses (SEDs) to the lowest median of 1.7 SEDs. More than 74% of the lifeguards’ PS badges showed UVR above recommended threshold limits for occupational exposure. Thirty-nine percent received more than four times the limit and 65% of cases were sufficient to induce sunburn. The most common protective behaviors were wearing sunglasses and using sunscreen, but sun protection was often inadequate. Conclusions At-risk individuals were exposed to high levels of UVR in excess of occupational limits and though appropriate types of sun protection were used, it was not used consistently and more than 50% of lifeguards reported being sunburnt at least twice during the previous year. PMID:19572325

Pre-Clinical Medical Students' Exposure to and Attitudes Toward Pharmaceutical Industry Marketing.

PubMed

Fein, Eric H; Vermillion, Michelle L; Uijtdehaage, Sebastian H J

2007-12-01

Background - Recent studies have examined the exposures and attitudes of physicians and third- and fourth-year medical students toward pharmaceutical industry marketing, but fewer studies have addressed these topics among pre-clinical medical students. Thus, the purpose of this study was to assess pre-clinical students' level of exposure to the pharmaceutical industry and their attitudes toward marketing. Method - First and second-year medical students at UCLA completed a 40-item survey based on previous studies. Results - Over three quarters of pre-clinical students (78.5% or 226 of 288) responded to the survey. Exposure to pharmaceutical industry marketing started very early in medical school. Most second-year students (77%) had received gifts including drug samples after three semesters. Most felt that this would not affect their future prescribing behavior. Conclusions - These findings and findings from related studies, coupled with the students' desire to learn more about the issue, suggest that an early educational intervention addressing this topic may be warranted in American medical schools.

High altitude simulation, substance P and airway rapidly adapting receptor activity in rabbits.

PubMed

Bhagat, R; Yasir, A; Vashisht, A; Kulshreshtha, R; Singh, S B; Ravi, K

2011-09-15

To investigate whether there is a change in airway rapidly adapting receptor (RAR) activity during high altitude exposure, rabbits were placed in a high altitude simulation chamber (barometric pressure, 429 mm Hg). With 12 h exposure, when there was pulmonary congestion, an increase in basal RAR activity was observed. With 36 h exposure, when there was alveolar edema, there was a further increase in basal RAR activity. In these backgrounds, there was an increase in the sensitivity of the RARs to substance P (SP). To assess whether there was an increase in lung SP level, neutral endopeptidase activity was determined which showed a decrease in low barometric pressure exposed groups. It is concluded that along with the SP released, pulmonary congestion and edema produced, respectively by different durations of low barometric pressure exposure cause a progressive increase in RAR activity which may account for the respiratory symptoms reported in climbers who are unacclimatized. Copyright © 2011 Elsevier B.V. All rights reserved.

Two-sample discrimination of Poisson means

NASA Technical Reports Server (NTRS)

Lampton, M.

1994-01-01

This paper presents a statistical test for detecting significant differences between two random count accumulations. The null hypothesis is that the two samples share a common random arrival process with a mean count proportional to each sample's exposure. The model represents the partition of N total events into two counts, A and B, as a sequence of N independent Bernoulli trials whose partition fraction, f, is determined by the ratio of the exposures of A and B. The detection of a significant difference is claimed when the background (null) hypothesis is rejected, which occurs when the observed sample falls in a critical region of (A, B) space. The critical region depends on f and the desired significance level, alpha. The model correctly takes into account the fluctuations in both the signals and the background data, including the important case of small numbers of counts in the signal, the background, or both. The significance can be exactly determined from the cumulative binomial distribution, which in turn can be inverted to determine the critical A(B) or B(A) contour. This paper gives efficient implementations of these tests, based on lookup tables. Applications include the detection of clustering of astronomical objects, the detection of faint emission or absorption lines in photon-limited spectroscopy, the detection of faint emitters or absorbers in photon-limited imaging, and dosimetry.

Antenatal Dexamethasone Exposure in Preterm Infants Is Associated with Allergic Diseases and the Mental Development Index in Children.

PubMed

Tseng, Wan-Ning; Chen, Chih-Cheng; Yu, Hong-Ren; Huang, Li-Tung; Kuo, Ho-Chang

2016-12-03

Background: Antenatal steroid administration may benefit fetal lung maturity in preterm infants. Although some studies have shown that this treatment may increase asthma in childhood, the correlation between antenatal dexamethasone exposure and allergic diseases remains unclear. The purpose of this study is to investigate the association between antenatal dexamethasone and T cell expression in childhood allergic diseases. Methods: We recruited a cohort of preterm infants born at Kaohsiung Chang Gung Memorial Hospital between 2007 and 2010 with a gestational age of less than 35 weeks and body weight at birth of less than 1500 g. The status of antenatal exposure to steroids and allergic diseases were surveyed using a modified ISAAC questionnaire for subjects aged 2-5 years old. We analyzed Th1/Th2/Th17 expression of mRNA, cytokines (using the Magpix ® my-system), and mental development index (MDI). Results: Among the 40 patients that were followed, the data showed that the antenatal dexamethasone exposure group ( N = 24) had a significantly higher incidence of allergic diseases (75.0% vs. 18.8%, p < 0.0001) when compared to the non-dexamethasone exposure group ( N = 16), especially with regard to asthma (41.7% vs. 0.0%, p = 0.003) and allergic rhinitis (58.3% vs. 18.8%, p = 0.013), but not atopic dermatitis. No statistical difference was observed in the mRNA expression levels of total white blood cell count between the dexamethasone exposure and non-exposure groups ( p > 0.05). However, the asthma group had higher IL-5 levels ( p = 0.009), and the MDI was shown to be significantly higher in the dexamethasone exposure group (90.38 ± 3.31 vs. 79.94 ± 3.58, p = 0.043) while no significant difference was found between the PDI of the two groups. Conclusions: Exposure to antenatal dexamethasone in preterm infants will increase their susceptibility to allergic diseases, particularly asthma and allergic rhinitis. Preterm infants' exposure to antenatal dexamethasone also results in higher MDI scores. Such increases in allergic diseases may be related to increased IL-5 and IL-10 levels.

E-Waste Informal Recycling: An Emerging Source of Lead Exposure in South America

PubMed Central

Pascale, Antonio; Sosa, Adriana; Bares, Cristina; Battocletti, Alejandra; Moll, María José; Pose, Darío; Laborde, Amalia; González, Hugo; Feola, Gabriella

2016-01-01

BACKGROUND Primitive electronic waste (e-waste) recycling creates exposures to several hazardous substances including lead. In Uruguay, primitive recycling procedures are a significant source of lead exposure. OBJECTIVES The aim of this study was to examine lead exposure in blood lead levels (BLLs) in low-income children exposed to lead through burning cables. METHODS A sample of children and adolescents exposed to lead through burning cable activities were assessed at the Department of Toxicology in Montevideo, Uruguay, between 2010 and 2014. Soil lead levels of residences were taken shortly after their assessment. FINDINGS The final sample included 69 children and adolescents (mean age 7.89 years). More than 66% of participants had an additional source of lead exposure—manual gathering of metals—and <5% were exposed to lead through landfills or paint. Average BLLs at first consultation were 9.19 ug/dL and lower at the second measurement (5.86 μg/dL). Data from soil lead levels ranged from 650 to 19,000 mg of lead/kg of soil. The interventions conducted after the assessment included family education in the clinic and at home, indoor and outdoor remediation. We found a decrease in BLLs of 6.96 μg/dL. Older children had lower BLLs (r = −0.24; P =0.05). Statistical analyses also showed that children living in areas with higher soil lead levels had significantly higher BLLs (r = 0.50; P < 0.01). Additionally, we found greater BLLs from burning cable activities when children had been exposed to lead-based paint (r = 0.23; P < 0.1). CONCLUSION Among children exposed to e-waste recycling, the most common additional source of lead exposure was the manual gathering of metals. The average BLL among children and adolescents in this study is higher than the BLLs currently suggested in medical intervention. Future research should focus on exploring effective interventions to reduce lead exposure among this vulnerable group. PMID:27325077

A Comparison of Particulate Matter from Biomass-Burning Rural and Non-Biomass-Burning Urban Households in Northeastern China

PubMed Central

Jiang, Ruoting; Bell, Michelle L.

2008-01-01

Background Biomass fuel is the primary source of domestic fuel in much of rural China. Previous studies have not characterized particle exposure through time–activity diaries or personal monitoring in mainland China. Objectives In this study we characterized indoor and personal particle exposure in six households in northeastern China (three urban, three rural) and explored differences by location, cooking status, activity, and fuel type. Rural homes used biomass. Urban homes used a combination of electricity and natural gas. Methods Stationary monitors measured hourly indoor particulate matter (PM) with an aerodynamic diameter ≤ 10 μm (PM10) for rural and urban kitchens, urban sitting rooms, and outdoors. Personal monitors for PM with an aerodynamic diameter ≤ 2.5 μm (PM2.5) were employed for 10 participants. Time–activity patterns in 30-min intervals were recorded by researchers for each participant. Results Stationary monitoring results indicate that rural kitchen PM10 levels are three times higher than those in urban kitchens during cooking. PM10 was 6.1 times higher during cooking periods than during noncooking periods for rural kitchens. Personal PM2.5 levels for rural cooks were 2.8–3.6 times higher than for all other participant categories. The highest PM2.5 exposures occurred during cooking periods for urban and rural cooks. However, rural cooks had 5.4 times higher PM2.5 levels during cooking than did urban cooks. Rural cooks spent 2.5 times more hours per day cooking than did their urban counterparts. Conclusions These findings indicate that biomass burning for cooking contributes substantially to indoor particulate levels and that this exposure is particularly elevated for cooks. Second-by-second personal PM2.5 exposures revealed differences in exposures by population group and strong temporal heterogeneity that would be obscured by aggregate metrics. PMID:18629313

Effects of long-term low-level radiation exposure after the Chernobyl catastrophe on immunoglobulins in children residing in contaminated areas: prospective and cross-sectional studies

PubMed Central

2014-01-01

Background After the Chernobyl nuclear incident in 1986, children in the Narodichesky region, located 80 km west of the Chernobyl Power Plant, were exposed to 137Cesium (137Cs). Little is known about the effects of chronic low-level radiation on humoral immune responses in children residing in contaminated areas. Methods In four different approaches we investigated the effect of residential 137Cs exposure on immunoglobulins A, G, M, and specific immunoglobulin E in children. In a dynamic cohort (1993–1998) we included 617 children providing 2,407 repeated measurements; 421 and 523 children in two cross-sectional samples (1997–1998 and 2008–2010, respectively); and 25 participants in a small longitudinal cohort (1997–2010). All medical exams, blood collections, and analyses were conducted by the same team. We used mixed linear models to analyze repeated measurements in cohorts and general linear regression models for cross-sectional studies. Results Residential soil contamination in 2008 was highly correlated with the individual body burden of 137Cs. Serum IgG and IgM concentrations increased between 1993 and 1998. Children with higher 137Cs soil exposure had lower serum IgG levels, which, however, increased in the small cohort assessed between 1997 and 2010. Children within the fourth quintile of 137Cs soil exposure (266–310 kBq/m2) had higher IgM serum concentrations between 1993 and 1998 but these declined between 1997 and 2010. IgA remained stable with median 137Cs exposures related to higher IgA levels, which was corroborated in the cross-sectional study of 2008–2010. Specific IgE against indoor allergens was detected less often in children with higher 137Cs exposure. Conclusions Our findings show radiation-related alterations of immunoglobulins which by themselves do not constitute adverse health effects. Further investigations are necessary to understand how these changes affect health status. PMID:24886042

Menstrual function among women exposed to polybrominated biphenyls: A follow-up prevalence study

PubMed Central

Davis, Stephanie I; Blanck, Heidi Michels; Hertzberg, Vicki S; Tolbert, Paige E; Rubin, Carol; Cameron, Lorraine L; Henderson, Alden K; Marcus, Michele

2005-01-01

Background Alteration in menstrual cycle function is suggested among rhesus monkeys and humans exposed to polybrominated biphenyls (PBBs) and structurally similar polychlorinated biphenyls (PCBs). The feedback system for menstrual cycle function potentially allows multiple pathways for disruption directly through the hypothalamic-pituitary-ovarian axis and indirectly through alternative neuroendocrine axes. Methods The Michigan Female Health Study was conducted during 1997–1998 among women in a cohort exposed to PBBs in 1973. This study included 337 women with self-reported menstrual cycles of 20–35 days (age range: 24–56 years). Current PBB levels were estimated by exponential decay modeling of serum PBB levels collected from 1976–1987 during enrollment in the Michigan PBB cohort. Linear regression models for menstrual cycle length and the logarithm of bleed length used estimated current PBB exposure or enrollment PBB exposure categorized in tertiles, and for the upper decile. All models were adjusted for serum PCB levels, age, body mass index, history of at least 10% weight loss in the past year, physical activity, smoking, education, and household income. Results Higher levels of physical activity were associated with shorter bleed length, and increasing age was associated with shorter cycle length. Although no overall association was found between PBB exposure and menstrual cycle characteristics, a significant interaction between PBB exposures with past year weight loss was found. Longer bleed length and shorter cycle length were associated with higher PBB exposure among women with past year weight loss. Conclusion This study suggests that PBB exposure may impact ovarian function as indicated by menstrual cycle length and bleed length. However, these associations were found among the small number of women with recent weight loss suggesting either a chance finding or that mobilization of PBBs from lipid stores may be important. These results should be replicated with larger numbers of women exposed to similar lipophilic compounds. PMID:16091135

Benzene and naphthalene in air and breath as indicators of exposure to jet fuel

PubMed Central

Egeghy, P; Hauf-Cabalo, L; Gibson, R; Rappaport, S

2003-01-01

Aims: To estimate exposures to benzene and naphthalene among military personnel working with jet fuel (JP-8) and to determine whether naphthalene might serve as a surrogate for JP-8 in studies of health effects. Methods: Benzene and naphthalene were measured in air and breath of 326 personnel in the US Air Force, who had been assigned a priori into low, moderate, and high exposure categories for JP-8. Results: Median air concentrations for persons in the low, moderate, and high exposure categories were 3.1, 7.4, and 252 µg benzene/m3 air, 4.6, 9.0, and 11.4 µg benzene/m3 breath, 1.9, 10.3, and 485 µg naphthalene/m3 air, and 0.73, 0.93, and 1.83 µg naphthalene/m3 breath, respectively. In the moderate and high exposure categories, 5% and 15% of the benzene air concentrations, respectively, were above the 2002 threshold limit value (TLV) of 1.6 mg/m3. Multiple regression analyses of air and breath levels revealed prominent background sources of benzene exposure, including cigarette smoke. However, naphthalene exposure was not unduly influenced by sources other than JP-8. Among heavily exposed workers, dermal contact with JP-8 contributed to air and breath concentrations along with several physical and environmental factors. Conclusions: Personnel having regular contact with JP-8 are occasionally exposed to benzene at levels above the current TLV. Among heavily exposed workers, uptake of JP-8 components occurs via both inhalation and dermal contact. Naphthalene in air and breath can serve as useful measures of exposure to JP-8 and uptake of fuel components in the body. PMID:14634191

Impact of light exposure on thyroid-stimulating hormone results using the Siemens Advia Centaur TSH-3Ultra assay.

