Effect of endocrine disruptors on male reproduction in humans: why the evidence is still lacking?

PubMed

Bliatka, D; Lymperi, S; Mastorakos, G; Goulis, D G

2017-05-01

The so-called "endocrine disruption hypothesis" suggests that exposures to endocrine disruption (EDs) during fetal, neonatal and adult life may interfere with the development of reproductive organs and alter semen quality and reproductive hormone production. Even though animal studies provide substantial evidence of adverse effects of EDs on male reproductive system, epidemiological studies in humans arrive at conflicting results. The aim of the present study was to systematically review the literature to locate methodological characteristics of the studies that struggle the formation of an association between EDs and human male reproduction. Such characteristics include: (i) definition of the exposed and the non-exposed population, (ii) age, (iii) insufficient control for confounders, (iv) ED assay and threshold, (v) time parameters of ED exposure, and (vi) study outcomes. Additional issues are: (i) the late effect of an early exposure, (ii) the multiple exposure effect, and (iii) the fact the same ED may exhibit different modes of action. Unfortunately, the nature of the field precludes the conduction of randomized-controlled trials, which could result to etiological associations between EDs and human male reproduction. Consequently, there is a great need to conduct well-designed studies of case-control or cohort type to evaluate EDs effects on human male reproductive health, and apply possible measures that could limit dangerous exposures. © 2017 American Society of Andrology and European Academy of Andrology.

Chlorpyrifos PBPK/PD model for multiple routes of exposure.

PubMed

Poet, Torka S; Timchalk, Charles; Hotchkiss, Jon A; Bartels, Michael J

2014-10-01

1. Chlorpyrifos (CPF) is an important pesticide used to control crop insects. Human Exposures to CPF will occur primarily through oral exposure to residues on foods. A physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model has been developed that describes the relationship between oral, dermal and inhalation doses of CPF and key events in the pathway for cholinergic effects. The model was built on a prior oral model that addressed age-related changes in metabolism and physiology. This multi-route model was developed in rats and humans to validate all scenarios in a parallelogram design. 2. Critical biological effects from CPF exposure require metabolic activation to CPF oxon, and small amounts of metabolism in tissues will potentially have a great effect on pharmacokinetics and pharmacodynamic outcomes. Metabolism (bioactivation and detoxification) was therefore added in diaphragm, brain, lung and skin compartments. Pharmacokinetic data are available for controlled human exposures via the oral and dermal routes and from oral and inhalation studies in rats. The validated model was then used to determine relative dermal versus inhalation uptake from human volunteers exposed to CPF in an indoor scenario.

Impact of nanoparticles on human and environment: review of toxicity factors, exposures, control strategies, and future prospects.

PubMed

Sajid, Muhammad; Ilyas, Muhammad; Basheer, Chanbasha; Tariq, Madiha; Daud, Muhammad; Baig, Nadeem; Shehzad, Farrukh

2015-03-01

Nanotechnology has revolutionized the world through introduction of a unique class of materials and consumer products in many arenas. It has led to production of innovative materials and devices. Despite of their unique advantages and applications in domestic and industrial sectors, use of materials with dimensions in nanometers has raised the issue of safety for workers, consumers, and human environment. Because of their small size and other unique characteristics, nanoparticles have ability to harm human and wildlife by interacting through various mechanisms. We have reviewed the characteristics of nanoparticles which form the basis of their toxicity. This paper also reviews possible routes of exposure of nanoparticles to human body. Dermal contact, inhalation, and ingestion have been discussed in detail. As very limited data is available for long-term human exposures, there is a pressing need to develop the methods which can determine short and long-term effects of nanoparticles on human and environment. We also discuss in brief the strategies which can help to control human exposures to toxic nanoparticles. We have outlined the current status of toxicological studies dealing with nanoparticles, accomplishments, weaknesses, and future challenges.

Evaluation of cosmetic product exposures reported to the Milan Poison Control Centre, Italy from 2005 to 2010.

PubMed

Ruggiero, Simona; Moro, Paola Angela; Davanzo, Franca; Capuano, Annalisa; Rossi, Francesco; Sautebin, Lidia

2012-12-01

To the average consumer, "cosmetics" are not considered to cause damage to human health under normal conditions of use. Thus, cosmetic "safety" does not require any particular attention to the possibility that cosmetics may result in a toxic exposure, especially for children. Poison Control Centres (PCCs) provide specialized and rapid information for consumers and health professionals to ensure management of events related to the exposures to different agents, including Cosmetics. Poison Control Centres also represent a unique source of information to investigate the frequency and type of exposures to cosmetic and the related risks. An analysis of cases concerning human exposures to cosmetics collected from 2005 to 2010 by the PCC at the Ospedale Niguarda Ca' Granda (Milan, Italy) was performed. During this period, 11 322 human exposure cases related to cosmetics were collected accounting for 4.5% of the total human clinical cases. Almost, all the requests for assistance came from consumers (53%) and hospitals (40%). The most frequently reported site of exposure was the consumer's own residence (94%). The exposures mainly involved children younger than 4 years (77%). No difference in gender distribution was observed (female 49%, male 51%). Almost, all of the exposures were unintentional (94%). Intentional exposures, mainly related to suicide attempts and accounted for 6% of cases involving persons aged more than 12 years. Personal hygiene products (30%), perfumes and hair care products (excluding hair dyes) (both 13%) were the most frequently involved categories. Symptoms were present only in 26% of the exposures and were mostly gastrointestinal (46%). Most of the cases were managed at home (43%) whereas hospital intervention was required in 38%. Since the exposure frequency seems more likely to reflect product availability and accessibility to ingestors, our results call for closer attention to this type of hazard, especially for children younger than 4 years of age.

Mass Spectrometric Analyses of Phosphatidylcholines in Alkali-Exposed Corneal Tissue

PubMed Central

Crane, Ashley M.; Hua, Hong-Uyen; Coggin, Andrew D.; Gugiu, Bogdan G.; Lam, Byron L.; Bhattacharya, Sanjoy K.

2012-01-01

Purpose. The aims were to determine whether exposure to sodium hydroxide results in predictable changes in phosphatidylcholine (PC) in corneal tissue and if PC profile changes correlate to exposure duration. PCs are major components of the cell membrane lipid bilayer and are often involved in biological processes such as signaling. Methods. Enucleated porcine (n = 140) and cadaver human eyes (n = 20) were exposed to water (control) and 11 M NaOH. The corneas were excised and lipids were extracted using the Bligh and Dyer method with suitable modifications. Class-specific lipid identification was carried out using a ratiometric lipid standard on a TSQ Quantum Access Max mass spectrometer. Protein amounts were determined using Bradford assays. Results. Control and alkali-treated corneas showed reproducible PC spectra for both porcine and human corneas. Over 200 PCs were identified for human and porcine control and each experimental time point. Several PC species (m/z values) consequent upon alkali exposure could not be ascribed to a recorded PC species. Control and treated groups showed 41 and 29 common species among them for porcine and human corneas, respectively. The unique PC species peaked at 12 minutes and at 30 minutes for human and porcine corneas followed by a decline consistent with an interplay of alkali penetration and hydrolyses at various time points. Conclusions. Alkali exposure dramatically changes the PC profile of cornea. Our data are consistent with penetration and hydrolysis as stochastic contributors to changes in PCs due to exposure to alkali for a finite duration and amount. PMID:22956606

ELISA measurement of stachylysin in serum to quantify human exposures to the indoor mold Stachybotrys chartarum.

PubMed

Van Emon, Jeanette M; Reed, Allan W; Yike, Iwona; Vesper, Stephen J

2003-06-01

The goal of this research was to develop a measurable indicator of human exposure to Stachyborys chartarum. Antibodies were produced against the hemolytic agent stachylysin obtained from the mold S. chartarum. These antibodies were used to develop two enzyme-linked immunosorbent assay methods for the analysis of stachylysin in human and rat sera and environmental samples. Stachylysin was measured in rat pups that received nasal instillations of S. chartarum conidia but not in control rat serum. Stachylysin in the serum of five human adults exposed to S. chartarum in water-damaged environments was 371 ng/mL but none was detected in the control serum. Stachylysin was also quantified in spore, wallboard, mycelial, and dust samples. The measurement of stachylysin may be a useful indicator in assessing human exposure to S. chartarum and in determining the presence of this indoor mold.

A Preliminary Assessment of the Benefits of Reducing Formaldehyde Exposures (1984)

EPA Pesticide Factsheets

The report reviews a variety of regulatory responses that EPA might consider in developing regulatory strategies for controlling human exposures under the Toxic Substance Control Act and previewed issues that may arise in a regulatory impact analysis.

DEPOSITION DISTRIBUTION OF NANO AND ULTRAFINE PARTICLES IN HUMAN LUNGS DURING CONTROLLED MOUTH BREATHING

EPA Science Inventory

Nano and ultrafine particles are abundant in the atmosphere and the level of human exposure to these tiny particles is expected to increase markedly as industrial activities increase manufacturing nano-sized materials. Exposure-dose relationships and site-specific internal dose a...

Self-Control and Impulsiveness in Nondieting Adult Human Females: Effects of Visual Food Cues and Food Deprivation

ERIC Educational Resources Information Center

Forzano, Lori-Ann B.; Chelonis, John J.; Casey, Caitlin; Forward, Marion; Stachowiak, Jacqueline A.; Wood, Jennifer

2010-01-01

Self-control can be defined as the choice of a larger, more delayed reinforcer over a smaller, less delayed reinforcer, and impulsiveness as the opposite. Previous research suggests that exposure to visual food cues affects adult humans' self-control. Previous research also suggests that food deprivation decreases adult humans' self-control. The…

Rare earth elements in human and animal health: State of art and research priorities.

PubMed

Pagano, Giovanni; Aliberti, Francesco; Guida, Marco; Oral, Rahime; Siciliano, Antonietta; Trifuoggi, Marco; Tommasi, Franca

2015-10-01

A number of applications have been developed using rare earth elements (REE), implying several human exposures and raising unsolved questions as to REE-associated health effects. A MedLine survey was retrieved from early reports (1980s) up to June 2015, focused on human and animal exposures to REE. Literature from animal models was selected focusing on REE-associated health effects. Some REE occupational exposures, in jobs such as glass polishers, photoengravers and movie projectionists showed a few case reports on health effects affecting the respiratory system. No case-control or cohort studies of occupational REE exposures were retrieved. Environmental exposures have been biomonitored in populations residing in REE mining areas, showing REE accumulation. The case for a iatrogenic REE exposure was raised by the use of gadolinium-based contrast agents for nuclear magnetic resonance. Animal toxicity studies have shown REE toxicity, affecting a number of endpoints in liver, lungs and blood. On the other hand, the use of REE as feed additives in livestock is referred as a safe and promising device in zootechnical activities, possibly suggesting a hormetic effect both known for REE and for other xenobiotics. Thus, investigations on long-term exposures and observations are warranted. The state of art provides a limited definition of the health effects in occupationally or environmentally REE-exposed human populations. Research priorities should be addressed to case-control or cohort studies of REE-exposed humans and to life-long animal experiments. Copyright © 2015 Elsevier Inc. All rights reserved.

[Effects of rare earth compounds on human peripheral mononuclear cell telomerase and apoptosis].

PubMed

Yu, Li; Dai, Yu-Cheng; Yuan, Zhao-Kang; Li, Jie

2004-07-01

To study the effects of rare earth exposure on human telomerase and apoptosis of human peripheral mononuclear cells (PBMNs). Rare earth mine lot in Xunwu county, the biggest ion absorptive rare earth mine lot of China, was selected as the study site. Another village of Xunwu county, with comparable geological structure and social environment was selected as the control site. Thirty healthy adults were randomly selected from the study site as exposure group and another 30 healthy adults randomly selected from the control site as control group. The blood content of 15 rare earth elements, including La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y, were determined by inductive coupled plasma-source mass spectrometry (ICP-MS). The total contents of rare earth elements in the blood were calculated. The TRAP and FCM assays were carried out to analyse the telomerase and apoptosis of human PBMNCs respectively. In the exposure group, the concentration of La, Ce, Dy and Y were significantly higher (P<0.001), and Pr, Nd, Sm, Gd and Yb were higher than those in the control group (P<0.05). The total content of rare earth in the blood of exposure group showed significant difference compared with control group (P<0.001). Telomerase activity in PBMNs of the exposure group was higher than that in the control group (P<0.05); there were 11 adults in the exposure group (30 adults) and 5 adults in control group (30 adults) showed positive telomerase activity. The average age of the exposure group was (38.69 +/- 8.02) years-old, while the control group was (40.45 +/- 9.02) years-old (P >0.05). It was found that there was a significant relationship between telomerase activity and the total content of rare earth elements (P <0.01). 3. The proportion of apoptosis was not different between the two groups (P >0.05), but the cells in the S-phase and G2-M phase were increased (P <0.01) in the exposed group. The telomerase activity of PBMNs in the rare earth elements exposed group was higher than that of the control group, and there is no effect on apoptotic rate of PBMNs, but may promote the diploid DNA replication, and increase the percentage of G2/M and S phase cells.

Exposure to Stress: Occupational Hazards in Hospitals

MedlinePlus

EXPOSURE TO STRESS Occupational Hazards in Hospitals DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention National Institute for Occupational Safety and Health Exposure to Stress Occupational Hazards in Hospitals DEPARTMENT OF HEALTH AND ...

Pesticide Ingredients

Science.gov Websites

; Environment Human Health Animal Health Safe Use Practices Food Safety Environment Air Water Soil Wildlife Ingredients Low-Risk Pesticides Organic Pesticide Ingredients Pesticide Incidents Human Exposure Pet Exposure Fact Sheets Types of Pesticides Pest Control Information Pesticide Health and Safety Information

CONTROLLED, SHORT-TERM DERMAL AND INHALATION EXPOSURE TO CHLOROFORM

EPA Science Inventory

Studies were conducted to determine the uptake by humans of chloroform as a result of controlled short-term dermal and inhalation exposures. The approach used continuous real-time breath analysis to determine exhaled-breath profiles and evaluate chloroform kinetics in the huma...

Potential human exposures to neonicotinoid insecticides: A review.

PubMed

Zhang, Q; Li, Z; Chang, C H; Lou, J L; Zhao, M R; Lu, C

2018-05-01

Due to their systemic character and high efficacy to insect controls, neonicotinoid insecticides (neonics) have been widely used in global agriculture since its introduction in early 1990. Recent studies have indicated that neonics may be ubiquitous, have longer biological half-lives in the environment once applied, and therefore implicitly suggested the increasing probability for human exposure to neonics. Despite of neonics' persistent characters and widespread uses, scientific literature in regard of pathways in which human exposure could occur is relatively meager. In this review, we summarized results from peer-reviewed articles published prior to 2017 that address potential human exposures through ingestion and inhalation, as well as results from human biomonitoring studies. In addition, we proposed the use of relative potency factor approach in order to facilitate the assessment of concurrent exposure to a mixture of neonics with similar chemical structures and toxicological endpoints. We believe that the scientific information that we presented in this review will aid to future assessment of total neonic exposure and subsequently human health risk characterization. Copyright © 2018 Elsevier Ltd. All rights reserved.

BIOACCUMULATION OF POPS IN FISH AND ESTIMATION OF HUMAN DIETARY EXPOSURE AND DOSE

EPA Science Inventory

The risk assessment process is fundamental in understanding and controlling environmental health risks. Risk assessment includes four steps: hazard identification, dose-response assessment, exposure assessment, and risk characterization. Exposure assessments seek to characteriz...

EPA perspective - exposure and effects prediction and monitoring

EPA Science Inventory

Risk-based decisions for environmental chemicals often rely on estimates of human exposure and biological response. Biomarkers have proven a useful empirical tool for evaluating exposure and hazard predictions. In the United States, the Centers for Disease Control and Preventio...

ZINC-DEFICIENCY ENHANCES PRO-INFLAMMATORY RESPONSES AFTER OZONE EXPOSURE

EPA Science Inventory

Epidemiological and controlled exposure studies have demonstrated that humans are differentially susceptible to adverse health effects induced by exposure to ozone. Serum analysis of vitamins and trace elements have shown that the elderly (people >65 years) are deficient in sever...

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

Serum vitamin D levels are not altered after controlled diesel exhaust exposures in healthy human subjects

EPA Science Inventory

Past research has suggested that exposure to urban air pollution may be associated with vitamin D deficiency in human populations. Vitamin D is widely known for its importance in bone growth/remodeling, muscle metabolism, and its ability to promote calcium absorption in the gut; ...

Reconstruction of Exposure to m-Xylene from Human Biomonitoring Data Using PBPK Modelling, Bayesian Inference, and Markov Chain Monte Carlo Simulation

PubMed Central

McNally, Kevin; Cotton, Richard; Cocker, John; Jones, Kate; Bartels, Mike; Rick, David; Price, Paul; Loizou, George

2012-01-01

There are numerous biomonitoring programs, both recent and ongoing, to evaluate environmental exposure of humans to chemicals. Due to the lack of exposure and kinetic data, the correlation of biomarker levels with exposure concentrations leads to difficulty in utilizing biomonitoring data for biological guidance values. Exposure reconstruction or reverse dosimetry is the retrospective interpretation of external exposure consistent with biomonitoring data. We investigated the integration of physiologically based pharmacokinetic modelling, global sensitivity analysis, Bayesian inference, and Markov chain Monte Carlo simulation to obtain a population estimate of inhalation exposure to m-xylene. We used exhaled breath and venous blood m-xylene and urinary 3-methylhippuric acid measurements from a controlled human volunteer study in order to evaluate the ability of our computational framework to predict known inhalation exposures. We also investigated the importance of model structure and dimensionality with respect to its ability to reconstruct exposure. PMID:22719759

Nanoparticles, human health hazard and regulation

PubMed Central

Seaton, Anthony; Tran, Lang; Aitken, Robert; Donaldson, Kenneth

2010-01-01

New developments in technology usually entail some hazard as well as advantage to a society. Hazard of a material translates into risk by exposure of humans and/or their environment to the agent in question, and risk is reduced by control of exposure, usually guided by regulation based on understanding of the mechanisms of harm. We illustrate risks relating to the causation of diseases associated with exposure to aerosols of combustion particles and asbestos, leading to paradigms of particle toxicity, and discuss analogies with potential exposure to manufactured nanoparticles (NPs). We review the current understanding of the hazard of NPs derived from the new science of nanotoxicology and the limited research to date into human exposure to these particles. We identify gaps in knowledge relating to the properties of NPs that might determine toxicity and in understanding the most appropriate ways both to measure this in the laboratory and to assess it in the workplace. Nevertheless, we point out that physical principles governing the behaviour of such particles allow determination of practical methods of protecting those potentially exposed. Finally, we discuss the early steps towards regulation and the difficulties facing regulators in controlling potentially harmful exposures in the absence of sufficient scientific evidence. PMID:19726441

Altered spatial learning and delay discounting in a rat model of human third trimester binge ethanol exposure

PubMed Central

Bañuelos, Cristina; Gilbert, Ryan J.; Montgomery, Karienn S.; Fincher, Annette S.; Wang, Haiying; Frye, Gerald D.; Setlow, Barry; Bizon, Jennifer L.

2012-01-01

Ethanol exposure during perinatal development can cause cognitive abnormalities including difficulties in learning, attention, and memory, as well as heightened impulsivity. The purpose of this study was to assess performance in spatial learning and impulsive choice tasks in rats subjected to an intragastric intubation model of binge ethanol exposure during human third trimester-equivalent brain development. Male and female Sprague–Dawley rat pups were intubated with ethanol (5.25 g/kg/day) on postnatal days 4–9. At adolescence (between postnatal days 35–38), these rats and sham intubated within-litter controls were trained in both spatial and cued versions of the Morris water maze. A subset of the male rats was subsequently tested on a delay-discounting task to assess impulsive choice. Ethanol-exposed rats were spatially impaired relative to controls, but performed comparably to controls on the cued version of the water maze. Ethanol-exposed rats also showed greater preference for large delayed rewards on the delay discounting task, but no evidence for altered reward sensitivity or perseverative behavior. These data demonstrate that early postnatal intermittent binge-like ethanol exposure has prolonged, detrimental, but selective effects on cognition, suggesting that even relatively brief ethanol exposure late in human pregnancy can be deleterious for cognitive function. PMID:22129556

High Incidence of Human Rabies Exposure in Northwestern Tigray, Ethiopia: A Four-Year Retrospective Study

PubMed Central

Teklu, Gebreyohans Gebru; Hailu, Teweldemedhn Gebretinsae; Eshetu, Gebremedhin Romha

2017-01-01

Background Rabies is a fatal zoonotic disease that has been known in Ethiopia for centuries in society as “Mad Dog Disease”. It is an important disease with veterinary and public health significance in the North western zone of Tigray where previous studies have not been conducted. Frequent occurrence of outbreaks in the area led the researchers to carry out a four year retrospective study to estimate the incidence of human rabies exposure in Northwestern Tigray, Ethiopia. Methodology A referent study was conducted on human rabies exposure cases recorded from 2012 to 2015 at Suhul hospital, Shire Endaselase, Northwestern Tigray, Ethiopia. Exposure cases included in this research constituted victims bitten by unprovoked dogs and who received post exposure prophylaxis (PEP) at the hospital. Two thousand one hundred eighty human rabies exposure cases retrieved from the rabies case database were included in this study. Principal findings The majority of the exposed cases were males (1363/2180, 63%). Age wise, the most exposed age group was ≥15 years in all the study years: 166 (58%), 335 (65%), 492 (66%) and 394 (63%) in 2012, 2013, 2014 and 2015, respectively. Similarly, exposure cases for human rabies increased with age in both males and females across the study years. The incidence of human rabies exposure cases calculated per 100,000 populations was 35.8, 63.0, 89.8 and 73.1 in 2012, 2013, 2014 and 2015, respectively. Binary logistic regression analysis revealed that being male was a risk for human rabies exposure in all the study years. Conclusion The study discovered the highest annual human rabies exposure incidence in Ethiopia. This suggests an urgent need for synergistic efforts of human and animal health sectors to implement prevention and control strategies in this area. PMID:28060935

Diesel exposure suppresses natural killer cell function and resolution of eosinophil inflammation: a randmonized controlled trial of exposure in allergic rhinitics

EPA Science Inventory

Exposure to diesel exhaust (DE) is known to exacerbate allergic inflammation, including virus induced eosinophil activation in laboratory animals. We have previously shown that in human volunteers with allergic rhinitis a short-term exposure to DE prior to infection with the live...

TOWARD COST-BENEFIT ANALYSIS OF ACUTE BEHAVIORAL EFFECTS OF TOLUENE IN HUMANS

EPA Science Inventory

There is increasing interest in being able to express the consequences of exposure to potentially toxic compounds in monetary terms in order to evaluate potential cost-benefit relationships of controlling exposure. Behavioral effects of acute toluene exposure could be subjected ...

77 FR 76490 - Determination Concerning a Petition to Add a Class of Employees to the Special Exposure Cohort

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-28

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Determination Concerning a Petition to Add a Class of... (NIOSH), Centers for Disease Control and Prevention, Department of Health and Human Services (HHS... employees from the Mound Plant in Miamisburg, Ohio, to the Special Exposure Cohort (SEC) under the Energy...

78 FR 70949 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-27

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for... (NIOSH), Centers for Disease Control and Prevention, Department of Health and Human Services (HHS... class of employees from the Pantex Plant in Amarillo, Texas, as an addition to the Special Exposure...

A systematic review of the human body burden of e-waste exposure in China.

PubMed

Song, Qingbin; Li, Jinhui

2014-07-01

As China is one of the countries facing the most serious pollution and human exposure effects of e-waste in the world, much of the population there is exposed to potentially hazardous substances due to informal e-waste recycling processes. This report reviews recent studies on human exposure to e-waste in China, with particular focus on exposure routes (e.g. dietary intake, inhalation, and soil/dust ingestion) and human body burden markers (e.g. placenta, umbilical cord blood, breast milk, blood, hair, and urine) and assesses the evidence for the association between such e-waste exposure and the human body burden in China. The results suggest that residents in the e-waste exposure areas, located mainly in the three traditional e-waste recycling sites (Taizhou, Guiyu, and Qingyuan), are faced with a potential higher daily intake of these pollutants than residents in the control areas, especially via food ingestion. Moreover, pollutants (PBBs, PBDEs, PCBs, PCDD/Fs, and heavy metals) from the e-waste recycling processes were all detectable in the tissue samples at high levels, showing that they had entered residents' bodies through the environment and dietary exposure. Children and neonates are the groups most sensitive to the human body effects of e-waste exposure. We also recorded plausible outcomes associated with exposure to e-waste, including 7 types of human body burden. Although the data suggest that exposure to e-waste is harmful to health, better designed epidemiological investigations in vulnerable populations, especially neonates and children, are needed to confirm these associations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Rare earth elements in human and animal health: State of art and research priorities

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

Pagano, Giovanni, E-mail: gbpagano@tin.it; Aliberti, Francesco; Guida, Marco

Background: A number of applications have been developed using rare earth elements (REE), implying several human exposures and raising unsolved questions as to REE-associated health effects. Methods: A MedLine survey was retrieved from early reports (1980s) up to June 2015, focused on human and animal exposures to REE. Literature from animal models was selected focusing on REE-associated health effects. Results: Some REE occupational exposures, in jobs such as glass polishers, photoengravers and movie projectionists showed a few case reports on health effects affecting the respiratory system. No case-control or cohort studies of occupational REE exposures were retrieved. Environmental exposures havemore » been biomonitored in populations residing in REE mining areas, showing REE accumulation. The case for a iatrogenic REE exposure was raised by the use of gadolinium-based contrast agents for nuclear magnetic resonance. Animal toxicity studies have shown REE toxicity, affecting a number of endpoints in liver, lungs and blood. On the other hand, the use of REE as feed additives in livestock is referred as a safe and promising device in zootechnical activities, possibly suggesting a hormetic effect both known for REE and for other xenobiotics. Thus, investigations on long-term exposures and observations are warranted. Conclusion: The state of art provides a limited definition of the health effects in occupationally or environmentally REE-exposed human populations. Research priorities should be addressed to case-control or cohort studies of REE-exposed humans and to life-long animal experiments. - Highlights: • An extensive number of activities have been developed utilizing rare earth elements (REE). • The literature of REE-associated health effects in humans, and on animal studies is reviewed. • The main literature gaps are discussed, in epidemiological and in animal studies. • Prospects studies are suggested, aimed at evaluating long-term effects of REE exposures. • The relevance of REE-related hormesis, speciation and acidic pollution are discussed.« less

Inferior retinal light exposure is more effective than superior retinal exposure in suppressing melatonin in humans

NASA Technical Reports Server (NTRS)

Glickman, Gena; Hanifin, John P.; Rollag, Mark D.; Wang, Jenny; Cooper, Howard; Brainard, George C.

2003-01-01

Illumination of different areas of the human retina elicits differences in acute light-induced suppression of melatonin. The aim of this study was to compare changes in plasma melatonin levels when light exposures of equal illuminance and equal photon dose were administered to superior, inferior, and full retinal fields. Nine healthy subjects participated in the study. Plexiglass eye shields were modified to permit selective exposure of the superior and inferior halves of the retinas of each subject. The Humphrey Visual Field Analyzer was used both to confirm intact full visual fields and to quantify exposure of upper and lower visual fields. On study nights, eyes were dilated, and subjects were exposed to patternless white light for 90 min between 0200 and 0330 under five conditions: (1) full retinal exposure at 200 lux, (2) full retinal exposure at 100 lux, (3) inferior retinal exposure at 200 lux, (4) superior retinal exposure at 200 lux, and (5) a dark-exposed control. Plasma melatonin levels were determined by radioimmunoassay. ANOVA demonstrated a significant effect of exposure condition (F = 5.91, p < 0.005). Post hoc Fisher PLSD tests showed significant (p < 0.05) melatonin suppression of both full retinal exposures as well as the inferior retinal exposure; however, superior retinal exposure was significantly less effective in suppressing melatonin. Furthermore, suppression with superior retinal exposure was not significantly different from that of the dark control condition. The results indicate that the inferior retina contributes more to the light-induced suppression of melatonin than the superior retina at the photon dosages tested in this study. Findings suggest a greater sensitivity or denser distribution of photoreceptors in the inferior retina are involved in light detection for the retinohypothalamic tract of humans.

Twenty Four-Hour Exposure to a 0.12 THz Electromagnetic Field Does Not Affect the Genotoxicity, Morphological Changes, or Expression of Heat Shock Protein in HCE-T Cells.

PubMed

Koyama, Shin; Narita, Eijiro; Shimizu, Yoko; Shiina, Takeo; Taki, Masao; Shinohara, Naoki; Miyakoshi, Junji

2016-08-05

To investigate the cellular effects of terahertz (THz) exposure, human corneal epithelial (HCE-T) cells derived from human eye were exposed to 0.12 THz radiation at 5 mW/cm² for 24 h, then the genotoxicity, morphological changes, and heat shock protein (Hsp) expression of the cells were examined. There was no statistically significant increase in the micronucleus (MN) frequency of cells exposed to 0.12 THz radiation compared with sham-exposed controls and incubator controls, whereas the MN frequency of cells treated with bleomycin for 1 h (positive control) did increase significantly. Similarly, there were no significant morphological changes in cells exposed to 0.12 THz radiation compared to sham-exposed controls and incubator controls, and Hsp expression (Hsp27, Hsp70, and Hsp90α) was also not significantly different between the three treatments. These results indicate that exposure to 0.12 THz radiation using the present conditions appears to have no or very little effect on MN formation, morphological changes, and Hsp expression in cells derived from human eye.

Multifactorial analysis of human blood cell responses to clinical total body irradiation

NASA Technical Reports Server (NTRS)

Yuhas, J. M.; Stokes, T. R.; Lushbaugh, C. C.

1972-01-01

Multiple regression analysis techniques are used to study the effects of therapeutic radiation exposure, number of fractions, and time on such quantal responses as tumor control and skin injury. The potential of these methods for the analysis of human blood cell responses is demonstrated and estimates are given of the effects of total amount of exposure and time of protraction in determining the minimum white blood cell concentration observed after exposure of patients from four disease groups.

Influence of linearly polarized near-infrared irradiation on deformability of human stored erythrocytes.

PubMed

Yokoyama, Kozo; Sugiyama, Kazuna

2003-02-01

To investigate the influence of linearly polarized near-infrared irradiation using the Super Lizer trade mark on deformability of human erythrocytes. Not only low-powered laser but also linearly polarized near-infrared beams have some biostimulation effects on various tissues. There were some reports of erythrocyte deformability improved by low-powered He-Ne laser irradiation. Human erythrocyte samples stored for three weeks were adjusted to 30% hematocrit. Erythrocyte deformability presented as the filter filtration rate was measured. There was no difference of the filter filtration rate between control group without irradiation and the group of 125 mJ/cm(2) exposure level at a wavelength of 830 nm. However, the groups of 625 and 1,250 mJ/cm(2) exposure levels at a wavelength of 830 nm showed higher filter filtration rates compared to the control group. Linearly polarized near-infrared irradiation in a range of 625-1,250 mJ/cm(2) exposure level at a wavelength of 830 nm improved deformability of human stored erythrocytes.

Human rabies in Tianjin, China.

PubMed

Montgomery, J P; Zhang, Y; Wells, E V; Liu, Y; Clayton, J L; Wang, X; Boulton, M L

2012-12-01

Human rabies has recently re-emerged as a significant public health threat in Tianjin, China. Using surveillance data compiled by the Tianjin Centers for Disease Control and Prevention, we describe 60 cases of human rabies reported from 2005 to 2011 in the municipality of Tianjin, China. All 60 cases of human rabies resulted in death. Cases were primarily male (80%), middle aged (mean 40.6 years), and exposed to rabies in a rural setting (82%). Most exposures were associated with dog bites (93%) and no animal had a history of rabies vaccination; no cases were laboratory confirmed. Fifteen percent of patients sought medical attention for their wound, and none received a complete regimen of WHO-recommended post-exposure prophylaxis (PEP). These findings suggest the need for China's public health authority to improve animal rabies surveillance and control strategies through laboratory case confirmation, more rapid response to potential exposures with provision of appropriate PEP, and education to the public and to health care providers on identifying and reducing rabies risk.

Biomarkers of Dose and Effect of inhaled ozone in resting versus exercising human subjects: comparison with resting rats

EPA Science Inventory

Background: Human controlled exposure studies have generally focused on subjects exposed to ozone (O3) while exercising while exposures in rats have been done at rest. We exposed resting subjects to labeled O3 (18O3, 0.4 ppm, for 2 hr) and compared O3 dose and effects with our...

EXPOSURE RECONSTRUCTION FOR REDUCING UNCERTAINTY IN RISK ASSESSMENT: EXAMPLE USING MTBE BIOMARKERS AND SIMPLE PHARMACOKINETIC MODEL

EPA Science Inventory

Adverse health risks from environmental agents are generally related to average (long term) exposures. We used results from a series of controlled human exposure tests and classical first order rate kinetics calculations to estimate how well spot measurements of methyl tertiary ...

CONTROLLED EXPOSURES OF HUMAN VOLUNTEERS TO DIESEL ENGINE EXHAUST: BIOMARKERS OF EXPOSURE AND HEALTH OUTCOMES

EPA Science Inventory

Combustion of diesel fuel contributes to ambient air pollutant fine particulate matter (PM) and gases. Fine PM exposure has been associated with increased mortality due to adverse cardiac events, and morbidity, such as increased hospitalization for asthma symptoms and lung infect...

Marine disposal of radioactive wastes

NASA Astrophysics Data System (ADS)

Woodhead, D. S.

1980-03-01

In a general sense, the main attraction of the marine environment as a repository for the wastes generated by human activities lies in the degree of dispersion and dilution which is readily attainable. However, the capacity of the oceans to receive wastes without unacceptable consequences is clearly finite and this is even more true of localized marine environments such as estuaries, coastal waters and semi-enclosed seas. Radionuclides have always been present in the marine environment and marine organisms and humans consuming marine foodstuffs have always been exposed, to some degree, to radiation from this source. The hazard associated with ionizing radiations is dependent upon the absorption of energy from the radiation field within some biological entity. Thus any disposal of radioactive wastes into the marine environment has consequences, the acceptability of which must be assessed in terms of the possible resultant increase in radiation exposure of human and aquatic populations. In the United Kingdom the primary consideration has been and remains the safe-guarding of public health. The control procedures are therefore designed to minimize as far as practicable the degree of human exposure within the overall limits recommended as acceptable by the International Commission on Radiological Protection. There are several approaches through which control could be exercised and the strengths and weaknesses of each are considered. In this review the detailed application of the critical path technique to the control of the discharge into the north-east Irish Sea from the fuel reprocessing plant at Windscale is given as a practical example. It will be further demonstrated that when human exposure is controlled in this way no significant risk attaches to the increased radiation exposure experienced by populations of marine organisms in the area.

Advanced medical countermeasures for radiological accidents and nuclear disasters: prevention, prophylaxis, treatment and pre- and post-exposure management.

NASA Astrophysics Data System (ADS)

Popov, Dmitri; Maliev, Slava; Jones, Jeffrey

Countermeasures against nuclear terrorism to prevent or limit the number of irradiated human population or radiation intoxications include early identification of the nuclear terrorism event and all persons which exposed by radiation, decontamination program and procedures, radiation control, and medical countermeasures which include medical diagnosis,differential diagnosis of Acute Radiation Syndromes by Immune Enzyme Assay , pre-exposure vaccination with Human Antiradiation Vaccine, post-exposure specific treatment - de-intoxication with Radiation Antidote IgG (blocking Antiradiation Antibodies). Our Advanced Medical Technology elaborated as a part of effective countermeasure include Plan of Action.Countermeasures against nuclear terrorism to prevent or limit the number of high level of lethality and severe forms of radiation illness or intoxications include A.early identification of the nuclear terrorism event and persons exposed,b. appropriate decontamination, c. radiation control, and d.medical countermeasures and medical management of ARS. Medical countermeasures, which include medical interventions such as active immuneprophylaxis with Human Antiradiation Vaccine , passive immune-prophylaxis with Antiradiation Antitoxins immune-globulins IgG , and chemoprophylaxis - post-exposure antioxidants prophylaxis and antibioticprophylaxis. Medical countermeasures with Antiradiation Vaccine should be initiated before an exposure (if individuals are identified as being at high risk for exposure)but after a confirmed exposure event Antiradiation Vaccine not effective and Antiradiation Antidot IgG must be applyed for treatment of Acute Radiation Syndromes.

Modeling spatial patterns of link-based PM2.5 emissions and subsequent human exposure in a large canadian metropolitan area

NASA Astrophysics Data System (ADS)

Requia, Weeberb J.; Dalumpines, Ron; Adams, Matthew D.; Arain, Altaf; Ferguson, Mark; Koutrakis, Petros

2017-06-01

Understanding the relationship between mobile source emissions and subsequent human exposure is crucial for emissions control. Determining this relationship over space is fundamental to improve the accuracy and precision of public policies. In this study, we evaluated the spatial patterns of link-based PM2.5 emissions and subsequent human exposure in a large Canadian metropolitan area - the Greater Toronto and Hamilton Area (GTHA). This study was performed in three stages. First, we estimated vehicle emissions using transportation models and emission simulators. Then we evaluated human exposure to PM2.5 emissions using the Intake fraction (iF) approach. Finally, we applied geostatistical methods to assess spatial patterns of vehicle emissions and subsequent human exposure based on three prospective goals: i) classification of emissions (Global Moran's I test), ii) level of emission exposure (Getis-Ord General G test), and; iii) location of emissions (Anselin Local Moran's I). Our results showed that passenger vehicles accounted for the highest total amount of PM2.5 emissions, representing 57% emissions from all vehicles. Examining only the emissions from passenger vehicles, on average, each person in the GTHA inhales 2.58 × 10-3 ppm per day. Accounting the emissions from buses and trucks, on average each person inhales 0.12 × 10-3 and 1.91 × 10-3 ppm per day, respectively. For both PM2.5 emissions and human exposure using iF approach, our analysis showed Moran's Index greater than 0 for all vehicle categories, suggesting the presence of significant clusters (p-value <0.01) in the region. Our study indicates that air pollution control policy must be developed for the whole region, because of the spatial distribution of housing and businesses centers and inter-connectivity of transportation networks across the region, where a policy cannot simply be based on a municipal or other boundaries.

Factors Shaping the Human Exposome in the Built Environment: Opportunities for Engineering Control.

PubMed

Dai, Dongjuan; Prussin, Aaron J; Marr, Linsey C; Vikesland, Peter J; Edwards, Marc A; Pruden, Amy

2017-07-18

The "exposome" is a term describing the summation of one's lifetime exposure to microbes and chemicals. Such exposures are now recognized as major drivers of human health and disease. Because humans spend ∼90% of their time indoors, the built environment exposome merits particular attention. Herein we utilize an engineering perspective to advance understanding of the factors that shape the built environment exposome and its influence on human wellness and disease, while simultaneously informing development of a framework for intentionally controlling the exposome to protect public health. Historically, engineers have been focused on controlling chemical and physical contaminants and on eradicating microbes; however, there is a growing awareness of the role of "beneficial" microbes. Here we consider the potential to selectively control the materials and chemistry of the built environment to positively influence the microbial and chemical components of the indoor exposome. Finally, we discuss research gaps that must be addressed to enable intentional engineering design, including the need to define a "healthy" built environment exposome and how to control it.

Intervention strategies for carcass disposal: pareto analysis of exposures for exotic disease outbreaks.

PubMed

Delgado, João; Longhurst, Phil; Hickman, Gordon A W; Gauntlett, Daniel M; Howson, Simon F; Irving, Phil; Hart, Alwyn; Pollard, Simon J T

2010-06-15

An enhanced methodology for the policy-level prioritization of intervention options during carcass disposal is presented. Pareto charts provide a semiquantitative analysis of opportunities for multiple exposures to human health, animal health, and the wider environment during carcass disposal; they identify critical control points for risk management and assist in waste technology assessment. Eighty percent of the total availability of more than 1300 potential exposures to human, animal, or environmental receptors is represented by 16 processes, these being dominated by on-farm collection and carcass processing, reinforcing the criticality of effective controls during early stages of animal culling and waste processing. Exposures during mass burials are dominated by ground- and surface-water exposures with noise and odor nuisance prevalent for mass pyres, consistent with U.K. experience. Pareto charts are discussed in the context of other visualization formats for policy officials and promoted as a communication tool for informing the site-specific risk assessments required during the operational phases of exotic disease outbreaks.

EFFECTS OF ACTIVATED CHARCOAL FILTRATION AND OZONATION ON HYDROCARBON AND CARBONYL LEVELS OF AMBIENT AIR USED IN CONTROLLED-EXPOSURE CHAMBER STUDIES OF AIR POLLUTANT HUMAN HEALTH EFFECTS

EPA Science Inventory

Air sampling experiments were done in 1985, 1987, and 1993 at the human-exposure chamber facility of the U.S. EPA Health Effects Research Laboratory in Chapel Hill, NC. easurements of VOC's by GC-FID and aldehyde measurements by the DNPH silica gel cartridge method were made, com...

Microstructural changes in the substantia nigra of asymptomatic agricultural workers.

PubMed

Du, Guangwei; Lewis, Mechelle M; Sterling, Nicholas W; Kong, Lan; Chen, Honglei; Mailman, Richard B; Huang, Xuemei

2014-01-01

Parkinson's disease (PD) is marked by the loss of dopamine neurons in the substantia nigra (SN). Although the exact etiology is unknown, sporadic PD is hypothesized to be a result of genetic susceptibility interacting with environmental insult. Epidemiological studies suggest that pesticide exposure is linked to higher PD risk, but there are no studies demonstrating SN changes with chronic pesticide exposure in human subjects. Thus, high resolution T2-weighted magnetic resonance imaging (MRI) and diffusion tensor (DTI) images were obtained from 12 agricultural workers with chronic pesticide exposure, 12 controls, and 12 PD subjects. Neither controls nor pesticide-exposed subjects, had any parkinsonian symptoms. Exposure history to pesticides was assessed by a structured questionnaire. DTI measures in the SN, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), were obtained for all subjects and compared among groups. Compared to controls, PD patients showed the expected significant changes in all DTI measurements in the SN. The pesticide-exposed subjects, compared to controls, had significantly lower FA values (p=0.022, after multiple comparisons correction), but no significant differences in RD, MD, or AD measures. The study is the first to demonstrate microstructural changes in the SN of human subjects with chronic pesticide exposure. The changes detected by MRI may mark "one of the hits" leading to PD, and underlie the increased risk of PD in pesticide users found in epidemiological studies. Further human studies assisted by these imaging markers may be useful in understanding the etiology of PD. Copyright © 2013 Elsevier Inc. All rights reserved.

THE TIME-COURSE AND SENSITIVITY OF MUCONIC ACID AS A BIOMARKER FOR HUMAN ENVIRONMENTAL EXPOSURE TO BENZENE

EPA Science Inventory

Preliminary results are presented that show the effect of an increased benzene exposure on the urinary elimination of trans,trans-muconic acid (MA) for an adult male. These results were generated from a controlled exposure experiment where by an individual was exposed to benzene ...

Short-term ozone exposure and asthma severity: Weight-of-evidence analysis.

PubMed

Goodman, Julie E; Zu, Ke; Loftus, Christine T; Lynch, Heather N; Prueitt, Robyn L; Mohar, Isaac; Shubin, Sara Pacheco; Sax, Sonja N

2018-01-01

To determine whether evidence indicates that short-term exposure to ambient concentrations of ozone in the United States can affect asthma severity, we systematically reviewed published controlled human exposure, epidemiology, and animal toxicity studies. The strongest evidence for a potential causal relationship came from epidemiology studies reporting increased emergency department visits and hospital admissions for asthma following elevated ambient ozone concentrations. However, while controlled exposure studies reported lung function decrements and increased asthma symptoms following high ozone exposures 160-400 parts per billion [ppb]), epidemiology studies evaluating similar outcomes reported less consistent results. Animal studies showed changes in pulmonary function at high ozone concentrations (> 500ppb), although there is substantial uncertainty regarding the relevance of these animal models to human asthma. Taken together, the weight of evidence indicates that there is at least an equal likelihood that either explanation is true, i.e., the strength of the evidence for a causal relationship between short-term exposure to ambient ozone concentrations and asthma severity is "equipoise and above." Copyright © 2017 Elsevier Inc. All rights reserved.

Fetal Liver Bisphenol A Concentrations and Biotransformation Gene Expression Reveal Variable Exposure and Altered Capacity for Metabolism in Humans

PubMed Central

Nahar, Muna S.; Liao, Chunyang; Kannan, Kurunthachalam; Dolinoy, Dana C.

2013-01-01

Widespread exposure to the endocrine active compound, bisphenol A (BPA), is well documented in humans. A growing body of literature suggests adverse health outcomes associated with varying ranges of exposure to BPA. In the current study, we measured the internal dose of free BPA and conjugated BPA and evaluated gene expression of bio-transformation enzymes specific for BPA metabolism in 50 first- and second-trimester human fetal liver samples. Both free BPA and conjugated BPA concentrations varied widely, with free BPA exhibiting three times higher concentrations than conjugated BPA concentrations. As compared to gender-matched adult liver controls, UDP-glucuronyltransferase, sulfotransferase, and steroid sulfatase genes exhibited reduced expression whereas β-glucuronidase mRNA expression remained unchanged in the fetal tissues. This study provides evidence that there is considerable exposure to BPA during human pregnancy and that the capacity for BPA metabolism is altered in the human fetal liver. PMID:23208979

Quantitative assessment of human and pet exposure to Salmonella associated with dry pet foods.

PubMed

Lambertini, Elisabetta; Buchanan, Robert L; Narrod, Clare; Ford, Randall M; Baker, Robert C; Pradhan, Abani K

2016-01-04

Recent Salmonella outbreaks associated with dry pet foods and treats highlight the importance of these foods as previously overlooked exposure vehicles for both pets and humans. In the last decade efforts have been made to raise the safety of this class of products, for instance by upgrading production equipment, cleaning protocols, and finished product testing. However, no comprehensive or quantitative risk profile is available for pet foods, thus limiting the ability to establish safety standards and assess the effectiveness of current and proposed Salmonella control measures. This study sought to develop an ingredients-to-consumer quantitative microbial exposure assessment model to: 1) estimate pet and human exposure to Salmonella via dry pet food, and 2) assess the impact of industry and household-level mitigation strategies on exposure. Data on prevalence and concentration of Salmonella in pet food ingredients, production process parameters, bacterial ecology, and contact transfer in the household were obtained through literature review, industry data, and targeted research. A probabilistic Monte Carlo modeling framework was developed to simulate the production process and basic household exposure routes. Under the range of assumptions adopted in this model, human exposure due to handling pet food is null to minimal if contamination occurs exclusively before extrusion. Exposure increases considerably if recontamination occurs post-extrusion during coating with fat, although mean ingested doses remain modest even at high fat contamination levels, due to the low percent of fat in the finished product. Exposure is highly variable, with the distribution of doses ingested by adult pet owners spanning 3Log CFU per exposure event. Child exposure due to ingestion of 1g of pet food leads to significantly higher doses than adult doses associated with handling the food. Recontamination after extrusion and coating, e.g., via dust or equipment surfaces, may also lead to exposure due to the absence of pathogen reduction steps after extrusion or at consumer households. Exposure is potentially highest when Salmonella is transferred to human food that is left at growth-promoting conditions. This model can be applied to evaluate the impact of alternative Salmonella control measures during production, risk communication to consumers, and regulatory standards. Copyright © 2015 Elsevier B.V. All rights reserved.

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

Free radical release and HSP70 expression in two human immune-relevant cell lines after exposure to 1800 MHz radiofrequency radiation.

PubMed

Lantow, M; Schuderer, J; Hartwig, C; Simkó, M

2006-01-01

The goal of this study was to investigate whether radiofrequency (RF) electromagnetic-field (EMF) exposure at 1800 MHz causes production of free radicals and/or expression of heat-shock proteins (HSP70) in human immune-relevant cell systems. Human Mono Mac 6 and K562 cells were used to examine free radical release after exposure to incubator control, sham, RF EMFs, PMA, LPS, heat (40 degrees C) or co-exposure conditions. Several signals were used: continuous-wave, several typical modulations of the Global System for Mobile Communications (GSM): GSM-non DTX (speaking only), GSM-DTX (hearing only), GSM-Talk (34% speaking and 66% hearing) at specific absorption rates (SARs) of 0.5, 1.0, 1.5 and 2.0 W/kg. Heat and PMA treatment induced a significant increase in superoxide radical anions and in ROS production in the Mono Mac 6 cells when compared to sham and/or incubator conditions. No significant differences in free radical production were detected after RF EMF exposure or in the respective controls, and no additional effects on superoxide radical anion production were detected after co-exposure to RF EMFs+PMA or RF EMFs+LPS. The GSM-DTX signal at 2 W/kg produced a significant difference in free radical production when the data were compared to sham because of the decreasing sham value. This difference disappeared when data were compared to the incubator controls. To determine the involvement of heat-shock proteins as a possible inhibitor of free radical production, we investigated the HSP70 expression level after different RF EMF exposures; no significant effects were detected.

Baseline repeated measures from controlled human exposure studies: associations between ambient air pollution exposure and the systemic inflammatory biomarkers IL-6 and fibrinogen.

PubMed

Thompson, Aaron M S; Zanobetti, Antonella; Silverman, Frances; Schwartz, Joel; Coull, Brent; Urch, Bruce; Speck, Mary; Brook, Jeffrey R; Manno, Michael; Gold, Diane R

2010-01-01

Systemic inflammation may be one of the mechanisms mediating the association between ambient air pollution and cardiovascular morbidity and mortality. Interleukin-6 (IL-6) and fibrinogen are biomarkers of systemic inflammation that are independent risk factors for cardio-vascular disease. We investigated the association between ambient air pollution and systemic inflammation using baseline measurements of IL-6 and fibrinogen from controlled human exposure studies. In this retrospective analysis we used repeated-measures data in 45 nonsmoking subjects. Hourly and daily moving averages were calculated for ozone, nitrogen dioxide, sulfur dioxide, and particulate matter

Potential human health effects of acid rain: report of a workshop

PubMed Central

Goyer, Robert A.; Bachmann, John; Clarkson, Thomas W.; Ferris, Benjamin G.; Graham, Judith; Mushak, Paul; Perl, Daniel P.; Rall, David P.; Schlesinger, Richard; Sharpe, William; Wood, John M.

1985-01-01

This report summarizes the potential impact of the acid precipitation phenomenon on human health. There are two major components to this phenomenon: the predepositional phase, during which there is direct human exposure to acidic substances from ambient air, and the post-depositional phase, in which the deposition of acid materials on water and soil results in the mobilization, transport, and even chemical transformation of toxic metals. Acidification increases bioconversion of mercury to methylmercury, which accumulates in fish, increasing the risk to toxicity in people who eat fish. Increase in water and soil content of lead and cadmium increases human exposure to these metals which become additive to other sources presently under regulatory control. The potential adverse health effects of increased human exposure to aluminum is not known at the present time. PMID:3896772

Maternal occupational cadmium exposure and nonsyndromic orofacial clefts.

PubMed

Suhl, Jonathan; Romitti, Paul A; Cao, Yanyan; Rocheleau, Carissa M; Burns, Trudy L; Conway, Kristin; Rajaraman, Preetha; Agopian, A J; Stewart, Patricia

2018-04-17

Cigarette smoking is a well-studied risk factor for orofacial clefts (OFCs). Little is known about which constituents in cigarette smoke contribute to this teratogenicity in humans. One constituent, cadmium, has been associated with OFCs in animal studies; in humans, the role of maternal cadmium exposure on OFCs, independent of cigarette smoke, is unclear. In particular, the relation between maternal occupational cadmium exposure and OFCs is largely unexplored. Using data from a large, population-based case-control study, we compared expert rater assessed maternal occupational cadmium exposure from self-reported occupational histories during the period 1 month before through 3 months after conception between OFC cases (n = 1,185) and unaffected controls (n = 2,832). Multivariable logistic regression analyses were used to estimate adjusted odds ratios (aORs) and 95% confidence intervals for any (yes/no) and cumulative (no, low, high exposure) occupational cadmium exposures and all OFCs, cleft lip ± cleft palate (CL/P) and cleft palate (CP). Overall, 45 mothers (cases = 13, controls = 32) were rated as having occupational cadmium exposure. Comparing all OFCs to controls, we observed inverse, nonsignificant aORs for any or low exposure, and positive, nonsignificant aORs for high exposure. Where data were available, aORs for CL/P and CP tended to parallel those for all OFCs. To our knowledge, this is the first study to specifically examine maternal occupational cadmium exposure and OFCs, using expert rater exposure assessment. The small numbers of exposed mothers observed, however, led to imprecise estimates. Continued research using more detailed occupational exposure assessment and increased sample sizes is recommended. © 2018 Wiley Periodicals, Inc.

Cost Description and Comparative Cost Efficiency of Post-Exposure Prophylaxis and Canine Mass Vaccination against Rabies in N'Djamena, Chad.

PubMed

Mindekem, Rolande; Lechenne, Monique Sarah; Naissengar, Kemdongarti Service; Oussiguéré, Assandi; Kebkiba, Bidjeh; Moto, Daugla Doumagoum; Alfaroukh, Idriss Oumar; Ouedraogo, Laurent Tinoanga; Salifou, Sahidou; Zinsstag, Jakob

2017-01-01

Rabies claims approximately 59,000 human lives annually and is a potential risk to 3.3 billion people in over 100 countries worldwide. Despite being fatal in almost 100% of cases, human rabies can be prevented by vaccinating dogs, the most common vector, and the timely administration of post-exposure prophylaxis (PEP) to exposed victims. For the control and prevention of human rabies in N'Djamena, the capital city of Chad, a free mass vaccination campaign for dogs was organized in 2012 and 2013. The campaigns were monitored by parallel studies on the incidence of canine rabies based on diagnostic testing of suspect animals and the incidence of human bite exposure recorded at selected health facilities. Based on the cost description of the campaign and the need for PEP registered in health centers, three cost scenarios were compared: cumulative cost-efficiency of (1) PEP alone, (2) dog mass vaccination and PEP, (3) dog mass vaccination, PEP, and maximal communication between human health and veterinary workers (One Health communication). Assuming ideal One Health communication, the cumulative prospective cost of dog vaccination and PEP break even with the cumulative prospective cost of PEP alone in the 10th year from the start of the calculation (2012). The cost efficiency expressed in cost per human exposure averted is much higher with canine vaccination and One Health communication than with PEP alone. As shown in other studies, our cost-effectiveness analysis highlights that canine vaccination is financially the best option for animal rabies control and rabies prevention in humans. This study also provides evidence of the beneficial effect of One Health communication. Only with close communication between the human and animal health sectors will the decrease in animal rabies incidence be translated into a decline for PEP. An efficiently applied One Health concept would largely reduce the cost of PEP in resource poor countries and should be implemented for zoonosis control in general.

Cost Description and Comparative Cost Efficiency of Post-Exposure Prophylaxis and Canine Mass Vaccination against Rabies in N’Djamena, Chad

PubMed Central

Mindekem, Rolande; Lechenne, Monique Sarah; Naissengar, Kemdongarti Service; Oussiguéré, Assandi; Kebkiba, Bidjeh; Moto, Daugla Doumagoum; Alfaroukh, Idriss Oumar; Ouedraogo, Laurent Tinoanga; Salifou, Sahidou; Zinsstag, Jakob

2017-01-01

Rabies claims approximately 59,000 human lives annually and is a potential risk to 3.3 billion people in over 100 countries worldwide. Despite being fatal in almost 100% of cases, human rabies can be prevented by vaccinating dogs, the most common vector, and the timely administration of post-exposure prophylaxis (PEP) to exposed victims. For the control and prevention of human rabies in N’Djamena, the capital city of Chad, a free mass vaccination campaign for dogs was organized in 2012 and 2013. The campaigns were monitored by parallel studies on the incidence of canine rabies based on diagnostic testing of suspect animals and the incidence of human bite exposure recorded at selected health facilities. Based on the cost description of the campaign and the need for PEP registered in health centers, three cost scenarios were compared: cumulative cost-efficiency of (1) PEP alone, (2) dog mass vaccination and PEP, (3) dog mass vaccination, PEP, and maximal communication between human health and veterinary workers (One Health communication). Assuming ideal One Health communication, the cumulative prospective cost of dog vaccination and PEP break even with the cumulative prospective cost of PEP alone in the 10th year from the start of the calculation (2012). The cost efficiency expressed in cost per human exposure averted is much higher with canine vaccination and One Health communication than with PEP alone. As shown in other studies, our cost-effectiveness analysis highlights that canine vaccination is financially the best option for animal rabies control and rabies prevention in humans. This study also provides evidence of the beneficial effect of One Health communication. Only with close communication between the human and animal health sectors will the decrease in animal rabies incidence be translated into a decline for PEP. An efficiently applied One Health concept would largely reduce the cost of PEP in resource poor countries and should be implemented for zoonosis control in general. PMID:28421186

Integrated Science Assessment (ISA) for Sulfur Oxides – Health Criteria (Final)

EPA Science Inventory

The SOx ISA reviews information on atmospheric science, exposure, dosimetry, mode of action, and health effects related to sulfur oxides and sulfur dioxide (SO2), including evidence from controlled human exposure, epidemiologic, and toxicological studies.

Food safety concerns regarding paratuberculosis.

PubMed

Collins, Michael T

2011-11-01

Both ante mortem and post mortem contamination of foods of animal origin commonly occurs. Food manufacturing practices fail to reliably kill Mycobacterium avium subsp. paratuberculosis (MAP) due to its innate resistance to heat and other physical factors. While medical science does not agree on the human health consequences of MAP exposure, this potentially zoonotic pathogen is found in a significant proportion of people with a disease bearing marked similarity to Johne’s disease (ie, Crohn’s disease). Control of MAP infections in farm animals to mitigate the risk of human exposure is one additional reason for on-farm measures to control Johne’s disease.

Organochlorine pesticides in tree bark and human hair in Yunnan Province, China: Concentrations, distributions and exposure pathway.

PubMed

Yuan, Haodong; Jin, Jun; Bai, Yao; Li, Qiuxu; Wang, Ying; Wang, Qinghua

2017-02-15

The concentrations and distributions of organochlorine pesticides (OCPs) in West China were investigated and internal and external exposure of humans to OCPs were assessed by analyzing samples of human hair and tree bark collected in Kaiyuan, in Yunnan Province, China. Dichlorodiphenyltrichloroethane and its metabolites (collectively called DDTs), hexachlorocyclohexanes (HCHs), and hexachlorobenzene (HCB) were the dominant OCPs in the human hair and tree bark samples. The mean total DDT, total HCH, and HCB concentrations in the tree bark samples were 298pg/g dry weight (dw), 100pg/g dw, and 183pg/g dw, respectively, and the mean total DDT, total HCH, and HCB concentrations in the hair samples were 2850pg/g dw, 348pg/g dw, and 1026pg/g dw, respectively. The results indicated that relatively new DDT and lindane inputs have occurred in the study area. DDT and lindane may have been released in products that are used locally. The HCB in the environment in the study area is mainly supplied by long-range atmospheric transport. External exposure was found to be the main factor controlling the p,p'-DDT, γ-HCH, and HCB concentrations in human hair, whereas p,p'-DDE and β-HCH were found to be mainly controlled by internal exposure. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of brief exposure to mitomycin C on cultured human nasal mucosa fibroblasts.

PubMed

Hu, D; Sires, B S; Tong, D C; Royack, G A; Oda, D

2000-03-01

To observe the effect of mitomycin C (MMC) on cultured human nasal mucosa fibroblasts. Cultured human nasal mucosa fibroblasts were exposed to MMC (0.1-0.4 mg/ml) for 1 to 5 minutes. The viability of the fibroblasts was determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay; DNA fragmentation (apoptosis) by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL); apoptotic percentage by flow cytometry; and morphology by light microscopy. A portion of the fibroblasts survived the mitomycin treatment and showed evidence of regrowth within 2 to 3 days. These cells reached confluence in 5 to 7 days. The inhibition rates by MTT assay of 0.4 mg/ml MMC for 5-minute exposures was 31.3%. Dose-response effect was noted with the lower concentrations and shorter exposure times where the inhibition rates were lower (but not significantly so). DNA fragmentation was observed in fibroblasts 24 hours after MMC exposure (0.4 mg/ml) for 5 minutes compared with normal control. The apoptotic rate of fibroblasts treated by 0.4 mg/ml MMC was significantly higher than the control (p < 0.05). Short MMC exposure times have a variable cytotoxic effect and inhibit proliferation of cultured nasal mucosa fibroblasts. MMC also can induce apoptosis with a 5-minute exposure time. Therefore, it is possible that MMC has a complex effect in dacryocystorhinostomy.

In vitro patterning of pluripotent stem cell-derived intestine recapitulates in vivo human development.

PubMed

Tsai, Yu-Hwai; Nattiv, Roy; Dedhia, Priya H; Nagy, Melinda S; Chin, Alana M; Thomson, Matthew; Klein, Ophir D; Spence, Jason R

2017-03-15

The intestine plays a central role in digestion, nutrient absorption and metabolism, with individual regions of the intestine having distinct functional roles. Many examples of region-specific gene expression in the adult intestine are known, but how intestinal regional identity is established during development is a largely unresolved issue. Here, we have identified several genes that are expressed in a region-specific manner in the developing human intestine. Using human embryonic stem cell-derived intestinal organoids, we demonstrate that the duration of exposure to active FGF and WNT signaling controls regional identity. Short-term exposure to FGF4 and CHIR99021 (a GSK3β inhibitor that stabilizes β-catenin) resulted in organoids with gene expression patterns similar to developing human duodenum, whereas longer exposure resulted in organoids similar to ileum. When region-specific organoids were transplanted into immunocompromised mice, duodenum-like organoids and ileum-like organoids retained their regional identity, demonstrating that regional identity of organoids is stable after initial patterning occurs. This work provides insights into the mechanisms that control regional specification of the developing human intestine and provides new tools for basic and translational research. © 2017. Published by The Company of Biologists Ltd.

Fine Ambient Particulate and Ozone Co-Exposures in Durham, North Carolina: Influence of Season on Particle Chemistry and Cardiovascular Responses in Rats

EPA Science Inventory

Epidemiological studies have shown that the presence of one air pollutant modifies the cardiovascular health effects of another while controlled exposure studies in humans have documented synergistic effects of co-exposure to ambient particulate matter (PM) and ozone (O3) on bloo...

Exposure of healthy subjects with emissions from a gas metal arc welding process: part 1--exposure technique and external exposure.

PubMed

Brand, P; Havlicek, P; Steiners, M; Holzinger, K; Reisgen, U; Kraus, T; Gube, M

2013-01-01

Studies concerning welding fume-related adverse health effects in welders are hampered by the heterogeneity of workplace situations, resulting in complex and non-standardized exposure conditions. In order to carry out welding fume exposure studies under controlled and standardized conditions, the Aachen Workplace Simulation Laboratory was developed. This laboratory consists of an emission room, in which welding fume is produced, and an exposure room in which human subjects are exposed to these fumes. Both rooms are connected by a ventilation system which allows the welding fume concentration to be regulated. Particle mass concentration was measured with a TEOM microbalance and the particle number-size distribution using a Grimm SMPS device. In a study, which is the subject of this paper, it has been shown that welding fume concentration can easily be regulated between 1 and about 3 mg m(-3). The chosen concentration can be kept constant for more than 8 h. However, transport of the particles from the emission room into the exposure room leads to a change in particle size distribution, which is probably due to coagulation of the fraction of smallest particles. The Aachen Workplace Simulation Laboratory is suitable for controlled exposure studies with human subjects.

Effects of A 60 Hz Magnetic Field of Up to 50 milliTesla on Human Tremor and EEG: A Pilot Study.

PubMed

Davarpanah Jazi, Shirin; Modolo, Julien; Baker, Cadence; Villard, Sebastien; Legros, Alexandre

2017-11-24

Humans are surrounded by sources of daily exposure to power-frequency (60 Hz in North America) magnetic fields (MFs). Such time-varying MFs induce electric fields and currents in living structures which possibly lead to biological effects. The present pilot study examined possible extremely low frequency (ELF) MF effects on human neuromotor control in general, and physiological postural tremor and electroencephalography (EEG) in particular. Since the EEG cortical mu-rhythm (8-12 Hz) from the primary motor cortex and physiological tremor are related, it was hypothesized that a 60 Hz MF exposure focused on this cortical region could acutely modulate human physiological tremor. Ten healthy volunteers (age: 23.8 ± 4 SD) were fitted with a MRI-compatible EEG cap while exposed to 11 MF conditions (60 Hz, 0 to 50 mT rms , 5 mT rms increments). Simultaneously, physiological tremor (recorded from the contralateral index finger) and EEG (from associated motor and somatosensory brain regions) were measured. Results showed no significant main effect of MF exposure conditions on any of the analyzed physiological tremor characteristics. In terms of EEG, no significant effects of the MF were observed for C1, C3, C5 and CP1 electrodes. However, a significant main effect was found for CP3 and CP5 electrodes, both suggesting a decreased mu-rhythm spectral power with increasing MF flux density. This is however not confirmed by Bonferroni corrected pairwise comparisons. Considering both EEG and tremor findings, no effect of the MF exposure on human motor control was observed. However, MF exposure had a subtle effect on the mu-rhythm amplitude in the brain region involved in tactile perception. Current findings are to be considered with caution due to the small size of this pilot work, but they provide preliminary insights to international agencies establishing guidelines regarding electromagnetic field exposure with new experimental data acquired in humans exposed to high mT-range MFs.

Thermoelectric technique to precisely control hyperthermic exposures of human whole blood.

PubMed

DuBose, D A; Langevin, R C; Morehouse, D H

1996-12-01

The need in military research to avoid exposing humans to harsh environments and reduce animal use requires the development of in vitro models for the study of hyperthermic injury. A thermoelectric module (TEM) system was employed to heat human whole blood (HWB) in a manner similar to that experienced by heat-stroked rats. This system precisely and accurately replicated mild, moderate, and extreme heat-stress exposures. Temperature changes could be monitored without the introduction of a test sample thermistor, which reduced contamination problems. HWB with hematocrits of 45 or 50% had similar heating curves, indicating that the system compensated for differences in sample character. The unit's size permitted its containment within a standard carbon dioxide incubator to further control sample environment. These results indicate that the TEM system can precisely control temperature change in this heat stress in vitro model employing HWB. Information obtained from such a model could contribute to military preparedness.

Directed Differentiation of Human Embryonic Stem Cells into Prostate Organoids In Vitro and its Perturbation by Low-Dose Bisphenol A Exposure.

PubMed

Calderon-Gierszal, Esther L; Prins, Gail S

2015-01-01

Studies using rodent and adult human prostate stem-progenitor cell models suggest that developmental exposure to the endocrine disruptor Bisphenol-A (BPA) can predispose to prostate carcinogenesis with aging. Unknown at present is whether the embryonic human prostate is equally susceptible to BPA during its natural developmental window. To address this unmet need, we herein report the construction of a pioneer in vitro human prostate developmental model to study the effects of BPA. The directed differentiation of human embryonic stem cells (hESC) into prostatic organoids in a spatial system was accomplished with precise temporal control of growth factors and steroids. Activin-induced definitive endoderm was driven to prostate specification by combined exposure to WNT10B and FGF10. Matrigel culture for 20-30 days in medium containing R-Spondin-1, Noggin, EGF, retinoic acid and testosterone was sufficient for mature prostate organoid development. Immunofluorescence and gene expression analysis confirmed that organoids exhibited cytodifferentiation and functional properties of the human prostate. Exposure to 1 nM or 10 nM BPA throughout differentiation culture disturbed early morphogenesis in a dose-dependent manner with 1 nM BPA increasing and 10 nM BPA reducing the number of branched structures formed. While differentiation of branched structures to mature organoids seemed largely unaffected by BPA exposure, the stem-like cell population increased, appearing as focal stem cell nests that have not properly entered lineage commitment rather than the rare isolated stem cells found in normally differentiated structures. These findings provide the first direct evidence that low-dose BPA exposure targets hESC and perturbs morphogenesis as the embryonic cells differentiate towards human prostate organoids, suggesting that the developing human prostate may be susceptible to disruption by in utero BPA exposures.

Naphthalene and Naphthoquinone: Distributions and Human Exposure in the Los Angeles Basin

NASA Astrophysics Data System (ADS)

Lu, R.; Wu, J.; Turco, R.; Winer, A. M.; Atkinson, R.; Paulson, S.; Arey, J.; Lurmann, F.

2003-12-01

Naphthalene is the simplest and most abundant of the polycyclic aromatic hydrocarbons (PAHs). Naphthalene is found primarily in the gas-phase and has been detected in both outdoor and indoor samples. Evaporation from naphthalene-containing products (including gasoline), and during refining operations, are important sources of naphthalene in air. Naphthalene is also emitted during the combustion of fossil fuels and wood, and is a component of vehicle exhaust. Exposure to high concentrations of naphthalene can damage or destroy red blood cells, causing hemolytic anemia. If inhaled over a long period of time, naphthalene may cause kidney and liver damage, skin allergy and dermatitis, cataracts and retinal damage, as well as attack the central nervous system. Naphthalene has been found to cause cancer as a result of inhalation in animal tests. Naphthoquinones are photooxidation products of naphthalene and the potential health effects of exposure to these quinones are a current focus of research. We are developing and applying models that can be used to assess human exposure to naphthalene and its photooxidation products in major air basins such as California South Coast Air Basin (SoCAB). The work utilizes the Surface Meteorology and Ozone Generation (SMOG) airshed model, and the REgional Human EXposure (REHEX) model, including an analysis of individual exposure. We will present and discuss simulations of basin-wide distributions of, and human exposures to, naphthalene and naphthoquinone, with emphasis on the uncertainties in these estimates of atmospheric concentrations and human exposure. Regional modeling of pollutant sources and exposures can lead to cost-effective and optimally health-protective emission control strategies.

Where to start with pest control

Science.gov Websites

; Environment Human Health Animal Health Safe Use Practices Food Safety Environment Air Water Soil Wildlife Ingredients Low-Risk Pesticides Organic Pesticide Ingredients Pesticide Incidents Human Exposure Pet Exposure :00PM Pacific Time, Mon-Fri A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A-Z Index Health &

The Air Pollution Exposure Laboratory (APEL) for controlled human exposure to diesel exhaust and other inhalants: characterization and comparison to existing facilities.

PubMed

Birger, Nicholas; Gould, Timothy; Stewart, James; Miller, Mark R; Larson, Timothy; Carlsten, Chris

2011-03-01

The Air Pollution Exposure Laboratory (APEL) was designed for the controlled inhalation of human subjects to aged and diluted diesel exhaust (DE) to mimic "real-world" occupational and environmental conditions. An EPA Tier 3-compliant, 6.0 kW diesel generator is operated under discrete cyclic loads to simulate diesel on-road emissions. The engine accepts standard ultra-low sulfur diesel or a variety of alternative fuels (such as biodiesel) via a partitioned tank. A portion of raw exhaust is drawn into the primary dilution system and is diluted 9:1 with compressed air at standard temperature (20°C) and humidity (40%) levels. The exhaust is further diluted approximately 25:1 by high efficiency particulate air (HEPA)-filtered air (FA) and then aged for 4 min before entering the 4 × 6 × 7-foot exposure booth. An optional HEPA filter path immediately proximal to the booth can generate a particle-reduced (gas-enriched) exposure. In-booth particulate is read by a nephelometer to provide an instantaneous light scattering coefficient for closed-loop system control. A Scanning Mobility Particle Sizer and multi-stage impactor measures particle size distribution. Filter sampling allows determination of sessional average concentrations of size-fractionated and unfractionated particulate oxidative potential, elemental carbon, organic carbon and trace elements. Approximately 300 μg/m(3) PM(2.5) is routinely achievable at APEL and is well characterized in terms of oxidative potential and elemental components. APEL efficiently creates fresh DE, appropriately aged and diluted for human experimentation at safe yet realistic concentrations. Description of exposure characteristics allows comparison to other international efforts to deepen the current evidence base regarding the health effects of DE.

Lactate and pH evaluation in exhausted humans with prolonged TASER X26 exposure or continued exertion.

PubMed

Ho, Jeffrey D; Dawes, Donald M; Cole, Jon B; Hottinger, Julie C; Overton, Kenneth G; Miner, James R

2009-09-10

Safety concerns about TASER Conducted Electrical Weapon (CEW) use and media reports of deaths after exposure have been expressed. CEWs are sometimes used on exhausted subjects to end resistance. The alternative is often a continued struggle. It is unclear if CEW use is metabolically different than allowing a continued struggle. We sought to determine if CEW exposure on exhausted humans caused worsening acidosis when compared with continued exertion. This was a prospective study of human volunteers recruited during a CEW training course. Volunteers were from several different occupations and represented a wide range of ages and body mass index characteristics. Medical histories, baseline pH and lactate values were obtained. Patients were assigned to one of four groups: 2 control groups consisting of Exertion only and CEW Exposure only, and the 2 experimental groups that were Exertion plus CEW Exposure and Exertion plus additional Exertion. Blood sampling occurred after Exertion and after any CEW exposure. This was repeated every 2-min until 20 min after protocol completion. Descriptive statistics were used to compare the four groups. The experimental groups and the control groups were compared individually at each time point using Wilcoxon rank sum tests. Lactate and pH association was assessed using multiple linear regression. Forty subjects were enrolled. There were no median pH or lactate differences between CEW Exposure groups at baseline, or between Exertion protocol groups immediately after completion. The CEW Exposure only group had higher pH and lower lactate values at all time points after exposure than the Exertion only group. After completing the Exertion protocol, there was no difference in the pH or lactate values between the continued Exertion group and the CEW Exposure group at any time points. Subjects who had CEW Exposure only had higher pH and lower lactate values than subjects who completed the Exertion protocol only. CEW exposure does not appear to worsen acidosis in exhausted subjects any differently than briefly continued exertion.

ACUTE CHANGES IN SPUTUM COLLECTED FROM EXPOSED HUMAN SUBJECTS IN MINING CONDITIONS

PubMed Central

Wong, Simon S.; Sun, Nina N.; Miller, Hugh B.; Witten, Mark L.; Burgess, Jefferey L.

2015-01-01

Neprilysin (NEP) is a key cell surface peptidase in the maintenance of airway homeostasis and the development of pulmonary disorders. However, little information is available about the effect of particulate matter (PM) on airway NEP. In this controlled human exposure study, changes in induced sputum were measured in eleven subjects at baseline, overshot (OS) mucking, and diesel exhaust (DE) exposure days. Neither OS condition nor DE exposure was found to induce significant changes in total protein, but DE induced significant increases in cell numbers of macrophages and epithelium. Moreover, significant increases in soluble NEP were observed following OS mining dust particulates (0.43 ± 0.06, p = 0.023) and DE exposure (0.30 ± 0.04, p = 0.035) when compared with the baseline control (0.40 ± 0.03), with 42% and 31% average net increase, respectively. Pearson’s correlation analyses indicated that sputum NEP activity were significantly associated with personal exposure product [Elemental carbon concentration, mg/m3 X time, min. (C X T)]. Data suggest that the changes in NEP activity may be an early, accurate endpoint for airway epithelial injury and provided a new insight into the mechanism of the airway effects in these exposure conditions. PMID:20384431

Nitrogen Dioxide Exposure and Airway Responsiveness in Individuals with Asthma

EPA Science Inventory

Controlled human exposure studies evaluating the effect of inhaled NO2 on the inherent responsiveness of the airways to challenge by bronchoconstricting agents have had mixed results. In general, existing meta-analyses show statistically significant effects of NO2 on the airway r...

Rapid microRNA changes in airways of human volunteers after controlled exposure to air pollutants

EPA Science Inventory

Introduction/Rationale: Exposure to air pollutants, including ozone and diesel exhaust (DE) are known to cause acute cardiopulmonary dysfunction; however, the molecular mechanisms underlying these changes remain elusive. One mechanism for rapid regulation of multiple genes is a...

Tumor-based case-control studies of infection and cancer: muddling the when and where of molecular epidemiology.

PubMed

Engels, Eric A; Wacholder, Sholom; Katki, Hormuzd A; Chaturvedi, Anil K

2014-10-01

We describe the "tumor-based case-control" study as a type of epidemiologic study used to evaluate associations between infectious agents and cancer. These studies assess exposure using diseased tissues from affected individuals (i.e., evaluating tumor tissue for cancer cases), but they must utilize nondiseased tissues to assess control subjects, who do not have the disease of interest. This approach can lead to exposure misclassification in two ways. First, concerning the "when" of exposure assessment, retrospective assessment of tissues may not accurately measure exposure at the key earlier time point (i.e., during the etiologic window). Second, concerning the "where" of exposure assessment, use of different tissues in cases and controls can have different accuracy for detecting the exposure (i.e., differential exposure misclassification). We present an example concerning the association of human papillomavirus with various cancers, where tumor-based case-control studies likely overestimate risk associated with infection. In another example, we illustrate how tumor-based case-control studies of Helicobacter pylori and gastric cancer underestimate risk. Tumor-based case-control studies can demonstrate infection within tumor cells, providing qualitative information about disease etiology. However, measures of association calculated in tumor-based case-control studies are prone to over- or underestimating the relationship between infections and subsequent cancer risk. ©2014 American Association for Cancer Research.

2013 Annual Report of the American Association of Poison Control Centers’ National Poison Data System (NPDS): 31st Annual Report

PubMed Central

Mowry, James B.; Spyker, Daniel A.; Cantilena, Louis R.; McMillan, Naya; Ford, Marsha

2014-01-01

ABSTRACT Background: This is the 31st Annual Report of the American Association of Poison Control Centers’ (AAPCC) National Poison Data System (NPDS). As of January 1, 2013, 57 of the nation's poison centers (PCs) uploaded case data automatically to NPDS. The upload interval was 8.08 [7.10, 11.63] (median [25%, 75%]) minutes, creating a near real-time national exposure and information database and surveillance system. Methodology: We analyzed the case data tabulating specific indices from NPDS. The methodology was similar to that of previous years. Where changes were introduced, the differences are identified. Poison center (PC) cases with medical outcomes of death were evaluated by a team of 38 medical and clinical toxicologist reviewers using an ordinal scale of 1–6 to assess the Relative Contribution to Fatality (RCF) of the exposure to the death. Results: In 2013, 3,060,122 closed encounters were logged by NPDS: 2,188,013 human exposures, 59,496 animal exposures, 806,347 information calls, 6,116 human-confirmed nonexposures, and 150 animal-confirmed nonexposures. Total encounters showed a 9.3% decline from 2012, while health care facility human exposure calls were essentially flat, decreasing by 0.1%.All information calls decreased 21.4% and health care facility (HCF) information calls decreased 8.5%, medication identification requests (drug ID) decreased 26.8%, and human exposures reported to US PCs decreased 3.8%. Human exposures with less serious outcomes have decreased 3.7% per year since 2008 while those with more serious outcomes (moderate, major or death) have increased by 4.7% per year since 2000. The top five substance classes most frequently involved in all human exposures were analgesics (11.5%), cosmetics/personal care products (7.7%), household cleaning substances (7.6%), sedatives/hypnotics/antipsychotics (5.9%), and antidepressants (4.2%). Sedative/hypnotics/antipsychotics exposures as a class increased most rapidly (2,559 calls/year) over the last 13 years for cases showing more serious outcomes. The top five most common exposures in children of 5 years or less were cosmetics/personal care products (13.8%), household cleaning substances (10.4%), analgesics (9.8%), foreign bodies/toys/miscellaneous (6.9%), and topical preparations (6.1%). Drug identification requests comprised 50.7% of all information calls. NPDS documented 2,477 human exposures resulting in death with 2,113 human fatalities judged related (RCF of 1, undoubtedly responsible; 2, probably responsible; or 3, contributory). Conclusions: These data support the continued value of PC expertise and need for specialized medical toxicology information to manage the more severe exposures, despite a decrease in calls involving less severe exposures. Unintentional and intentional exposures continue to be a significant cause of morbidity and mortality in the United States. The near real-time, always current status of NPDS represents a national public health resource to collect and monitor US exposure cases and information calls. The continuing mission of NPDS is to provide a nationwide infrastructure for public health surveillance for all types of exposures, public health event identification, resilience response and situational awareness tracking. NPDS is a model system for the nation and global public health. PMID:25559822

Prenatal and postnatal cocaine exposure predict teen cocaine use

PubMed Central

Delaney-Black, Virginia; Chiodo, Lisa M.; Hannigan, John H.; Greenwald, Mark K.; Janisse, James; Patterson, Grace; Huestis, Marilyn A.; Partridge, Robert T.; Ager, Joel; Sokol, Robert J.

2015-01-01

Preclinical studies have identified alterations in cocaine and alcohol self-administration and behavioral responses to pharmacological challenges in adolescent offspring following prenatal exposure. To date, no published human studies have evaluated the relation between prenatal cocaine exposure and postnatal adolescent cocaine use. Human studies of prenatal cocaine-exposed children have also noted an increase in behaviors previously associated with substance use/abuse in teens and young adults, specifically childhood and teen externalizing behaviors, impulsivity, and attention problems. Despite these findings, human research has not addressed prior prenatal exposure as a potential predictor of teen drug use behavior. The purpose of this study was to evaluate the relations between prenatal cocaine exposure and teen cocaine use in a prospective longitudinal cohort (n = 316) that permitted extensive control for child, parent and community risk factors. Logistic regression analyses and Structural Equation Modeling revealed that both prenatal exposure and postnatal parent/caregiver cocaine use were uniquely related to teen use of cocaine at age 14 years. Teen cocaine use was also directly predicted by teen community violence exposure and caregiver negativity, and was indirectly related to teen community drug exposure. These data provide further evidence of the importance of prenatal exposure, family and community factors in the intergenerational transmission of teen/young adult substance abuse/use. PMID:20609384

Prenatal and postnatal cocaine exposure predict teen cocaine use.

PubMed

Delaney-Black, Virginia; Chiodo, Lisa M; Hannigan, John H; Greenwald, Mark K; Janisse, James; Patterson, Grace; Huestis, Marilyn A; Partridge, Robert T; Ager, Joel; Sokol, Robert J

2011-01-01

Preclinical studies have identified alterations in cocaine and alcohol self-administration and behavioral responses to pharmacological challenges in adolescent offspring following prenatal exposure. To date, no published human studies have evaluated the relation between prenatal cocaine exposure and postnatal adolescent cocaine use. Human studies of prenatal cocaine-exposed children have also noted an increase in behaviors previously associated with substance use/abuse in teens and young adults, specifically childhood and teen externalizing behaviors, impulsivity, and attention problems. Despite these findings, human research has not addressed prior prenatal exposure as a potential predictor of teen drug use behavior. The purpose of this study was to evaluate the relations between prenatal cocaine exposure and teen cocaine use in a prospective longitudinal cohort (n=316) that permitted extensive control for child, parent and community risk factors. Logistic regression analyses and Structural Equation Modeling revealed that both prenatal exposure and postnatal parent/caregiver cocaine use were uniquely related to teen use of cocaine at age 14 years. Teen cocaine use was also directly predicted by teen community violence exposure and caregiver negativity, and was indirectly related to teen community drug exposure. These data provide further evidence of the importance of prenatal exposure, family and community factors in the intergenerational transmission of teen/young adult substance abuse/use. Copyright © 2010 Elsevier Inc. All rights reserved.

Human exposures to pesticides in the United States.

PubMed

Langley, Ricky L; Mort, Sandra Amiss

2012-01-01

Pesticides are used in most homes, businesses, and farms to control a variety of pests, including insects, weeds, fungi, rodents, and even microbial organisms. Inappropriate use of pesticides can lead to adverse effects to humans and the environment. This study provides updated information on the magnitude of adverse pesticide exposures in the United States. Data on pesticide exposure were obtained from calls to poison control centers (PCCs) reported by the American Association of Poison Control Centers. Estimates of emergency department visits, hospitalizations, and health care costs were reported by the Agency for Healthcare Research and Quality (AHRQ), and deaths from pesticide poisonings reported by the Centers for Disease Control and Prevention (CDC) WONDER (Wide-ranging Online Data for Epidemiologic Research). An average of 23 deaths occur each year with pesticides as the underlying cause of death, most due to suicidal ingestions. An average of 130,136 calls to poison control centers were reported from 2006 to 2010, with an average of 20,116 cases (17.8%) treated in health care facilities annually. AHQR reported an annual average of 7385 emergency room visits during 2006 to 2008, and 1419 annual hospitalizations during 2005 to 2009. Excluding cost from lost work time, hospital physician fees, and pesticide-induced cancers, the annual national cost associated with pesticide exposures was estimated as nearly $200 million USD based on data from emergency department visits, hospitalizations, and for deaths. Pesticide exposures remain a significant public health issue. Health care providers, cooperative extension agents, and pesticide manufactures can help prevent exposures by increasing education of parents and workers, encourage use of less toxic agents, and encourage the practice of integrated pest management.

Effect of organic carbon on sorption of human adenovirus to soil particles and laboratory containers

EPA Science Inventory

A key factor controlling the relationship between virus release and human exposure is how virus particles interact with soils, sediments and other solid particles in the environment and in engineered treatment systems. Finding no previous investigations of human adenovirus (HAdV)...

Airway and serum adipokines after allergen and diesel exposure in a controlled human crossover study of atopic adults.

PubMed

Kramer, Marabeth M; Hirota, Jeremy A; Sood, Akshay; Teschke, Kay; Carlsten, Christopher

2017-04-01

Adipokines are mediators released from adipose tissue. These proteins are regarded as active elements of systemic and pulmonary inflammation, whose dysregulation can alter an individual's risk of developing allergic lung diseases. Despite this knowledge, adipokine responses to inhaled stimuli are poorly understood. We sought to measure serum and lung adiponectin, leptin, and resistin in an atopic adult study population following exposure to allergen and diesel exhaust (DE). Two types of lung samples including bronchoalveolar lavage (BAL) and bronchial wash (BW), and a time course of serum samples, were collected from the 18 subjects who participated in the randomized, double-blinded controlled human study. The two crossover exposure triads in this study were inhaled DE and filtered air each followed by instilled allergen or saline. Serum and lung adipokine responses to these exposures were quantified using enzyme-linked immunosorbent assay. Allergen significantly increased adiponectin and leptin in BAL, and adiponectin in the BW 48 hours after exposure. Serum leptin and resistin responses were not differentially affected by exposure, but varied over time. Coexposure with DE and allergen revealed significant correlations between the adiponectin/leptin ratio and FEV 1 changes and airway responsiveness measures. Changes in lung and serum adipokines in response to allergen exposure were identified in the context of a controlled exposure study. Coexposure identified a potentially protective role of adiponectin in the lung. This response was not observed in those with baseline airway hyper-responsiveness, or after allergen exposure alone. The clinical relevance of this potentially adaptive adipokine pattern warrants further study. Copyright © 2016 Elsevier Inc. All rights reserved.

Mass spectrometry profiling reveals altered plasma levels of monohydroxy fatty acids and related lipids in healthy humans after controlled exposure to biodiesel exhaust.

PubMed

Gouveia-Figueira, Sandra; Karimpour, Masoumeh; Bosson, Jenny A; Blomberg, Anders; Unosson, Jon; Sehlstedt, Maria; Pourazar, Jamshid; Sandström, Thomas; Behndig, Annelie F; Nording, Malin L

2018-08-14

Experimental human exposure studies are an effective tool to study adverse health effects from acute inhalation of particulate matter and other constituents of air pollution. In this randomized and double-blinded crossover study, we investigated the systemic effect on bioactive lipid metabolite levels after controlled biodiesel exhaust exposure of healthy humans and compared it to filtered air at a separate exposure occasion. Eicosanoids and other oxylipins, as well as endocannabinoids and related lipids, were quantified in plasma from 14 healthy volunteers at baseline and at three subsequent time points (2, 6, and 24 h) after 1 h exposure sessions. Protocols based on liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS) methods were developed to detect temporal changes in circulating levels after biodiesel exhaust exposure. The exhaust was generated by a diesel engine fed with an undiluted rapeseed methyl ester fuel. Among the 51 analyzed lipid metabolites, PGF 2α , 9,10-DiHOME, 9-HODE, 5-HETE, 11-HETE, 12-HETE, and DEA displayed significant responsiveness to the biodiesel exhaust exposure as opposed to filtered air. Of these, 9-HODE and 5-HETE at 24 h survived the 10% false discovery rate cutoff (p < 0.003). Hence, the majority of the responsive lipid metabolites were monohydroxy fatty acids. We conclude that it is possible to detect alterations in circulating bioactive lipid metabolites in response to biodiesel exhaust exposure using LC-MS/MS, with emphasis on metabolites with inflammation related properties and implications on cardiovascular health and disease. These observations aid future investigations on air pollution effects, especially with regard to cardiovascular outcomes. Copyright © 2018 Elsevier B.V. All rights reserved.

Short-Term Exposure to Trifluralin in the In Vivo Rat Model

EPA Science Inventory

Trifluralin is a selective, preemergence 2,6-dinitroaniline herbicide used to control many annual grasses and broadleaf weeds. Human exposure is likely to occur via consumption of vegetables and fruit and possibly fish from trifluralin run off in water. It has previously been r...

DNA Damage among Wood Workers Assessed with the Comet Assay

PubMed Central

Bruschweiler, Evin Danisman; Wild, Pascal; Huynh, Cong Khanh; Savova-Bianchi, Dessislava; Danuser, Brigitta; Hopf, Nancy B.

2016-01-01

Exposure to wood dust, a human carcinogen, is common in wood-related industries, and millions of workers are occupationally exposed to wood dust worldwide. The comet assay is a rapid, simple, and sensitive method for determining DNA damage. The objective of this study was to investigate the DNA damage associated with occupational exposure to wood dust using the comet assay (peripheral blood samples) among nonsmoking wood workers (n = 31, furniture and construction workers) and controls (n = 19). DNA damage was greater in the group exposed to composite wood products compared to the group exposed to natural woods and controls (P < 0.001). No difference in DNA damage was observed between workers exposed to natural woods and controls (P = 0.13). Duration of exposure and current dust concentrations had no effect on DNA damage. In future studies, workers’ exposures should include cumulative dust concentrations and exposures originating from the binders used in composite wood products. PMID:27398027

Exposure Is Not Enough: Suppressing Stimuli from Awareness Can Abolish the Mere Exposure Effect

PubMed Central

Newell, Ben R.; Pearson, Joel

2013-01-01

Passive exposure to neutral stimuli increases subsequent liking of those stimuli – the mere exposure effect. Because of the broad implications for understanding and controlling human preferences, the role of conscious awareness in mere exposure has received much attention. Previous studies have claimed that the mere exposure effect can occur without conscious awareness of the stimuli. In two experiments, we applied a technique new to the mere exposure literature, called continuous flash suppression, to expose stimuli for a controlled duration with and without awareness. To ensure the reliability of the awareness manipulation, awareness was monitored on a trial-by-trial basis. Our results show that under these conditions the mere exposure effect does not occur without conscious awareness. In contrast, only when participants were aware of the stimuli did exposure increase liking and recognition. Together these data are consistent with the idea that the mere exposure effect requires conscious awareness and has important implications for theories of memory and affect. PMID:24147067

Exposure is not enough: suppressing stimuli from awareness can abolish the mere exposure effect.

PubMed

de Zilva, Daniel; Vu, Luke; Newell, Ben R; Pearson, Joel

2013-01-01

Passive exposure to neutral stimuli increases subsequent liking of those stimuli--the mere exposure effect. Because of the broad implications for understanding and controlling human preferences, the role of conscious awareness in mere exposure has received much attention. Previous studies have claimed that the mere exposure effect can occur without conscious awareness of the stimuli. In two experiments, we applied a technique new to the mere exposure literature, called continuous flash suppression, to expose stimuli for a controlled duration with and without awareness. To ensure the reliability of the awareness manipulation, awareness was monitored on a trial-by-trial basis. Our results show that under these conditions the mere exposure effect does not occur without conscious awareness. In contrast, only when participants were aware of the stimuli did exposure increase liking and recognition. Together these data are consistent with the idea that the mere exposure effect requires conscious awareness and has important implications for theories of memory and affect.

Early exposure to thirdhand cigarette smoke affects body mass and the development of immunity in mice

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

Hang, Bo; Snijders, Antoine M.; Huang, Yurong

Thirdhand smoke (THS) is the fraction of cigarette smoke that persists in indoor environments after smoking. We investigated the effects of neonatal and adult THS exposure on bodyweight and blood cell populations in C57BL/6 J mice. At the end of neonatal exposure, THS-treated male and female mice had significantly lower bodyweight than their respective control mice. However, five weeks after neonatal exposure ended, THS-treated mice weighed the same as controls. In contrast, adult THS exposure did not change bodyweight of mice. On the other hand, both neonatal and adult THS exposure had profound effects on the hematopoietic system. Fourteen weeksmore » after neonatal THS exposure ended, eosinophil number and platelet volume were significantly higher, while hematocrit, mean cell volume, and platelet counts were significantly lower compared to control. Similarly, adult THS exposure also decreased platelet counts and increased neutrophil counts. Moreover, both neonatal and adult THS exposure caused a significant increase in percentage of B-cells and significantly decreased percentage of myeloid cells. Our results demonstrate that neonatal THS exposure decreases bodyweight and that THS exposure induces persistent changes in the hematopoietic system independent of age at exposure. These results also suggest that THS exposure may have adverse effects on human health.« less

Early exposure to thirdhand cigarette smoke affects body mass and the development of immunity in mice

DOE PAGES

Hang, Bo; Snijders, Antoine M.; Huang, Yurong; ...

2017-02-03

Thirdhand smoke (THS) is the fraction of cigarette smoke that persists in indoor environments after smoking. We investigated the effects of neonatal and adult THS exposure on bodyweight and blood cell populations in C57BL/6 J mice. At the end of neonatal exposure, THS-treated male and female mice had significantly lower bodyweight than their respective control mice. However, five weeks after neonatal exposure ended, THS-treated mice weighed the same as controls. In contrast, adult THS exposure did not change bodyweight of mice. On the other hand, both neonatal and adult THS exposure had profound effects on the hematopoietic system. Fourteen weeksmore » after neonatal THS exposure ended, eosinophil number and platelet volume were significantly higher, while hematocrit, mean cell volume, and platelet counts were significantly lower compared to control. Similarly, adult THS exposure also decreased platelet counts and increased neutrophil counts. Moreover, both neonatal and adult THS exposure caused a significant increase in percentage of B-cells and significantly decreased percentage of myeloid cells. Our results demonstrate that neonatal THS exposure decreases bodyweight and that THS exposure induces persistent changes in the hematopoietic system independent of age at exposure. These results also suggest that THS exposure may have adverse effects on human health.« less

Epidemiological characteristics and post-exposure prophylaxis of human rabies in Chongqing, China, 2007-2016.

PubMed

Qi, Li; Su, Kun; Shen, Tao; Tang, Wenge; Xiao, Bangzhong; Long, Jiang; Zhao, Han; Chen, Xi; Xia, Yu; Xiong, Yu; Xiao, Dayong; Feng, Liangui; Li, Qin

2018-01-03

According to the global framework of eliminating human rabies, China is responding to achieve the target of zero human death from dog-mediated rabies by 2030. Chongqing is the largest municipality directly under central government in China. We described the epidemiological characteristics and post-exposure prophylaxis (PEP) of human rabies in this area, in order to provide a reliable epidemiology basis for further control and prevention of human rabies. The most updated epidemiological data for human rabies cases from 2007 to 2016 in Chongqing were collected from the National Disease Reporting Information System. A standardized questionnaire was applied to the human rabies cases or family members of cases as proxy to investigate the PEP situation. A total of 809 fatal human rabies cases were reported in Chongqing from 2007 to 2016. There was a trend of gradual annual decline about number of cases from 2007 to 2013, followed by stable levels until 2016. Rabies was mostly reported in summer and autumn; a majority of cases were noted in farmers (71.8%), especially in males (65.3%). The cases aged 35-74 and 5-14 years old accounted for 83.8% of all the cases. We collected information of 548 human rabies cases' rabies exposure and PEP situation. Of those, 95.8% of human rabies cases were victims of dog bites or scratch, and 53.3% of these dogs were identified as stray dogs. Only 4.0% of the domestic dogs were reported to have been vaccinated previously. After exposure, 87.8% of the 548 human rabies cases did not seek any medical services. Further investigation showed that none of the 548 cases received timely and properly standardized PEP. Human rabies remains a major public health problem in Chongqing, China. Dogs are the main reservoir and source of human rabies infection. Unsuccessful control of canine rabies and inadequate PEP of cases might be the main factors leading to the serious human rabies epidemic in this area. An integrated "One Health" approach should be encouraged and strengthened in this area; with combined effort it would be possible to achieve the elimination of human rabies in the expected date.

Repeated or long-duration TASER electronic control device exposures: acidemia and lack of respiration.

PubMed

Jauchem, James R

2010-03-01

Conducted energy weapons (CEWs), such as TASER devices, may be applied to subjects in repeated or long-duration modes. Such applications may result in more potentially harmful effects (as reflected in blood factor changes) than shorter exposures. In this review, results from a number of studies of repeated and long-duration CEW exposures in an animal model are examined. Additionally, a few limited investigations of shorter CEW applications to human subjects are considered. Specifically, in anesthetized swine, increased blood acidity (acidemia) and lack of effective respiration were found to be common during or immediately after CEW exposure. The acidemia could have been due to both metabolic and respiratory acidosis. A relatively rapid recovery toward baseline pH levels occurred. The lack of effective respiration has not been verified in experiments of CEW applications to human subjects; however, in some incidents of human deaths after CEW exposures subjects have been reported to stop breathing immediately after the exposure. It is not known if all human subjects exposed to CEW applications in the field (often "on drugs" or "in excited delirium") would be able to maintain adequate breathing. Since a limited number of short CEW applications would be less likely to cause adverse effects, however, CEWs can still be a valuable tool for law enforcement activities.

Interim methods for development of inhalation reference concentrations. Draft report

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

Blackburn, K.; Dourson, M.; Erdreich, L.

1990-08-01

An inhalation reference concentration (RfC) is an estimate of continuous inhalation exposure over a human lifetime that is unlikely to pose significant risk of adverse noncancer health effects and serves as a benchmark value for assisting in risk management decisions. Derivation of an RfC involves dose-response assessment of animal data to determine the exposure levels at which no significant increase in the frequency or severity of adverse effects between the exposed population and its appropriate control exists. The assessment requires an interspecies dose extrapolation from a no-observed-adverse-effect level (NOAEL) exposure concentration of an animal to a human equivalent NOAEL (NOAEL(HBC)).more » The RfC is derived from the NOAEL(HBC) by the application of generally order-of-magnitude uncertainty factors. Intermittent exposure scenarios in animals are extrapolated to chronic continuous human exposures. Relationships between external exposures and internal doses depend upon complex simultaneous and consecutive processes of absorption, distribution, metabolism, storage, detoxification, and elimination. To estimate NOAEL(HBC)s when chemical-specific physiologically-based pharmacokinetic models are not available, a dosimetric extrapolation procedure based on anatomical and physiological parameters of the exposed human and animal and the physical parameters of the toxic chemical has been developed which gives equivalent or more conservative exposure concentrations values than those that would be obtained with a PB-PK model.« less

Report: Progress Made, but Improvements Needed at CTS of Asheville Superfund Site in North Carolina to Advance Cleanup Pace and Reduce Potential Exposure

EPA Pesticide Factsheets

Report #16-P-0296, August 31, 2016. EPA Region 4 can accelerate the cleanup and completeness of work, and improve public communications, to better control human exposure to unsafe industrial contamination at the CTS site.

75 FR 80819 - Draft Current Intelligence Bulletin “Occupational Exposure to Carbon Nanotubes and Nanofibers”

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-23

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention [Docket Number NIOSH 161-A] Draft Current Intelligence Bulletin ``Occupational Exposure to Carbon Nanotubes and... carbon nanotubes and to issue its findings on the potential health risks. A draft Current Intelligence...

THE RELATIONSHIP BETWEEN BOTH REAL-TIME AND TIME-INTEGRATED COARSE AND FINE PARTICULATE MATTER AT AN URBAN SITE IN LOS ANGELES

EPA Science Inventory

Population exposure to ambient particulate matter (PM) has received considerable attention due to the association between ambient particulate concentrations and mortality. Current toxicological studies and controlled human and animal exposures suggest that all size fractions of...

Accountability: Evaluating the Impact of Regulatory Policies on Air Quality, Human Health, and the Environment

EPA Science Inventory

This presentation discusses "accountability"; e.g., do emission-control regulations really reduce exposure to pollutants and improve human health? In this presentation, we provide examples of how to examine this and related questions.

Leukemia after exposure to benzene: temporal trends and implications for standards.

PubMed

Finkelstein, M M

2000-07-01

Benzene is a human leukemogen. Risk assessment, and the setting of occupational and environmental standards, has assumed that risk is constant in time after a unit of exposure. Leukemia risk is known to vary with time after exposure to ionizing radiation. A matched case-control study of leukemia risk in relation to the temporal pattern of benzene exposures was performed using data from the National Institute of Occupational Safety and Health. Leukemia risk following exposure to benzene varied with time in a manner similar to that following exposure to ionizing radiation. More recent exposures were more strongly associated with risk than were more distant ones. There was no significant relation between leukemia death and benzene exposures incurred more than 20 years previously. Recent analyses of specific occupational and environmental carcinogens, including benzene and radon, have indicated that cancer risk tends to decline as the time from exposure increases. This suggests that standards for the control of occupational or public risk must be selected to control exposures over a narrower time frame than the usual lifetime one. In the case of benzene, it would appear that risk is attributable primarily to exposures incurred during the previous 10 to 20 years, with exposures in the most recent 10 years being the most potent. To limit risk, exposures must be controlled during that interval. It is important that epidemiologists explore the temporal pattern of risk in their studies to facilitate the risk assessment of other carcinogens. Copyright 2000 Wiley-Liss, Inc.

Improving exposure assessment in environmental epidemiology: Application of spatio-temporal visualization tools

NASA Astrophysics Data System (ADS)

Meliker, Jaymie R.; Slotnick, Melissa J.; Avruskin, Gillian A.; Kaufmann, Andrew; Jacquez, Geoffrey M.; Nriagu, Jerome O.

2005-05-01

A thorough assessment of human exposure to environmental agents should incorporate mobility patterns and temporal changes in human behaviors and concentrations of contaminants; yet the temporal dimension is often under-emphasized in exposure assessment endeavors, due in part to insufficient tools for visualizing and examining temporal datasets. Spatio-temporal visualization tools are valuable for integrating a temporal component, thus allowing for examination of continuous exposure histories in environmental epidemiologic investigations. An application of these tools to a bladder cancer case-control study in Michigan illustrates continuous exposure life-lines and maps that display smooth, continuous changes over time. Preliminary results suggest increased risk of bladder cancer from combined exposure to arsenic in drinking water (>25 μg/day) and heavy smoking (>30 cigarettes/day) in the 1970s and 1980s, and a possible cancer cluster around automotive, paint, and organic chemical industries in the early 1970s. These tools have broad application for examining spatially- and temporally-specific relationships between exposures to environmental risk factors and disease.

Risk factors for human rabies in China.

PubMed

Gong, Z; He, F; Chen, Z

2012-02-01

In China, we have witnessed an increasing incidence of rabies in recent years and the number of deaths ranked first among the 39 notifiable infectious diseases. We conducted a case-control study to identify risk factors for human rabies infection and disease to recommend prevention and treatment among people exposed to rabies. Exposure site, pre-exposure prophylaxis and post-exposure prophylaxis were significantly associated with rabies infection. Exposure site at upper limb and trunk or at lower limb were at lower risk as compared with head-exposed patients. The OR was 0.09(95% CI: 0.009-0.93) and 0.01(95% CI: 0.001-0.115) respectively. Pre-exposure prophylaxis (OR = 0.05, 95% CI: 0.03-0.11) and post-exposure prophylaxis (OR = 0.02, 95% CI: 0.01-0.40) were both protective factors as compared with no prophylaxis. For patients who had post-exposure prophylaxis, dose for the first injection and immunity procedure were significantly associated with rabies infection. © 2011 Blackwell Verlag GmbH.

Environmental radon exposure and childhood leukemia.

PubMed

Tong, Jian; Qin, Liqiang; Cao, Yi; Li, Jianxiang; Zhang, Jie; Nie, Jihua; An, Yan

2012-01-01

Despite the fact that animal and human epidemiological studies confirmed a link between radon exposure in homes and increased risk of lung cancer in general population, other types of cancers induced by radon, such as leukemia, have not been consistently demonstrated. The aim of this review was to summarize data published thus far from ecological and case-control studies in exposed populations, taking into account radon dose estimation and evidence of radon-induced genotoxicity, in an effort to clarify the correlation between home radon exposure and incidence of childhood leukemia. Among 12 ecological studies, 11 reported a positive association between radon levels and elevated frequency of childhood leukemia, with 8 being significant. In conjunction with ecological studies, several case-control studies on indoor radon exposure and childhood leukemia were examined, and most investigations indicated a weak association with only a few showing significance. A major source of uncertainty in radon risk assessment is radon dose estimate. Methods for radon exposure measurement in homes of children are one of the factors that affect the risk estimates in a case-control study. The effects of radon-induced genetic damage were studied both in vitro and in vivo using genetic endpoints including chromosomal aberration (CA), micronuclei (MN) formation, gene mutation, and deletions and insertions. By applying a meta-analysis, an increased risk of childhood leukemia induced by indoor radon exposure was noted for overall leukemia and for acute lymphoblastic leukemia (ALL). Data thus indicated an association between environmental radon exposure and elevated leukemia incidence, but more evidence is required in both human investigations and animal mechanistic research before this assumption may be confirmed with certainty.

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.

Human Plant Exposures Reported to a Regional (Southwestern) Poison Control Center Over 8 Years.

PubMed

Enfield, Ben; Brooks, Daniel E; Welch, Sharyn; Roland, Maureen; Klemens, Jane; Greenlief, Kim; Olson, Rachel; Gerkin, Richard D

2018-03-01

There is little published data about human plant exposures reported to US poison control centers (PCCs). A retrospective chart review of all reported plant exposures to a single regional PCC between January 1, 2003 and December 31, 2010 was done to understand better the characteristics of plant exposure cases. Specific generic plant codes were used to identify cases. Recorded variables included patient demographics, plant involved, exposure variables, symptoms, management site, treatments, and outcome. Univariate and multivariate regression was used to identify outcome predictors. A total of 6492 charts met inclusion criteria. The average age was 16.6 years (2 months-94 years); 52.4% were male. The most common exposure reason was unintentional (98%), and the majority (92.4%) occurred at the patient's home. Ingestions (58.3%) and dermal exposures (34.3%) accounted for most cases. Cactus (27.5%), oleander (12.5%), Lantana (5.7%), and Bougainvillea (3.8%) were most commonly involved. Symptoms developed in 47.1% of patients, and were more likely to occur following Datura (66.7%), and Morning Glory or Milkweed (25% each) exposures. Almost 94% of patients were managed onsite (home) and only 5.2% involved evaluation in a health care facility (HCF). Only 37 (0.6%) patients required hospital admission, and 2.9% of cases resulted in more than minimal effects. Exposures resulting in more than minimal clinical effects were predicted by several variables: abnormal vital signs (OR = 35.62), abnormal labs (OR = 14.87), and management at a HCF (OR = 7.37). Hospital admissions were increased for patients already at a HCF (OR = 54.01), abnormal vital signs (OR = 23.28), and intentional exposures (OR = 14.7). Plant exposures reported to our poison control center were typically unintentional ingestions occurring at home. Most patients were managed onsite and few developed significant symptoms.

Australian bat lyssavirus: implications for public health.

PubMed

Francis, Joshua R; McCall, Bradley J; Hutchinson, Penny; Powell, Jodie; Vaska, Vikram L; Nourse, Clare

2014-12-11

Australian bat lyssavirus (ABLV) infection in humans is rare but fatal, with no proven effective therapy. ABLV infection can be prevented by administration of a post-exposure prophylaxis regimen of human rabies immunoglobulin and rabies vaccine. All Australian bats (flying foxes and microbats) should be considered to be carrying ABLV unless proven otherwise. Any bat-related injury (bite, scratch or mucosal exposure to bat saliva or neural tissue) should be notified immediately to the relevant public health unit - no matter how small the injury or how long ago it occurred. Human-to-human transmission of ABLV has not been reported but is theoretically possible. Standard infection control precautions should be employed when managing patients with suspected or confirmed ABLV infection.

Hypoxic ventilatory sensitivity in men is not reduced by prolonged hyperoxia (Predictive Studies V and VI)

NASA Technical Reports Server (NTRS)

Gelfand, R.; Lambertsen, C. J.; Clark, J. M.; Hopkin, E.

1998-01-01

Potential adverse effects on the O2-sensing function of the carotid body when its cells are exposed to toxic O2 pressures were assessed during investigations of human organ tolerance to prolonged continuous and intermittent hyperoxia (Predictive Studies V and VI). Isocapnic hypoxic ventilatory responses (HVR) were determined at 1.0 ATA before and after severe hyperoxic exposures: 1) continuous O2 breathing at 1.5, 2.0, and 2.5 ATA for 17.7, 9.0, and 5.7 h and 2) intermittent O2 breathing at 2.0 ATA (30 min O2-30 min normoxia) for 14.3 O2 h within 30-h total time. Postexposure curvature of HVR hyperbolas was not reduced compared with preexposure controls. The hyperbolas were temporarily elevated to higher ventilations than controls due to increments in respiratory frequency that were proportional to O2 exposure time, not O2 pressure. In humans, prolonged hyperoxia does not attenuate the hypoxia-sensing function of the peripheral chemoreceptors, even after exposures that approach limits of human pulmonary and central nervous system O2 tolerance. Current applications of hyperoxia in hyperbaric O2 therapy and in subsea- and aerospace-related operations are guided by and are well within these exposure limits.

Prenatal Exposure to Progesterone Affects Sexual Orientation in Humans.

PubMed

Reinisch, June M; Mortensen, Erik Lykke; Sanders, Stephanie A

2017-07-01

Prenatal sex hormone levels affect physical and behavioral sexual differentiation in animals and humans. Although prenatal hormones are theorized to influence sexual orientation in humans, evidence is sparse. Sexual orientation variables for 34 prenatally progesterone-exposed subjects (17 males and 17 females) were compared to matched controls (M age = 23.2 years). A case-control double-blind design was used drawing on existing data from the US/Denmark Prenatal Development Project. Index cases were exposed to lutocyclin (bioidentical progesterone = C 21 H 30 O 2 ; M W : 314.46) and no other hormonal preparation. Controls were matched on 14 physical, medical, and socioeconomic variables. A structured interview conducted by a psychologist and self-administered questionnaires were used to collect data on sexual orientation, self-identification, attraction to the same and other sex, and history of sexual behavior with each sex. Compared to the unexposed, fewer exposed males and females identified as heterosexual and more of them reported histories of same-sex sexual behavior, attraction to the same or both sexes, and scored higher on attraction to males. Measures of heterosexual behavior and scores on attraction to females did not differ significantly by exposure. We conclude that, regardless of sex, exposure appeared to be associated with higher rates of bisexuality. Prenatal progesterone may be an underappreciated epigenetic factor in human sexual and psychosexual development and, in light of the current prevalence of progesterone treatment during pregnancy for a variety of pregnancy complications, warrants further investigation. These data on the effects of prenatal exposure to exogenous progesterone also suggest a potential role for natural early perturbations in progesterone levels in the development of sexual orientation.

Supplement to the Second Addendum (1986) to Air Quality Criteria for Particulate Matter and Sulfur Oxides (1982): Assessment of New Findings on Sulfur Dioxide and Acute Exposure Health Effects in Asthmatic Individuals (1994)

EPA Science Inventory

The present Supplement to the Second Addendum (1986) to the document Air Quality Criteria for Particulate Matter and Sulfur Oxides (1982) focuses on evaluation of newly available controlled human exposure studies of acute (a\\1h) sulfur dioxide (SO2) exposure effects on pulmonary ...

Environmental levels, toxicity and human exposure to tributyltin (TBT)-contaminated marine environment. a review. b_antizar@hotmail.com.

PubMed

Antizar-Ladislao, Blanca

2008-02-01

Tributyltin (TBT) is a toxic chemical used for various industrial purposes such as slime control in paper mills, disinfection of circulating industrial cooling waters, antifouling agents, and the preservation of wood. Due to its widespread use as an antifouling agent in boat paints, TBT is a common contaminant of marine and freshwater ecosystems exceeding acute and chronic toxicity levels. TBT is the most significant pesticide in marine and freshwaters in Europe and consequently its environmental level, fate, toxicity and human exposure are of current concern. Thus, the European Union has decided to specifically include TBT compounds in its list of priority compounds in water in order to control its fate in natural systems, due to their toxic, persistent, bioaccumulative and endocrine disruptive characteristics. Additionally, the International Maritime Organization has called for a global treaty that bans the application of TBT-based paints starting 1 of January 2003, and total prohibition by 1 of January 2008. This paper reviews the state of the science regarding TBT, with special attention paid to the environmental levels, toxicity, and human exposure. TBT compounds have been detected in a number of environmental samples. In humans, organotin compounds have been detected in blood and in the liver. As for other persistent organic pollutants, dietary intake is most probably the main route of exposure to TBT compounds for the general population. However, data concerning TBT levels in foodstuffs are scarce. It is concluded that investigations on experimental toxicity, dietary intake, potential human health effects and development of new sustainable technologies to remove TBT compounds are clearly necessary.

[Threshold values for chemical agents in the light of the REACH regulation].

PubMed

Cavallo, Domenico Maria; Cattaneo, Andrea; Colosio, Claudio; Moretto, Angelo; Carrer, Paolo; Bartolucci, Giovanni Battista

2011-01-01

The European Regulation 1907/2006 (REACH--Registration, Evaluation, Authorization and Restriction of Chemicals) obliges manufacture companies and import chemicals to assess the risks arising from their use and to take the necessary measures to manage the risks identified. The Chemical Safety Report provides an accurate assessment of hazards to human health and the environment necessary to prepare an exposure scenario for the "identified uses" of the substance. An exposure scenario is the set of conditions that describe how the substance is manufactured or used during its life cycle and how the manufacturer or importer controls, or recommends downstream users to control the 'exposure to humans and the environment. Firms therefore need specific skills. The spectrum of toxicological risk is extremely large, the information required in some cases are very complex and undoubtedly require a thorough knowledge in toxicology and environmental industry. The expertise and experience in toxicology of the occupational physician in this case may become useful in the environmental field as well as another familiar figure of relevant importance is the occupational hygienist who develop exposure scenarios for workers and their uses experience for the exposure scenarios for the consumer. It provides an obvious involvement of medical toxicologists and occupational hygienists for public tasks of control and inspection of chemical safety reports and, locally, even the accuracy of risk that arise from this.

Interim Land Use Control Implementation Plan

NASA Technical Reports Server (NTRS)

Applegate, Joseph L.

2014-01-01

This Interim Land Use Control Implementation Plan (LUCIP) has been prepared to inform current and potential future users of the Kennedy Space Center (KSC) Contractors Road Heavy Equipment (CRHE) Area (SWMU 055; "the Site") of institutional controls that have been implemented at the Site1. Although there are no current unacceptable risks to human health or the environment associated with the CRHE Area, an interim institutional land use control (LUC) is necessary to prevent human health exposure to volatile organic compound (VOC)-affected groundwater at the Site. Controls will include periodic inspection, condition certification, and agency notification.

Directed Differentiation of Human Embryonic Stem Cells into Prostate Organoids In Vitro and its Perturbation by Low-Dose Bisphenol A Exposure

PubMed Central

Calderon-Gierszal, Esther L.; Prins, Gail S.

2015-01-01

Studies using rodent and adult human prostate stem-progenitor cell models suggest that developmental exposure to the endocrine disruptor Bisphenol-A (BPA) can predispose to prostate carcinogenesis with aging. Unknown at present is whether the embryonic human prostate is equally susceptible to BPA during its natural developmental window. To address this unmet need, we herein report the construction of a pioneer in vitro human prostate developmental model to study the effects of BPA. The directed differentiation of human embryonic stem cells (hESC) into prostatic organoids in a spatial system was accomplished with precise temporal control of growth factors and steroids. Activin-induced definitive endoderm was driven to prostate specification by combined exposure to WNT10B and FGF10. Matrigel culture for 20–30 days in medium containing R-Spondin-1, Noggin, EGF, retinoic acid and testosterone was sufficient for mature prostate organoid development. Immunofluorescence and gene expression analysis confirmed that organoids exhibited cytodifferentiation and functional properties of the human prostate. Exposure to 1 nM or 10 nM BPA throughout differentiation culture disturbed early morphogenesis in a dose-dependent manner with 1 nM BPA increasing and 10 nM BPA reducing the number of branched structures formed. While differentiation of branched structures to mature organoids seemed largely unaffected by BPA exposure, the stem-like cell population increased, appearing as focal stem cell nests that have not properly entered lineage commitment rather than the rare isolated stem cells found in normally differentiated structures. These findings provide the first direct evidence that low-dose BPA exposure targets hESC and perturbs morphogenesis as the embryonic cells differentiate towards human prostate organoids, suggesting that the developing human prostate may be susceptible to disruption by in utero BPA exposures. PMID:26222054

Creatinine elevation associated with nitromethane exposure: a marker of potential methanol toxicity.

PubMed

Cook, Matthew D; Clark, Richard F

2007-10-01

Nitromethane, methanol, and oil are the common components of radio-controlled (R/C) vehicle fuels. Nitromethane can cause a false elevation of serum creatinine concentration as measured by the widely used Jaffe colorimetric method. We gathered data from our poison control system and from previously published case reports to see if a correlation exists between serum methanol concentrations and spuriously elevated serum creatinine concentrations after human exposures to R/C fuel. The California Poison Control System (CPCS) computerized database was queried for all cases of human exposure to R/C vehicle fuel reported between December 1, 2002 and December 1, 2004. Serum creatinine and methanol concentrations were recorded when available, as was the method used to determine serum creatinine. A MEDLINE search was used to obtain previously published cases of human nitromethane exposure associated with falsely elevated creatinine concentrations. During the 2-year period, serum creatinine concentrations were recorded in 7 of 26 R/C fuel exposures (all ingestions), and 6 of these were abnormal (range of 1.9-11.5 mg/dL). In this series, the higher the serum creatinine concentration measured by Jaffe method, the higher the serum methanol concentration. The MEDLINE search yielded data from six previously published case reports on this topic. The data from these case reports seem to follow the trend seen in our case series. These data suggest that a spuriously elevated serum creatinine (by Jaffe method) may have value as an early surrogate marker of methanol poisoning in those who ingest R/C fuel. Also, the degree to which the serum creatinine is elevated may indicate the severity of methanol poisoning.

Effect of surface functionalizations of multi-walled carbon nanotubes on neoplastic transformation potential in primary human lung epithelial cells.

PubMed

Stueckle, Todd A; Davidson, Donna C; Derk, Ray; Wang, Peng; Friend, Sherri; Schwegler-Berry, Diane; Zheng, Peng; Wu, Nianqiang; Castranova, Vince; Rojanasakul, Yon; Wang, Liying

2017-06-01

Functionalized multi-walled carbon nanotube (fMWCNT) development has been intensified to improve their surface activity for numerous applications, and potentially reduce toxic effects. Although MWCNT exposures are associated with lung tumorigenesis in vivo, adverse responses associated with exposure to different fMWCNTs in human lung epithelium are presently unknown. This study hypothesized that different plasma-coating functional groups determine MWCNT neoplastic transformation potential. Using our established model, human primary small airway epithelial cells (pSAECs) were continuously exposed for 8 and 12 weeks at 0.06 μg/cm 2 to three-month aged as-prepared-(pMWCNT), carboxylated-(MW-COOH), and aminated-MWCNTs (MW-NH x ). Ultrafine carbon black (UFCB) and crocidolite asbestos (ASB) served as particle controls. fMWCNTs were characterized during storage, and exposed cells were assessed for several established cancer cell hallmarks. Characterization analyses conducted at 0 and 2 months of aging detected a loss of surface functional groups over time due to atmospheric oxidation, with MW-NH x possessing less oxygen and greater lung surfactant binding affinity. Following 8 weeks of exposure, all fMWCNT-exposed cells exhibited significant increased proliferation compared to controls at 7 d post-treatment, while UFCB- and ASB-exposed cells did not differ significantly from controls. UFCB, pMWCNT, and MW-COOH exposure stimulated significant transient invasion behavior. Conversely, aged MW-NH x -exposed cells displayed moderate increases in soft agar colony formation and morphological transformation potential, while UFCB cells showed a minimal effect compared to all other treatments. In summary, surface properties of aged fMWCNTs can impact cell transformation events in vitro following continuous, occupationally relevant exposures.

Fighting rabies in Eastern Europe, the Middle East and Central Asia--experts call for a regional initiative for rabies elimination.

PubMed

Aikimbayev, A; Briggs, D; Coltan, G; Dodet, B; Farahtaj, F; Imnadze, P; Korejwo, J; Moiseieva, A; Tordo, N; Usluer, G; Vodopija, R; Vranješ, N

2014-05-01

MEEREB is an informal network of rabies experts from the Middle East, Eastern Europe and Central Asia, seeking to eliminate rabies from the region. They met for the second time to review the current rabies situation, both globally and in their respective countries, highlighting current rabies control problems and potential solutions. Success stories in Latin America, in Western Europe, in some Asian countries, as well as in Croatia and Serbia prove that elimination of human rabies is achievable in the MEEREB region. It requires political willingness and cooperation of all stakeholders, including Ministries of Health and of Agriculture; adequate management of animal bites through post-exposure prophylaxis; pre-exposure prophylaxis for populations at high risk of rabies exposure, animal vaccination and humane control of stray dog populations. MEEREB members called for a regional initiative for rabies elimination in Eastern Europe and the Middle East. They are confident that the elimination of human rabies of canine origin can be achieved in the region through adopting a One Health approach, and that campaigns for rabies elimination will have significant benefit for public health, including strengthening the structure for control of other zoonoses. © 2013 Blackwell Verlag GmbH.

Drinking-water arsenic exposure modulates gene expression in human lymphocytes from a U.S. population.

PubMed

Andrew, Angeline S; Jewell, David A; Mason, Rebecca A; Whitfield, Michael L; Moore, Jason H; Karagas, Margaret R

2008-04-01

Arsenic exposure impairs development and can lead to cancer, cardiovascular disease, and diabetes. The mechanism underlying these effects remains unknown. Primarily because of geologic sources of contamination, drinking-water arsenic levels are above the current recommended maximum contaminant level of 10 microg/L in the northeastern, western, and north central regions of the United States. We investigated the effects of arsenic exposure, defined by internal biomarkers at levels relevant to the United States and similarly exposed populations, on gene expression. We conducted separate Affymetrix microarray-based genomewide analyses of expression patterns. Peripheral blood lymphocyte samples from 21 controls interviewed (1999-2002) as part of a case-control study in New Hampshire were selected based on high- versus low-level arsenic exposure levels. The biologic functions of the transcripts that showed statistically significant abundance differences between high- and low-arsenic exposure groups included an overrepresentation of genes involved in defense response, immune function, cell growth, apoptosis, regulation of cell cycle, T-cell receptor signaling pathway, and diabetes. Notably, the high-arsenic exposure group exhibited higher levels of several killer cell immunoglobulin-like receptors that inhibit natural killer cell activity. These findings define biologic changes that occur with chronic arsenic exposure in humans and provide leads and potential targets for understanding and monitoring the pathogenesis of arsenic-induced diseases.

Induction of genomic instability in TK6 human lymphoblasts exposed to 137Cs gamma radiation: comparison to the induction by exposure to accelerated 56Fe particles

NASA Technical Reports Server (NTRS)

Evans, Helen H.; Horng, Min-Fen; Ricanati, Marlene; Diaz-Insua, M.; Jordan, Robert; Schwartz, Jeffrey L.

2003-01-01

The induction of genomic instability in TK6 human lymphoblasts by exposure to (137)Cs gamma radiation was investigated by measuring the frequency and characteristics of unstable clones isolated approximately 36 generations after exposure. Clones surviving irradiation and control clones were analyzed for 17 characteristics including chromosomal aberrations, growth defects, alterations in response to a second irradiation, and mutant frequencies at the thymidine kinase and Na(+)/K(+) ATPase loci. Putative unstable clones were defined as those that exhibited a significant alteration in one or more characteristics compared to the controls. The frequency and characteristics of the unstable clones were compared in clones exposed to (137)Cs gamma rays or (56)Fe particles. The majority of the unstable clones isolated after exposure to either gamma rays or (56)Fe particles exhibited chromosomal instability. Alterations in growth characteristics, radiation response and mutant frequencies occurred much less often than cytogenetic alterations in these unstable clones. The frequency and complexity of the unstable clones were greater after exposure to (56)Fe particles than to gamma rays. Unstable clones that survived 36 generations after exposure to gamma rays exhibited increases in the incidence of dicentric chromosomes but not of chromatid breaks, whereas unstable clones that survived 36 generations after exposure to (56)Fe particles exhibited increases in both chromatid and chromosome aberrations.

Mass spectrometry profiling of oxylipins, endocannabinoids, and N-acylethanolamines in human lung lavage fluids reveals responsiveness of prostaglandin E2 and associated lipid metabolites to biodiesel exhaust exposure.

PubMed

Gouveia-Figueira, Sandra; Karimpour, Masoumeh; Bosson, Jenny A; Blomberg, Anders; Unosson, Jon; Pourazar, Jamshid; Sandström, Thomas; Behndig, Annelie F; Nording, Malin L

2017-04-01

The adverse effects of petrodiesel exhaust exposure on the cardiovascular and respiratory systems are well recognized. While biofuels such as rapeseed methyl ester (RME) biodiesel may have ecological advantages, the exhaust generated may cause adverse health effects. In the current study, we investigated the responses of bioactive lipid mediators in human airways after biodiesel exhaust exposure using lipidomic profiling methods. Lipid mediator levels in lung lavage were assessed following 1-h biodiesel exhaust (average particulate matter concentration, 159 μg/m 3 ) or filtered air exposure in 15 healthy individuals in a double-blinded, randomized, controlled, crossover study design. Bronchoscopy was performed 6 h post exposure and lung lavage fluids, i.e., bronchial wash (BW) and bronchoalveolar lavage (BAL), were sequentially collected. Mass spectrometry methods were used to detect a wide array of oxylipins (including eicosanoids), endocannabinoids, N-acylethanolamines, and related lipid metabolites in the collected BW and BAL samples. Six lipids in the human lung lavage samples were altered following biodiesel exhaust exposure, three from BAL samples and three from BW samples. Of these, elevated levels of PGE 2 , 12,13-DiHOME, and 13-HODE, all of which were found in BAL samples, reached Bonferroni-corrected significance. This is the first study in humans reporting responses of bioactive lipids following biodiesel exhaust exposure and the most pronounced responses were seen in the more peripheral and alveolar lung compartments, reflected by BAL collection. Since the responsiveness and diagnostic value of a subset of the studied lipid metabolites were established in lavage fluids, we conclude that our mass spectrometry profiling method is useful to assess effects of human exposure to vehicle exhaust.

Epidemiology, Impact and Control of Rabies in Nepal: A Systematic Review.

PubMed

Devleesschauwer, Brecht; Aryal, Arjun; Sharma, Barun Kumar; Ale, Anita; Declercq, Anne; Depraz, Stephanie; Gaire, Tara Nath; Gongal, Gyanendra; Karki, Surendra; Pandey, Basu Dev; Pun, Sher Bahadur; Duchateau, Luc; Dorny, Pierre; Speybroeck, Niko

2016-02-01

Rabies is a vaccine-preventable viral zoonosis belonging to the group of neglected tropical diseases. Exposure to a rabid animal may result in a fatal acute encephalitis if effective post-exposure prophylaxis is not provided. Rabies occurs worldwide, but its burden is disproportionately high in developing countries, including Nepal. We aimed to summarize current knowledge on the epidemiology, impact and control of rabies in Nepal. We performed a systematic review of international and national scientific literature and searched grey literature through the World Health Organization Digital Library and the library of the National Zoonoses and Food Hygiene Research Centre, Nepal, and through searching Google and Google Scholar. Further data on animal and human rabies were obtained from the relevant Nepalese government agencies. Finally, we surveyed the archives of a Nepalese daily to obtain qualitative information on rabies in Nepal. So far, only little original research has been conducted on the epidemiology and impact of rabies in Nepal. Per year, rabies is reported to kill about 100 livestock and 10-100 humans, while about 1,000 livestock and 35,000 humans are reported to receive rabies post-exposure prophylaxis. However, these estimates are very likely to be serious underestimations of the true rabies burden. Significant progress has been made in the production of cell culture-based anti-rabies vaccine and rabies immunoglobulin, but availability and supply remain a matter of concern, especially in remote areas. Different state and non-state actors have initiated rabies control activities over the years, but efforts typically remained focalized, of short duration and not harmonized. Communication and coordination between veterinary and human health authorities is limited at present, further complicating rabies control in Nepal. Important research gaps include the reporting biases for both human and animal rabies, the ecology of stray dog populations and the true contribution of the sylvatic cycle. Better data are needed to unravel the true burden of animal and human rabies. More collaboration, both within the country and within the region, is needed to control rabies. To achieve these goals, high level political commitment is essential. We therefore propose to make rabies the model zoonosis for successful control in Nepal.

Factors that are associated with the risk of acquiring Plasmodium knowlesi malaria in Sabah, Malaysia: a case-control study protocol

PubMed Central

Grigg, M J; William, T; Drakeley, C J; Jelip, J; von Seidlein, L; Barber, B E; Fornace, K M; Anstey, N M; Yeo, T W; Cox, J

2014-01-01

Introduction Plasmodium knowlesi has long been present in Malaysia, and is now an emerging cause of zoonotic human malaria. Cases have been confirmed throughout South-East Asia where the ranges of its natural macaque hosts and Anopheles leucosphyrus group vectors overlap. The majority of cases are from Eastern Malaysia, with increasing total public health notifications despite a concurrent reduction in Plasmodium falciparum and P. vivax malaria. The public health implications are concerning given P. knowlesi has the highest risk of severe and fatal disease of all Plasmodium spp in Malaysia. Current patterns of risk and disease vary based on vector type and competence, with individual exposure risks related to forest and forest-edge activities still poorly defined. Clustering of cases has not yet been systematically evaluated despite reports of peri-domestic transmission and known vector competence for human-to-human transmission. Methods and analysis A population-based case–control study will be conducted over a 2-year period at two adjacent districts in north-west Sabah, Malaysia. Confirmed malaria cases presenting to the district hospital sites meeting relevant inclusion criteria will be requested to enrol. Three community controls matched to the same village as the case will be selected randomly. Study procedures will include blood sampling and administration of household and individual questionnaires to evaluate potential exposure risks associated with acquisition of P. knowlesi malaria. Secondary outcomes will include differences in exposure variables between P. knowlesi and other Plasmodium spp, risk of severe P. knowlesi malaria, and evaluation of P. knowlesi case clustering. Primary analysis will be per protocol, with adjusted ORs for exposure risks between cases and controls calculated using conditional multiple logistic regression models. Ethics This study has been approved by the human research ethics committees of Malaysia, the Menzies School of Health Research, Australia, and the London School of Hygiene and Tropical Medicine, UK. PMID:25149186

Human IgG Antibody Response to Aedes Nterm-34kDa Salivary Peptide, an Epidemiological Tool to Assess Vector Control in Chikungunya and Dengue Transmission Area

PubMed Central

Elanga Ndille, Emmanuel; Doucoure, Souleymane; Poinsignon, Anne; Mouchet, François; Cornelie, Sylvie; D’Ortenzio, Eric; DeHecq, Jean Sébastien; Remoue, Franck

2016-01-01

Background Arboviral diseases are an important public health concerns. Vector control remains the sole strategy to fight against these diseases. Because of the important limits of methods currently used to assess human exposure to Aedes mosquito bites, much effort is being devoted to develop new indicators. Recent studies have reported that human antibody (Ab) responses to Aedes aegypti Nterm-34kDa salivary peptide represent a promising biomarker tool to evaluate the human-Aedes contact. The present study aims investigate whether such biomarker could be used for assessing the efficacy of vector control against Aedes. Methodology/Principal findings Specific human IgG response to the Nterm-34kDa peptide was assessed from 102 individuals living in urban area of Saint-Denis at La Reunion Island, Indian Ocean, before and after the implementation of vector control against Aedes mosquitoes. IgG response decreased after 2 weeks (P < 0.0001), and remained low for 4 weeks post-intervention (P = 0.0002). The specific IgG decrease was associated with the decline of Aedes mosquito density, as estimated by entomological parameters and closely correlated to vector control implementation and was not associated with the use of individual protection, daily commuting outside of the house, sex and age. Our findings indicate a probable short-term decrease of human exposure to Aedes bites just after vector control implementation. Conclusion/Significance Results provided in the present study indicate that IgG Ab response to Aedes aegypti Nterm-34kDa salivary peptide could be a relevant short-time indicator for evaluating the efficacy of vector control interventions against Aedes species. PMID:27906987

Human IgG Antibody Response to Aedes Nterm-34kDa Salivary Peptide, an Epidemiological Tool to Assess Vector Control in Chikungunya and Dengue Transmission Area.

PubMed

Elanga Ndille, Emmanuel; Doucoure, Souleymane; Poinsignon, Anne; Mouchet, François; Cornelie, Sylvie; D'Ortenzio, Eric; DeHecq, Jean Sébastien; Remoue, Franck

2016-12-01

Arboviral diseases are an important public health concerns. Vector control remains the sole strategy to fight against these diseases. Because of the important limits of methods currently used to assess human exposure to Aedes mosquito bites, much effort is being devoted to develop new indicators. Recent studies have reported that human antibody (Ab) responses to Aedes aegypti Nterm-34kDa salivary peptide represent a promising biomarker tool to evaluate the human-Aedes contact. The present study aims investigate whether such biomarker could be used for assessing the efficacy of vector control against Aedes. Specific human IgG response to the Nterm-34kDa peptide was assessed from 102 individuals living in urban area of Saint-Denis at La Reunion Island, Indian Ocean, before and after the implementation of vector control against Aedes mosquitoes. IgG response decreased after 2 weeks (P < 0.0001), and remained low for 4 weeks post-intervention (P = 0.0002). The specific IgG decrease was associated with the decline of Aedes mosquito density, as estimated by entomological parameters and closely correlated to vector control implementation and was not associated with the use of individual protection, daily commuting outside of the house, sex and age. Our findings indicate a probable short-term decrease of human exposure to Aedes bites just after vector control implementation. Results provided in the present study indicate that IgG Ab response to Aedes aegypti Nterm-34kDa salivary peptide could be a relevant short-time indicator for evaluating the efficacy of vector control interventions against Aedes species.

Asbestos: The Need for and Feasibility of Air Pollution Controls.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Div. of Medical Sciences.

The monograph presents a brief summary of the problems associated with airborne asbestos. It discusses the evidence regarding the pathogenicity of asbestos in man and animals, considers the evidence of human non-occupational exposure to asbestos, evaluates the evidence regarding health risks associated with various degrees and types of exposure,…

Mapping the future: U.S. exposure to multiple landscape stressors

Treesearch

Marie Oliver; Becky Kerns; John Kim; Jeff Kline

2017-01-01

Landscape exposure to multiple stressors can pose risks to human health, biodiversity, and ecosystem services. Attempts to study, control, or mitigate these stressors can strain public and private budgets. An interdisciplinary team of Pacific Northwest Research Station and Oregon State University scientists created maps of the conterminous United States that indicate...

Model Bloodborne Pathogens: Exposure Control Plan for Wisconsin Public Schools. Bulletin No. 93311.

ERIC Educational Resources Information Center

Wisconsin State Dept. of Public Instruction, Madison.

This document is intended to assist local school districts in complying with the Wisconsin Department of Industry, Labor and Human Relations (DILHR) Health and Safety Standard. Following an overview of the plan, the guide is organized into six chapters: (1) "Exposure Determination" discusses job classifications, tasks, and procedures;…

Polycyclic Aromatic Hydrocarbons and Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans in Microliter Samples of Human Serum as Exposure Indicators

PubMed Central

Xia, Xiaoyan; Carroll-Haddad, Alesia; Brown, Nicole; Utell, Mark J.; Mallon, Timothy; Hopke, Philip K.

2016-01-01

Objective The objectives were: 1) measure polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in 100 μL of human serum and 2) assess PAH and PCDD/PCDF as markers of burn pit exposures during military deployments. Methods PAHs and PCDDs/PCDFs were analyzed in 100μL serum samples collected pre- and post-deployment from 200 persons deployed to Iraq or Afghanistan (CASE); 200 persons not deployed (CONTROL) with GC/MS. Results Naphthalene was found in ~83% of the samples and was statistically different between post-deployment CASE personnel and pre-deployment. 1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin, Octachlorodibenzo-p-dioxin, 1,2,3,7,8,9-Hexachlorodibenzofuran, and 1,2,3,4,6,7,8-Heptachlorodibenzofuran were found in ~38% of samples. Concentrations were significantly different between CASE and CONTROL and between pre- and post-deployment samples. Conclusions PAH and PCDD/PCDF in serum can serve as exposure markers and measurements in small volumes is feasible for quantifying exposure to burn pits. PMID:27501107

Critical Evaluation of the Linkage Between Tick-Based Risk Measures and the Occurrence of Lyme Disease Cases.

PubMed

Eisen, Lars; Eisen, Rebecca J

2016-06-21

The nymphal stage of the blacklegged tick, Ixodes scapularis Say, is considered the primary vector to humans in the eastern United States of the Lyme disease spirochete Borrelia burgdorferi sensu stricto. The abundance of infected host-seeking nymphs is commonly used to estimate the fundamental risk of human exposure to B. burgdorferi, for the purpose of environmental risk assessment and as an outcome measure when evaluating environmentally based tick or pathogen control methods. However, as this tick-based risk measure does not consider the likelihoods of either human encounters with infected ticks or tick bites resulting in pathogen transmission, its linkage to the occurrence of Lyme disease cases is worth evaluating. In this Forum article, we describe different tick-based risk measures, discuss their strengths and weaknesses, and review the evidence for their capacity to predict the occurrence of Lyme disease cases. We conclude that: 1) the linkage between abundance of host-seeking B. burgdorferi-infected nymphs and Lyme disease occurrence is strong at community or county scales but weak at the fine spatial scale of residential properties where most human exposures to infected nymphs occur in Northeast, 2) the combined use of risk measures based on infected nymphs collected from the environment and ticks collected from humans is preferable to either one of these risk measures used singly when assessing the efficacy of environmentally based tick or pathogen control methods aiming to reduce the risk of human exposure to B. burgdorferi, 3) there is a need for improved risk assessment methodology for residential properties that accounts for both the abundance of infected nymphs and the likelihood of human-tick contact, and 4) we need to better understand how specific human activities conducted in defined residential microhabitats relate to risk for nymphal exposures and bites. Published by Oxford University Press on behalf of Entomological Society of America 2016.This work is written by US Government employees and is in the public domain in the US.