PubMed

Armer, Jane; Giles, Diane; Lancaster, Ian; Brownbill, Kathryn

2017-09-01

Background Thyroid-stimulating hormone (TSH) is used as the first-line test of thyroid function. Siemens Healthcare Diagnostics recommend that Siemens Centaur reagents must be protected from light in the assay information and on reagent packaging. We have compared the effect of light exposure on results using Siemens TSH-3Ultra and follicle-stimulating hormone reagents. The thyroid-stimulating hormone reagent includes fluoroscein thiocyanate whereas the follicle-stimulating hormone reagent does not. Methods Three levels of quality controls were analysed using SiemensTSH-3Ultra and follicle-stimulating hormone reagent packs that had been kept protected from light or exposed to light at 6-h intervals for 48 h and then at 96 h. Results Thyroid-stimulating hormone results were significantly lower after exposure of TSH-3Ultra reagent packs to light. Results were >15% lower at all three levels of quality control following 18 h of light exposure and continued to decrease until 96 h. There was no significant difference in follicle-stimulating hormone results whether reagents had been exposed to or protected from light. Conclusions Thyroid-stimulating hormone results but not follicle-stimulating hormone results are lowered after exposure of reagent packs to light. Laboratories must ensure that TSH-3Ultra reagents are not exposed to light and analyse quality control samples on every reagent pack to check that there has not been light exposure prior to delivery. The labelling on TSH-3Ultra reagent packs should reflect the significant effect of light exposure compared with the follicle-stimulating hormone reagent. We propose that the effect of light exposure on binding of fluoroscein thiocyanate to the solid phase antibody causes the falsely low results.

Developmental exposure to acetaminophen does not induce hyperactivity in zebrafish larvae.

PubMed

Reuter, Isabel; Knaup, Sabine; Romanos, Marcel; Lesch, Klaus-Peter; Drepper, Carsten; Lillesaar, Christina

2016-08-01

First line pain relief medication during pregnancy relies nearly entirely on the over-the-counter analgesic acetaminophen, which is generally considered safe to use during gestation. However, recent epidemiological studies suggest a risk of developing attention-deficit/hyperactivity disorder (ADHD)-like symptoms in children if mothers use acetaminophen during pregnancy. Currently, there are no experimental proofs that prenatal acetaminophen exposure causes developmental brain alterations of progeny. Exposure to high acetaminophen concentrations causes liver toxicity, which is well investigated in different model organisms. However, sub-liver-toxic concentrations have not been experimentally investigated with respect to ADHD endophenotypes such as hyperactivity. We used zebrafish to investigate the potential impact of acetaminophen exposure on locomotor activity levels, and compared it to the established zebrafish Latrophilin 3 (Lphn3) ADHD-model. We determined the sub-liver-toxic concentration of acetaminophen in zebrafish larvae and treated wild-type and lphn3.1 knockdown larvae with increasing concentrations of acetaminophen. We were able to confirm that lphn3.1 knockdown alone causes hyperactivity, strengthening the implication of Lphn3 dysfunction as an ADHD risk factor. Neither acute nor chronic exposure to acetaminophen at sub-liver-toxic concentrations in wild-type or lphn3.1 knock-downs increases locomotor activity levels. Together our findings show that embryonic to larval exposure to acetaminophen does not cause hyperactivity in zebrafish larvae. Furthermore, there are no additive and/or synergistic effects of acetaminophen exposure in a susceptible background induced by knock-down of lphn3.1. Our experimental study suggests that there is, at least in zebrafish larvae, no direct link between embryonic acetaminophen exposure and hyperactivity. Further work is necessary to clarify this issue in humans.

A STUDY OF THE MASS BALANCE OF DIOXINS AND FURANS IN LACTATING COWS IN BACKGROUND CONDITIONS

EPA Science Inventory

Consumption of animal fats account for as much as 95% of the human background exposure to compounds with dioxin-like activity. Although it is generally believed that most domestic meat and dairy animals receive most of their exposure from their feed, there is limited data availa...

Partner smoking and maternal cotinine during pregnancy: Implications for negative control methods☆

PubMed Central

Taylor, Amy E.; Davey Smith, George; Bares, Cristina B.; Edwards, Alexis C.; Munafò, Marcus R.

2014-01-01

Background Comparison of the associations of maternal and mother's partner smoking with offspring outcomes is, in theory, a useful method for assessing whether there may be an intrauterine effect of tobacco exposure on these outcomes. However, this approach assumes that the effects of passive smoking from exposure to partner smoking during pregnancy are minimal. We evaluated this assumption using a biochemical measure of tobacco exposure in pregnant women. Methods Cotinine levels taken during the first trimester of pregnancy were measured in a sample of 3928 women from the Avon Longitudinal Study of Parents and Children. Median cotinine values were compared across categories of smoking heaviness (cigarettes per day) of the women during the first trimester and in non-smoking women by the smoking heaviness of their partner. Results Cotinine levels were substantially higher in women who smoked compared to non-smokers (range of medians across smoking heaviness categories: 900–5362 ng/ml versus 20 ng/ml, interquartile range (IQR) (0–63) for non-smokers). In contrast, cotinine levels in non-smoking women were only very weakly related to partner smoking status (range of medians in women with smoking partners: 34–69 ng/ml versus 12 ng/ml, IQR (0–48) in women with non-smoking partners). Conclusions Levels of tobacco exposure from partner smoking, as assessed by cotinine, were low in non-smoking pregnant women. This suggests that using mother's partner's smoking as a negative control for investigating intrauterine effects is valid. PMID:24726428

Personal exposure to ultrafine particles from PVC welding and concrete work during tunnel rehabilitation.

PubMed

Jørgensen, Rikke Bramming; Buhagen, Morten; Føreland, Solveig

2016-07-01

To investigate the exposure to number concentration of ultrafine particles and the size distribution in the breathing zone of workers during rehabilitation of a subsea tunnel. Personal exposure was measured using a TSI 3091 Fast Mobility Particle Sizer (FMPS), measuring the number concentration of submicrometre particles (including ultrafine particles) and the particle size distribution in the size range 5.6-560 nm. The measurements were performed in the breathing zone of the operators by the use of a conductive silicone tubing. Working tasks studied were operation of the slipforming machine, operations related to finishing the verge, and welding the PVC membrane. In addition, background levels were measured. Arithmetic mean values of ultrafine particles were in the range 6.26×10(5)-3.34×10(6). Vertical PVC welding gave the highest exposure. Horizontal welding was the work task with the highest maximum peak exposure, 8.1×10(7) particles/cm(3). Background concentrations of 4.0×10(4)-3.1×10(5) were found in the tunnel. The mobility diameter at peak particle concentration varied between 10.8 nm during horizontal PVC welding and during breaks and 60.4 nm while finishing the verge. PVC welding in a vertical position resulted in very high exposure of the worker to ultrafine particles compared to other types of work tasks. In evaluations of worker exposure to ultrafine particles, it seems important to distinguish between personal samples taken in the breathing zone of the worker and more stationary work area measurements. There is a need for a portable particle-sizing instrument for measurements of ultrafine particles in working environments. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Air pollution as a risk factor in health impact assessments of a travel mode shift towards cycling

PubMed Central

Raza, Wasif; Forsberg, Bertil; Johansson, Christer; Sommar, Johan Nilsson

2018-01-01

ABSTRACT Background: Promotion of active commuting provides substantial health and environmental benefits by influencing air pollution, physical activity, accidents, and noise. However, studies evaluating intervention and policies on a mode shift from motorized transport to cycling have estimated health impacts with varying validity and precision. Objective: To review and discuss the estimation of air pollution exposure and its impacts in health impact assessment studies of a shift in transport from cars to bicycles in order to guide future assessments. Methods: A systematic database search of PubMed was done primarily for articles published from January 2000 to May 2016 according to PRISMA guidelines. Results: We identified 18 studies of health impact assessment of change in transport mode. Most studies investigated future hypothetical scenarios of increased cycling. The impact on the general population was estimated using a comparative risk assessment approach in the majority of these studies, whereas some used previously published cost estimates. Air pollution exposure during cycling was estimated based on the ventilation rate, the pollutant concentration, and the trip duration. Most studies employed exposure-response functions from studies comparing background levels of fine particles between cities to estimate the health impacts of local traffic emissions. The effect of air pollution associated with increased cycling contributed small health benefits for the general population, and also only slightly increased risks associated with fine particle exposure among those who shifted to cycling. However, studies calculating health impacts based on exposure-response functions for ozone, black carbon or nitrogen oxides found larger effects attributed to changes in air pollution exposure. Conclusion: A large discrepancy between studies was observed due to different health impact assessment approaches, different assumptions for calculation of inhaled dose and different selection of dose-response functions. This kind of assessments would improve from more holistic approaches using more specific exposure-response functions. PMID:29400262

Assessment of the influence of whole body vibration on Cochlear function

PubMed Central

2012-01-01

Background Whole body vibration (WBV) is a potentially harmful consequence resulting from the dissipation of energy by industrial machineries. The result of WBV exposure on the auditory system remains unknown. The objective of the present research was to evaluate the influence of WBV on cochlear function, in particular outer hair cell function. It is hypothesized that WBV impairs cochlear function resulting in decreased Distortion Product Otoacoustic Emission (DPOAE) levels (Ldp) in rabbits subjected to WBV. Methods Twelve rabbits were equally divided into vibration and control groups. Animals in vibration group were exposed to 1.0 ms-2 r.m.s vertical WBV at 4–8 Hz for 8 h/day during 5 consecutive days. Outer hair cell function was assessed by comparing repeated-measurements of DPOAE levels (Ldp) across a range of f2 frequencies in rabbits both exposed and unexposed to WBV. DPOAE level shifts (LSdp) were compared across ears, frequencies, groups, and times. Results No differences were seen over time in DPOAE levels in the non-exposed rabbits (p = 0.082). Post-exposure Ldp in rabbits exposed to WBV were significantly increased at all test frequencies in both ears compared to baseline measures (p = 0.021). The greatest increase in Ldp following exposure was seen at 5888.5 Hz (mean shift = 13.25 dB). Post-exposure Ldp in rabbits exposed to WBV were not significantly different between the right and left ears (p = 0.083). Conclusion WBV impairs cochlear function resulting in increased DPOAE responses in rabbits exposed to WBV. DPOAE level shifts occurred over a wide range of frequencies following prolonged WBV in rabbits. PMID:22720724

Elevated maternal cortisol levels during pregnancy are associated with reduced childhood IQ

PubMed Central

LeWinn, Kaja Z; Stroud, Laura R; Molnar, Beth E; Ware, James H; Koenen, Karestan C; Buka, Stephen L

2009-01-01

Background In animal models, there is evidence to suggest a causal link between maternal cortisol levels during pregnancy and offspring outcomes; however, evidence for this relationship in humans is inconclusive. We address important confounders of this association by estimating the relationship between maternal cortisol levels in late pregnancy and childhood IQ in a birth cohort and in a subsample of siblings. Methods This study included 832 children who were members of the Collaborative Perinatal Project. Maternal serum collected between 1959 and 1966 during the third trimester of pregnancy was analysed for free cortisol. We investigated the relationship between maternal cortisol in quintiles and full, verbal and performance scale scores on the Wechsler Intelligence Scale for Children at age 7 years, adjusting for prenatal and family characteristics. We repeated this analysis among 74 discordant sibling pairs using a fixed effects approach, which adjusts for shared family characteristics. Results Maternal cortisol levels were negatively related to full-scale IQ, an effect driven by verbal IQ scores. Compared with those in the lowest quintile of cortisol exposure, the verbal IQ of children in the highest quintile of exposure was 3.83 points lower [95% confidence interval (CI): −6.44 to −1.22]. Within sibling pairs, being in the highest quintile of exposure was associated with verbal IQ scores 5.5 points lower (95% CI: −11.24 to 0.31) compared with the other quintiles. Conclusion These findings are consistent with prior human and animal studies, and suggest that exposure to high levels of maternal cortisol during pregnancy may be negatively related to offspring cognitive skills independently of family attributes that characterize the postnatal environment. PMID:19423658

Betel quid chewing as a source of manganese exposure: total daily intake of manganese in a Bangladeshi population

PubMed Central

2011-01-01

Background A relationship between betel quid chewing in Bangladeshi populations and the development of skin lesions and tremor has been previously reported, for people exposed to high levels of arsenic (As) through drinking contaminated groundwater. Exposure to manganese (Mn) is also known to induce neurotoxicity and levels of Mn in Bangladeshi groundwater are also high. The present study evaluates betel quid chewing as an overlooked source of Mn exposure in a Bangladeshi population. Methods Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine (1) urinary Mn levels for 15 chewers and 22 non-chewers from the ethnic Bangladeshi community in the United Kingdom, and (2) Mn levels in betel quids, its individual components and other Bangladeshi foods. Results Betel quid chewers displayed a significantly higher (P = 0.009) mean Mn concentration in urine (1.93 μg L-1) compared to non-chewers (0.62 μg L-1). High levels of Mn were detected in Piper betel leaves with an overall average of 135 mg kg-1 (range 26 -518 mg kg-1). The mean concentration of Mn in betel quid was 41 mg kg-1 (SD 27) and the daily intake of Mn in the Bangladeshi population was estimated to be 20.3 mg/day. Chewing six betel quids could contribute up to 18% of the maximum recommended daily intake of Mn. Conclusion We have demonstrated that Mn in betel quids is an overlooked source of exposure to Mn in humans. Chewers display a 3.1 fold increased urinary Mn concentration compared to non-chewers. The practice of betel quid chewing contributes a high proportion of the maximum recommended daily intake of Mn, which could make chewers in Bangladesh more vulnerable to Mn neurotoxicity. PMID:21299859

Safety assessment of the use of Bacillus-based cleaning products.

PubMed

Berg, Ninna W; Evans, Matthew R; Sedivy, John; Testman, Robert; Acedo, Kimon; Paone, Domenic; Long, David; Osimitz, Thomas G

2018-06-01

Non-pathogenic Bacillus species used in cleaning products produce the appropriate enzymes to degrade stains and soils. However, there is little scientific data regarding the human exposure by inhalation of Bacillus spores during or after use of microbial-based cleaning products. Herein, air samples were collected at various locations in a ventilated, carpeted, residential room to determine the air concentration of viable bacteria and spores during and after the application of microbial-based carpet cleaning products containing Bacillus spores. The influence of human activities and vacuuming was investigated. Bioaerosol levels associated with use and post-application activities of whole room carpet treatments were elevated during post-application activity, but quickly returned to the indoor background range. Use of trigger spray spot applications generated aerosolized spores in the immediate vicinity, however, their use pattern and the generation of mostly non-respirable particles suggest minimal risks for pulmonary exposure from their use. The aerosol counts associated with use of these microbial-based cleaners were below the recommendation for safe exposure levels to non-pathogenic and non-toxigenic microorganisms except during application of the spot cleaner. The data presented suggest that carpet cleaning products, containing non-pathogenic Bacillus spores present a low potential for inhalation exposure and consequently minimal risk of adverse effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effect of Low-Dose Ionizing Radiation on Stem Cell Biology: A Contribution to Radiation Risk.

PubMed

Squillaro, Tiziana; Galano, Giovanni; De Rosa, Roberto; Peluso, Gianfranco; Galderisi, Umberto

2018-04-17

Exposure to high levels of ionizing radiation (IR) (>0.5Gy), negatively affect health. but, less is known about the effects of low dose IR (LDIR) but recent, evidence suggests that it may have profound effects on cellular functions. We are commonly exposed to LDIR over natural background levels from numerous sources: people may be exposed to low dose IR for medical diagnosis and therapy, air travel, illegal IR waste dumpsites or by occupational exposures in the nuclear and medical sectors. Stem cells reside for long periods of time in our bodies, and this increases the possibility that they may be accumulate genotoxic damage derived from extrinsic LDIR or intrinsic sources (such as DNA replication). In this review we provide an overview of LDIR effects on biology of stem cell compartments. The principal findings and issues reported in the scientific literature are discussed in order to present the current understanding of the LDIR exposure risk, and assess whether it may impact human health. We first consider the general biological consequences of LDIR exposure. Following this, we discuss the effects of LDIR on stem cells as discovered through in vitro and in vivo studies. This article is protected by copyright. All rights reserved. © 2018 AlphaMed Press.