Late-life effects on rat reproductive system after developmental exposure to mixtures of endocrine disrupters.

PubMed

Isling, Louise Krag; Boberg, Julie; Jacobsen, Pernille Rosenskjold; Mandrup, Karen Riiber; Axelstad, Marta; Christiansen, Sofie; Vinggaard, Anne Marie; Taxvig, Camilla; Kortenkamp, Andreas; Hass, Ulla

2014-01-01

This study examined late-life effects of perinatal exposure of rats to a mixture of endocrine-disrupting contaminants. Four groups of 14 time-mated Wistar rats were exposed by gavage from gestation day 7 to pup day 22 to a mixture of 13 anti-androgenic and estrogenic chemicals including phthalates, pesticides, u.v.-filters, bisphenol A, parabens, and the drug paracetamol. The groups received vehicle (control), a mixture of all 13 chemicals at 150-times (TotalMix150) or 450-times (TotalMix450) high-end human exposure, or 450-times a mixture of nine predominantly anti-androgenic chemicals (AAMix450). Onset of puberty and estrous cyclicity at 9 and 12 months of age were assessed. Few female offspring showed significantly regular estrus cyclicity at 12 months of age in the TotalMix450 and AAMix450 groups compared with controls. In 19-month-old male offspring, epididymal sperm counts were lower than controls, and in ventral prostate an overrepresentation of findings related to hyperplasia was observed in exposed groups compared with controls, particularly in the group dosed with anti-androgens. A higher incidence of pituitary adenoma at 19 months of age was found in males and females in the AAMix450 group. Developmental exposure of rats to the highest dose of a human-relevant mixture of endocrine disrupters induced adverse effects late in life, manifested as earlier female reproductive senescence, reduced sperm counts, higher score for prostate atypical hyperplasia, and higher incidence of pituitary tumors. These delayed effects highlight the need for further studies on the role of endocrine disrupters in hormone-related disorders in aging humans.

Using Biomarkers in Sewage to Monitor Community-Wide Human Health: Isoprostances as Conceptual Prototype

EPA Science Inventory

Timely assessment of the aggregate health of small-area human populations is essential for guiding the optimal investment of resources needed for preventing, avoiding, controlling, or mitigating exposure risks. Seeking those interventions yielding the greatest benefit with respec...

New Exposure Biomarkers as Tools for Breast Cancer Epidemiology, Biomonitoring, and Prevention: A Systematic Approach Based on Animal Evidence

PubMed Central

Ackerman, Janet M.; Attfield, Kathleen R.; Brody, Julia Green

2014-01-01

Background: Exposure to chemicals that cause rodent mammary gland tumors is common, but few studies have evaluated potential breast cancer risks of these chemicals in humans. Objective: The goal of this review was to identify and bring together the needed tools to facilitate the measurement of biomarkers of exposure to potential breast carcinogens in breast cancer studies and biomonitoring. Methods: We conducted a structured literature search to identify measurement methods for exposure biomarkers for 102 chemicals that cause rodent mammary tumors. To evaluate concordance, we compared human and animal evidence for agents identified as plausibly linked to breast cancer in major reviews. To facilitate future application of exposure biomarkers, we compiled information about relevant cohort studies. Results: Exposure biomarkers have been developed for nearly three-quarters of these rodent mammary carcinogens. Analytical methods have been published for 73 of the chemicals. Some of the remaining chemicals could be measured using modified versions of existing methods for related chemicals. In humans, biomarkers of exposure have been measured for 62 chemicals, and for 45 in a nonoccupationally exposed population. The Centers for Disease Control and Prevention has measured 23 in the U.S. population. Seventy-five of the rodent mammary carcinogens fall into 17 groups, based on exposure potential, carcinogenicity, and structural similarity. Carcinogenicity in humans and rodents is generally consistent, although comparisons are limited because few agents have been studied in humans. We identified 44 cohort studies, with a total of > 3.5 million women enrolled, that have recorded breast cancer incidence and stored biological samples. Conclusions: Exposure measurement methods and cohort study resources are available to expand biomonitoring and epidemiology related to breast cancer etiology and prevention. Citation: Rudel RA, Ackerman JM, Attfield KR, Brody JG. 2014. New exposure biomarkers as tools for breast cancer epidemiology, biomonitoring, and prevention: a systematic approach based on animal evidence. Environ Health Perspect 122:881–895; http://dx.doi.org/10.1289/ehp.1307455 PMID:24818537

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

Risk Factors for Human Salmonellosis Originating from Pigs, Cattle, Broiler Chickens and Egg Laying Hens: A Combined Case-Control and Source Attribution Analysis

PubMed Central

Mughini-Gras, Lapo; Enserink, Remko; Friesema, Ingrid; Heck, Max; van Duynhoven, Yvonne; van Pelt, Wilfrid

2014-01-01

Several case-control studies have investigated risk factors for human salmonellosis while others have used Salmonella subtyping to attribute human infections to different food and animal reservoirs. This study combined case-control and source attribution data into a single analysis to explore risk factors at the point of exposure for human salmonellosis originating from four putative food-producing animal reservoirs (pigs, cattle, broilers and layers/eggs) in the Netherlands. We confirmed that most human cases (∼90%) were attributable to layers/eggs and pigs. Layers/eggs and broilers were the most likely reservoirs of salmonellosis in adults, in urban areas, and in spring/summer, whereas pigs and cattle were the most likely reservoirs of salmonellosis in children, in rural areas, and in autumn/winter. Several reservoir-specific risk factors were identified. Not using a chopping board for raw meat only and consuming raw/undercooked meat were risk factors for infection with salmonellas originating from pigs, cattle and broilers. Consuming raw/undercooked eggs and by-products were risk factors for layer/egg-associated salmonellosis. Using antibiotics was a risk factor for pig- and cattle-associated salmonellosis and using proton-pump inhibitors for salmonellosis attributable to any reservoir. Pig- and cattle-associated infections were also linked to direct contact with animals and environmental exposure (e.g. playing in sandboxes). Eating fish, meat in pastry, and several non-meat foods (fruit, vegetables and pasteurized dairy products) were protective factors. Consuming pork and occupational exposure to animals and/or raw meats were protective against layer/egg-associated salmonellosis. We concluded that individuals acquiring salmonellosis from different reservoirs have different associated risk factors, suggesting that salmonellas may infect humans through various transmission pathways depending on their original reservoirs. The outcome of classical case-control studies can be enhanced by incorporating source attribution data and vice versa. PMID:24503703

Exposure of the Bone Marrow Microenvironment to Simulated Solar and Galactic Cosmic Radiation Induces Biological Bystander Effects on Human Hematopoiesis

DOE PAGES

Almeida-Porada, Graca; Rodman, Christopher; Kuhlman, Bradford; ...

2018-04-26

The stem cell compartment of the hematopoietic system constitutes one of the most radiosensitive tissues of the body and leukemias represent one of the most frequent radiogenic cancers with short latency periods. As such, leukemias may pose a particular threat to astronauts during prolonged space missions. Control of hematopoiesis is tightly governed by a specialized bone marrow (BM) microenvironment/niche. As such, any environmental insult that damages cells of this niche would be expected to produce pronounced effects on the types and functionality of hematopoietic/immune cells generated. We recently reported that direct exposure of human HSC to simulated SEP and GCRmore » radiation dramatically altered the differentiative potential of these cells, and that simulated GCR exposures can directly induce DNA damage and mutations within human HSC, which led to leukemic transformation when these cells repopulated murine recipients. In the present study, we performed the first in depth examination to define changes that occur in mesenchymal stem cells (MSC) present in the human BM niche following exposure to accelerated protons and iron ions, and assess the impact these changes have upon human hematopoiesis. Here, our data thus provides compelling evidence that simulated SEP/GCR exposures can also contribute to defective hematopoiesis/immunity through so-called “biological bystander effects” by damaging the stromal cells that comprise the human marrow microenvironment, thereby altering their ability to support normal hematopoiesis.« less

Exposure of the Bone Marrow Microenvironment to Simulated Solar and Galactic Cosmic Radiation Induces Biological Bystander Effects on Human Hematopoiesis

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

Almeida-Porada, Graca; Rodman, Christopher; Kuhlman, Bradford

The stem cell compartment of the hematopoietic system constitutes one of the most radiosensitive tissues of the body and leukemias represent one of the most frequent radiogenic cancers with short latency periods. As such, leukemias may pose a particular threat to astronauts during prolonged space missions. Control of hematopoiesis is tightly governed by a specialized bone marrow (BM) microenvironment/niche. As such, any environmental insult that damages cells of this niche would be expected to produce pronounced effects on the types and functionality of hematopoietic/immune cells generated. We recently reported that direct exposure of human HSC to simulated SEP and GCRmore » radiation dramatically altered the differentiative potential of these cells, and that simulated GCR exposures can directly induce DNA damage and mutations within human HSC, which led to leukemic transformation when these cells repopulated murine recipients. In the present study, we performed the first in depth examination to define changes that occur in mesenchymal stem cells (MSC) present in the human BM niche following exposure to accelerated protons and iron ions, and assess the impact these changes have upon human hematopoiesis. Here, our data thus provides compelling evidence that simulated SEP/GCR exposures can also contribute to defective hematopoiesis/immunity through so-called “biological bystander effects” by damaging the stromal cells that comprise the human marrow microenvironment, thereby altering their ability to support normal hematopoiesis.« less

Exposure of the Bone Marrow Microenvironment to Simulated Solar and Galactic Cosmic Radiation Induces Biological Bystander Effects on Human Hematopoiesis.

PubMed

Almeida-Porada, Graça; Rodman, Christopher; Kuhlman, Bradford; Brudvik, Egil; Moon, John; George, Sunil; Guida, Peter; Sajuthi, Satria P; Langefeld, Carl D; Walker, Stephen J; Wilson, Paul F; Porada, Christopher D

2018-04-26

The stem cell compartment of the hematopoietic system constitutes one of the most radiosensitive tissues of the body and leukemias represent one of the most frequent radiogenic cancers with short latency periods. As such, leukemias may pose a particular threat to astronauts during prolonged space missions. Control of hematopoiesis is tightly governed by a specialized bone marrow (BM) microenvironment/niche. As such, any environmental insult that damages cells of this niche would be expected to produce pronounced effects on the types and functionality of hematopoietic/immune cells generated. We recently reported that direct exposure of human hematopoietic stem cells (HSC) to simulated solar energetic particle (SEP) and galactic cosmic ray (GCR) radiation dramatically altered the differentiative potential of these cells, and that simulated GCR exposures can directly induce DNA damage and mutations within human HSC, which led to leukemic transformation when these cells repopulated murine recipients. In this study, we performed the first in-depth examination to define changes that occur in mesenchymal stem cells present in the human BM niche following exposure to accelerated protons and iron ions and assess the impact these changes have upon human hematopoiesis. Our data provide compelling evidence that simulated SEP/GCR exposures can also contribute to defective hematopoiesis/immunity through so-called "biological bystander effects" by damaging the stromal cells that comprise the human marrow microenvironment, thereby altering their ability to support normal hematopoiesis.

Exposure assessment for trihalomethanes in municipal drinking water and risk reduction strategy.

PubMed

Chowdhury, Shakhawat

2013-10-01

Lifetime exposure to disinfection byproducts (DBPs) in municipal water may pose risks to human health. Current approaches of exposure assessments use DBPs in cold water during showering, while warming of chlorinated water during showering may increase trihalomethane (THM) formation in the presence of free residual chlorine. Further, DBP exposure through dermal contact during showering is estimated using steady-state condition between the DBPs in shower water impacting on human skin and skin exposed to shower water. The lag times to achieve steady-state condition between DBPs in shower water and human skin can vary in the range of 9.8-391.2 min, while shower duration is often less than the lag times. Assessment of exposure without incorporating these factors might have misinterpreted DBP exposure in some previous studies. In this study, exposure to THMs through ingestion was estimated using cold water THMs, while THM exposure through inhalation and dermal contact during showering was estimated using THMs in warm water. Inhalation of THMs was estimated using THM partition into the shower air, while dermal uptake was estimated by incorporating lag times (e.g., unsteady and steady-state phases of exposure) during showering. Probabilistic approach was followed to incorporate uncertainty in the assessment. Inhalation and dermal contact during showering contributed 25-60% of total exposure. Exposure to THMs during showering can be controlled by varying shower stall volume, shower duration and air exchange rate following power law equations. The findings might be useful in understanding exposure to THMs, which can be extended to other volatile compounds in municipal water. © 2013 Elsevier B.V. All rights reserved.

Associations of maternal exposure to triclosan, parabens, and other phenols with prenatal maternal and neonatal thyroid hormone levels.

PubMed

Berger, Kimberly; Gunier, Robert B; Chevrier, Jonathan; Calafat, Antonia M; Ye, Xiaoyun; Eskenazi, Brenda; Harley, Kim G

2018-05-24

Environmental phenols and parabens are commonly used in personal care products and other consumer products and human exposure to these chemicals is widespread. Although human and animal studies suggest an association between exposure to phenols and parabens and thyroid hormone levels, few studies have investigated the association of in utero exposure to these chemicals and thyroid hormones in pregnant women and their neonates. We measured four environmental phenols (triclosan, benzophenone-3, and 2,4- and 2,5-dichlorophenol), and three parabens (methyl-, propyl-, and butyl paraben) in urine collected from mothers at two time points during pregnancy as part of the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study. We measured free thyroxine (T4), total T4, and thyroid-stimulating hormone (TSH) in serum of the pregnant women (N = 454) and TSH in their neonates (N = 365). We examined potential confounding by a large number of additional chemical exposures and used Bayesian Model Averaging (BMA) to select the most influential chemicals to include in regression models. We observed negative associations of prenatal urinary concentrations of propyl paraben and maternal TSH (β for two-fold increase = -3.26%, 95% CI: -5.55, -0.90) and negative associations of 2,4-dichlorophenol and maternal free T4 (β for two-fold increase = -0.05, 95% CI: -0.08, -0.02), after controlling for other chemical exposures. We observed negative associations of triclosan with maternal total T4 after controlling for demographic variables, but this association became non-significant after controlling for other chemicals (β for two-fold increase = -0.05, 95% CI: -0.11, 0.00). We found evidence that environmental phenols and parabens are associated with lower TSH and free T4 in pregnant women after controlling for related chemical exposures. Copyright © 2018 Elsevier Inc. All rights reserved.

Controlling for Selection Effects in the Relationship between Child Behavior Problems and Exposure to Intimate Partner Violence

ERIC Educational Resources Information Center

Emery, Clifton R.

2011-01-01

This article used the Project on Human Development in Chicago Neighborhoods (PHDCN) data to examine the relationship between exposure to intimate partner violence (IPV) and child behavior problems (externalizing and internalizing), truancy, grade repetition, smoking, drinking, and use of marijuana. Longitudinal data analysis was conducted on 1,816…

THE RELATIONSHIP BETWEEN REAL-TIME AND TIME-INTEGRATED COARSE (2.5-10MM), INTERMEDIATE (1-2.5MM), AND FINE (<2.5MM) PARTICULATE MATTER IN THE LOS ANGELES BASIN

EPA Science Inventory

Population exposure to ambient particulate matter (PM) has received considerable attention due to the association between ambient particulate concentrations and mortality. Current toxicological and epidemiological studies and controlled human and animal exposures suggest that a...

Critical Evaluation of the Linkage Between Tick-Based Risk Measures and the Occurrence of Lyme Disease Cases

PubMed Central

Eisen, Lars; Eisen, Rebecca J.

2018-01-01

The nymphal stage of the blacklegged tick, Ixodes scapularis Say, is considered the primary vector to humans in the eastern United States of the Lyme disease spirochete Borrelia burgdorferi sensu stricto. The abundance of infected host-seeking nymphs is commonly used to estimate the fundamental risk of human exposure to B. burgdorferi, for the purpose of environmental risk assessment and as an outcome measure when evaluating environmentally based tick or pathogen control methods. However, as this tick-based risk measure does not consider the likelihoods of either human encounters with infected ticks or tick bites resulting in pathogen transmission, its linkage to the occurrence of Lyme disease cases is worth evaluating. In this Forum article, we describe different tick-based risk measures, discuss their strengths and weaknesses, and review the evidence for their capacity to predict the occurrence of Lyme disease cases. We conclude that: 1) the linkage between abundance of host-seeking B. burgdorferi-infected nymphs and Lyme disease occurrence is strong at community or county scales but weak at the fine spatial scale of residential properties where most human exposures to infected nymphs occur in Northeast, 2) the combined use of risk measures based on infected nymphs collected from the environment and ticks collected from humans is preferable to either one of these risk measures used singly when assessing the efficacy of environmentally based tick or pathogen control methods aiming to reduce the risk of human exposure to B. burgdorferi, 3) there is a need for improved risk assessment methodology for residential properties that accounts for both the abundance of infected nymphs and the likelihood of human–tick contact, and 4) we need to better understand how specific human activities conducted in defined residential microhabitats relate to risk for nymphal exposures and bites. PMID:27330093

In Vivo Human Time-Exposure Study of Orally Dosed Commercial Silver Nanoparticles

PubMed Central

Munger, Mark A.; Radwanski, Przemyslaw; Hadlock, Greg C.; Stoddard, Greg; Shaaban, Akram; Falconer, Jonathan; Grainger, David W.; Deering-Rice, Cassandra E.

2013-01-01

Background Human biodistribution, bioprocessing and possible toxicity of nanoscale silver receives increasing health assessment. Methods We prospectively studied commercial 10- and 32-ppm nanoscale silver particle solutions in a single-blind, controlled, cross-over, intent-to-treat, design. Healthy subjects (n=60) underwent metabolic, blood counts, urinalysis, sputum induction, and chest and abdomen magnetic resonance imaging. Silver serum and urine content was determined. Results No clinically important changes in metabolic, hematologic, or urinalysis measures were identified. No morphological changes were detected in the lungs, heart or abdominal organs. No significant changes were noted in pulmonary reactive oxygen species or pro-inflammatory cytokine generation. Conclusion In vivo oral exposure to these commercial nanoscale silver particle solutions does not prompt clinically important changes in human metabolic, hematologic, urine, physical findings or imaging morphology. Further study of increasing time exposure and dosing of silver nanoparticulate silver, and observation of additional organ systems is warranted to assert human toxicity thresholds. PMID:23811290

Atypical scrapie prions from sheep and lack of disease in transgenic mice overexpressing human prion protein.

PubMed

Wadsworth, Jonathan D F; Joiner, Susan; Linehan, Jacqueline M; Balkema-Buschmann, Anne; Spiropoulos, John; Simmons, Marion M; Griffiths, Peter C; Groschup, Martin H; Hope, James; Brandner, Sebastian; Asante, Emmanuel A; Collinge, John

2013-11-01

Public and animal health controls to limit human exposure to animal prions are focused on bovine spongiform encephalopathy (BSE), but other prion strains in ruminants may also have zoonotic potential. One example is atypical/Nor98 scrapie, which evaded statutory diagnostic methods worldwide until the early 2000s. To investigate whether sheep infected with scrapie prions could be another source of infection, we inoculated transgenic mice that overexpressed human prion protein with brain tissue from sheep with natural field cases of classical and atypical scrapie, sheep with experimental BSE, and cattle with BSE. We found that these mice were susceptible to BSE prions, but disease did not develop after prolonged postinoculation periods when mice were inoculated with classical or atypical scrapie prions. These data are consistent with the conclusion that prion disease is less likely to develop in humans after exposure to naturally occurring prions of sheep than after exposure to epizootic BSE prions of ruminants.

Atypical Scrapie Prions from Sheep and Lack of Disease in Transgenic Mice Overexpressing Human Prion Protein

PubMed Central

Joiner, Susan; Linehan, Jacqueline M.; Balkema-Buschmann, Anne; Spiropoulos, John; Simmons, Marion M.; Griffiths, Peter C.; Groschup, Martin H.; Hope, James; Brandner, Sebastian; Asante, Emmanuel A.; Collinge, John

2013-01-01

Public and animal health controls to limit human exposure to animal prions are focused on bovine spongiform encephalopathy (BSE), but other prion strains in ruminants may also have zoonotic potential. One example is atypical/Nor98 scrapie, which evaded statutory diagnostic methods worldwide until the early 2000s. To investigate whether sheep infected with scrapie prions could be another source of infection, we inoculated transgenic mice that overexpressed human prion protein with brain tissue from sheep with natural field cases of classical and atypical scrapie, sheep with experimental BSE, and cattle with BSE. We found that these mice were susceptible to BSE prions, but disease did not develop after prolonged postinoculation periods when mice were inoculated with classical or atypical scrapie prions. These data are consistent with the conclusion that prion disease is less likely to develop in humans after exposure to naturally occurring prions of sheep than after exposure to epizootic BSE prions of ruminants. PMID:24188521

Alteration of Cell Cycle Mediated by Zinc in Human Bronchial ...

EPA Pesticide Factsheets

Zinc (Zn2+), a ubiquitous ambient air contaminant, presents an oxidant challenge to the human lung and is linked to adverse human health effects. To further elucidate the adaptive and apoptotic cellular responses of human airway cells to Zn2+, we performed pilot studies to examine cell cycle perturbation upon exposure using a normal human bronchial epithelial cell culture (BEAS-2B). BEAS-2B cells were treated with low (0, 1, 2 µM) and apoptotic (3 µM) doses of Zn2+ plus 1 µM pyrithione, a Zn2+-specific ionophore facilitating cellular uptake, for up to 24 h. Fixed cells were then stained with propidium iodine (PI) and cell cycle phase was determined by fluorescent image cytometry. Initial results report the percentage of cells in the S phase after 18 h exposure to 1, 2, and 3 µM Zn2+ were similar (8%, 7%, and 12%, respectively) compared with 7% in controls. Cells exposed to 3 µM Zn2+ increased cell populations in G2/M phase (76% versus 68% in controls). Interestingly, exposure to 1 µM Zn2+ resulted in decreased (59%) cells in G2/M. While preliminary, these pilot studies suggest Zn2+ alters cell cycle in BEAS-2B cells, particularly in the G2/M phase. The G2/M checkpoint maintains DNA integrity by enabling initiation of DNA repair or apoptosis. Our findings suggest that the adaptive and apoptotic responses to Zn2+ exposure may be mediated via perturbation of the cell cycle at the G2/M checkpoint. This work was a collaborative summer student project. The st

Shuttle Flight Operations Contract Generator Maintenance Facility Land Use Control Implementation Plan (LUCIP)

NASA Technical Reports Server (NTRS)

Applegate, Joseph L.

2014-01-01

This Land Use Control Implementation Plan (LUCIP) has been prepared to inform current and potential future users of the Kennedy Space Center (KSC) Shuttle Flight Operations Contract Generator Maintenance Facility (SFOC; SWMU 081; "the Site") of institutional controls that have been implemented at the Site1. Although there are no current unacceptable risks to human health or the environment associated with the SFOC, an institutional land use control (LUC) is necessary to prevent human health exposure to antimony-affected groundwater at the Site. Controls will include periodic inspection, condition certification, and agency notification.

Land Use Control Implementation Plan

NASA Technical Reports Server (NTRS)

Starr, Andrew Scott

2015-01-01

This Land Use Control Implementation Plan (LUCIP) has been prepared to inform current and potential future users of Building M7-505 of institutional controls that have been implemented at the site. Although there are no current unacceptable risks to human health or the environment associated with Building M7-505, institutional land use controls (LUCs) are necessary to prohibit the use of groundwater from the site. LUCs are also necessary to prevent access to soil under electrical equipment in the northwest portion of the site. Controls necessary to prevent human exposure will include periodic inspection, condition certification, and agency notification.

Pfiesteria: review of the science and identification of research gaps. Report for the National Center for Environmental Health, Centers for Disease Control and Prevention.

PubMed Central

Samet, J; Bignami, G S; Feldman, R; Hawkins, W; Neff, J; Smayda, T

2001-01-01

In connection with the CDC National Conference on Pfiesteria, a multidisciplinary panel evaluated Pfiesteria-related research. The panel set out what was known and what was not known about adverse effects of the organism on estuarine ecology, fish, and human health; assessed the methods used in Pfiesteria research; and offered suggestions to address data gaps. The panel's expertise covered dinoflagellate ecology; fish pathology and toxicology; laboratory measurement of toxins, epidemiology, and neurology. The panel evaluated peer-reviewed and non-peer-reviewed literature available through June 2000 in a systematic conceptual framework that moved from the source of exposure, through exposure research and dose, to human health effects. Substantial uncertainties remain throughout the conceptual framework the panel used to guide its evaluation. Firm evidence demonstrates that Pfiesteria is toxic to fish, but the specific toxin has not been isolated or characterized. Laboratory and field evidence indicate that the organism has a complex life cycle. The consequences of human exposure to Pfiesteria toxin and the magnitude of the human health problem remain obscure. The patchwork of approaches used in clinical evaluation and surrogate measures of exposure to the toxin are major limitations of this work. To protect public health, the panel suggests that priority be given research that will provide better insight into the effects of Pfiesteria on human health. Key gaps include the identity and mechanism of action of the toxin(s), the incomplete description of effects of exposure in invertebrates, fish, and humans, and the nature and extent of exposures that place people at risk. PMID:11687383

Assessment of Deployment-Related Exposures on Risk of Incident Mental Health Diagnoses Among Air Force Critical Care Providers: Nested Case-Control Study

DTIC Science & Technology

2014-09-04

lasers, and use of mission-oriented protective posture (MOPP) overgarments were associated with increased likelihood for a PDMH condition. 15...history of a vehicular accident/crash, exposure to sand/dust, exposure to lasers, and use of mission-oriented protective posture (MOPP) overgarments...Institutional Review Board and in accordance with Federal and USAF regulations on the protection of human subjects in biomedical and behavioral research

Environmental concentrations of metformin exposure affect aggressive behavior in the Siamese fighting fish, Betta splendens.

PubMed

MacLaren, Ronald David; Wisniewski, Kathryn; MacLaren, Christina

2018-01-01

Metformin, the medicine most commonly prescribed for treatment of Type II diabetes, is among the most abundant pharmaceuticals being introduced into the environment. Pharmaceuticals are increasingly found in wastewater and surface waters around the world, often due to incomplete metabolism in humans and subsequent excretion in human waste. Risk analyses and exposure studies have raised concerns about potential negative impacts of pharmaceuticals at current environmental levels. Results of the present study indicate that metformin at concentrations in the range of what has been documented in freshwater systems and waste-water effluent (40 μg/L) affects aggressive behavior in adult male Betta splendens. Subjects exhibited less aggression toward a male dummy stimulus after four weeks exposure to metformin-treated water when compared to behavior measured immediately prior to their exposure, and in comparison to a separate cohort of un-exposed control fish. This effect persisted after 20 weeks exposure as well. Subjects exposed to metformin at a concentration twice that currently observed in nature (80 μg/L) exhibited an even more substantial reduction in aggressive behaviors compared to controls and pre-exposure measurements than those observed in the low-dose treatment group. Such changes in behavior have the potential to affect male fitness and possibly impact the health of natural populations of aquatic organisms exposed to the drug.

DNA methylation and copy number variation analyses of human embryonic stem cell-derived neuroprogenitors after low-dose decabromodiphenyl ether and/or bisphenol A exposure.

PubMed

Du, L; Sun, W; Li, X M; Li, X Y; Liu, W; Chen, D

2018-05-01

The polybrominated diphenyl ether flame retardants decabromodiphenyl ether (BDE-209) and bisphenol A (BPA) are environmental contaminants that can cross the placenta and exert toxicity in the developing fetal nervous system. Copy number variants (CNVs) play a role in a number of genetic disorders and may be implicated in BDE-209/BPA teratogenicity. In this study, we found that BDE-209 and/or BPA exposure decreased neural differentiation efficiency of human embryonic stem cells (hESCs), although there was a >90% induction of neuronal progenitor cells (NPCs) from exposed hESCs. However, the mean of CNV numbers in the NPCs with BDE-209 + BPA treatment was significantly higher compared to the other groups, whereas DNA methylation was lower and DNA methyltransferase(DNMT1 and DNMT3A) expression were significantly decreased in all of the BDE-209 and/or BPA treatment groups compared with the control groups. The number of CNVs in chromosomes 3, 4, 11, 22, and X in NPCs with BDE-209 and/or BPA exposure was higher compared to the control group. In addition, CNVs in chromosomes 7, 8, 14, and 16 were stable in hESCs and hESCs-derived NPCs irrespective of BDE-209/BPA exposure, and CNVs in chromosomes 20 q11.21 and 16 p13.11 might be induced by neural differentiation. Thus, BDE-209/BPA exposure emerges as a potential source of CNVs distinct from neural differentiation by itself. BDE-209 and/or BPA exposure may cause genomic instability in cultured stem cells via reduced activity of DNA methyltransferase, suggesting a new mechanism of human embryonic neurodevelopmental toxicity caused by this class of environmental toxins.

Pornography, Human Mutilation and Psychological Dysfunction.

ERIC Educational Resources Information Center

Shaughnessy, Michael F.

Pornography is widely available and inevitably linked to crime and abnormal behavior. Social scientists must be concerned with the long-term effects on consenting adults and children and adolescents of exposure to pornography and human mutilation. An experiment in which a treatment group is exposed to pornography and a control group is exposed…

Subchronic Toluene Exposure alters Retinal Function in Long Evans Rats: Experimental Evidence Supporting Observations from Studies of Exposed Humans.

EPA Science Inventory

Studies of humans chronically exposed to volatile organic solvents commonly report impaired visual functions, including low contrast sensitivity and reduced color discrimination. These reports have been controversial, however, in part due to a lack of confirmation from controlled...

Costs of Rabies Control: An Economic Calculation Method Applied to Flores Island

PubMed Central

Wera, Ewaldus; Velthuis, Annet G. J.; Geong, Maria; Hogeveen, Henk

2013-01-01

Background Rabies is a zoonotic disease that, in most human cases, is fatal once clinical signs appear. The disease transmits to humans through an animal bite. Dogs are the main vector of rabies in humans on Flores Island, Indonesia, resulting in about 19 human deaths each year. Currently, rabies control measures on Flores Island include mass vaccination and culling of dogs, laboratory diagnostics of suspected rabid dogs, putting imported dogs in quarantine, and pre- and post-exposure treatment (PET) of humans. The objective of this study was to estimate the costs of the applied rabies control measures on Flores Island. Methodology/principal findings A deterministic economic model was developed to calculate the costs of the rabies control measures and their individual cost components from 2000 to 2011. The inputs for the economic model were obtained from (i) relevant literature, (ii) available data on Flores Island, and (iii) experts such as responsible policy makers and veterinarians involved in rabies control measures in the past. As a result, the total costs of rabies control measures were estimated to be US$1.12 million (range: US$0.60–1.47 million) per year. The costs of culling roaming dogs were the highest portion, about 39 percent of the total costs, followed by PET (35 percent), mass vaccination (24 percent), pre-exposure treatment (1.4 percent), and others (1.3 percent) (dog-bite investigation, diagnostic of suspected rabid dogs, trace-back investigation of human contact with rabid dogs, and quarantine of imported dogs). Conclusions/significance This study demonstrates that rabies has a large economic impact on the government and dog owners. Control of rabies by culling dogs is relatively costly for the dog owners in comparison with other measures. Providing PET for humans is an effective way to prevent rabies, but is costly for government and does not provide a permanent solution to rabies in the future. PMID:24386244

Identification of Biomarkers of Exposure to FTOHs and PAPs in Humans Using a Targeted and Nontargeted Analysis Approach.

PubMed

Dagnino, Sonia; Strynar, Mark J; McMahen, Rebecca L; Lau, Christopher S; Ball, Carol; Garantziotis, Stavros; Webster, Thomas F; McClean, Michael D; Lindstrom, Andrew B

2016-09-20

Although historic perfluorinated compounds are currently under scrutiny and growing regulatory control in the world, little is known about human exposure to other polyfluorinated compounds presently in use. Fluorotelomer alcohols (FTOHs) and polyfluoroalkyl phosphate esters (PAPs) are known to degrade to terminal perfluorinated acids and toxic reactive intermediates through metabolic pathways. Therefore, it is important to characterize their human exposure by the identification of unique biomarkers. With the use of liquid chromatography-mass spectrometry-time-of-flight analysis (LC-MS-TOF), we developed a workflow for the identification of metabolites for the 8:2 FTOH and 8:2 diPAP. Analysis of serum and urine of dosed rats indicated the 8:2 FTOH-sulfate and the 8:2 diPAP as potential biomarkers. These compounds, as well as 25 other fluorinated compounds and metabolites, were analyzed in human serum and urine samples from the general population (n = 100) and office workers (n = 30). The 8:2 FTOH-sulfate was measured for the first time in human samples in 5 to 10% of the serum samples, ranging from 50 to 80 pg/mL. The 8:2 diPAP was measured in 58% of the samples, ranging from 100 to 800 pg/mL. This study indicates the FTOH-sulfate conjugate as a biomarker of exposure to FTOHs and PAPs in humans.

Heavy Metal Risk Management: Case Analysis

PubMed Central

Kim, Ji Ae; Lee, Seung Ha; Choi, Seung Hyun; Jung, Ki Kyung; Park, Mi Sun; Jeong, Ji Yoon; Hwang, Myung Sil; Yoon, Hae Jung; Choi, Dal Woong

2012-01-01

To prepare measures for practical policy utilization and the control of heavy metals, hazard control related institutions by country, present states of control by country, and present states of control by heavy metals were examined. Hazard control cases by heavy metals in various countries were compared and analyzed. In certain countries (e.g., the U.S., the U.K., and Japan), hazardous substances found in foods (e.g., arsenic, lead, cadmium, and mercury) are controlled. In addition, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) recommends calculating the provisional tolerable weekly intake (PTWI) of individual heavy metals instead of the acceptable daily intake (ADI) to compare their pollution levels considering their toxicity accumulated in the human body. In Korea, exposure assessments have been conducted, and in other countries, hazardous substances are controlled by various governing bodies. As such, in Korea and other countries, diverse food heavy metal monitoring and human body exposure assessments are conducted, and reducing measures are prepared accordingly. To reduce the danger of hazardous substances, many countries provide leaflets and guidelines, develop hazardous heavy metal intake recommendations, and take necessary actions. Hazard control case analyses can assist in securing consumer safety by establishing systematic and reliable hazard control methods. PMID:24278603

Health consequences of exposure to brominated flame retardants: a systematic review.

PubMed

Kim, Young Ran; Harden, Fiona A; Toms, Leisa-Maree L; Norman, Rosana E

2014-07-01

Brominated flame retardants (BFRs), are chemicals widely used in consumer products including electronics, vehicles, plastics and textiles to reduce flammability. Experimental animal studies have confirmed that these compounds may interfere with thyroid hormone homeostasis and neurodevelopment but to date health effects in humans have not been systematically examined. To conduct a systematic review of studies on the health impacts of exposure to BFRs in humans, with a particular focus on children. A systematic review was conducted using the MEDLINE and EMBASE electronic databases up to 1 February 2012. Published cohort, cross-sectional, and case-control studies exploring the relationship between BFR exposure and various health outcomes were included. In total, 36 epidemiological studies meeting the pre-determined inclusion criteria were included. Plausible outcomes associated with BFR exposure include diabetes, neurobehavioral and developmental disorders, cancer, reproductive health effects and alteration in thyroid function. Evidence for a causal relationship between exposure to BFRs and health outcomes was evaluated within the Bradford Hill framework. Although there is suggestive evidence that exposure to BFRs is harmful to health, further epidemiological investigations particularly among children, and long-term monitoring and surveillance of chemical impacts on humans are required to confirm these relationships. Copyright © 2014 Elsevier Ltd. All rights reserved.

Chronic Ketamine Exposure Causes White Matter Microstructural Abnormalities in Adolescent Cynomolgus Monkeys.

PubMed

Li, Qi; Shi, Lin; Lu, Gang; Yu, Hong-Luan; Yeung, Fu-Ki; Wong, Nai-Kei; Sun, Lin; Liu, Kai; Yew, David; Pan, Fang; Wang, De-Feng; Sham, Pak C

2017-01-01

Acute and repeated exposures to ketamine mimic aspects of positive, negative, and cognitive symptoms of schizophrenia in humans. Recent studies by our group and others have shown that chronicity of ketamine use may be a key element for establishing a more valid model of cognitive symptoms of schizophrenia. However, current understanding on the long-term consequences of ketamine exposure on brain circuits has remained incomplete, particularly with regard to microstructural changes of white matter tracts that underpin the neuropathology of schizophrenia. Thus, the present study aimed to expand on previous investigations by examining causal effects of repeated ketamine exposure on white matter integrity in a non-human primate model. Ketamine or saline (control) was administered intravenously for 3 months to male adolescent cynomolgus monkeys ( n = 5/group). Diffusion tensor imaging (DTI) experiments were performed and tract-based spatial statistics (TBSS) was used for data analysis. Fractional anisotropy (FA) was quantified across the whole brain. Profoundly reduced FA on the right side of sagittal striatum, posterior thalamic radiation (PTR), retrolenticular limb of the internal capsule (RLIC) and superior longitudinal fasciculus (SLF), and on the left side of PTR, middle temporal gyrus and inferior frontal gyrus were observed in the ketamine group compared to controls. Diminished white matter integrity found in either fronto-thalamo-temporal or striato-thalamic connections with tracts including the SLF, PTR, and RLIC lends support to similar findings from DTI studies on schizophrenia in humans. This study suggests that chronic ketamine exposure is a useful pharmacological paradigm that might provide translational insights into the pathophysiology and treatment of schizophrenia.

Genome-wide alteration in DNA hydroxymethylation in the sperm from bisphenol A-exposed men

PubMed Central

Li, De-kun; Yang, Fen; Pan, Hongjie; Li, Tianqi; Miao, Maohua; Li, Runsheng; Yuan, Wei

2017-01-01

Environmental BPA exposure has been shown to impact human sperm concentration and motility, as well as rodent spermatogenesis. However, it is unclear whether BPA exposure is associated with alteration in DNA hydroxymethylation, a marker for epigenetic modification, in human sperm. A genome-wide DNA hydroxymethylation study was performed using sperm samples of men who were occupationally exposed to BPA. Compared with controls who had no occupational BPA exposure, the total levels of 5-hydroxymethylcytosine (5hmc) increased significantly (19.37% increase) in BPA-exposed men, with 72.69% of genome regions harboring 5hmc. A total of 9,610 differential 5hmc regions (DhMRs) were revealed in BPA-exposed men relative to controls, which were mainly located in intergenic and intron regions. These DhMRs were composed of 8,670 hyper-hMRs and 940 hypo-hMRs, affecting 2,008 genes and the repetitive elements. The hyper-hMRs affected genes were enriched in pathways associated with nervous system, development, cardiovascular diseases and signal transduction. Additionally, enrichment of 5hmc was observed in the promoters of eight maternally expressed imprinted genes in BPA-exposed sperm. Some of the BPA-affected genes, for example, MLH1, CHD2, SPATA12 and SPATA20 might participate in the response to DNA damage in germ cells caused by BPA. Our analysis showed that enrichment of 5hmc both in promoters and gene bodies is higher in the genes whose expression has been detected in human sperm than those whose expression is absent. Importantly, we observed that BPA exposure affected the 5hmc level in 11.4% of these genes expressed in sperm, and in 6.85% of the sperm genome. Finally, we also observed that BPA exposure tends to change the 5hmc enrichment in the genes which was previously reported to be distributed with the trimethylated Histone 3 (H3K27me3, H3K4me2 or H3K4me3) in sperm. Thus, these results suggest that BPA exposure likely interferes with gene expression via affecting DNA hydroxymethylation in a way partially dependent on trimethylation of H3 in human spermatogenesis. Our current study reveals a new mechanism by which BPA exposure reduces human sperm quality. PMID:28582417

Genome-wide alteration in DNA hydroxymethylation in the sperm from bisphenol A-exposed men.

PubMed

Zheng, Huajun; Zhou, Xiaoyu; Li, De-Kun; Yang, Fen; Pan, Hongjie; Li, Tianqi; Miao, Maohua; Li, Runsheng; Yuan, Wei

2017-01-01

Environmental BPA exposure has been shown to impact human sperm concentration and motility, as well as rodent spermatogenesis. However, it is unclear whether BPA exposure is associated with alteration in DNA hydroxymethylation, a marker for epigenetic modification, in human sperm. A genome-wide DNA hydroxymethylation study was performed using sperm samples of men who were occupationally exposed to BPA. Compared with controls who had no occupational BPA exposure, the total levels of 5-hydroxymethylcytosine (5hmc) increased significantly (19.37% increase) in BPA-exposed men, with 72.69% of genome regions harboring 5hmc. A total of 9,610 differential 5hmc regions (DhMRs) were revealed in BPA-exposed men relative to controls, which were mainly located in intergenic and intron regions. These DhMRs were composed of 8,670 hyper-hMRs and 940 hypo-hMRs, affecting 2,008 genes and the repetitive elements. The hyper-hMRs affected genes were enriched in pathways associated with nervous system, development, cardiovascular diseases and signal transduction. Additionally, enrichment of 5hmc was observed in the promoters of eight maternally expressed imprinted genes in BPA-exposed sperm. Some of the BPA-affected genes, for example, MLH1, CHD2, SPATA12 and SPATA20 might participate in the response to DNA damage in germ cells caused by BPA. Our analysis showed that enrichment of 5hmc both in promoters and gene bodies is higher in the genes whose expression has been detected in human sperm than those whose expression is absent. Importantly, we observed that BPA exposure affected the 5hmc level in 11.4% of these genes expressed in sperm, and in 6.85% of the sperm genome. Finally, we also observed that BPA exposure tends to change the 5hmc enrichment in the genes which was previously reported to be distributed with the trimethylated Histone 3 (H3K27me3, H3K4me2 or H3K4me3) in sperm. Thus, these results suggest that BPA exposure likely interferes with gene expression via affecting DNA hydroxymethylation in a way partially dependent on trimethylation of H3 in human spermatogenesis. Our current study reveals a new mechanism by which BPA exposure reduces human sperm quality.

Quantitative comparisons of the acute neurotoxicity of toluene in rats and humans.

PubMed

Benignus, Vernon A; Boyes, William K; Kenyon, Elaina M; Bushnell, Philip J

2007-11-01

The behavioral and neurophysiological effects of acute exposure to toluene are the most thoroughly explored of all the hydrocarbon solvents. Behavioral effects have been experimentally studied in humans and other species, for example, rats. The existence of both rat and human dosimetric data offers the opportunity to quantitatively compare the relative sensitivity to acute toluene exposure. The purpose of this study was to fit dose-effect curves to existing data and to estimate the dose-equivalence equation (DEE) between rats and humans. The DEE gives the doses that produce the same magnitude of effect in the two species. Doses were brain concentrations of toluene estimated from physiologically based pharmacokinetic models. Human experiments measuring toluene effects on choice reaction time (CRT) were meta-analyzed. Rat studies employed various dependent variables: amplitude of visual-evoked potentials (VEPs), signal detection (SIGDET) accuracy (ACCU) and reaction time (RT), and escape-avoidance (ES-AV) behaviors. Comparison of dose-effect functions showed that human and rat sensitivity was practically the same for those two task regimens that exerted the least control over the behaviors being measured (VEP in rats and CRT in humans) and the sensitivity was progressively lower for SIGDET RT, SIGDET ACCU, and ES-AV behaviors in rats. These results suggested that the sensitivity to impairment by toluene depends on the strength of control over the measured behavior rather than on the species being tested. This interpretation suggests that (1) sensitivity to toluene would be equivalent in humans and rats if both species performed behaviors that were controlled to the same extent, (2) the most sensitive tests of neurobehavioral effects would be those in which least control is exerted on the behavior being measured, and (3) effects of toluene in humans may be estimated using the DEEs from rat studies despite differences in the amount of control exerted by the experimental regimen or differences in the behaviors under investigation.

Hydrocarbon exposure may cause glomerulonephritis and worsen renal function: evidence based on Hill's criteria for causality.

PubMed

Ravnskov, U

2000-08-01

Many observational and experimental studies point to hydrocarbon exposure as an important pathogenic factor in glomerulonephritis. The findings have made little impact on current concepts and patient care, possibly because the hypothesis of a direct causal effect of the exposure and the hypothesis that the exposure worsens renal function have not been considered separately. This review examines these two hypotheses using Hill's criteria for causality. The results from 14 cross-sectional, 18 case-control studies, two cohort studies, 15 experiments on laboratory animals and two on human beings together with many case reports satisfy all but one of Hill's criteria for both hypotheses. Of particular importance is the finding in the case-control and follow-up studies of an association between degree of exposure and stage of renal disease, and an inverse association between degree of exposure and renal function, indicating that the most important effect of hydrocarbon exposure is its effect on renal function. End-stage renal failure may be preventable in many patients with glomerulonephritis provided a possible exposure to toxic chemicals is discontinued.

Potential mechanisms for cancer resistance in elephants and comparative cellular response to DNA damage in humans

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

Abegglen, Lisa M.; Caulin, Aleah F.; Chan, Ashley

Here, evolutionary medicine may provide insights into human physiology and pathophysiology, including tumor biology. To identify mechanisms for cancer resistance in elephants and compare cellular response to DNA damage among elephants, healthy human controls, and cancer-prone patients with Li-Fraumeni syndrome (LFS). Design, Setting, and Participants A comprehensive survey of necropsy data was performed across 36 mammalian species to validate cancer resistance in large and long-lived organisms, including elephants (n=644). The African and Asian elephant genomes were analyzed for potential mechanisms of cancer resistance. Peripheral blood lymphocytes from elephants, healthy human controls, and patients with LFS were tested in vitro inmore » the laboratory for DNA damage response. The study included African and Asian elephants (n=8), patients with LFS (n=10), and age-matched human controls (n=11). Human samples were collected at the University of Utah between June 2014 and July 2015. Exposures Ionizing radiation and doxorubicin. Cancer mortality across species was calculated and compared by body size and life span. The elephant genome was investigated for alterations in cancer-related genes. DNA repair and apoptosis were compared in elephant vs human peripheral blood lymphocytes. Across mammals, cancer mortality did not increase with body size and/or maximum life span (eg, for rock hyrax, 1% [95% CI, 0%-5%]; African wild dog, 8% [95% CI, 0%-16%]; lion, 2% [95% CI, 0%-7%]). Despite their large body size and long life span, elephants remain cancer resistant, with an estimated cancer mortality of 4.81% (95% CI, 3.14%-6.49%), compared with humans, who have 11% to 25% cancer mortality. While humans have 1 copy (2 alleles) of TP53, African elephants have at least 20 copies (40 alleles), including 19 retrogenes (38 alleles) with evidence of transcriptional activity measured by reverse transcription polymerase chain reaction. In response to DNA damage, elephant lymphocytes underwent p53-mediated apoptosis at higher rates than human lymphocytes proportional to TP53 status (ionizing radiation exposure: patients with LFS, 2.71% [95% CI, 1.93%-3.48%] vs human controls, 7.17% [95% CI, 5.91%-8.44%] vs elephants, 14.64% [95% CI, 10.91%-18.37%]; P<.001; doxorubicin exposure: human controls, 8.10% [95% CI, 6.55%-9.66%] vs elephants, 24.77% [95% CI, 23.0%-26.53%]; P<.001). Compared with other mammalian species, elephants appeared to have a lower-than-expected rate of cancer, potentially related to multiple copies of TP53. Compared with human cells, elephant cells demonstrated increased apoptotic response following DNA damage. These findings, if replicated, could represent an evolutionary-based approach for understanding mechanisms related to cancer suppression.« less

Potential mechanisms for cancer resistance in elephants and comparative cellular response to DNA damage in humans

DOE PAGES

Abegglen, Lisa M.; Caulin, Aleah F.; Chan, Ashley; ...

2015-10-08

Here, evolutionary medicine may provide insights into human physiology and pathophysiology, including tumor biology. To identify mechanisms for cancer resistance in elephants and compare cellular response to DNA damage among elephants, healthy human controls, and cancer-prone patients with Li-Fraumeni syndrome (LFS). Design, Setting, and Participants A comprehensive survey of necropsy data was performed across 36 mammalian species to validate cancer resistance in large and long-lived organisms, including elephants (n=644). The African and Asian elephant genomes were analyzed for potential mechanisms of cancer resistance. Peripheral blood lymphocytes from elephants, healthy human controls, and patients with LFS were tested in vitro inmore » the laboratory for DNA damage response. The study included African and Asian elephants (n=8), patients with LFS (n=10), and age-matched human controls (n=11). Human samples were collected at the University of Utah between June 2014 and July 2015. Exposures Ionizing radiation and doxorubicin. Cancer mortality across species was calculated and compared by body size and life span. The elephant genome was investigated for alterations in cancer-related genes. DNA repair and apoptosis were compared in elephant vs human peripheral blood lymphocytes. Across mammals, cancer mortality did not increase with body size and/or maximum life span (eg, for rock hyrax, 1% [95% CI, 0%-5%]; African wild dog, 8% [95% CI, 0%-16%]; lion, 2% [95% CI, 0%-7%]). Despite their large body size and long life span, elephants remain cancer resistant, with an estimated cancer mortality of 4.81% (95% CI, 3.14%-6.49%), compared with humans, who have 11% to 25% cancer mortality. While humans have 1 copy (2 alleles) of TP53, African elephants have at least 20 copies (40 alleles), including 19 retrogenes (38 alleles) with evidence of transcriptional activity measured by reverse transcription polymerase chain reaction. In response to DNA damage, elephant lymphocytes underwent p53-mediated apoptosis at higher rates than human lymphocytes proportional to TP53 status (ionizing radiation exposure: patients with LFS, 2.71% [95% CI, 1.93%-3.48%] vs human controls, 7.17% [95% CI, 5.91%-8.44%] vs elephants, 14.64% [95% CI, 10.91%-18.37%]; P<.001; doxorubicin exposure: human controls, 8.10% [95% CI, 6.55%-9.66%] vs elephants, 24.77% [95% CI, 23.0%-26.53%]; P<.001). Compared with other mammalian species, elephants appeared to have a lower-than-expected rate of cancer, potentially related to multiple copies of TP53. Compared with human cells, elephant cells demonstrated increased apoptotic response following DNA damage. These findings, if replicated, could represent an evolutionary-based approach for understanding mechanisms related to cancer suppression.« less

Weight-of-evidence evaluation of short-term ozone exposure and cardiovascular effects.

PubMed

Goodman, Julie E; Prueitt, Robyn L; Sax, Sonja N; Lynch, Heather N; Zu, Ke; Lemay, Julie C; King, Joseph M; Venditti, Ferdinand J

2014-10-01

There is a relatively large body of research on the potential cardiovascular (CV) effects associated with short-term ozone exposure (defined by EPA as less than 30 days in duration). We conducted a weight-of-evidence (WoE) analysis to assess whether it supports a causal relationship using a novel WoE framework adapted from the US EPA's National Ambient Air Quality Standards causality framework. Specifically, we synthesized and critically evaluated the relevant epidemiology, controlled human exposure, and experimental animal data and made a causal determination using the same categories proposed by the Institute of Medicine report Improving the Presumptive Disability Decision-making Process for Veterans ( IOM 2008). We found that the totality of the data indicates that the results for CV effects are largely null across human and experimental animal studies. The few statistically significant associations reported in epidemiology studies of CV morbidity and mortality are very small in magnitude and likely attributable to confounding, bias, or chance. In experimental animal studies, the reported statistically significant effects at high exposures are not observed at lower exposures and thus not likely relevant to current ambient ozone exposures in humans. The available data also do not support a biologically plausible mechanism for CV effects of ozone. Overall, the current WoE provides no convincing case for a causal relationship between short-term exposure to ambient ozone and adverse effects on the CV system in humans, but the limitations of the available studies preclude definitive conclusions regarding a lack of causation. Thus, we categorize the strength of evidence for a causal relationship between short-term exposure to ozone and CV effects as "below equipoise."

Integrative Radiation Biology

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

Barcellos-Hoff, Mary Helen

We plan to study tissue-level mechanisms important to human breast radiation carcinogenesis. We propose that the cell biology of irradiated tissues reveals a coordinated multicellular damage response program in which individual cell contributions are primarily directed towards suppression of carcinogenesis and reestablishment of homeostasis. We identified transforming growth factor β1 (TGFβ) as a pivotal signal. Notably, we have discovered that TGFβ suppresses genomic instability by controlling the intrinsic DNA damage response and centrosome integrity. However, TGFβ also mediates disruption of microenvironment interactions, which drive epithelial to mesenchymal transition in irradiated human mammary epithelial cells. This apparent paradox of positive andmore » negative controls by TGFβ is the topic of the present proposal. First, we postulate that these phenotypes manifest differentially following fractionated or chronic exposures; second, that the interactions of multiple cell types in tissues modify the responses evident in this single cell type culture models. The goals are to: 1) study the effect of low dose rate and fractionated radiation exposure in combination with TGFβ on the irradiated phenotype and genomic instability of non-malignant human epithelial cells; and 2) determine whether stromal-epithelial interactions suppress the irradiated phenotype in cell culture and the humanized mammary mouse model. These data will be used to 3) develop a systems biology model that integrates radiation effects across multiple levels of tissue organization and time. Modeling multicellular radiation responses coordinated via extracellular signaling could have a significant impact on the extrapolation of human health risks from high dose to low dose/rate radiation exposure.« less

Safety issues associated with the use of nanoparticles in human body.

PubMed

Sufian, Mian Muhammad; Khattak, Jabar Zaman Khan; Yousaf, Shahzad; Rana, Muhammad Suleman

2017-09-01

Nanotechnology has transformed the world by the introduction of a distinctive class of materials and products in a wide array of fields. It has contributed to the production of innovative materials and devices. Having unique advantages and domestic along with industrial applications, however, has raised the issue of safety for consumers, producers and environment. Having a comparative smaller dimension and other exclusive properties, nanoparticles have the ability to harm human body by interacting through various mechanisms. Here, we endeavoured to review and discuss the characteristics of nanoparticles relevant to their toxicity, conceivable exposure routes of nanoparticles to human body like skin contact, inhalation, and ingestion, and the basic approaches which can aid to control human exposures to toxic nanoparticles have been discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Characteristics of chromosome instability in the human lymphoblast cell line WTK1

NASA Technical Reports Server (NTRS)

Schwartz, J. L.; Jordan, R.; Evans, H. H.

2001-01-01

The characteristics of spontaneous and radiation-induced chromosome instability were determined in each of 50 individual clones isolated from control populations of human lymphoblasts (WTK1), as well as from populations of these cells previously exposed to two different types of ionizing radiation, Fe-56 and Cs-137. The types of chromosome instability did not appear to change in clones surviving radiation exposure. Aneuploidy, polyploidy, chromosome dicentrics and translocations, and chromatid breaks and gaps were found in both control and irradiated clones. The primary effect of radiation exposure was to increase the number of cells within any one clone that had chromosome alterations. Chromosome instability was associated with telomere shortening and elevated levels of apoptosis. The results suggest that the proximal cause of chromosome instability is telomere shortening.

Application of cytogenetic endpoints and comet assay on human lymphocytes treated with atorvastatin in vitro.

PubMed

Gajski, Goran; Garaj-Vrhovac, Vera

2008-01-01

This study investigated the genotoxic potential of atorvastatin on human lymphocytes using comet assay, structural chromosome aberrations (CA) and sister-chromatid exchange (SCE) analysis. Lymphocyte cultures were treated with a single drug at a concentration of 30.21 ng/mL. For comet assay, cells exposed to atorvastatin for 24 h, 48 h and 72 h were embedded in agarose slides, lysed with alkaline lysis solution and exposed to an electric field. DNA migrated within the agarose and formed comets whose length depends on the amount of DNA damage. For analysis of structural CA, cells were grown on medium for 48 h and for SCE analysis for 72 h. Structural CA did not induce significant damage to the genome, although a higher CA frequency was observed in cells treated with atorvastatin for 3 h, 20 h and 48 h than in control samples. Results of the SCE analysis did show statistically significant differences in the mean SCE number between atorvastatin-exposed and control human lymphocytes and between different exposure times. Comet assay also showed increased DNA damage caused in atorvastatin-exposed human lymphocytes than in corresponding control cells for exposure times of 24 h, 48 h and 72 h for the tail length and for 72 h for the tail moment. Results obtained in this study point to the significance of biological indicators providing information on the primary genome damage after long-term exposure, which can help to establish drug therapeutic concentrations that do not put patients with high blood cholesterol to a greater treatment-related risk.

A Controlled Trial to Reduce the Risk of Human Nipah Virus Exposure in Bangladesh.

PubMed

Nahar, Nazmun; Paul, Repon C; Sultana, Rebeca; Sumon, Shariful Amin; Banik, Kajal Chandra; Abedin, Jaynal; Asaduzzaman, Mohammad; Garcia, Fernando; Zimicki, Susan; Rahman, Mahmudur; Gurley, Emily S; Luby, Stephen P

2017-09-01

Human Nipah virus (NiV) infection, often fatal in Bangladesh, is primarily transmitted by drinking raw date palm sap contaminated by Pteropus bats. We assessed the impact of a behavior change communication intervention on reducing consumption of potentially NiV-contaminated raw sap. During the 2012-2014 sap harvesting seasons, we implemented interventions in two areas and compared results with a control area. In one area, we disseminated a "do not drink raw sap" message and, in the other area, encouraged only drinking sap if it had been protected from bat contamination by a barrier ("only safe sap"). Post-intervention, 40% more respondents in both intervention areas reported knowing about a disease contracted through raw sap consumption compared with control. Reported raw sap consumption decreased in all areas. The reductions in the intervention areas were not significantly greater compared to the control. Respondents directly exposed to the "only safe sap" message were more likely to report consuming raw sap from a protected source than those with no exposure (25 vs. 15%, OR 2.0, 95% CI 1.5-2.6, P < 0.001). While the intervention increased knowledge in both intervention areas, the "only safe sap" intervention reduced exposure to potentially NiV-contaminated sap and should be considered for future dissemination.

Upregulation of SQSTM1/p62 contributes to nickel-induced malignant transformation of human bronchial epithelial cells.

PubMed

Huang, Haishan; Zhu, Junlan; Li, Yang; Zhang, Liping; Gu, Jiayan; Xie, Qipeng; Jin, Honglei; Che, Xun; Li, Jingxia; Huang, Chao; Chen, Lung-Chi; Lyu, Jianxin; Gao, Jimin; Huang, Chuanshu

2016-10-02

Chronic lung inflammation is accepted as being associated with the development of lung cancer caused by nickel exposure. Therefore, identifying the molecular mechanisms that lead to a nickel-induced sustained inflammatory microenvironment that causes transformation of human bronchial epithelial cells is of high significance. In the current studies, we identified SQSTM1/p62 as a novel nickel-upregulated protein that is important for nickel-induced inflammatory TNF expression, subsequently resulting in transformation of human bronchial epithelial cells. We found that nickel exposure induced SQSTM1 protein upregulation in human lung epithelial cells in vitro and in mouse lung tissues in vivo. The SQSTM1 upregulation was also observed in human lung squamous cell carcinoma. Further studies revealed that the knockdown of SQSTM1 expression dramatically inhibited transformation of human lung epithelial cells upon chronic nickel exposure, whereas ectopic expression of SQSTM1 promoted such transformation. Mechanistic studies showed that the SQSTM1 upregulation by nickel was the compromised result of upregulating SQSTM1 mRNA transcription and promoting SQSTM1 protein degradation. We demonstrated that nickel-initiated SQSTM1 protein degradation is mediated by macroautophagy/autophagy via an MTOR-ULK1-BECN1 axis, whereas RELA is important for SQSTM1 transcriptional upregulation following nickel exposure. Furthermore, SQSTM1 upregulation exhibited its promotion of nickel-induced cell transformation through exerting an impetus for nickel-induced inflammatory TNF mRNA stability. Consistently, the MTOR-ULK1-BECN1 autophagic cascade acted as an inhibitory effect on nickel-induced TNF expression and cell transformation. Collectively, our results demonstrate a novel SQSTM1 regulatory network that promotes a nickel-induced tumorigenic effect in human bronchial epithelial cells, which is negatively controlled by an autophagic cascade following nickel exposure.

Upregulation of SQSTM1/p62 contributes to nickel-induced malignant transformation of human bronchial epithelial cells

PubMed Central

Huang, Haishan; Zhu, Junlan; Li, Yang; Zhang, Liping; Gu, Jiayan; Xie, Qipeng; Jin, Honglei; Che, Xun; Li, Jingxia; Huang, Chao; Chen, Lung-Chi; Lyu, Jianxin; Gao, Jimin; Huang, Chuanshu

2016-01-01

ABSTRACT Chronic lung inflammation is accepted as being associated with the development of lung cancer caused by nickel exposure. Therefore, identifying the molecular mechanisms that lead to a nickel-induced sustained inflammatory microenvironment that causes transformation of human bronchial epithelial cells is of high significance. In the current studies, we identified SQSTM1/p62 as a novel nickel-upregulated protein that is important for nickel-induced inflammatory TNF expression, subsequently resulting in transformation of human bronchial epithelial cells. We found that nickel exposure induced SQSTM1 protein upregulation in human lung epithelial cells in vitro and in mouse lung tissues in vivo. The SQSTM1 upregulation was also observed in human lung squamous cell carcinoma. Further studies revealed that the knockdown of SQSTM1 expression dramatically inhibited transformation of human lung epithelial cells upon chronic nickel exposure, whereas ectopic expression of SQSTM1 promoted such transformation. Mechanistic studies showed that the SQSTM1 upregulation by nickel was the compromised result of upregulating SQSTM1 mRNA transcription and promoting SQSTM1 protein degradation. We demonstrated that nickel-initiated SQSTM1 protein degradation is mediated by macroautophagy/autophagy via an MTOR-ULK1-BECN1 axis, whereas RELA is important for SQSTM1 transcriptional upregulation following nickel exposure. Furthermore, SQSTM1 upregulation exhibited its promotion of nickel-induced cell transformation through exerting an impetus for nickel-induced inflammatory TNF mRNA stability. Consistently, the MTOR-ULK1-BECN1 autophagic cascade acted as an inhibitory effect on nickel-induced TNF expression and cell transformation. Collectively, our results demonstrate a novel SQSTM1 regulatory network that promotes a nickel-induced tumorigenic effect in human bronchial epithelial cells, which is negatively controlled by an autophagic cascade following nickel exposure. PMID:27467530

Environmentally relevant mixing ratios in cumulative assessments: a study on the correlation of blood and brain concentrations of a mixture of pyrethroid insecticides to neurotoxicity in the rat

EPA Science Inventory

Human exposure to multiple pyrethroid insecticides may occur because of their broad use on crops and for residential pest control. To address the potential health risk from co-exposure to pyrethroids, it is important to understand their disposition and toxicity in target organs ...

Genotoxic effects of occupational exposure to benzene in gasoline station workers

PubMed Central

SALEM, Eman; EL-GARAWANI, Islam; ALLAM, Heba; EL-AAL, Bahiga Abd; HEGAZY, Mofrih

2017-01-01

Benzene, a hazardous component of gasoline, is a genotoxic class I human carcinogen. This study evaluated the genotoxic effects of occupational exposure to benzene in gasoline stations. Genotoxicity of exposure to benzene was assessed in peripheral blood leucocytes of 62 gasoline station workers and compared with an equal numbers of matched controls using total genomic DNA fragmentation, micronucleus test and cell viability test. An ambient air samples were collected and analyzed for Monitoring of benzene, toluene, ethyl benzene and xylene (BTEX) in work environment and control areas. DNA fragmentation, micronucleus and dead cells percent were significantly higher in exposed workers than controls. Level of benzene, Toluene, Ethyl benzene and xylene in the work environment were higher than the control areas and the permissible limits. Gasoline station workers occupationally exposed to benzene are susceptible to genotoxic effects indicated by increased DNA fragmentation, higher frequency of micronucleus and decreased leukocytes viability. PMID:29070767

Genotoxic effects of occupational exposure to benzene in gasoline station workers.

PubMed

Salem, Eman; El-Garawani, Islam; Allam, Heba; El-Aal, Bahiga Abd; Hegazy, Mofrih

2018-04-07

Benzene, a hazardous component of gasoline, is a genotoxic class I human carcinogen. This study evaluated the genotoxic effects of occupational exposure to benzene in gasoline stations. Genotoxicity of exposure to benzene was assessed in peripheral blood leucocytes of 62 gasoline station workers and compared with an equal numbers of matched controls using total genomic DNA fragmentation, micronucleus test and cell viability test. An ambient air samples were collected and analyzed for Monitoring of benzene, toluene, ethyl benzene and xylene (BTEX) in work environment and control areas. DNA fragmentation, micronucleus and dead cells percent were significantly higher in exposed workers than controls. Level of benzene, Toluene, Ethyl benzene and xylene in the work environment were higher than the control areas and the permissible limits. Gasoline station workers occupationally exposed to benzene are susceptible to genotoxic effects indicated by increased DNA fragmentation, higher frequency of micronucleus and decreased leukocytes viability.

Arsenic exposure and intestinal microbiota in children from Sirajdikhan, Bangladesh.

PubMed

Dong, Xiaoxi; Shulzhenko, Natalia; Lemaitre, Julien; Greer, Renee L; Peremyslova, Kate; Quamruzzaman, Quazi; Rahman, Mahmudar; Hasan, Omar Sharif Ibn; Joya, Sakila Afroz; Golam, Mostofa; Christiani, David C; Morgun, Andriy; Kile, Molly L

2017-01-01

Arsenic has antimicrobial properties at high doses yet few studies have examined its effect on gut microbiota. This warrants investigation since arsenic exposure increases the risk of many diseases in which gut microbiota have been shown to play a role. We examined the association between arsenic exposure from drinking water and the composition of intestinal microbiota in children exposed to low and high arsenic levels during prenatal development and early life. 16S rRNA gene sequencing revealed that children with high arsenic exposure had a higher abundance of Proteobacteria in their stool compared to matched controls with low arsenic exposure. Furthermore, whole metagenome shotgun sequencing identified 332 bacterial SEED functions that were enriched in the high exposure group. A separate model showed that these genes, which included genes involved in virulence and multidrug resistance, were positively correlated with arsenic concentration within the group of children in the high arsenic group. We performed reference free genome assembly, and identified strains of E.coli as contributors to the arsenic enriched SEED functions. Further genome annotation of the E.coli genome revealed two strains containing two different arsenic resistance operons that are not present in the gut microbiome of a recently described European human cohort (Metagenomics of the Human Intestinal Tract, MetaHIT). We then performed quantification by qPCR of two arsenic resistant genes (ArsB, ArsC). We observed that the expression of these two operons was higher among the children with high arsenic exposure compared to matched controls. This preliminary study indicates that arsenic exposure early in life was associated with altered gut microbiota in Bangladeshi children. The enrichment of E.coli arsenic resistance genes in the high exposure group provides an insight into the possible mechanisms of how this toxic compound could affect gut microbiota.

The influence of endocrine disruptors on growth and development of children.

PubMed

DiVall, Sara A

2013-02-01

This review describes the most recent data about the effects of endocrine disrupting compounds (EDCs) on infant and early childhood growth and reproductive tract development as well as controversies in the field. EDCs are present in pregnant women, young children and adolescents. Whether the level of exposure contributes to disease is an ongoing debate. Epidemiological studies suggest associations between prenatal EDC exposure and disease outcome, but animal studies using controlled EDC exposure have varying results with underlying mechanisms largely unknown. Human exposure to EDCs is widespread; bisphenol A, phthalates and persistent organic pollutants are detectable in all age groups and geographical locations in the USA. Epidemiological and animal studies suggest that phthalates and bisphenol A have adverse effects on birth weight, promote development of childhood obesity and adversely affect male reproductive tract development. Differences in the interpretation of available studies underlie the disparate conclusions of scientific and regulatory body's panels on potential toxicological effects of EDCs at current levels of human exposure.

Chlorine isotopic composition of perchlorate in human urine as a means of distinguishing among exposure sources.

PubMed

Poghosyan, Armen; Morel-Espinosa, Maria; Valentin-Blasini, Liza; Blount, Benjamin C; Ferreccio, Catterina; Steinmaus, Craig M; Sturchio, Neil C

2016-01-01

Perchlorate (ClO4(-)) is a ubiquitous environmental contaminant with high human exposure potential. Natural perchlorate forms in the atmosphere from where it deposits onto the surface of Earth, whereas synthetic perchlorate is manufactured as an oxidant for industrial, aerospace, and military applications. Perchlorate exposure can potentially cause adverse health effects in humans by interfering with the production of thyroid hormones through competitively blocking iodide uptake. To control and reduce perchlorate exposure, the contributions of different sources of perchlorate exposure need to be quantified. Thus, we demonstrate a novel approach for determining the contribution of different perchlorate exposure sources by quantifying stable and radioactive chlorine isotopes of perchlorate extracted from composite urine samples from two distinct populations: one in Atlanta, USA and one in Taltal, Chile (Atacama region). Urinary perchlorate from the Atlanta region resembles indigenous natural perchlorate from the western USA (δ(37)Cl=+4.1±1.0‰; (36)Cl/Cl=1 811 (±136) × 10(-15)), and urinary perchlorate from the Taltal, Chile region is similar to natural perchlorate in nitrate salt deposits from the Atacama Desert of northern Chile (δ(37)Cl=-11.0±1.0‰; (36)Cl/Cl=254 (±40) × 10(-15)). Neither urinary perchlorate resembled the isotopic pattern found in synthetic perchlorate. These results indicate that natural perchlorate of regional provenance is the dominant exposure source for the two sample populations, and that chlorine isotope ratios provide a robust tool for elucidating perchlorate exposure pathways.

Effect of acute exposure to nonylphenol on biochemical, hormonal, and hematological parameters and muscle tissues residues of Nile tilapia; Oreochromis niloticus

PubMed Central

Ismail, Hager Tarek H.; Mahboub, Heba Hassan H.

2016-01-01

Aim: This study was aimed to evaluate some biochemical, hormonal, hematological, and histopathological changes in Nile tilapia, Oreochromis niloticus, after acute exposure to nonylphenol (NP). In addition to detection of NP residues in the fish, muscle tissues for human health concern. Materials and Methods: A total of 90 apparently healthy Nile tilapia, O. niloticus, were randomly divided into three equal groups; each containing 30 fish (three replicates). Groups 1 and 2 kept as a control and solvent control (acetone), respectively, and Group 3 exposed to NP at a dose level of 500 µg/L water for 7 successive days. Blood and tissue samples were collected 2 times randomly from each group after 7 days from fish exposure to NP and 10 days from exposure stopping. Results: Fish exposed to NP Group 3 showed anorexia, sluggish movement, erythema of the skin, areas of scales loss, and hemorrhagic ulcers in some areas of body region leading to exposing the viscera. Biochemical results revealed a significant increase in serum total proteins and globulins levels, a highly significant increase in serum alanine aminotransferase and aspartate aminotransferase activities, triglycerides, cholesterol, and creatinine levels, insignificant increase in serum uric acid level, and a highly significant decrease in serum testosterone and estradiol-β17 levels in Group 3 in compare with the control group. Histopathological finding confirms these results. While hematological results of the same group revealed a significant increase in red blood cells count and packed cell volume value, insignificant increase in hemoglobin concentration, leukopenia, lymphopenia, and monocytopenia in compared with the control group. All of these changes appeared after 7 days from fish exposure to NP. Most of these alterations returned toward the normal level after 10 days from stopping exposure to NP. NP residues detected in fish muscle tissues of Group 3 during exposure and after stopping exposure to it. Conclusion: It is concluded that NP is a toxic pollutant and has an adverse effect on fish health and reproduction as well as accumulates in fish muscle tissues which may cause human health hazard. PMID:27397986

Epidemiology of hepatitis C virus exposure in Egypt: Opportunities for prevention and evaluation

PubMed Central

Miller, F DeWolfe; Elzalabany, Mahmoud S; Hassani, Sara; Cuadros, Diego F

2015-01-01

AIM: To critically evaluate the current epidemiology data on exposures, rather than infection, to hepatitis C virus (HCV) transmission and recommend epidemiologic strategies to fill gaps. METHODS: Standard methods for identifying and evaluating relevant epidemiologic literature and available data were used. RESULTS: There is a large body of literature on the epidemiology of HCV transmission in Egypt that collectively identifies ongoing iatrogenic exposures as the major driver for HCV transmission due to short comings in infection control and standard procedures. Additional epidemiologic studies on HCV transmission that requires the participation of human subject is unwarranted. Alternatively, very little literature was found on the epidemiology of exposure to HCV, infection control, and safe injection practices. The information that is available on patterns of HCV exposure shows high frequencies of inadequate infection control, problems in sterilization in health care facilities, low rates of hand washing, untrained personnel, lack of stated policies in facilities, HCV contamination of instruments and very large injection frequencies with low but very significant syringe and needle reuse. There is an important need to increase the number, size, and diversity of epidemiologic studies on HCV exposures, patterns of risk factors for infection, infection control, and safe injection practices. In addition to health care facilities evaluation, relevant knowledge attitude and practice studies are recommended. CONCLUSION: Epidemiologic methods on HCV exposure can be used to characterize the magnitude of exposures to HCV infection, target interventions to reduce exposures, and provide the best method for evaluating interventions by demonstrating the reduction of exposure to HCV infection. PMID:26668697

[Epidemiology of human rabies in China, 2016].

PubMed

Li, Y R; Zhu, L L; Zhu, W Y; Tao, X Y

2018-01-10

Objective: To understand the epidemiological characteristics of human rabies in China in 2016 and provide evidence for the control and prevention of human rabies. Methods: The incidence data of human rabies in China in 2016 were collected from national infectious disease reporting information management system. The surveillance data were collected from provinces of Shandong, Guizhou, Anhui, Hunan, Jiangsu and Guangxi Zhuang Autonomous Region. Excel 2013 software was used to process and summarize the data, the epidemiological characteristics of human rabies in China in 2016 were described by using indicators such as morbidity, mortality and constituent ratio. Results: A total of 644 human rabies cases were reported in 28 provinces in China in 2016, a decrease of 19.60% (157/801) compared with 2015. The provinces reporting high incidences of human rabies were Henan, Hunan, Guangxi and Guizhou, accounting for 39.44% (254/644) of the total cases. One case was reported in Qinghai province and Xinjiang Uygur Autonomous Region respectively. The male to female ratio of the cases was 2.14∶1 (439/205), and the majority of the patients were farmers (444/644). Surveillance points in 6 provinces reported 1 281 340 persons seeking post-exposure treatment, of whom 1 018 367 were treated for dog bite or scratch. A total of 764 234 persons completed the vaccination series, accounting for 63.90% (764 234/1 195 956) of the persons with grade Ⅱ and Ⅲ exposures, and 28.89% (165 677/573 571) of the persons with grade Ⅲ exposure were treated with passive immunization product. The average density of dogs in each surveillance area was 7.03/100 persons, the average canine immunization rate was 37.64%. Conclusion: The incidence of human rabies has remained decline in China in 2016, the number of the affected provinces has increased and that has the tendency of spreading to low-risk regions. The cases mainly occurred in men and farmers, and caused by dog bite or scratch. It is necessary to strengthen the health education about rabies prevention and control in rural areas and expand the coverage of canine immunization to prevent and control human rabies.

Epidemiology, Impact and Control of Rabies in Nepal: A Systematic Review

PubMed Central

Devleesschauwer, Brecht; Aryal, Arjun; Sharma, Barun Kumar; Ale, Anita; Declercq, Anne; Depraz, Stephanie; Gaire, Tara Nath; Gongal, Gyanendra; Karki, Surendra; Pandey, Basu Dev; Pun, Sher Bahadur; Duchateau, Luc; Dorny, Pierre; Speybroeck, Niko

2016-01-01

Background Rabies is a vaccine-preventable viral zoonosis belonging to the group of neglected tropical diseases. Exposure to a rabid animal may result in a fatal acute encephalitis if effective post-exposure prophylaxis is not provided. Rabies occurs worldwide, but its burden is disproportionately high in developing countries, including Nepal. We aimed to summarize current knowledge on the epidemiology, impact and control of rabies in Nepal. Methods We performed a systematic review of international and national scientific literature and searched grey literature through the World Health Organization Digital Library and the library of the National Zoonoses and Food Hygiene Research Centre, Nepal, and through searching Google and Google Scholar. Further data on animal and human rabies were obtained from the relevant Nepalese government agencies. Finally, we surveyed the archives of a Nepalese daily to obtain qualitative information on rabies in Nepal. Findings So far, only little original research has been conducted on the epidemiology and impact of rabies in Nepal. Per year, rabies is reported to kill about 100 livestock and 10–100 humans, while about 1,000 livestock and 35,000 humans are reported to receive rabies post-exposure prophylaxis. However, these estimates are very likely to be serious underestimations of the true rabies burden. Significant progress has been made in the production of cell culture-based anti-rabies vaccine and rabies immunoglobulin, but availability and supply remain a matter of concern, especially in remote areas. Different state and non-state actors have initiated rabies control activities over the years, but efforts typically remained focalized, of short duration and not harmonized. Communication and coordination between veterinary and human health authorities is limited at present, further complicating rabies control in Nepal. Important research gaps include the reporting biases for both human and animal rabies, the ecology of stray dog populations and the true contribution of the sylvatic cycle. Interpretation Better data are needed to unravel the true burden of animal and human rabies. More collaboration, both within the country and within the region, is needed to control rabies. To achieve these goals, high level political commitment is essential. We therefore propose to make rabies the model zoonosis for successful control in Nepal. PMID:26871689

First report of the concentrations and implications of DDT residues in chicken eggs from a malaria-controlled area.

PubMed

Bouwman, Hindrik; Bornman, Riana; van Dyk, Cobus; Barnhoorn, Irene

2015-10-01

In malaria-endemic areas, where DDT is still used for vector control by indoor residual spraying (IRS), the concentrations of DDT in human blood and breast milk are high, and there are indications of human health impacts. To identify the possible avenues of exposure reduction, we created the concept of a Total Homestead Environment Approach (THEA). THEA characterizes the interactions between DDT, humans, and the biota within and around homesteads. One dietary route of human exposure and uptake of DDT, namely, chicken egg consumption, has to our knowledge never been studied. The ΣDDT in eggs from a DDT-sprayed village ranged between 5200 and 48,000 ng/g wm (wet mass), with a median of 11,000 ng/g wm. On a lipid mass-basis (lm), the mean ΣDDT for eggs from the sprayed village was 100,000 ng/g lm. The maximum egg concentration observed was three orders of magnitude higher than the median. The acceptable daily intake (ADI) was not exceeded based on the consumption of three eggs per week for a 60 kg person. This equates to an intake of 0.089 g DDT per person per year. Chicken egg consumption is therefore a possible target for exposure reduction, probably best achieved by reducing the DDT concentrations in soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

The ABCs of Non-Toxic Pest Control.

ERIC Educational Resources Information Center

Cooper, Susan

1990-01-01

Although chemical-intensive pest control methods have proven reasonably effective, a growing awareness of health and environmental risks associated with pesticides has sharpened public interest in safer alternatives. An integrated pest management approach reduces risks from pests while minimizing human exposure and reducing the toxicity of applied…

The Pesticide Problem: Is Any Amount Safe?

ERIC Educational Resources Information Center

Cooper, Susan

1991-01-01

Discusses the use of integrated pest management to foster a safe school environment free from pesticides. This effective, environmentally sound system minimizes human exposure and reduces the toxicity of materials used to control pests. Parents, teachers, and students can educate themselves to improve school pest control practices. (SM)

Mitochondrial tolerance to single and repeat exposure to simulated sunlight in human epidermal and dermal skin cells.

PubMed

Kelly, J; Murphy, J E J

2016-12-01

Sunlight represents the primary threat to mitochondrial integrity in skin given the unique nature of the mitochondrial genome and its proximity to the electron transport chain. The accumulation of mitochondrial DNA (mtDNA) mutations is a key factor in many human pathologies and this is linked to key roles of mitochondrial function in terms of energy production and cell regulation. The main objective of this study was to evaluate solar radiation induced changes in mitochondrial integrity, function and dynamics in human skin cells using a Q-Sun solar simulator to deliver a close match to the intensity of summer sunlight. Spontaneously immortalised human skin epidermal keratinocytes (HaCaT) and Human Dermal Fibroblasts (HDFn) were divided into two groups. Group A were irradiated once and Group B twice 7days apart and evaluated using cell survival, viability and mitochondrial membrane potential (MMP) and mass at 1, 4 and 7days post one exposure for Group A and 1, 4, 7 and 14days post second exposure for Group B. Viability and survival of HaCaT and HDFn cells decreased after repeat exposure to Simulated Sunlight Irradiation (SSI) with no recovery. HDFn cells showed no loss in MMP after one or two exposures to SSI compared to HaCaT cells which showed a periodic loss of MMP after one exposure with a repeat exposure causing a dramatic decrease from which cells did not recover. Mitochondrial Mass in exposed HDFn cells was consistent with control after one or two exposures to SSI; however mitochondrial mass was significantly decreased in HaCaT cells. Data presented here suggests that mitochondria in epidermal cells are more sensitive to sunlight damage compared to mitochondria in dermal cells, despite their origin, confirming a skin layer specific sensitivity to sunlight, but not as expected. Copyright © 2016 Elsevier B.V. All rights reserved.

Toxicological characterization of the landfill leachate prior/after chemical and electrochemical treatment: a study on human and plant cells.

PubMed

Garaj-Vrhovac, Vera; Oreščanin, Višnja; Gajski, Goran; Gerić, Marko; Ruk, Damir; Kollar, Robert; Radić Brkanac, Sandra; Cvjetko, Petra

2013-10-01

In this research, toxicological safety of two newly developed methods for the treatment of landfill leachate from the Piškornica (Croatia) sanitary landfill was investigated. Chemical treatment procedure combined chemical precipitation with CaO followed by coagulation with ferric chloride and final adsorption by clinoptilolite. Electrochemical treatment approach included pretreatment with ozone followed by electrooxidation/electrocoagulation and final polishing by microwave irradiation. Cell viability of untreated/treated landfill leachate was examined using fluorescence microscopy. Cytotoxic effect of the original leachate was obtained for both exposure periods (4 and 24 h) while treated samples showed no cytotoxic effect even after prolonged exposure time. The potential DNA damage of the untreated/treated landfill leachate was evaluated by the comet assay and cytokinesis-block micronucleus (CBMN) assay using either human or plant cells. The original leachate exhibited significantly higher comet assay parameters compared to negative control after 24 h exposure. On the contrary, there was no significant difference between negative control and chemically/electrochemically treated leachate for any of the parameters tested. There was also no significant increase in either CBMN assay parameter compared to the negative control following the exposure of the lymphocytes to the chemically or electrochemically treated landfill leachate for both exposure periods while the original sample showed significantly higher number of micronuclei, nucleoplasmic bridges and nuclear buds for both exposure times. Results suggest that both methods are suitable for the treatment of such complex waste effluent due to high removal efficiency of all measured parameters and toxicological safety of the treated effluent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhanced constitutive invasion activity in human nontumorigenic keratinocytes exposed to a low level of barium for a long time.

PubMed

Thang, Nguyen D; Yajima, Ichiro; Ohnuma, Shoko; Ohgami, Nobutaka; Kumasaka, Mayuko Y; Ichihara, Gaku; Kato, Masashi

2015-02-01

We have recently demonstrated that exposure to barium for a short time (≤4 days) and at a low level (5 µM = 687 µg/L) promotes invasion of human nontumorigenic HaCaT cells, which have characteristics similar to those of normal keratinocytes, suggesting that exposure to barium for a short time enhances malignant characteristics. Here we examined the effect of exposure to low level of barium for a long time, a condition mimicking the exposure to barium through well water, on malignant characteristics of HaCaT keratinocytes. Constitutive invasion activity, focal adhesion kinase (FAK) protein expression and activity, and matrix metalloproteinase 14 (MMP14) protein expression in primary cultured normal human epidermal keratinocytes, HaCaT keratinocytes, and HSC5 and A431 human squamous cell carcinoma cells were augmented following an increase in malignancy grade of the cells. Constitutive invasion activity, FAK phosphorylation, and MMP14 expression levels of HaCaT keratinocytes after treatment with 5 µM barium for 4 months were significantly higher than those of control untreated HaCaT keratinocytes. Taken together, our results suggest that exposure to a low level of barium for a long time enhances constitutive malignant characteristics of HaCaT keratinocytes via regulatory molecules (FAK and MMP14) for invasion. © 2013 Wiley Periodicals, Inc.

Occupational asphalt is not associated with head and neck cancer

PubMed Central

Fogleman, E. V.; Eliot, M.; Michaud, D. S.; Nelson, H. H.; McClean, M. D.

2015-01-01

Background Epidemiologic studies that evaluate the relationship between occupational asphalt exposure and head and neck cancer have had a limited ability to control for known risk factors such as smoking, alcohol and human papillomavirus (HPV). Aims To better elucidate this relationship by including known risk factors in a large case–control study of head and neck squamous cell carcinoma (HNSCC) from the greater Boston area. Methods We analysed the relationship between occupational asphalt exposure and HNSCC among men in the Greater Boston area of Massachusetts. Analyses were conducted using unconditional multivariable logistic regression, performed with adjustments for age, race, education, smoking, alcohol consumption and HPV serology. Results There were 753 cases and 913 controls. No associations between HNSCC and occupational asphalt exposure (neither among ever-exposed nor by occupational duration) were observed for exposures in any occupation or those restricted to the construction industry. We also observed no associations in subgroup analyses of never-smokers and ever-smokers. Adjusting for known risk factors further reduced the estimated effect of asphalt exposure on HNSCC risk. Conclusions We found no evidence for an association between occupational asphalt exposure and HNSCC. The null findings from this well-controlled analysis could suggest that the risk estimates stemming from occupational cohort studies may be overestimated due to uncontrolled confounding and enhance the literature available for weighing cancer risk from occupational exposure to bitumen. PMID:26272381

Sex Specific Effect of Prenatal Testosterone on Language Lateralization in Children

ERIC Educational Resources Information Center

Lust, J. M.; Geuze, R. H.; Van de Beek, C.; Cohen-Kettenis, P. T.; Groothuis, A. G. G.; Bouma, A.

2010-01-01

Brain lateralization refers to the division of labour between the two hemispheres in controlling a wide array of functions and is remarkably well developed in humans. Based on sex differences in lateralization of handedness and language, several hypotheses have postulated an effect of prenatal exposure to testosterone on human lateralization…

Exposure to toxic waste sites: an investigative approach.

PubMed

Stehr-Green, P A; Lybarger, J A

1989-01-01

Improper dumping and storage of hazardous substances and whether these practices produce significant human exposure and health effects are growing concerns. A sequential approach has been used by the Centers for Disease Control and the Agency for Toxic Substances and Disease Registry in investigating potential exposure to and health effects resulting from environmental contamination with materials such as heavy metals, volatile organic compounds, and pesticide residues at sites throughout the United States. The strategy consists of four phases: site evaluation, pilot studies of exposure or health effects, analytic epidemiology studies, and public health surveillance. This approach offers a logical, phased strategy to use limited personnel and financial resources of local, State, national, or global health agency jurisdictions optimally in evaluating populations potentially exposed to hazardous materials in waste sites. Primarily, this approach is most helpful in identifying sites for etiologic studies and providing investigative leads to direct and focus these studies. The results of such studies provide information needed for making risk-management decisions to mitigate or eliminate human exposures and for developing interventions to prevent or minimize health problems resulting from exposures that already have occurred.

Pathways of human exposure to cobalt in Katanga, a mining area of the D.R. Congo.

PubMed

Cheyns, Karlien; Banza Lubaba Nkulu, Célestin; Ngombe, Léon Kabamba; Asosa, Jimmy Ngoy; Haufroid, Vincent; De Putter, Thierry; Nawrot, Tim; Kimpanga, Célestin Muleka; Numbi, Oscar Luboya; Ilunga, Benjamin Kabyla; Nemery, Benoit; Smolders, Erik

2014-08-15

Human exposure biomonitoring in the African Copperbelt (Katanga, southern D.R. Congo) revealed elevated cobalt (Co) exposure in the general population. This study was designed to identify the Co exposure routes for the non-occupationally exposed population in that area. The concentration of Co was measured in environmental and urine samples collected in urban and rural communities close to metal mining and/or refining plants, villages near a lake receiving effluents from metal refining plants, and control rural areas without industrial pollution. Drinking water, uncooked food items (maize flour, washed vegetables, fish and meat), indoor and outdoor dust samples were collected at each location. A food questionnaire was used to estimate dietary Co intake for adults and children. Geometric mean urine-Co (U-Co) concentrations were 4.5-fold (adults) and 6.6-fold (children) higher in the polluted than in the control area, with U-Co values being intermediate in the lakeside area. Average Co concentrations in environmental samples differed 6-40-fold between these areas. U-Co was positively correlated with most environmental Co concentrations, the highest correlations being found with Co in drinking water, vegetables and fruit. Estimated average total Co intake for adults was 63 (±42) μg/day in the control area, 94 (±55) μg/day in the lakeside villages and 570 (±100) μg Co/day in the polluted areas. U-Co was significantly related to modelled Co intake (R(2)=0.48, adults and R(2)=0.47, children; log-log relationship). Consumption of legumes, i.e. sweet potato leaves (polluted) and cereals+fish (lakeside) was the largest contributor to Co intake in adults, whereas dust ingestion appeared to contribute substantially in children in the polluted area. In conclusion, dietary Co is the main source of Co exposure in the polluted area and Co is efficiently transferred from soil and water in the human food chain. Copyright © 2014 Elsevier B.V. All rights reserved.

Extrapolation of plasma clearance to understand species differences in toxicokinetics of bisphenol A.

PubMed

Poet, Torka; Hays, Sean

2017-10-13

1. Understanding species differences in the toxicokinetics of bisphenol A (BPA) is central to setting acceptable exposure limits for human exposures to BPA. BPA toxicokinetics have been well studied, with controlled oral dosing studies in several species and across a wide dose range. 2. We analyzed the available toxicokinetic data for BPA following oral dosing to assess potential species differences and dose dependencies. BPA is rapidly conjugated and detoxified in all species. The toxicokinetics of BPA can be well described using non-compartmental analyses. 3. Several studies measured free (unconjugated) BPA in blood and reported area under the curve (AUC) of free BPA in blood of mice, rats, monkeys, chimpanzees and humans following controlled oral doses. Extrinsic clearance was calculated and analyzed across species and dose using allometric scaling. 4. The results indicate free BPA clearance is well described using allometric scaling with high correlation coefficients across all species and doses up to 10 mg/kg. The results indicate a human equivalent dose factor (HEDf) of 0.9 is appropriate for extrapolating a point of departure from mice and rats to a human equivalent dose (HED), thereby replacing default uncertainty factors for animal to human toxicokinetics.

An important date in rabies history.

PubMed

Dodet, Betty

2007-12-17

Rabies is estimated to cause 31,000 human deaths in Asia annually. Several recent events, including World Rabies Day have brought this neglected disease to the attention of the scientific community, governmental authorities, the media and the public. It is hoped that this will result in an increased collaboration between veterinary and human health authorities, and an involvement at all levels necessary for the control and elimination of rabies in dogs, the main reservoir and vector of rabies in Asia. Dog rabies elimination is considered as the most cost-effective solution to prevent rabies deaths in humans. Asian countries such as India and the Philippines have recently adopted the objective of eliminating rabies by 2020. To support World Rabies Day, the Asian Rabies Expert Bureau (AREB) had its 4th annual meeting from 5 to 7 September 2007, with the objective of debating strategies for lowering the human rabies toll. Human rabies deaths can already be prevented by improving the compliance to WHO post-exposure prophylaxis recommendations. In addition, in regions with a high incidence of canine rabies and where rabies control in dogs is not yet achieved or not effective, systematic pre-exposure vaccination of children who are the main victims of rabies, may prevent their premature deaths.

Factors that are associated with the risk of acquiring Plasmodium knowlesi malaria in Sabah, Malaysia: a case-control study protocol.

PubMed

Grigg, M J; William, T; Drakeley, C J; Jelip, J; von Seidlein, L; Barber, B E; Fornace, K M; Anstey, N M; Yeo, T W; Cox, J

2014-08-22

Plasmodium knowlesi has long been present in Malaysia, and is now an emerging cause of zoonotic human malaria. Cases have been confirmed throughout South-East Asia where the ranges of its natural macaque hosts and Anopheles leucosphyrus group vectors overlap. The majority of cases are from Eastern Malaysia, with increasing total public health notifications despite a concurrent reduction in Plasmodium falciparum and P. vivax malaria. The public health implications are concerning given P. knowlesi has the highest risk of severe and fatal disease of all Plasmodium spp in Malaysia. Current patterns of risk and disease vary based on vector type and competence, with individual exposure risks related to forest and forest-edge activities still poorly defined. Clustering of cases has not yet been systematically evaluated despite reports of peri-domestic transmission and known vector competence for human-to-human transmission. A population-based case-control study will be conducted over a 2-year period at two adjacent districts in north-west Sabah, Malaysia. Confirmed malaria cases presenting to the district hospital sites meeting relevant inclusion criteria will be requested to enrol. Three community controls matched to the same village as the case will be selected randomly. Study procedures will include blood sampling and administration of household and individual questionnaires to evaluate potential exposure risks associated with acquisition of P. knowlesi malaria. Secondary outcomes will include differences in exposure variables between P. knowlesi and other Plasmodium spp, risk of severe P. knowlesi malaria, and evaluation of P. knowlesi case clustering. Primary analysis will be per protocol, with adjusted ORs for exposure risks between cases and controls calculated using conditional multiple logistic regression models. This study has been approved by the human research ethics committees of Malaysia, the Menzies School of Health Research, Australia, and the London School of Hygiene and Tropical Medicine, UK. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Acrylamide exposure measured by food frequency questionnaire and hemoglobin adduct levels and prostate cancer risk in the Cancer of the Prostate in Sweden Study

PubMed Central

Wilson, Kathryn M.; Bälter, Katarina; Adami, Hans-Olov; Grönberg, Henrik; Vikström, Anna C.; Paulsson, Birgit; Törnqvist, Margareta; Mucci, Lorelei A.

2010-01-01

Acrylamide, a probable human carcinogen, is formed during the cooking of many commonly consumed foods. Data are scant on whether dietary acrylamide represents an important cancer risk in humans. We studied the association between acrylamide and prostate cancer risk using two measures of acrylamide exposure: intake from a food frequency questionnaire (FFQ) and acrylamide adducts to hemoglobin. We also studied the correlation between these two exposure measures. We used data from the population-based case-control study Cancer of the Prostate in Sweden (CAPS). Dietary data was available for 1499 cases and 1118 controls. Hemoglobin adducts of acrylamide were measured in blood samples from a subset of 170 cases and 161 controls. We calculated odds ratios (ORs) for the risk of prostate cancer in high versus low quantiles of acrylamide exposure using logistic regression. The correlation between FFQ acrylamide intake and acrylamide adducts in non-smokers was 0.25 (95% confidence interval: 0.14–0.35), adjusted for age, region, energy intake, and laboratory batch. Among controls the correlation was 0.35 (95% CI: 0.21–0.48); among cases it was 0.15 (95% CI: 0.00–0.30). The OR of prostate cancer for the highest versus lowest quartile of acrylamide adducts was 0.93 (95% CI: 0.47–1.85, p-value for trend=0.98). For FFQ acrylamide, the OR of prostate cancer for the highest versus lowest quintile was 0.97 (95% CI: 0.75–1.27, p trend=0.67). No significant associations were found between acrylamide exposure and risk of prostate cancer by stage, grade, or PSA level. Acrylamide adducts to hemoglobin and FFQ-measured acrylamide intake were moderately correlated. Neither measure of acrylamide exposure – hemoglobin adducts or FFQ – was associated with risk of prostate cancer. PMID:19142870

77 FR 26456 - Carfentrazone-ethyl; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-04

...: This regulation establishes tolerances for residues of carfentrazone-ethyl in or on crop group 18, non... Registration for Application to the Non-grass Animal Feed Crop Group 18. Human-Health Risk Assessment'' pp. 30...-occupational, non-dietary exposure (e.g., for lawn and garden pest control, indoor pest control, termiticides...

Prenatal Estrogens and the Development of Homosexual Orientation.

ERIC Educational Resources Information Center

Meyer-Bahlburg, Heino F. L.; And Others

1995-01-01

Examines the hypothesis that prenatal estrogens contribute to the development of human sexual orientation. Several groups of women with a history of prenatal exposure to diethylstilbestrol (DES) were compared with several samples of control women. Findings showed that more DES-exposed women than controls were rated as bisexual or homosexual,…

Critical evaluation of the cancer risk of dibromochloropropane (DBCP).

PubMed

Clark, Heather A; Snedeker, Suzanne M

2005-01-01

Dibromochloropropane (1,2-dibromo-3-chloropropane, DBCP), a pesticide used widely for over 20 years to control nematodes on crops, turf and in nurseries, was banned by the United States Environmental Protection Agency (US EPA) in 1977 because of evidence of infertility in men and induction of a variety of tumors in laboratory animals. Despite the ban on the use of DBCP, this pesticide remains persistent in soil and continues to be detected as a groundwater contaminant in areas of past high use, in particular California's Central Valley. In this review, we present a critical evaluation of the available scientific literature on the potential for DBCP to affect cancer risk, including the results of animal cancer bioassays, human epidemiological studies and in vitro and in vivo genotoxicity studies. In addition, we provide updated information on DBCP chemistry and metabolism, production and past use, current regulations, its environmental fate, potential for human exposure and current remediation efforts. Results from long-term cancer bioassays in rodents show a statistically significant increase in the incidence of malignant and benign mammary gland tumors in female rats treated orally with DBCP compared to controls and some evidence of increased incidence of mammary fibroadenomas in DBCP low-dose treated female rats exposed by inhalation. Significantly increased incidence of tumors of the forestomach occurred in both sexes of rats and mice treated orally. Rats exposed to DBCP by inhalation showed significant increases in tumors of the tunica vaginalis in males; tumors of the pharynx and adrenal gland in females; and tumors of the tongue, nasal turbinate and nasal cavity in both sexes compared to controls. Male and female mice exposed to DBCP by inhalation experienced increased tumor incidence in the lungs and nasal cavity compared to controls. Significant increases in tumors of the lung and forestomach have also been reported in female mice treated by a dermal route. Although high mortality rates in both rat and mouse bioassays limited the ability to detect tumors late in life, the induction of a variety of tumors by multiple routes of exposure in two rodent species provides clear evidence of a DBCP tumorigenic response. In vitro, in vivo and human genotoxicity studies indicate that DBCP is capable of acting as a mutagen and clastogen. Few studies have been conducted to assess whether DBCP workplace or drinking water exposures affect cancer risk in humans. While case-control, cohort and ecological epidemiology studies have not found significant, positive associations between DBCP exposure and cancer in exposed populations, these studies have numerous limitations including small numbers of participants, a lack of control for confounding factors, lack of exposure information on DBCP and other chemicals and short follow-up times. Given the persistent nature of DBCP contamination in areas of past use, efforts should be made to continue remediation efforts and follow previously exposed populations for development of certain human cancers, including breast, ovarian, stomach, respiratory, oral and nasal cancers, among others.

Cotinine analytical workshop report: consideration of analytical methods for determining cotinine in human body fluids as a measure of passive exposure to tobacco smoke.

PubMed Central

Watts, R R; Langone, J J; Knight, G J; Lewtas, J

1990-01-01

A two-day technical workshop was convened November 10-11, 1986, to discuss analytical approaches for determining trace amounts of cotinine in human body fluids resulting from passive exposure to environmental tobacco smoke (ETS). The workshop, jointly sponsored by the U.S. Environmental Protection Agency and Centers for Disease Control, was attended by scientists with expertise in cotinine analytical methodology and/or conduct of human monitoring studies related to ETS. The workshop format included technical presentations, separate panel discussions on chromatography and immunoassay analytical approaches, and group discussions related to the quality assurance/quality control aspects of future monitoring programs. This report presents a consensus of opinion on general issues before the workshop panel participants and also a detailed comparison of several analytical approaches being used by the various represented laboratories. The salient features of the chromatography and immunoassay analytical methods are discussed separately. PMID:2190812

Alterations in the Spectrum of Spontaneous Rifampicin-Resistance Mutations in the Bacillus subtilis rpoB Gene after Cultivation in the Human Spaceflight Environment.

PubMed

Fajardo-Cavazos, Patricia; Leehan, Joshua D; Nicholson, Wayne L

2018-01-01

The effect of Bacillus subtilis exposure to the human spaceflight environment on growth, mutagenic frequency, and spectrum of mutations to rifampicin resistance (Rif R ) was investigated. B. subtilis cells were cultivated in Biological Research in Canister-Petri Dish Fixation Units (BRIC-PDFUs) on two separate missions to the International Space Station (ISS), dubbed BRIC-18 and BRIC-21, with matching asynchronous ground controls. No statistically significant difference in either growth or in the frequency of mutation to Rif R was found in either experiment. However, nucleotide sequencing of the Rif R regions of the rpoB gene from Rif R mutants revealed dramatic differences in the spectrum of mutations between flight (FL) and ground control (GC) samples, including two newly discovered rpoB alleles in the FL samples (Q137R and L489S). The results strengthen the idea that exposure to the human spaceflight environment causes unique stresses on bacteria, leading to alterations in their mutagenic potential.

Phosphorylation and gene expression of p53 are not affected in human cells exposed to 2.1425 GHz band CW or W-CDMA modulated radiation allocated to mobile radio base stations.

PubMed

Hirose, H; Sakuma, N; Kaji, N; Suhara, T; Sekijima, M; Nojima, T; Miyakoshi, J

2006-09-01

A large-scale in vitro study focusing on low-level radiofrequency (RF) fields from mobile radio base stations employing the International Mobile Telecommunication 2000 (IMT-2000) cellular system was conducted to test the hypothesis that modulated RF fields induce apoptosis or other cellular stress response that activate p53 or the p53-signaling pathway. First, we evaluated the response of human cells to microwave exposure at a specific absorption rate (SAR) of 80 mW/kg, which corresponds to the limit of the average whole-body SAR for general public exposure defined as a basic restriction by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. Second, we investigated whether continuous wave (CW) and wideband code division multiple access (W-CDMA) modulated signal RF fields at 2.1425 GHz induced apoptosis or any signs of stress. Human glioblastoma A172 cells were exposed to W-CDMA radiation at SARs of 80, 250, and 800 mW/kg, and CW radiation at 80 mW/kg for 24 or 48 h. Human IMR-90 fibroblasts from fetal lungs were exposed to both W-CDMA and CW radiation at a SAR of 80 mW/kg for 28 h. Under the RF field exposure conditions described above, no significant differences in the percentage of apoptotic cells were observed between the test groups exposed to RF signals and the sham-exposed negative controls, as evaluated by the Annexin V affinity assay. No significant differences in expression levels of phosphorylated p53 at serine 15 or total p53 were observed between the test groups and the negative controls by the bead-based multiplex assay. Moreover, microarray hybridization and real-time RT-PCR analysis showed no noticeable differences in gene expression of the subsequent downstream targets of p53 signaling involved in apoptosis between the test groups and the negative controls. Our results confirm that exposure to low-level RF signals up to 800 mW/kg does not induce p53-dependent apoptosis, DNA damage, or other stress response in human cells.

Management of Occupational Exposure to Engineered Nanoparticles Through a Chance-Constrained Nonlinear Programming Approach

PubMed Central

Chen, Zhi; Yuan, Yuan; Zhang, Shu-Shen; Chen, Yu; Yang, Feng-Lin

2013-01-01

Critical environmental and human health concerns are associated with the rapidly growing fields of nanotechnology and manufactured nanomaterials (MNMs). The main risk arises from occupational exposure via chronic inhalation of nanoparticles. This research presents a chance-constrained nonlinear programming (CCNLP) optimization approach, which is developed to maximize the nanaomaterial production and minimize the risks of workplace exposure to MNMs. The CCNLP method integrates nonlinear programming (NLP) and chance-constrained programming (CCP), and handles uncertainties associated with both the nanomaterial production and workplace exposure control. The CCNLP method was examined through a single-walled carbon nanotube (SWNT) manufacturing process. The study results provide optimal production strategies and alternatives. It reveal that a high control measure guarantees that environmental health and safety (EHS) standards regulations are met, while a lower control level leads to increased risk of violating EHS regulations. The CCNLP optimization approach is a decision support tool for the optimization of the increasing MNMS manufacturing with workplace safety constraints under uncertainties. PMID:23531490

Oxidative stress in the blood of farm workers following intensive pesticide exposure.

PubMed

Ogut, Serdal; Gultekin, Fatih; Kisioglu, A Nesimi; Kucukoner, Erdoğan

2011-10-01

The aim of this study was to evaluate oxidative stress in workers who formulate organophosphate, synthetic pyrethroid and carbamate pesticides. In this survey, blood erythrocytes from a group of 94 pesticide-formulating workers (at least 5-years experience in pest-control in apple and cherry production) and 45 control subjects were examined for oxidative stress parameters. The control group was composed of 45 healthy people living in the same region with no exposure to pesticides. Lipid peroxidation level, catalase, superoxide dismutase and glutathione peroxidase activities in erythrocytes were analysed as biomarkers of oxidative stress. In addition, the acetylcholinesterase activity was measured as a biomarker of toxicity. Results indicated that chronic exposure to organophosphate, synthetic pyrethroid and carbamate pesticides were associated with increased activities of catalase, SOD and lipid peroxidation in erythrocytes (p < 0.05). Acetylcholinesterase activity did not show any significant differences between the two groups (p > 0.05). It is concluded that human chronic exposure to pesticides may result in stimulated antioxidant enzymes.

Management of occupational exposure to engineered nanoparticles through a chance-constrained nonlinear programming approach.

PubMed

Chen, Zhi; Yuan, Yuan; Zhang, Shu-Shen; Chen, Yu; Yang, Feng-Lin

2013-03-26

Critical environmental and human health concerns are associated with the rapidly growing fields of nanotechnology and manufactured nanomaterials (MNMs). The main risk arises from occupational exposure via chronic inhalation of nanoparticles. This research presents a chance-constrained nonlinear programming (CCNLP) optimization approach, which is developed to maximize the nanaomaterial production and minimize the risks of workplace exposure to MNMs. The CCNLP method integrates nonlinear programming (NLP) and chance-constrained programming (CCP), and handles uncertainties associated with both the nanomaterial production and workplace exposure control. The CCNLP method was examined through a single-walled carbon nanotube (SWNT) manufacturing process. The study results provide optimal production strategies and alternatives. It reveal that a high control measure guarantees that environmental health and safety (EHS) standards regulations are met, while a lower control level leads to increased risk of violating EHS regulations. The CCNLP optimization approach is a decision support tool for the optimization of the increasing MNMS manufacturing with workplace safety constraints under uncertainties.

Cadmium exposure and risk of pancreatic cancer: A meta-analysis of prospective cohort studies and case-control studies among individuals without occupational exposure history

PubMed Central

Chen, Cheng; Xun, Pengcheng; Nishijo, Muneko; Sekikawa, Akira

2015-01-01

Pancreatic cancer is one of the most deadly types of cancer for both genders. Classified as a human carcinogen, cadmium has been related to diverse cancers. However, the association between cadmium exposure and the risk of pancreatic cancer is still unclear. We quantitatively reviewed the observational studies on the association of cadmium exposure with pancreatic cancer risk among individuals without occupational exposure history published through July 2014 in PubMed by using a fixed–effects model. Four prospective cohort studies (112,934 participants with 335 events) and two case-control studies (177 cases and 539 controls) were identified. The summarized relative risk (RR) with a 95% confidence interval (CI) was 2.05 (95% CI=1.58 – 2.66), comparing the highest to the lowest category of cadmium exposure. This positive association persisted in men (RR=1.78; 95% CI=1.04 – 3.05), but not in women (RR=1.02; 95% CI=0.63 – 1.65). Further research is needed to provide more solid evidence on the association of cadmium exposure with pancreatic cancer risk and to elucidate the underlying biological mechanism of the potential gender difference. PMID:26423282

Cadmium exposure and risk of pancreatic cancer: a meta-analysis of prospective cohort studies and case-control studies among individuals without occupational exposure history.

PubMed

Chen, Cheng; Xun, Pengcheng; Nishijo, Muneko; Sekikawa, Akira; He, Ka

2015-11-01

Pancreatic cancer is one of the most deadly types of cancer for both genders. Classified as a human carcinogen, cadmium has been related to diverse cancers. However, the association between cadmium exposure and the risk of pancreatic cancer is still unclear. We quantitatively reviewed the observational studies on the association of cadmium exposure with pancreatic cancer risk among individuals without occupational exposure history published through July 2014 in PubMed by using a fixed-effect model. Four prospective cohort studies (112,934 participants with 335 events) and two case-control studies (177 cases and 539 controls) were identified. The summarized relative risk (RR) with a 95% confidence interval (CI) was 2.05 (95% CI = 1.58-2.66), comparing the highest to the lowest category of cadmium exposure. This positive association persisted in men (RR = 1.78, 95% CI = 1.04-3.05) but not in women (RR = 1.02, 95% CI = 0.63-1.65). Further research is needed to provide more solid evidence on the association of cadmium exposure with pancreatic cancer risk and to elucidate the underlying biological mechanism of the potential gender difference.

Behavioral Science as a New Frontier for Transformational ...

EPA Pesticide Factsheets

Over the last 40 years, tremendous progress has been made toward protecting our life-sustaining resources of air, water, and land and improving ecosystems and public health despite increasing population pressures. Many disciplines have provided the scientific underpinnings for this progress, but perhaps none have been more influential than exposure science. Exposure science has fostered a receptor- rather than source-based perspective regarding strategies for monitoring and controlling pollution to protect public health and the environment. We have achieved many gains through control of far-field sources. Near-field sources related to consumer products and activities in the home, vehicle, school, and work environments present the next challenge. These near-field sources tend to dominate our exposures and are direct results of our behaviors in purchasing and using consumer products. Therefore, these types of sources are less amenable to traditional regulatory approaches for exposure reduction. Behavior determines not only the presence or absence of consumer product and use, but also the details that largely define critical chemical exposure metrics including amount, concentration, frequency, duration, and pathway of exposure. Thus, it is becoming increasingly evident that in order to both predict and control near-field chemical exposures, we need to better understand human behavior and the knowledge, attitudes and beliefs that underlie consumer product rel

New Rodent Population Models May Inform Human Health Risk Assessment and Identification of Genetic Susceptibility to Environmental Exposures.

PubMed

Harrill, Alison H; McAllister, Kimberly A

2017-08-15

This paper provides an introduction for environmental health scientists to emerging population-based rodent resources. Mouse reference populations provide an opportunity to model environmental exposures and gene-environment interactions in human disease and to inform human health risk assessment. This review will describe several mouse populations for toxicity assessment, including older models such as the Mouse Diversity Panel (MDP), and newer models that include the Collaborative Cross (CC) and Diversity Outbred (DO) models. This review will outline the features of the MDP, CC, and DO mouse models and will discuss published case studies investigating the use of these mouse population resources in each step of the risk assessment paradigm. These unique resources have the potential to be powerful tools for generating hypotheses related to gene-environment interplay in human disease, performing controlled exposure studies to understand the differential responses in humans for susceptibility or resistance to environmental exposures, and identifying gene variants that influence sensitivity to toxicity and disease states. These new resources offer substantial advances to classical toxicity testing paradigms by including genetically sensitive individuals that may inform toxicity risks for sensitive subpopulations. Both in vivo and complementary in vitro resources provide platforms with which to reduce uncertainty by providing population-level data around biological variability. https://doi.org/10.1289/EHP1274.

New Rodent Population Models May Inform Human Health Risk Assessment and Identification of Genetic Susceptibility to Environmental Exposures

PubMed Central

Harrill, Alison H.

2017-01-01

Background: This paper provides an introduction for environmental health scientists to emerging population-based rodent resources. Mouse reference populations provide an opportunity to model environmental exposures and gene–environment interactions in human disease and to inform human health risk assessment. Objectives: This review will describe several mouse populations for toxicity assessment, including older models such as the Mouse Diversity Panel (MDP), and newer models that include the Collaborative Cross (CC) and Diversity Outbred (DO) models. Methods: This review will outline the features of the MDP, CC, and DO mouse models and will discuss published case studies investigating the use of these mouse population resources in each step of the risk assessment paradigm. Discussion: These unique resources have the potential to be powerful tools for generating hypotheses related to gene–environment interplay in human disease, performing controlled exposure studies to understand the differential responses in humans for susceptibility or resistance to environmental exposures, and identifying gene variants that influence sensitivity to toxicity and disease states. Conclusions: These new resources offer substantial advances to classical toxicity testing paradigms by including genetically sensitive individuals that may inform toxicity risks for sensitive subpopulations. Both in vivo and complementary in vitro resources provide platforms with which to reduce uncertainty by providing population-level data around biological variability. https://doi.org/10.1289/EHP1274 PMID:28886592

Acute Exposure to Stress Improves Performance in Trace Eyeblink Conditioning and Spatial Learning Tasks in Healthy Men

ERIC Educational Resources Information Center

Duncko, Roman; Cornwell, Brian; Cui, Lihong; Merikangas, Kathleen R.; Grillon, Christian

2007-01-01

The present study investigated the effects of acute stress exposure on learning performance in humans using analogs of two paradigms frequently used in animals. Healthy male participants were exposed to the cold pressor test (CPT) procedure, i.e., insertion of the dominant hand into ice water for 60 sec. Following the CPT or the control procedure,…

Human milk and infant formula can induce in vitro adipocyte differentiation in murine 3T3-L1 preadipocytes.

PubMed

Lyle, R E; Corley, J D; McGehee, R E

1998-11-01

The potential of infant diet to influence fat cell development has largely been examined in clinical studies with conflicting results. In this study, the direct effects of two standard infant formulas, Enfamil and Similac, as well as human milk were examined using a well characterized model of adipocyte differentiation, the 3T3-L1 murine preadipocyte cell line. After exposure to a hormonal regimen of insulin, dexamethasone, and 1-methyl-3-isobutylmethylxanthine, these cells undergo a mitotic expansion phase followed by terminal differentiation. On d 4 of hormonal exposure, greater than 95% of 3T3-L1 cells exhibit the morphologic and biochemical characteristics of mature adipocytes. In this study, cells were exposed to control medium, or control medium supplemented with either 10% Enfamil, 10% Similac, 10% human milk (skim or whole), or the standard hormonal regimen. Oil Red O-detectable lipid accumulation, immunocytochemical cell proliferation assays, and activated expression of adipocyte differentiation-specific mRNAs by Northern blot analysis were used to assess the effects of treatment on adipocyte differentiation. Results from each level of assessment revealed that both Enfamil and human milk were as effective as the standard hormonal regimen at stimulating adipocyte differentiation. In contrast, results from treatment with Similac or human skim milk were indistinguishable from control unstimulated cells. This study, demonstrating that Enfamil and human milk are capable of independently inducing in vitro adipocyte differentiation, suggests that diet during infancy could influence body fat development.

Application of the Navigation Guide systematic review methodology to the evidence for developmental and reproductive toxicity of triclosan.

PubMed

Johnson, Paula I; Koustas, Erica; Vesterinen, Hanna M; Sutton, Patrice; Atchley, Dylan S; Kim, Allegra N; Campbell, Marlissa; Donald, James M; Sen, Saunak; Bero, Lisa; Zeise, Lauren; Woodruff, Tracey J

2016-01-01

There are reports of developmental and reproductive health effects associated with the widely used biocide triclosan. Apply the Navigation Guide systematic review methodology to answer the question: Does exposure to triclosan have adverse effects on human development or reproduction? We applied the first 3 steps of the Navigation Guide methodology: 1) Specify a study question, 2) Select the evidence, and 3) Rate quality and strength of the evidence. We developed a protocol, conducted a comprehensive search of the literature, and identified relevant studies using pre-specified criteria. We assessed the number and type of all relevant studies. We evaluated each included study for risk of bias and rated the quality and strength of the evidence for the selected outcomes. We conducted a meta-analysis on a subset of suitable data. We found 4282 potentially relevant records, and 81 records met our inclusion criteria. Of the more than 100 endpoints identified by our search, we focused our evaluation on hormone concentration outcomes, which had the largest human and non-human mammalian data set. Three human studies and 8 studies conducted in rats reported thyroxine levels as outcomes. The rat data were amenable to meta-analysis. Because only one of the human thyroxine studies quantified exposure, we did not conduct a meta-analysis of the human data. Through meta-analysis of the data for rats, we estimated for prenatal exposure a 0.09% (95% CI: -0.20, 0.02) reduction in thyroxine concentration per mg triclosan/kg-bw in fetal and young rats compared to control. For postnatal exposure we estimated a 0.31% (95% CI: -0.38, -0.23) reduction in thyroxine per mg triclosan/kg-bw, also compared to control. Overall, we found low to moderate risk of bias across the human studies and moderate to high risk of bias across the non-human studies, and assigned a "moderate/low" quality rating to the body of evidence for human thyroid hormone alterations and a "moderate" quality rating to the body of evidence for non-human thyroid hormone alterations. Based on this application of the Navigation Guide systematic review methodology, we concluded that there was "sufficient" non-human evidence and "inadequate" human evidence of an association between triclosan exposure and thyroxine concentrations, and consequently, triclosan is "possibly toxic" to reproductive and developmental health. Thyroid hormone disruption is an upstream indicator of developmental toxicity. Additional endpoints may be identified as being of equal or greater concern as other data are developed or evaluated. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Application of the Navigation Guide Systematic Review Methodology to the Evidence for Developmental and Reproductive Toxicity of Triclosan

PubMed Central

Johnson, Paula I.; Koustas, Erica; Vesterinen, Hanna M.; Sutton, Patrice; Atchley, Dylan S.; Kim, Allegra N.; Campbell, Marlissa; Donald, James M.; Sen, Saunak; Bero, Lisa; Zeise, Lauren; Woodruff, Tracey J.

2016-01-01

Background There are reports of developmental and reproductive health effects associated with the widely used biocide triclosan. Objective Apply the Navigation Guide systematic review methodology to answer the question: Does exposure to triclosan have adverse effects on human development or reproduction? Methods We applied the first 3 steps of the Navigation Guide methodology: 1) Specify a study question, 2) Select the evidence, and 3) Rate quality and strength of the evidence. We developed a protocol, conducted a comprehensive search of the literature, and identified relevant studies using pre-specified criteria. We assessed the number and type of all relevant studies. We evaluated each included study for risk of bias and rated the quality and strength of the evidence for the selected outcomes. We conducted a meta-analysis on a subset of suitable data. Results We found 4,282 potentially relevant records, and 81 records met our inclusion criteria. Of the more than 100 endpoints identified by our search, we focused our evaluation on hormone concentration outcomes, which had the largest human and non-human mammalian data set. Three human studies and 8 studies conducted in rats reported thyroxine levels as outcomes. The rat data were amenable to meta-analysis. Because only one of the human thyroxine studies quantified exposure, we did not conduct a meta-analysis of the human data. Through meta-analysis of the data for rats, we estimated for prenatal exposure a 0.09% (95% CI: −0.20, 0.02) reduction in thyroxine concentration per mg triclosan/kg-bw in fetal and young rats compared to control. For postnatal exposure we estimated a 0.31% (95% CI: −0.38, −0.23) reduction in thyroxine per mg triclosan/kg-bw, also compared to control. Overall we found low to moderate risk of bias across the human studies and moderate to high risk of bias across the non-human studies, and assigned a “moderate/low” quality rating to the body of evidence for human thyroid hormone alterations and a “moderate” quality rating to the body of evidence for non-human thyroid hormone alterations. Conclusion Based on this application of the Navigation Guide systematic review methodology, we concluded that there was “sufficient” non-human evidence and “inadequate” human evidence of an association between triclosan exposure and thyroxine concentrations, and consequently, triclosan is “possibly toxic” to reproductive and developmental health. Thyroid hormone disruption is an upstream indicator of developmental toxicity. Additional endpoints may be identified as being of equal or greater concern as other data are developed or evaluated. PMID:27156197

Benefits of Stimulus Exposure: Developmental Learning Independent of Task Performance

PubMed Central

Green, David B.; Ohlemacher, Jocelyn; Rosen, Merri J.

2016-01-01

Perceptual learning (training-induced performance improvement) can be elicited by task-irrelevant stimulus exposure in humans. In contrast, task-irrelevant stimulus exposure in animals typically disrupts perception in juveniles while causing little to no effect in adults. This may be due to the extent of exposure, which is brief in humans while chronic in animals. Here we assessed the effects of short bouts of passive stimulus exposure on learning during development in gerbils, compared with non-passive stimulus exposure (i.e., during testing). We used prepulse inhibition of the acoustic startle response, a method that can be applied at any age, to measure gap detection thresholds across four age groups, spanning development. First, we showed that both gap detection thresholds and gap detection learning across sessions displayed a long developmental trajectory, improving throughout the juvenile period. Additionally, we demonstrated larger within- and across-animal performance variability in younger animals. These results are generally consistent with results in humans, where there are extended developmental trajectories for both the perception of temporally-varying signals, and the effects of perceptual training, as well as increased variability and poorer performance consistency in children. We then chose an age (mid-juveniles) that displayed clear learning over sessions in order to assess effects of brief passive stimulus exposure on this learning. We compared learning in mid-juveniles exposed to either gap detection testing (gaps paired with startles) or equivalent gap exposure without testing (gaps alone) for three sessions. Learning was equivalent in both these groups and better than both naïve age-matched animals and controls receiving no gap exposure but only startle testing. Thus, short bouts of exposure to gaps independent of task performance is sufficient to induce learning at this age, and is as effective as gap detection testing. PMID:27378837

Brominated flame retardants and seafood safety: a review.

PubMed

Cruz, Rebeca; Cunha, Sara C; Casal, Susana

2015-04-01

Brominated flame retardants (BFRs), frequently applied to industrial and household products to make them less flammable, are highly persistent in the environment and cause multi-organ toxicity in human and wildlife. Based on the review of BFRs presence in seafood published from 2004 to 2014, it is clear that such pollutants are not ideally controlled as the surveys are too restricted, legislation inexistent for some classes, the analytical methodologies diversified, and several factors as food processing and eating habits are generally overlooked. Indeed, while a seafood rich diet presents plenty of nutritional benefits, it can also represent a potential source of these environmental contaminants. Since recent studies have shown that dietary intake constitutes a main route of human exposure to BFRs, it is of major importance to review and enhance these features, since seafood constitutes a chief pathway for human exposure and biomagnification of priority environmental contaminants. In particular, more objective studies focused on the variability factors behind contamination levels, and subsequent human exposure, are necessary to support the necessity for more restricted legislation worldwide. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Role of Environmental Reservoirs in Human Campylobacteriosis

PubMed Central

Whiley, Harriet; van den Akker, Ben; Giglio, Steven; Bentham, Richard

2013-01-01

Campylobacteriosis is infection caused by the bacteria Campylobacter spp. and is considered a major public health concern. Campylobacter spp. have been identified as one of the most common causative agents of bacterial gastroenteritis. They are typically considered a foodborne pathogen and have been shown to colonise the intestinal mucosa of all food-producing animals. Much emphasis has been placed on controlling the foodborne pathway of exposure, particularly within the poultry industry, however, other environmental sources have been identified as important contributors to human infection. This paper aims to review the current literature on the sources of human exposure to Campylobacter spp. and will cover contaminated poultry, red meat, unpasteurised milk, unwashed fruit and vegetables, compost, wild bird faeces, sewage, surface water, ground water and drinking water. A comparison of current Campylobacter spp. identification methods from environmental samples is also presented. The review of literature suggests that there are multiple and diverse sources for Campylobacter infection. Many environmental sources result in direct human exposure but also in contamination of the food processing industry. This review provides useful information for risk assessment. PMID:24217177

First attempt to validate the gSG6-P1 salivary peptide as an immuno-epidemiological tool for evaluating human exposure to Anopheles funestus bites.

PubMed

Poinsignon, Anne; Samb, Badara; Doucoure, Souleymane; Drame, Papa-Makhtar; Sarr, Jean Biram; Sow, Cheikh; Cornelie, Sylvie; Maiga, Sophie; Thiam, Cheikh; Rogerie, François; Guindo, Sohidou; Hermann, Emmanuel; Simondon, François; Dia, Ibrahima; Riveau, Gilles; Konate, Lassana; Remoue, Franck

2010-10-01

The development of a biomarker of exposure based on the evaluation of the human antibody response specific to Anopheles salivary proteins seems promising in improving malaria control. The IgG response specific to the gSG6-P1 peptide has already been validated as a biomarker of An. gambiae exposure. This study represents a first attempt to validate the gSG6-P1 peptide as an epidemiological tool evaluating exposure to An. funestus bites, the second main malaria vector in sub-Saharan Africa. A multi-disciplinary survey was performed in a Senegalese village where An. funestus represents the principal anopheline species. The IgG antibody level specific to gSG6-P1 was evaluated and compared in the same children before, at the peak and after the rainy season. Two-thirds of the children developed a specific IgG response to gSG6-P1 during the study period and--more interestingly--before the rainy season, when An. funestus was the only anopheline species reported. The specific IgG response increased during the An. funestus exposure season, and a positive association between the IgG level and the level of exposure to An. funestus bites was observed. The results suggest that the evaluation of the IgG response specific to gSG6-P1 in children could also represent a biomarker of exposure to An. funestus bites. The availability of such a biomarker evaluating the exposure to both main Plasmodium falciparum vectors in Africa could be particularly relevant as a direct criterion for the evaluation of the efficacy of vector control strategies. © 2010 Blackwell Publishing Ltd.

Retrospective: animal attacks and rabies exposures in Thai children.

PubMed

Sriaroon, Chakrapol; Sriaroon, Panida; Daviratanasilpa, Svastijaya; Khawplod, Pakamatz; Wilde, Henry

2006-09-01

Over 50% of animal bites and potential rabies exposures in Thailand are in children and they also have the more severe injuries due to inexperience, smaller size and less ability to fend off attacks. Potential rabies exposures and animal bites are common in Thailand. Majority of these are in children where the extent of the injuries is also much more severe. The bitten areas correlate to the age of the children and level of the bitten animal head. These are areas noted for a higher risk of infection with rabies virus and shorter incubation periods. The vast majority of bites are due to dogs (86%) of which 74.6% are stray or community-owned animals. The prevalence of dog bites shows no seasonal variation in adults but there are two peaks during school vacation period for children. Extensive educational efforts directed at the Thai public are responsible for the rapid presentation of victims for post-exposure treatment. The dramatic reduction of human rabies deaths in Thailand during the last decades was achieved largely by the provision of expensive WHO standard post-exposure treatment, utilizing modern tissue culture vaccines and immunoglobulins. Canine and feline rabies is nevertheless still endemic and not likely to be controlled or eliminated till sustainable humane methods of dog population control and comprehensive countrywide canine rabies vaccination become possible through government policy.

Symptomatic effects of exposure to diluted air sampled from a swine confinement atmosphere on healthy human subjects.

PubMed

Schiffman, Susan S; Studwell, Clare E; Landerman, Lawrence R; Berman, Katherine; Sundy, John S

2005-05-01

Aerial emissions from a swine house at North Carolina State University's field laboratory were diluted to a level that could occur at varying distances downwind from a confined animal feeding operation (CAFO) both within and beyond the property line, and these emissions were delivered to an environmental exposure chamber. The study design consisted of two 1-hr sessions, one in which 48 healthy human adult volunteers were exposed to diluted swine air and another in which they were exposed to clean air (control). Objective measures of blood pressure, temperature, heart rate, respiratory rate, lung function, nasal inflammation, secretory immunity, mood, attention, and memory were correlated with objective measures of air quality. Ratings of perceived (self-reported) health symptoms were also obtained. The mean levels of airborne constituents in the swine air condition were hydrogen sulfide (24 ppb), ammonia (817 ppb), total suspended particulates (0.0241 mg/m3), endotoxin (7.40 endotoxin units/m3), and odor (57 times above odor threshold). No statistical differences on objective measures of physical symptoms, mood, or attention resulted from the 1-hr exposure to swine emissions in the environmental chamber when compared with clean air for healthy human volunteers. However, subjects were 4.1 (p = 0.001) times more likely to report headaches, 6.1 (p = 0.004) times more likely to report eye irritation, and 7.8 (p = 0.014) times more likely to report nausea in the swine air (experimental) condition than in the control condition. These results indicate that short-term exposure in an environmental chamber to malodorous emissions from a swine house at levels expected downwind can induce clinically important symptoms in healthy human volunteers.

Human mutagens: evidence from paternal exposure

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

Narod, S.A.; Douglas, G.R.; Nestmann, E.R.

1988-01-01

The importance of inherited mutations as a cause of human disease has been established clearly through examples of well-defined genetic anomalies, such as Down syndrome and retinoblastoma. Furthermore, it is suspected that environmental contaminants induce mutations resulting in increased risk for such defects in subsequent generations of persons exposed. The present lack of direct evidence for induced inherited genetic disorders in human beings hampers the development of risk estimation techniques for extrapolation from animal models. The most extensive prospective epidemiologic studies of inherited genetic effects have involved survivors of atomic bomb detonations and patients treated with cancer chemotherapy. In neithermore » case has a significant elevation in inherited genetic effects or cancer been detected in the offspring of exposed individuals. Epidemiologic studies of subjects receiving chronic exposure may be confounded by the effect of maternal exposure during pregnancy. Consideration of only paternal exposure can minimize the confounding influence of teratogenicity, enhancing the resolving power of studies for inherited effects. Using this approach, retrospective (case-control) studies of childhood cancer patients have provided limited but suggestive evidence for inheritance of induced effects. Endpoints, such as congenital malformations and spontaneous abortion following paternal exposure, can also be considered as indicators of heritable mutagenic effects. For example, there is limited evidence suggesting that paternal exposure to anaesthetic gases may cause miscarriage and congenital abnormalities as a result of induced male germ cell mutations. 104 references.« less

Formaldehyde Concentration Dynamics of the International Space Station Cabin Atmosphere

NASA Technical Reports Server (NTRS)

Perry, J. L.

2005-01-01

Formaldehyde presents a significant challenge to maintaining cabin air quality on board crewed spacecraft. Generation sources include offgassing from a variety of non-metallic materials as well as human metabolism. Because generation sources are pervasive and human health can be affected by continual exposure to low concentrations, toxicology and air quality control engineering experts jointly identified formaldehyde as a key compound to be monitored as part the International Space Station's (ISS) environmental health monitoring and maintenance program. Data acquired from in-flight air quality monitoring methods are the basis for assessing the cabin environment's suitability for long-term habitation and monitoring the performance of passive and active controls that are in place to minimize crew exposure. Formaldehyde concentration trends and dynamics served in the ISS cabin atmosphere are reviewed implications to present and future flight operations discussed.

Assessment of secondary sources of Persistent Organic Pollutants in the Arctic

NASA Astrophysics Data System (ADS)

Pisso, Ignacio; Eckhardt, Sabine; Breivik, Knut

2014-05-01

Persistent organic pollutants (POPs) including highly toxic pesticides and other chemicals accumulate in living tissues and magnify in food chains. POPs are subject to long-range transport and hence represent a serious public health issue even in regions where their production is regulated. Rational control strategies require an understanding of the overall relationship between environmental emissions of contaminants and environmental / human exposure. In this study, we assess the relationships between environmental emissions and potential human exposure of organic contaminants with emphasis on long-range atmospheric transport. We investigate whether atmospheric levels of POPs measured at Zeppelin observatory in Svalbard since the early '90s are controlled by primary or secondary emissions. We present statistical indications that the measurements are affected by secondary ocean emissions and discuss the applicability of different inverse modeling approaches.

[Contribution of ISPESL (National Institute for Occupational Safety and Prevention) for protecting workers from exposure to avian influenza].

PubMed

D'Ovidio, M C; Vonesch, N; Signorini, S; Tomao, P; Sbardella, D; Iavicoli, S

2009-01-01

Influenza virus A/H5N1 occurs mainly in birds, in which is highly contagious and deadly, and does not usually infect people. Most of the cases occurred in humans resulted from people having direct or close contact with H5N1 infected poultry or contaminated surfaces. The circulation of influenza viruses in birds, humans and other hosts represents a public and animal health threat, with important economic consequences. Controlling avian influenza in poultry, in particular with biosecurity measures, is the primary method to reduce human risk from infection. Enhanced surveillance both in poultry and in wild birds proved effective for the early detection of the infection. Worldwide most countries developed strategic plans, guidelines and recommendations for effective disease prevention and control. Moreover documents were specifically prepared to keep specific categories of workers adequately informed on how to avoid or minimize exposure to the viruses. In accordance with the Italian Decree 626/94, recently amended by the Decree 81/08, regarding the protection of workers from risks related to exposure to biological agents at work, the Department of Occupational Medicine of ISPESL prepared one booklet directed to people working with poultry and, together with Corpo Nazionale Vigili del Fuoco, two booklets addressed to fire brigade who could be at various levels involved in outbreak disease control and eradication activities. In fact information and training are essential aspects of a global preventive and protective strategy.

A dose-controlled system for air-liquid interface cell exposure and application to zinc oxide nanoparticles

PubMed Central

2009-01-01

Background Engineered nanoparticles are becoming increasingly ubiquitous and their toxicological effects on human health, as well as on the ecosystem, have become a concern. Since initial contact with nanoparticles occurs at the epithelium in the lungs (or skin, or eyes), in vitro cell studies with nanoparticles require dose-controlled systems for delivery of nanoparticles to epithelial cells cultured at the air-liquid interface. Results A novel air-liquid interface cell exposure system (ALICE) for nanoparticles in liquids is presented and validated. The ALICE generates a dense cloud of droplets with a vibrating membrane nebulizer and utilizes combined cloud settling and single particle sedimentation for fast (~10 min; entire exposure), repeatable (<12%), low-stress and efficient delivery of nanoparticles, or dissolved substances, to cells cultured at the air-liquid interface. Validation with various types of nanoparticles (Au, ZnO and carbon black nanoparticles) and solutes (such as NaCl) showed that the ALICE provided spatially uniform deposition (<1.6% variability) and had no adverse effect on the viability of a widely used alveolar human epithelial-like cell line (A549). The cell deposited dose can be controlled with a quartz crystal microbalance (QCM) over a dynamic range of at least 0.02-200 μg/cm2. The cell-specific deposition efficiency is currently limited to 0.072 (7.2% for two commercially available 6-er transwell plates), but a deposition efficiency of up to 0.57 (57%) is possible for better cell coverage of the exposure chamber. Dose-response measurements with ZnO nanoparticles (0.3-8.5 μg/cm2) showed significant differences in mRNA expression of pro-inflammatory (IL-8) and oxidative stress (HO-1) markers when comparing submerged and air-liquid interface exposures. Both exposure methods showed no cellular response below 1 μg/cm2 ZnO, which indicates that ZnO nanoparticles are not toxic at occupationally allowed exposure levels. Conclusion The ALICE is a useful tool for dose-controlled nanoparticle (or solute) exposure of cells at the air-liquid interface. Significant differences between cellular response after ZnO nanoparticle exposure under submerged and air-liquid interface conditions suggest that pharmaceutical and toxicological studies with inhaled (nano-)particles should be performed under the more realistic air-liquid interface, rather than submerged cell conditions. PMID:20015351

Transgenerational Effects of Prenatal Bisphenol A on Social Recognition

PubMed Central

Wolstenholme, Jennifer T.; Goldsby, Jessica A.; Rissman, Emilie F.

2014-01-01

Bisphenol A (BPA) is a man-made endocrine disrupting compound used to manufacture polycarbonate plastics. It is found in plastic bottles, canned food linings, thermal receipts and other commonly used items. Over 93% of people have detectable BPA levels in their urine. Epidemiological studies report correlations between BPA levels during pregnancy and activity, anxiety, and depression in children. We fed female mice control or BPA–containing diets that produced plasma BPA concentrations similar to concentrations in humans. Females were mated and at birth, pups were fostered to control dams to limit BPA exposure to gestation in the first generation. Sibling pairs were bred to the third generation with no further BPA exposure. First (F1) and third (F3) generation juveniles were tested for social recognition and in the open field. Adult F3 mice were tested for olfactory discrimination. In both generations, BPA exposed juvenile mice displayed higher levels of investigation than controls in a social recognition task. In F3 BPA exposed mice, dishabituation to a novel female was impaired. In the open field, no differences were noted in F1 mice, while in F3, BPA lineage mice were more active than controls. No impairments were detected in F3 mice, all were able to discriminate different male urine pools and urine from water. No sex differences were found in any task. These results demonstrate that BPA exposure during gestation has long lasting, transgenerational effects on social recognition and activity in mice. These findings show that BPA exposure has transgenerational actions on behavior and have implications for human neurodevelopmental behavioral disorders. PMID:24100195

Transgenerational effects of prenatal bisphenol A on social recognition.

PubMed

Wolstenholme, Jennifer T; Goldsby, Jessica A; Rissman, Emilie F

2013-11-01

Bisphenol A (BPA) is a man-made endocrine disrupting compound used to manufacture polycarbonate plastics. It is found in plastic bottles, canned food linings, thermal receipts and other commonly used items. Over 93% of people have detectable BPA levels in their urine. Epidemiological studies report correlations between BPA levels during pregnancy and activity, anxiety, and depression in children. We fed female mice control or BPA-containing diets that produced plasma BPA concentrations similar to concentrations in humans. Females were mated and at birth, pups were fostered to control dams to limit BPA exposure to gestation in the first generation. Sibling pairs were bred to the third generation with no further BPA exposure. First (F1) and third (F3) generation juveniles were tested for social recognition and in the open field. Adult F3 mice were tested for olfactory discrimination. In both generations, BPA exposed juvenile mice displayed higher levels of investigation than controls in a social recognition task. In F3 BPA exposed mice, dishabituation to a novel female was impaired. In the open field, no differences were noted in F1 mice, while in F3, BPA lineage mice were more active than controls. No impairments were detected in F3 mice, all were able to discriminate different male urine pools and urine from water. No sex differences were found in any task. These results demonstrate that BPA exposure during gestation has long lasting, transgenerational effects on social recognition and activity in mice. These findings show that BPA exposure has transgenerational actions on behavior and have implications for human neurodevelopmental behavioral disorders. © 2013.

Neuromotor effects of acute ethanol inhalation exposure in humans: a preliminary study.