Spatio-temporal variation of urban ultrafine particle number concentrations

NASA Astrophysics Data System (ADS)

Ragettli, Martina S.; Ducret-Stich, Regina E.; Foraster, Maria; Morelli, Xavier; Aguilera, Inmaculada; Basagaña, Xavier; Corradi, Elisabetta; Ineichen, Alex; Tsai, Ming-Yi; Probst-Hensch, Nicole; Rivera, Marcela; Slama, Rémy; Künzli, Nino; Phuleria, Harish C.

2014-10-01

Methods are needed to characterize short-term exposure to ultrafine particle number concentrations (UFP) for epidemiological studies on the health effects of traffic-related UFP. Our aims were to assess season-specific spatial variation of short-term (20-min) UFP within the city of Basel, Switzerland, and to develop hybrid models for predicting short-term median and mean UFP levels on sidewalks. We collected measurements of UFP for periods of 20 min (MiniDiSC particle counter) and determined traffic volume along sidewalks at 60 locations across the city, during non-rush hours in three seasons. For each monitoring location, detailed spatial characteristics were locally recorded and potential predictor variables were derived from geographic information systems (GIS). We built multivariate regression models to predict local UFP, using concurrent UFP levels measured at a suburban background station, and combinations of meteorological, temporal, GIS and observed site characteristic variables. For a subset of sites, we assessed the relationship between UFP measured on the sidewalk and at the nearby residence (i.e., home outdoor exposure on e.g. balconies). The average median 20-min UFP levels at street and urban background sites were 14,700 ± 9100 particles cm-3 and 9900 ± 8600 particles cm-3, respectively, with the highest levels occurring in winter and the lowest in summer. The most important predictor for all models was the suburban background UFP concentration, explaining 50% and 38% of the variability of the median and mean, respectively. While the models with GIS-derived variables (R2 = 0.61) or observed site characteristics (R2 = 0.63) predicted median UFP levels equally well, mean UFP predictions using only site characteristic variables (R2 = 0.62) showed a better fit than models using only GIS variables (R2 = 0.55). The best model performance was obtained by using a combination of GIS-derived variables and locally observed site characteristics (median: R2 = 0.66; mean: R2 = 0.65). The 20-min UFP concentrations measured at the sidewalk were strongly related (R2 = 0.8) to the concurrent 20-min residential UFP levels nearby. Our results indicate that median UFP can be moderately predicted by means of a suburban background site and GIS-derived traffic and land use variables. In areas and regions where large-scale GIS data are not available, the spatial distribution of traffic-related UFP may be assessed reasonably well by collecting on-site short-term traffic and land-use data.

Application of imaging spectrometer in gas analysis by Raman scattering

NASA Astrophysics Data System (ADS)

Zuo, Duluo; Yu, Anlan; Li, Zhe; Wang, Xingbing; Xiong, Youhui

2015-09-01

Spontaneous Raman scattering is an effective technique in gas analysis, but the detection of minor constituents is difficult because of the low signal level and the usually existed background. Imaging spectrometer can provide highly spatial resolved spectra, so it should be much easier to pick up Raman signal of minor constituents from the Raman/fluorescence background of the sample cell and transporting optics compared with the widely used fiber-coupled spectrometers. For this reason, an imaging spectrometer was constructed from transmitting volume phase holographic grating, camera lenses and CCD detector. When it was used to analyze the gas sample in metal-lined capillary, which is a sample cell believed with great enhancement of Raman signal, the background was compressed obviously. When it was used to analyze the gas in a sample cell including a parabolic reflector, only weak background signal was observed, as the wide separation between the collecting zone (the focus point of the parabolic surface) and the wall of sample cell benefitted to the analysis by imaging spectrometer. By using the last sample cell, the signal from CO2 in ambient air was able to be found by an exposure time about 20 sec, and limits of detection for H2, CO2 and CO were estimated as 60 ppm, 100 ppm and 300 ppm respectively by the results of a longer exposure time. These results show that an imaging spectrometer paired with a well-arranged sample cell will lower the detecting limit effectively.

Feasibility of a cohort study on health risks caused by occupational exposure to radiofrequency electromagnetic fields

PubMed Central

2009-01-01

Background The aim of this study was to examine the feasibility of performing a cohort study on health risks from occupational exposure to radiofrequency electromagnetic fields (RF-EMF) in Germany. Methods A set of criteria was developed to evaluate the feasibility of such a cohort study. The criteria aimed at conditions of exposure and exposure assessment (level, duration, preferably on an individual basis), the possibility to assemble a cohort and the feasibility of ascertaining various disease endpoints. Results Twenty occupational settings with workers potentially exposed to RF-EMF and, in addition, a cohort of amateur radio operators were considered. Based on expert ratings, literature reviews and our set of predefined criteria, three of the cohorts were identified as promising for further evaluation: the personnel (technicians) of medium/short wave broadcasting stations, amateur radio operators, and workers on dielectric heat sealers. After further analyses, the cohort of workers on dielectric heat sealers seems not to be feasible due to the small number of exposed workers available and to the difficulty of assessing exposure (exposure depends heavily on the respective working process and mixture of exposures, e.g. plastic vapours), although exposure was highest in this occupational setting. The advantage of the cohort of amateur radio operators was the large number of persons it includes, while the advantage of the cohort of personnel working at broadcasting stations was the quality of retrospective exposure assessment. However, in the cohort of amateur radio operators the exposure assessment was limited, and the cohort of technicians was hampered by the small number of persons working in this profession. Conclusion The majority of occupational groups exposed to RF-EMF are not practicable for setting up an occupational cohort study due to the small numbers of exposed subjects or due to exposure levels being only marginally higher than those of the general public. PMID:19480652

Exposure of the endangered golden monkey (Rhinopithecus roxellana) to heavy metals: a comparison of wild and captive animals.

PubMed

Liu, Qiang; Chen, Yi-Ping; Maltby, Lorraine; Ma, Qing-Yi

2015-05-01

Golden monkeys are endemic to China and of high conservation concern. Conservation strategies include captive breeding, but the success of captive breeding programs may be being compromised by environmental pollution. Heavy metal exposure of wild and captive golden monkeys living in the Qinling Mountains was assessed by measuring fecal metal concentrations (As, Cd, Cr, Co, Cu, Mn, Hg, Ni, Pb, and Zn). Captive monkeys were exposed to higher concentrations of As, Hg, Pb, and Cr than monkeys living in the wild, while high background levels of Mn led to high exposure of wild monkeys. Seasonal variations in metal exposures were detected for both wild and captive monkeys; possible reasons being seasonal changes in either diet (wild monkeys) or metal content of food (captive monkeys). Coal combustion, waste incineration, and traffic-related activities were identified as possible sources of heavy metals exposure for captive animals. Efforts to conserve this endangered primate are potentially compromised by metal pollutants derived from increasing anthropogenic activities. Providing captive animals with uncontaminated food and relocating captive breeding centers away from sources of pollution will reduce pollutant exposure; but ultimately, there is a need to improve environmental quality by controlling pollutants at source.

Race/Ethnicity, Socioeconomic Status, Residential Segregation, and Spatial Variation in Noise Exposure in the Contiguous United States

PubMed Central

Morello-Frosch, Rachel; Mennitt, Daniel J.; Fristrup, Kurt; Ogburn, Elizabeth L.; James, Peter

2017-01-01

Background: Prior research has reported disparities in environmental exposures in the United States, but, to our knowledge, no nationwide studies have assessed inequality in noise pollution. Objectives: We aimed to a) assess racial/ethnic and socioeconomic inequalities in noise pollution in the contiguous United States; and b) consider the modifying role of metropolitan level racial residential segregation. Methods: We used a geospatial sound model to estimate census block group–level median (L50) nighttime and daytime noise exposure and 90th percentile (L10) daytime noise exposure. Block group variables from the 2006–2010 American Community Survey (ACS) included race/ethnicity, education, income, poverty, unemployment, homeownership, and linguistic isolation. We estimated associations using polynomial terms in spatial error models adjusted for total population and population density. We also evaluated the relationship between race/ethnicity and noise, stratified by levels of metropolitan area racial residential segregation, classified using a multigroup dissimilarity index. Results: Generally, estimated nighttime and daytime noise levels were higher for census block groups with higher proportions of nonwhite and lower-socioeconomic status (SES) residents. For example, estimated nighttime noise levels in urban block groups with 75% vs. 0% black residents were 46.3 A-weighted decibels (dBA) [interquartile range (IQR): 44.3–47.8 dBA] and 42.3 dBA (IQR: 40.4–45.5 dBA), respectively. In urban block groups with 50% vs. 0% of residents living below poverty, estimated nighttime noise levels were 46.9 dBA (IQR: 44.7–48.5 dBA) and 44.0 dBA (IQR: 42.2–45.5 dBA), respectively. Block groups with the highest metropolitan area segregation had the highest estimated noise exposures, regardless of racial composition. Results were generally consistent between urban and suburban/rural census block groups, and for daytime and nighttime noise and robust to different spatial weight and neighbor definitions. Conclusions: We found evidence of racial/ethnic and socioeconomic differences in model-based estimates of noise exposure throughout the United States. Additional research is needed to determine if differences in noise exposure may contribute to health disparities in the United States. https://doi.org/10.1289/EHP898 PMID:28749369

Environmental tobacco smoke in hospitality venues in Greece

PubMed Central

Vardavas, Constantine I; Kondilis, Barbara; Travers, Mark J; Petsetaki, Elisabeth; Tountas, Yiannis; Kafatos, Anthony G

2007-01-01

Background Exposure to environmental tobacco smoke is a major threat to public health. Greece, having the highest smoking prevalence in the European Union is seriously affected by passive smoking. The purpose of this study was to measure environmental tobacco smoke (ETS) exposure in the non smoking areas of hospitality venues and offices in Greece and to compare the levels of exposure to levels in the US, UK and Ireland before and after the implementation of a smoking ban. Methods Experimental measurements of particulate matter 2.5 μm (PM2.5), performed during a cross sectional study of 49 hospitality venues and offices in Athens and Crete, Greece during February – March 2006. Results Levels of ETS ranged from 19 μg/m3 to 612 μg/m3, differing according to the place of measurement. The average exposure in hospitality venues was 268 μg/m3 with ETS levels found to be highest in restaurants with a mean value of 298 μg/m3 followed by bars and cafes with 271 μg/m3. ETS levels were 76% lower in venues in which smoking was not observed compared to all other venues (p < 0.001). ETS levels in Greek designated non-smoking areas are similar to those found in the smoking sections of UK hospitality venues while levels in Ireland with a total smoking ban are 89% lower and smoke-free communities in the US are 91 – 96% lower than levels in Greece. Conclusion Designated non-smoking areas of hospitality venues in Greece are significantly more polluted with ETS than outdoor air and similar venues in Europe and the United States. The implementation of a total indoor smoking ban in hospitality venues has been shown to have a positive effect on workers and patrons' health. The necessity of such legislation in Greece is thus warranted. PMID:17956612

Lead in School Children from Morelos, Mexico: Levels, Sources and Feasible Interventions

PubMed Central

Farías, Paulina; Álamo-Hernández, Urinda; Mancilla-Sánchez, Leonardo; Texcalac-Sangrador, José Luis; Carrizales-Yáñez, Leticia; Riojas-Rodríguez, Horacio

2014-01-01

Background: Lead is a pervasive pollutant, associated at low levels to many adverse health effects. Objective: To investigate lead levels, exposure pathways and intervention possibilities in school children from Alpuyeca, in Morelos, Mexico. Methods: Blood lead concentrations (BPb) were measured in 226 children in 2011. Exposure pathways were assessed through a questionnaire, lead measurements in different environmental matrices and spatial aggregation analysis of lead concentrations. Results: BPb ranged from 1.5 to 36.5 µg/dL, with a mean (SD) of 7.23 (4.9) µg/dL. Sixty-four and 18% of the children had BPb > 5 µg/dL and > 10 µg/dL, respectively. The use of lead glazed ceramics was reported in almost half of the households; it was the main BPb determinant and it was associated with an increased risk of having BPb > 5 g/dL by 2.7 times (p = 0.001). Environmental samples were within US EPA’s lead recommended limits, and blood lead levels were randomly distributed in the community. Conclusions: Lead remains a public health problem in Alpuyeca, Mexico. Unlike other local pollutants, lead exposure prevention can be achieved inexpensively and in a short term. Interventions should make mothers aware of lead’s health effects and empower them to safeguard their children’s health by avoiding the culturally ingrained use of lead glazed pottery. PMID:25493390

Changes in levels of biomarkers of exposure observed in a controlled study of smokers switched from conventional to reduced toxicant prototype cigarettes.

PubMed

Shepperd, Christopher J; Eldridge, Alison; Camacho, Oscar M; McAdam, Kevin; Proctor, Christopher J; Meyer, Ingo

2013-06-01

Reduced toxicant prototype (RTP) cigarettes with substantially reduced levels of tobacco smoke toxicants have been developed. Evaluation of these prototype cigarettes included measurement of biomarkers of exposure (BoE) to toxicants in smokers switched from conventional cigarettes to the RTPs. A 6-week single-blinded randomised controlled study with occasional clinical confinement was conducted ( ISRCTN7215735). All smoking subjects smoked a conventional cigarette for 2-weeks. Control groups continued to smoke the conventional cigarette while test groups switched to one of three RTP designs. Clinical confinement and additional assessments were performed for all smoking groups after 2 and 4-weeks. A non-smoker group provided background levels of BoE. On average, smokers switched to RTPs with reduced machine yields of toxicants had reduced levels of corresponding BoEs. For vapour phase toxicants such as acrolein and 1,3-butadiene reductions of ⩾70% were observed both in smoke chemistry and BoEs. Reductions in particulate phase toxicants such as tobacco-specific nitrosamines, aromatic amines and polyaromatic hydrocarbons depended upon the technologies used, but were in some cases ⩾80% although some increases in other particulate phase toxicants were observed. However, reductions in BoEs demonstrate that it is possible to produce prototype cigarettes that reduce exposure to toxicants in short-term use. Copyright © 2013 Elsevier Inc. All rights reserved.

Prioritizing Chemicals and Data Requirements for Screening-Level Exposure and Risk Assessment

PubMed Central

Brown, Trevor N.; Wania, Frank; Breivik, Knut; McLachlan, Michael S.

2012-01-01

Background: Scientists and regulatory agencies strive to identify chemicals that may cause harmful effects to humans and the environment; however, prioritization is challenging because of the large number of chemicals requiring evaluation and limited data and resources. Objectives: We aimed to prioritize chemicals for exposure and exposure potential and obtain a quantitative perspective on research needs to better address uncertainty in screening assessments. Methods: We used a multimedia mass balance model to prioritize > 12,000 organic chemicals using four far-field human exposure metrics. The propagation of variance (uncertainty) in key chemical information used as model input for calculating exposure metrics was quantified. Results: Modeled human concentrations and intake rates span approximately 17 and 15 orders of magnitude, respectively. Estimates of exposure potential using human concentrations and a unit emission rate span approximately 13 orders of magnitude, and intake fractions span 7 orders of magnitude. The actual chemical emission rate contributes the greatest variance (uncertainty) in exposure estimates. The human biotransformation half-life is the second greatest source of uncertainty in estimated concentrations. In general, biotransformation and biodegradation half-lives are greater sources of uncertainty in modeled exposure and exposure potential than chemical partition coefficients. Conclusions: Mechanistic exposure modeling is suitable for screening and prioritizing large numbers of chemicals. By including uncertainty analysis and uncertainty in chemical information in the exposure estimates, these methods can help identify and address the important sources of uncertainty in human exposure and risk assessment in a systematic manner. PMID:23008278

A National Study on Nurses' Exposure to Occupational Violence in Lebanon: Prevalence, Consequences and Associated Factors.

PubMed

Alameddine, Mohamad; Mourad, Yara; Dimassi, Hani

2015-01-01

Healthcare institutions have commonly reported exposure of employees, particularly nurses, to high levels of occupational violence. Despite such evidence in the Middle East Region, there is a dearth of national studies that have systematically investigated this phenomenon. This study investigates the prevalence, characteristics, consequences and factors associated with nurses' exposure to occupational violence in Lebanon. A cross-sectional design was utilized to survey a nationally representative sample of 915 nurses registered with the Order of Nurses in Lebanon. Stratified random sampling by governorate was utilized. Individually-mailed questionnaires collected information on exposure to violence, degree of burnout and demographic/professional background. The main outcome variables were exposure to verbal abuse (never, 1-3, 4-9 and 10+ times) and physical violence (never, ever) over the past 12-months. Descriptive statistics were used to estimate prevalence of violence. Multivariable, binomial and multinomial regression models were carried out to investigate the correlates of exposure to verbal abuse and physical violence, respectively. Response rate was 64.8%. Over the last year, prevalence of nurses' exposure to verbal abuse was 62%, (CI: 58-65%) and physical violence was 10%, (CI: 8-13%). Among respondents, 31.7% of nurses indicated likelihood to quit their jobs and 22.3% were undetermined. Furthermore, 54.1% reported high levels of emotional exhaustion and 28.8% reported high levels of depersonalization. Compared to nurses with no exposure to verbal abuse, nurses reporting high exposure had high levels of emotional exhaustion (OR:6.4; CI:1.76-23.32), depersonalization (OR:6.8; CI: 3-15) and intention to quit job (OR:3.9; CI: 1.8-8.3). They further reported absence of anti-violence policies at their institutions (OR: 3; CI: 1.5-6.3). Nurses that were ever exposed to physical violence were more likely to be males (OR: 2.2; CI: 1.1-4.3), working day and night shifts (OR: 2.8; CI: 1.4-5.5) and subject to ten or more incidents of verbal abuse per year (OR: 46.7; CI: 10.1-214). An alarming two-thirds of respondents reported exposure to verbal abuse which was found to be a significant predictor of the three subscales of burnout, intention to quit and exposure to physical violence. The prevalence of exposure to physical violence is disconcerting due to its severe consequences. Policy and decision-makers are urged to use study findings for policy and practice interventions to create safe work environments conducive to nurses' productivity and retention.

Malondialdehyde-Deoxyguanosine Adduct Formation in Workers of Pathology Wards. The Role of Air Formaldehyde Exposure

PubMed Central

Romanazzi, Valeria; Munnia, Armelle; Piro, Sara; Allione, Alessandra; Ricceri, Fulvio; Guarrera, Simonetta; Pignata, Cristina; Matullo, Giuseppe; Wang, Poguang; Giese, Roger W.; Peluso, Marco

2010-01-01

Background Formaldehyde is a ubiquitous pollutant to which humans are exposed. Pathologists can experience high formaldehyde exposure levels. Formaldehyde – among other properties – induce oxidative stress and free radicals, which react with DNA and lipids, leading to oxidative damage and lipid peroxidation, respectively. We measured the levels of air-formaldehyde exposure in a group of Italian pathologists and controls. We analyzed the effect of formaldehyde exposure on leukocyte malondialdehyde-deoxyguanosine adducts (M1-dG), a biomarker of oxidative stress and lipid peroxidation. We studied the relationship between air-formaldehyde and M1-dG adducts. Methods Air-formaldehyde levels were measured by personal air samplers. M1-dG adducts were analyzed by 32P-postlabelling assay. Results Reduction rooms pathologists were significantly exposed to air-formaldehyde in respect to controls and to the pathologists working in other laboratory areas (p<0.001). A significant difference for M1-dG adducts between exposed pathologists and controls was found (p=0.045). The effect becomes stronger when the evaluation of air-formaldehyde exposure was based on personal samplers (p=0.018). Increased M1dG adduct levels were only found in individuals exposed to air-formaldehyde concentrations higher than 66 μg/m3. When the exposed workers and controls were subgrouped according to smoking, M1-dG tended to increase in all the subjects but a significant association between M1-dG and air-formaldehyde was only found in not smokers (p= 0.009). Air formaldehyde played a role positive but not significant (r = 0.355, p = 0.075, Pearson correlation) in the formation of M1-dG, only in not smokers. Conclusions Working in the reduction rooms and to be exposed to air-formaldehyde concentrations higher than 66 μg/m3 is associated with increased levels of M1-dG adducts. PMID:20707408

Genomics Study of the Exposure Effect of Gymnodinium catenatum, a Paralyzing Toxin Producer, on Crassostrea gigas' Defense System and Detoxification Genes

PubMed Central

García-Lagunas, Norma; Romero-Geraldo, Reyna; Hernández-Saavedra, Norma Y.

2013-01-01

Background Crassostrea gigas accumulates paralytic shellfish toxins (PST) associated with red tide species as Gymnodinium catenatum. Previous studies demonstrated bivalves show variable feeding responses to toxic algae at physiological level; recently, only one study has reported biochemical changes in the transcript level of the genes involved in C. gigas stress response. Principal Findings We found that 24 h feeding on toxic dinoflagellate cells (acute exposure) induced a significant decrease in clearance rate and expression level changes of the genes involved in antioxidant defense (copper/zinc superoxide dismutase, Cu/Zn-SOD), cell detoxification (glutathione S-transferase, GST and cytochrome P450, CPY450), intermediate immune response activation (lipopolysaccharide and beta glucan binding protein, LGBP), and stress responses (glutamine synthetase, GS) in Pacific oysters compared to the effects with the non-toxic microalga Isochrysis galbana. A sub-chronic exposure feeding on toxic dinoflagellate cells for seven and fourteen days (30×103 cells mL−1) showed higher gene expression levels. A significant increase was observed in Cu/Zn-SOD, GST, and LGBP at day 7 and a major increase in GS and CPY450 at day 14. We also observed that oysters fed only with G. catenatum (3×103 cells mL−1) produced a significant increase on the transcription level than in a mixed diet (3×103 cells mL−1 of G. catenatum+0.75×106 cells mL−1 I. galbana) in all the analyzed genes. Conclusions Our results provide gene expression data of PST producer dinoflagellate G. catenatum toxic effects on C. gigas, a commercially important bivalve. Over expressed genes indicate the activation of a potent protective mechanism, whose response depends on both cell concentration and exposure time against these toxic microalgae. Given the importance of dinoflagellate blooms in coastal environments, these results provide a more comprehensive overview of how oysters respond to stress generated by toxic dinoflagellate exposure. PMID:24039751

Environmental arsenic exposure and risk of diabetes type 2 in Ron Phibun subdistrict, Nakhon Si Thammarat Province, Thailand: unmatched and matched case–control studies

PubMed Central

Sripaoraya, Kwanyuen; Siriwong, Wattasit; Pavittranon, Sumol; Chapman, Robert S

2017-01-01

Background There are inconsistent findings on associations between low-to-moderate level of arsenic in water and diabetes risk from previous epidemiological reports. In Ron Phibun subdistrict, Nakhon Si Thammarat Province, Thailand, a low level of arsenic exposure among population was observed and increased diabetes mellitus (DM) rate was identified. Objectives We aimed to investigate the association between determinants (including low-level water arsenic exposure) of DM type 2 risk among residents of three villages of Ron Phibun subdistrict, Nakhon Si Thammarat Province. Materials and methods Secondary data from two previous community based-studies, conducted in 2000 and 2008, were utilized. Data on independent variables relating to arsenic exposure and sociodemographic characteristics were taken from questionnaires and worksheets for health-risk screening. Water samples collected during household visit were sent for analysis of arsenic level at certified laboratories. Diabetes cases (N=185) were those who had been diagnosed with DM type 2. Two groups of controls, one unmatched to cases (n=200) and one pair matched on age and gender (n=200), were selected for analysis as unmatched and matched case–control studies, respectively. A multiple imputation technique was used to impute missing values of independent variables. Multivariable logistic regression models, with independent variables for arsenic exposure and sociodemographic characteristics, were constructed. The unmatched and matched data sets were analyzed using unconditional and conditional logistic analyses, respectively. Results Older age, body mass index (BMI), having a history of illness in siblings and parents, and drinking were associated with increased DM type 2 risk. We found no convincing association between DM type 2 risk and water arsenic concentration in either study. Conclusion We did not observe meaningful association between diabetes risk and the low-to-moderate arsenic levels observed in this study. Further research is needed to confirm this finding in the study area and elsewhere in Thailand. PMID:28442938

Evaluation of the Effect of Noise on the Rate of Errors and Speed of Work by the Ergonomic Test of Two-Hand Co-Ordination

PubMed Central

Habibi, Ehsanollah; Dehghan, Habibollah; Dehkordy, Sina Eshraghy; Maracy, Mohammad Reza

2013-01-01

Background: Among the most important and effective factors affecting the efficiency of the human workforce are accuracy, promptness, and ability. In the context of promoting levels and quality of productivity, the aim of this study was to investigate the effects of exposure to noise on the rate of errors, speed of work, and capability in performing manual activities. Methods: This experimental study was conducted on 96 students (52 female and 44 male) of the Isfahan Medical Science University with the average and standard deviations of age, height, and weight of 22.81 (3.04) years, 171.67 (8.51) cm, and 65.05 (13.13) kg, respectively. Sampling was conducted with a randomized block design. Along with controlling for intervening factors, a combination of sound pressure levels [65 dB (A), 85 dB (A), and 95 dB (A)] and exposure times (0, 20, and 40) were used for evaluation of precision and speed of action of the participants, in the ergonomic test of two-hand coordination. Data was analyzed by SPSS18 software using a descriptive and analytical statistical method by analysis of covariance (ANCOVA) repeated measures. Results: The results of this study showed that increasing sound pressure level from 65 to 95 dB in network ‘A’ increased the speed of work (P < 0.05). Increase in the exposure time (0 to 40 min of exposure) and gender showed no significant differences statistically in speed of work (P > 0.05). Male participants got annoyed from the noise more than females. Also, increase in sound pressure level increased the rate of error (P < 0.05). Conclusions: According to the results of this research, increasing the sound pressure level decreased efficiency and increased the errors and in exposure to sounds less than 85 dB in the beginning, the efficiency decreased initially and then increased in a mild slope. PMID:23930164

Persistent Organochlorine Pollutants with Endocrine Activity and Blood Steroid Hormone Levels in Middle-Aged Men

PubMed Central

Emeville, Elise; Giton, Frank; Giusti, Arnaud; Oliva, Alejandro; Fiet, Jean; Thomé, Jean-Pierre; Blanchet, Pascal; Multigner, Luc

2013-01-01

Background Studies relating long-term exposure to persistent organochlorine pollutants (POPs) with endocrine activities (endocrine disrupting chemicals) on circulating levels of steroid hormones have been limited to a small number of hormones and reported conflicting results. Objective We examined the relationship between serum concentrations of dehydroepiandrosterone, dehydroepiandrosterone sulphate, androstenedione, androstenediol, testosterone, free and bioavailable testosterone, dihydrotestosterone, estrone, estrone sulphate, estradiol, sex-hormone binding globulin, follicle-stimulating hormone, and luteinizing hormone as a function of level of exposure to three POPs known to interfere with hormone-regulated processes in different way: dichlorodiphenyl dichloroethene (DDE), polychlorinated biphenyl (PCB) congener 153, and chlordecone. Methods We collected fasting, morning serum samples from 277 healthy, non obese, middle-aged men from the French West Indies. Steroid hormones were determined by gas chromatography-mass spectrometry, except for dehydroepiandrosterone sulphate, which was determined by immunological assay, as were the concentrations of sex-hormone binding globulin, follicle-stimulating hormone and luteinizing hormone. Associations were assessed by multiple linear regression analysis, controlling for confounding factors, in a backward elimination procedure, in multiple bootstrap samples. Results DDE exposure was negatively associated to dihydrotestosterone level and positively associated to luteinizing hormone level. PCB 153 was positively associated to androstenedione and estrone levels. No association was found for chlordecone. Conclusions These results suggested that the endocrine response pattern, estimated by determining blood levels of steroid hormones, varies depending on the POPs studied, possibly reflecting differences in the modes of action generally attributed to these compounds. It remains to be investigated whether this response pattern is predictive of the subsequent occurrence of disease. PMID:23785499

Effects of manganese on routine semen quality parameters: results from a population-based study in China

PubMed Central

2012-01-01

Background Manganese (Mn) is an essential element in humans but its effect on semen quality is unclear. This study therefore aimed to assess the effects of Mn on semen quality in healthy men with no occupational exposure to Mn. Methods Semen samples were obtained from healthy Chinese men 20–59 years old who were recruited from six provinces in China. Individuals with urogenital tract diseases, tuberculosis, or occupational exposure to heavy metals were excluded. A questionnaire survey was conducted, and the external genitalia, semen quality, and serum Mn levels were examined. Results A total of 1,179 volunteers were enrolled in this study. The median serum Mn concentration was 8.2 μg/L (25th percentile (P25)=3.7 μg/L, P75=16.2μg/L). After adjusted area (six provinces), abstinence interval, season, registered residence, age of subjects, education level, income, smoking, and drinking, the risk of teratospermia was increased at serum Mn concentrations >19.40 μg/L (P80) group, with an adjusted odds ratio of 2.27 (95% confidence interval: 1.18–4.37). Conclusion High serum Mn levels appeared to have harmful effects on sperm morphology and motility among healthy men with no occupational exposure to Mn. PMID:23107312

Validating novel air pollution sensors to improve exposure estimates for epidemiological analyses and citizen science.

PubMed

Jerrett, Michael; Donaire-Gonzalez, David; Popoola, Olalekan; Jones, Roderic; Cohen, Ronald C; Almanza, Estela; de Nazelle, Audrey; Mead, Iq; Carrasco-Turigas, Glòria; Cole-Hunter, Tom; Triguero-Mas, Margarita; Seto, Edmund; Nieuwenhuijsen, Mark

2017-10-01

Low cost, personal air pollution sensors may reduce exposure measurement errors in epidemiological investigations and contribute to citizen science initiatives. Here we assess the validity of a low cost personal air pollution sensor. Study participants were drawn from two ongoing epidemiological projects in Barcelona, Spain. Participants repeatedly wore the pollution sensor - which measured carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO 2 ). We also compared personal sensor measurements to those from more expensive instruments. Our personal sensors had moderate to high correlations with government monitors with averaging times of 1-h and 30-min epochs (r ~ 0.38-0.8) for NO and CO, but had low to moderate correlations with NO 2 (~0.04-0.67). Correlations between the personal sensors and more expensive research instruments were higher than with the government monitors. The sensors were able to detect high and low air pollution levels in agreement with expectations (e.g., high levels on or near busy roadways and lower levels in background residential areas and parks). Our findings suggest that the low cost, personal sensors have potential to reduce exposure measurement error in epidemiological studies and provide valid data for citizen science studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Geochemistry and health risk assessment of arsenic exposure to street dust in the zinc smelting district, Northeast China.

PubMed

Xu, Sujuan; Zheng, Na; Liu, Jingshuang; Wang, Yang; Chang, Shouzhi

2013-02-01

The aim of this study was to investigate arsenic (As) accumulation in street dust and health risk of population. The investigation concentrated on: a. pollution levels of As in street dust; b. spatial distribution of As in street dust; c. physicochemical properties analysis of street dust; and d. assessment of population health risk due to As exposure to street dust. As concentration in street dust ranged from 3.33 to 185.1 mg kg(-1), with a mean of 33.10 mg kg(-1), which was higher than the background value of Liaoning soil. As contamination level of the area closing to Huludao Zinc Plant (HZP) was highest. Spatial variation showed that the pollution center was close to HZP, formed radial distribution pattern and extended to the northeast and southwest of HZP. The pH and organic matter of street dust were both higher than the background values of soil in Liaoning. There was significantly negative correlation between As concentration and the pH. The mass percentages of particles 180-100, <100-75, <75-63, and <63 μm were 29.8, 3.7, 21.3, and 4.2 %, respectively. The highest of As concentration was found in the smallest particle size (<63 μm). As loadings in the particles of grain size 180-100 and <75-63 μm were higher than other particle fractions. Results of the risk assessment indicated that the highest risk was associated with the ingestion of street dust particles. Health risk for different use scenarios to human decreased in the order of HZP > Industrial district > School > Commercial center > Residential area. Around HZP, Hazard Index (HI) for children and cancer risk of As by street dust exposure exceeded the acceptable values. It indicated that there was a potential adverse effect on children health by As exposure to the street dust of Huludao.