PubMed

Nadeau, Véronique; Lamoureux, Daniel; Beuter, Anne; Charbonneau, Michel; Tardif, Robert

2003-07-01

Ethanol (ETOH) is added to unleaded gasoline to decrease environmental levels of carbon monoxide from automobiles emissions. Therefore, addition of ETOH in reformulated fuel will most likely increase and the involuntarily human exposure to this chemical will also increase. This preliminary study was undertaken to evaluate the possible neuromotor effects resulting from acute ETOH exposure by inhalation in humans. Five healthy non-smoking adult males, with no history of alcohol abuse, were exposed by inhalation, in a dynamic, controlled-environment exposure chamber, to various concentrations of ETOH (0, 250, 500 and 1,000 ppm in air) for six hours. Reaction time, body sway, hand tremor and rapid alternating movements were measured before and after each exposure session by using the CATSYS 7.0 system and a diadochokinesimeter. The concentrations of ETOH in blood and in alveolar air were also measured. ETOH was not detected in blood nor in alveolar air when volunteers were exposed to 250 and 500 ppm, but at the end of exposure to 1,000 ppm, blood and alveolar air concentrations were 0.443 mg/100ml and 253.1 ppm, respectively. The neuromotor tests did not show conclusively significant differences between the exposed and non-exposed conditions. In conclusion, this study suggests that acute exposure to ethanol at 1,000 ppm or lower or to concentrations that could be encountered upon refueling is not likely to cause any significant neuromotor alterations in healthy males.

Geographic variation in risk factors for SFG rickettsial and leptospiral exposure in Colombia.

PubMed

Padmanabha, Harish; Hidalgo, Marylin; Valbuena, Gustavo; Castaneda, Elizabeth; Galeano, Armando; Puerta, Henry; Cantillo, Cesar; Mantilla, Gilma

2009-10-01

In order to characterize the patterns of human exposure to spotted fever group (SFG) rickettsial and leptospiral infection, IgG surveys were conducted on 642 residents of ten different areas of the rural district of Necoclí, Colombia. Areas were selected based on forest cover and human settlement pattern, and individual risk factors were elucidated through multivariate logistic models, controlling for variance clustering within communities. Overall, prevalence of high antibody titers indicating previous exposure to SFG rickettsia and leptospira was 29.2% and 35.6%, respectively, and both were most prevalent in the same peri-urban neighborhood. Forest cover .10% demonstrated the strongest independent association with leptospiral exposure, followed by homes with outdoor storage sheds. Isolated rural housing was the only variable independently associated with SFG rickettsia exposure. Community-level variables significantly modified the effects of individual risk factors. For both pathogens the eldest quartile was less exposed in periurban areas although there was no age effect overall for either. Females living in population settlements were more exposed to SFG rickettsiae but there was no sex association in isolated rural houses. Similarly, in sites with forest cover .10%, individuals working at home had higher leptospira seroprevalence, but place of work was not a risk factor in areas of forest cover ,10%. These data suggest that the patterns of maintenance and/or exposure to leptospira and rickettsia vary across different human created landscapes and settlement patterns. While contrasting risk factors may reflect the unique transmission cycles of each pathogen, the observed patterns of geographic variation suggest that both diseases may respond similarly larger scale human-ecological dynamics.

Micro RNA responses to chronic or acute exposures to low dose ionizing radiation

PubMed Central

Chaudhry, M. Ahmad; Omaruddin, Romaica A.; Kreger, Bridget; de Toledo, Sonia M.; Azzam, Edouard I.

2014-01-01

Human health risks of exposure to low dose ionizing radiation remain ambiguous and are the subject of intense debate. A wide variety of biological effects are induced after cellular exposure to ionizing radiation, but the underlying molecular mechanism(s) remain to be completely understood. We hypothesized that low dose c-radiation-induced effects are controlled by the modulation of micro RNA (miRNA) that participate in the control of gene expression at the posttranscriptional level and are involved in many cellular processes. We monitored the expression of several miRNA in human cells exposed to acute or chronic low doses of 10 cGy or a moderate dose of 400 cGy of 137Cs γ-rays. Dose, dose rate and time dependent differences in the relative expression of several miRNA were investigated. The expression patterns of many miRNA differed after exposure to either chronic or acute 10 cGy. The expression of miRNA let-7e, a negative regulator of RAS oncogene, and the c-MYC miRNA cluster were upregulated after 10 cGy chronic dose but were downregulated after 3 h of acute 10 cGy. The miR-21 was upregulated in chronic or acute low dose and moderate dose treated cells and its target genes hPDCD4, hPTEN, hSPRY2, and hTPM1 were found to be downregulated. These findings provide evidence that low dose and dose rate c-irradiation dictate the modulation of miRNA, which can result in a differential cellular response than occurs at high doses. This information will contribute to understanding the risks to human health after exposure to low dose radiation. PMID:22367372

Aluminum Exposure at Human Dietary Levels for 60 Days Reaches a Threshold Sufficient to Promote Memory Impairment in Rats.

PubMed

Martinez, Caroline S; Alterman, Caroline D C; Peçanha, Franck M; Vassallo, Dalton V; Mello-Carpes, Pâmela B; Miguel, Marta; Wiggers, Giulia A

2017-01-01

Aluminum (Al) is a significant environmental contaminant. While a good deal of research has been conducted on the acute neurotoxic effects of Al, little is known about the effects of longer-term exposure at human dietary Al levels. Therefore, the purpose of this study was to investigate the effects of 60-day Al exposure at low doses for comparison with a model of exposure known to produce neurotoxicity in rats. Three-month-old male Wistar rats were divided into two major groups: (1) low aluminum levels, and (2) a high aluminum level. Group 1 rats were treated orally by drinking water for 60 days as follows: (a) control-received ultrapure drinking water; (b) aluminum at 1.5 mg/kg b.w., and (c) aluminum at 8.3 mg/kg b.w. Group 2 rats were treated through oral gavages for 42 days as follows: (a) control-received ultrapure water; (b) aluminum at 100 mg/kg b.w. We analyzed cognitive parameters, biomarkers of oxidative stress and acetylcholinesterase (AChE) activity in hippocampus and prefrontal cortex. Al treatment even at low doses promoted recognition memory impairment seen in object recognition memory testing. Moreover, Al increased hippocampal reactive oxygen species and lipid peroxidation, reduced antioxidant capacity, and decreased AChE activity. Our data demonstrate that 60-day subchronic exposure to low doses of Al from feed and added to the water, which reflect human dietary Al intake, reaches a threshold sufficient to promote memory impairment and neurotoxicity. The elevation of oxidative stress and cholinergic dysfunction highlight pathways of toxic actions for this metal.

Digital music exposure reliably induces temporary threshold shift in normal-hearing human subjects.

PubMed

Le Prell, Colleen G; Dell, Shawna; Hensley, Brittany; Hall, James W; Campbell, Kathleen C M; Antonelli, Patrick J; Green, Glenn E; Miller, James M; Guire, Kenneth

2012-01-01

One of the challenges for evaluating new otoprotective agents for potential benefit in human populations is the availability of an established clinical paradigm with real-world relevance. These studies were explicitly designed to develop a real-world digital music exposure that reliably induces temporary threshold shift (TTS) in normal-hearing human subjects. Thirty-three subjects participated in studies that measured effects of digital music player use on hearing. Subjects selected either rock or pop music, which was then presented at 93 to 95 (n = 10), 98 to 100 (n = 11), or 100 to 102 (n = 12) dBA in-ear exposure level for a period of 4 hr. Audiograms and distortion product otoacoustic emissions (DPOAEs) were measured before and after music exposure. Postmusic tests were initiated 15 min, 1 hr 15 min, 2 hr 15 min, and 3 hr 15 min after the exposure ended. Additional tests were conducted the following day and 1 week later. Changes in thresholds after the lowest-level exposure were difficult to distinguish from test-retest variability; however, TTS was reliably detected after higher levels of sound exposure. Changes in audiometric thresholds had a "notch" configuration, with the largest changes observed at 4 kHz (mean = 6.3 ± 3.9 dB; range = 0-14 dB). Recovery was largely complete within the first 4 hr postexposure, and all subjects showed complete recovery of both thresholds and DPOAE measures when tested 1 week postexposure. These data provide insight into the variability of TTS induced by music-player use in a healthy, normal-hearing, young adult population, with music playlist, level, and duration carefully controlled. These data confirm the likelihood of temporary changes in auditory function after digital music-player use. Such data are essential for the development of a human clinical trial protocol that provides a highly powered design for evaluating novel therapeutics in human clinical trials. Care must be taken to fully inform potential subjects in future TTS studies, including protective agent evaluations, that some noise exposures have resulted in neural degeneration in animal models, even when both audiometric thresholds and DPOAE levels returned to pre-exposure values.

78 FR 77686 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-24

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Designation of a Class of Employees for Addition to the... Disease Control and Prevention, Department of Health and Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from the Rocky Flats Plant in Golden...

78 FR 64501 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-29

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Designation of a Class of Employees for Addition to the... Disease Control and Prevention, Department of Health and Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from the Pantex Plant in Amarillo...

78 FR 18351 - Determination Concerning a Petition To Add a Class of Employees to the Special Exposure Cohort

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Determination Concerning a Petition To Add a Class of... (NIOSH), Centers for Disease Control and Prevention, Department of Health and Human Services (HHS... monitored (urine or fecal), who worked at the Plutonium Finishing Plant in the 200 Area at the Hanford site...

77 FR 76489 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-28

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Designation of a Class of Employees for Addition to the... Disease Control and Prevention, Department of Health and Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from the Mound Plant in Miamisburg...

Inhibition of fried meat-induced rectal DNA damage and altered systemic genotoxicity in humans by crucifera, chlorophyllin, and yogurt

EPA Science Inventory

Dietary exposures implicated as reducing or causing risk for colorectal cancer may reduce or cause DNA damage in colon tissue; however, no one has assessed this hypothesis directly in humans. Thus, we enrolled 16 healthy volunteers in a 4-week controlled feeding study where 8 sub...

Visual Compensatory Tracking Performance after Exposure to Flashblinding Pulses. I. Comparison of Human and Rhesus Monkey Subjects

DTIC Science & Technology

1981-04-01

If different Irom Report) 18. SUPPLEMENTARY NOTES 19. KEY WOROS rContlnuo nrn rever.se ., vde it nee.ssary and rdenrlfy hv brock number) Flashbl...control strategy plays a minor or secondary role in predicting the effects of an insult to the system would be more acceptable. CONCLUSIONS Humans and

Worldwide Regulations of Standard Values of Pesticides for Human Health Risk Control: A Review.

PubMed

Li, Zijian; Jennings, Aaron

2017-07-22

Abstract : The impact of pesticide residues on human health is a worldwide problem, as human exposure to pesticides can occur through ingestion, inhalation, and dermal contact. Regulatory jurisdictions have promulgated the standard values for pesticides in residential soil, air, drinking water, and agricultural commodity for years. Until now, more than 19,400 pesticide soil regulatory guidance values (RGVs) and 5400 pesticide drinking water maximum concentration levels (MCLs) have been regulated by 54 and 102 nations, respectively. Over 90 nations have provided pesticide agricultural commodity maximum residue limits (MRLs) for at least one of the 12 most commonly consumed agricultural foods. A total of 22 pesticides have been regulated with more than 100 soil RGVs, and 25 pesticides have more than 100 drinking water MCLs. This research indicates that those RGVs and MCLs for an individual pesticide could vary over seven (DDT drinking water MCLs), eight (Lindane soil RGVs), or even nine (Dieldrin soil RGVs) orders of magnitude. Human health risk uncertainty bounds and the implied total exposure mass burden model were applied to analyze the most commonly regulated and used pesticides for human health risk control. For the top 27 commonly regulated pesticides in soil, there are at least 300 RGVs (8% of the total) that are above all of the computed upper bounds for human health risk uncertainty. For the top 29 most-commonly regulated pesticides in drinking water, at least 172 drinking water MCLs (5% of the total) exceed the computed upper bounds for human health risk uncertainty; while for the 14 most widely used pesticides, there are at least 310 computed implied dose limits (28.0% of the total) that are above the acceptable daily intake values. The results show that some worldwide standard values were not derived conservatively enough to avoid human health risk by the pesticides, and that some values were not computed comprehensively by considering all major human exposure pathways.

Worldwide Regulations of Standard Values of Pesticides for Human Health Risk Control: A Review

PubMed Central

Jennings, Aaron

2017-01-01

The impact of pesticide residues on human health is a worldwide problem, as human exposure to pesticides can occur through ingestion, inhalation, and dermal contact. Regulatory jurisdictions have promulgated the standard values for pesticides in residential soil, air, drinking water, and agricultural commodity for years. Until now, more than 19,400 pesticide soil regulatory guidance values (RGVs) and 5400 pesticide drinking water maximum concentration levels (MCLs) have been regulated by 54 and 102 nations, respectively. Over 90 nations have provided pesticide agricultural commodity maximum residue limits (MRLs) for at least one of the 12 most commonly consumed agricultural foods. A total of 22 pesticides have been regulated with more than 100 soil RGVs, and 25 pesticides have more than 100 drinking water MCLs. This research indicates that those RGVs and MCLs for an individual pesticide could vary over seven (DDT drinking water MCLs), eight (Lindane soil RGVs), or even nine (Dieldrin soil RGVs) orders of magnitude. Human health risk uncertainty bounds and the implied total exposure mass burden model were applied to analyze the most commonly regulated and used pesticides for human health risk control. For the top 27 commonly regulated pesticides in soil, there are at least 300 RGVs (8% of the total) that are above all of the computed upper bounds for human health risk uncertainty. For the top 29 most-commonly regulated pesticides in drinking water, at least 172 drinking water MCLs (5% of the total) exceed the computed upper bounds for human health risk uncertainty; while for the 14 most widely used pesticides, there are at least 310 computed implied dose limits (28.0% of the total) that are above the acceptable daily intake values. The results show that some worldwide standard values were not derived conservatively enough to avoid human health risk by the pesticides, and that some values were not computed comprehensively by considering all major human exposure pathways. PMID:28737697

Occupational exposure to diesel and gasoline emissions and lung cancer in Canadian men.

PubMed

Villeneuve, Paul J; Parent, Marie-Élise; Sahni, Vanita; Johnson, Kenneth C

2011-07-01

The International Agency for Research on Cancer classifies diesel exhaust as a probable human carcinogen; this decision is based largely from lung cancer evidence. Gasoline exhaust is classified as a possible carcinogen. Epidemiological studies are needed that improve upon some of the limitations of previous research with respect to the characterization of exposure, and the control for the potential confounding influence of smoking and other occupational exposures. Our objective was to investigate associations between occupational exposure to diesel and gasoline engine emissions and lung cancer. We used a case-control study design that involved men 40 years of age and older at the time of interview. Analyses are based on 1681 incident cases of lung cancer and 2,053 population controls. A self-reported questionnaire elicited a lifetime occupational history, including general tasks, and information on other potential risk factors. Occupational exposures to diesel and gasoline emissions, crystalline silica, and asbestos were assigned to each job held by study subjects by industrial hygienists who were blind to case-control status. Exposure metrics for diesel and gasoline emissions that were modeled included: ever exposure, cumulative exposure, and concentration of exposure. We found a dose-response relationship between cumulative occupational exposure to diesel engine emissions and lung cancer. This association was more pronounced for the squamous and large cell subtypes with adjusted odds ratios across the three increasing tertiles of cumulative lifetime exposure relative to those with no exposure of 0.99, 1.25, and 1.32 (p=0.04) for squamous cell carcinoma, and 1.06, 1.19, 1.68 (p=0.02) for large cell carcinoma. While the association with cumulative exposure to gasoline was weakly positive, it was not statistically significant. Our findings suggest that exposure to diesel engine emissions increases the risk of lung cancer particularly for squamous and large cell carcinoma subtypes. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

A critical review of epidemiologic studies of radiofrequency exposure and human cancers.

PubMed Central

Elwood, J M

1999-01-01

This paper reviews studies that have assessed associations between likely exposure to radiofrequency (RF) transmissions and various types of human cancer. These studies include three cluster investigations and five studies relating to general populations; all of these studies consider place of residence at the time of cancer diagnosis in regard to proximity to radio or television transmitters. There are also five relevant occupational cohort studies and several case-control studies of particular types of cancer. These studies assessed a large number of possible associations. Several positive associations suggesting an increased risk of some types of cancer in those who may have had greater exposure to RF emissions have been reported. However, the results are inconsistent: there is no type of cancer that has been consistently associated with RF exposures. The epidemiologic evidence falls short of the strength and consistency of evidence that is required to come to a reasonable conclusion that RF emissions are a likely cause of one or more types of human cancer. The evidence is weak in regard to its inconsistency, the design of the studies, the lack of detail on actual exposures, and the limitations of the studies in their ability to deal with other likely relevant factors. In some studies there may be biases in the data used PMID:10229715

Diesel engine exhaust and lung cancer: an unproven association.

PubMed Central

Muscat, J E; Wynder, E L

1995-01-01

The risk of lung cancer associated with diesel exhaust has been calculated from 14 case-control or cohort studies. We evaluated the findings from these studies to determine whether there is sufficient evidence to implicate diesel exhaust as a human lung carcinogen. Four studies found increased risks associated with long-term exposure, although two of the four studies were based on the same cohort of railroad workers. Six studies were inconclusive due to missing information on smoking habits, internal inconsistencies, or inadequate characterization of diesel exposure. Four studies found no statistically significant associations. It can be concluded that short-term exposure to diesel engine exhaust (< 20 years) does not have a causative role in human lung cancer. There is statistical but not causal evidence that long-term exposure to diesel exhaust (> 20 years) increases the risk of lung cancer for locomotive engineers, brakemen, and diesel engine mechanics. There is inconsistent evidence on the effects of long-term exposure to diesel exhaust in the trucking industry. There is no evidence for a joint effect of diesel exhaust and cigarette smoking on lung cancer risk. Using common criteria for determining causal associations, the epidemiologic evidence is insufficient to establish diesel engine exhaust as a human lung carcinogen. Images p812-a PMID:7498093

The Plasticizer Bisphenol A Perturbs the Hepatic Epigenome: A Systems Level Analysis of the miRNome

PubMed Central

Renaud, Ludivine; da Silveira, Willian A.; Hazard, E. Starr; Simpson, Jonathan; Falcinelli, Silvia; Carnevali, Oliana; Hardiman, Gary

2017-01-01

Ubiquitous exposure to bisphenol A (BPA), an endocrine disruptor (ED), has raised concerns for both human and ecosystem health. Epigenetic factors, including microRNAs (miRNAs), are key regulators of gene expression during cancer. The effect of BPA exposure on the zebrafish epigenome remains poorly characterized. Zebrafish represents an excellent model to study cancer as the organism develops a disease that resembles human cancer. Using zebrafish as a systems toxicology model, we hypothesized that chronic BPA-exposure impacts the miRNome in adult zebrafish and establishes an epigenome more susceptible to cancer development. After a 3 week exposure to 100 nM BPA, RNA from the liver was extracted to perform high throughput mRNA and miRNA sequencing. Differential expression (DE) analyses comparing BPA-exposed to control specimens were performed using established bioinformatics pipelines. In the BPA-exposed liver, 6188 mRNAs and 15 miRNAs were differently expressed (q ≤ 0.1). By analyzing human orthologs of the DE zebrafish genes, signatures associated with non-alcoholic fatty liver disease (NAFLD), oxidative phosphorylation, mitochondrial dysfunction and cell cycle were uncovered. Chronic exposure to BPA has a significant impact on the liver miRNome and transcriptome in adult zebrafish with the potential to cause adverse health outcomes including cancer. PMID:29027980

DEMONSTRATION OF HUMAN EXPOSURE TOOLS

EPA Science Inventory

The Human Exposure and Atmospheric Sciences Division (HEASD) of the National Exposure Research Laboratory (NERL) conducts research on exposure measurements, human activity patterns, exposure and dose models, and cumulative exposures critical for the Agency to make scientificall...

β-Endorphin enhances the phospholipase activity of the dandruff causing fungi Malassezia globosa and Malassezia restricta.

PubMed

Honnavar, Prasanna; Chakrabarti, Arunaloke; Prasad, Ghandam S; Singh, Pankaj; Dogra, Sunil; Rudramurthy, Shivaprakash M

2017-02-01

β-Endorphin is known to stimulate phospholipase production by Malassezia pachydermatis during canine dermatoses. The role of β-endorphin in Malassezia infection in humans is not well studied. The present study compares the influence of β-endorphin on Malassezia globosa and Malassezia restricta isolated from patients with seborrhoeic dermatitis/dandruff (SD/D) and healthy controls. Malassezia isolates (five each of the two species from patients and healthy controls) were grown on modified Dixon's agar with or without 100 nmol/L β-endorphin. Phospholipase activity was quantified based on its ability to hydrolyze L-α-phosphatidylcholine dimyristoyl (phospholipid substrate). Free fatty acid was measured by a colorimetry method. In isolates from patients, the phospholipase activity significantly increased after exposure to β-endorphin (M. globosa, P = .04; M. restricta, P = .001), which did not occur in isolates from healthy controls. Moreover, after β-endorphin exposure the patient isolates had significantly higher (P = .0004) phospholipase activity compared to the healthy control isolates. The results suggest that isolates of M. globosa and M. restricta from patients may differ from those of healthy humans. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of chronic lithium administration on renal acid excretion in humans and rats

PubMed Central

Weiner, I. David; Leader, John P.; Bedford, Jennifer J.; Verlander, Jill W.; Ellis, Gaye; Kalita, Priyakshi; Vos, Frederiek; de Jong, Sylvia; Walker, Robert J.

2014-01-01

Abstract Lithium therapy's most common side effects affecting the kidney are nephrogenic diabetes insipidus (NDI) and chronic kidney disease. Lithium may also induce a distal renal tubular acidosis. This study investigated the effect of chronic lithium exposure on renal acid–base homeostasis, with emphasis on ammonia and citrate excretion. We compared 11 individuals on long‐term lithium therapy with six healthy individuals. Under basal conditions, lithium‐treated individuals excreted significantly more urinary ammonia than did control subjects. Following an acute acid load, urinary ammonia excretion increased approximately twofold above basal rates in both lithium‐treated and control humans. There were no significant differences between lithium‐treated and control subjects in urinary pH or urinary citrate excretion. To elucidate possible mechanisms, rats were randomized to diets containing lithium or regular diet for 6 months. Similar to humans, basal ammonia excretion was significantly higher in lithium‐treated rats; in addition, urinary citrate excretion was also significantly greater. There were no differences in urinary pH. Expression of the critical ammonia transporter, Rhesus C Glycoprotein (Rhcg), was substantially greater in lithium‐treated rats than in control rats. We conclude that chronic lithium exposure increases renal ammonia excretion through mechanisms independent of urinary pH and likely to involve increased collecting duct ammonia secretion via the ammonia transporter, Rhcg. PMID:25501430

Helminth–host immunological interactions: prevention and control of immune-mediated diseases

PubMed Central

Elliott, David E.; Weinstock, Joel V.

2013-01-01

Exposure to commensal and pathogenic organisms strongly influences our immune system. Exposure to helminths was frequent before humans constructed their current highly hygienic environment. Today, in highly industrialized countries, contact between humans and helminths is rare. Congruent with the decline in helminth infections is an increase in the prevalence of autoimmune and inflammatory disease. It is possible that exclusion of helminths from the environment has permitted the emergence of immune-mediated disease. We review the protective effects of helminths on expression of inflammatory bowel disease, multiple sclerosis, and animal models of these and other inflammatory diseases. We also review the immune pathways altered by helminths that may afford protection from these illnesses. Helminth exposure tends to inhibit IFN-γ and IL-17 production, promote IL-4, IL-10, and TGF-β release, induce CD4+ T cell Foxp3 expression, and generate regulatory macrophages, dendritic cells, and B cells. Helminths enable protective pathways that may vary by specific species and disease model. Helminths or their products likely have therapeutic potential to control or prevent immune-mediated illness. PMID:22239614

Canine Rabies: A Looming Threat to Public Health

PubMed Central

Burgos-Cáceres, Sigfrido

2011-01-01

Simple Summary This review is guided by three questions: What is canine rabies? Why is it a looming threat to public health? Why should we care about canine rabies being a public health threat? It seeks to answer these questions and notes that canine rabies is viral zoonosis with dogs being the major vectors. The disease is a looming threat to public health because rabid dogs bite humans, resulting in thousands of deaths every year. We should care about this evolving situation because, in general, rabies is a neglected disease for which there are vaccines, preventive measures, post-exposure prophylaxis, and control protocols. Abstract Rabies is an acute, fatal viral disease that infects domestic and wild animals and is transmissible to humans. Worldwide, rabies kills over 55,000 people every year. The domestic dog plays a pivotal role in rabies transmission. Domestic dogs are not only part of our daily lives but also of our immediate surroundings, and this is reflected in the rise in pet dog ownership in developed and developing countries. This is important given that more frequent exposures and interactions at the animal-human interface increases the likelihood of contracting zoonotic diseases of companion animals. Despite existing vaccines and post-exposure prophylactic treatment, rabies remains a neglected disease that is poorly controlled throughout much of the developing world, particularly Africa and Asia, where most human rabies deaths occur. It is believed that with sustained international commitments, global elimination of rabies from domestic dog populations, the most dangerous vector to humans, is a realistic goal. PMID:26486619

Tinnitus with a normal audiogram: Relation to noise exposure but no evidence for cochlear synaptopathy.

PubMed

Guest, Hannah; Munro, Kevin J; Prendergast, Garreth; Howe, Simon; Plack, Christopher J

2017-02-01

In rodents, exposure to high-level noise can destroy synapses between inner hair cells and auditory nerve fibers, without causing hair cell loss or permanent threshold elevation. Such "cochlear synaptopathy" is associated with amplitude reductions in wave I of the auditory brainstem response (ABR) at moderate-to-high sound levels. Similar ABR results have been reported in humans with tinnitus and normal audiometric thresholds, leading to the suggestion that tinnitus in these cases might be a consequence of synaptopathy. However, the ABR is an indirect measure of synaptopathy and it is unclear whether the results in humans reflect the same mechanisms demonstrated in rodents. Measures of noise exposure were not obtained in the human studies, and high frequency audiometric loss may have impacted ABR amplitudes. To clarify the role of cochlear synaptopathy in tinnitus with a normal audiogram, we recorded ABRs, envelope following responses (EFRs), and noise exposure histories in young adults with tinnitus and matched controls. Tinnitus was associated with significantly greater lifetime noise exposure, despite close matching for age, sex, and audiometric thresholds up to 14 kHz. However, tinnitus was not associated with reduced ABR wave I amplitude, nor with significant effects on EFR measures of synaptopathy. These electrophysiological measures were also uncorrelated with lifetime noise exposure, providing no evidence of noise-induced synaptopathy in this cohort, despite a wide range of exposures. In young adults with normal audiograms, tinnitus may be related not to cochlear synaptopathy but to other effects of noise exposure. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Effects of radiofrequency radiation emitted by cellular telephones on the cognitive functions of humans.

PubMed

Eliyahu, Ilan; Luria, Roy; Hareuveny, Ronen; Margaliot, Menachem; Meiran, Nachshon; Shani, Gad

2006-02-01

The present study examined the effects of exposure to Electromagnetic Radiation emitted by a standard GSM phone at 890 MHz on human cognitive functions. This study attempted to establish a connection between the exposure of a specific area of the brain and the cognitive functions associated with that area. A total of 36 healthy right-handed male subjects performed four distinct cognitive tasks: spatial item recognition, verbal item recognition, and two spatial compatibility tasks. Tasks were chosen according to the brain side they are assumed to activate. All subjects performed the tasks under three exposure conditions: right side, left side, and sham exposure. The phones were controlled by a base station simulator and operated at their full power. We have recorded the reaction times (RTs) and accuracy of the responses. The experiments consisted of two sections, of 1 h each, with a 5 min break in between. The tasks and the exposure regimes were counterbalanced. The results indicated that the exposure of the left side of the brain slows down the left-hand response time, in the second-later-part of the experiment. This effect was apparent in three of the four tasks, and was highly significant in only one of the tests. The exposure intensity and its duration exceeded the common exposure of cellular phone users.

High-performance metabolic profiling of plasma from seven mammalian species for simultaneous environmental chemical surveillance and bioeffect monitoring.

PubMed

Park, Youngja H; Lee, Kichun; Soltow, Quinlyn A; Strobel, Frederick H; Brigham, Kenneth L; Parker, Richard E; Wilson, Mark E; Sutliff, Roy L; Mansfield, Keith G; Wachtman, Lynn M; Ziegler, Thomas R; Jones, Dean P

2012-05-16

High-performance metabolic profiling (HPMP) by Fourier-transform mass spectrometry coupled to liquid chromatography gives relative quantification of thousands of chemicals in biologic samples but has had little development for use in toxicology research. In principle, the approach could be useful to detect complex metabolic response patterns to toxicologic exposures and to detect unusual abundances or patterns of potentially toxic chemicals. As an initial study to develop these possible uses, we applied HPMP and bioinformatics analysis to plasma of humans, rhesus macaques, marmosets, pigs, sheep, rats and mice to determine: (1) whether more chemicals are detected in humans living in a less controlled environment than captive species and (2) whether a subset of plasma chemicals with similar inter-species and intra-species variation could be identified for use in comparative toxicology. Results show that the number of chemicals detected was similar in humans (3221) and other species (range 2537-3373). Metabolite patterns were most similar within species and separated samples according to family and order. A total of 1485 chemicals were common to all species; 37% of these matched chemicals in human metabolomic databases and included chemicals in 137 out of 146 human metabolic pathways. Probability-based modularity clustering separated 644 chemicals, including many endogenous metabolites, with inter-species variation similar to intra-species variation. The remaining chemicals had greater inter-species variation and included environmental chemicals as well as GSH and methionine. Together, the data suggest that HPMP provides a platform that can be useful within human populations and controlled animal studies to simultaneously evaluate environmental exposures and biological responses to such exposures. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

[Human reproduction and environmental risk factors].

PubMed

Petrelli, G; Mantovani, A; Menditto, A

1999-01-01

Environmental pollution is a great cause of concern, in particular, growing attention is being paid to the potential of many chemicals to affect the reproductive system in humans. The key role of prevention and control of reproductive hazards is recognized world-wide. Many chemicals have been shown to impair fertility and/or prenatal and perinatal development in experimental studies. However, a sufficient evidence of an effect on human reproduction is available for some compounds only. The use of biological markers may improve the assessment of exposure to chemicals, contribute to identify mechanisms of action and put into evidence early, reversible, biological effects. Valid biological markers are also needed in epidemiological studies: without reliable data on the level of current and past exposures it is difficult to establish a causal relationship between a pollutant and the occurrence of adverse health effects. A multidisciplinary approach to risk assessment is required. Priorities for interdisciplinary research on environmental chemicals and reproduction include the identification of susceptible population subgroups and risk assessment of exposure to multiple chemicals.

Toxicology of dimethyl and monomethyl derivatives of acetamide and formamide: a second update.

PubMed

Kennedy, Gerald L

2012-11-01

Dimethylacetamide (DMAC) and dimethylformamide (DMF) continue to be important, widely used solvents involved in a wide variety of industrial applications. As liquids with relatively low vapor pressures, contact with both the integumentary and respiratory systems is the main source of human exposure. Although airborne control levels for the workplace have been established and industrial hygiene practices to limit dermal contact have been put in place, use of these chemicals has been associated with occupational illness, mainly in Asia where new and expanded uses have led to overexposures. Thus an update of the basic toxicology data including tables indicating the dose/exposure response characteristics of both DMAC and DMF is currently important. Both chemicals are similar from a toxicology perspective. Human experience has generally shown the materials to be without adverse effect except under conditions where airborne and dermal controls were not properly applied. The use of urinary metabolite monitoring has successfully been employed to measure integrated dermal and inhalation worker exposure. The chemicals are not particularly toxic following acute exposure but high doses can produce damage to the liver, the organ which is first affected by these two chemicals. Repeated dose/exposure studies have characterized both the targets of toxicity and the doses required to produce changes by various routes of exposure. Higher doses of these materials can produce changes in developing systems, infrequently in experiments at doses in which the maternal animal is unaffected, thus care needs to be taken when exposures are to women of child-bearing age. The chemicals appear to be low in genetic activity and inhalation exposures have not shown the materials to produce tumors in rodents except with DMF in a situation in which aerosol formation was encountered. This presentation extends the two previous reviews and, like those, includes updated information on acetamide and formamide and their monomethyl derivatives as well as the commercially important DMAC and DMF. Since a large portion of the newer information deals with effects in humans and biomonitoring, these sections are presented at the start of this review.

Respiratory tract toxicity in rats exposed to Mexico City air.

PubMed

Moss, O R; Gross, E A; James, R A; Janszen, D B; Ross, P W; Roberts, K C; Howard, A M; Harkema, J R; Calderón-Garcidueñas, L; Morgan, K T

2001-03-01

The rat has been used extensively as a health sentinel, indicator, or monitor of environmental health hazards, but this model has not been directly validated against human exposures. Humans in Mexico City show upper respiratory tract lesions and evidence of pulmonary damage related to their environmental inhalation exposure. In this study, male and female F344 rats were exposed (23 hr/day) in Mexico City to local Mexico City air (MCA)* for up to seven weeks. Controls were maintained at the same location under filtered air. Prior to these exposures, several steps were taken. First, the nasal passages of normal male rats shipped from the United States and housed in Mexico City were examined for mycoplasma infection; no evidence of infection was found. In addition, a mobile exposure and monitoring system was assembled and, with an ozone (O3) exposure atmosphere, was tested along with supporting histopathology techniques and analysis of rat nasal and lung tissues. Last, the entire exposure model (equipment and animals) was transported to Mexico City and validated for a three-week period. During the seven-week study there were 18 one-hour intervals during which the average O3 concentration of MCA in the exposure chamber exceeded the US National Ambient Air Quality Standard (NAAQS) of 0.120 ppm 03 (hourly average, not to be exceeded more than once per year). This prolonged exposure of healthy F344 rats to MCA containing episodically low to moderate concentrations of 03 (as well as other urban air pollutants) did not induce inflammatory or epithelial lesions in the nasal airways or lung as measured by qualitative histologic techniques or quantitative morphometric techniques. These findings agree with those of previous controlled O3 inhalation studies, but they are in contrast to reports indicating that O3-polluted MCA causes significant nasal mucosal injury in adults and children living in southwestern Mexico City. Taken together, these findings may suggest that human airways are markedly more susceptible to the toxic effects of MCA than are the airways of the F344 rat.

Digital music exposure reliably induces temporary threshold shift (TTS) in normal hearing human subjects

PubMed Central

Le Prell, C. G.; Dell, S.; Hensley, B.; Hall, J. W.; Campbell, K. C. M.; Antonelli, P. J.; Green, G. E.; Miller, J. M.; Guire, K.

2012-01-01

Objectives One of the challenges for evaluating new otoprotective agents for potential benefit in human populations is availability of an established clinical paradigm with real world relevance. These studies were explicitly designed to develop a real-world digital music exposure that reliably induces temporary threshold shift (TTS) in normal hearing human subjects. Design Thirty-three subjects participated in studies that measured effects of digital music player use on hearing. Subjects selected either rock or pop music, which was then presented at 93–95 (n=10), 98–100 (n=11), or 100–102 (n=12) dBA in-ear exposure level for a period of four hours. Audiograms and distortion product otoacoustic emissions (DPOAEs) were measured prior to and after music exposure. Post-music tests were initiated 15 min, 1 hr 15 min, 2 hr 15 min, and 3 hr 15 min after the exposure ended. Additional tests were conducted the following day and one week later. Results Changes in thresholds after the lowest level exposure were difficult to distinguish from test-retest variability; however, TTS was reliably detected after higher levels of sound exposure. Changes in audiometric thresholds had a “notch” configuration, with the largest changes observed at 4 kHz (mean=6.3±3.9dB; range=0–13 dB). Recovery was largely complete within the first 4 hours post-exposure, and all subjects showed complete recovery of both thresholds and DPOAE measures when tested 1-week post-exposure. Conclusions These data provide insight into the variability of TTS induced by music player use in a healthy, normal-hearing, young adult population, with music playlist, level, and duration carefully controlled. These data confirm the likelihood of temporary changes in auditory function following digital music player use. Such data are essential for the development of a human clinical trial protocol that provides a highly powered design for evaluating novel therapeutics in human clinical trials. Care must be taken to fully inform potential subjects in future TTS studies, including protective agent evaluations, that some noise exposures have resulted in neural degeneration in animal models, even when both audiometric thresholds and DPOAE levels returned to pre-exposure values. PMID:22885407

Antibodies to VP1 of swine pasivirus in humans without evidence of transmission from a pig source.

PubMed

Arnold, Francoise; Hober, Didier; Chaussade, Hélène; Dumarest, Marine; Sané, Famara; Nowakowsjki, Mireille; Rigaud, Emma; Bellalou, Jacques; Desailloud, Rachel; Coursaget, Pierre; Eloit, Marc

2015-08-01

Swine pasivirus (SPaV1) is a recently described enteric virus close to human parechoviruses and highly prevalent in pigs. Antibodies to Escherichia coli-expressed VP1 of SpaV1 have been found in a majority of humans in China. The objectives were to estimate the antibody prevalence in a European country, to test if exposure to the virus was linked to pig products and if this exposure was a risk factor for the development of diabetes type 1. An ELISA test was developed and used to screen 842 healthy subjects with known exposure to pig products, 39 patients with diabetes type 1 and 20 controls. We identified a high seroprevalence (15.6%) reacting to VP1 of SPaV1 among healthy human subjects. Analysis of risk factors argues against cross-species transmission from pigs as the source of infection. Data also indicate that the presence of SPaV1 VP1-binding antibodies is not associated with diabetes type 1 in humans. Our results suggest that the seroreactivity frequently found in humans against SpaV1 is due to cross-reactivity with related antigen, perhaps a picornavirus, and that SpaV1 is not a zoonotic virus. Copyright © 2015 Elsevier B.V. All rights reserved.

Single and Combined Exposure to Zinc- and Copper-Containing Welding Fumes Lead to Asymptomatic Systemic Inflammation.

PubMed

Markert, Agnieszka; Baumann, Ralf; Gerhards, Benjamin; Gube, Monika; Kossack, Veronika; Kraus, Thomas; Brand, Peter

2016-02-01

Recently, it has been shown that exposure to welding fumes containing both zinc and copper leads to asymptomatic systemic inflammation in humans as shown by an increase of blood C-reactive protein. In the present study, it was investigated which metal is responsible for this effect. Fifteen healthy male subjects were exposed under controlled conditions to welding fumes containing either zinc, or copper, or copper and zinc. For each exposure blood C-reactive protein increased. Copper- and zinc-containing welding fumes are able to induce systemic inflammation.

Pick your poison: what's new in poison control for the preschooler.

PubMed

Glenn, Lauren

2015-01-01

Accidental childhood poisonings are a major public health concern despite many efforts to alleviate this problem. While the rate of pediatric fatalities due to poisonings have decreased over the last two decades, poison control centers around the US have collectively fielded over one million calls with regard to toxic exposures in the preschool age group. According to the American Association of Poison Control Centers nearly half of all human exposures reported last year involved children under six. By focusing poison prevention efforts on the preschooler, we can attempt to decrease morbidity and mortality in the most vulnerable age group affected. Although the subject is still prevalent, current discussion on this topic is limited. Newer literature discusses past initiatives such as child resistant packaging and sticker deterrent programs and addresses their efficacy. This article revisits older mechanisms of prevention as well as the science behind the human motivation to change one's own practice and behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

Could cryopreserved human semen samples be stored at -80°C?

PubMed

Vaz, Carlos R; Lamim, Tamara; Salvador, Rafael A; Batschauer, Anna P B; Amaral, Vera Lucia L; Til, David

2018-06-01

To evaluate storage time effects in cryopreserved human semen samples, kept in the freezer at a controlled temperature of -80°C, on sperm viability after thawing. We used 20 semen samples. Each sample was cryopreserved in 10 fingers, which were divided into five groups: one group was kept in cryogenic canisters throughout the experiment(control), and four groups were kept in a VIP Ultra Low MDF-U76V- PE freezer, with the temperature set at -80°C, for 24, 48, 72 and 96 hours, respectively. After the exposure time, the samples were stored in cryogenic canisters after being thawed. The analyzed parameters were: motility, vitality and mitochondrial activity. After thawing, we noticed decreased sperm motility, vitality and mitochondrial activity, when comparing the tested groups with the control group, as well as a progressive reduction in the analyzed parameters between the times evaluated. Cryopreservation of semen samples at -80°C is potentially harmful to sperm viability, causing damage when submitted to longer exposure times.

Genetic damage in human cells exposed to non-ionizing radiofrequency fields: a meta-analysis of the data from 88 publications (1990-2011).

PubMed

Vijayalaxmi; Prihoda, Thomas J

2012-12-12

Based on the 'limited' evidence suggesting an association between exposure to radiofrequency fields (RF) emitted from mobile phones and two types of brain cancer, glioma and acoustic neuroma, the International Agency for Research on Cancer has classified RF as 'possibly carcinogenic to humans' in group 2B. In view of this classification and the positive correlation between increased genetic damage and carcinogenesis, a meta-analysis was conducted to determine whether a significant increase in genetic damage in human cells exposed to RF provides a potential mechanism for its carcinogenic potential. The extent of genetic damage in human cells, assessed from various end-points, viz., single-/double-strand breaks in the DNA, incidence of chromosomal aberrations, micronuclei and sister chromatid exchanges, reported in a total of 88 peer-reviewed scientific publications during 1990-2011 was considered in the meta-analysis. Among the several variables in the experimental protocols used, the influence of five specific variables related to RF exposure characteristics was investigated: (i) frequency, (ii) specific absorption rate, (iii) exposure as continuous wave, pulsed wave and occupationally exposed/mobile phone users, (iv) duration of exposure, and (v) different cell types. The data indicated the following. (1) The magnitude of difference between RF-exposed and sham-/un-exposed controls was small with some exceptions. (2) In certain RF exposure conditions there was a statistically significant increase in genotoxicity assessed from some end-points: the effect was observed in studies with small sample size and was largely influenced by publication bias. Studies conducted within the generally recommended RF exposure guidelines showed a smaller effect. (3) The multiple regression analyses and heterogeneity goodness of fit data indicated that factors other than the above five variables as well as the quality of publications have contributed to the overall results. (4) More importantly, the mean indices for chromosomal aberrations, micronuclei and sister chromatid exchange end-points in RF-exposed and sham-/un-exposed controls were within the spontaneous levels reported in a large data-base. Thus, the classification of RF as possibly carcinogenic to humans in group 2B was not supported by genotoxicity-based mechanistic evidence. Copyright © 2012 Elsevier B.V. All rights reserved.

Rabies in South Asia: fighting for elimination.

PubMed

Chowdhury, Fazle-Rabbi; Basher, Ariful; Amin, Mohammad R; Hassan, Nazia; Patwary, Mohammad I

2015-01-01

South Asia is regarded as the hot spot for the tourist and travelers. Unfortunately, three big countries (India, Pakistan and Bangladesh) of this region belong to top five rabies endemic countries of the world. Around 55,000 people die of rabies every year globally and 45% of them belong to South and South East Asia. Countries are now working on the elimination of rabies by the year 2020. Elimination of animal rabies is the pivotal of controlling human rabies. Dog (primary source) registration, population control and mass vaccination are the different ways of eliminating animal rabies. Pre (for risk groups including travelers) and post-exposure vaccine is the core for controlling human rabies. Post-exposure vaccine consists of nerve tissue vaccine and tissue culture vaccine. Due to low antigenicity and post-vaccine neurological complications all countries of South Asia except Pakistan have phased out the production and use of nerve tissue vaccine. To reduce the cost intramuscular regimen is now largely replaced by intradermal regimen and equine rabies immunoglobulin will probably replace human immunoglobulin in future for category III animal bite. 'SAARC' took initiatives for rabies elimination through 'SAARC development fund' which would hopefully play a vital role in regional collaboration to make the region rabies free.

In utero exposure to low doses of environmental pollutants disrupts fetal ovarian development in sheep

PubMed Central

Fowler, Paul A.; Dorà, Natalie J.; McFerran, Helen; Amezaga, Maria R.; Miller, David W.; Lea, Richard G.; Cash, Phillip; McNeilly, Alan S.; Evans, Neil P.; Cotinot, Corinne; Sharpe, Richard M.; Rhind, Stewart M.

2008-01-01

Epidemiological studies of the impact of environmental chemicals on reproductive health demonstrate consequences of exposure but establishing causative links requires animal models using ‘real life’ in utero exposures. We aimed to determine whether prolonged, low-dose, exposure of pregnant sheep to a mixture of environmental chemicals affects fetal ovarian development. Exposure of treated ewes (n = 7) to pollutants was maximized by surface application of processed sewage sludge to pasture. Control ewes (n = 10) were reared on pasture treated with inorganic fertilizer. Ovaries and blood were collected from fetuses (n = 15 control and n = 8 treated) on Day 110 of gestation for investigation of fetal endocrinology, ovarian follicle/oocyte numbers and ovarian proteome. Treated fetuses were 14% lighter than controls but fetal ovary weights were unchanged. Prolactin (48% lower) was the only measured hormone significantly affected by treatment. Treatment reduced numbers of growth differentiation factor (GDF9) and induced myeloid leukaemia cell differentiation protein (MCL1) positive oocytes by 25–26% and increased pro-apoptotic BAX by 65% and 42% of protein spots in the treated ovarian proteome were differently expressed compared with controls. Nineteen spots were identified and included proteins involved in gene expression/transcription, protein synthesis, phosphorylation and receptor activity. Fetal exposure to environmental chemicals, via the mother, significantly perturbs fetal ovarian development. If such effects are replicated in humans, premature menopause could be an outcome. PMID:18436539

Potential Mechanisms for Cancer Resistance in Elephants and Comparative Cellular Response to DNA Damage in Humans

PubMed Central

Abegglen, Lisa M.; Caulin, Aleah F.; Chan, Ashley; Lee, Kristy; Robinson, Rosann; Campbell, Michael S.; Kiso, Wendy K.; Schmitt, Dennis L.; Waddell, Peter J; Bhaskara, Srividya; Jensen, Shane T.; Maley, Carlo C.; Schiffman, Joshua D.

2016-01-01

IMPORTANCE Evolutionary medicine may provide insights into human physiology and pathophysiology, including tumor biology. OBJECTIVE To identify mechanisms for cancer resistance in elephants and compare cellular response to DNA damage among elephants, healthy human controls, and cancer-prone patients with Li-Fraumeni syndrome (LFS). DESIGN, SETTING, AND PARTICIPANTS A comprehensive survey of necropsy data was performed across 36 mammalian species to validate cancer resistance in large and long-lived organisms, including elephants (n = 644). The African and Asian elephant genomes were analyzed for potential mechanisms of cancer resistance. Peripheral blood lymphocytes from elephants, healthy human controls, and patients with LFS were tested in vitro in the laboratory for DNA damage response. The study included African and Asian elephants (n = 8), patients with LFS (n = 10), and age-matched human controls (n = 11). Human samples were collected at the University of Utah between June 2014 and July 2015. EXPOSURES Ionizing radiation and doxorubicin. MAIN OUTCOMES AND MEASURES Cancer mortality across species was calculated and compared by body size and life span. The elephant genome was investigated for alterations in cancer-related genes. DNA repair and apoptosis were compared in elephant vs human peripheral blood lymphocytes. RESULTS Across mammals, cancer mortality did not increase with body size and/or maximum life span (eg, for rock hyrax, 1% [95%CI, 0%–5%]; African wild dog, 8%[95%CI, 0%–16%]; lion, 2%[95%CI, 0% –7%]). Despite their large body size and long life span, elephants remain cancer resistant, with an estimated cancer mortality of 4.81% (95%CI, 3.14%–6.49%), compared with humans, who have 11% to 25%cancer mortality. While humans have 1 copy (2 alleles) of TP53, African elephants have at least 20 copies (40 alleles), including 19 retrogenes (38 alleles) with evidence of transcriptional activity measured by reverse transcription polymerase chain reaction. In response to DNA damage, elephant lymphocytes underwent p53-mediated apoptosis at higher rates than human lymphocytes proportional to TP53 status (ionizing radiation exposure: patients with LFS, 2.71% [95%CI, 1.93%–3.48%] vs human controls, 7.17%[95%CI, 5.91%–8.44%] vs elephants, 14.64%[95%CI, 10.91%–18.37%]; P < .001; doxorubicin exposure: human controls, 8.10% [95%CI, 6.55%–9.66%] vs elephants, 24.77%[95%CI, 23.0%–26.53%]; P < .001). CONCLUSIONS AND RELEVANCE Compared with other mammalian species, elephants appeared to have a lower-than-expected rate of cancer, potentially related to multiple copies of TP53. Compared with human cells, elephant cells demonstrated increased apoptotic response following DNA damage. These findings, if replicated, could represent an evolutionary-based approach for understanding mechanisms related to cancer suppression. PMID:26447779

Prevalence of antibodies to swine influenza viruses in humans with occupational exposure to pigs, Thuringia, Germany, 2008-2009.

PubMed

Krumbholz, Andi; Lange, Jeannette; Dürrwald, Ralf; Hoyer, Heike; Bengsch, Stefan; Wutzler, Peter; Zell, Roland

2010-09-01

The Eurasian lineages of swine influenza viruses are different genetically from classical swine H1N1 influenza viruses and comprise avian-like H1N1 and human-like H1N2 and H3N2 subtypes. Although sporadic isolation of such viruses from human specimens has been reported, the prevalence of human infections is not known. In the present study, the seroprevalence against Eurasian swine influenza viruses was investigated. Sera were collected in Thuringia, Germany, from December 2007 to April 2009. The study group comprised 118 professionals with occupational exposure to pigs (50 pig slaughterers/meat inspectors, 46 pig farmers, 22 veterinarians caring for pig herds). The control group included 118 age- and gender-matched blood donors from Thuringia. As a result, 18 sera of the study group were identified with raised hemagglutination-inhibition titers against a panel of nine swine influenza viruses (three strains/ subtype). For 17/18 sera this finding was confirmed in the neutralization assay. For 11/18 sera the raise of titers was significant, that is, a fourfold increase of hemagglutination-inhibition titers was observed. No gender-specific bias of the high titer sera was observed. Twelve sera of the control group showed increased hemagglutination-inhibition titers against swine influenza viruses. Hemagglutination-inhibition titers of 2/12 control sera were raised fourfold but did not exhibit a significant increase of neutralization titers. All increased hemagglutination-inhibition titers of the control group may be explained by cross-reactivity with seasonal influenza virus strains, as all these sera also reacted with human strains.

Occupational asphalt is not associated with head and neck cancer.

PubMed

Fogleman, E V; Eliot, M; Michaud, D S; Nelson, H H; McClean, M D; Langevin, S M; Kelsey, K T

2015-10-01

Epidemiologic studies that evaluate the relationship between occupational asphalt exposure and head and neck cancer have had a limited ability to control for known risk factors such as smoking, alcohol and human papillomavirus (HPV). To better elucidate this relationship by including known risk factors in a large case-control study of head and neck squamous cell carcinoma (HNSCC) from the greater Boston area. We analysed the relationship between occupational asphalt exposure and HNSCC among men in the Greater Boston area of Massachusetts. Analyses were conducted using unconditional multivariable logistic regression, performed with adjustments for age, race, education, smoking, alcohol consumption and HPV serology. There were 753 cases and 913 controls. No associations between HNSCC and occupational asphalt exposure (neither among ever-exposed nor by occupational duration) were observed for exposures in any occupation or those restricted to the construction industry. We also observed no associations in subgroup analyses of never-smokers and ever-smokers. Adjusting for known risk factors further reduced the estimated effect of asphalt exposure on HNSCC risk. We found no evidence for an association between occupational asphalt exposure and HNSCC. The null findings from this well-controlled analysis could suggest that the risk estimates stemming from occupational cohort studies may be overestimated due to uncontrolled confounding and enhance the literature available for weighing cancer risk from occupational exposure to bitumen. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of prenatal exposure to diesel exhaust particles on postnatal development, behavior, genotoxicity and inflammation in mice

PubMed Central

Hougaard, Karin S; Jensen, Keld A; Nordly, Pernille; Taxvig, Camilla; Vogel, Ulla; Saber, Anne T; Wallin, Håkan

2008-01-01

Background Results from epidemiological studies indicate that particulate air pollution constitutes a hazard for human health. Recent studies suggest that diesel exhaust possesses endocrine activity and therefore may affect reproductive outcome. This study in mice aimed to investigate whether exposure to diesel exhaust particles (DEP; NIST 2975) would affect gestation, postnatal development, activity, learning and memory, and biomarkers of transplacental toxicity. Pregnant mice (C57BL/6; BomTac) were exposed to 19 mg/m3 DEP (~1·106 particles/cm3; mass median diameter ≅ 240 nm) on gestational days 9–19, for 1 h/day. Results Gestational parameters were similar in control and diesel groups. Shortly after birth, body weights of DEP offspring were slightly lower than in controls. This difference increased during lactation, so by weaning the DEP exposed offspring weighed significantly less than the control progeny. Only slight effects of exposure were observed on cognitive function in female DEP offspring and on biomarkers of exposure to particles or genotoxic substances. Conclusion In utero exposure to DEP decreased weight gain during lactation. Cognitive function and levels of biomarkers of exposure to particles or to genotoxic substances were generally similar in exposed and control offspring. The particle size and chemical composition of the DEP and differences in exposure methods (fresh, whole exhaust versus aged, resuspended DEP) may play a significant role on the biological effects observed in this compared to other studies. PMID:18331653

Use of sensitive methods for detection of DNA damage on human lymphocytes exposed to p,p'-DDT: Comet assay and new criteria for scoring micronucleus test.

PubMed

Gajski, Goran; Ravlic, Sanda; Capuder, Zeljka; Garaj-Vrhovac, Vera

2007-08-01

Wide distribution, stability and long persistence in the environment of dichlorodiphenyltrichloroethane (DDT), probably the best-known and most useful insecticide in the world, imposes the need for further examination of the effect of this chemical on human health and especially on the human genome. In this study, peripheral blood human lymphocytes from a healthy donor were exposed to 0.025 mg/L concentration of p,p'-DDT at different time periods (1, 2, 24 and 48 h). For the assessment of genotoxic effect, the new criteria for scoring micronucleus test and alkaline comet assay were used. Both methods showed that p,p'-DDT induces DNA damage in low concentration used in this research. Results of micronucleus test showed a statistically significant (p < 0.05) genotoxic effect of p,p'-DDT on human lymphocytes compared with corresponding control and a different exposure time. A comet assay also showed increased DNA damage caused in p,p'-DDT-exposed human lymphocytes than in corresponding control cells for the tail length. Results obtained by measuring the level of DNA migration and incidence of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) indicate the sensitivity of these tests and their application in detection of primary genome damage after long-term exposure to establish the effect of p,p'-DDT on human genome.

ASSOCIATION BETWEEN URINARY MUTAGENICITY AND RISK OF COLORECTAL ADENOMAS IN A CLINIC-BASED CASE-CONTROL STUDY

EPA Science Inventory

ASSOCIATION BETWEEN URINARY MUTAGENICITY AND RISK OF COLORECTAL ADENOMAS IN A CLINIC-BASED CASE-CONTROL STUDY

Humans are exposed to a variety of mutagens from diet, smoking, or occupation. To explore if exposure to mutagens was related to the risk of colorectal adenomas i...

30 CFR 250.1913 - What criteria for operating procedures must my SEMS program meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

... presented by, the chemicals used in the operations; (9) Precautions you will take to prevent the exposure of chemicals used in your operations to personnel and the environment. The precautions must include control... purchasing these raw materials; (11) Control of hazardous chemical inventory; and (12) Impacts to the human...

30 CFR 250.1913 - What criteria for operating procedures must my SEMS program meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

... presented by, the chemicals used in the operations; (9) Precautions you will take to prevent the exposure of chemicals used in your operations to personnel and the environment. The precautions must include control... purchasing these raw materials; (11) Control of hazardous chemical inventory; and (12) Impacts to the human...

30 CFR 250.1913 - What criteria for operating procedures must my SEMS program meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

... presented by, the chemicals used in the operations; (9) Precautions you will take to prevent the exposure of chemicals used in your operations to personnel and the environment. The precautions must include control... purchasing these raw materials; (11) Control of hazardous chemical inventory; and (12) Impacts to the human...

Semi-quantitative proteomics of mammalian cells upon short-term exposure to non-ionizing electromagnetic fields.

PubMed

Kuzniar, Arnold; Laffeber, Charlie; Eppink, Berina; Bezstarosti, Karel; Dekkers, Dick; Woelders, Henri; Zwamborn, A Peter M; Demmers, Jeroen; Lebbink, Joyce H G; Kanaar, Roland

2017-01-01

The potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated. However, how exposure to these EMFs may lead to biological changes underlying possible health effects is still unclear. To reveal EMF-induced molecular changes, unbiased experiments (without a priori focusing on specific biological processes) with sensitive readouts are required. We present the first proteome-wide semi-quantitative mass spectrometry analysis of human fibroblasts, osteosarcomas and mouse embryonic stem cells exposed to three types of non-ionizing EMFs (ELF 50 Hz, UMTS 2.1 GHz and WiFi 5.8 GHz). We performed controlled in vitro EMF exposures of metabolically labeled mammalian cells followed by reliable statistical analyses of differential protein- and pathway-level regulations using an array of established bioinformatics methods. Our results indicate that less than 1% of the quantitated human or mouse proteome responds to the EMFs by small changes in protein abundance. Further network-based analysis of the differentially regulated proteins did not detect significantly perturbed cellular processes or pathways in human and mouse cells in response to ELF, UMTS or WiFi exposure. In conclusion, our extensive bioinformatics analyses of semi-quantitative mass spectrometry data do not support the notion that the short-time exposures to non-ionizing EMFs have a consistent biologically significant bearing on mammalian cells in culture.

Semi-quantitative proteomics of mammalian cells upon short-term exposure to non-ionizing electromagnetic fields

PubMed Central

Laffeber, Charlie; Eppink, Berina; Bezstarosti, Karel; Dekkers, Dick; Woelders, Henri; Zwamborn, A. Peter M.; Demmers, Jeroen; Lebbink, Joyce H. G.; Kanaar, Roland

2017-01-01

The potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated. However, how exposure to these EMFs may lead to biological changes underlying possible health effects is still unclear. To reveal EMF-induced molecular changes, unbiased experiments (without a priori focusing on specific biological processes) with sensitive readouts are required. We present the first proteome-wide semi-quantitative mass spectrometry analysis of human fibroblasts, osteosarcomas and mouse embryonic stem cells exposed to three types of non-ionizing EMFs (ELF 50 Hz, UMTS 2.1 GHz and WiFi 5.8 GHz). We performed controlled in vitro EMF exposures of metabolically labeled mammalian cells followed by reliable statistical analyses of differential protein- and pathway-level regulations using an array of established bioinformatics methods. Our results indicate that less than 1% of the quantitated human or mouse proteome responds to the EMFs by small changes in protein abundance. Further network-based analysis of the differentially regulated proteins did not detect significantly perturbed cellular processes or pathways in human and mouse cells in response to ELF, UMTS or WiFi exposure. In conclusion, our extensive bioinformatics analyses of semi-quantitative mass spectrometry data do not support the notion that the short-time exposures to non-ionizing EMFs have a consistent biologically significant bearing on mammalian cells in culture. PMID:28234898

Long-term exposure to noise impairs cortical sound processing and attention control.

PubMed

Kujala, Teija; Shtyrov, Yury; Winkler, Istvan; Saher, Marieke; Tervaniemi, Mari; Sallinen, Mikael; Teder-Sälejärvi, Wolfgang; Alho, Kimmo; Reinikainen, Kalevi; Näätänen, Risto

2004-11-01

Long-term exposure to noise impairs human health, causing pathological changes in the inner ear as well as other anatomical and physiological deficits. Numerous individuals are daily exposed to excessive noise. However, there is a lack of systematic research on the effects of noise on cortical function. Here we report data showing that long-term exposure to noise has a persistent effect on central auditory processing and leads to concurrent behavioral deficits. We found that speech-sound discrimination was impaired in noise-exposed individuals, as indicated by behavioral responses and the mismatch negativity brain response. Furthermore, irrelevant sounds increased the distractibility of the noise-exposed subjects, which was shown by increased interference in task performance and aberrant brain responses. These results demonstrate that long-term exposure to noise has long-lasting detrimental effects on central auditory processing and attention control.

Predictive & Prognostic Controller for Wide Band Gap (Silicon Carbide) Power Conversion (Preprint)

DTIC Science & Technology

2006-11-01

that is required for them to achieve their full potential, or other elements that are different from the traditional practice of Power Conditioning...symptoms, medical clinicians rely strongly on family history, individual history, environmental conditions or exposures and lifestyle to ascertain the...the model and possibly related models of the particular converter design. The lifestyle , the stress and the exposure that is considered in human

Sun Protection; A risk management approach

NASA Astrophysics Data System (ADS)

Diffey, Brian

2017-10-01

Sun Protection differentiates itself from other texts by adopting a risk-management approach to determine whether, how, and in what circumstances, harm might be caused, and to explore the feasibility of various strategies in controlling exposure to solar UV radiation. This multi-disciplinary book covers topics from climatology through human exposure to sunlight, as well as biological and clinical effects of UV radiation to physical and chemical strategies for photoprotection.

Development and evaluation of a technique for in vivo monitoring of 60Co in human lungs

NASA Astrophysics Data System (ADS)

de Mello, J. Q.; Lucena, E. A.; Dantas, A. L. A.; Dantas, B. M.

2016-07-01

60Co is a fission product of 235U and represents a risk of internal exposure of workers in nuclear power plants, especially those involved in the maintenance of potentially contaminated parts and equipment. The control of 60Co intake by inhalation can be performed through in vivo monitoring. This work describes the evaluation of a technique through the minimum detectable activity and the corresponding minimum detectable effective doses, based on biokinetic and dosimetric models of 60Co in the human body. The results allow to state that the technique is suitable either for monitoring of occupational exposures or evaluation of accidental intake.

Aflatoxins in Iran: Nature, Hazards and Carcinogenicity

PubMed Central

Khoshpey, B; Farhud, DD; Zaini, F

2011-01-01

Many studies have shown that mycotoxin contamination of agricultural products is a challenge for individual’s health especially in developing countries. Improper production and storage of foods, prepare conditions for aflatoxin production in crops, especially rice, wheat, pistachio, walnut, almond, etc which are the main sources of foods for people. Feeding livestock by contaminated bread is another way of human exposure to mycotoxins, especially aflatoxin and because of expensive methods for detecting and analyzing aflatoxin in laboratory; it is not measured in foods. This manuscript is a review of some Iranian and nonIranian reports about aflatoxin, its exposure ways, its adverse effect on human health and nutrition, as well as methods for reducing its exposure. Based on studies on foods, aflatoxin exposure is high in Iran. Since livestock feeding by contaminated bread is one of the potential ways for milk contamination, we should control and reduce aflatoxin contamination by improving production process, storage condition and livestock feeding as soon as possible. Pistachio is one of the most important exporting products of Iran and to maintain Iran’s position in exporting of this product, specific regulations on lowering its contamination with aflatoxin should be considered seriously. Finally, effective controlling of all food and feedstuffs which are vulnerable to aflatoxin contamination is necessary to prevent its effects. PMID:23113099

Effects of six priority controlled phthalate esters with long-term low-dose integrated exposure on male reproductive toxicity in rats.

PubMed

Gao, Hai-Tao; Xu, Run; Cao, Wei-Xin; Qian, Liang-Liang; Wang, Min; Lu, Lingeng; Xu, Qian; Yu, Shu-Qin

2017-03-01

Human beings are inevitably exposed to ubiquitous phthalate esters (PEs) surroundings. The purposes of this study were to investigate the effects of long-term low-dose exposure to the mixture of six priority controlled phthalate esters (MIXPs): dimethyl phthalate (DMP), diethyl phthalate (DEP), di(n-butyl) phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethyhexyl) phthalate (DEHP) and di-n-octyl phthalate (DNOP), on male rat reproductive system and further to explore the underlying mechanisms of the reproductive toxicity. The male rats were orally exposed to either sodium carboxymethyl cellulose as controls or MIXPs at three different low-doses by gavage for 15 weeks. Testosterone and luteinizing hormone (LH) in serum were analyzed, and pathological examinations were performed for toxicity evaluation. Steroidogenic proteins (StAR, P450scc, CYP17A1 and 17β-HSD), cell cycle and apoptosis-related proteins (p53, Chk1, Cdc2, CDK6, Bcl-2 and Bax) were measured for mechanisms exploration. MIXPs with long-term low-dose exposure could cause male reproductive toxicity to the rats, including the decrease of both serum and testicular testosterone, and the constructional damage of testis. These effects were related to down-regulated steroidogenic proteins, arresting cell cycle progression and promoting apoptosis in rat testicular cells. The results indicate that MIXPs with long-term low-dose exposure may pose male reproductive toxicity in human. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of sublethal exposure to boric acid sugar bait on adult survival, host-seeking, bloodfeeding behavior, and reproduction of Stegomyia albopicta.

PubMed

Ali, Arshad; Xue, Rui-De; Barnard, Donald R

2006-09-01

Effects of sublethal exposure to 0.1% boric acid sugar bait on adult survival, host-seeking, bloodfeeding behavior, and reproduction of Stegomyia albopicta were studied in the laboratory. Survival of males as well as females was significantly reduced when exposed to the bait, compared to control adults. The host-seeking and bloodfeeding activities in the baited females decreased, but the mean duration of blood engorgement (probing to voluntary withdrawal of proboscis) was not significantly different between the baited and control females. The landing and biting rates (human forearm) were significantly reduced in the baited females compared to nonbaited controls. Fecundity and fertility (based on number of laid eggs per female and percentage egg hatch, respectively) in the baited females were significantly reduced, and ovarian development was retarded. Sublethal exposure to sugar-based boric acid bait has the potential to reduce adult populations of St. albopicta.

Molecular and epidemiological population-based integrative analysis of human and animal Mycobacterium bovis infections in a low-prevalence setting.

PubMed

Palacios, Juan José; Navarro, Yurena; Romero, Beatriz; Penedo, Ana; Menéndez González, Ángela; Pérez Hernández, M Dolores; Fernández-Verdugo, Ana; Copano, Francisca; Torreblanca, Aurora; Bouza, Emilio; Domínguez, Lucas; de Juan, Lucía; García-de-Viedma, Darío

2016-11-15

Human Mycobacterium bovis infections are considered to be due to reactivations, when involve elderly people, or to recent transmissions, when exposure is occupational. We determined the cause of M. bovis infections by genotyping M. bovis isolates in a population-based study integrating human and animal databases. Among the 1,586 tuberculosis (TB) cases in Asturias, Northern Spain (1,080,000 inhabitants), 1,567 corresponded to M. tuberculosis and 19 to M. bovis. The number of human isolates sharing genotype with cattle isolates was higher than expected (47%) for a setting with low prevalence of bovine TB and efficient control programs in cattle. The risk of exposure to infected animals was probable/possible in most of these matched cases (77.7%). Recent transmission was the likely explanation of most M. bovis infections in elderly people. A potential human-to-human transmission was found. Our study illustrates a model of collaboration between human and animal health professionals to provide a precise snapshot of the transmission of M. bovis in the human-animal interface. Copyright © 2016 Elsevier B.V. All rights reserved.

Human microvascular dysfunction and apoptotic injury induced by AL amyloidosis light chain proteins.

PubMed

Migrino, Raymond Q; Truran, Seth; Gutterman, David D; Franco, Daniel A; Bright, Megan; Schlundt, Brittany; Timmons, Mitchell; Motta, Angelica; Phillips, Shane A; Hari, Parameswaran

2011-12-01

Light chain amyloidosis (AL) involves overproduction of amyloidogenic light chain proteins (LC) leading to heart failure, yet the mechanisms underlying tissue toxicity remain unknown. We hypothesized that LC induces endothelial dysfunction in non-AL human microvasculature and apoptotic injury in human coronary artery endothelial cells (HCAECs). Adipose arterioles (n = 34, 50 ± 3 yr) and atrial coronary arterioles (n = 19, 68 ± 2 yr) from non-AL subjects were cannulated. Adipose arteriole dilator responses to acetylcholine/papaverine were measured at baseline and 1 h exposure to LC (20 μg/ml) from biopsy-proven AL subjects (57 ± 11 yr) without and with antioxidant cotreatment. Coronary arteriole dilation to bradykinin/papaverine was measured post-LC exposure. HCAECs were exposed to 1 or 24 h of LC. LC reduced dilation to acetylcholine (10(-4) M: 41.6 ± 7 vs. 85.8 ± 2.2% control, P < 0.001) and papaverine (81.4 ± 4.6 vs. 94.8 ± 1.3% control, P < 0.01) in adipose arterioles and to bradykinin (10(-6) M: 68.6 ± 6.2 vs. 90.9 ± 1.6% control, P < 0.001) but not papaverine in coronary arterioles. There was an increase in superoxide and peroxynitrite in arterioles treated with LC. Adipose arteriole dilation was restored by cotreatment with polyethylene glycol-superoxide dismutase and tetrahydrobiopterin but only partially restored by mitoquinone (mitochondria-targeted antioxidant) and gp91ds-tat (NADPH oxidase inhibitor). HCAECs exposed to LC showed reduced NO and increased superoxide, peroxynitrite, annexin-V, and propidium iodide compared with control. Brief exposure to physiological amounts of LC induced endothelial dysfunction in human adipose and coronary arterioles and increased apoptotic injury in coronary artery endothelial cells likely as a result of oxidative stress, reduced NO bioavailability, and peroxynitrite production. Microvascular dysfunction and injury is a novel mechanism underlying AL pathobiology and is a potential target for therapy.