Mortality among the residents of the Three Mile Island accident area: 1979-1992.

PubMed

Talbott, E O; Youk, A O; McHugh, K P; Shire, J D; Zhang, A; Murphy, B P; Engberg, R A

2000-06-01

The largest U.S. population exposed to low-level radioactivity released by an accident at a nuclear power plant is composed of residents near the Three Mile Island (TMI) Plant on 28 March 1979. This paper (a collaboration of The University of Pittsburgh and the Pennsylvania Department of Health) reports on the mortality experience of the 32,135 members in this cohort for 1979-1992. We analyzed standardized mortality ratios (SMRs) using a local comparison population and performed relative risk regression modeling to assess overall mortality and specific cancer risks by confounding factors and radiation-related exposure variables. Total mortality was significantly elevated for both men and women (SMRs = 109 and 118, respectively). All heart disease accounted for 43.3% of total deaths and demonstrated elevated SMRs for heart disease of 113 and 130 for men and women, respectively; however, when controlling for confounders and natural background radiation, these elevations in heart disease were no longer evident. Overall cancer mortality was similar in this cohort as compared to the local population (male SMR = 100; female SMR = 101). In the relative risk modeling, there was a significant effect for all lymphatic and hematopoietic tissue in males in relation to natural background exposure (p = 0.04). However, no trend was noted. We found a significant linear trend for female breast cancer risk in relation to increasing levels of TMI-related likely [gamma]-exposure (p = 0.02). Although such a relationship has been noted in other investigations, emissions from the TMI incident were significantly lower than in other documented studies. Therefore, it is unlikely that this observed increase is related to radiation exposure on the day of the accident. The mortality surveillance of this cohort does not provide consistent evidence that radioactivity released during the TMI accident has a significant impact on the mortality experience of this cohort to date. However, continued follow-up of these individuals will provide a more comprehensive description of the morbidity and mortality experience of the cohort.

An Intervention to Reduce Residential Insecticide Exposure during Pregnancy among an Inner-City Cohort

PubMed Central

Williams, Megan K.; Barr, Dana B.; Camann, David E.; Cruz, Linda A.; Carlton, Elizabeth J.; Borjas, Mejico; Reyes, Andria; Evans, Dave; Kinney, Patrick L.; Whitehead, Ralph D.; Perera, Frederica P.; Matsoanne, Stephen; Whyatt, Robin M.

2006-01-01

Background We previously reported widespread insecticide exposure during pregnancy among inner-city women from New York City. Here we report on a pilot intervention using integrated pest management (IPM) to reduce pest infestations and residential insecticide exposures among pregnant New York City African-American and Latina women (25 intervention and 27 control homes). Methods The IPM consisted of professional cleaning, sealing of pest entry points, application of low-toxicity pesticides, and education. Cockroach infestation levels and 2-week integrated indoor air samples were collected at baseline and one month postintervention. The insecticides detected in the indoor air samples were also measured in maternal and umbilical cord blood collected at delivery. Results Cockroach infestations decreased significantly (p = 0.016) after the intervention among intervention cases but not control households. Among the intervention group, levels of piperonyl butoxide (a pyrethroid synergist) were significantly lower in indoor air samples after the intervention (p = 0.016). Insecticides were detected in maternal blood samples collected at delivery from controls but not from the intervention group. The difference was significant for trans-permethrin (p = 0.008) and of borderline significance (p = 0.1) for cis-permethrin and 2-isopropoxyphenol (a propoxur metabolite). Conclusion To our knowledge, this is the first study to use biologic dosimeters of prenatal pesticide exposure for assessing effectiveness of IPM. These pilot data suggest that IPM is an effective strategy for reducing pest infestation levels and the internal dose of insecticides during pregnancy. PMID:17107853

Levels and predictors of urinary nickel concentrations of children in Germany: results from the German Environmental Survey on children (GerES IV).

PubMed

Wilhelm, Michael; Wittsiepe, Jürgen; Seiwert, Margarete; Hünken, Andreas; Becker, Kerstin; Conrad, André; Schulz, Christine; Kolossa-Gehring, Marike

2013-03-01

Human biomonitoring of nickel has gained interest in environmental medicine due to its wide distribution in the environment and its allergenic potential. There are indications that the prevalence of nickel sensitization in children is increased by nickel exposure and that oral uptake of nickel can exacerbate nickel dermatitis in nickel-sensitive individuals. Urinary nickel measurement is a good indicator of exposure. However, data on nickel levels in urine of children are rare. For the first time, the German Environmental Survey on children (GerES IV) 2003-2006 provided representative data to describe the internal nickel exposure of children aged 3-14 years in Germany. Nickel was measured after enrichment in the organic phase of urine by graphite furnace atomic absorption spectrometry with Zeeman background correction. Nickel levels (n=1576) ranged from <0.5 to 15 μg/l. Geometric mean was 1.26 μg/l. Multivariate regression analysis showed that gender, age, socio-economic status, being overweighted, consumption of hazelnut spread, nuts, cereals, chocolate and urinary creatinine were significant predictors for urinary nickel excretion of children who do not smoke. 20.2% of the variance could be explained by these variables. With a contribution of 13.8% the urinary creatinine concentration was the most important predictor. No influence of nickel intake via drinking water and second hand smoke exposure was observed. Copyright © 2012 Elsevier GmbH. All rights reserved.

Environmental Noise Pollution in the United States: Developing an Effective Public Health Response

PubMed Central

Hammer, Monica S.; Swinburn, Tracy K.

2013-01-01

Background: Tens of millions of Americans suffer from a range of adverse health outcomes due to noise exposure, including heart disease and hearing loss. Reducing environmental noise pollution is achievable and consistent with national prevention goals, yet there is no national plan to reduce environmental noise pollution. Objectives: We aimed to describe some of the most serious health effects associated with noise, summarize exposures from several highly prevalent noise sources based on published estimates as well as extrapolations made using these estimates, and lay out proven mechanisms and strategies to reduce noise by incorporating scientific insight and technological innovations into existing public health infrastructure. Discussion: We estimated that 104 million individuals had annual LEQ(24) levels > 70 dBA (equivalent to a continuous average exposure level of >70 dBA over 24 hr) in 2013 and were at risk of noise-induced hearing loss. Tens of millions more may be at risk of heart disease, and other noise-related health effects. Direct regulation, altering the informational environment, and altering the built environment are the least costly, most logistically feasible, and most effective noise reduction interventions. Conclusion: Significant public health benefit can be achieved by integrating interventions that reduce environmental noise levels and exposures into the federal public health agenda. Citation: Hammer MS, Swinburn TK, Neitzel RL. 2014. Environmental noise pollution in the United States: developing an effective public health response. Environ Health Perspect 122:115–119; http://dx.doi.org/10.1289/ehp.1307272 PMID:24311120

Cement Dust Exposure and Perturbations in Some Elements and Lung and Liver Functions of Cement Factory Workers

PubMed Central

Richard, Egbe Edmund; Augusta Chinyere, Nsonwu-Anyanwu; Jeremaiah, Offor Sunday; Opara, Usoro Chinyere Adanna; Henrieta, Etukudo Maise; Ifunanya, Egbe Deborah

2016-01-01

Background. Cement dust inhalation is associated with deleterious health effects. The impact of cement dust exposure on the peak expiratory flow rate (PEFR), liver function, and some serum elements in workers and residents near cement factory were assessed. Methods. Two hundred and ten subjects (50 workers, 60 residents, and 100 controls) aged 18–60 years were studied. PEFR, liver function {aspartate and alanine transaminases (AST and ALT) and total and conjugated bilirubin (TB and CB)}, and serum elements {lead (Pb), copper (Cu), manganese (Mn), iron (Fe), cadmium (Cd), selenium (Se), chromium (Cr), zinc (Zn), and arsenic (As)} were determined using peak flow meter, colorimetry, and atomic absorption spectrometry, respectively. Data were analysed using ANOVA and correlation at p = 0.05. Results. The ALT, TB, CB, Pb, As, Cd, Cr, Se, Mn, and Cu were significantly higher and PEFR, Fe, and Zn lower in workers and residents compared to controls (p < 0.05). Higher levels of ALT, AST, and Fe and lower levels of Pb, Cd, Cr, Se, Mn, and Cu were seen in cement workers compared to residents (p < 0.05). Negative correlation was observed between duration of exposure and PEFR (r = −0.416, p = 0.016) in cement workers. Conclusions. Cement dust inhalation may be associated with alterations in serum elements levels and lung and liver functions while long term exposure lowers peak expiratory flow rate. PMID:26981118

Association of Radon Background and Total Background Ionizing Radiation with Alzheimer's Disease Deaths in U.S. States.

PubMed

Lehrer, Steven; Rheinstein, Peter H; Rosenzweig, Kenneth E

2017-01-01

Exposure of the brain to ionizing radiation might promote the development of Alzheimer's disease (AD). Analysis of AD death rates versus radon background radiation and total background radiation in U.S. states. Total background, radon background, cosmic and terrestrial background radiation measurements are from Assessment of Variations in Radiation Exposure in the United States and Report No. 160 - Ionizing Radiation Exposure of the Population of the United States. 2013 AD death rates by U.S. state are from the Alzheimer's Association. Radon background ionizing radiation was significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.467, p = 0.001). Total background ionizing radiation was also significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.452, p = 0.001). Multivariate linear regression weighted by state population demonstrated that AD death rate was significantly correlated with radon background (β= 0.169, p < 0.001), age (β= 0.231, p < 0.001), hypertension (β= 0.155, p < 0.001), and diabetes (β= 0.353, p < 0.001). Our findings, like other studies, suggest that ionizing radiation is a risk factor for AD. Intranasal inhalation of radon gas could subject the rhinencephalon and hippocampus to damaging radiation that initiates AD. The damage would accumulate over time, causing age to be a powerful risk factor.

A radon progeny deposition model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rielage, Keith; Elliott, Steven R; Hime, Andrew

2010-12-01

The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly {sup 222}Rn) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of {sup 210}Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean roommore » environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.« less

Inverse association of intellectual function with very low blood lead but not with manganese exposure in Italian adolescents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lucchini, Roberto G., E-mail: lucchini@med.unibs.it; Section of Occupational Medicine, University of Brescia, P.le Spedali Civili 1, 25123 Brescia; Zoni, Silvia

Background: Pediatric lead (Pb) exposure impacts cognitive function and behavior and co-exposure to manganese (Mn) may enhance neurotoxicity. Objectives: To assess cognitive and behavioral function in adolescents with environmental exposure to Pb and Mn. Methods: In this cross sectional study, cognitive function and behavior were examined in healthy adolescents with environmental exposure to metals. The Wechsler Intelligence Scale for Children (WISC) and the Conners-Wells' Adolescent Self-Report Scale Long Form (CASS:L) were used to assess cognitive and behavioral function, respectively. ALAD polymorphisms rs1800435 and rs1139488 were measured as potential modifiers. Results: We examined 299 adolescents (49.2% females) aged 11-14 years. Bloodmore » lead (BPb) averaged 1.71 {mu}g/dL (median 1.5, range 0.44-10.2), mean Blood Manganese (BMn) was 11.1 {mu}g/dL (median 10.9, range 4.00-24.1). Average total IQ was 106.3 (verbal IQ=102, performance IQ=109.3). According to a multiple regression model considering the effect of other covariates, a reduction of about 2.4 IQ points resulted from a two-fold increase of BPb. The Benchmark Level of BPb associated with a loss of 1 IQ-point (BML01) was 0.19 {mu}g/dL, with a lower 95% confidence limit (BMLL01) of 0.11 {mu}g/dL. A very weak correlation resulted between BPb and the ADHD-like behavior (Kendall's tau rank correlation=0.074, p=0.07). No influence of ALAD genotype was observed on any outcome. Manganese was not associated with cognitive and behavioral outcomes, nor was there any interaction with lead. Conclusions: These findings demonstrate that very low level of lead exposure has a significant negative impact on cognitive function in adolescent children. Being an essential micro-nutrient, manganese may not cause cognitive effects at these low exposure levels.« less

A simulation study to quantify the impacts of exposure ...

EPA Pesticide Factsheets

BackgroundExposure measurement error in copollutant epidemiologic models has the potential to introduce bias in relative risk (RR) estimates. A simulation study was conducted using empirical data to quantify the impact of correlated measurement errors in time-series analyses of air pollution and health.MethodsZIP-code level estimates of exposure for six pollutants (CO, NOx, EC, PM2.5, SO4, O3) from 1999 to 2002 in the Atlanta metropolitan area were used to calculate spatial, population (i.e. ambient versus personal), and total exposure measurement error.Empirically determined covariance of pollutant concentration pairs and the associated measurement errors were used to simulate true exposure (exposure without error) from observed exposure. Daily emergency department visits for respiratory diseases were simulated using a Poisson time-series model with a main pollutant RR = 1.05 per interquartile range, and a null association for the copollutant (RR = 1). Monte Carlo experiments were used to evaluate the impacts of correlated exposure errors of different copollutant pairs.ResultsSubstantial attenuation of RRs due to exposure error was evident in nearly all copollutant pairs studied, ranging from 10 to 40% attenuation for spatial error, 3–85% for population error, and 31–85% for total error. When CO, NOx or EC is the main pollutant, we demonstrated the possibility of false positives, specifically identifying significant, positive associations for copoll

Combining a Job-Exposure Matrix with Exposure Measurements to Assess Occupational Exposure to Benzene in a Population Cohort in Shanghai, China

PubMed Central

Friesen, Melissa C.; Coble, Joseph B.; Lu, Wei; Shu, Xiao-Ou; Ji, Bu-Tian; Xue, Shouzheng; Portengen, Lutzen; Chow, Wong-Ho; Gao, Yu-Tang; Yang, Gong; Rothman, Nathaniel; Vermeulen, Roel

2012-01-01

Background: Generic job-exposure matrices (JEMs) are often used in population-based epidemiologic studies to assess occupational risk factors when only the job and industry information of each subject is available. JEM ratings are often based on professional judgment, are usually ordinal or semi-quantitative, and often do not account for changes in exposure over time. We present an empirical Bayesian framework that combines ordinal subjective JEM ratings with benzene measurements. Our aim was to better discriminate between job, industry, and time differences in exposure levels compared to using a JEM alone. Methods: We combined 63 221 short-term area air measurements of benzene exposure (1954–2000) collected during routine health and safety inspections in Shanghai, China, with independently developed JEM intensity ratings for each job and industry using a mixed-effects model. The fixed-effects terms included the JEM intensity ratings for job and industry (both ordinal, 0–3) and a time trend that we incorporated as a b-spline. The random-effects terms included job (n = 33) and industry nested within job (n = 399). We predicted the benzene concentration in two ways: (i) a calibrated JEM estimate was calculated using the fixed-effects model parameters for calendar year and JEM intensity ratings; (ii) a job-/industry-specific estimate was calculated using the fixed-effects model parameters and the best linear unbiased predictors from the random effects for job and industry using an empirical Bayes estimation procedure. Finally, we applied the predicted benzene exposures to a prospective population-based cohort of women in Shanghai, China (n = 74 942). Results: Exposure levels were 13 times higher in 1965 than in 2000 and declined at a rate that varied from 4 to 15% per year from 1965 to 1985, followed by a small peak in the mid-1990s. The job-/industry-specific estimates had greater differences between exposure levels than the calibrated JEM estimates (97.5th percentile/2.5th percentile exposure level, BGR95B: 20.4 versus 3.0, respectively). The calibrated JEM and job-/industry-specific estimates were moderately correlated in any given year (Pearson correlation, rp = 0.58). We classified only those jobs and industries with a job or industry JEM exposure probability rating of 3 (>50% of workers exposed) as exposed. As a result, 14.8% of the subjects and 8.7% of the employed person-years in the study population were classified as benzene exposed. The cumulative exposure metrics based on the calibrated JEM and job-/industry-specific estimates were highly correlated (rp = 0.88). Conclusions: We provide a useful framework for combining quantitative exposure data with expert-based exposure ratings in population-based studies that maximized the information from both sources. Our framework calibrated the ratings to a concentration scale between ratings and across time and provided a mechanism to estimate exposure when a job/industry group reported by a subject was not represented in the exposure database. It also allowed the job/industry groups’ exposure levels to deviate from the pooled average for their respective JEM intensity ratings. PMID:21976309