Humanoid Flight Metabolic Simulator Project

NASA Technical Reports Server (NTRS)

Ross, Stuart

2015-01-01

NASA's Evolvable Mars Campaign (EMC) has identified several areas of technology that will require significant improvements in terms of performance, capacity, and efficiency, in order to make a manned mission to Mars possible. These include crew vehicle Environmental Control and Life Support System (ECLSS), EVA suit Portable Life Support System (PLSS) and Information Systems, autonomous environmental monitoring, radiation exposure monitoring and protection, and vehicle thermal control systems (TCS). (MADMACS) in a Suit can be configured to simulate human metabolism, consuming crew resources (oxygen) in the process. In addition to providing support for testing Life Support on unmanned flights, MADMACS will also support testing of suit thermal controls, and monitor radiation exposure, body zone temperatures, moisture, and loads.

The effect of electromagnetic radiation emitted by display screens on cell oxygen metabolism - in vitro studies.

PubMed

Lewicka, Małgorzata; Henrykowska, Gabriela A; Pacholski, Krzysztof; Śmigielski, Janusz; Rutkowski, Maciej; Dziedziczak-Buczyńska, Maria; Buczyński, Andrzej

2015-12-10

Research studies carried out for decades have not solved the problem of the effect of electromagnetic radiation of various frequency and strength on the human organism. Due to this fact, we decided to investigate the changes taking place in human blood platelets under the effect of electromagnetic radiation (EMR) emitted by LCD monitors. The changes of selected parameters of oxygen metabolism were measured, i.e. reactive oxygen species concentration, enzymatic activity of antioxidant defence proteins - superoxide dismutase (SOD-1) and catalase (CAT) - and malondialdehyde concentration (MDA). A suspension of human blood platelets was exposed to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity for 30 and 60 min. The level of changes of the selected parameters of oxidative stress was determined after the exposure and compared to the control samples (not exposed). The measurements revealed an increase of the concentration of reactive oxygen species. The largest increase of ROS concentration vs. the control sample was observed after exposure to EMF of 220 V/m intensity for 60 min (from x = 54.64 to x = 72.92). The measurement of MDA concentration demonstrated a statistically significant increase after 30-min exposure to an EMF of 220 V/m intensity in relation to the initial values (from x = 3.18 to x = 4.41). The enzymatic activity of SOD-1 decreased after exposure (the most prominent change was observed after 60-min and 220 V/m intensity from x = 3556.41 to x = 1084.83). The most significant change in activity of catalase was observed after 60 min and 220 v/m exposure (from x = 6.28 to x = 4.15). The findings indicate that exposure to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity may cause adverse effects within blood platelets' oxygen metabolism and thus may lead to physiological dysfunction of the organism.

Epidemiologic studies of glyphosate and non-cancer health outcomes: a review.

PubMed

Mink, Pamela J; Mandel, Jack S; Lundin, Jessica I; Sceurman, Bonnielin K

2011-11-01

The United States (US) Environmental Protection Agency (EPA) and other regulatory agencies around the world have registered glyphosate as a broad-spectrum herbicide for use on multiple food and non-food use crops. To examine potential health risks in humans, we searched and reviewed the literature to evaluate whether exposure to glyphosate is associated causally with non-cancer health risks in humans. We also reviewed biomonitoring studies of glyphosate to allow for a more comprehensive discussion of issues related to exposure assessment and misclassification. Cohort, case-control and cross-sectional studies on glyphosate and non-cancer outcomes evaluated a variety of endpoints, including non-cancer respiratory conditions, diabetes, myocardial infarction, reproductive and developmental outcomes, rheumatoid arthritis, thyroid disease, and Parkinson's disease. Our review found no evidence of a consistent pattern of positive associations indicating a causal relationship between any disease and exposure to glyphosate. Most reported associations were weak and not significantly different from 1.0. Because accurate exposure measurement is crucial for valid results, it is recommended that pesticide-specific exposure algorithms be developed and validated. Copyright © 2011 Elsevier Inc. All rights reserved.

A Comparison of the Different Animal Models of Fetal Alcohol Spectrum Disorders and Their Use in Studying Complex Behaviors

PubMed Central

Patten, Anna R.; Fontaine, Christine J.; Christie, Brian R.

2014-01-01

Prenatal ethanol exposure (PNEE) has been linked to widespread impairments in brain structure and function. There are a number of animal models that are used to study the structural and functional deficits caused by PNEE, including, but not limited to invertebrates, fish, rodents, and non-human primates. Animal models enable a researcher to control important variables such as the route of ethanol administration, as well as the timing, frequency and amount of ethanol exposure. Each animal model and system of exposure has its place, depending on the research question being undertaken. In this review, we will examine the different routes of ethanol administration and the various animal models of fetal alcohol spectrum disorders (FASD) that are commonly used in research, emphasizing their strengths and limitations. We will also present an up-to-date summary on the effects of prenatal/neonatal ethanol exposure on behavior across the lifespan, focusing on learning and memory, olfaction, social, executive, and motor functions. Special emphasis will be placed where the various animal models best represent deficits observed in the human condition and offer a viable test bed to examine potential therapeutics for human beings with FASD. PMID:25232537

Inhibition of jet fuel aliphatic hydrocarbon induced toxicity in human epidermal keratinocytes.

PubMed

Inman, A O; Monteiro-Riviere, N A; Riviere, J E

2008-05-01

Jet propellant (JP)-8, the primary jet fuel used by the U.S. military, consists of hydrocarbon-rich kerosene base commercial jet fuel (Jet-A) plus additives DC1-4A, Stadis 450 and diethylene glycol monomethyl ether. Human epidermal keratinocytes (HEK) were exposed to JP-8, aliphatic hydrocarbon (HC) fuel S-8 and aliphatic HC pentadecane (penta), tetradecane (tetra), tridecane (tri) and undecane (un) for 5 min. Additional studies were conducted with signal transduction pathway blockers parthenolide (P; 3.0 microm), isohelenin (I; 3.0 microm), SB 203580 (SB; 13.3 microm), substance P (SP; 3.0 microm) and recombinant human IL-10 (rHIL-10; 10 ng ml(-1)). In the absence of inhibitors, JP-8 and to a lesser extent un and S-8, had the greatest toxic effect on cell viability and inflammation suggesting, as least in vitro, that synthetic S-8 fuel is less irritating than the currently used JP-8. Each inhibitor significantly (P < 0.05) decreased HEK viability. DMSO, the vehicle for P, I and SB, had a minimal effect on viability. Overall, IL-8 production was suppressed at least 30% after treatment with each inhibitor. Normalizing data relative to control indicate which inhibitors suppress HC-mediated IL-8 to control levels. P was the most effective inhibitor of IL-8 release; IL-8 was significantly decreased after exposure to un, tri, tetra and penta but significantly increased after JP-8 exposure compared with controls. Inhibitors were not effective in suppressing IL-8 release in JP-8 exposures to control levels. This study shows that inhibiting NF-kappa B, which appears to play a role in cytokine production in HC-exposed HEK in vitro, may reduce the inflammatory effect of HC in vivo. Copyright (c) 2007 John Wiley & Sons, Ltd.

CORRELATING NEUROBEHAVIORAL PERFORMANCE WITH BIOMARKERS OF ORGANOPHOSPHOROUS PESTICIDE EXPOSURE

PubMed Central

Rohlman, Diane S.; Anger, W Kent; Lein, Pamela J

2011-01-01

There is compelling evidence that adverse neurobehavioral effects are associated with occupational organophosphorous pesticide (OP) exposure in humans. Behavioral studies of pesticide applicators, greenhouse workers, agricultural workers and farm residents exposed repeatedly over months or years to low levels of OPs reveal a relatively consistent pattern of neurobehavioral deficits. However, only two studies have demonstrated a link between neurobehavioral performance and current biomarkers of OP exposure including blood cholinesterase (ChE) activity and urinary levels of OP metabolites. A variety of reasons may explain why so few studies have reported such correlations, including differing individual and group exposure histories, differing methodologies for assessing behavior and exposure, and lack of a reliable index of exposure. Alternatively, these data may suggest that current biomarkers (ChE, urine metabolites) are neither predictive nor diagnostic of the neurobehavioral effects of chronic OP pesticide exposures. This review focuses on the evidence that neurobehavioral performance deficits are associated with occupational OP pesticide exposure and concludes that research needs to return to the basics and rigorously test the relationships between neurobehavioral performance and both current (ChE and urine metabolites) and novel (eg, inflammation and oxidative stress) biomarkers using human and animal models. The results of such studies are critically important because OP pesticides are widely and extensively used throughout the world, including situations where exposure controls and personal protective equipment are not routinely used. PMID:21182866

In vitro evaluation of genotoxic effects under magnetic resonant coupling wireless power transfer.

PubMed

Mizuno, Kohei; Shinohara, Naoki; Miyakoshi, Junji

2015-04-07

Wireless power transfer (WPT) technology using the resonant coupling phenomenon has been widely studied, but there are very few studies concerning the possible relationship between WPT exposure and human health. In this study, we investigated whether exposure to magnetic resonant coupling WPT has genotoxic effects on WI38VA13 subcloned 2RA human fibroblast cells. WPT exposure was performed using a helical coil-based exposure system designed to transfer power with 85.4% efficiency at a 12.5-MHz resonant frequency. The magnetic field at the positions of the cell culture dishes is approximately twice the reference level for occupational exposure as stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The specific absorption rate at the positions of the cell culture dishes matches the respective reference levels stated in the ICNIRP guidelines. For assessment of genotoxicity, we studied cell growth, cell cycle distribution, DNA strand breaks using the comet assay, micronucleus formation, and hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation, and did not detect any significant effects between the WPT-exposed cells and control cells. Our results suggest that WPT exposure under the conditions of the ICNIRP guidelines does not cause detectable cellular genotoxicity.

Exploring consumer exposure pathways and patterns of use for chemicals in the environment.

PubMed

Dionisio, Kathie L; Frame, Alicia M; Goldsmith, Michael-Rock; Wambaugh, John F; Liddell, Alan; Cathey, Tommy; Smith, Doris; Vail, James; Ernstoff, Alexi S; Fantke, Peter; Jolliet, Olivier; Judson, Richard S

2015-01-01

Humans are exposed to thousands of chemicals in the workplace, home, and via air, water, food, and soil. A major challenge in estimating chemical exposures is to understand which chemicals are present in these media and microenvironments. Here we describe the Chemical/Product Categories Database (CPCat), a new, publically available (http://actor.epa.gov/cpcat) database of information on chemicals mapped to "use categories" describing the usage or function of the chemical. CPCat was created by combining multiple and diverse sources of data on consumer- and industrial-process based chemical uses from regulatory agencies, manufacturers, and retailers in various countries. The database uses a controlled vocabulary of 833 terms and a novel nomenclature to capture and streamline descriptors of chemical use for 43,596 chemicals from the various sources. Examples of potential applications of CPCat are provided, including identifying chemicals to which children may be exposed and to support prioritization of chemicals for toxicity screening. CPCat is expected to be a valuable resource for regulators, risk assessors, and exposure scientists to identify potential sources of human exposures and exposure pathways, particularly for use in high-throughput chemical exposure assessment.

Modulation of human alveolar macrophage properties by ozone exposure in vitro

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

Becker, S.; Madden, M.C.; Newman, S.L.

The study investigated changes in human alveolar macrophage (HAM) function after exposure in vitro to ozone (O3)(0.1-1.0 ppm for 2-4 hr). The functions studied reflect concern that O3 is detrimental to host defense mechanisms in the bronchoalveolar spaces. Exposure of HAM to O3 caused a concentration-dependent increase in release of prostaglandin E2(PGE2), an important modulator of inflammation, phagocytosis, and oxidative burst. Although phagocytosis of particulate immune complexes was decreased by O3, the authors found no change in the quantity of Fc receptors and complement receptors on the HAM surface. Superoxide (O2) production in response to phorbol ester was reduced aftermore » exposure of HAM to O3 while the basal O2 release in response to plastic adherence was not affected. Growth inhibition of the opportunistic yeast Cryptococcus neoformans by HAM was not affected by O3 exposure. The production of inflammatory mediators and immune modulators such as tumor necrosis factor-alpha, interleukin 1, and interleukin 6 were not induced by exposure to O3. However, compared to controls, O3-exposed HAM produced significantly lower levels of these cytokines when simulated with bacterial lipopolysaccharide (LPS).« less

Epidemiologic studies of glyphosate and cancer: a review.

PubMed

Mink, Pamela J; Mandel, Jack S; Sceurman, Bonnielin K; Lundin, Jessica I

2012-08-01

The United States Environmental Protection Agency and other regulatory agencies around the world have registered glyphosate as a broad-spectrum herbicide for use on multiple food and non-food use crops. Glyphosate is widely considered by regulatory authorities and scientific bodies to have no carcinogenic potential, based primarily on results of carcinogenicity studies of rats and mice. To examine potential cancer risks in humans, we reviewed the epidemiologic literature to evaluate whether exposure to glyphosate is associated causally with cancer risk in humans. We also reviewed relevant methodological and biomonitoring studies of glyphosate. Seven cohort studies and fourteen case-control studies examined the association between glyphosate and one or more cancer outcomes. Our review found no consistent pattern of positive associations indicating a causal relationship between total cancer (in adults or children) or any site-specific cancer and exposure to glyphosate. Data from biomonitoring studies underscore the importance of exposure assessment in epidemiologic studies, and indicate that studies should incorporate not only duration and frequency of pesticide use, but also type of pesticide formulation. Because generic exposure assessments likely lead to exposure misclassification, it is recommended that exposure algorithms be validated with biomonitoring data. Copyright © 2012 Elsevier Inc. All rights reserved.

Occupational exposure limits for nanomaterials: state of the art

NASA Astrophysics Data System (ADS)

Schulte, P. A.; Murashov, V.; Zumwalde, R.; Kuempel, E. D.; Geraci, C. L.

2010-08-01

Assessing the need for and effectiveness of controlling airborne exposures to engineered nanomaterials in the workplace is difficult in the absence of occupational exposure limits (OELs). At present, there are practically no OELs specific to nanomaterials that have been adopted or promulgated by authoritative standards and guidance organizations. The vast heterogeneity of nanomaterials limits the number of specific OELs that are likely to be developed in the near future, but OELs could be developed more expeditiously for nanomaterials by applying dose-response data generated from animal studies for specific nanoparticles across categories of nanomaterials with similar properties and modes of action. This article reviews the history, context, and approaches for developing OELs for particles in general and nanoparticles in particular. Examples of approaches for developing OELs for titanium dioxide and carbon nanotubes are presented and interim OELs from various organizations for some nanomaterials are discussed. When adequate dose-response data are available in animals or humans, quantitative risk assessment methods can provide estimates of adverse health risk of nanomaterials in workers and, in conjunction with workplace exposure and control data, provide a basis for determining appropriate exposure limits. In the absence of adequate quantitative data, qualitative approaches to hazard assessment, exposure control, and safe work practices are prudent measures to reduce hazards in workers.

HUMAN EXPOSURE ACTIVITY PATTERNS

EPA Science Inventory

Human activity/uptake rate data are necessary to estimate potential human exposure and intake dose to environmental pollutants and to refine human exposure models. Personal exposure monitoring studies have demonstrated the critical role that activities play in explaining and pre...

Prophylaxis of Human Hydrophobia in South Korea

PubMed Central

2014-01-01

Domestic human hydrophobia has not been reported since the one case of 2004 in South Korea, but still a few animal rabies occur persistently since the reemerging stage of rabies from 1993. The government has made efforts to control animal rabies in many aspects, but whether prophylactic strategy for human hydrophobia is performed adequately is in question. The rate of proper post-exposure prophylaxis for animal bite case in 'high-risk region' of rabies is very low with 20% between 2011 and 2013. The National Animal Bite Patient Surveillance targeting 'high-risk region' is missing out animal bite cases who visit directly to hospitals in 'suspect-risk region' of rabies. Little data seems to exist for pre-exposure prophylaxis of domestic hydrophobia. Danger of reoccurrence of human hydrophobia always remain in South Korea. The medical personnel needs to have greater interest on the matter and the government strengthen the management system. PMID:25298903

What is eating you? Stress and the drive to eat.

PubMed

Groesz, Lisa M; McCoy, Shannon; Carl, Jenna; Saslow, Laura; Stewart, Judith; Adler, Nancy; Laraia, Barbara; Epel, Elissa

2012-04-01

Non-human animal studies demonstrate relationships between stress and selective intake of palatable food. In humans, exposure to laboratory stressors and self-reported stress are associated with greater food intake. Large studies have yet to examine chronic stress exposure and eating behavior. The current study assessed the relationship between stress (perceived and chronic), drive to eat, and reported food frequency intake (nutritious food vs. palatable non-nutritious food) in women ranging from normal weight to obese (N=457). Greater reported stress, both exposure and perception, was associated with indices of greater drive to eat-including feelings of disinhibited eating, binge eating, hunger, and more ineffective attempts to control eating (rigid restraint; r's from .11 to .36, p's<.05). These data suggest that stress exposure may lead to a stronger drive to eat and may be one factor promoting excessive weight gain. Relationships between stress and eating behavior are of importance to public health given the concurrent increase in reported stress and obesity rates. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of Long-Term Dust Exposure on Human Respiratory System Health in Minqin County, China.

PubMed

Wang, Jinyu; Li, Sheng; Wang, Shigong; Shang, Kezheng

2015-01-01

The aim of this study was to assess the effects of long-term sand dust exposure on human respiratory health. Dust events break out frequently in Minqin County, northwest China, whereas Pingliang City, northwest China, is rarely influenced by dust events. Therefore, Minqin and Pingliang were selected as sand dust exposure region and control area, respectively. The incidence of respiratory system diseases and symptoms was determined through a structured respiratory health questionnaire (ATS-DLD-78-A) and personal interviews. The subjects comprised 728 farmers (Minqin, 424; Pingliang, 304) aged 40 years or older, who had nondocumented occupational history to industrial dust exposure. Prevalences (odds ratio [OR], 95% confidence interval [CI]) of chronic rhinitis, chronic bronchitis, and chronic cough increased 9.6% (3.141, 1.776-5.555), 7.5% (2.468, 1.421-4.286), and 10.2% (1.787, 1.246-2.563) in Minqin comparison with Pingliang, respectively, and the differences were significant (p <.01).

Radiation exposures due to fossil fuel combustion

NASA Astrophysics Data System (ADS)

Beck, Harold L.

The current consensus regarding the potential radiation exposures resulting from the combustion of fossil fuels is examined. Sources, releases and potential doses to humans are discussed, both for power plants and waste materials. It is concluded that the radiation exposure to most individuals from any pathway is probably insignificant, i.e. only a tiny fraction of the dose received from natural sources in soil and building materials. Any small dose that may result from power-plant emissions will most likely be from inhalation of the small insoluble ash particles from the more poorly controlled plants burning higher than average activity fuel, rather than from direct or indirect ingestion of food grown on contaminated soil. One potentially significant pathway for exposure to humans that requires further evaluation is the effect on indoor external γ-radiation levels resulting from the use of flyash in building materials. The combustion of natural gas in private dwellings is also discussed, and the radiological consequences are concluded to be generally insignificant, except under certain extraordinary circumstances.

Persistent effects of chronic Δ9-THC exposure on motor impulsivity in rats.

PubMed

Irimia, Cristina; Polis, Ilham Y; Stouffer, David; Parsons, Loren H

2015-08-01

In humans, long-term marijuana use is associated with impaired impulse control and attentional capacity, though it has been difficult to distinguish pre-existing cognitive deficits from possible consequences of prolonged marijuana exposure. To evaluate the effects of long-term exposure to Δ9-Tetrahydrocannabinol (Δ9-THC), the primary psychoactive constituent in marijuana, on indices of impulse control and attentional capacity using the rat 5-Choice Serial Reaction Time Task (5-CSRTT). Ten 14-day cycles of Δ9-THC dosing and 5-CSRTT testing were employed, each comprised of 5-day Δ9-THC dosing (0.3 or 3 mg/kg b.i.d.) and 5-CSRTT testing during the 9 days of drug abstinence. Subsequent 5-CSRTT testing continued during 5 weeks of protracted abstinence. Dose-dependent increases in motor impulsivity (premature responses) and behavioral disinhibition (perseverative responses) emerged following 5 cycles of Δ9-THC exposure that persisted for the remaining dosing and testing cycles. Δ9-THC-related disruptions in motor impulsivity and behavioral inhibition were most pronounced during cognitively challenging 5-CSRTT sessions incorporating varying novel inter-trial intervals (ITIs), and these disruptions persisted for at least 5 weeks of Δ9-THC abstinence. Δ9-THC-related impairments in attentional capacity (response accuracy) were also evident during variable ITI challenge tests, though these attentional disruptions abated within 3 weeks of Δ9-THC abstinence. These observations demonstrate that long-term intermittent exposure to clinically meaningful Δ9-THC doses induces persistent impairments in impulse control and attentional function. If present in humans, these disruptions may impact academic and professional performance.

Quantitative cancer risk assessment for occupational exposures to asphalt fumes during built-up roofing asphalt (BURA) operations.

PubMed

Rhomberg, Lorenz R; Mayfield, David B; Goodman, Julie E; Butler, Eric L; Nascarella, Marc A; Williams, Daniel R

2015-01-01

The International Agency for Research on Cancer qualitatively characterized occupational exposure to oxidized bitumen emissions during roofing as probably carcinogenic to humans (Group 2A). We examine chemistry, exposure, epidemiology and animal toxicity data to explore quantitative risks for roofing workers applying built-up roofing asphalt (BURA). Epidemiology studies do not consistently report elevated risks, and generally do not have sufficient exposure information or adequately control for confounders, precluding their use for dose-response analysis. Dermal carcinogenicity bioassays using mice report increased tumor incidence with single high doses. In order to quantify potential cancer risks, we develop time-to-tumor model methods [consistent with U.S. Environmental Protection Agency (EPA) dose-response analysis and mixtures guidelines] using the dose-time-response shape of concurrent exposures to benzo[a]pyrene (B[a]P) as concurrent controls (which had several exposure levels) to infer presumed parallel dose-time-response curves for BURA-fume condensate. We compare EPA relative potency factor approaches, based on observed relative potency of BURA to B[a]P in similar experiments, and direct observation of the inferred BURA dose-time-response (scaled to humans) as means for characterizing a dermal unit risk factor. We apply similar approaches to limited data on asphalt-fume inhalation and respiratory cancers in rats. We also develop a method for adjusting potency estimates for asphalts that vary in composition using measured fluorescence. Overall, the various methods indicate that cancer risks to roofers from both dermal and inhalation exposure to BURA are within a range typically deemed acceptable within regulatory frameworks. The approaches developed may be useful in assessing carcinogenic potency of other complex mixtures of polycyclic aromatic compounds.

Estrogens and development

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

McLachlan, J.A.; Newbold, R.R.

1987-11-01

The normal development of the genital organs of mammals, including humans, is under hormonal control. A role for the female sex hormone estrogen in this process is still unclear. However, exposure of experimental animals or humans to the potent exogenous estrogen, diethylstilbestrol (DES), results in persistent differentiation effects. Since many chemicals in the environment are weakly estrogenic, the possibility of hormonally altered differentiation must be considered.

DDT Exposure in Utero and Breast Cancer.

PubMed

Cohn, Barbara A; La Merrill, Michele; Krigbaum, Nickilou Y; Yeh, Gregory; Park, June-Soo; Zimmermann, Lauren; Cirillo, Piera M

2015-08-01

Currently no direct evidence links in utero dichlorodiphenyltrichloroethane (DDT) exposure to human breast cancer. However, in utero exposure to another xenoestrogen, diethylstilbestrol, predicts an increased breast cancer risk. If this finding extends to DDT, it could have far-reaching consequences. Many women were heavily exposed in utero during widespread DDT use in the 1960s. They are now reaching the age of heightened breast cancer risk. DDT exposure persists and use continues in Africa and Asia without clear knowledge of the consequences for the next generation. In utero exposure to DDT is associated with an increased risk of breast cancer. This was a case-control study nested in a prospective 54-year follow-up of 9300 daughters in the Child Health and Development Studies pregnancy cohort (n = 118 breast cancer cases, diagnosed by age 52 y and 354 controls matched on birth year). Kaiser Foundation Health Plan members who received obstetric care in Alameda County, California, from 1959 to 1967, and their adult daughters participated in the study. Daughters' breast cancer diagnosed by age 52 years as of 2012 was measured. Maternal o,p'-DDT predicted daughters' breast cancer (odds ratio fourth quartile vs first = 3.7, 95% confidence interval 1.5-9.0). Mothers' lipids, weight, race, age, and breast cancer history did not explain the findings. This prospective human study links measured DDT exposure in utero to risk of breast cancer. Experimental studies are essential to confirm results and discover causal mechanisms. Findings support classification of DDT as an endocrine disruptor, a predictor of breast cancer, and a marker of high risk.

Epidemiology of organophosphate pesticide poisoning in Taiwan.

PubMed

Lin, Tzeng Jih; Walter, Frank Gardner; Hung, Dong Zong; Tsai, Jin Lian; Hu, Sheng Chuan; Chang, Jung San; Deng, Jou-Fang; Chase, Jung San; Denninghoff, Kurt; Chan, Hon Man

2008-11-01

The nationwide epidemiology of organophosphate pesticide (OP) poisoning has never been reported in detail for Taiwan. This study retrospectively reviewed all human OP exposures reported to Taiwan's Poison Control Centers (PCCs) from July 1985 through December 2006. There were 4799 OP exposures. Most OP exposures were acute (98.37%) ingestions (74.50%) of a single OP (80.37%) to attempt suicide (64.72%) in adults (93.25%). Males were the most common gender (64.95%). Most patients (61.97%) received atropine and/or pralidoxime. The mortality rate for all 4799 OP exposures was 12.71%. Exposures to single OPs without co-intoxicants caused 524 deaths; of these, 63.36% were due to dimethyl OPs. Dimethyl OPs cause the majority of deaths in Taiwan.

Bird nesting and droppings control on highway structures.

DOT National Transportation Integrated Search

2010-10-01

This report provides a comprehensive literature survey of permanent and temporary deterrents to nesting and roosting, a : discussion of risks to human health and safety from exposure to bird nests and droppings and recommended protective measures, : ...

The impact of instrumental feeding on children's responses to taste exposure.

PubMed

Añez, E; Remington, A; Wardle, J; Cooke, L

2013-10-01

In a recent study, we showed that nonfood incentives combined with taste exposure increase children's acceptance of vegetables. However, the impact of children's previous experience of receiving food rewards is unknown. The present study investigated whether the experience of food rewards affects responses to an exposure-plus-reward intervention. One hundred and thirty-seven parents of 4-6-year-old children taking part in an exposure-based intervention study completed an instrumental feeding (IF) questionnaire aiming to assess their use of food rewards. Based on these scores, children were categorised as frequently or rarely instrumentally-fed. Intervention groups were given 12 daily tastes of a target vegetable combined with no reward, a tangible reward, (sticker) or a verbal reward (praise). A no-treatment control group received no tastings. Liking and intake of a target vegetable were measured at baseline and post-intervention. Irrespective of experience of IF, children in all intervention groups increased liking compared to controls (all P < 0.001) and both reward groups increased intake compared to controls (both P < 0.05). However, in the nonrewarded exposure group, only children with a limited experience with food rewards increased consumption (P < 0.05). Experience of IF may limit the benefits of 'mere exposure'. However, exposure with nonfood rewards can increase the acceptance of vegetables, regardless of previous experience. © 2012 The Authors Journal of Human Nutrition and Dietetics © 2012 The British Dietetic Association Ltd.

Classifying oxidative stress by F2-isoprostane levels across human diseases: A meta-analysis.

PubMed

van 't Erve, Thomas J; Kadiiska, Maria B; London, Stephanie J; Mason, Ronald P

2017-08-01

The notion that oxidative stress plays a role in virtually every human disease and environmental exposure has become ingrained in everyday knowledge. However, mounting evidence regarding the lack of specificity of biomarkers traditionally used as indicators of oxidative stress in human disease and exposures now necessitates re-evaluation. To prioritize these re-evaluations, published literature was comprehensively analyzed in a meta-analysis to quantitatively classify the levels of systemic oxidative damage across human disease and in response to environmental exposures. In this meta-analysis, the F 2 -isoprostane, 8-iso-PGF 2α , was specifically chosen as the representative marker of oxidative damage. To combine published values across measurement methods and specimens, the standardized mean differences (Hedges' g) in 8-iso-PGF 2α levels between affected and control populations were calculated. The meta-analysis resulted in a classification of oxidative damage levels as measured by 8-iso-PGF 2α across 50 human health outcomes and exposures from 242 distinct publications. Relatively small increases in 8-iso-PGF 2α levels (g<0.8) were found in the following conditions: hypertension (g=0.4), metabolic syndrome (g=0.5), asthma (g=0.4), and tobacco smoking (g=0.7). In contrast, large increases in 8-iso-PGF 2α levels were observed in pathologies of the kidney, e.g., chronic renal insufficiency (g=1.9), obstructive sleep apnoea (g=1.1), and pre-eclampsia (g=1.1), as well as respiratory tract disorders, e.g., cystic fibrosis (g=2.3). In conclusion, we have established a quantitative classification for the level of 8-iso-PGF 2α generation in different human pathologies and exposures based on a comprehensive meta-analysis of published data. This analysis provides knowledge on the true involvement of oxidative damage across human health outcomes as well as utilizes past research to prioritize those conditions requiring further scrutiny on the mechanisms of biomarker generation. Copyright © 2017. Published by Elsevier B.V.

Mental Health Functioning in the Human Rights Field: Findings from an International Internet-Based Survey.

PubMed

Joscelyne, Amy; Knuckey, Sarah; Satterthwaite, Margaret L; Bryant, Richard A; Li, Meng; Qian, Meng; Brown, Adam D

2015-01-01

Human rights advocates play a critical role in promoting respect for human rights world-wide, and engage in a broad range of strategies, including documentation of rights violations, monitoring, press work and report-writing, advocacy, and litigation. However, little is known about the impact of human rights work on the mental health of human rights advocates. This study examined the mental health profile of human rights advocates and risk factors associated with their psychological functioning. 346 individuals currently or previously working in the field of human rights completed an internet-based survey regarding trauma exposure, depression, posttraumatic stress disorder (PTSD), resilience and occupational burnout. PTSD was measured with the Posttraumatic Stress Disorder Checklist-Civilian Version (PCL-C) and depression was measured with the Patient History Questionnaire-9 (PHQ-9). These findings revealed that among human rights advocates that completed the survey, 19.4% met criteria for PTSD, 18.8% met criteria for subthreshold PTSD, and 14.7% met criteria for depression. Multiple linear regressions revealed that after controlling for symptoms of depression, PTSD symptom severity was predicted by human rights-related trauma exposure, perfectionism and negative self-appraisals about human rights work. In addition, after controlling for symptoms of PTSD, depressive symptoms were predicted by perfectionism and lower levels of self-efficacy. Survey responses also suggested high levels of resilience: 43% of responders reported minimal symptoms of PTSD. Although survey responses suggest that many human rights workers are resilient, they also suggest that human rights work is associated with elevated rates of PTSD and depression. The field of human rights would benefit from further empirical research, as well as additional education and training programs in the workplace about enhancing resilience in the context of human rights work.

Mental Health Functioning in the Human Rights Field: Findings from an International Internet-Based Survey

PubMed Central

Joscelyne, Amy; Knuckey, Sarah; Satterthwaite, Margaret L.; Bryant, Richard A.; Li, Meng; Qian, Meng; Brown, Adam D.

2015-01-01

Human rights advocates play a critical role in promoting respect for human rights world-wide, and engage in a broad range of strategies, including documentation of rights violations, monitoring, press work and report-writing, advocacy, and litigation. However, little is known about the impact of human rights work on the mental health of human rights advocates. This study examined the mental health profile of human rights advocates and risk factors associated with their psychological functioning. 346 individuals currently or previously working in the field of human rights completed an internet-based survey regarding trauma exposure, depression, posttraumatic stress disorder (PTSD), resilience and occupational burnout. PTSD was measured with the Posttraumatic Stress Disorder Checklist-Civilian Version (PCL-C) and depression was measured with the Patient History Questionnaire-9 (PHQ-9). These findings revealed that among human rights advocates that completed the survey, 19.4% met criteria for PTSD, 18.8% met criteria for subthreshold PTSD, and 14.7% met criteria for depression. Multiple linear regressions revealed that after controlling for symptoms of depression, PTSD symptom severity was predicted by human rights-related trauma exposure, perfectionism and negative self-appraisals about human rights work. In addition, after controlling for symptoms of PTSD, depressive symptoms were predicted by perfectionism and lower levels of self-efficacy. Survey responses also suggested high levels of resilience: 43% of responders reported minimal symptoms of PTSD. Although survey responses suggest that many human rights workers are resilient, they also suggest that human rights work is associated with elevated rates of PTSD and depression. The field of human rights would benefit from further empirical research, as well as additional education and training programs in the workplace about enhancing resilience in the context of human rights work. PMID:26700305

Alterations in cell migration and cell viability of wounded human skin fibroblasts following visible red light exposure

NASA Astrophysics Data System (ADS)

Prabhu, Vijendra; Rao, Bola Sadashiva S.; Mahato, Krishna Kishore

2014-02-01

The present study intended to examine the effect of visible red light on structural and cellular parameters on wounded skin fibroblast cells. To achieve the stated objective, uniform scratch was created on confluent monolayered human skin fibroblast cells, and were exposed to single dose of He-Ne laser (15 mm spot, 6.6808 mWcm-2) at 1, 2, 3, 4, 5, 6 and 7 Jcm-2 in the presence and absence of 10% fetal bovine serum (FBS). Beam profile measurements of the expanded laser beam were conducted to ensure the beam uniformity. The influence of laser dose on the change in temperature was recorded using sensitive temperature probe. Additionally, following laser exposure cell migration and cell survival were documented at different time intervals on wounded human skin fibroblast cells grown in vitro. Beam profile measurements indicated more or less uniform power distribution over the whole beam area. Temperature monitoring of sham irradiated control and laser treatment groups displayed negligible temperature change indicating the absence of thermal effect at the tested laser doses. In the absence of 10% FBS, single exposure of different laser doses failed to produce any significant effects on cell migration or cell survival. However, in the presence of serum single exposure of 5 J/cm2 on wounded skin fibroblasts significantly enhanced the cell migration (P<0.05) compared to the other tested doses (1, 2, 3, 4, 6 and 7 J/cm2) and sham irradiated controls. In conclusion, the LLLT acts by improving cell migration and cell proliferation to produce measurable changes in wounded fibroblast cells.

Dual effect of insulin resistance and cadmium on human granulosa cells - In vitro study

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

Belani, Muskaan, E-mail: muskaanbelani@gmail.com

Combined exposure of cadmium (Cd) and insulin resistance (IR) might be responsible for subfertility. In the present study, we investigated the effects of Cd in vitro in IR human granulosa cells. Isolated human granulosa cells from control and polycystic ovary syndrome (PCOS) follicular fluid samples were confirmed for IR by decrease in protein expression of insulin receptor-β. Control and IR human granulosa cells were then incubated with or without 32 μM Cd. The combined effect of IR with 32 μM Cd in granulosa cells demonstrated significant decrease in expression of StAR, CYP11A1, CYP19A1, 17β-HSD, 3β-HSD, FSH-R and LH-R. Decrease wasmore » also observed in progesterone and estradiol concentrations as compared to control. Additionally, increase in protein expression of cleaved PARP-F2, active caspase-3 and a positive staining for Annexin V and PI indicated apoptosis as the mode of increased cell death ultimately leading to decreased steroidogenesis, as observed through the combined exposure. Taken together the results suggest decrease in steroidogenesis ultimately leading to abnormal development of the follicle thus compromising fertility at the level of preconception. - Highlights: • Protein expression of INSR-β in granulosa cells to differentiate PCOS-IR and NIR • Cd and IR together decrease steroidogenesis in human granulosa cells in vitro. • Cd and IR increase human granulosa cell death by increase in apoptosis. • Environment and life style are set to hamper pregnancies at preconception level.« less

Lack of effects on key cellular parameters of MRC-5 human lung fibroblasts exposed to 370 mT static magnetic field

NASA Astrophysics Data System (ADS)

Romeo, Stefania; Sannino, Anna; Scarfì, Maria Rosaria; Massa, Rita; D'Angelo, Raffaele; Zeni, Olga

2016-01-01

The last decades have seen increased interest toward possible adverse effects arising from exposure to intense static magnetic fields. This concern is mainly due to the wider and wider applications of such fields in industry and clinical practice; among them, Magnetic Resonance Imaging (MRI) facilities are the main sources of exposure to static magnetic fields for both general public (patients) and workers. In recent investigations, exposures to static magnetic fields have been demonstrated to elicit, in different cell models, both permanent and transient modifications in cellular endpoints critical for the carcinogenesis process. The World Health Organization has therefore recommended in vitro investigations as important research need, to be carried out under strictly controlled exposure conditions. Here we report on the absence of effects on cell viability, reactive oxygen species levels and DNA integrity in MRC-5 human foetal lung fibroblasts exposed to 370 mT magnetic induction level, under different exposure regimens. Exposures have been performed by using an experimental apparatus designed and realized for operating with the static magnetic field generated by permanent magnets, and confined in a magnetic circuit, to allow cell cultures exposure in absence of confounding factors like heating or electric field components.

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.

Characterization and Evaluation of a Commercial WLAN System for Human Provocation Studies.

PubMed

Zentai, Norbert; Fiocchi, Serena; Parazzini, Marta; Trunk, Attila; Juhász, Péter; Ravazzani, Paolo; Hernádi, István; Thuróczy, György

2015-01-01

This work evaluates the complex exposure characteristics of Wireless Local Area Network (WLAN) technology and describes the design of a WLAN exposure system built using commercially available modular parts for the study of possible biological health effects due to WLAN exposure in a controlled environment. The system consisted of an access point and a client unit (CU) with router board cards types R52 and R52n with 18 dBm and 25 dBm peak power, respectively. Free space radiofrequency field (RF) measurements were performed with a field meter at a distance of 40 cm from the CU in order to evaluate the RF exposure at several signal configurations of the exposure system. Finally, the specific absorption rate (SAR) generated by the CU was estimated computationally in the head of two human models. Results suggest that exposure to RF fields of WLAN systems strongly depends on the sets of the router configuration: the stability of the exposure was more constant and reliable when both antennas were active and vertically positioned, with best signal quality obtained with the R52n router board at channel 9, in UDP mode. The maximum levels of peak SAR were far away from the limits of international guidelines with peak levels found over the skin.

A paler shade of green? The toxicology of biodiesel emissions ...

EPA Pesticide Factsheets

Background: Biodiesel produced primarily from plants and algal feedstocks is believed to have advantages for production and use compared to petroleum and to some other fuel sources. There is some speculation that exposure to biodiesel combustion emissions may not induce biological responses or health effects or at a minimum reduce the effects relative to other fuels. In evaluating the overall environmental and health effects of biodiesel production to end use scenario, empirical data or modeling data based on such data are needed.Scope of Review: This manuscript examines the available toxicology reports examining combustion derived biodiesel emissions since approximately 2007, when our last review of the topic occurred. Toxicity derived from other end uses of biodiesel- eg, spills, dermal absorption, etc- are not examined. Findings from biodiesel emissions are roughly divided into three areas: whole non-human animal model exposures; in vitro exposures of mammalian and bacterial cells (used for mutation studies primarily); and human exposures in controlled or other exposure fashions. Major Conclusions: Overall, these more current studies clearly demonstrate that biodiesel combustion emission exposure- to either 100% biodiesel or a blend in petroleum diesel- can induce biological effects. There are reports that show biodiesel exposure generally induces more effects or a greater magnitude of effect than petroleum diesel, however there are also a similar number

Characterization and Evaluation of a Commercial WLAN System for Human Provocation Studies

PubMed Central

Parazzini, Marta; Trunk, Attila; Juhász, Péter; Hernádi, István; Thuróczy, György

2015-01-01

This work evaluates the complex exposure characteristics of Wireless Local Area Network (WLAN) technology and describes the design of a WLAN exposure system built using commercially available modular parts for the study of possible biological health effects due to WLAN exposure in a controlled environment. The system consisted of an access point and a client unit (CU) with router board cards types R52 and R52n with 18 dBm and 25 dBm peak power, respectively. Free space radiofrequency field (RF) measurements were performed with a field meter at a distance of 40 cm from the CU in order to evaluate the RF exposure at several signal configurations of the exposure system. Finally, the specific absorption rate (SAR) generated by the CU was estimated computationally in the head of two human models. Results suggest that exposure to RF fields of WLAN systems strongly depends on the sets of the router configuration: the stability of the exposure was more constant and reliable when both antennas were active and vertically positioned, with best signal quality obtained with the R52n router board at channel 9, in UDP mode. The maximum levels of peak SAR were far away from the limits of international guidelines with peak levels found over the skin. PMID:26180791

Lack of effects on key cellular parameters of MRC-5 human lung fibroblasts exposed to 370 mT static magnetic field

PubMed Central

Romeo, Stefania; Sannino, Anna; Scarfì, Maria Rosaria; Massa, Rita; d’Angelo, Raffaele; Zeni, Olga

2016-01-01

The last decades have seen increased interest toward possible adverse effects arising from exposure to intense static magnetic fields. This concern is mainly due to the wider and wider applications of such fields in industry and clinical practice; among them, Magnetic Resonance Imaging (MRI) facilities are the main sources of exposure to static magnetic fields for both general public (patients) and workers. In recent investigations, exposures to static magnetic fields have been demonstrated to elicit, in different cell models, both permanent and transient modifications in cellular endpoints critical for the carcinogenesis process. The World Health Organization has therefore recommended in vitro investigations as important research need, to be carried out under strictly controlled exposure conditions. Here we report on the absence of effects on cell viability, reactive oxygen species levels and DNA integrity in MRC-5 human foetal lung fibroblasts exposed to 370 mT magnetic induction level, under different exposure regimens. Exposures have been performed by using an experimental apparatus designed and realized for operating with the static magnetic field generated by permanent magnets, and confined in a magnetic circuit, to allow cell cultures exposure in absence of confounding factors like heating or electric field components. PMID:26762783

Phase-shifting human circadian rhythms: influence of sleep timing, social contact and light exposure

NASA Technical Reports Server (NTRS)

Duffy, J. F.; Kronauer, R. E.; Czeisler, C. A.

1996-01-01

1. Both the timing of behavioural events (activity, sleep and social interactions) and the environmental light-dark cycle have been reported to contribute to entrainment of human circadian rhythms to the 24 h day. Yet, the relative contribution of those putative behavioural synchronizers to that of light exposure remains unclear. 2. To investigate this, we inverted the schedule of rest, sedentary activity and social contact of thirty-two young men either with or without exposure to bright light. 3. On this inverted schedule, the endogenous component of the core temperature rhythm of subjects who were exposed to bright light showed a significant phase shift, demonstrating that they were adapting to the new schedule. In contrast, the core temperature rhythm of subjects who were not exposed to bright light moved on average 0.2 h later per day and after 10 days had not significantly adapted to the new schedule. 4. The direction of phase shift in the groups exposed to bright light was dependent on the time of bright light exposure, while control subjects drifted to a later hour regardless of the timing of their schedule of sleep timing, social contact and meals. 5. These results support the concept that the light-dark cycle is the most important synchronizer of the human circadian system. They suggest that inversion of the sleep-wake, rest-activity and social contact cycles provides relatively minimal drive for resetting the human circadian pacemaker. 6. These data indicate that interventions designed to phase shift human circadian rhythms for adjustment to time zone changes or altered work schedules should focus on properly timed light exposure.

Cancer mortality in poultry slaughtering/processing plant workers belonging to a union pension fund.

PubMed

Johnson, Eric S; Ndetan, Harrison; Lo, Ka-Ming

2010-08-01

The role of zoonotic biological agents in human cancer occurrence has been little studied. Humans are commonly exposed to viruses that naturally infect and cause cancer in food animals such as poultry that constitute part of the biological environment. It is not known if these viruses cause cancer in humans. To study cancer mortality in the largest cohort to date, of 20,132 workers in poultry slaughtering and processing plants, a group with the highest human exposures to these viruses. Mortality in poultry workers was compared with that in the US general population through the estimation of standardized mortality ratios. Significantly increased risks were observed in the cohort as a whole or in subgroups, for several cancer sites, viz: cancers of the buccal cavity and pharynx; pancreas; trachea/bronchus/lung; brain; cervix; lymphoid leukemia; monocytic leukemia; and tumors of the hemopoietic and lymphatic systems. Elevated SMRs that were not statistically significant were observed for cancers of the liver, nasopharynx, myelofibrosis, and myeloma. New sites observed to be significantly in excess in this study were cancers of the cervix and penis. This large study provides evidence that a human group with high exposure to poultry oncogenic viruses has increased risk of dying from several cancers. Other occupational carcinogenic exposures could be of importance in explaining some of the findings, such as fumes from wrapping machines. These findings may have implications for public health amongst persons in the general population who may also be exposed to these viruses. What is needed now are epidemiologic studies that can demonstrate whether the excess of specific cancers can be attributed to specific occupational exposures while adequately controlling for other potential occupational and non-occupational carcinogenic exposures. Copyright 2010 Elsevier Inc. All rights reserved.

Occupational risk of bladder cancer among Iranian male workers

PubMed Central

Aminian, Omid; Saburi, Amin; Mohseni, Hossein; Akbari, Hamed; Chavoshi, Farzaneh; Akbari, Hesam

2014-01-01

Background: Approximately 5-10% of human cancers are thought to be caused by occupational exposure to carcinogens. Compare to other cancers, bladder cancer is most strongly linked to occupational exposure to chemical toxins. This study has been performed to understand which occupations and exposures are related to bladder cancer in Iran. Materials and Methods: This study is a case-control study which is conducted on cases with bladder cancer (160 cases) diagnosed in Baharlou hospital in 2007-2009. One hundred sixty cases without any occupational exposure were considered as controls matched for demographic characteristics. Demographic data and characteristics of occupation were compared. Results: Mean age of cases and controls were 63.7 and 64 years, respectively (P = 0.841). History of urinary tract stone had significantly difference in two groups (P = 0.039). Occupations such as bus and truck driving, road and asphalt making, mechanics, working in refinery and Petrochemical, plastic, metal manufactory, welding, and pipeline founded a higher risk for bladder cancer rather than controls. Conclusion: Our findings on Iranian workers are concurrent and compatible with findings of previous reports about occupational and environmental risk factors of bladder cancer. Although our study population was PMID:24833825

Evaluation of the antioxidant capacity and preventive effects of a topical emulsion and its vehicle control on the skin response to UV exposure.

PubMed

Zhai, H; Behnam, S; Villarama, C D; Arens-Corell, M; Choi, M J; Maibach, H I

2005-01-01

Supplying topical exogenous antioxidants to the skin may prevent or minimize free radical-induced damaging. This study determines antioxidative capacity of a topical skin care emulsion (an oil-in-water vitamin E-containing formulation) versus its vehicle on human skin that was exposed to ultraviolet radiation (UVR) by utilizing a photochemiluminescence device and biophysical methods. Ten healthy Caucasians (3 male and 7 female; mean age 47 +/- 10 years) were enrolled. In a randomized and double-blind manner, a pH-balanced vitamin E emulsion or its vehicle control was applied onto predesignated forearm prior to UVR exposure. Thirty minutes after application, these test sites were exposed to a UV light to induce the minimal erythema dose. One untreated site served as a blank control. Visual scoring and instrumental measurements were recorded at baseline and at 24 h and 48 h thereafter. At day 3, after completing instrumental measurements, each test site was stripped three times in a consecutive manner with a proprietary adhesive tape disc. These tapes were quantified for antioxidant capacity using a photochemiluminescence device. Vitamin E emulsion and vehicle control significantly (p < 0.05) suppressed visual scores when compared with blank control at day 2 and day 3 after UV exposure. However, vitamin E emulsion showed significantly (p < 0.05) lower visual scores when compared with vehicle control at day 2 and day 3 after UV exposure.Also,vitamin E emulsion and its vehicle control significantly (p < 0.05) diminished skin color measurement (a*) values when compared with blank control at day 2 and day 3 after UV exposure. At day 2 after UV exposure, only vitamin E emulsion significantly (p < 0.05) reduced skin blood flow volume when compared with blank control. Vitamin E emulsion and its vehicle control showed significant (p < 0.05) reduction of blood flow volume when compared with blank control at day 3 after UV exposure. Vitamin E emulsion and its vehicle control proved effective in preventing induction of erythema and reducing inflammatory damage caused by UV exposure. The effect of vitamin E emulsion exceeded that of an 'active control'. Copyright 2005 S. Karger AG, Basel

A Preliminary Study of Biomonitoring for Bisphenol-A in Human Sweat.

PubMed

Porucznik, Christina A; Cox, Kyley J; Wilkins, Diana G; Anderson, David J; Bailey, Nicole M; Szczotka, Kathryn M; Stanford, Joseph B

2015-09-01

Measurement of human exposure to the endocrine disruptor bisphenol-A (BPA) is hampered by the ubiquitous but transient exposure for most individuals, coupled with a short metabolic half-life which leads to high inter- and intra-individual variability. We investigated the possibility of measuring multiday exposure to BPA in human sweat among volunteer participants with the goal of identifying an exposure assessment method less affected by temporal variability. We recruited 50 participants to wear a sweat collection patch (PharmChek(®)) for 7 days with concurrent collection of daily first-morning urine. Urines and sweat patch extracts were analyzed with quantitative LC-MS-MS using a method we previously validated. In addition, a human volunteer consumed one can of commercially available soup (16 oz, 473 cm(3)) daily for 3 days and collected urine. Sweat patches (n = 2, 1 per arm) were worn for the 3 days of the study. BPA was detected in quality control specimens prepared by fortification of BPA to sweat patches, but was only detected at 5× above average background on three participant patches. Although the highest measured urine BPA concentration was 195 ng/mL for an individual with deliberate exposure, no BPA was detected above background in the corresponding sweat patches. In this preliminary investigation, the use of sweat patches primarily worn on the upper-outer arm did not detect BPA exposures that were documented by urine monitoring. The absence of BPA in sweat patches may be due to several factors, including insufficient quantity of specimen per patch, or extremely low concentrations of BPA in naturally occurring sweat, among others. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Arsenic exposure and intestinal microbiota in children from Sirajdikhan, Bangladesh

PubMed Central

Dong, Xiaoxi; Shulzhenko, Natalia; Lemaitre, Julien; Greer, Renee L.; Peremyslova, Kate; Quamruzzaman, Quazi; Rahman, Mahmudar; Hasan, Omar Sharif Ibn; Joya, Sakila Afroz; Golam, Mostofa; Christiani, David C.; Morgun, Andriy

2017-01-01

Background Arsenic has antimicrobial properties at high doses yet few studies have examined its effect on gut microbiota. This warrants investigation since arsenic exposure increases the risk of many diseases in which gut microbiota have been shown to play a role. We examined the association between arsenic exposure from drinking water and the composition of intestinal microbiota in children exposed to low and high arsenic levels during prenatal development and early life. Results 16S rRNA gene sequencing revealed that children with high arsenic exposure had a higher abundance of Proteobacteria in their stool compared to matched controls with low arsenic exposure. Furthermore, whole metagenome shotgun sequencing identified 332 bacterial SEED functions that were enriched in the high exposure group. A separate model showed that these genes, which included genes involved in virulence and multidrug resistance, were positively correlated with arsenic concentration within the group of children in the high arsenic group. We performed reference free genome assembly, and identified strains of E.coli as contributors to the arsenic enriched SEED functions. Further genome annotation of the E.coli genome revealed two strains containing two different arsenic resistance operons that are not present in the gut microbiome of a recently described European human cohort (Metagenomics of the Human Intestinal Tract, MetaHIT). We then performed quantification by qPCR of two arsenic resistant genes (ArsB, ArsC). We observed that the expression of these two operons was higher among the children with high arsenic exposure compared to matched controls. Conclusions This preliminary study indicates that arsenic exposure early in life was associated with altered gut microbiota in Bangladeshi children. The enrichment of E.coli arsenic resistance genes in the high exposure group provides an insight into the possible mechanisms of how this toxic compound could affect gut microbiota. PMID:29211769

Evaluation of neural reflex activation as a mode of action for the acute respiratory effects of ozone.

PubMed

Prueitt, Robyn L; Goodman, Julie E

2016-09-01

Exposure to elevated levels of ozone has been associated with a variety of respiratory-related health endpoints in both epidemiology and controlled human exposure studies, including lung function decrements and airway inflammation. A mode of action (MoA) for these effects has not been established, but it has been proposed that they may occur through ozone-induced activation of neural reflexes. We critically reviewed experimental studies of ozone exposure and neural reflex activation and applied the International Programme on Chemical Safety (IPCS) mode-of-action/human relevance framework to evaluate the biological plausibility and human relevance of this proposed MoA. Based on the currently available experimental data, we found that the proposed MoA of neural reflex activation is biologically plausible for the endpoint of ozone-induced lung function decrements at high ozone exposures, but further studies are needed to fill important data gaps regarding the relevance of this MoA at lower exposures. A role for the proposed MoA in ozone-induced airway inflammation is less plausible, as the evidence is conflicting and is also of unclear relevance given the lack of studies conducted at lower exposures. The evidence suggests a different MoA for ozone-induced inflammation that may still be linked to the key events in the proposed MoA, such that neural reflex activation may have some degree of involvement in modulating ozone-induced neutrophil influx, even if it is not a direct role.

Developmental neurotoxicity of the organophosphorus insecticide chlorpyrifos: from clinical findings to preclinical models and potential mechanisms

PubMed Central

Burke, Richard D.; Todd, Spencer W.; Lumsden, Eric; Mullins, Roger J.; Mamczarz, Jacek; Fawcett, William P.; Gullapalli, Rao P.; Randall, William R.; Pereira, Edna F. R.; Albuquerque, Edson X.

2017-01-01

Organophosphorus (OP) insecticides are pest-control agents heavily used worldwide. Unfortunately, they are also well known for the toxic effects that they can trigger in humans. Clinical manifestations of an acute exposure of humans to OP insecticides include a well-defined cholinergic crisis that develops as a result of the irreversible inhibition of acetylcholinesterase (AChE), the enzyme that hydrolyzes the neurotransmitter acetylcholine (ACh). Prolonged exposures to levels of OP insecticides that are insufficient to trigger signs of acute intoxication, which are hereafter referred to as subacute exposures, have also been associated with neurological deficits. In particular, epidemiological studies have reported statistically significant correlations between prenatal subacute exposures to OP insecticides, including chlorpyrifos, and neurological deficits that range from cognitive impairments to tremors in childhood. The primary objectives of this article are: (i) to address the short- and long-term neurological issues that have been associated with acute and subacute exposures of humans to OP insecticides, especially early in life (ii) to discuss the translational relevance of animal models of developmental exposure to OP insecticides, and (iii) to review mechanisms that are likely to contribute to the developmental neurotoxicity of OP insecticides. Most of the discussion will be focused on chlorpyrifos, the top-selling OP insecticide in the United States and throughout the world. These points are critical for the identification and development of safe and effective interventions to counter and/or prevent the neurotoxic effects of these chemicals in the developing brain. PMID:28791702

Lack of Exposure in a First-in-Man Study Due to Aldehyde Oxidase Metabolism: Investigated by Use of 14C-microdose, Humanized Mice, Monkey Pharmacokinetics, and In Vitro Methods.

PubMed

Jensen, Klaus Gjervig; Jacobsen, Anne-Marie; Bundgaard, Christoffer; Nilausen, Dorrit Østergaard; Thale, Zia; Chandrasena, Gamini; Jørgensen, Martin

2017-01-01

Inclusion of a microdose of 14 C-labeled drug in the first-in-man study of new investigational drugs and subsequent analysis by accelerator mass spectrometry has become an integrated part of drug development at Lundbeck. It has been found to be highly informative with regard to investigations of the routes and rates of excretion of the drug and the human metabolite profiles according to metabolites in safety testing guidance and also when additional metabolism-related issues needed to be addressed. In the first-in-man study with the NCE Lu AF09535, contrary to anticipated, surprisingly low exposure was observed when measuring the parent compound using conventional bioanalysis. Parallel accelerator mass spectrometry analysis revealed that the low exposure was almost exclusively attributable to extensive metabolism. The metabolism observed in humans was mediated via a human specific metabolic pathway, whereas an equivalent extent of metabolism was not observed in preclinical species. In vitro, incubation studies in human liver cytosol revealed involvement of aldehyde oxidase (AO) in the biotransformation of Lu AF09535. In vivo, substantially lower plasma exposure of Lu AF09535 was observed in chimeric mice with humanized livers compared with control animals. In addition, Lu AF09535 exhibited very low oral bioavailability in monkeys despite relatively low clearance after intravenous administration in contrast to the pharmacokinetics in rats and dogs, both showing low clearance and high bioavailability. The in vitro and in vivo methods applied were proved useful for identifying and evaluating AO-dependent metabolism. Different strategies to integrate these methods for prediction of in vivo human clearance of AO substrates were evaluated. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Effects of bright light exposure during daytime on peripheral clock gene expression in humans.

PubMed

Sato, Maki; Wakamura, Tomoko; Morita, Takeshi; Okamoto, Akihiko; Akashi, Makoto; Matsui, Takuya; Sato, Motohiko

2017-06-01

Light is the strongest synchronizer controlling circadian rhythms. The intensity and duration of light change throughout the year, thereby influencing body weight, food preferences, and melatonin secretion in humans and animals. Although the expression of clock genes has been examined using human samples, it currently remains unknown whether bright light during the daytime affects the expression of these genes in humans. Therefore, we herein investigated the effects of bright light exposure during the daytime on clock gene expression in the hair follicular and root cells of the human scalp. Seven healthy men (20.4 ± 2.2 years old; 172.3 ± 5.8 cm; 64.3 ± 8.5 kg; BMI 21.7 ± 3.1 kg/m 2 , mean ± SD) participated in this study. Subjects completed 3-day experimental sessions twice in 1 month during which they were exposed to bright and dim light conditions. The mRNA expression of Per1-3, Cry1-2, Rev-erb-α (Nr1d1), Rev-erb-β (Nr1d2), and Dec1 was analyzed using branched DNA probes. No significant changes were observed in the expression of Per1, Per2, Per3, Cry1, Cry2, Rev-erb-α (Nr1d1), or Dec1 following exposure to bright light conditions. However, the expression of Rev-erb-β (Nr1d2) tended to be stronger under bright light than dim light conditions. These results suggest that the bright light stimulus did not influence the expression of clock genes in humans. Long-lasting bright light exposure during the daytime may be required to change the expression of clock genes in humans.

A systematic review of Bisphenol A "low dose" studies in the context of human exposure: a case for establishing standards for reporting "low-dose" effects of chemicals.

PubMed

Teeguarden, Justin G; Hanson-Drury, Sesha

2013-12-01

Human exposure to the chemical Bisphenol A is almost ubiquitous in surveyed industrialized societies. Structural features similar to estrogen confer the ability of Bisphenol A (BPA) to bind estrogen receptors, giving BPA membership in the group of environmental pollutants called endocrine disruptors. References by scientists, the media, political entities, and non-governmental organizations to many toxicity studies as "low dose" has led to the belief that exposure levels in these studies are similar to humans, implying that BPA is toxic to humans at current exposures. Through systematic, objective comparison of our current, and a previous compilation of the "low-dose" literature to multiple estimates of human external and internal exposure levels, we found that the "low-dose" moniker describes exposures covering 8-12 orders of magnitude, the majority (91-99% of exposures) being greater than the upper bound of human exposure in the general infant, child and adult U.S. Population. "low dose" is therefore a descriptor without specific meaning regarding human exposure. Where human exposure data are available, for BPA and other environmental chemicals, reference to toxicity study exposures by direct comparison to human exposure would be more informative, more objective, and less susceptible to misunderstanding. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of diesel exhaust generated by a city bus engine on stress responses and innate immunity in primary bronchial epithelial cell cultures.

PubMed

Zarcone, M C; Duistermaat, E; Alblas, M J; van Schadewijk, A; Ninaber, D K; Clarijs, V; Moerman, M M; Vaessen, D; Hiemstra, P S; Kooter, I M

2018-04-01

Harmful effects of diesel emissions can be investigated via exposures of human epithelial cells, but most of previous studies have largely focused on the use of diesel particles or emission sources that are poorly representative of engines used in current traffic. We studied the cellular response of primary bronchial epithelial cells (PBECs) at the air-liquid interface (ALI) to the exposure to whole diesel exhaust (DE) generated by a Euro V bus engine, followed by treatment with UV-inactivated non-typeable Haemophilus influenzae (NTHi) bacteria to mimic microbial exposure. The effect of prolonged exposures was investigated, as well as the difference in the responses of cells from COPD and control donors and the effect of emissions generated during a cold start. HMOX1 and NQO1 expression was transiently induced after DE exposure. DE inhibited the NTHi-induced expression of human beta-defensin-2 (DEFB4A) and of the chaperone HSPA5/BiP. In contrast, expression of the stress-induced PPP1R15A/GADD34 and the chemokine CXCL8 was increased in cells exposed to DE and NTHi. HMOX1 induction was significant in both COPD and controls, while inhibition of DEFB4A expression by DE was significant only in COPD cells. No significant differences were observed when comparing cellular responses to cold engine start and prewarmed engine emissions. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

[Effects of n-hexane exposure on human serum myelin basic proteins].

PubMed

Zhou, Wei; Yi, Juan; Huang, Hui-Ping; Xiang, Ying-Ping; He, Jia-Xi; Liu, Qing-Jun; Huang, Xian-Qing

2011-06-01

To explore the effects of n-hexane on expression of serum myelin proteins (MBP) in workers occupationally exposed to n-hexane. In this study, 269 workers exposed to n-hexane for more than one year and 104 subjects not exposed to n-hexane served as the exposure group and the control group, respectively. The urinary 2,5-hexanedione levels in all subjects were detected. On the basis of urinary 2,5-hexanedione levels, the exposure group was divided into the high exposure sub-group and low exposure sub-group. The serum myelin basic protein (MBP) levels were measured by ELISA kit. The mean concentration of urinary 2,5-hexanedione in the exposed group was (3.10 +/- 1.35) mg/L. The concentration of urinary 2,5-hexanedione in the control group was undetectable. The levels of serum MBP in the high exposure sub-group and low exposure sub-group were (2.43 +/- 0.24) and (1.62 +/- 0.23) microg/L, respectively, which were significantly higher than that (0.78 +/- 0.12) microg/L in the controls (P < 0.01). Pearson correlation analysis showed the positive correlation between serum MBP levels and urinary 2,5-hexanedione levels (r = 0.781, P < 0.01). The results of present study showed that the serum MBP levels of workers occupationally exposed to n-hexane significantly elevated, and the serum MBP can serve as the effective biomarker of n-hexane exposure.

Effects of 3G cell phone exposure on the structure and function of the human cytochrome P450 reductase.

PubMed

Tanvir, Shazia; Thuróczy, György; Selmaoui, Brahim; Silva Pires Antonietti, Viviane; Sonnet, Pascal; Arnaud-Cormos, Delia; Lévêque, Philippe; Pulvin, Sylviane; de Seze, René

2016-10-01

Cell phones increase exposure to radiofrequency (RF) electromagnetic fields (EMFs). Whether EMFs exert specific effects on biological systems remains debatable. This study investigated the effect of cell phone exposure on the structure and function of human NADPH-cytochrome P450 reductase (CPR). CPR plays a key role in the electron transfer to cytochrome P450, which takes part in a wide range of oxidative metabolic reactions in various organisms from microbes to humans. Human CPR was exposed for 60min to 1966-MHz RF inside a transverse electromagnetic cell (TEM-cell) placed in an incubator. The specific absorption rate (SAR) was 5W·kg(-1). Conformation changes have been detected through fluorescent spectroscopy of flavin and tryptophan residues, and investigated through circular dichroism, dynamic light scattering and microelectrophoresis. These showed that CPR was narrowed. By using cytochrome C reductase activity to assess the electron flux through the CPR, the Michaelis Menten constant (Km) and the maximum initial velocity (Vmax) decreased by 22% as compared with controls. This change was due to small changes in the tertiary and secondary structures of the protein at 37°C. The relevance of these findings to an actual RF exposure scenario demands further biochemical and in-vivo confirmation. Copyright © 2016 Elsevier B.V. All rights reserved.

Biodiesel exhaust-induced cytotoxicity and proinflammatory mediator production in human airway epithelial cells.

PubMed

Mullins, Benjamin J; Kicic, Anthony; Ling, Kak-Ming; Mead-Hunter, Ryan; Larcombe, Alexander N

2016-01-01

Increasing use of biodiesel has prompted research into the potential health effects of biodiesel exhaust exposure. Few studies directly compare the health consequences of mineral diesel, biodiesel, or blend exhaust exposures. Here, we exposed human epithelial cell cultures to diluted exhaust generated by the combustion of Australian ultralow-sulfur-diesel (ULSD), unprocessed canola oil, 100% canola biodiesel (B100), and a blend of 20% canola biodiesel mixed with 80% ULSD. The physicochemical characteristics of the exhaust were assessed and we compared cellular viability, apoptosis, and levels of interleukin (IL)-6, IL-8, and Regulated on Activation, Normal T cell Expressed and Secreted (RANTES) in exposed cultured cells. Different fuel types produced significantly different amounts of exhaust gases and different particle characteristics. All exposures resulted in significant apoptosis and loss of viability when compared with control, with an increasing proportion of biodiesel being correlated with a decrease in viability. In most cases, exposure to exhaust resulted in an increase in mediator production, with the greatest increases most often in response to B100. Exposure to pure canola oil (PCO) exhaust did not increase mediator production, but resulted in a significant decrease in IL-8 and RANTES in some cases. Our results show that canola biodiesel exhaust exposure elicits inflammation and reduces viability of human epithelial cell cultures in vitro when compared with ULSD exhaust exposure. This may be related to an increase in particle surface area and number in B100 exhaust when compared with ULSD exhaust. Exposure to PCO exhaust elicited the greatest loss of cellular viability, but virtually no inflammatory response, likely due to an overall increase in average particle size. © 2014 Wiley Periodicals, Inc.

Chlorine Isotopic Composition of Perchlorate in Human Urine as a Means of Distinguishing Among Natural and Synthetic Exposure Sources

PubMed Central

Poghosyan, Armen; Morel-Espinosa, Maria; Valentín-Blasini, Liza; Blount, Benjamin C.; Ferreccio, Catterina; Steinmaus, Craig M.; Sturchio, Neil C.

2015-01-01

Perchlorate (ClO4−) is a ubiquitous environmental contaminant with high human exposure potential; it has both natural and man-made sources in the environment. Natural perchlorate forms in the atmosphere from where it deposits onto the surface of Earth, whereas synthetic perchlorate is manufactured as an oxidant for industrial, aerospace, and military applications. Perchlorate exposure can potentially cause adverse health effects in humans by interfering with the production of thyroid hormones through competitively blocking iodide uptake. To control and reduce perchlorate exposure, the contributions of different sources of perchlorate exposure need to be quantified. Thus, we demonstrate a novel approach for determining the contribution of different perchlorate exposure sources by quantifying stable and radioactive chlorine isotopes of perchlorate extracted from composite urine samples from two distinct populations: one in Atlanta, USA and one in Taltal, Chile (Atacama region). Urinary perchlorate from the Atlanta region resembles indigenous natural perchlorate from the southwestern USA [δ37Cl = +4.1 ± 1.0 ‰; 36Cl/Cl = 1811 (± 136) × 10−15], and urinary perchlorate from the Taltal, Chile region is similar to natural perchlorate in nitrate salt deposits from the Atacama Desert of northern Chile [δ37Cl = −11.0 ± 1.0 ‰; 36Cl/Cl = 254 (± 40) × 10−15]. Neither urinary perchlorate resembled the isotopic pattern found in synthetic perchlorate. These results indicate that natural perchlorate of regional provenance is the dominant exposure source for the two sample populations, and that chlorine isotope ratios provide a robust tool for elucidating perchlorate exposure pathways. PMID:25805252

Effect of localizer radiograph on radiation dose associated with automatic exposure control: human cadaver and patient study.

PubMed

Singh, Sarabjeet; Petrovic, Dean; Jamnik, Ethen; Aran, Shima; Pourjabbar, Sarvenaz; Kave, Maggie L; Bradley, Stephen E; Choy, Garry; Kalra, Mannudeep K

2014-01-01

To evaluate the effect of localizing radiograph on computed tomography (CT) radiation dose associated with automatic exposure control with a human cadaver and patient study. Institutional review board approved the study with a waiver of informed consent. Two chest CT image series with fixed tube current and combined longitudinal-angular automatic exposure control (AEC) were acquired in a human cadaver (64-year-old man) after each of the 8 combinations of localizer radiographs (anteroposterior [AP], AP lateral, AP-posteroanterior [PA], lateral AP, lateral PA, PA, PA-AP, and PA lateral). Applied effective milliampere second, volume CT dose index (CTDIvol) and image noise were recorded for all 24-image series. Volume CT dose indexes were also recorded in 20 patients undergoing chest and abdominal CT after PA and PA-lateral radiographs with the use of AEC. Data were analyzed using analysis of variance and linear correlation tests. With AEC, the CTDIvol fluctuates with the number and projection of localizer radiographs (P < 0.0001). Lowest CTDIvol values are seen when 2 orthogonal localizer radiographs are acquired, whereas highest values are seen when single PA or AP-PA projection localizer radiographs are acquired for planning (P < 0.0001). In 20 patients, CT scanning with AEC after acquisition of 2 orthogonal projection localizer radiographs was associated with significant reduction in radiation dose compared to PA projection radiographs alone (P < 0.0001). When scanning with AEC, acquisition of 2 orthogonal localizer radiographs is associated with lower CTDIvol compared to a single localizer radiograph.