Particle exposure and inhaled dose during commuting in Singapore

NASA Astrophysics Data System (ADS)

Tan, Sok Huang; Roth, Matthias; Velasco, Erik

2017-12-01

Exposure concentration and inhaled dose of particles during door-to-door trips walking and using motorized transport modes (subway, bus, taxi) are evaluated along a selected route in a commercial district of Singapore. Concentrations of particles smaller than 2.5 μm in size (PM2.5), black carbon, particle-bound polycyclic aromatic hydrocarbons, number of particles, active surface area and carbon monoxide have been measured in-situ using portable instruments. Simultaneous measurements were conducted at a nearby park to capture the background concentrations. The heart rate of the participants was monitored during the measurements as a proxy of the inhalation rate used to calculate the inhaled dose of particles. All measured metrics were highest and well above background levels during walking. No significant difference was observed in the exposure concentration of PM2.5 for the three motorized transport modes, unlike for the metrics associated with ultrafine particles (UFP). The concentration of these freshly emitted particles was significantly lower on subway trips. The absence of combustion sources, use of air conditioning and screen doors at station platforms are effective measures to protect passengers' health. For other transport modes, sections of trips close to accelerating and idling vehicles, such as bus stops, traffic junctions and taxi stands, represent hotspots of particles. Reducing the waiting time at such locations will lower pollutants exposure and inhaled dose during a commute. After taking into account the effect of inhalation and travel duration when calculating dose, the health benefit of commuting by subway for this particular district of Singapore became even more evident. For example, pedestrians breathe in 2.6 and 3.2 times more PM2.5 and UFP, respectively than subway commuters. Public buses were the second best alternative. Walking emerged as the worst commuting mode in terms of particle exposure and inhaled dose.

Environmental tobacco smoke exposure and periodontitis prevalence among nonsmokers in the hispanic community Health Study/Study of Latinos.

PubMed

Akinkugbe, Aderonke A; Sanders, Anne E; Preisser, John S; Cai, Jianwen; Salazar, Christian R; Beck, James D

2017-04-01

To describe self-reported exposure to environmental tobacco smoke (ETS) and its association with periodontitis prevalence in a diverse group of Hispanics/Latinos. Data came from 8675 lifetime nonsmokers in the 2008-2011 Hispanic Community Health Study/Study of Latinos. Exposure to ETS was self-reported, while periodontitis was defined using the Centers for Disease Control and Prevention-American Academy of Periodontology criteria and the proportion of sites affected by clinical attachment level of ≥3 mm or pocket depth of ≥4 mm. Survey logistic regression estimated prevalence odds ratios (POR) and 95% confidence intervals (CI). In addition, we assessed whether greater hours of exposure to ETS in the past year was associated with greater periodontitis prevalence, and lastly, we conducted a simple sensitivity analysis of ETS misclassification. Age-standardized prevalence estimates (95% CI) for ETS exposure and periodontitis were 57.6% (55.9, 59.4) and 39.8% (38.1, 41.4), respectively. After adjusting for confounders and periodontitis risk factors, we estimated an overall adjusted POR (95% CI) for the ETS-periodontitis association as 1.09 (0.95-1.26) with a confidence limit ratio (CLR) of 1.34. This association varied in magnitude by Hispanic/Latino background, ranging from 1.04 (0.75, 1.43 with a CLR = 1.91) among Central Americans to 1.76 (1.16, 2.66 with a CLR = 2.29) in Puerto Ricans. Previously reported associations between ETS and periodontitis appear weak in this study. However, the magnitude of the association differs according to Hispanic/Latino background. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dioxin Exposure Initiative

EPA Pesticide Factsheets

The Dioxin Exposure Initiative (DEI) is no longer active. This page contains a summary of the dioxin exposure initiative with illustrations, contact and background information.Originally supported by scientist Matthew Lorber, who retired in Mar 2017.

RESIDENTIAL EXPOSURE TO EXTREMELY LOW FREQUENCY ELECTRIC AND MAGNETIC FIELDS IN THE CITY OF RAMALLAH-PALESTINE.

PubMed

Abuasbi, Falastine; Lahham, Adnan; Abdel-Raziq, Issam Rashid

2018-04-01

This study was focused on the measurement of residential exposure to power frequency (50-Hz) electric and magnetic fields in the city of Ramallah-Palestine. A group of 32 semi-randomly selected residences distributed amongst the city were under investigations of fields variations. Measurements were performed with the Spectrum Analyzer NF-5035 and were carried out at one meter above ground level in the residence's bedroom or living room under both zero and normal-power conditions. Fields' variations were recorded over 6-min and some times over few hours. Electric fields under normal-power use were relatively low; ~59% of residences experienced mean electric fields <10 V/m. The highest mean electric field of 66.9 V/m was found at residence R27. However, electric field values were log-normally distributed with geometric mean and geometric standard deviation of 9.6 and 3.5 V/m, respectively. Background electric fields measured under zero-power use, were very low; ~80% of residences experienced background electric fields <1 V/m. Under normal-power use, the highest mean magnetic field (0.45 μT) was found at residence R26 where an indoor power substation exists. However, ~81% of residences experienced mean magnetic fields <0.1 μT. Magnetic fields measured inside the 32 residences showed also a log-normal distribution with geometric mean and geometric standard deviation of 0.04 and 3.14 μT, respectively. Under zero-power conditions, ~7% of residences experienced average background magnetic field >0.1 μT. Fields from appliances showed a maximum mean electric field of 67.4 V/m from hair dryer, and maximum mean magnetic field of 13.7 μT from microwave oven. However, no single result surpassed the ICNIRP limits for general public exposures to ELF fields, but still, the interval 0.3-0.4 μT for possible non-thermal health impacts of exposure to ELF magnetic fields, was experienced in 13% of the residences.

Variability of total exposure to PM2.5 related to indoor and outdoor pollution sources Krakow study in pregnant women.

PubMed

Jedrychowski, Wieslaw A; Perera, Frederica P; Pac, Agnieszka; Jacek, Ryszard; Whyatt, Robin M; Spengler, John D; Dumyahn, Thomas S; Sochacka-Tatara, Elzbieta

2006-07-31

The study is a part of an ongoing prospective cohort study on the relationship between the exposure to environmental factors during pregnancy and birth outcomes and health of newborns. We have measured personal PM(2.5) level in the group of 407 non-smoking pregnant women during the 2nd trimester of pregnancy. On average, the participants from the city center were exposed to higher exposure than those from the outer city area (GM=42.0 microg/m(3), 95% CI: 36.8-48.0 vs. 35.8 microg/m(3), 95% CI: 33.5-38.2 microg/m(3)). More than 20% of study subjects were affected by high level of PM(2.5) pollution (above 65 microg/m(3)). PM(2.5) concentrations were higher during the heating season (GM=43.4 microg/m(3), 95% CI: 40.1-46.9 microg/m(3)) compared to non-heating season (GM=29.8 microg/m(3), 95% CI: 27.5-32.2 microg/m(3)). Out of all potential outdoor air pollution sources (high traffic density, bus depot, waste incinerator, industry etc.) considered in the bivariate analysis, only the proximity of industrial plant showed significant impact on the personal exposure (GM=54.3 microg/m(3), 95% CI: 39.4-74.8 microg/m(3)) compared with corresponding figure for those who did not declare living near the industrial premises (GM=36.2 microg/m(3), 95% CI: 34.1-38.4 microg/m(3)). The subjects declaring high exposure to ETS (>10 cigarettes daily) have shown very high level of personal exposure (GM=88.8 microg/m(3), 95% CI: 73.9-106.7 microg/m(3)) compared with lower ETS exposure (< or =10 cigarettes) (GM=46.3 microg/m(3), 95% CI: 40.0-53.5 microg/m(3)) and no-ETS exposure group (GM=33.9 microg/m(3), 95% CI: 31.8-36.1 microg/m(3)). The contribution of the background ambient PM(10) level was very strong determinant of the total personal exposure to PM(2.5) and it explained about 31% of variance between the subjects followed by environmental tobacco smoke (10%), home heating by coal/wood stoves (2%), other types of heating (2%) and the industrial plant localization in the proximity of household (1%).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Yueh-Ying, E-mail: hany2@upmc.edu; Youk, Ada O., E-mail: ayouk@pitt.edu; Sasser, Howell, E-mail: howell_sasser@nymc.edu

Background: The Pennsylvania Department of Health established a registry of the Three Mile Island (TMI) nuclear power plant accident in 1979. Over 93% of the population present on the day of the accident within a 5-mile radius was enrolled and interviewed. We used the registry to investigate the potential cancer risk from low-dose radiation exposure among the TMI population. Methods: Cancer incidence data among the TMI cohort were available from 1982 to 1995. Because more than 97% of the population were white and few cancer cases were reported for those younger than 18 years of age, we included whites ofmore » age 18 years and older (10,446 men and 11,048 women) for further analyses. Cox regression models were used to estimate the relative risk (RR) per 0.1 m Sv and 95% confident interval (CI) of cancer by radiation-related exposures. The cancers of interest were all malignant neoplasms, cancer of bronchus, trachea, and lung, cancer of lymphatic and hematopoietic tissues, leukemia, and female breast. Results: Among men and women, there was no evidence of an increased risk for all malignant neoplasms among the TMI cohort exposed to higher maximum and likely {gamma} radiation (RR=1.00, 95% CI=0.97, 1.01 and RR=0.99, 95% CI=0.94, 1.03, respectively) after adjusting for age, gender, education, smoking, and background radiation. Elevation in risk was noted for cancer of the bronchus, trachea, and lung in relation to higher background radiation exposure (RR=1.45, 95% CI=1.02-2.05 at 8.0-8.8 {mu}R/h compared to 5.2-7.2 {mu}R/h). An increased risk of leukemia was found among men exposed to higher maximum and likely {gamma} radiation related to TMI exposure during the ten days following the accident (RR=1.15, 95% CI=1.04, 1.29 and RR=1.36, 95% CI=1.08, 1.71, respectively). This relationship was not found in women. Conclusion: Increased cancer risks from low-level radiation exposure within the TMI cohort were small and mostly statistically non-significant. However, additional follow-up on this population is warranted, especially to explore the increased risk of leukemia found in men.« less

Effects of wind on background particle concentrations at truck freight terminals.

PubMed

Garcia, Ronald; Hart, Jaime E; Davis, Mary E; Reaser, Paul; Natkin, Jonathan; Laden, Francine; Garshick, Eric; Smith, Thomas J

2007-01-01

Truck freight terminals are predominantly located near highways and industrial facilities. This proximity to pollution sources, coupled with meteorological conditions and wind patterns, may affect occupational exposures to particles at these work locations. To understand this process, data from an environmental sampling study of particles at U.S. trucking terminals, along with weather and geographic maps, were analyzed to determine the extent to which the transportation of particles from local pollutant sources elevated observed occupational exposures at these locations. To help identify potential upwind sources, wind direction weighted averages and speed measurements were used to construct wind roses that were superimposed on overhead photos of the terminal and examined for upwind source activity. Statistical tests were performed on these "source" and "nonsource" directions to determine whether there were significant differences in observed particle levels between the two groups. Our results provide evidence that nearby upwind pollution sources significantly elevated background concentrations at only a few of the locations sampled, whereas the majority provided little to no evidence of a significant upwind source effect.

Determination of an environmental background level of 90Sr in urine for the Hanford bioassay program.

PubMed

Antonio, C L; Rivard, J W

2009-11-01

During the decommissioning and maintenance of some of the facilities at the U.S. Department of Energy Hanford Site in Washington State, workers have potential for a Sr intake. However, because of worldwide radioactive fallout, Sr is present in our environment and can be detectable in routine urine bioassay samples. It is important for the Hanford Site bioassay program to discriminate an occupational intake from a non-occupational environmental one. A detailed study of the background Sr in the urine of unexposed Hanford workers was performed. A survey of the Hanford Site bioassay database found 128 Hanford workers who were hired between 1997 and 2002 and who had a very low potential for an occupational exposure prior to the baseline strontium urinalysis. Each urinalysis sample represented excretion during an approximate 24-h period. The arithmetic mean value for the 128 pre-exposure baselines was 3.6 +/- 5.1 mBq d. The 99 percentile result was 17 mBq d, which was interpreted to mean that 1% of Hanford workers not occupationally exposed to strontium might exceed 17 mBq d.

Search for proton decay via p →e+π0 and p →μ+π0 in 0.31 megaton.years exposure of the Super-Kamiokande water Cherenkov detector

NASA Astrophysics Data System (ADS)

Abe, K.; Haga, Y.; Hayato, Y.; Ikeda, M.; Iyogi, K.; Kameda, J.; Kishimoto, Y.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakajima, T.; Nakano, Y.; Nakayama, S.; Orii, A.; Sekiya, H.; Shiozawa, M.; Takeda, A.; Tanaka, H.; Tomura, T.; Wendell, R. A.; Akutsu, R.; Irvine, T.; Kajita, T.; Kaneyuki, K.; Nishimura, Y.; Richard, E.; Okumura, K.; Labarga, L.; Fernandez, P.; Gustafson, J.; Kachulis, C.; Kearns, E.; Raaf, J. L.; Stone, J. L.; Sulak, L. R.; Berkman, S.; Nantais, C. M.; Tanaka, H. A.; Tobayama, S.; Goldhaber, M.; Kropp, W. R.; Mine, S.; Weatherly, P.; Smy, M. B.; Sobel, H. W.; Takhistov, V.; Ganezer, K. S.; Hartfiel, B. L.; Hill, J.; Hong, N.; Kim, J. Y.; Lim, I. T.; Park, R. G.; Himmel, A.; Li, Z.; O'Sullivan, E.; Scholberg, K.; Walter, C. W.; Wongjirad, T.; Ishizuka, T.; Tasaka, S.; Jang, J. S.; Learned, J. G.; Matsuno, S.; Smith, S. N.; Friend, M.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Suzuki, A. T.; Takeuchi, Y.; Yano, T.; Cao, S. V.; Hiraki, T.; Hirota, S.; Huang, K.; Kikawa, T.; Minamino, A.; Nakaya, T.; Suzuki, K.; Fukuda, Y.; Choi, K.; Itow, Y.; Suzuki, T.; Mijakowski, P.; Frankiewicz, K.; Hignight, J.; Imber, J.; Jung, C. K.; Li, X.; Palomino, J. L.; Wilking, M. J.; Yanagisawa, C.; Fukuda, D.; Ishino, H.; Kayano, T.; Kibayashi, A.; Koshio, Y.; Mori, T.; Sakuda, M.; Xu, C.; Kuno, Y.; Tacik, R.; Kim, S. B.; Okazawa, H.; Choi, Y.; Nishijima, K.; Koshiba, M.; Totsuka, Y.; Suda, Y.; Yokoyama, M.; Bronner, C.; Hartz, M.; Martens, K.; Marti, Ll.; Suzuki, Y.; Vagins, M. R.; Martin, J. F.; Konaka, A.; Chen, S.; Zhang, Y.; Wilkes, R. J.; Super-Kamiokande Collaboration

2017-01-01

We have searched for proton decay via p →e+π0 and p →μ+π0 using Super-Kamiokande data from April 1996 to March 2015, 0.306 megaton .years exposure in total. The atmospheric neutrino background rate in Super-Kamiokande IV is reduced to almost half that of phase I-III by tagging neutrons associated with neutrino interactions. The reach of the proton lifetime is further enhanced by introducing new signal criteria that select the decay of a proton in a hydrogen atom. No candidates were seen in the p →e+π0 search. Two candidates that passed all of the selection criteria for p →μ+π0 have been observed, but these are consistent with the expected number of background events of 0.87. Lower limits on the proton lifetime are set at τ /B (p →e+π0)>1.6 ×1 034 years and τ /B (p →μ+π0)>7.7 ×1 033 years at 90% confidence level.