Alterations in the Spectrum of Spontaneous Rifampicin-Resistance Mutations in the Bacillus subtilis rpoB Gene after Cultivation in the Human Spaceflight Environment

PubMed Central

Fajardo-Cavazos, Patricia; Leehan, Joshua D.; Nicholson, Wayne L.

2018-01-01

The effect of Bacillus subtilis exposure to the human spaceflight environment on growth, mutagenic frequency, and spectrum of mutations to rifampicin resistance (RifR) was investigated. B. subtilis cells were cultivated in Biological Research in Canister-Petri Dish Fixation Units (BRIC-PDFUs) on two separate missions to the International Space Station (ISS), dubbed BRIC-18 and BRIC-21, with matching asynchronous ground controls. No statistically significant difference in either growth or in the frequency of mutation to RifR was found in either experiment. However, nucleotide sequencing of the RifR regions of the rpoB gene from RifR mutants revealed dramatic differences in the spectrum of mutations between flight (FL) and ground control (GC) samples, including two newly discovered rpoB alleles in the FL samples (Q137R and L489S). The results strengthen the idea that exposure to the human spaceflight environment causes unique stresses on bacteria, leading to alterations in their mutagenic potential. PMID:29491852

[Wood smoke condensate induced epithelial-mesenchymal transition in human airway epithelial cells].

PubMed

Li, Wenxi; Zou, Weifeng; Li, Bing; Ran, Pixin

2014-01-01

To observe the detrimental effects of wood smoke condensate (WSC) exposure on human bronchial epithelial cells (HBEC), and to explore the expression of epithelial-mesenchymal transition (EMT) markers in HBEC exposed to WSC. HBEC were exposed respectively to 5, 10, 20, 40 and 50 mg/L of WSC /CSC for 7 days, with control groups only in cell culture medium at the same time, then the total cytoactivity was detected by cell counting kit-8. After observing the cellular morphology of WSC-stimulated HBEC. Western blot and immunofluorescence method were used to evaluate the expression levels of type I collagen, vimentin, E-cad and MMP-9 in HBEC exposed to WSC (10 mg/L) and cigarette smoke condensate (CSC) (10 mg/L) for 7 days. Statistical evaluation of the continuous data was performed by ANOVA. Independent-Samples t-test for between-group comparisons. After 7 days of exposure to WSC, HBEC manifested a morphological characteristic of loss of cell-cell contact and elongated shape. The level of E-cad was decreased in WSC exposure groups (Western blot: 0.30 ± 0.05, F = 22.07, P < 0.05) compared with the groups without WSC exposure (Western blot: 0.59 ± 0.08, F = 22.07, P < 0.05). In contrast, an upregulation in expression of type I collagen (Western blot: 0.58 ± 0.04 vs 0.26 ± 0.02, F = 119.72, P < 0.05) and MMP-9 (0.56 ± 0.08 vs 0.19 ± 0.03, F = 21.79, P < 0.05) was observed in the presence of WSC, compared with the control groups. Immunofluorescence analysis showed that after a 7-day exposure to WSC in these cells, the E-cad protein was lost whereas type I collagen, vimentin and MMP-9 were acquired. Both Western blot and immunofluorescence analysis showed no difference in expression levels of E-cad, type I collagen, vimentin and MMP-9 between WSC and CSC exposure groups. WSC exposure could induce EMT-like process in human airway epithelial cells.

Disposition of the Dietary Mutagen 2-Amino-3,8-dimethylimidazo[4,5- f ]quinoxaline in Healthy and Pancreatic Cancer Compromised Humans

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

Malfatti, Michael A.; Kuhn, Edward A.; Turteltaub, Kenneth W.

Pancreatic cancer is the fourth leading cause of cancer death in the U.S. Once diagnosed, prognosis is poor with a 5-year survival rate of less than 5%. Exposure to carcinogenic heterocyclic amines (HCAs) derived from cooked meat has been shown to be positively associated with pancreatic cancer risk. To evaluate the processes that determines the carcinogenic potential of HCAs for human pancreas, 14-carbon labeled 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), a putative human carcinogenic HCA found in well-done cooked meat, was administered at a dietary relevant dose to human volunteers diagnosed with pancreatic cancer undergoing partial pancreatectomy and healthy control volunteers. After 14C-MeIQx exposure,more » blood and urine was collected for pharmacokinetic and metabolite analysis. MeIQx-DNA adducts levels were quantified by accelerator mass spectrometry from pancreatic tissue excised during surgery from the cancer patient group. Pharmacokinetic analysis of plasma revealed a rapid distribution of MeIQx with a plasma elimination half-life of approximately 3.5 hr in 50% of the cancer patients and all of the control volunteers. In 2 of the 4 cancer patients very low levels of MeIQx were detected in plasma and urine suggesting low absorption from the gut into the plasma. Urinary metabolite analysis revealed five MeIQx metabolites with 2-amino-3-methylimidazo[4,5-f]quinoxaline-8-carboxylic acid being the most abundant accounting for 25%–50% of the recovered 14-carbon/ml urine. We found there was no discernable difference in metabolite levels between the cancer patient volunteers and the control group. MeIQx-DNA adduct analysis of pancreas and duodenum tissue revealed adduct levels indistinguishable from background levels. Lastly, although other meat-derived HCA mutagens have been shown to bind DNA in pancreatic tissue, indicating that exposure to HCAs from cooked meat cannot be discounted as a risk factor for pancreatic cancer, the results from this current study show that exposure to a single dietary dose of MeIQx does not readily form measurable DNA adducts under the conditions of the experiment.« less

Disposition of the Dietary Mutagen 2-Amino-3,8-dimethylimidazo[4,5- f ]quinoxaline in Healthy and Pancreatic Cancer Compromised Humans

DOE PAGES

Malfatti, Michael A.; Kuhn, Edward A.; Turteltaub, Kenneth W.; ...

2016-02-26

Pancreatic cancer is the fourth leading cause of cancer death in the U.S. Once diagnosed, prognosis is poor with a 5-year survival rate of less than 5%. Exposure to carcinogenic heterocyclic amines (HCAs) derived from cooked meat has been shown to be positively associated with pancreatic cancer risk. To evaluate the processes that determines the carcinogenic potential of HCAs for human pancreas, 14-carbon labeled 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), a putative human carcinogenic HCA found in well-done cooked meat, was administered at a dietary relevant dose to human volunteers diagnosed with pancreatic cancer undergoing partial pancreatectomy and healthy control volunteers. After 14C-MeIQx exposure,more » blood and urine was collected for pharmacokinetic and metabolite analysis. MeIQx-DNA adducts levels were quantified by accelerator mass spectrometry from pancreatic tissue excised during surgery from the cancer patient group. Pharmacokinetic analysis of plasma revealed a rapid distribution of MeIQx with a plasma elimination half-life of approximately 3.5 hr in 50% of the cancer patients and all of the control volunteers. In 2 of the 4 cancer patients very low levels of MeIQx were detected in plasma and urine suggesting low absorption from the gut into the plasma. Urinary metabolite analysis revealed five MeIQx metabolites with 2-amino-3-methylimidazo[4,5-f]quinoxaline-8-carboxylic acid being the most abundant accounting for 25%–50% of the recovered 14-carbon/ml urine. We found there was no discernable difference in metabolite levels between the cancer patient volunteers and the control group. MeIQx-DNA adduct analysis of pancreas and duodenum tissue revealed adduct levels indistinguishable from background levels. Lastly, although other meat-derived HCA mutagens have been shown to bind DNA in pancreatic tissue, indicating that exposure to HCAs from cooked meat cannot be discounted as a risk factor for pancreatic cancer, the results from this current study show that exposure to a single dietary dose of MeIQx does not readily form measurable DNA adducts under the conditions of the experiment.« less

The human body odor compound androstadienone leads to anger-dependent effects in an emotional Stroop but not dot-probe task using human faces.

PubMed

Hornung, Jonas; Kogler, Lydia; Wolpert, Stephan; Freiherr, Jessica; Derntl, Birgit

2017-01-01

The androgen derivative androstadienone is a substance found in human sweat and thus is a putative human chemosignal. Androstadienone has been studied with respect to effects on mood states, attractiveness ratings, physiological and neural activation. With the current experiment, we aimed to explore in which way androstadienone affects attention to social cues (human faces). Moreover, we wanted to test whether effects depend on specific emotions, the participants' sex and individual sensitivity to smell androstadienone. To do so, we investigated 56 healthy individuals (thereof 29 females taking oral contraceptives) with two attention tasks on two consecutive days (once under androstadienone, once under placebo exposure in pseudorandomized order). With an emotional dot-probe task we measured visuo-spatial cueing while an emotional Stroop task allowed us to investigate interference control. Our results suggest that androstadienone acts in a sex, task and emotion-specific manner as a reduction in interference processes in the emotional Stroop task was only apparent for angry faces in men under androstadienone exposure. More specifically, men showed a smaller difference in reaction times for congruent compared to incongruent trials. At the same time also women were slightly affected by smelling androstadienone as they classified angry faces more often correctly under androstadienone. For the emotional dot-probe task no modulation by androstadienone was observed. Furthermore, in both attention paradigms individual sensitivity to androstadienone was neither correlated with reaction times nor error rates in men and women. To conclude, exposure to androstadienone seems to potentiate the relevance of angry faces in both men and women in connection with interference control, while processes of visuo-spatial cueing remain unaffected.

The human body odor compound androstadienone leads to anger-dependent effects in an emotional Stroop but not dot-probe task using human faces

PubMed Central

Kogler, Lydia; Wolpert, Stephan; Freiherr, Jessica; Derntl, Birgit

2017-01-01

The androgen derivative androstadienone is a substance found in human sweat and thus is a putative human chemosignal. Androstadienone has been studied with respect to effects on mood states, attractiveness ratings, physiological and neural activation. With the current experiment, we aimed to explore in which way androstadienone affects attention to social cues (human faces). Moreover, we wanted to test whether effects depend on specific emotions, the participants' sex and individual sensitivity to smell androstadienone. To do so, we investigated 56 healthy individuals (thereof 29 females taking oral contraceptives) with two attention tasks on two consecutive days (once under androstadienone, once under placebo exposure in pseudorandomized order). With an emotional dot-probe task we measured visuo-spatial cueing while an emotional Stroop task allowed us to investigate interference control. Our results suggest that androstadienone acts in a sex, task and emotion-specific manner as a reduction in interference processes in the emotional Stroop task was only apparent for angry faces in men under androstadienone exposure. More specifically, men showed a smaller difference in reaction times for congruent compared to incongruent trials. At the same time also women were slightly affected by smelling androstadienone as they classified angry faces more often correctly under androstadienone. For the emotional dot-probe task no modulation by androstadienone was observed. Furthermore, in both attention paradigms individual sensitivity to androstadienone was neither correlated with reaction times nor error rates in men and women. To conclude, exposure to androstadienone seems to potentiate the relevance of angry faces in both men and women in connection with interference control, while processes of visuo-spatial cueing remain unaffected. PMID:28369152

Brain magnetic resonance imaging and manganese concentrations in red blood cells of smelting workers: Search for biomarkers of manganese exposure

PubMed Central

Jiang, Yueming; Zheng, Wei; Long, Liling; Zhao, Weijia; Li, Xiangrong; Mo, Xuean; Lu, Jipei; Fu, Xue; Li, Wenmei; Liu, Shouting; Long, Quanyong; Huang, Jinli; Pira, Enrico

2014-01-01

The MRI technique has been used in diagnosis of manganism in humans and non-human primates. This cross-sectional study was designed to explore whether the pallidal signal intensity in T1-weighted MRI correlated with Mn levels in the blood compartment among Mn-exposed workers and to understand to what extent the MRI signal could reflect Mn exposure. A group of 18 randomly selected male Mn-exposed workers of which 13 were smelting workers with high exposure (mean of airborne Mn in work place: 1.26 mg/m3; range: 0.31–2.93 mg/m3), and 5 power distribution control workers with low exposure (0.66 mg/m3 and 0.23–0.77 mg/m3) from a ferroalloy factory, and another group of 9 male subjects as controls from a non-smelting factory who were office or cafeteria workers (0.01 mg/m3 and 0–0.03 mg/m3) were recruited for neurological tests, MRI examination, and analysis of Mn in whole blood (MnB), plasma (MnP) or red blood cells (MnRBC). No clinical symptoms and signs of manganism were observed among these workers. MRI data showed average increases of 7.4% (p < 0.05) and 16.1% (p < 0.01) in pallidal index (PI) among low- and high-exposed workers, respectively, as compared to controls. Fourteen out of 18 Mn-exposed workers (78%) had intensified PI values, while this proportion was even higher (85%) among the high Mn-exposed workers. Among exposed workers, the PI values were significantly associated with MnRBC (r = 0.55, p = 0.02). Our data suggest that the workers exposed to airborne Mn, but without clinical symptoms, display an exposure-related, intensified MRI signal. The MRI, as well as MnRBC, may be useful in early diagnosis of Mn exposure. PMID:16978697

Brain magnetic resonance imaging and manganese concentrations in red blood cells of smelting workers: search for biomarkers of manganese exposure.

PubMed

Jiang, Yueming; Zheng, Wei; Long, Liling; Zhao, Weijia; Li, Xiangrong; Mo, Xuean; Lu, Jipei; Fu, Xue; Li, Wenmei; Liu, Shouting; Long, Quanyong; Huang, Jinli; Pira, Enrico

2007-01-01

The MRI technique has been used in diagnosis of manganism in humans and non-human primates. This cross-sectional study was designed to explore whether the pallidal signal intensity in T1-weighted MRI correlated with Mn levels in the blood compartment among Mn-exposed workers and to understand to what extent the MRI signal could reflect Mn exposure. A group of 18 randomly selected male Mn-exposed workers of which 13 were smelting workers with high exposure (mean of airborne Mn in work place: 1.26 mg/m3; range: 0.31-2.93 mg/m3), and 5 power distribution control workers with low exposure (0.66 mg/m3 and 0.23-0.77 mg/m3) from a ferroalloy factory, and another group of 9 male subjects as controls from a non-smelting factory who were office or cafeteria workers (0.01 mg/m3 and 0-0.03 mg/m3) were recruited for neurological tests, MRI examination, and analysis of Mn in whole blood (MnB), plasma (MnP) or red blood cells (MnRBC). No clinical symptoms and signs of manganism were observed among these workers. MRI data showed average increases of 7.4% (p<0.05) and 16.1% (p<0.01) in pallidal index (PI) among low- and high-exposed workers, respectively, as compared to controls. Fourteen out of 18 Mn-exposed workers (78%) had intensified PI values, while this proportion was even higher (85%) among the high Mn-exposed workers. Among exposed workers, the PI values were significantly associated with MnRBC (r=0.55, p=0.02). Our data suggest that the workers exposed to airborne Mn, but without clinical symptoms, display an exposure-related, intensified MRI signal. The MRI, as well as MnRBC, may be useful in early diagnosis of Mn exposure.

PBB episode in Michigan: an overall appraisal

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

Fries, G.F.

1985-01-01

Polybrominated biphenyls (PBB) were used as a fire retardant. In common with other halogenated hydrocarbons, PBBs are lipophilic and resistant to chemical and metabolic degradation. Cattle on about 25 Michigan farms were exposed to as much as 250 g per head of PBB when it was accidentally mixed in cattle feed in 1973 to 1974. Livestock exposures several orders of magnitude lower occurred on several hundred other farms because of carryover and equipment contamination in feed mills. Approximately 85% of the Michigan population received some exposure to PBB because dairy product marketing involves mixing milk from many farms. A fewmore » cases of high human exposure, which may have been as great as 10 g, occurred when residents of the more highly exposed farms consumed their own products. Although numerous clinical signs and pathological changes were reported in exposed cattle, only anorexia, lacrimation, emaciation, hyperkeratosis, and kidney damage were confirmed in controlled studies. The acute toxicity of PBB in laboratory animals is low, but a variety of subacute effects have been reported. Induction of microsomal enzymes, enlargement and histopathological changes of the liver, fetotoxicity, and immunosuppression are among the more significant. Epidemiological studies of exposed humans have revealed no pattern of clinical signs or symptoms that were related to PBB exposure. A complete evaluation of the human consequences of exposure to PBB await the conclusion of long-term epidemiological studies. 84 references.« less

A Comparison of Model Calculation and Measurement of Absorbed Dose for Proton Irradiation. Chapter 5

NASA Technical Reports Server (NTRS)

Zapp, N.; Semones, E.; Saganti, P.; Cucinotta, F.

2003-01-01

With the increase in the amount of time spent EVA that is necessary to complete the construction and subsequent maintenance of ISS, it will become increasingly important for ground support personnel to accurately characterize the radiation exposures incurred by EVA crewmembers. Since exposure measurements cannot be taken within the organs of interest, it is necessary to estimate these exposures by calculation. To validate the methods and tools used to develop these estimates, it is necessary to model experiments performed in a controlled environment. This work is such an effort. A human phantom was outfitted with detector equipment and then placed in American EMU and Orlan-M EVA space suits. The suited phantom was irradiated at the LLUPTF with proton beams of known energies. Absorbed dose measurements were made by the spaceflight operational dosimetrist from JSC at multiple sites in the skin, eye, brain, stomach, and small intestine locations in the phantom. These exposures are then modeled using the BRYNTRN radiation transport code developed at the NASA Langley Research Center, and the CAM (computerized anatomical male) human geometry model of Billings and Yucker. Comparisons of absorbed dose calculations with measurements show excellent agreement. This suggests that there is reason to be confident in the ability of both the transport code and the human body model to estimate proton exposure in ground-based laboratory experiments.

An Investigation on the Effect of Extremely Low Frequency Pulsed Electromagnetic Fields on Human Electrocardiograms (ECGs).

PubMed

Fang, Qiang; Mahmoud, Seedahmed S; Yan, Jiayong; Li, Hui

2016-11-23

For this investigation, we studied the effects of extremely low frequency pulse electromagnetic fields (ELF-PEMF) on the human cardiac signal. Electrocardiograms (ECGs) of 22 healthy volunteers before and after a short duration of ELF-PEMF exposure were recorded. The experiment was conducted under single-blind conditions. The root mean square (RMS) value of the recorded data was considered as comparison criteria. We also measured and analysed four important ECG time intervals before and after ELF-PEMF exposure. Results revealed that the RMS value of the ECG recordings from 18 participants (81.8% of the total participants) increased with a mean value of 3.72%. The increase in ECG voltage levels was then verified by a second experimental protocol with a control exposure. In addition to this, we used hyperbolic T-distributions (HTD) in the analysis of ECG signals to verify the change in the RR interval. It was found that there were small shifts in the frequency-domain signal before and after EMF exposure. This shift has an influence on all frequency components of the ECG signals, as all spectrums were shifted. It is shown from this investigation that a short time exposure to ELF-PEMF can affect the properties of ECG signals. Further study is needed to consolidate this finding and discover more on the biological effects of ELF-PEMF on human physiological processes.

Evaluation of genotoxic and oxidative effects in workers exposed to jet propulsion fuel.

PubMed

Erdem, Onur; Sayal, Ahmet; Eken, Ayşe; Akay, Cemal; Aydın, Ahmet

2012-05-01

Jet fuel is a common occupational exposure risk among military and civilian populations. The purpose of this study was to evaluate genotoxic and oxidative effects in workers occupational exposure to jet propulsion fuel (JP-8). In this study, sister-chromatid exchange (SCE), high frequency of SCE cells (HFCs), and micronuclei (MN) were determined for 43 workers exposed to JP-8 and 38 control subjects. We measured the antioxidant enzyme activities including that of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT). The levels of thiobarbituric acid-reactive substances (TBARS) were also studied. Urinary 1- and 2-naphthol excretion was used as a biomarker of occupational exposure to JP-8. The results obtained from cytogenetic analysis show a statistically significant increase in frequency of SCE in the exposed workers when compared to controls (P < 0.05). Interestingly, the mean value of the frequency (%o) of MN and HFCs for workers and controls did not show any statistical differences (P > 0.05). Oxidative stress parameters were not statistically different between exposed and control groups except for TBARS levels. Urinary 1-and 2-naphthol levels of exposed workers were found to be significantly higher than those of control subjects. Occupational exposure to JP-8 resulted in no significant genotoxic and oxidative effects, while smoking is the principal confounding factor for the some parameters. To understand the genotoxic and oxidative effects of JP-8 exposure, further studies should be planned to find out whether human populations may be at increased risk for cancer because of the exposures related to occupation and lifestyle.

ANALYSIS OF HUMAN ACTIVITY DATA FOR USE IN MODELING ENVIRONMENTAL EXPOSURES

EPA Science Inventory

Human activity data are a critical part of exposure models being developed by the US EPA's National Exposure Research Laboratory (NERL). An analysis of human activity data within NERL's Consolidated Human Activity Database (CHAD) was performed in two areas relevant to exposure ...

Acute hydrofluoric acid exposure reported to Taiwan Poison Control Center, 1991-2010.

PubMed

Wu, M-L; Yang, C-C; Ger, J; Tsai, W-J; Deng, J-F

2014-05-01

Hydrofluoric acid (HF) is a dangerous chemical that can cause severe cutaneous burns as well as possible systemic toxicity. We retrospectively analyzed all human HF exposure cases reported to the National Poison Control Center of Taiwan between 1991 and 2010. In this 20-year survey, 324 calls were identified, with a majority of dermal exposure (84%). Occupational exposure accounted for 80% of all cases, with workers in semiconductor industry (61%), cleaning industry (15%), chemical or metal industry (13%), and other industries (11%). Electrolyte imbalances were uncommon, hypocalcemia, hypomagnesemia, and hypokalemia were recorded in 8.6%, 1.2%, and 1.5% of all cases, respectively. Most cases (64%) of dermal exposure received antidotal treatment. Treatment modalities of dermal exposure included calcium gluconate soaking, 49.8%; intravenous calcium, 20.6%; and topical use of calcium gluconate gel, 13.9%. Twenty patients (7%) received surgery. Following HF exposure, the majority of patients presented with mild (56.5%) or moderate (36.7%) toxic effects. However, four patients were severely intoxicated; two patients died of HF-related dysrhythmia and shock. Significant symptomology may occur following HF exposure, and most of the HF exposure required hospitals evaluation. Calcium gluconate soaks appear to be effective in reducing local pain and tissue damage. Hyperkalemia should not be overemphasized as a common finding in HF exposure, hypokalemia tends to occur in cases of severe HF poisoning.

Human 8-oxoguanine DNA glycosylase 1 mRNA expression as an oxidative stress exposure biomarker of cooking oil fumes.

PubMed

Cherng, Shur-Hueih; Huang, Kuo Hao; Yang, Sen-Chih; Wu, Tzu-Chin; Yang, Jia-Ling; Lee, Huei

2002-02-01

Epidemiological studies have indicated that the exposure to carcinogenic components formed during the cooking of food might be associated with lung cancer risk of Chinese women. Previous studies have confirmed that cooking oil fumes from frying fish (COF) contained relatively high amount of benzo[a]pyrene, 2-methyl-3,8-dimethylimidazo[4,5-f] qunoxaline, benzene, and 1,3-butadiene, reported in fumes from heated soybean oil. Thus, we consider that oxidative stress induced by COF may play a role in lung cancer development among Chinese women. To verify whether the oxidative DNA damage was induced by COF, high-performance liquid chromatography (HPLC) analysis data showed that the levels of 8-hydroxydeoxyguanine (8-OH dG) were increased in a dose-dependent manner when calf thymus DNA reacted with various concentrations of COF. Since human 8-oxoguanine DNA glycosylase 1 (hOGG1) was a repair enzyme for removing 8- OH dG from damaged DNA, we hypothesized that hOGG1 mRNA may be used to assess the risk of oxidative damage induced by the exposure of COF. The results from reverse-transcription polymerase chain reaction showed that the hOGG1 mRNA expression was induced by hydrogen peroxide (H2O2) and COF in human lung adenocarcinoma CL-3 cells. To elucidate whether hOGG1 mRNA expression was an exposure biomarker of COF, a cross-sectional study of 238 subjects including 94 professional cooks, 43 housewives, and 101 COF-nonexposed control subjects was conducted. The hOGG1 mRNA expression frequencies of COF-exposed cooks (27 of 94, 28.7%) and housewives (6 of 43, 14%) were significantly higher than those of control subjects (4 of 101, 4%). After adjusting for age, sex, and smoking and drinking status, the odds risks (ORs) of housewives versus control and cooks versus control were 3.94 (95% confidence interval [CI] = 0.95-16.62) and 10.12 (95% CI = 2.83-36.15), respectively. These results indicated that hOGG1 may be adequate to act as an exposure biomarker to assess the oxidative DNA damage induced by COF. This also suggests that oxidative stress induced by COF may play a role in lung cancer development among Chinese women.

Favipiravir inhibits acetaminophen sulfate formation but minimally affects systemic pharmacokinetics of acetaminophen

PubMed Central

Zhao, Yanli; Harmatz, Jerold S; Epstein, Carol R; Nakagawa, Yukako; Kurosaki, Chie; Nakamura, Tetsuro; Kadota, Takumi; Giesing, Dennis; Court, Michael H; Greenblatt, David J

2015-01-01

Aims The antiviral agent favipiravir is likely to be co-prescribed with acetaminophen (paracetamol). The present study evaluated the possiblility of a pharmacokinetic interaction between favipiravir and acetaminophen, in vitro and in vivo. Methods The effect of favipivir on the transformation of acetaminophen to its glucuronide and sulfate metabolites was studied using a pooled human hepatic S9 fraction in vitro. The effect of acute and extended adminstration of favipiravir on the pharmacokinetics of acetaminophen and metabolites was evaluated in human volunteers. Results Favipiravir inhibited the in vitro formation of acetaminophen sulfate, but not acetaminophen glucuronide. In human volunteers, both acute (1 day) and extended (6 days) administration of favipiravir slightly but significantly increased (by about 20 %) systemic exposure to acetaminophen (total AUC), whereas Cmax was not significantly changed. AUC for acetaminophen glucuronide was increased by 23 to 35 % above control by favipiravir, while AUC for acetaminophen sulfate was reduced by about 20 % compared to control. Urinary excretion of acetaminophen sulfate was likewise reduced to 44 to 65 % of control values during favipiravir co-administration, while excretion of acetaminophen glucuronide increased to 17 to 32 % above control. Conclusion Favipiravir inhibits acetaminophen sulfate formation in vitro and in vivo. However the increase in systemic exposure to acetaminophen due to favipiravir co-administration, though statistically significant, is small in magnitude and unlikely to be of clinical importance. PMID:25808818

Does low-energy sweetener consumption affect energy intake and body weight? A systematic review, including meta-analyses, of the evidence from human and animal studies

PubMed Central

Rogers, P J; Hogenkamp, P S; de Graaf, C; Higgs, S; Lluch, A; Ness, A R; Penfold, C; Perry, R; Putz, P; Yeomans, M R; Mela, D J

2016-01-01

By reducing energy density, low-energy sweeteners (LES) might be expected to reduce energy intake (EI) and body weight (BW). To assess the totality of the evidence testing the null hypothesis that LES exposure (versus sugars or unsweetened alternatives) has no effect on EI or BW, we conducted a systematic review of relevant studies in animals and humans consuming LES with ad libitum access to food energy. In 62 of 90 animal studies exposure to LES did not affect or decreased BW. Of 28 reporting increased BW, 19 compared LES with glucose exposure using a specific ‘learning' paradigm. Twelve prospective cohort studies in humans reported inconsistent associations between LES use and body mass index (−0.002 kg m−2 per year, 95% confidence interval (CI) −0.009 to 0.005). Meta-analysis of short-term randomized controlled trials (129 comparisons) showed reduced total EI for LES versus sugar-sweetened food or beverage consumption before an ad libitum meal (−94 kcal, 95% CI −122 to −66), with no difference versus water (−2 kcal, 95% CI −30 to 26). This was consistent with EI results from sustained intervention randomized controlled trials (10 comparisons). Meta-analysis of sustained intervention randomized controlled trials (4 weeks to 40 months) showed that consumption of LES versus sugar led to relatively reduced BW (nine comparisons; −1.35 kg, 95% CI –2.28 to −0.42), and a similar relative reduction in BW versus water (three comparisons; −1.24 kg, 95% CI –2.22 to −0.26). Most animal studies did not mimic LES consumption by humans, and reverse causation may influence the results of prospective cohort studies. The preponderance of evidence from all human randomized controlled trials indicates that LES do not increase EI or BW, whether compared with caloric or non-caloric (for example, water) control conditions. Overall, the balance of evidence indicates that use of LES in place of sugar, in children and adults, leads to reduced EI and BW, and possibly also when compared with water. PMID:26365102

Leptospira Exposure and Gardeners: A Case-Control Seroprevalence Study

PubMed Central

Alvarado-Esquivel, Cosme; Hernandez-Tinoco, Jesus; Sanchez-Anguiano, Luis Francisco; Ramos-Nevarez, Agar; Cerrillo-Soto, Sandra Margarita; Guido-Arreola, Carlos Alberto

2016-01-01

Background Leptospira can be found in soil. However, it is unclear whether occupational exposure to soil may represent a risk for Leptospira infection in humans. Therefore, we sought to determine the association of Leptospira IgG seroprevalence with the occupation of gardener, and to determine the epidemiological characteristics of gardeners associated with Leptospira exposure. Methods We performed a case-control study in 168 gardeners and 168 age- and gender-matched control subjects without gardening occupation in Durango City, Mexico. The seroprevalence of anti-Leptospira IgG antibodies in cases and controls was determined using an enzyme immunoassay. Bivariate and multivariate analyses were used to assess the association of Leptospira exposure and the characteristics of the gardeners. Results Anti-Leptospira IgG antibodies were found in 10 (6%) of 168 gardeners and in 15 (8.9%) of 168 control subjects (odds ratio (OR): 0.64; 95% confidence interval (CI): 0.28 - 1.48; P = 0.40). Multivariate analysis showed that Leptospira seropositivity was positively associated with female gender (OR: 5.82; 95% CI: 1.11 - 30.46; P = 0.03), and negatively associated with eating while working (OR: 0.21; 95% CI: 0.05 - 0.87; P = 0.03). In addition, multivariate analysis showed that high anti-Leptospira levels were associated with consumption of boar meat (OR: 28.00; 95% CI: 1.20 - 648.80; P = 0.03). Conclusions This is the first case-control study of Leptospira exposure in gardeners. Results do not support an association of Leptospira exposure with the occupation of gardener. However, further studies to confirm the lack of this association are needed. The potential role of consumption of boar meat in Leptospira infection deserves further investigation. PMID:26668679

Impairment of the reproductive potential of male fathead minnows by environmentally relevant exposures to 4-nonylphenolf

USGS Publications Warehouse

Schoenfuss, H.L.; Bartell, S.E.; Bistodeau, T.B.; Cediel, R.A.; Grove, K.J.; Zintek, Larry; Lee, K.E.; Barber, L.B.

2008-01-01

The synthetic organic compound 4-nonylphenol (NP) has been detected in many human-impacted surface waters in North America. In this study, we examined the ability of NP to alter reproductive competence in male fathead minnows after a 28 day flow-through exposure in a range of environmentally relevant concentrations bracketing the U.S. Environmental Protection Agency toxicity-based NP chronic exposure criterion of 6.1 ??g NP/L. Exposure to NP at and above the EPA chronic exposure criterion resulted in an induction of plasma vitellogenin (VTG) within 14 days. However, 7 days after the cessation of exposure, VTG concentrations had dropped more than 50% and few males expressed VTG above the detection threshold. All of the morphological endpoints, including gonadosomatic index, hepatosomatic index, secondary sexual characters, and histopathology, were unaltered by all NP treatments. However, when NP-exposed male fish were allowed to compete with control males for access to nest sites and females, most treatments altered the reproductive competence of exposed males. At lower NP concentrations, exposed males out-competed control males, possibly by being primed through the estrogenic NP exposure in a fashion similar to priming by pheromones released from female fathead minnows. At higher NP exposure concentrations, this priming effect was negated by the adverse effects of the exposure and control males out-competed treated males. Results of this study indicate the complexity of endocrine disrupting effects and the need for multiple analysis levels to assess the effects of these compounds on aquatic organisms. ?? 2007 Elsevier B.V. All rights reserved.

Residential Agricultural Pesticide Exposures and Risks of Spontaneous Preterm Birth.

PubMed

Shaw, Gary M; Yang, Wei; Roberts, Eric M; Kegley, Susan E; Stevenson, David K; Carmichael, Suzan L; English, Paul B

2018-01-01

Pesticides exposures are aspects of the human exposome that have not been sufficiently studied for their contribution to risk for preterm birth. We investigated risks of spontaneous preterm birth from potential residential exposures to 543 individual chemicals and 69 physicochemical groupings that were applied in the San Joaquin Valley of California during the study period, 1998-2011. The study population was derived from birth certificate data linked with Office of Statewide Health Planning and Development maternal and infant hospital discharge data. After exclusions, the analytic study base included 197,461 term control births and 27,913 preterm case births. Preterm cases were more narrowly defined as 20-23 weeks (n = 515), 24-27 weeks (n = 1,792), 28-31 weeks (n = 3,098), or 32-36 weeks (n = 22,508). The frequency of any (versus none) pesticide exposure was uniformly lower in each preterm case group relative to the frequency in term controls, irrespective of gestational month of exposure. All odds ratios were below 1.0 for these any versus no exposure comparisons. The majority of odds ratios were below 1.0, many of them statistically precise, for preterm birth and exposures to specific chemical groups or chemicals. This study showed a general lack of increased risk of preterm birth associated with a range of agriculture pesticide exposures near women's residences.

Epidemiology, clinical features and risk factors for human rabies and animal bites during an outbreak of rabies in Maputo and Matola cities, Mozambique, 2014: Implications for public health interventions for rabies control.

PubMed

Salomão, Cristolde; Nacima, Amílcar; Cuamba, Lutero; Gujral, Lorna; Amiel, Olga; Baltazar, Cynthia; Cliff, Julie; Gudo, Eduardo Samo

2017-07-01

In Mozambique, the majority of rabies outbreaks are unreported and data on the epidemiological features of human rabies and animal bites are scarce. An outbreak of human rabies in adjacent Maputo and Matola cities in 2014 prompted us to investigate the epidemiology, clinical features and risk factors of human rabies and animal bites in the two cities. We reviewed cases of human rabies and animal bites from April to July 2014, and carried out a community investigation in July and August in the neighborhoods where cases of human rabies resided. This investigation included collection of clinical, demographic and epidemiological information and a case control study to investigate the risk factors associated with human rabies. Fourteen cases of human rabies were detected in Maputo (n = 10) and Matola (n = 3) cities and neighbouring Boane district (n = 1) between April and August 2014, all of whom had been admitted to hospital. All had a recent history of dog bite. Of the 14 rabid dogs, only one had been immunized. 819 cases of animal bites were registered, of which 64.6% (529/819) were from Maputo City. Dogs were responsible for 97.8% (801/819) of all animal bites, but only 27.0% (126/467) were immunized. Factors significantly associated with human rabies were: age <15 years (p = 0.05), bite by stray dog (p = 0.002), deep wound (p = 0.02), bite in the head (p = 0.001), bite by unimmunized dog (p = 0.01), no use of soap and water (p = 0.001), and no post-exposure prophylaxis (p = 0.01). Implementation of control measures for rabies is poor in Maputo and Matola cities, where cases of human rabies were strongly associated with bites by stray and unvaccinated dogs and irregular implementation of post-exposure measures.

Epidemiology, clinical features and risk factors for human rabies and animal bites during an outbreak of rabies in Maputo and Matola cities, Mozambique, 2014: Implications for public health interventions for rabies control

PubMed Central

Salomão, Cristolde; Nacima, Amílcar; Cuamba, Lutero; Gujral, Lorna; Amiel, Olga; Baltazar, Cynthia; Cliff, Julie

2017-01-01

Background In Mozambique, the majority of rabies outbreaks are unreported and data on the epidemiological features of human rabies and animal bites are scarce. An outbreak of human rabies in adjacent Maputo and Matola cities in 2014 prompted us to investigate the epidemiology, clinical features and risk factors of human rabies and animal bites in the two cities. Methodology/Principal findings We reviewed cases of human rabies and animal bites from April to July 2014, and carried out a community investigation in July and August in the neighborhoods where cases of human rabies resided. This investigation included collection of clinical, demographic and epidemiological information and a case control study to investigate the risk factors associated with human rabies. Fourteen cases of human rabies were detected in Maputo (n = 10) and Matola (n = 3) cities and neighbouring Boane district (n = 1) between April and August 2014, all of whom had been admitted to hospital. All had a recent history of dog bite. Of the 14 rabid dogs, only one had been immunized. 819 cases of animal bites were registered, of which 64.6% (529/819) were from Maputo City. Dogs were responsible for 97.8% (801/819) of all animal bites, but only 27.0% (126/467) were immunized. Factors significantly associated with human rabies were: age <15 years (p = 0.05), bite by stray dog (p = 0.002), deep wound (p = 0.02), bite in the head (p = 0.001), bite by unimmunized dog (p = 0.01), no use of soap and water (p = 0.001), and no post-exposure prophylaxis (p = 0.01). Conclusions/Significance Implementation of control measures for rabies is poor in Maputo and Matola cities, where cases of human rabies were strongly associated with bites by stray and unvaccinated dogs and irregular implementation of post-exposure measures. PMID:28742094

Human responses to bright light of different durations.

PubMed

Chang, Anne-Marie; Santhi, Nayantara; St Hilaire, Melissa; Gronfier, Claude; Bradstreet, Dayna S; Duffy, Jeanne F; Lockley, Steven W; Kronauer, Richard E; Czeisler, Charles A

2012-07-01

Light exposure in the early night induces phase delays of the circadian rhythm in melatonin in humans. Previous studies have investigated the effect of timing, intensity, wavelength, history and pattern of light stimuli on the human circadian timing system. We present results from a study of the duration–response relationship to phase-delaying bright light. Thirty-nine young healthy participants (16 female; 22.18±3.62 years) completed a 9-day inpatient study. Following three baseline days, participants underwent an initial circadian phase assessment procedure in dim light (<3 lux), and were then randomized for exposure to a bright light pulse (∼10,000 lux) of 0.2 h, 1.0 h, 2.5 h or 4.0 h duration during a 4.5 h controlled-posture episode centred in a 16 h wake episode. After another 8 h sleep episode, participants completed a second circadian phase assessment. Phase shifts were calculated from the difference in the clock time of the dim light melatonin onset (DLMO) between the initial and final phase assessments. Exposure to varying durations of bright light reset the circadian pacemaker in a dose-dependent, non-linear manner. Per minute of exposure, the 0.2 h duration was over 5 times more effective at phase delaying the circadian pacemaker (1.07±0.36 h) as compared with the 4.0 h duration (2.65±0.24 h). Acute melatonin suppression and subjective sleepiness also had a dose-dependent response to light exposure duration. These results provide strong evidence for a non-linear resetting response of the human circadian pacemaker to light duration.

Novel tools for blood inflammatory markers detection in monitoring air pollution-induced cardio-respiratory symptoms.

PubMed

Coccini, Teresa; Manzo, Luigi; De Simone, Uliana; Acerbi, Davide; Roda, Elisa

2012-01-01

There is strong epidemiological evidence that air pollution exposure (short- and long-term, i.e. < 24 hr to 3 weeks, and year/s) is related to exacerbation of cardiovascular and respiratory diseases. Data from toxicological and basic science/molecular studies, controlled animal and human exposures and human panel studies have demonstrated several mechanisms by which particle exposure may both trigger acute events as well as prompt the chronic development of cardiovascular diseases. These pollutant-mediated biological mechanisms are supporting the potential use of haematic (inflammation/coagulation/oxidative stress) markers of effects in cardio-respiratory diseases. Various examples from in vitro, in vivo and epidemiological investigations are reported, together with some novel technologies that should provide with new tools for research in these diseases and improve the knowledge about any linkage of local and systemic inflammation and clinical features of these diseases (in particular COPD), including lung function, exacerbations, disease progression, and mortality.

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.

Human health risk assessment related to contaminated land: state of the art.

PubMed

Swartjes, F A

2015-08-01

Exposure of humans to contaminants from contaminated land may result in many types of health damage ranging from relatively innocent symptoms such as skin eruption or nausea, on up to cancer or even death. Human health protection is generally considered as a major protection target. State-of-the-art possibilities and limitations of human health risk assessment tools are described in this paper. Human health risk assessment includes two different activities, i.e. the exposure assessment and the hazard assessment. The combination of these is called the risk characterization, which results in an appraisal of the contaminated land. Exposure assessment covers a smart combination of calculations, using exposure models, and measurements in contact media and body liquids and tissue (biomonitoring). Regarding the time frame represented by exposure estimates, biomonitoring generally relates to exposure history, measurements in contact media to actual exposures, while exposure calculations enable a focus on exposure in future situations. The hazard assessment, which is different for contaminants with or without a threshold for effects, results in a critical exposure value. Good human health risk assessment practice accounts for tiered approaches and multiple lines of evidence. Specific attention is given here to phenomena such as the time factor in human health risk assessment, suitability for the local situation, background exposure, combined exposure and harmonization of human health risk assessment tools.

A comparison of human exposures to fiberglass with those used in a recent rat chronic inhalation study.

PubMed

Hesterberg, T W; Hart, G A

1994-12-01

In a recent rat inhalation study, 2 years of exposure to high concentrations of fiberglass (FG) resulted in no treatment-related fibrosis or thoracic tumors. To determine the relevancy of this study for human risk assessment, it is important to compare the rat experimental exposure levels with those of humans. Data on human exposures were taken from several studies and included FG manufacturing, installation and removal, and ambient air. FG levels in the rat aerosol were 200,000-fold higher than indoor air, > 2000-fold higher than during FG insulation manufacturing, and > 1000-fold higher than FG batt installation. The rat aerosol was 30-fold more concentrated than the highest human exposure (blowing installation of unbound FG). Rat FG lung burden also vastly exceeded that of FG workers, which was not significantly elevated above nonworker levels. The amount of fibers/mg dry lung for the rat after lifetime exposure was > 4000-fold greater than for the FG worker, average exposure 11 years. Aerosol and lung fiber dimensions in the rat study were comparable to those of human exposures. From these comparisons, it can be concluded that the exposure level in the rat inhalation study was sufficiently, if not excessively, high in comparison to human exposures. Increasing the experimental exposure in the rat studies would not serve to mirror human environmental or occupational exposures.

Human health effects of air pollution.

PubMed Central

Folinsbee, L J

1993-01-01

Over the past three or four decades, there have been important advances in the understanding of the actions, exposure-response characteristics, and mechanisms of action of many common air pollutants. A multidisciplinary approach using epidemiology, animal toxicology, and controlled human exposure studies has contributed to the database. This review will emphasize studies of humans but will also draw on findings from the other disciplines. Air pollutants have been shown to cause responses ranging from reversible changes in respiratory symptoms and lung function, changes in airway reactivity and inflammation, structural remodeling of pulmonary airways, and impairment of pulmonary host defenses, to increased respiratory morbidity and mortality. Quantitative and qualitative understanding of the effects of a small group of air pollutants has advanced considerably, but the understanding is by no means complete, and the breadth of effects of all air pollutants is only partially understood. PMID:8354181

Cocaine-mediated impact on HIV infection in humanized BLT mice

PubMed Central

Kim, Sohn G.; Lowe, Emily L.; Dixit, Dhaval; Seyeon Youn, Cindy; Kim, Irene J.; Jung, James B.; Rovner, Robert; Zack, Jerome A.; Vatakis, Dimitrios N.

2015-01-01

Cocaine abuse has been shown to have broad-ranging effects on human immunity. With regards to HIV infection, in vitro studies have shown that cocaine enhances infection of stimulated lymphocytes. Moreover, cohort studies in the pre- and post-HAART era have linked stimulant abuse with increased HIV pathogenesis. The latter data, however, have been undermined by a series of confounding factors underscoring the importance of controlled in vivo models to fully assess the impact of cocaine use and abuse on HIV infection and pathogenesis. Here, we have infected humanized mice with HIV-1 following acute cocaine exposure to assess the impact on infection. Stimulant exposure resulted in increased inflammatory cytokine expression, accelerated HIV infection, while blunting effector function of cytotoxic T lymphocytes. These data demonstrate cocaine’s multifactorial impact on HIV infection that extends beyond high-risk behavior. PMID:26084721

Pediatric and young adult exposure to chemiluminescent glow sticks.

PubMed

Hoffman, Robert J; Nelson, Lewis S; Hoffman, Robert S

2002-09-01

Although chemiluminescent plastic rods, commonly called "glow sticks" or "light sticks," are typically considered to be minimally toxic or nontoxic, published data about exposure to these products are scarce. To test our hypothesis that exposure to chemiluminescent products is unlikely to result in significant morbidity or mortality and to describe factors associated with exposure by reviewing reports to our urban poison control center of human exposure to chemiluminescent products. Pediatric and young adult exposure to chemiluminescent products reported between January 1, 2000, and April 1, 2001, to our poison control center were evaluated with regard to demographic group, type of product involved, circumstances of exposure, symptoms, and management. Reported routes of exposure (n = 118) included ingestion (n = 108), ocular (n = 9), and dermal exposure (n = 1). Only patients exposed to chemiluminescent fluid from a leaking container reported symptoms (n = 27). Symptoms were limited to transient irritation of the exposure site, and no systemic toxicity occurred. All adults (n = 4) inadvertently ruptured or swallowed intact light sticks while at a dance club or dance party. Most exposure and all adult exposure occurred on holidays or weekends. Most incidences of exposure to chemiluminescent products involve asymptomatic ingestion of fluid that leaks from glow sticks or ingestion of an intact glow stick. Symptoms occur after exposure to chemiluminescent fluid and consist of transient irritation at the site of exposure. The clustering of reported exposure on weekends and in dance clubs and parties coupled with a lack of occupational or workplace exposure suggest that recreational use is a major contributory factor. Exposure to chemiluminescent products infrequently resulted in symptoms and the symptoms reported were minor. Exposure to chemiluminescent products as described is unlikely to cause significant morbidity or mortality.

ASSESSING CHILDREN'S EXPOSURES TO PESTICIDES: AN IMPORTANT APPLICATION OF THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION MODEL (SHEDS)

EPA Science Inventory

Accurately quantifying human exposures and doses of various populations to environmental pollutants is critical for the Agency to assess and manage human health risks. For example, the Food Quality Protection Act of 1996 (FQPA) requires EPA to consider aggregate human exposure ...

40 CFR 159.170 - Human epidemiological and exposure studies.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Human epidemiological and exposure... Information § 159.170 Human epidemiological and exposure studies. Information must be submitted which concerns... that a correlation may exist between exposure to a pesticide and observed adverse effects in humans...

40 CFR 159.170 - Human epidemiological and exposure studies.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Human epidemiological and exposure... Information § 159.170 Human epidemiological and exposure studies. Information must be submitted which concerns... that a correlation may exist between exposure to a pesticide and observed adverse effects in humans...

40 CFR 159.170 - Human epidemiological and exposure studies.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Human epidemiological and exposure... Information § 159.170 Human epidemiological and exposure studies. Information must be submitted which concerns... that a correlation may exist between exposure to a pesticide and observed adverse effects in humans...

40 CFR 159.170 - Human epidemiological and exposure studies.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Human epidemiological and exposure... Information § 159.170 Human epidemiological and exposure studies. Information must be submitted which concerns... that a correlation may exist between exposure to a pesticide and observed adverse effects in humans...

Cannabis use is quantitatively associated with nucleus accumbens and amygdala abnormalities in young adult recreational users.

PubMed

Gilman, Jodi M; Kuster, John K; Lee, Sang; Lee, Myung Joo; Kim, Byoung Woo; Makris, Nikos; van der Kouwe, Andre; Blood, Anne J; Breiter, Hans C

2014-04-16

Marijuana is the most commonly used illicit drug in the United States, but little is known about its effects on the human brain, particularly on reward/aversion regions implicated in addiction, such as the nucleus accumbens and amygdala. Animal studies show structural changes in brain regions such as the nucleus accumbens after exposure to Δ9-tetrahydrocannabinol, but less is known about cannabis use and brain morphometry in these regions in humans. We collected high-resolution MRI scans on young adult recreational marijuana users and nonusing controls and conducted three independent analyses of morphometry in these structures: (1) gray matter density using voxel-based morphometry, (2) volume (total brain and regional volumes), and (3) shape (surface morphometry). Gray matter density analyses revealed greater gray matter density in marijuana users than in control participants in the left nucleus accumbens extending to subcallosal cortex, hypothalamus, sublenticular extended amygdala, and left amygdala, even after controlling for age, sex, alcohol use, and cigarette smoking. Trend-level effects were observed for a volume increase in the left nucleus accumbens only. Significant shape differences were detected in the left nucleus accumbens and right amygdala. The left nucleus accumbens showed salient exposure-dependent alterations across all three measures and an altered multimodal relationship across measures in the marijuana group. These data suggest that marijuana exposure, even in young recreational users, is associated with exposure-dependent alterations of the neural matrix of core reward structures and is consistent with animal studies of changes in dendritic arborization.

[Motivation and significance of IARC classification for mobile phone].

PubMed

L'Abbate, N

2011-01-01

In May 2011, the IARC Working Group discussed the possibility that exposure to RF-EMF (radiofrequency electromagnetic fields) have to produce an increased risk for brain tumors and evaluated the available literature on different categories of subjects exposed, including, among others, a Danish cohort study, five case-control studies and the largest multi-center case-control study (INTERPHONE) on the use of mobile phone and brain tumors, including glioma, meningioma and acoustic neuroma. The Working Group also examined a number of studies with objectives related to various mechanisms ofcarcerogenesis. The findings have been reviewed critically and generally assessed as "limited" among users of wireless phones for glioma and acoustic neuroma and "inappropriate" to draw conclusions for other types of tumors. The evidence from occupational and environmental exposures were considered "insufficient" in the same way. Given the limited evidence in humans and in experimental animals, the Working Group has classified a large majority the RF-EMF fields as "possibly carcinogenic to humans" (Group 2B). The Director of IARC has recommended, however,further research in the long-term use of mobile phones and adoption of pragmatic steps to reduce exposure, such as hands-free devices or sms.

The influence of chronic and subacute exposure to lead on the levels of prolactin, leptin, osteopontin, and follistatin in humans.

PubMed

Dobrakowski, M; Kasperczyk, A; Czuba, Z P; Machoń-Grecka, A; Szlacheta, Z; Kasperczyk, S

2017-06-01

This study was designed to determine the levels of prolactin, leptin, osteopontin, and follistatin in workers chronically and subacutely exposed to lead compounds. The examined population consisted of three groups. The first group was composed of 56 male workers who were chronically exposed to lead for 13.38 ± 10.38 years. The second group served as a control group and consisted of 24 male administrative workers, while the third group included 32 male workers exposed to lead for 40 ± 3 days. The levels of leptin, osteopontin, and prolactin were significantly lower in the group of workers chronically exposed to lead than in the control group by 42%, 26%, and 41%, respectively. The levels of follistatin did not differ between those groups. The levels of all measured hormones did not change after a short-term exposure to lead compared to baseline. Chronic lead exposure is associated with significantly decreased level of prolactin, leptin, and osteopontin. Lead-induced changes in the levels of these hormones may disturb many functions of the human body, including the immune response, metabolism, reproduction, and bone turnover.

[Measurement and study report as a part of the control system for human safety and health protection against electromagnetic fields and electromagnetic radiation (0 Hz-300 GHz)].

PubMed

Aniołczyk, Halina

2007-01-01

The National Control System for safety and health protection against electromagnetic fields (EMF) and electromagnetic radiation (EMR) (0 Hz-300 GHz) is constantly analyzed in view of Directive 2004/40/EC. Reports on the effects of investments (at the designing stage or at the stage of looking for their localization) on the environment and measurement and study reports on the objects already existing or being put into operation are important elements of this system. These documents should meet both national and European Union's legislation requirements. The overriding goal of the control system is safety and health protection of humans against electromagnetic fields in the environment and in occupational settings. The author pays a particular attention to provisions made in directives issued by relevant ministers and to Polish standards, which should be documented in measurement and study reports published by the accredited laboratories and relating to the problems of human safety and health protection. Similar requirements are valid for the Reports. Therefore, along with measurement outcomes, the reports should include data on the EMF exposure classification at work-posts and the assessment of occupational risk resulting from EMF exposure or at least thorough data facilitating such a classification.

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

Evaluation of workplace exposure to respirable crystalline silica in Italy.

PubMed

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

2014-10-01

Crystalline silica is a human carcinogen and its use is widespread among construction, mining, foundries, and other manufacturing industries. To evaluate occupational exposure to crystalline silica in Italy. 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. We found 1387 cases of crystalline silica exposure between 1996 and 2012. Exposure was most common in construction work (AM = 0·057 mg/m(3), N = 505), and among miners and quarry workers (AM = 0·048 mg/m(3), N = 238). We estimated that 41 643 workers were at risk of exposure in the selected industrial sectors during the same period. 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.

The effect of D-cycloserine on subliminal cue exposure in spider fearful individuals.

PubMed

Gutner, Cassidy A; Weinberger, Joel; Hofmann, Stefan G

2012-01-01

Research on D-cycloserine (DCS) has demonstrated a significant effect on symptom reduction in human studies that utilized conventional exposure-based approaches. Recent studies have offered promising results for targeting fears through subliminal paradigms. In this double-blind, randomized placebo-controlled study, 45 spider fearful individuals received DCS or placebo pills prior to completing a subliminal cue exposure task to images of spiders. Participants completed self-report questionnaires and a behavioral approach task to a live caged tarantula. After repeated exposure to subliminal spider cues, participants in the DCS group reported a greater reduction in disgust than individuals in the placebo group. No difference was observed in fear ratings. These findings suggest that DCS augments the reduction in disgust in spider fearful subjects after subliminal exposure to spider cues.

RNA interference in a maize pathogen reduces toxin production

USDA-ARS?s Scientific Manuscript database

The fungus Fusarium verticillioides can produce fumonisin mycotoxins in ears under certain environmental conditions. Because fumonisins are unhealthy for humans and livestock, control strategies with nominal risk to the environment are needed to reduce fumonisin exposure. Host-induced gene silencing...

Toluene Inhalation Exposure for 13 Weeks Causes Persistent Changes in Electroretinograms of Long-Evans Rats

EPA Science Inventory

Studies of humans chronically exposed to volatile organic solvents have reported impaired visual functions, including low contrast sensitivity and reduced color discrimination. These reports, however, lacked confirmation from controlled laboratory experiments. To addre...

Biological processes, quantum mechanics and electromagnetic fields: the possibility of device-encapsulated human intention in medical therapies.

PubMed

Kohane, M J; Tiller, W A

2001-06-01

The general hypothesis that quantum mechanics (QM) and thermodynamic concepts relate to biological systems is discussed and applied to the biological influence of: (1) electromagnetic fields (EMFs); and (2) EMFs that have been exposed to human intention. We illustrate our hypothesis with experiments involving four simultaneous treatments: exposure to ambient EMFs in the laboratory environment (C), exposure in a Faraday cage (F) and exposure in a Faraday cage with either: (i) an electronic device (IIED) which had been exposed to a specific human intention (d,j); or (ii) a non-exposed, physically identical, device (d,o). Experimental systems were fitness and energy metabolism in Drosophila melanogaster, in vitro enzyme activity and molecular concentration variability over time. Results indicated that shielding from ambient EMFs via a Faraday cage (F) made a significant difference relative to the unshielded control (C). Further, (d,o) had a significant lowering effect in the shielded environment. Finally, there was a strong 'intention' effect with the IIED (d,j) producing significant and positive effects in comparison to (d,o) in each experimental system. Copyright 2001 Harcourt Publishers Ltd.

Modulation of Human Immune Response by Fungal Biocontrol Agents

PubMed Central

Konstantinovas, Cibele; de Oliveira Mendes, Tiago A.; Vannier-Santos, Marcos A.; Lima-Santos, Jane

2017-01-01

Although the vast majority of biological control agents is generally regarded as safe for humans and environment, the increased exposure of agriculture workers, and consumer population to fungal substances may affect the immune system. Those compounds may be associated with both intense stimulation, resulting in IgE-mediated allergy and immune downmodulation induced by molecules such as cyclosporin A and mycotoxins. This review discusses the potential effects of biocontrol fungal components on human immune responses, possibly associated to infectious, inflammatory diseases, and defective defenses. PMID:28217107

Thrombotic Markers in Metabolic Syndrome Subjects Exposed to Diesel Exhaust

PubMed Central

Carlsten, C.; Kaufman, J. D.; Trenga, C. A.; Allen, J.; Peretz, A.; Sullivan, J. H.

2011-01-01

Traffic-derived particulate matter (PM) is associated with cardiovascular morbidity and mortality, but the mechanism of this association is unclear. Prothrombotic processes have been linked to PM in epidemiological and animal models, but have not been consistently implicated in controlled human models. Diesel exhaust (DE) is a major contributor to PM. We conducted a controlled human exposure of DE in subjects with metabolic syndrome. The study objective was to evaluate DE exposure effects on prothrombotic markers in a population vulnerable to cardiovascular disease. A randomized, crossover, double-blinded design was used: 16 subjects with metabolic syndrome exposed on 3 different days (≥2 wk washout) to DE at 0 (filtered air, FA), 100 μg PM2.5/m3 (DE100) and 200 μg PM2.5/m3 (DE200). We assessed DE-associated changes in D-dimer, von Willebrand factor (VWF), and plasmin activator inhibitor-1 (PAI-1) at 3, 7, and 22 h after exposure initiation. A DE200-attributable decrease (1.17-fold; CI 1.04 to 1.34) in VWF was noted at 7 h. Significant changes did not occur in other primary endpoints. As previously noted with healthy subjects, strong diurnal patterns in PAI-1 were observed. Thus, in a novel study, we were unable to demonstrate a prothrombotic effect of moderate-dose diesel exhaust exposure in a population at risk for cardiovascular disease. PMID:18668408

AN OVERVIEW OF HUMAN EXPOSURE MODELING ACTIVITIES AT THE U.S. EPA'S NATIONAL EXPOSURE RESEARCH LABORATORY

EPA Science Inventory

The computational modeling of human exposure to environmental pollutants is one of the primary activities of the US Environmental Protection Agency (USEPA)'s National Exposure Research Laboratory (NERL). Assessment of human exposures is a critical part of the overall risk assessm...

40 CFR 158.1060 - Post-application exposure-criteria for testing

Code of Federal Regulations, 2012 CFR

2012-07-01

...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Human Exposure § 158.1060 Post-application exposure...) Occupational human post-application exposure to pesticide residues on plants or in soil could occur as the...) Residential human post-application exposure to pesticide residues on plants or in soil could occur. Such uses...

40 CFR 158.1060 - Post-application exposure-criteria for testing

Code of Federal Regulations, 2011 CFR

2011-07-01

...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Human Exposure § 158.1060 Post-application exposure...) Occupational human post-application exposure to pesticide residues on plants or in soil could occur as the...) Residential human post-application exposure to pesticide residues on plants or in soil could occur. Such uses...

40 CFR 158.1060 - Post-application exposure-criteria for testing.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Human Exposure § 158.1060 Post-application exposure...) Occupational human post-application exposure to pesticide residues on plants or in soil could occur as the...) Residential human post-application exposure to pesticide residues on plants or in soil could occur. Such uses...

40 CFR 158.1060 - Post-application exposure-criteria for testing

Code of Federal Regulations, 2010 CFR

2010-07-01

...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Human Exposure § 158.1060 Post-application exposure...) Occupational human post-application exposure to pesticide residues on plants or in soil could occur as the...) Residential human post-application exposure to pesticide residues on plants or in soil could occur. Such uses...

40 CFR 158.1060 - Post-application exposure-criteria for testing.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Human Exposure § 158.1060 Post-application exposure...) Occupational human post-application exposure to pesticide residues on plants or in soil could occur as the...) Residential human post-application exposure to pesticide residues on plants or in soil could occur. Such uses...

Early Postnatal Manganese Exposure Causes Lasting Impairment of Selective and Focused Attention and Arousal Regulation in Adult Rats.

PubMed

Beaudin, Stephane A; Strupp, Barbara J; Strawderman, Myla; Smith, Donald R

2017-02-01

Studies in children and adolescents have associated early developmental manganese (Mn) exposure with inattention, impulsivity, hyperactivity, and oppositional behaviors, but causal inferences are precluded by the correlational nature of the data and generally limited control for potential confounders. To determine whether early postnatal oral Mn exposure causes lasting attentional and impulse control deficits in adulthood, and whether continued lifelong Mn exposure exacerbates these effects, using a rat model of environmental Mn exposure. Neonates were exposed orally to 0, 25 or 50 mg Mn/kg/day during early postnatal life (PND 1-21) or throughout life from PND 1 until the end of the study. In adulthood, the animals were tested on a series of learning and attention tasks using the five-choice serial reaction time task. Early postnatal Mn exposure caused lasting attentional dysfunction due to impairments in attentional preparedness, selective attention, and arousal regulation, whereas associative ability (learning) and impulse control were spared. The presence and severity of these deficits varied with the dose and duration of Mn exposure. This study is the first to show that developmental Mn exposure can cause lasting impairments in focused and selective attention and arousal regulation, and to identify the specific nature of the impairments. Given the importance of attention and arousal regulation in cognitive functioning, these findings substantiate concerns about the adverse effects of developmental Mn exposure in humans. Citation: Beaudin SA, Strupp BJ, Strawderman M, Smith DR. 2017. Early postnatal manganese exposure causes lasting impairment of selective and focused attention and arousal regulation in adult rats. Environ Health Perspect 125:230-237; http://dx.doi.org/10.1289/EHP258.

Early Postnatal Manganese Exposure Causes Lasting Impairment of Selective and Focused Attention and Arousal Regulation in Adult Rats

PubMed Central

Beaudin, Stephane A.; Strupp, Barbara J.; Strawderman, Myla; Smith, Donald R.

2016-01-01

Background: Studies in children and adolescents have associated early developmental manganese (Mn) exposure with inattention, impulsivity, hyperactivity, and oppositional behaviors, but causal inferences are precluded by the correlational nature of the data and generally limited control for potential confounders. Objectives: To determine whether early postnatal oral Mn exposure causes lasting attentional and impulse control deficits in adulthood, and whether continued lifelong Mn exposure exacerbates these effects, using a rat model of environmental Mn exposure. Methods: Neonates were exposed orally to 0, 25 or 50 mg Mn/kg/day during early postnatal life (PND 1–21) or throughout life from PND 1 until the end of the study. In adulthood, the animals were tested on a series of learning and attention tasks using the five-choice serial reaction time task. Results: Early postnatal Mn exposure caused lasting attentional dysfunction due to impairments in attentional preparedness, selective attention, and arousal regulation, whereas associative ability (learning) and impulse control were spared. The presence and severity of these deficits varied with the dose and duration of Mn exposure. Conclusions: This study is the first to show that developmental Mn exposure can cause lasting impairments in focused and selective attention and arousal regulation, and to identify the specific nature of the impairments. Given the importance of attention and arousal regulation in cognitive functioning, these findings substantiate concerns about the adverse effects of developmental Mn exposure in humans. Citation: Beaudin SA, Strupp BJ, Strawderman M, Smith DR. 2017. Early postnatal manganese exposure causes lasting impairment of selective and focused attention and arousal regulation in adult rats. Environ Health Perspect 125:230–237; http://dx.doi.org/10.1289/EHP258 PMID:27384154

Sharp Injury and Exposure to Blood and Body Fluids among Health Care Workers in Health Care Centers of Eastern Ethiopia.

PubMed

Alemayehu, T; Worku, A; Assefa, N

2016-07-01

Health care workers are facing certain occupational hazards because of sharp injury and exposure to human blood and body fluids as a result of handling wastes. Though much attention is paid for the protection of these workers, the number of exposures and injuries do not show a sign of decline from time to time. To examine the occurrence of sharp injury and exposure to blood and body fluids in health care workers in health care centers in Ethiopia. In a case-control study, a randomly selected sample of 65 health facilities with 391 cases and 429 controls were studied. Data were collected through a self-administered questionnaire. Detailed analysis of exposure among the health care workers was done by logistic regression analysis with generalized estimating equations model to control correlation effects of responses within the cluster of health facilities. The number of health care workers who got sharp injury was 217 (26.5%). 296 (36.1%) had exposure to blood and body fluids. Working at Harari region (adjusted OR 0.44, 95% CI 0.26 to 0.75) and East Hararghea (adjusted OR 0.61, 95% CI 0.40 to 0.94), being male (adjusted OR 0.56, 95% CI 0.44 to 0.91), and a being nurse (adjusted OR 0.188, 95% CI 0.06 to 0.63) were independent risk factors of the exposure. Regardless of the anticipated low self-reporting for exposure status, the number of health care workers reported having sharp injury and exposure to blood and body fluids was high. Such high exposures indicate that health care workers are at high risk of acquiring blood-borne viral infections such as hepatitis B, hepatitis C, and HIV.

Phenotypic and transcriptional response to selection for alcohol sensitivity in Drosophila melanogaster

PubMed Central

Morozova, Tatiana V; Anholt, Robert RH; Mackay, Trudy FC

2007-01-01

Background Alcoholism is a complex disorder determined by interactions between genetic and environmental risk factors. Drosophila represents a powerful model system to dissect the genetic architecture of alcohol sensitivity, as large numbers of flies can readily be reared in defined genetic backgrounds and under controlled environmental conditions. Furthermore, flies exposed to ethanol undergo physiological and behavioral changes that resemble human alcohol intoxication, including loss of postural control, sedation, and development of tolerance. Results We performed artificial selection for alcohol sensitivity for 35 generations and created duplicate selection lines that are either highly sensitive or resistant to ethanol exposure along with unselected control lines. We used whole genome expression analysis to identify 1,678 probe sets with different expression levels between the divergent lines, pooled across replicates, at a false discovery rate of q < 0.001. We assessed to what extent genes with altered transcriptional regulation might be causally associated with ethanol sensitivity by measuring alcohol sensitivity of 37 co-isogenic P-element insertional mutations in 35 candidate genes, and found that 32 of these mutants differed in sensitivity to ethanol exposure from their co-isogenic controls. Furthermore, 23 of these novel genes have human orthologues. Conclusion Combining whole genome expression profiling with selection for genetically divergent lines is an effective approach for identifying candidate genes that affect complex traits, such as alcohol sensitivity. Because of evolutionary conservation of function, it is likely that human orthologues of genes affecting alcohol sensitivity in Drosophila may contribute to alcohol-associated phenotypes in humans. PMID:17973985

Radiation Effect on Human Tissue

NASA Technical Reports Server (NTRS)

Richmond, Robert C.; Cruz, Angela; Bors, Karen; Curreri, Peter A. (Technical Monitor)

2002-01-01

Predicting the occurrence of human cancer following exposure of an epidemiologic population to any agent causing genetic damage is a difficult task. To an approximation, this is because the uncertainty of uniform exposure to the damaging agent, and the uncertainty of uniform processing of that damage within a complex set of biological variables, degrade the confidence of predicting the delayed expression of cancer as a relatively rare event within clinically normal individuals. This situation begs the need for alternate controlled experimental models that are predictive for the development of human cancer following exposures to agents causing genetic damage. Such models historically have not been of substantial proven value. It is more recently encouraging, however, that developments in molecular and cell biology have led to an expanded knowledge of human carcinogenesis, and of molecular markers associated with that process. It is therefore appropriate to consider new laboratory models developed to accomodate that expanded knowledge in order to assess the cancer risks associated with exposures to genotoxic agents. When ionizing radiation of space is the genotoxic agent, then a series of additional considerations for human cancer risk assessment must also be applied. These include the dose of radiation absorbed by tissue at different locations in the body, the quality of the absorbed radiation, the rate at which absorbed dose accumulates in tissue, the way in which absorbed dose is measured and calculated, and the alterations in incident radiation caused by shielding materials. It is clear that human cancer risk assessment for damage caused by ionizing radiation is a multidisciplinary responsibility, and that within this responsibility no single discipline can hold disproportionate sway if a risk assessment model of radiation-induced human cancer is to be developed that has proven value. Biomolecular and cellular markers from the work reported here are considered for use in assessing human cancer risk related to exposure to space radiation. This potential use must be integrated within the specified multidisciplinary context in order to create a new tool of molecular epidemiology that can hopefully then realistically assess this cancer risk.

Could cryopreserved human semen samples be stored at -80°C?