Human phase response curve to a 1 h pulse of bright white light

PubMed Central

St Hilaire, Melissa A; Gooley, Joshua J; Khalsa, Sat Bir S; Kronauer, Richard E; Czeisler, Charles A; Lockley, Steven W

2012-01-01

The phase resetting response of the human circadian pacemaker to light depends on the timing of exposure and is described by a phase response curve (PRC). The current study aimed to construct a PRC for a 1 h exposure to bright white light (∼8000 lux) and to compare this PRC to a <3 lux dim background light PRC. These data were also compared to a previously completed 6.7 h bright white light PRC and a <15 lux dim background light PRC constructed under similar conditions. Participants were randomized for exposure to 1 h of either bright white light (n= 18) or <3 lux dim background light (n= 18) scheduled at 1 of 18 circadian phases. Participants completed constant routine (CR) procedures in dim light (<3 lux) before and after the light exposure to assess circadian phase. Phase shifts were calculated as the difference in timing of dim light melatonin onset (DLMO) during pre- and post-stimulus CRs. Exposure to 1 h of bright white light induced a Type 1 PRC with a fitted peak-to-trough amplitude of 2.20 h. No discernible PRC was observed in the <3 lux dim background light PRC. The fitted peak-to-trough amplitude of the 1 h bright light PRC was ∼40% of that for the 6.7 h PRC despite representing only 15% of the light exposure duration, consistent with previous studies showing a non-linear duration–response function for the effects of light on circadian resetting. PMID:22547633

Human phase response curve to a 1 h pulse of bright white light.

PubMed

St Hilaire, Melissa A; Gooley, Joshua J; Khalsa, Sat Bir S; Kronauer, Richard E; Czeisler, Charles A; Lockley, Steven W

2012-07-01

The phase resetting response of the human circadian pacemaker to light depends on the timing of exposure and is described by a phase response curve (PRC). The current study aimed to construct a PRC for a 1 h exposure to bright white light (∼8000 lux) and to compare this PRC to a <3 lux dim background light PRC. These data were also compared to a previously completed 6.7 h bright white light PRC and a <15 lux dim background light PRC constructed under similar conditions. Participants were randomized for exposure to 1 h of either bright white light (n=18) or <3 lux dim background light (n=18) scheduled at 1 of 18 circadian phases. Participants completed constant routine (CR) procedures in dim light (<3 lux) before and after the light exposure to assess circadian phase. Phase shifts were calculated as the difference in timing of dim light melatonin onset (DLMO) during pre- and post-stimulus CRs. Exposure to 1 h of bright white light induced a Type 1 PRC with a fitted peak-to-trough amplitude of 2.20 h. No discernible PRC was observed in the <3 lux dim background light PRC. The fitted peak-to-trough amplitude of the 1 h bright light PRC was ∼40% of that for the 6.7 h PRC despite representing only 15% of the light exposure duration, consistent with previous studies showing a non-linear duration–response function for the effects of light on circadian resetting.

First Attempt To Validate Human IgG Antibody Response to Nterm-34kDa Salivary Peptide as Biomarker for Evaluating Exposure to Aedes aegypti Bites

PubMed Central

Elanga Ndille, Emmanuel; Doucoure, Souleymane; Damien, Georgia; Mouchet, François; Drame, Papa Makhtar; Cornelie, Sylvie; Noukpo, Herbert; Yamadjako, Sandra; Djenontin, Armel; Moiroux, Nicolas; Misse, Dorothee; Akogbeto, Martin; Corbel, Vincent; Henry, Marie-Claire; Chandre, Fabrice; Baldet, Thierry; Remoue, Franck

2012-01-01

Background Much effort is being devoted for developing new indicators to evaluate the human exposure to Aedes mosquito bites and the risk of arbovirus transmission. Human antibody (Ab) responses to mosquito salivary components could represent a promising tool for evaluating the human-vector contact. Methodology/Principal findings To develop a specific biomarker of human exposure to Aedes aegypti bites, we measured IgG Ab response to Ae. aegypti Nterm-34 kDa salivary peptide in exposed children in 7 villages of Southern Benin (West Africa). Results showed that specific IgG response presented high inter-individual heterogeneity between villages. IgG response was associated with rainfall and IgG level increased from dry (low exposure) to rainy (high exposure) seasons. These findings indicate that IgG Ab to Nterm-34 kDa salivary peptide may represent a reliable biomarker to detect variation in human exposure to Ae. aegypti bites. Conclusion/Significance This preliminary study highlights the potential use of Ab response to this salivary peptide for evaluating human exposure to Ae. aegypti. This biomarker could represent a new promising tool for assessing the risk of arbovirus transmission and for evaluating the efficacy of vector control interventions. PMID:23166852

Prevalence of Hypertension by Duration and Age at Exposure to the Stroke Belt

PubMed Central

Howard, Virginia J; Woolson, Robert F.; Egan, Brent M.; Nicholas, Joyce S.; Adams, Robert J.; Howard, George; Lackland, Daniel T.

2010-01-01

Background Geographic variation in hypertension is hypothesized as contributing to the stroke belt, an area in southeastern United States with high stroke mortality. No study has examined hypertension by lifetime exposure to the stroke belt. Methods This association was studied in 19 385 participants in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study, a national population-based cohort. Prevalent hypertension was defined as SBP ≥ 140, DBP ≥ 90, or use of antihypertensive medications. Stroke belt exposure was assessed by residence at birth, currently, early childhood, adolescence, early adulthood, mid-adulthood, and recently. Results After adjustment for age, race, sex, physical activity level, body mass index, smoking, alcohol, education, and income, the prevalence of hypertension was significantly more strongly related (p < 0.0001) with lifetime exposure, adolescence or early adulthood exposure than exposures at other times. Birthplace and current residence were independently associated with hypertension; however, lifetime, adolescence or early adulthood exposures were more predictive than joint model with both birthplace and current residence. Conclusions That adolescence and early adulthood periods are more predictive than residence in the stroke belt for most recent 20-year period suggests community and environmental strategies to prevent hypertension need to start earlier in life. PMID:20374949

Personality Traits and Combat Exposure as Predictors of Psychopathology Over Time

PubMed Central

Koffel, Erin; Kramer, Mark D.; Arbisi, Paul A.; Erbes, Christopher R.; Kaler, Matthew; Polusny, Melissa A.

2016-01-01

Background Research suggests that personality traits have both direct and indirect effects on the development of psychological symptoms, with indirect effects mediated by stressful or traumatic events. This study models the direct influence of personality traits on residualized changes in internalizing and externalizing symptoms following a stressful and potentially traumatic deployment, as well as the indirect influence of personality on symptom levels mediated by combat exposure. Method We utilized structural equation modeling with a longitudinal prospective study of 522 US National Guard soldiers deployed to Iraq. Analyses were based on self-report measures of personality, combat exposure, and internalizing and externalizing symptoms. Results Both pre-deployment Disconstraint and externalizing symptoms predicted combat exposure, which in turn predicted internalizing and externalizing symptoms. There was a significant indirect effect for pre-deployment externalizing symptoms on post-deployment externalizing via combat exposure (p < .01). Negative Emotionality and pre-deployment internalizing symptoms directly predicted post-deployment internalizing symptoms, but both were unrelated to combat exposure. No direct effects of personality on residualized changes in externalizing symptoms were found. Conclusions Baseline symptom dimensions had significant direct and indirect effects on post-deployment symptoms. Controlling for both pre-exposure personality and symptoms, combat experiences remained positively related to both internalizing and externalizing symptoms. Implications for diagnostic classification are discussed. PMID:26347314

Tea and coffee consumption in relation to vitamin D and calcium levels in Saudi adolescents

PubMed Central

2012-01-01

Background Coffee and tea consumption was hypothesized to interact with variants of vitamin D-receptor polymorphisms, but limited evidence exists. Here we determine for the first time whether increased coffee and tea consumption affects circulating levels of 25-hydroxyvitamin D in a cohort of Saudi adolescents. Methods A total of 330 randomly selected Saudi adolescents were included. Anthropometrics were recorded and fasting blood samples were analyzed for routine analysis of fasting glucose, lipid levels, calcium, albumin and phosphorous. Frequency of coffee and tea intake was noted. 25-hydroxyvitamin D levels were measured using enzyme-linked immunosorbent assays. Results Improved lipid profiles were observed in both boys and girls, as demonstrated by increased levels of HDL-cholesterol, even after controlling for age and BMI, among those consuming 9–12 cups of coffee/week. Vitamin D levels were significantly highest among those consuming 9–12 cups of tea/week in all subjects (p-value 0.009) independent of age, gender, BMI, physical activity and sun exposure. Conclusion This study suggests a link between tea consumption and vitamin D levels in a cohort of Saudi adolescents, independent of age, BMI, gender, physical activity and sun exposure. These findings should be confirmed prospectively. PMID:22905922

Ambient air benzene at background sites in China's most developed coastal regions: exposure levels, source implications and health risks.

PubMed

Zhang, Zhou; Wang, Xinming; Zhang, Yanli; Lü, Sujun; Huang, Zhonghui; Huang, Xinyu; Wang, Yuesi

2015-04-01

Benzene is a known human carcinogen causing leukemia, yet ambient air quality objectives for benzene are not available in China. The ambient benzene levels at four background sites in China's most developed coastal regions were measured from March 2012 to February 2013. The sites are: SYNECP, in the Northeast China Plain (NECP); YCNCP, in the North China Plain (NCP); THYRD, in the Yangtze River Delta (YRD) and DHPRD, in the Pearl River Delta (PRD). It was found that the mean annual benzene levels (578-1297 ppt) at the background sites were alarmingly higher, especially when compared to those of 60-480 pptv monitored in 28 cities in the United States. Wintertime benzene levels were significantly elevated at both sites (SYNECP and YCNCP) in northern China due to heating with coal/biofuels. Even at these background sites, the lifetime cancer risks of benzene (1.7-3.7E-05) all exceeded 1E-06 set by USEPA as acceptable for adults. At both sites in northern China, good correlations between benzene and CO or chloromethane, together with much lower toluene/benzene (T/B) ratios, suggested that benzene was largely related to coal combustion and biomass/biofuel burning. At the DHPRD site in the PRD, benzene revealed a highly significant correlation with methyl tert-butyl ether (MTBE), indicating that its source was predominantly from vehicle emissions. At the THYRD site in the YRD, higher T/B ratios and correlations between benzene and tetrachloroethylene, or MTBE, implied that benzene levels were probably affected by both traffic-related and industrial emissions. Copyright © 2015 Elsevier B.V. All rights reserved.

Summary of the development of a signature for detection of residual dust from collapse of the World Trade Center buildings

PubMed Central

Lowers, Heather A; Meeker, Gregory P; Lioy, Paul J; Lippmann, Morton

2014-01-01

The collapse of the World Trade Center (WTC) towers on September 11, 2001, caused lower Manhattan and adjacent areas to be covered in millimeters to centimeters of dust. WTC dust penetrated into indoor spaces, and public health concerns remain regarding exposure to possible residual dust in the affected areas. The goal of the studies outlined in this review was to determine which, if any, components of the bulk WTC dust are sufficiently above typical background dust levels in New York City to develop an analytical method to screen for the component(s). Components of the <150-µm-size fraction of the dust are gypsum, phases compatible with crushed concrete, man-made vitreous fibers (MMVFs), silica, lead, chrysotile asbestos, and other materials. Slag wool was the most common WTC MMVF, whereas soda-lime glass and rock wool were minor to trace constituents. Most background samples also contained gypsum, phases compatible with concrete, and MMVF. However, the proportions of the various MMVF in background samples are typically unlike those characteristic of bulk WTC dust. Results indicate that slag wool can be used as a signature marker to identify areas that contain potential residual WTC dust contamination at concentrations that are less than average background levels for the material. PMID:18478046

Topical Rapamycin Suppresses the Angiogenesis Pathways Induced by Pulsed Dye Laser: Molecular Mechanisms of Inhibition of Regeneration and Revascularization of Photocoagulated Cutaneous Blood Vessels

PubMed Central

Tan, Wenbin; Jia, Wangcun; Sun, Victor; Mihm, Martin C.; Nelson, J. Stuart

2014-01-01

Background and Objectives Pulsed dye laser (PDL) is the most effective treatment for port wine stain (PWS) birthmarks. However, regeneration and revascularization of photocoagulated blood vessels may result in poor therapeutic outcome. We have recently shown that rapamycin (RPM), an angiogenesis inhibitor, can reduce the regeneration and revascularization of photocoagulated blood vessels. Herein, we attempt to further elucidate the molecular pathophysiology on the inhibition of the regeneration and revascularization of photocoagulated blood vessels by topical RPM in an animal model. Materials and Methods Two separate skin areas on each hamster were irradiated by PDL. After PDL exposure, topical RPM was applied daily to one of the randomly selected test sites. PDL, PDL + RPM and normal skin test sites were biopsied on day 3 after PDL exposure. The total ribonucleic acid (RNA) and protein were extracted from biopsied skin samples and quantified. Real-time reverse transcription-polymerase chain reaction (RT-PCR) and immunoblot were subsequently performed to quantify the mRNA and protein levels of hypoxia-inducible factor-1alpha (HIF-1α), vascular endothelial growth factor (VEGF) and ribosomal protein S6 kinase (S6). The phosphorylation levels of S6 and AKT were also evaluated by immunoblot. Results The mRNA and protein levels of HIF-1α, VEGF, and S6 significantly increased after PDL exposure as compared to the normal hamster skin. Topical application of 1% RPM suppressed the PDL-induced increase in mRNA and protein levels of those genes on day 3 post-PDL exposure. The phosphorylation levels of S6 and AKT increased after PDL exposure but the increases were suppressed by the topical application of RPM. Conclusion The increase in expression of HIF-1α, VEGF, and S6 after PDL-exposure suggests that angiogenesis pathways play very active roles in the process of skin blood vessel regeneration and revascularization. Topical application of 1% RPM can suppress the angiogenesis pathways and, therefore, reduce the regeneration and revascularization of photocoagulated blood vessels. PMID:23213008

Effects of in Utero Exposure to Arsenic during the Second Half of Gestation on Reproductive End Points and Metabolic Parameters in Female CD-1 Mice

PubMed Central

Rodriguez, Karina F.; Ungewitter, Erica K.; Crespo-Mejias, Yasmin; Liu, Chang; Nicol, Barbara; Kissling, Grace E.; Yao, Humphrey Hung-Chang

2015-01-01

Background Mice exposed to high levels of arsenic in utero have increased susceptibility to tumors such as hepatic and pulmonary carcinomas when they reach adulthood. However, the effects of in utero arsenic exposure on general physiological functions such as reproduction and metabolism remain unclear. Objectives We evaluated the effects of in utero exposure to inorganic arsenic at the U.S. Environmental Protection Agency (EPA) drinking water standard (10 ppb) and at tumor-inducing levels (42.5 ppm) on reproductive end points and metabolic parameters when the exposed females reached adulthood. Methods Pregnant CD-1 mice were exposed to sodium arsenite [none (control), 10 ppb, or 42.5 ppm] in drinking water from gestational day 10 to birth, the window of organ formation. At birth, exposed offspring were fostered to unexposed dams. We examined reproductive end points (age at vaginal opening, reproductive hormone levels, estrous cyclicity, and fertility) and metabolic parameters (body weight changes, hormone levels, body fat content, and glucose tolerance) in the exposed females when they reached adulthood. Results Arsenic-exposed females (10 ppb and 42.5 ppm) exhibited early onset of vaginal opening. Fertility was not affected when females were exposed to the 10-ppb dose. However, the number of litters per female was decreased in females exposed to 42.5 ppm of arsenic in utero. In both 10-ppb and 42.5-ppm groups, arsenic-exposed females had significantly greater body weight gain, body fat content, and glucose intolerance. Conclusion Our findings revealed unexpected effects of in utero exposure to arsenic: exposure to both a human-relevant low dose and a tumor-inducing level led to early onset of vaginal opening and to obesity in female CD-1 mice. Citation Rodriguez KF, Ungewitter EK, Crespo-Mejias Y, Liu C, Nicol B, Kissling GE, Yao HH. 2016. Effects of in utero exposure to arsenic during the second half of gestation on reproductive end points and metabolic parameters in female CD-1 mice. Environ Health Perspect 124:336–343; http://dx.doi.org/10.1289/ehp.1509703 PMID:26295903

The role of protease-activated receptor-2 on pulmonary neutrophils in the innate immune response to cockroach allergen

PubMed Central

2012-01-01

Background Serine proteases in German cockroach (GC) have been shown to mediate allergic airway inflammation through the activation of protease activated receptor (PAR)-2. Neutrophils play an important role in regulating the innate immune response, and are recruited into the airways following GC frass exposure. As such, we investigated the role of PAR-2 in airway neutrophil recruitment, activation and cytokine production following allergen exposure. Methods Wild type and PAR-2-deficient mice were administered a single intratracheal instillation of PBS or GC frass and neutrophil recruitment, expression of PAR-2, CD80, CD86, and MHC class II were assessed by flow cytometry and levels of tumor necrosis factor (TNF)α was assessed by ELISA. Uptake of AlexaFluor 405-labeled GC frass by neutrophils was performed by flow cytometry. Results Neutrophil recruitment in the lung and airways following GC frass exposure was significantly decreased in PAR-2-deficient mice compared to wild type mice. GC frass exposure increased the level of PAR-2 on pulmonary neutrophils and increased numbers of PAR-2-positive neutrophils were found in the lungs; however PAR-2 did not play a role in meditating allergen uptake. Comparing wild type and PAR-2-deficient mice, we found that a single exposure to GC frass increased levels of CD80 and CD86 on pulmonary neutrophils, an effect which was independent of PAR-2 expression. Neutrophils isolated from the whole lungs of naïve PAR-2-deficient mice treated ex vivo with GC frass produced significantly less TNFα than in similarly treated wild type neutrophils. Lastly, neutrophils were isolated from the bronchoalveolar lavage fluid of wild type and PAR-2-deficient mice following a single intratracheal exposure to GC frass. Airway neutrophils from PAR-2-deficient mice released substantially decreased levels of TNFα, suggesting a role for PAR-2 in neutrophil-derived cytokine production. Conclusions Together these data suggest PAR-2 expression can be upregulated on lung neutrophils following allergen exposure and the consequence is altered release of TNFα which could drive the early innate immune response. PMID:22954301

Detection of fluorotelomer alcohols in indoor environments and their relevance for human exposure.

PubMed

Schlummer, Martin; Gruber, Ludwig; Fiedler, Dominik; Kizlauskas, Markus; Müller, Josef

2013-07-01

Fluorotelomer alcohols (FTOH) are important precursors of perfluorinated carboxylic acids (PFCA). These neutral and volatile compounds are frequently found in indoor air and may contribute to the overall human exposure to per- and polyfluorinated alkyl substances (PFAS). In this study air samples of ten workplace environments and a car interior were analysed. In addition, extracts and emissions from selected outdoor textiles were analysed in order to establish their potential contribution to the indoor levels of the above-mentioned compounds. Concentrations of FTOHs measured in air ranged from 0.15 to 46.8, 0.25 to 286, and 0.11 to 57.5ng/m(3) for 6:2, 8:2 and 10:2 FTOHs, respectively. The highest concentrations in air were identified in shops selling outdoor clothing, indicating outdoor textiles to be a relevant source of FTOH in indoor workplace environments. Total amounts of FTOH in materials of outdoor textiles accounted for <0.8-7.6, 12.1-180.9 and 4.65-105.7μg/dm(2) for 6:2, 8:2 and 10:2 FTOHs, respectively. Emission from selected textiles revealed emission rates of up to 494ng/h. The measured data show that a) FTOHs are present in indoor textiles (e.g. carpets), b) they are released at ambient temperatures and c) indoor air of shops selling outdoor textiles contains the highest levels of FTOH. Exposure of humans to perfluorooctanoic acid (PFOA) through absorption of FTOH and subsequent degradation is discussed on the basis of indoor air levels. Calculation of indoor air-related exposure using the median of the measured air levels revealed that exposure is on the same order of magnitude as the recently reported dietary intakes for a background-exposed population. On the basis of the 95th percentile, indoor air exposure to PFOA was estimated to exceed dietary exposure. However, indoor air-related intakes of FTOH are far below the tolerable daily intake (TDI) of PFOA, indicating that there is no risk to health, even when assuming an unrealistic complete degradation of FTOH into PFOA. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mercury Report-Children's exposure to elemental mercury

MedlinePlus

... gov . Mercury Background Mercury Report Additional Resources Mercury Report - Children's Exposure to Elemental Mercury Recommend on Facebook ... I limit exposure to mercury? Why was the report written? Children attending a daycare in New Jersey ...

Socioeconomic and urban-rural differentials in exposure to air pollution and mortality burden in England.

PubMed

Milojevic, Ai; Niedzwiedz, Claire L; Pearce, Jamie; Milner, James; MacKenzie, Ian A; Doherty, Ruth M; Wilkinson, Paul

2017-10-06

Socioeconomically disadvantaged populations often have higher exposures to particulate air pollution, which can be expected to contribute to differentials in life expectancy. We examined socioeconomic differentials in exposure and air pollution-related mortality relating to larger scale (5 km resolution) variations in background concentrations of selected pollutants across England. Ozone and particulate matter (sub-divided into PM 10 , PM 2.5 , PM 2.5-10 , primary, nitrate and sulphate PM 2.5 ) were simulated at 5 km horizontal resolution using an atmospheric chemistry transport model (EMEP4UK). Annual mean concentrations of these pollutants were assigned to all 1,202,578 residential postcodes in England, which were classified by urban-rural status and socioeconomic deprivation based on the income and employment domains of the 2010 English Index of Multiple Deprivation for the Lower-level Super Output Area of residence. We used life table methods to estimate PM 2.5 -attributable life years (LYs) lost in both relative and absolute terms. Concentrations of the most particulate fractions, but not of nitrate PM 2.5 or ozone, were modestly higher in areas of greater socioeconomic deprivation. Relationships between pollution level and socioeconomic deprivation were non-linear and varied by urban-rural status. The pattern of PM 2.5 concentrations made only a small contribution to the steep socioeconomic gradient in LYs lost due to PM 2.5 per 10 3 population, which primarily was driven by the steep socioeconomic gradient in underlying mortality rates. In rural areas, the absolute burden of air pollution-related LYs lost was lowest in the most deprived deciles. Air pollution shows modest socioeconomic patterning at 5 km resolution in England, but absolute attributable mortality burdens are strongly related to area-level deprivation because of underlying mortality rates. Measures that cause a general reduction in background concentrations of air pollution may modestly help narrow socioeconomic differences in health.

Evaluation of the risk of noise-induced hearing loss among unscreened male industrial workers.

PubMed

Prince, Mary M; Gilbert, Stephen J; Smith, Randall J; Stayner, Leslie T

2003-02-01

Variability in background risk and distribution of various risk factors for hearing loss may explain some of the diversity in excess risk of noise-induced hearing loss (NIHL). This paper examines the impact of various risk factors on excess risk estimates of NIHL using data from the 1968-1972 NIOSH Occupational Noise and Hearing Survey (ONHS). Previous analyses of a subset of these data focused on 1172 highly "screened" workers. In the current analysis, an additional 894 white males (609 noise-exposed and 285 controls), who were excluded for various reasons (i.e., nonoccupational noise exposure, otologic or medical conditions affecting hearing, prior occupational noise exposure) have been added 2066) to assess excess risk of noise-induced material impairment in an unscreened population. Data are analyzed by age, duration of exposure, and sound level (8-h TWA) for four different definitions of noise-induced hearing impairment, defined as the binaural pure-tone average (PTA) hearing threshold level greater than 25 dB for the following frequencies: (a) 1-4 kHz (PTA1234), (b) 1-3 kHz (PTA123), (c) 0.5, 1, and 2 kHz (PTA512), and (d) 3, 4, and 6 kHz (PTA346). Results indicate that populations with higher background risks of hearing loss may show lower excess risks attributable to noise relative to highly screened populations. Estimates of lifetime excess risk of hearing impairment were found to be significantly different between screened and unscreened population for noise levels greater than 90 dBA. Predicted age-related risk of material hearing impairment in the ONHS unscreened population was similar to that predicted from Annex B and C of ANSI S3.44 for ages less than 60 years. Results underscore the importance of understanding differential risk patterns for hearing loss and the use of appropriate reference (control) populations when evaluating risk of noise-induced hearing impairment among contemporary industrial populations.

Relationships of Polychlorinated Biphenyls and Dichlorodiphenyldichloroethylene (p,p’-DDE) with Testosterone Levels in Adolescent Males

PubMed Central

Gallo, Mia V.; Deane, Glenn D.; Nelder, Kyrie R.; DeCaprio, Anthony P.; Jacobs, Agnes

2013-01-01

Background: Concern persists over endocrine-disrupting effects of persistent organic pollutants (POPs) on human growth and sexual maturation. Potential effects of toxicant exposures on testosterone levels during puberty are not well characterized. Objectives: In this study we evaluated the relationship between toxicants [polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p´-DDE), hexachlorobenzene (HCB), and lead] and testosterone levels among 127 Akwesasne Mohawk males 10 to < 17 years of age with documented toxicant exposures. Methods: Data were collected between February 1996 and January 2000. Fasting blood specimens were collected before breakfast by trained Akwesasne Mohawk staff. Multivariable regression models were used to estimates associations between toxicants and serum testosterone, adjusted for other toxicants, Tanner stage, and potential confounders. Results: The sum of 16 PCB congeners (Σ16PCBs) that were detected in ≥ 50% of the population was significantly and negatively associated with serum testosterone levels, such that a 10% change in exposure was associated with a 5.6% decrease in testosterone (95% CI: –10.8, –0.5%). Of the 16 congeners, the more persistent ones (Σ8PerPCBs) were related to testosterone, whereas the less persistent ones, possibly reflecting more recent exposure, were not. When PCB congeners were subgrouped, the association was significant for the sum of eight more persistent PCBs (5.7% decrease; 95% CI: –11, –0.4%), and stronger than the sum of six less persistent congeners (3.1% decrease; 95% CI: –7.2, 0.9%). p,p´-DDE was positively but not significantly associated with serum testosterone (5.2% increase with a 10% increase in exposure; 95% CI: –0.5, 10.9%). Neither lead nor HCB was significantly associated with testosterone levels. Conclusions: Exposure to PCBs, particularly the more highly persistent congeners, may negatively influence testosterone levels among adolescent males. The positive relationship between p,p´-DDE and testosterone indicates that not all POPs act similarly. Citation: Schell LM, Gallo MV, Deane GD, Nelder KR, DeCaprio AP, Jacobs A; Akwesasne Task Force on the Environment. 2014. Relationships of polychlorinated biphenyls and dichlorodiphenyldichloroethylene (p,p´-DDE) with testosterone levels in adolescent males. Environ Health Perspect 122:304–309; http://dx.doi.org/10.1289/ehp.1205984 PMID:24398050

Serum concentrations of polychlorinated dibenzo-p-dioxins among ceramicists.

PubMed

Demond, Avery; Jiang, Xiaohui; Broadwater, Kendra; Meeker, John; Luksemburg, William; Maier, Martha; Garabrant, David; Franzblau, Alfred

2015-01-01

Polychlorinated dibenzo-p-dioxins (PCDDs) occur naturally in ball clay at elevated concentrations. Thus, persons who habitually work with clay may be at risk for exposure to PCDDs. An earlier case report provided some evidence of elevated PCDD levels in serum for long-term hobby ceramicists; however, no previous study has measured serum dioxin concentrations among ceramicists. This study measured PCDD serum levels for 27 individuals involved in ceramics making. The average residual, defined as the average of the [log measured serum lipid concentration – log background serum lipid concentration], was calculated and then tested to determine whether it was significantly different from zero. The p-values for the average residuals indicated that the serum lipid concentrations for several PCDD congeners were elevated relative to background. The number of significant residuals increased dramatically if the background concentrations were adjusted to account for the fact that they were not contemporaneous with the measurements for the ceramicists. The ratio of the 1,2,3,6,7,8-HxCDD concentration to the 1,2,3,7,8,9-HxCDD concentration was greater than 1.0, unlike in ball clay, suggesting that although long-term working with ball clay elevates the PCDD levels in serum somewhat, it is not the predominant source of the PCDD body burden for ceramicists.

Investigation of PAH Biomarkers in the Urine of Workers Exposed to Hot Asphalt

PubMed Central

Sobus, Jon R.; Mcclean, Michael D.; Herrick, Robert F.; Waidyanatha, Suramya; Onyemauwa, Frank; Kupper, Lawrence L.; Rappaport, Stephen M.

2009-01-01

Airborne emissions from hot asphalt contain mixtures of polycyclic aromatic hydrocarbons (PAHs), including several carcinogens. We investigated urinary biomarkers of three PAHs, namely naphthalene (Nap), phenanthrene (Phe), and pyrene (Pyr) in 20 road-paving workers exposed to hot asphalt and in 6 road milling workers who were not using hot asphalt (reference group). Our analysis included baseline urine samples as well as postshift, bedtime, and morning samples collected over three consecutive days. We measured unmetabolized Nap (U-Nap) and Phe (U-Phe) as well as the monohydroxylated metabolites of Nap (OH-Nap), Phe (OH-Phe), and Pyr (OH-Pyr) in each urine sample. In baseline samples, no significant differences in biomarker levels were observed between pavers and millers, suggesting similar background exposures. In postshift, bedtime, and morning urine samples, the high pairwise correlations observed between levels of all biomarkers suggest common exposure sources. Among pavers, levels of all biomarkers were significantly elevated in postshift samples, indicating rapid uptake and elimination of PAHs following exposure to hot asphalt (biomarker levels were not elevated among millers). Results from linear mixed-effects models of levels of U-Nap, U-Phe, OH-Phe, and OH-Pyr across pavers showed significant effects of work assignments with roller operators having lower biomarker levels than the other workers. However, no work-related effect was observed for levels of OH-Nap, apparently due to the influence of cigarette smoking. Biological half-lives, estimated from regression coefficients for time among pavers, were 8 h for U-Phe, 10 h for U-Nap, 13 h for OH-Phe and OH-Pyr, and 26 h for OH-Nap. These results support the use of U-Nap, U-Phe, OH-Phe, and OH-Pyr, but probably not OH-Nap, as short-term biomarkers of exposure to PAHs emanating from hot asphalt. PMID:19602500