PubMed Central

Vaz, Carlos R; Lamim, Tamara; Salvador, Rafael A; Batschauer, Anna P B; Amaral, Vera Lucia L; Til, David

2018-01-01

Objective To evaluate storage time effects in cryopreserved human semen samples, kept in the freezer at a controlled temperature of -80°C, on sperm viability after thawing. Methods We used 20 semen samples. Each sample was cryopreserved in 10 fingers, which were divided into five groups: one group was kept in cryogenic canisters throughout the experiment(control), and four groups were kept in a VIP Ultra Low MDF-U76V- PE freezer, with the temperature set at -80°C, for 24, 48, 72 and 96 hours, respectively. After the exposure time, the samples were stored in cryogenic canisters after being thawed. The analyzed parameters were: motility, vitality and mitochondrial activity. Results After thawing, we noticed decreased sperm motility, vitality and mitochondrial activity, when comparing the tested groups with the control group, as well as a progressive reduction in the analyzed parameters between the times evaluated. Conclusions Cryopreservation of semen samples at -80°C is potentially harmful to sperm viability, causing damage when submitted to longer exposure times. PMID:29338138

Report on computation of repetitive hyperbaric-hypobaric decompression tables

NASA Technical Reports Server (NTRS)

Edel, P. O.

1975-01-01

The tables were constructed specifically for NASA's simulated weightlessness training program; they provide for 8 depth ranges covering depths from 7 to 47 FSW, with exposure times of 15 to 360 minutes. These tables were based up on an 8 compartment model using tissue half-time values of 5 to 360 minutes and Workmanline M-values for control of the decompression obligation resulting from hyperbaric exposures. Supersaturation ratios of 1.55:1 to 2:1 were used for control of ascents to altitude following such repetitive dives. Adequacy of the method and the resultant tables were determined in light of past experience with decompression involving hyperbaric-hypobaric interfaces in human exposures. Using these criteria, the method showed conformity with empirically determined values. In areas where a discrepancy existed, the tables would err in the direction of safety.

Acute Meteorite Dust Exposure and Pulmonary Inflammation - Implications for Human Space Exploration

NASA Technical Reports Server (NTRS)

Harrington, A. D.; McCubbin, F. M.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

2017-01-01

The previous manned missions to the Moon represent milestones of human ingenuity, perseverance, and intellectual curiosity. However, one of the major ongoing concerns is the array of hazards associated with lunar surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness [1-3]" (Figure 1). It was further reported that the allergic response to the dust worsened with each exposure [4]. The lack of gravity exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles [1]. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern [5]. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. Studies on the lunar highland regolith indicate that the dust is not only respirable but also reactive [2, 6-9], and previous studies concluded that it is moderately toxic; generating a greater response than titanium oxide but a lower response than quartz [6]. The presence of reactive oxygen species (ROS) on the surface of the dust has been implicated. However, there is actually little data related to physicochemical characteristics of particulates and pulmonary toxicity, especially as it relates to celestial dust exposure. As a direct response to this deficit, the present study evaluates the role of a particulate's innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. This highly interdisciplinary study evaluates the relative toxicity of six meteorite samples representing either basalt or regolith breccia on the surfaces of the Moon, Mars, and Asteroid 4Vesta (Table 1); three potential candidates for future human exploration or colonization. Terrestrial mid-ocean ridge basalt (MORB) is also used for comparison as a control sample.

Pulmonary Inflammatory Responses To Acute Meteorite Dust Exposures - Implications For Human Space Exploration

NASA Technical Reports Server (NTRS)

Harrington, A. D.; McCubbin, F. M.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

2017-01-01

The previous manned missions to the Moon represent milestones of human ingenuity, perseverance, and intellectual curiosity. However, one of the major ongoing concerns is the array of hazards associated with lunar surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness" (Figure 1). It was further reported that the allergic response to the dust worsened with each exposure. The lack of gravity exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. Studies on the lunar highland regolith indicate that the dust is not only respirable but also reactive, and previous studies concluded that it is moderately toxic; generating a greater response than titanium oxide but a lower response than quartz. The presence of reactive oxygen species (ROS) on the surface of the dust has been implicated. However, there is actually little data related to physicochemical characteristics of particulates and pulmonary toxicity, especially as it relates to celestial dust exposure. As a direct response to this deficit, the present study evaluates the role of a particulate's innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. This highly interdisciplinary study evaluates the relative toxicity of six meteorite samples representing either basalt or regolith breccia on the surfaces of the Moon, Mars, and Asteroid 4Vesta; three potential candidates for future human exploration or colonization. Terrestrial mid-ocean ridge basalt (MORB) is also used for comparison as a control sample.

Current status of Mycobacterium avium subspecies paratuberculosis infection in animals & humans in India: What needs to be done?

PubMed

Singh, Ajay Vir; Chauhan, Devendra Singh; Singh, Shoor Vir; Kumar, Vijay; Singh, Abhinendra; Yadav, Anjali; Yadav, Virendra Singh

2016-11-01

Mycobacterium avium subspecies paratuberculosis (MAP) has emerged as a major health problem for domestic livestock and human beings. Reduced per animal productivity of domestic livestock seriously impacts the economics of dairy farming globally. High to very high bioload of MAP in domestic livestock and also in the human population has been reported from north India. Presence of live MAP bacilli in commercial supplies of raw and pasteurized milk and milk products indicates its public health significance. MAP is not inactivated during pasteurization, therefore, entering into human food chain daily. Recovery of MAP from patients with inflammatory bowel disease or Crohn's disease and animal healthcare workers suffering with chronic gastrointestinal problems indicate a close association of MAP with a number of chronic and other diseases affecting human health. Higher bioload of MAP in the animals increases the risk of exposure to the human population with MAP. This review summarizes the current status of MAP infection in animals as well as in human beings and also highlights the prospects of effective management and control of disease in animals to reduce the risk of exposure to human population.

DNA methylation levels and long-term trihalomethane exposure in drinking water: an epigenome-wide association study

PubMed Central

Salas, Lucas A; Bustamante, Mariona; Gonzalez, Juan R; Gracia-Lavedan, Esther; Moreno, Victor; Kogevinas, Manolis; Villanueva, Cristina M

2015-01-01

Trihalomethanes (THM) are undesired disinfection byproducts (DBPs) formed during water treatment. Mice exposed to DBPs showed global DNA hypomethylation and c-myc and c-jun gene-specific hypomethylation, while evidence of epigenetic effects in humans is scarce. We explored the association between lifetime THM exposure and DNA methylation through an epigenome-wide association study. We selected 138 population-based controls from a case-control study of colorectal cancer conducted in Barcelona, Spain, exposed to average lifetime THM levels ≤85 μg/L vs. >85 μg/L (N = 68 and N = 70, respectively). Mean age of participants was 70 years, and 54% were male. Average lifetime THM level in the exposure groups was 64 and 130 µg/L, respectively. DNA was extracted from whole blood and was bisulphite converted to measure DNA methylation levels using the Illumina HumanMethylation450 BeadChip. Data preprocessing was performed using RnBeads. Methylation was compared between exposure groups using empirical Bayes moderated linear regression for CpG sites and Gaussian kernel for CpG regions. ConsensusPathDB was used for gene set enrichment. Statistically significant differences in methylation between exposure groups was found in 140 CpG sites and 30 gene-related regions, after false discovery rate <0.05 and adjustment for age, sex, methylation first principal component, and blood cell proportion. The annotated genes were localized to several cancer pathways. Among them, 29 CpGs had methylation levels associated with THM levels (|Δβ|≥0.05) located in 11 genes associated with cancer in other studies. Our results suggest that THM exposure may affect DNA methylation in genes related to tumors, including colorectal and bladder cancers. Future confirmation studies are required. PMID:26039576

DDT Exposure in Utero and Breast Cancer

PubMed Central

La Merrill, Michele; Krigbaum, Nickilou Y.; Yeh, Gregory; Park, June-Soo; Zimmermann, Lauren; Cirillo, Piera M.

2015-01-01

Context: Currently no direct evidence links in utero dichlorodiphenyltrichloroethane (DDT) exposure to human breast cancer. However, in utero exposure to another xenoestrogen, diethylstilbestrol, predicts an increased breast cancer risk. If this finding extends to DDT, it could have far-reaching consequences. Many women were heavily exposed in utero during widespread DDT use in the 1960s. They are now reaching the age of heightened breast cancer risk. DDT exposure persists and use continues in Africa and Asia without clear knowledge of the consequences for the next generation. Hypothesis: In utero exposure to DDT is associated with an increased risk of breast cancer. Design: This was a case-control study nested in a prospective 54-year follow-up of 9300 daughters in the Child Health and Development Studies pregnancy cohort (n = 118 breast cancer cases, diagnosed by age 52 y and 354 controls matched on birth year). Setting and Participants: Kaiser Foundation Health Plan members who received obstetric care in Alameda County, California, from 1959 to 1967, and their adult daughters participated in the study. Main Outcome Measure: Daughters' breast cancer diagnosed by age 52 years as of 2012 was measured. Results: Maternal o,p′-DDT predicted daughters' breast cancer (odds ratio fourth quartile vs first = 3.7, 95% confidence interval 1.5–9.0). Mothers' lipids, weight, race, age, and breast cancer history did not explain the findings. Conclusions: This prospective human study links measured DDT exposure in utero to risk of breast cancer. Experimental studies are essential to confirm results and discover causal mechanisms. Findings support classification of DDT as an endocrine disruptor, a predictor of breast cancer, and a marker of high risk. PMID:26079774

Occupational Styrene Exposure on Auditory Function Among Adults: A Systematic Review of Selected Workers.

PubMed

Pleban, Francis T; Oketope, Olutosin; Shrestha, Laxmi

2017-12-01

A review study was conducted to examine the adverse effects of styrene, styrene mixtures, or styrene and/or styrene mixtures and noise on the auditory system in humans employed in occupational settings. The search included peer-reviewed articles published in English language involving human volunteers spanning a 25-year period (1990-2015). Studies included peer review journals, case-control studies, and case reports. Animal studies were excluded. An initial search identified 40 studies. After screening for inclusion, 13 studies were retrieved for full journal detail examination and review. As a whole, the results range from no to mild associations between styrene exposure and auditory dysfunction, noting relatively small sample sizes. However, four studies investigating styrene with other organic solvent mixtures and noise suggested combined exposures to both styrene organic solvent mixtures may be more ototoxic than exposure to noise alone. There is little literature examining the effect of styrene on auditory functioning in humans. Nonetheless, findings suggest public health professionals and policy makers should be made aware of the future research needs pertaining to hearing impairment and ototoxicity from styrene. It is recommended that chronic styrene-exposed individuals be routinely evaluated with a comprehensive audiological test battery to detect early signs of auditory dysfunction.

Managing Formaldehyde indoor pollution in anatomy pathology departments.

PubMed

d'Ettorre, Gabriele; Criscuolo, Mario; Mazzotta, Mauro

2017-01-01

Nearly eleven years have passed since the International Agency for Research on Cancer classified Formaldehyde (FA) as a known human carcinogen (group 1), yet the safety of anatomy pathology workers who are currently exposed to FA is still a matter of concern. The purpose of this study was to evaluate the literature to discover which topics have been focused on and what the latest developments are in managing FA indoor pollution in anatomy pathology departments. which topics have been focused on and what the latest developments in managing FA indoor pollution in anatomy pathology departments. For the purpose of this review, we searched for publications in PubMed and Web of Science using selected keywords. The articles were reviewed and categorized into one or more of the following three categories based on subject matter: exposure levels exposure controls and alternatives. Our search resulted in a total of 31 publications that matched our inclusion criteria. The topics discussed, in order of frequency (from highest to lowest), were: "exposure controls", "exposure levels" and "alternatives". The most frequently suggested intervention was to improve local exhaust ventilation systems to minimize FA levels in gross anatomy laboratories. We found a lack of evidence-based improvement interventions that aimed to control exposure to FA. According to this finding, and pending a valid chemical substitute for FA, we suggest the need for more in-depth studies targeting measures to minimize exposures to FA in pathology departments.

[Epidemiology of human infection with avian influenza A(H7N9) virus in China, 2013-2017].

PubMed

Han, D D; Han, C X; Li, L Y; Wang, M; Yang, J H; Li, M

2018-01-10

Objective: To understand the epidemiological characteristics of human infection with avian influenza A (H7N9) virus in China, and provide evidence for the prevention and control of human infection with H7N9 virus. Methods: The published incidence data of human infection with H7N9 virus in China from March 2013 to April 2017 were collected. Excel 2007 software was used to perform the analysis. The characteristics of distribution of the disease, exposure history, cluster of the disease were described. Results: By the end of April 2017, a total of 1 416 cases of human infection with H7N9 virus were confirmed in China, including 559 deaths, the case fatality rate was 39.5%. In 2016, the case number was lowest (127 cases), with the highest fatality rate (57.5%). The first three provinces with high case numbers were Zhejiang, Guangdong and Jiangsu. The median age of the cases was 55 years and the male to female ratio was 2.3∶1. Up to 66% of cases had clear live poultry exposure history before illness onset, 31% of cases had unknown exposure history and only 3% of the cases had no live poultry exposure history. There were 35 household clusters (5 in 2013, 9 in 2014, 6 in 2015, 5 in 2016, 10 in 2017), which involved 72 cases, accounting for 5% of the total cases. Conclusions: The epidemic of human infection with H7N9 virus in China during 2013-2017 had obvious seasonality and spatial distribution. There was limited family clustering. Infection cases were mostly related to poultry contact.

Evidence of carcinogenicity in humans of water-soluble nickel salts

PubMed Central

2010-01-01

Background Increased risks of nasal cancer and lung cancer in nickel refiners have been investigated scientifically and discussed since they were detected in the 1930s. Nickel compounds are considered to be the main cause of the cancer excess. Parts of the nickel producing industry and their consultants oppose the classification of water-soluble nickel salts as human carcinogens, and argue that the risk in exposed workers should be ascribed to other occupational exposures and smoking. Discussion Respiratory cancer risks in Welsh, Finnish, and Norwegian nickel refiners add to the evidence of carcinogenicity of water-soluble nickel. In Norwegian refiners, the first epidemiological study in 1973 identified high risks of lung cancer and nasal cancer among long-term electrolysis workers. Risk analyses based on exposure estimates developed in the 1980s supported the view that water-soluble nickel compounds were central in the development of cancer. Recently, new exposure estimates were worked out for the same cohort based on personal monitoring of total nickel and chemical determination of four forms of nickel. Additional data have been collected on life-time smoking habits, and on exposure to arsenic, asbestos, sulphuric acid mists, cobalt, and occupational lung carcinogens outside the refinery. After adjustment for these potential confounding exposures in case-control analyses, the risk pattern added to the evidence of an important role of water-soluble nickel compounds as causes of lung cancer. These Norwegian cancer studies rely on national Cancer Registry data, considered close to complete from 1953 onwards; and on National Population Register data continuously updated with mortality and emigration. Canadian mortality studies--perceived to offer the strongest support to the industry position not to recognise carcinogenicity of water-soluble nickel--appear to suffer from limitations in follow-up time, loss to follow-up, absence of risk analysis with individual exposure estimates, no confounder control, and a likely underestimation of cancer mortality. Conclusions Rejection to recognise water-soluble nickel as a human carcinogen seems to contradict material epidemiological evidence that demonstrates a strong association between water-soluble nickel compounds and risks of lung cancer and nasal cancer. Independent international scientific bodies have classified nickel compounds as carcinogenic to humans, inclusive of water-soluble nickel. PMID:20377901

Post-exposure therapy with recombinant human BuChE following percutaneous VX challenge in guinea-pigs

PubMed Central

Mumford, Helen; Troyer, John K.

2011-01-01

Poisoning by nerve agents via the percutaneous (p.c.) route is an issue because the slow absorption of agent could result in poisoning which outlasts the protection provided by conventional pharmacological therapy. The bioscavenger approach is based on the concept of binding nerve agent in the bloodstream, thus preventing nerve agent from reaching the target tissues and inhibiting acetylcholinesterase activity. One bioscavenger that has been extensively studied is human butyrylcholinesterase (huBuChE). Protexia® is a pegylated form of recombinant huBuChE. We used a guinea-pig model of p.c. nerve agent poisoning, using an implanted telemetry system to collect physiological data. Guinea-pigs were poisoned with the nerve agent VX (0.74 mg/kg) (~2.5×LD50). Two hours following VX exposure, Protexia (72 mg/kg) or saline control was administered intramuscularly. All guinea-pigs treated with Protexia (n=8) survived, compared to no survivors in a saline-treated control group (n=8). Survival following VX and Protexia treatment was associated with minimal incapacitation and observable signs of poisoning, and the mitigation or prevention of the detrimental physiological changes (e.g. seizure, bradycardia and hypothermia) observed in control animals. The opportunity for post-exposure treatment may have utility in both civilian and military scenarios, and this is a promising indication for the use of a bioscavenger. PMID:21620937

Timing of light exposure affects mood and brain circuits

PubMed Central

Bedrosian, T A; Nelson, R J

2017-01-01

Temporal organization of physiology is critical for human health. In the past, humans experienced predictable periods of daily light and dark driven by the solar day, which allowed for entrainment of intrinsic circadian rhythms to the environmental light–dark cycles. Since the adoption of electric light, however, pervasive exposure to nighttime lighting has blurred the boundaries of day and night, making it more difficult to synchronize biological processes. Many systems are under circadian control, including sleep–wake behavior, hormone secretion, cellular function and gene expression. Circadian disruption by nighttime light perturbs those processes and is associated with increasing incidence of certain cancers, metabolic dysfunction and mood disorders. This review focuses on the role of artificial light at night in mood regulation, including mechanisms through which aberrant light exposure affects the brain. Converging evidence suggests that circadian disruption alters the function of brain regions involved in emotion and mood regulation. This occurs through direct neural input from the clock or indirect effects, including altered neuroplasticity, neurotransmission and clock gene expression. Recently, the aberrant light exposure has been recognized for its health effects. This review summarizes the evidence linking aberrant light exposure to mood. PMID:28140399

Maternal exposure to a mixture of persistent organic pollutants (POPs) affects testis histology, epididymal sperm count and induces sperm DNA fragmentation in mice.

PubMed

Khezri, Abdolrahman; Lindeman, Birgitte; Krogenæs, Anette K; Berntsen, Hanne F; Zimmer, Karin E; Ropstad, Erik

2017-08-15

Persistent organic pollutants (POPs) are widespread throughout the environment and some are suspected to induce reproductive toxicity. As animals and humans are exposed to complex mixtures of POPs, it is reasonable to assess how such mixtures could interact with the reproductive system. Our aim is to investigate how maternal exposure to a mixture of 29 different persistent organic pollutants, formulated to mimic the relative POP levels in the food basket of the Scandinavian population, could alter reproductive endpoints. Female mice were exposed via feed from weaning, during pregnancy and lactation in 3 exposure groups (control (C), low (L) and high (H)). Testicular morphometric endpoints, epididymal sperm concentration and sperm DNA integrity were assessed in adult male offspring. We found that the number of tubules, proportion of tubule compartments and epididymal sperm concentration significantly decreased in both POP exposed groups. Epididymal sperm from both POP exposed groups showed increased DNA fragmentation. It is concluded that maternal exposure to a defined POP mixture relevant to human exposure can affect testicular development, sperm production and sperm chromatin integrity. Copyright © 2017 Elsevier Inc. All rights reserved.

Diesel Engine Exhaust: Basis for Occupational Exposure Limit Value.

PubMed

Taxell, Piia; Santonen, Tiina

2017-08-01

Diesel engines are widely used in transport and power supply, making occupational exposure to diesel exhaust common. Both human and animal studies associate exposure to diesel exhaust with inflammatory lung effects, cardiovascular effects, and an increased risk of lung cancer. The International Agency for Research on Cancer has evaluated diesel exhaust as carcinogenic to humans. Yet national or regional limit values for controlling occupational exposure to diesel exhaust are rare. In recent decades, stricter emission regulations have led to diesel technologies evolving significantly, resulting in changes in exhaust emissions and composition. These changes are also expected to influence the health effects of diesel exhaust. This review provides an overview of the current knowledge on the health effects of diesel exhaust and the influence of new diesel technologies on the health risk. It discusses the relevant exposure indicators and perspectives for setting occupational exposure limit values for diesel exhaust, and outlines directions for future research. The review is based on a collaborative evaluation report by the Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals and the Dutch Expert Committee on Occupational Safety. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

[Effects on serum myelin proteins of n-hexane exposure].

PubMed

Yi, Juan; Zhou, Wei; He, Jia-xi; Liu, Qing-jun; Huang, Xian-qing

2011-02-01

Exploring the effects of n-hexane on expression of serum myelin proteins in occupational exposure workers, and finding the early biomarker of n-hexane exposure. In the study, 373 subjects were recruited, 269 exposure workers (work experience of more than1 year) and 104 non-exposure workers were selected. Firstly examined the level of urinary 2,5-hexanedione in the two groups, based on urinary 2,5-hexanedione biological limit value (4 mg/L), the exposed group was divided into high-exposed group and low-exposed group. And then collected blood samples and extracted serum. Human peripheral myelin protein zero (P0) antibody (IgG, IgM) and human peripheral myelin protein two (P2) antibody (IgG, IgM) analysis was performed according to ELISA kit. The concentration of urinary 2,5-hexanedione in the exposed group was (3.10 ± 1.35) mg/L. The level of P0 antibody (IgG, IgM) and P2 antibody (IgG, IgM) in the high-exposed group and low-exposed group were both higher than that in the controls (P < 0.01). P0 antibody and P2 antibody could be used as the early biomarkers of n-hexane exposure, which not only evaluate the occupational hazards in the early, but also provide the policy maker with scientific evidence.

Effects of m-xylene on human equilibrium measured with a quantitative method.

PubMed

Savolainen, K; Linnavuo, M

1979-04-01

Swaying during normal upright posture in 17 young males and the effects of m-xylene exposure on the body sway of six of the 17 has been studied by a quantitative Romberg test, conducted with an equipment consisting of a strain gauge transducer platform and of an electronic unit. The exposures were conducted in a dynamic exposure chamber. The sway of the 17 subjects was larger when their eyes were closed than when they were open (P less than 0.001) indicating the importance of vision in the control of body balance. Exposure to a time-weighted average (TWA) concentration of 100 p.p.m. (4.1 mumol/l) of xylene with 200 p.p.m. (8.2 mumol/l) peaks had no observable effect on the body balance of the six subjects. Exposure to a TWA concentration of 200 p.p.m. of xylene with 400 p.p.m. (16.4 mumol/l) peaks--the corresponding mean concentration of xylene in venous blood being 29.1 +/- 3.2 mumol/l--clearly impaired the body balance of the six subjects. The impairment was most pronounced with the eyes closed (P = 0.016). The results suggest that human equilibrium is rather sensitive to effects of exposure to xylene.

Carbohydrate-electrolyte drinks exhibit risks for human enamel surface loss

PubMed Central

Passos, Vanara Florêncio; Lima, Juliana Paiva Marques; Santiago, Sérgio Lima; Rodrigues, Lidiany Karla Azevedo

2016-01-01

Objectives The aim of this investigation was to give insights into the impact of carbohydrate-electrolyte drinks on the likely capacity of enamel surface dissolution and the influence of human saliva exposure as a biological protective factor. Materials and Methods The pH, titratable acidity (TA) to pH 7.0, and buffer capacity (β) of common beverages ingested by patients under physical activity were analyzed. Then, we randomly distributed 50 specimens of human enamel into 5 groups. Processed and natural coconut water served as controls for testing three carbohydrate-electrolyte drinks. In all specimens, we measured surface microhardness (Knoop hardness numbers) and enamel loss (profilometry, µm) for baseline and after simulated intake cycling exposure model. We also prepared areas of specimens to be exposed to human saliva overnight prior to the simulated intake cycling exposure. The cycles were performed by alternated immersions in beverages and artificial saliva. ANOVA two-way and Tukey HDS tests were used. Results The range of pH, TA, and β were 2.85 - 4.81, 8.33 - 46.66 mM/L and 3.48 - 10.25 mM/L × pH, respectively. The highest capacity of enamel surface dissolution was found for commercially available sports drinks for all variables. Single time human saliva exposure failed to significantly promote protective effect for the acidic attack of beverages. Conclusions In this study, carbohydrate-electrolyte drinks usually consumed during endurance training may have a greater capacity of dissolution of enamel surface depending on their physicochemical proprieties associated with pH and titratable acidity. PMID:27847745

Factors that contribute to biomarker responses in humans including a study in individuals taking Vitamin C supplementation.

PubMed

Anderson, D

2001-09-01

It is possible in many situations to identify humans exposed to potentially toxic materials in the workplace and in the environment. As in most human studies, there tends to be a high degree of interindividual variability in response to chemical insults. Some non-exposed control individuals exhibit as high a level of damage as some exposed individuals and some of these have levels of damage as low as many of the controls. Thus, it is only the mean values of the groups that can substantiate an exposure-related problem; the data on an individual basis are still of limited use. While human lymphocytes remain the most popular cell type for monitoring purposes, sperm, buccal, nasal, epithelial and placental cells are also used. However, for interpretation of responses, the issue of confounding factors must be addressed. There are endogenous confounding factors, such as age, gender, and genetic make-up and exogenous ones, including lifestyle habits (smoking, drinking, etc.) There are biomarkers of exposure, effect/response and susceptibility and the last may be influenced by the genotype and polymorphism genes existing in a population. From our own studies, confounding effects on cytogenetic damage and ras oncoproteins will be considered in relation to workers exposed to vinyl chloride and petroleum emissions and to volunteers taking Vitamin C supplementation. Smoking history, exposure and duration of employment affected the worker studies. For petroleum emissions, so did gender and season of exposure. For the non-smoking volunteer Vitamin C supplementation study, cholesterol levels, plasma Vitamin C levels, lipid peroxidation products and DNA damage in the Comet assay were also measured. Gender affected differences in Vitamin C levels, antioxidant capacity and the number of chromosome aberrations induced by bleomycin challenge in vitro. The results were the same for both high and low cholesterol subjects. The relationship between biomarkers and the various factors which affect them is complex. Sometimes the variables are not completely independent of each other.

Pathogen and rodenticide exposure in American badgers (Taxidea taxus) in California.

PubMed

Quinn, Jessica H; Girard, Yvette A; Gilardi, Kirsten; Hernandez, Yvette; Poppenga, Robert; Chomel, Bruno B; Foley, Janet E; Johnson, Christine K

2012-04-01

Urban and agricultural land use may increase the risk of disease transmission among wildlife, domestic animals, and humans as we share ever-shrinking and fragmented habitat. American badgers (Taxidae taxus), a species of special concern in California, USA, live in proximity to urban development and often share habitat with livestock and small peridomestic mammals. As such, they may be susceptible to pathogens commonly transmitted at this interface and to anticoagulant rodenticides used to control nuisance wildlife on agricultural lands. We evaluated free-ranging badgers in California for exposure to pathogens and anticoagulant rodenticides that pose a risk to wildlife, domestic animals, or public health. We found serologic evidence of badger exposure to Francisella tularensis, Toxoplasma gondii, Anaplasma phagocytophilum, canine distemper virus, and three Bartonella species: B. henselae, B. clarridgeiae, and B. vinsonii subsp. berkhoffii. Badger tissues contained anticoagulant rodenticides brodifacoum and bromadiolone, commonly used to control periurban rodent pests. These data provide a preliminary investigation of pathogen and toxicant exposure in the wild badger population.

Prenatal alcohol exposure affects vasculature development in the neonatal brain.

PubMed

Jégou, Sylvie; El Ghazi, Faiza; de Lendeu, Pamela Kwetieu; Marret, Stéphane; Laudenbach, Vincent; Uguen, Arnaud; Marcorelles, Pascale; Roy, Vincent; Laquerrière, Annie; Gonzalez, Bruno José

2012-12-01

In humans, antenatal alcohol exposure elicits various developmental disorders, in particular in the brain. Numerous studies focus on the deleterious effects of alcohol on neural cells. Although recent studies suggest that alcohol can affect angiogenesis in adults, the impact of prenatal alcohol exposure on brain microvasculature remains poorly understood. We used a mouse model to investigate effects of prenatal alcohol exposure on the cortical microvascular network in vivo and ex vivo and the action of alcohol, glutamate, and vascular endothelial growth factor A (VEGF) on activity, plasticity, and survival of microvessels. We used quantitative reverse transcriptase polymerase chain reaction, Western blot, immunohistochemistry, calcimetry, and videomicroscopy. We characterized the effect of prenatal alcohol exposure on the cortical microvascular network in human controls and fetal alcohol syndrome (FAS)/partial FAS (pFAS) patients at different developmental stages. In mice, prenatal alcohol exposure induced a reduction of cortical vascular density, loss of the radial orientation of microvessels, and altered expression of VEGF receptors. Time-lapse experiments performed on brain slices revealed that ethanol inhibited glutamate-induced calcium mobilization in endothelial cells, affected plasticity, and promoted death of microvessels. These effects were prevented by VEGF. In humans, we evidenced a stage-dependent alteration of the vascular network in the cortices of fetuses with pFAS/FAS. Whereas no modification was observed from gestational week 20 (WG20) to WG22, the radial organization of cortical microvessels was clearly altered in pFAS/FAS patients from WG30 to WG38. Prenatal alcohol exposure affects cortical angiogenesis both in mice and in pFAS/FAS patients, suggesting that vascular defects contribute to alcohol-induced brain abnormalities. Copyright © 2012 American Neurological Association.

Effects of Ionizing Radiation on Human Adipose Derived Mesenchymal Stem Cells and their Differentiation towards the Osteoblastic Lineage

NASA Astrophysics Data System (ADS)

Konda, Bikash; Baumstark-Khan, Christa; Hellweg, Christine; Reitz, Guenther; Lau, Patrick

Radiation exposure and musculoskeletal disuse are among the major challenges during space missions. Astronauts face the problem to lose bone calcium due to uncoupling of bone formation and resorption. Bone forming osteoblasts can be derived from the undifferentiated mesenchymal stem cell compartment (MSC). In this study, the ability of human adipose tissue derived stem cells (ATSC) to differentiate into the osteoblastic lineage was examined after radiation exposure in presence of medium supplementation with osteogenic additives (ß-glycerophosphate, ascorbic acid and dexamethasone). The SAOS-2 cell line (human osteosarcoma cell line) was used as control for osteoblastic differentiation. Changes in cellular morphology, cell cycle progression, as well as cellular radiation sensitivity were characterized after ionizing radiation exposure with X-rays and heavy ions (Ti). Rapidly proliferating SAOS-2 cells are less radiation-sensitive than slowly proliferating ATSC cells after X-ray (CFA: dose effect curves show D0 values of 1 Gy and 0.75 Gy for SAOS-2 and ATSC, respectively) exposure. Heavy ion (Ti) exposure resulted in a greater extent of cells accumulating in the G2/M phase of the cell cycle in a dose-dependent manner when compared to X-ray exposure. Differentiation of cells towards the osteoblastic lineage was quantified by hydroxyapatite (HA) deposition using Lonza OsteoImageTM mineralization assay. The deposition of HA after X- and Ti-irradiation for highly proliferating SAOS-2 cells showed a dose-dependent time delay while slowly proliferating ATSC showed no effect from radiation exposure. More detailed investigation is required to reveal the radiation dependent mechanism of bone loss in astronauts.

Effects of RF-EMF Exposure from GSM Mobile Phones on Proliferation Rate of Human Adipose-derived Stem Cells: An In-vitro Study

PubMed Central

Shahbazi-Gahrouei, D.; Hashemi-Beni, B.; Ahmadi, Z.

2016-01-01

Background: As the use of mobile phones is increasing, public concern about the harmful effects of radiation emitted by these devices is also growing. In addition, protection questions and biological effects are among growing concerns which have remained largely unanswered. Stem cells are useful models to assess the effects of radiofrequency electromagnetic fields (RF-EMF) on other cell lines. Stem cells are undifferentiated biological cells that can differentiate into specialized cells. Adipose tissue represents an abundant and accessible source of adult stem cells. The aim of this study is to investigate the effects of GSM 900 MHz on growth and proliferation of mesenchymal stem cells derived from adipose tissue within the specific distance and intensity. Materials and Methods: ADSCs were exposed to GSM mobile phones 900 MHz with intensity of 354.6 µW/cm2 square waves (217 Hz pulse frequency, 50% duty cycle), during different exposure times ranging from 6 to 21 min/day for 5 days at 20 cm distance from the antenna. MTT assay was used to determine the growth and metabolism of cells and trypan blue test was also done for cell viability. Statistical analyses were carried out using analysis of one way ANOVA. P<0.05 was considered to be statistically significant. Results: The proliferation rates of human ADSCs in all exposure groups were significantly lower than control groups (P<0.05) except in the group of 6 minutes/day which did not show any significant difference with control groups. Conclusion: The results show that 900 MHz RF signal radiation from antenna can reduce cell viability and proliferation rates of human ADSCs regarding the duration of exposure. PMID:28144594

The Human Exposure Model (HEM): A Tool to Support Rapid Assessment of Human Health Impacts from Near-Field Consumer Product Exposures

EPA Science Inventory

The US EPA is developing an open and publically available software program called the Human Exposure Model (HEM) to provide near-field exposure information for Life Cycle Impact Assessments (LCIAs). Historically, LCIAs have often omitted impacts from near-field sources of exposur...

Mobile phone base station-emitted radiation does not induce phosphorylation of Hsp27.

PubMed

Hirose, H; Sakuma, N; Kaji, N; Nakayama, K; Inoue, K; Sekijima, M; Nojima, T; Miyakoshi, J

2007-02-01

An in vitro study focusing on the effects of low-level radiofrequency (RF) fields from mobile radio base stations employing the International Mobile Telecommunication 2000 (IMT-2000) cellular system was conducted to test the hypothesis that modulated RF fields act to induce phosphorylation and overexpression of heat shock protein hsp27. First, we evaluated the responses of human cells to microwave exposure at a specific absorption rate (SAR) of 80 mW/kg, which corresponds to the limit of the average whole-body SAR for general public exposure defined as a basic restriction in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. Second, we investigated whether continuous wave (CW) and Wideband Code Division Multiple Access (W-CDMA) modulated signal RF fields at 2.1425 GHz induced activation or gene expression of hsp27 and other heat shock proteins (hsps). Human glioblastoma A172 cells were exposed to W-CDMA radiation at SARs of 80 and 800 mW/kg for 2-48 h, and CW radiation at 80 mW/kg for 24 h. Human IMR-90 fibroblasts from fetal lungs were exposed to W-CDMA at 80 and 800 mW/kg for 2 or 28 h, and CW at 80 mW/kg for 28 h. Under the RF field exposure conditions described above, no significant differences in the expression levels of phosphorylated hsp27 at serine 82 (hsp27[pS82]) were observed between the test groups exposed to W-CDMA or CW signal and the sham-exposed negative controls, as evaluated immediately after the exposure periods by bead-based multiplex assays. Moreover, no noticeable differences in the gene expression of hsps were observed between the test groups and the negative controls by DNA Chip analysis. Our results confirm that exposure to low-level RF field up to 800 mW/kg does not induce phosphorylation of hsp27 or expression of hsp gene family.

Effect of Conditioned Stimulus Exposure during Slow Wave Sleep on Fear Memory Extinction in Humans

PubMed Central

He, Jia; Sun, Hong-Qiang; Li, Su-Xia; Zhang, Wei-Hua; Shi, Jie; Ai, Si-Zhi; Li, Yun; Li, Xiao-Jun; Tang, Xiang-Dong; Lu, Lin

2015-01-01

Study Objectives: Repeated exposure to a neutral conditioned stimulus (CS) in the absence of a noxious unconditioned stimulus (US) elicits fear memory extinction. The aim of the current study was to investigate the effects of mild tone exposure (CS) during slow wave sleep (SWS) on fear memory extinction in humans. Design: The healthy volunteers underwent an auditory fear conditioning paradigm on the experimental night, during which tones served as the CS, and a mild shock served as the US. They were then randomly assigned to four groups. Three groups were exposed to the CS for 3 or 10 min or an irrelevant tone (control stimulus, CtrS) for 10 min during SWS. The fourth group served as controls and was not subjected to any interventions. All of the subjects completed a memory test 4 h after SWS-rich stage to evaluate the effect on fear extinction. Moreover, we conducted similar experiments using an independent group of subjects during the daytime to test whether the memory extinction effect was specific to the sleep condition. Participants: Ninety-six healthy volunteers (44 males) aged 18–28 y. Measurements and Results: Participants exhibited undisturbed sleep during 2 consecutive nights, as assessed by sleep variables (all P > 0.05) from polysomnographic recordings and power spectral analysis. Participants who were re-exposed to the 10 min CS either during SWS and wakefulness exhibited attenuated fear responses (wake-10 min CS, P < 0.05; SWS-10 min CS, P < 0.01). Conclusions: Conditioned stimulus re-exposure during slow wave sleep promoted fear memory extinction without altering sleep profiles. Citation: He J, Sun HQ, Li SX, Zhang WH, Shi J, Ai SZ, Li Y, Li XJ, Tang XD, Lu L. Effect of conditioned stimulus exposure during slow wave sleep on fear memory extinction in humans. SLEEP 2015;38(3):423–431. PMID:25348121

Urinary Virome Perturbations in Kidney Transplantation.

PubMed

Sigdel, Tara K; Mercer, Neil; Nandoe, Sharvin; Nicora, Carrie D; Burnum-Johnson, Kristin; Qian, Wei-Jun; Sarwal, Minnie M

2018-01-01

The human microbiome is important for health and plays a role in essential metabolic functions and protection from certain pathogens. Conversely, dysbiosis of the microbiome is seen in the context of various diseases. Recent studies have highlighted that a complex microbial community containing hundreds of bacteria colonizes the healthy urinary tract, but little is known about the human urinary viruses in health and disease. To evaluate the human urinary virome in the context of kidney transplantation (tx), variations in the composition of the urinary virome were evaluated in urine samples from normal healthy volunteers as well as patients with kidney disease after they had undergone kidney tx. Liquid chromatography-mass spectrometry/mass spectrometry analysis was undertaken on a selected cohort of 142 kidney tx patients and normal healthy controls, from a larger biobank of 770 kidney biopsy matched urine samples. In addition to analysis of normal healthy control urine, the cohort of kidney tx patients had biopsy confirmed phenotype classification, coincident with the urine sample analyzed, of stable grafts (STA), acute rejection, BK virus nephritis, and chronic allograft nephropathy. We identified 37 unique viruses, 29 of which are being identified for the first time in human urine samples. The composition of the human urinary virome differs in health and kidney injury, and the distribution of viral proteins in the urinary tract may be further impacted by IS exposure, diet and environmental, dietary, or cutaneous exposure to various insecticides and pesticides.

The Use of Biomonitoring Data in Exposure and Human Health Risk Assessments

PubMed Central

Albertini, Richard; Bird, Michael; Doerrer, Nancy; Needham, Larry; Robison, Steven; Sheldon, Linda; Zenick, Harold

2006-01-01

Biomonitoring uses analytic methods that permit the accurate measurement of low levels of environmental chemicals in human tissues. However, depending on the intended use, biomonitoring, like all exposure tools, may not be a stand-alone exposure assessment tool for some of its environmental public health uses. Although biomonitoring data demonstrate that many environmental chemicals are absorbed in human tissues, uncertainty exists regarding if and at what concentrations many of these chemicals cause adverse health outcomes. Moreover, without exposure pathway information, it is difficult to relate biomonitoring results to sources and routes of exposure and develop effective health risk management strategies. In September 2004, the Health and Environmental Sciences Institute, U.S. Environmental Protection Agency, Centers for Disease Control and Prevention, Agency for Toxic Substances and Disease Registry, and International Council of Chemical Associations co-sponsored the International Biomonitoring Workshop, which explored the processes and information needed for placing biomonitoring data into perspective for risk assessment purposes, with special emphasis on integrating biomarker measurements of exposure, internal dose, and potential health outcome. Scientists from international governments, academia, and industry recommended criteria for applying biomonitoring data for various uses. Six case studies, which are part of this mini-monograph, were examined: inorganic arsenic, methyl eugenol, organophosphorus pesticides, perfluorooctanesulfonate, phthalates, and polybrominated diphenyl ethers. Based on the workshop and follow-up discussions, this overview article summarizes lessons learned, identifies data gaps, outlines research needs, and offers guidance for designing and conducting biomonitoring studies, as well as interpreting biomonitoring data in the context of risk assessment and risk management. PMID:17107864

Reanalysis of the DEMS Nested Case-Control Study of Lung Cancer and Diesel Exhaust: Suitability for Quantitative Risk Assessment

PubMed Central

Crump, Kenny S; Van Landingham, Cynthia; Moolgavkar, Suresh H; McClellan, Roger

2015-01-01

The International Agency for Research on Cancer (IARC) in 2012 upgraded its hazard characterization of diesel engine exhaust (DEE) to “carcinogenic to humans.” The Diesel Exhaust in Miners Study (DEMS) cohort and nested case-control studies of lung cancer mortality in eight U.S. nonmetal mines were influential in IARC’s determination. We conducted a reanalysis of the DEMS case-control data to evaluate its suitability for quantitative risk assessment (QRA). Our reanalysis used conditional logistic regression and adjusted for cigarette smoking in a manner similar to the original DEMS analysis. However, we included additional estimates of DEE exposure and adjustment for radon exposure. In addition to applying three DEE exposure estimates developed by DEMS, we applied six alternative estimates. Without adjusting for radon, our results were similar to those in the original DEMS analysis: all but one of the nine DEE exposure estimates showed evidence of an association between DEE exposure and lung cancer mortality, with trend slopes differing only by about a factor of two. When exposure to radon was adjusted, the evidence for a DEE effect was greatly diminished, but was still present in some analyses that utilized the three original DEMS DEE exposure estimates. A DEE effect was not observed when the six alternative DEE exposure estimates were utilized and radon was adjusted. No consistent evidence of a DEE effect was found among miners who worked only underground. This article highlights some issues that should be addressed in any use of the DEMS data in developing a QRA for DEE. PMID:25857246

Monitoring wastewater for assessing community health: Sewage Chemical-Information Mining (SCIM)

EPA Science Inventory

Timely assessment of the aggregate health of small-area human populations is essential for guiding the optimal investment of resources needed for preventing, avoiding, controlling, or mitigating exposure risks, as well as for maintaining or promoting health. Seeking those interve...

EPA Technology Available for Licensing: Portable Device to Concentrate Water Samples for Microorganism Analysis

EPA Pesticide Factsheets

Using a computer controlled system, this ultrafiltration device automates the process of concentrating a water sample and can be operated in the field. The system was also designed to reduce human exposure to potentially contaminated water.

The Blacklegged Tick, Ixodes scapularis: An Increasing Public Health Concern.

PubMed

Eisen, Rebecca J; Eisen, Lars

2018-04-01

In the United States, the blacklegged tick, Ixodes scapularis, is a vector of seven human pathogens, including those causing Lyme disease, anaplasmosis, babesiosis, Borrelia miyamotoi disease, Powassan virus disease, and ehrlichiosis associated with Ehrlichia muris eauclarensis. In addition to an accelerated rate of discovery of I. scapularis-borne pathogens over the past two decades, the geographic range of the tick, and incidence and range of I. scapularis-borne disease cases, have increased. Despite knowledge of when and where humans are most at risk of exposure to infected ticks, control of I. scapularis-borne diseases remains a challenge. Human vaccines are not available, and we lack solid evidence for other prevention and control methods to reduce human disease. The way forward is discussed. Published by Elsevier Ltd.

OVERVIEW OF THE U.S. EPA NERL'S HUMAN EXPOSURE MODELING

EPA Science Inventory

Computational modeling of human exposure to environmental pollutants is one of the primary activities of the US Environmental Protection Agency's National Exposure Research Laboratory (NERL). Assessment of human exposures is a critical part of the overall risk assessment para...

Developing a Salivary Antibody Multiplex Immunoassay to ...

EPA Pesticide Factsheets

The etiology and impacts of human exposure to environmental pathogens are of major concern worldwide and, thus, the ability to assess exposure and infections using cost effective, high-throughput approaches would be indispensable. The principal objective of this work is to develop an immunoassay capable of measuring the presence of antibodies in human saliva to multiple pathogens simultaneously. Saliva is particularly attractive in this application because it is noninvasive, cheaper and easier to collect than serum. Antigens from environmental pathogens were coupled to carboxylated microspheres (beads) and used to measure antibodies in very small volumes of human saliva samples using the Luminex xMAP solution-phase assay. Beads were coupled to antigens from Campylobacter jejuni, Helicobacter pylori, Toxoplasma gondii, noroviruses (G I.1 and G II.4) and hepatitis A virus. To ensure that the antigens were sufficiently coupled to the beads, coupling was confirmed using species-specific, animal-derived primary detection antibodies, followed by incubation with biotinylated anti-species secondary detection antibodies and streptavidin-R-phycoerythrin reporter (SAPE). As a control to measure non-specific binding, one bead set was treated identically to the others except it was not coupled to any antigen. The antigen coupled and control beads were then incubated with prospectively-collected human saliva samples, analyzed on a Luminex 100 platform, and the presence

Environmental health risks of toxic waste site exposures--an epidemiological perspective.

PubMed

von Schirnding, Y E; Ehrlich, R I

1992-06-06

A general account is given of the problems of assessing the impact of human exposure to toxic waste sites, including the identification of truly exposed populations and of exposure pathways. Epidemiological studies of populations at risk are briefly reviewed and methodological problems summarised. These include the use of relatively weak study designs, inadequate exposure assessment and recall biases associated with symptom reporting among anxious residents living in the vicinity of waste sites. In South Africa, health risks associated with exposure to toxic waste sites need to be viewed in the context of current community health concerns, competing causes of disease and ill-health, and the relative lack of knowledge about environmental contamination and associated health effects. A nonspecific deterioration of health and well-being is more likely to result from waste site exposures than is overt clinical disease. Socially acceptable policies and controls may have to be based on criteria other than demonstrable ill-health. Detailed inventories and registries of the nature of disposed materials need to be maintained, sites of poorly controlled disposal in the past identified and selective environmental monitoring conducted. Epidemiological studies may be justified in situations where exposures well in excess of acceptable norms are demonstrated. An integrated national waste management policy for the country is urgently needed.

Redox proteomic evaluation of oxidative modification and recovery in a 3D reconstituted human skin tissue model exposed to UVB.

PubMed

Dyer, J M; Haines, S R; Thomas, A; Wang, W; Walls, R J; Clerens, S; Harland, D P

2017-04-01

Exposure to UV in humans resulting in sunburn triggers a complex series of events that are a mix of immediate and delayed damage mediation and healing. While studies on the effects of UV exposure on DNA damage and repair have been reported, changes in the oxidative modification of skin proteins are poorly understood at the molecular level, despite the important role played by structural proteins in skin tissue, and the effect of the integrity of these proteins on skin appearance and health. Proteomic molecular mapping of oxidation was here applied to try to enhance understanding of skin damage and recovery from oxidative damage and UVB exposure. A redox proteomic-based approach was applied to evaluating skin protein modification when exposed to varying doses of UVB after initial oxidative stress, via tracking changes in protein oxidation during the healing process in vitro using a full-thickness reconstituted human skin tissue model. Bioassays and structural evaluation confirmed that our cultured skin tissues underwent a normal physiological response to UVB exposure. A set of potential skin marker peptides was generated, for use in tracking skin protein oxidative modification. Exposure to UVB after thermal oxidative stress was found to result in higher levels of skin protein oxidation than a non-irradiated control for up to seven days after exposure. Recovery of the skin proteins from oxidative stress, as assessed by the overall protein oxidation levels, was found to be impaired by UVB exposure. Oxidative modification was largely observed in skin structural proteins. Exposure of skin proteins to UVB exacerbates oxidative damage to structural skin proteins, with higher exposure levels leading to increasingly impaired recovery from this damage. This has potential implications for the functional performance of the proteins and inter-related skin health and cosmetic appearance. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Experience with speech sounds is not necessary for cue trading by budgerigars (Melopsittacus undulatus)

PubMed Central

Flaherty, Mary; Dent, Micheal L.; Sawusch, James R.

2017-01-01

The influence of experience with human speech sounds on speech perception in budgerigars, vocal mimics whose speech exposure can be tightly controlled in a laboratory setting, was measured. Budgerigars were divided into groups that differed in auditory exposure and then tested on a cue-trading identification paradigm with synthetic speech. Phonetic cue trading is a perceptual phenomenon observed when changes on one cue dimension are offset by changes in another cue dimension while still maintaining the same phonetic percept. The current study examined whether budgerigars would trade the cues of voice onset time (VOT) and the first formant onset frequency when identifying syllable initial stop consonants and if this would be influenced by exposure to speech sounds. There were a total of four different exposure groups: No speech exposure (completely isolated), Passive speech exposure (regular exposure to human speech), and two Speech-trained groups. After the exposure period, all budgerigars were tested for phonetic cue trading using operant conditioning procedures. Birds were trained to peck keys in response to different synthetic speech sounds that began with “d” or “t” and varied in VOT and frequency of the first formant at voicing onset. Once training performance criteria were met, budgerigars were presented with the entire intermediate series, including ambiguous sounds. Responses on these trials were used to determine which speech cues were used, if a trading relation between VOT and the onset frequency of the first formant was present, and whether speech exposure had an influence on perception. Cue trading was found in all birds and these results were largely similar to those of a group of humans. Results indicated that prior speech experience was not a requirement for cue trading by budgerigars. The results are consistent with theories that explain phonetic cue trading in terms of a rich auditory encoding of the speech signal. PMID:28562597

Experience with speech sounds is not necessary for cue trading by budgerigars (Melopsittacus undulatus).

PubMed

Flaherty, Mary; Dent, Micheal L; Sawusch, James R

2017-01-01

The influence of experience with human speech sounds on speech perception in budgerigars, vocal mimics whose speech exposure can be tightly controlled in a laboratory setting, was measured. Budgerigars were divided into groups that differed in auditory exposure and then tested on a cue-trading identification paradigm with synthetic speech. Phonetic cue trading is a perceptual phenomenon observed when changes on one cue dimension are offset by changes in another cue dimension while still maintaining the same phonetic percept. The current study examined whether budgerigars would trade the cues of voice onset time (VOT) and the first formant onset frequency when identifying syllable initial stop consonants and if this would be influenced by exposure to speech sounds. There were a total of four different exposure groups: No speech exposure (completely isolated), Passive speech exposure (regular exposure to human speech), and two Speech-trained groups. After the exposure period, all budgerigars were tested for phonetic cue trading using operant conditioning procedures. Birds were trained to peck keys in response to different synthetic speech sounds that began with "d" or "t" and varied in VOT and frequency of the first formant at voicing onset. Once training performance criteria were met, budgerigars were presented with the entire intermediate series, including ambiguous sounds. Responses on these trials were used to determine which speech cues were used, if a trading relation between VOT and the onset frequency of the first formant was present, and whether speech exposure had an influence on perception. Cue trading was found in all birds and these results were largely similar to those of a group of humans. Results indicated that prior speech experience was not a requirement for cue trading by budgerigars. The results are consistent with theories that explain phonetic cue trading in terms of a rich auditory encoding of the speech signal.

Viral infections in pregnancy: advice for healthcare workers.

PubMed

Chin, T L; MacGowan, A P; Jacobson, S K; Donati, M

2014-05-01

Healthcare workers (HCWs) have the potential for increased exposure to infectious disease resulting from the provision of patient care. Pregnancy can confer specific problems in some infections for the mother and her unborn child. To discuss the viral infections encountered in the UK that constitute a particular risk to the pregnant HCW: human immunodeficiency virus, hepatitis B virus, hepatitis C virus, varicella-zoster virus, herpes simplex virus, human parvovirus B19, cytomegalovirus, rubella, measles, enteroviruses, mumps and influenza. Evidence for nosocomial transmission, clinical aspects specific to pregnancy, and recommendations to protect the pregnant HCW at work are included. Medline, EMBASE and Pubmed were searched using a list of keywords specific to each viral infection, including 'nosocomial', 'occupational' and 'healthcare workers'. References from the bibliographies of articles identified were reviewed for relevant material. The evidence for increased risk in the healthcare setting for many of these infections, outside of outbreaks, is weak, possibly because of the application of standard protective infection control measures or because risk of community exposure is greater. The pregnant HCW should be advised on protective behaviour in both settings. Potential interventions include vaccination and reducing the likelihood of exposure through universal precautions, infection control and redeployment. Protection of the pregnant HCW is the responsibility of the individual, antenatal care provider and employer, and is made possible through awareness of the risks and potential interventions both before and after exposure. If exposure occurs or if the HCW develops an infective illness, urgent specialist advice is required. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

The circadian clock controls sunburn apoptosis and erythema in mouse skin.

PubMed

Gaddameedhi, Shobhan; Selby, Christopher P; Kemp, Michael G; Ye, Rui; Sancar, Aziz

2015-04-01

Epidemiological studies of humans and experimental studies with mouse models suggest that sunburn resulting from exposure to excessive UV light and damage to DNA confers an increased risk for melanoma and non-melanoma skin cancer. Previous reports have shown that both nucleotide excision repair, which is the sole pathway in humans for removing UV photoproducts, and DNA replication are regulated by the circadian clock in mouse skin. Furthermore, the timing of UV exposure during the circadian cycle has been shown to affect skin carcinogenesis in mice. Because sunburn and skin cancer are causally related, we investigated UV-induced sunburn apoptosis and erythema in mouse skin as a function of circadian time. Interestingly, we observed that sunburn apoptosis, inflammatory cytokine induction, and erythema were maximal following an acute early-morning exposure to UV and minimal following an afternoon exposure. Early-morning exposure to UV also produced maximal activation of ataxia telangiectasia mutated and Rad3-related (Atr)-mediated DNA damage checkpoint signaling, including activation of the tumor suppressor p53, which is known to control the process of sunburn apoptosis. These data provide early evidence that the circadian clock has an important role in the erythemal response in UV-irradiated skin. The early morning is when DNA repair is at a minimum, and thus the acute responses likely are associated with unrepaired DNA damage. The prior report that mice are more susceptible to skin cancer induction following chronic irradiation in the AM, when p53 levels are maximally induced, is discussed in terms of the mutational inactivation of p53 during chronic irradiation.

The Circadian Clock Controls Sunburn Apoptosis and Erythema in Mouse Skin

PubMed Central

Gaddameedhi, Shobhan; Selby, Christopher P.; Kemp, Michael G.; Ye, Rui; Sancar, Aziz

2014-01-01

Epidemiological studies of humans and experimental studies with mouse models suggest that sunburn resulting from exposure to excessive UV light and damage to DNA confers an increased risk for melanoma and non-melanoma skin cancer. Previous reports have shown that both nucleotide excision repair, which is the sole pathway in humans for removing UV photoproducts, and DNA replication, are regulated by the circadian clock in mouse skin. Furthermore, the timing of UV exposure during the circadian cycle has been shown to affect skin carcinogenesis in mice. Because sunburn and skin cancer are causally related, we investigated UV-induced sunburn apoptosis and erythema in mouse skin as a function of circadian time. Interestingly, we observed that sunburn apoptosis, inflammatory cytokine induction, and erythema were maximal following an acute early morning exposure to UV and minimal following an afternoon exposure. Early morning exposure to UV also produced maximal activation of Atr-mediated DNA damage checkpoint signaling including activation of the tumor suppressor p53, which is known to control the process of sunburn apoptosis. To our knowledge these data provide the first evidence that the circadian clock plays an important role in the erythemal response in UV-irradiated skin. The early morning is when DNA repair is at a minimum, thus the acute responses likely are associated with unrepaired DNA damage. The prior report that mice are more susceptible to skin cancer induction following chronic irradiation in the AM, when p53 levels are maximally induced, is discussed in terms of the mutational inactivation of p53 during chronic irradiation. PMID:25431853

Identification and determination of disinfection byproducts in chlorine-containing household cleansing products.

PubMed

Shin, Ho-Sang; Lim, Hyun-Hee

2017-05-01

Seven halogenated volatile organic compounds (HVOCs) and two haloacetic acids were detected and quantified in 15 household products, including sodium hypochlorite, by gas chromatography-mass spectrometry (GC-MS). Chloroform was detected in a range of 0.2-30.2 mg kg -1 in all products, and carbon tetrachloride was observed in 13 samples in a range of 0.05-352 mg kg -1 . Dichloroacetic acid and trichloroacetic acid were also detected up to 94 and 146 mg kg -1 in household products. The estimated human exposures of chloroform, carbon tetrachloride, dichloroacetic acid and trichloroacetic acid were calculated to 0.041, 0.240, 0.913 and 2.39 mg/kg/day by the exposure algorithm from the Japan National Institute of Technology and Evaluation, respectively. According to the calculated result, the total estimated human exposure of chloroform were determined to exceed the tolerable concentration of inhalation exposure presented by the World Health Organization. The DBPs should be controlled to the lowest concentrations in the chlorine-containing household cleansing products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of nitrogen dioxide on pulmonary function in human subjects: an environmental chamber study

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

Kerr, H.D.; Kulle, T.J.; McIlhany, M.L.

Twenty human subjects with asthma and chronic bronchitis and 10 normal, healthy adults were exposed to 0.5 ppM of nitrogen dioxide for 2 h in an environmental chamber. Seven of the 13 subjects with asthma experienced symptoms with exposure, while only one each of the subjects with chronic bronchitis and the healthy, normal group experienced symptoms. Significant pulmonary function changes from control values with exposure to NO/sub 2/ were observed in decreased quasistatic compliance for the 10 normal subjects and the 20 subjects with asthma and chronic bronchitis. In addition, functional residual capacity increased significantly for the 20 subjects withmore » asthma and chronic bronchitis. The subjects with asthma and the subjects with chronic bronchitis as separate groups, however, did not show any significant changes with exposure. With this study we are reasonably confident that exposure of subjects with asthma and chronic bronchitis to 0.5 ppM NO/sub 2/ for 2 h does not produce a significant decrement in their pulmonary function.« less

Acute effects of cigarette smoke exposure on experimental skin flaps

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

Nolan, J.; Jenkins, R.A.; Kurihara, K.

1985-04-01

Random vascular patterned caudally based McFarlane-type skin flaps were elevated in groups of Fischer 344 rats. Groups of rats were then acutely exposed on an intermittent basis to smoke generated from well-characterized research filter cigarettes. Previously developed smoke inhalation exposure protocols were employed using a Maddox-ORNL inhalation exposure system. Rats that continued smoke exposure following surgery showed a significantly greater mean percent area of flap necrosis compared with sham-exposed groups or control groups not exposed. The possible pathogenesis of this observation as well as considerations and correlations with chronic human smokers are discussed. Increased risks of flap necrosis by smokingmore » in the perioperative period are suggested by this study.« less

Aqueous exposure to the progestin, levonorgestrel, alters anal fin development and reproductive behavior in the eastern mosquitofish (Gambusia holbrooki)

USGS Publications Warehouse

Frankel, Tyler E.; Meyer, Michael T.; Orlando, Edward F.

2016-01-01

Endogenous progestogens are important regulators of vertebrate reproduction. Synthetic progestins are components of human contraceptive and hormone replacement pharmaceuticals. Both progestogens and progestins enter the environment through a number of sources, and have been shown to cause profound effects on reproductive health in various aquatic vertebrates. Progestins are designed to bind human progesterone receptors, but they also have been shown to strongly activate androgen receptors in fish. Levonorgestrel (LNG) activates fish androgen receptors and induces development of male secondary sex characteristics in females of other species. Although behavior has been postulated to be a sensitive early indicator of exposure to certain environmental contaminants, no such research on the reproductive behavior of gestagen-exposed fish has been conducted to date. The goal of our study was to examine the exposure effects of a human contraceptive progestin, LNG, on the reproductive development and behavior of the viviparous eastern mosquitofish (Gambusia holbrooki). Internal fertilization is a requisite characteristic of viviparous species, and is enabled by an androgen driven elongation of the anal fin into the male gonopodium (i.e., phallus). In this study, we exposed adult mosquitofish to ethanol (EtOH control), 10 ng/L, and 100 ng/L LNG for 8 d using a static replacement exposure design. After 8 d, a subset of males and females from each treatment were examined for differences in the 4:6 anal fin ratio. In addition, paired social interaction trials were performed using individual control males and control females or females treated 10 ng/L or 100 ng/L LNG. Female mosquitofish exposed to LNG were masculinized as evidenced by the elongation of the anal fin rays, a feature normal to males and abnormal to females. LNG caused significant increases in the 4:6 anal fin ratios of female mosquitofish in both the 10 ng/L and 100 ng/L treatments, although these differences were not significant between the two treatments. LNG caused significant increases in the 4:6 anal fin ratio of males exposed to 100 ng/L, with no effects observed in the 10 ng/L treatment. In addition, the reproductive behavior of control males paired with female mosquitofish exposed to 100 ng/L LNG was also altered, for these males spent more time exhibiting no reproductive behavior, had decreased attending behavior, and a lower number of gonopodial thrusts compared to control males paired to control female mosquitofish. Given the rapid effects on both anal fin morphology and behavior observed in this study, the mosquitofish is an excellent sentinel species for the detection of exposure to LNG and likely other 19-nortestosterone derived contraceptive progestins in the environment.

Isoflurane anesthesia has long-term consequences on motor and behavioral development in infant rhesus macaques

PubMed Central

Coleman, Kristine; Robertson, Nicola D.; Dissen, Gregory A.; Neuringer, Martha D.; Martin, L. Drew; Cuzon Carlson, Verginia C.; Kroenke, Christopher; Fair, Damien; Brambrink, Ansgar

2016-01-01

Background Experimental evidence correlates anesthetic exposure during early development with neuronal and glial injury and death as well as behavioral and cognitive impairments in young animals. Several, although not all, retrospective human studies of neurocognitive and behavioral disorders following childhood exposure to anesthesia suggest a similar association. Few studies have specifically investigated the effects of infant anesthesia exposure on subsequent neurobehavioral development. Using a highly translational nonhuman primate model, we investigated the potential dose-dependent effects of anesthesia across the first year of development. Methods We examined effects of single or multiple early postnatal isoflurane exposures on subsequent behavioral development in 24 socially reared rhesus macaques. Infants were exposed to 5-h of isoflurane anesthesia either once, three times, or not at all (control). We assessed reflex development and anxiety using standardized tests. At approximately one year, infants (n=23) were weaned and housed indoors with 5-6 other subjects. We recorded their response to this move and re-assessed anxiety. Results Compared to controls, animals exposed to repeated isoflurane (ISO-3) presented with motor reflex deficits at 1 month (median, range: ISO-3= 2 [1–5] versus control= 5 [3–7], p<0.005) and responded to their new social environment with increased anxiety (median, range: ISO-3=0.4 bouts/minute [0.2–0.6]; control= 0.25 [0.1–0.3], p,0.05) and affiliative/appeasement behavior (median, range: ISO-3=0.1 bouts/min [0–0.2]; control= 0 [0–0.1], p<0.01) at 12 months. There were no statistically significant behavioral alterations after single isoflurane exposure. Conclusions Neonatal exposure to isoflurane, particularly when repeated, has long-term behavioral consequences affecting both motor and socio-emotional aspects of behavior. PMID:27749311

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

Global, local and focused geographic clustering for case-control data with residential histories

PubMed Central

Jacquez, Geoffrey M; Kaufmann, Andy; Meliker, Jaymie; Goovaerts, Pierre; AvRuskin, Gillian; Nriagu, Jerome

2005-01-01

Background This paper introduces a new approach for evaluating clustering in case-control data that accounts for residential histories. Although many statistics have been proposed for assessing local, focused and global clustering in health outcomes, few, if any, exist for evaluating clusters when individuals are mobile. Methods Local, global and focused tests for residential histories are developed based on sets of matrices of nearest neighbor relationships that reflect the changing topology of cases and controls. Exposure traces are defined that account for the latency between exposure and disease manifestation, and that use exposure windows whose duration may vary. Several of the methods so derived are applied to evaluate clustering of residential histories in a case-control study of bladder cancer in south eastern Michigan. These data are still being collected and the analysis is conducted for demonstration purposes only. Results Statistically significant clustering of residential histories of cases was found but is likely due to delayed reporting of cases by one of the hospitals participating in the study. Conclusion Data with residential histories are preferable when causative exposures and disease latencies occur on a long enough time span that human mobility matters. To analyze such data, methods are needed that take residential histories into account. PMID:15784151

TNF-α inhibition using etanercept prevents noise-induced hearing loss by improvement of cochlear blood flow in vivo.

PubMed

Arpornchayanon, Warangkana; Canis, Martin; Ihler, Friedrich; Settevendemie, Claudia; Strieth, Sebastian

2013-08-01

Exposure to loud noise can impair cochlear microcirculation and cause noise-induced hearing loss (NIHL). TNF-α signaling has been shown to be activated in NIHL and to control spiral modiolar artery vasoconstriction that regulates cochlear microcirculation. It was the aim of this experimental study to analyse the effects of the TNF-α inhibitor etanercept on cochlear microcirculation and hearing threshold shift in NIHL in vivo. After assessment of normacusis using ABR, loud noise (106 dB SPL, 30 minutes) was applied on both ears in guinea pigs. Etanercept was administered systemically after loud noise exposure while control animals received a saline solution. In vivo fluorescence microscopy of strial capillaries was performed after surgical exposure of the cochlea for microcirculatory analysis. ABR measurements were derived from the contralateral ear. Guinea pigs (n = 6, per group). Compared to controls, cochlear blood flow in strial capillary segments was significantly increased in etanercept-treated animals. Additionally, hearing threshold was preserved in animals receiving the TNF-α inhibitor in contrast to a significant threshold raising in controls. TNF-α inhibition using etanercept improves cochlear microcirculation and protects hearing levels after loud noise exposure and appears as a promising treatment strategy for human NIHL.

Analysis of proto-oncogene and heat-shock protein gene expression in human derived cell-lines exposed in vitro to an intermittent 1.9 GHz pulse-modulated radiofrequency field.

PubMed

Chauhan, Vinita; Mariampillai, Anusiyanthan; Gajda, Greg B; Thansandote, Artnarong; McNamee, James P

2006-05-01

Several studies have reported that radiofrequency (RF) fields, as emitted by mobile phones, may cause changes in gene expression in cultured human cell-lines. The current study was undertaken to evaluate this possibility in two human-derived immune cell-lines. HL-60 and Mono-Mac-6 (MM6) cells were individually exposed to intermittent (5 min on, 10 min off) 1.9 GHz pulse-modulated RF fields at a average specific absorption rate (SAR) of 1 and 10 W/kg at 37 +/- 0.5 degrees C for 6 h. Concurrent negative and positive (heat-shock for 1 h at 43 degrees C) controls were conducted with each experiment. Immediately following RF field exposure (T = 6 h) and 18 h post-exposure (T = 24 h), cell pellets were collected from each of the culture dishes and analyzed for transcript levels of proto-oncogenes (c-jun, c-myc and c-fos) and the stress-related genes (heat shock proteins (HSP) HSP27 and HSP70B) by quantitative reverse transcriptase polymerase chain reaction (RT-PCR). No significant effects were observed in mRNA expression of HSP27, HSP70, c-jun, c-myc or c-fos between the sham and RF-exposed groups, in either of the two cell-lines. However, the positive (heat-shock) control group displayed a significant elevation in the expression of HSP27, HSP70, c-fos and c-jun in both cell-lines at T = 6 and 24 h, relative to the sham and negative control groups. This study found no evidence that exposure of cells to non-thermalizing levels of 1.9 GHz pulse-modulated RF fields can cause any detectable change in stress-related gene expression.

NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS): OPPORTUNITIES AND LESSONS LEARNED

EPA Science Inventory

The National Human Exposure Assessment Survey (NHEXAS) in its fullest sense is a conceptual design, which upon implementation, will have long-term implications to exposure research and assessment. The ultimate goal is to document national distribution of human exposure to pote...

AN APPROACH TO METHODS DEVELOPMENT FOR HUMAN EXPOSURE ASSESSMENT STUDIES

EPA Science Inventory

Human exposure assessment studies require methods that are rapid, cost-effective and have a high sample through-put. The development of analytical methods for exposure studies should be based on specific information for individual studies. Human exposure studies suggest that di...

Pathogen survival trajectories: an eco-environmental approach to the modeling of human campylobacteriosis ecology.

PubMed Central

Skelly, Chris; Weinstein, Phil

2003-01-01

Campylobacteriosis, like many human diseases, has its own ecology in which the propagation of human infection and disease depends on pathogen survival and finding new hosts in order to replicate and sustain the pathogen population. The complexity of this process, a process common to other enteric pathogens, has hampered control efforts. Many unknowns remain, resulting in a poorly understood disease ecology. To provide structure to these unknowns and help direct further research and intervention, we propose an eco-environmental modeling approach for campylobacteriosis. This modeling approach follows the pathogen population as it moves through the environments that define the physical structure of its ecology. In this paper, we term the ecologic processes and environments through which these populations move "pathogen survival trajectories." Although such a modeling approach could have veterinary applications, our emphasis is on human campylobacteriosis and focuses on human exposures to Campylobacter through feces, food, and aquatic environments. The pathogen survival trajectories that lead to human exposure include ecologic filters that limit population size, e.g., cooking food to kill Campylobacter. Environmental factors that influence the size of the pathogen reservoirs include temperature, nutrient availability, and moisture availability during the period of time the pathogen population is moving through the environment between infected and susceptible hosts. We anticipate that the modeling approach proposed here will work symbiotically with traditional epidemiologic and microbiologic research to help guide and evaluate the acquisition of new knowledge about the ecology, eventual intervention, and control of campylobacteriosis. PMID:12515674

Maternal occupational exposure to polycyclic aromatic hydrocarbons and congenital heart defects among offspring in the national birth defects prevention study.

PubMed

Lupo, Philip J; Symanski, Elaine; Langlois, Peter H; Lawson, Christina C; Malik, Sadia; Gilboa, Suzanne M; Lee, Laura J; Agopian, A J; Desrosiers, Tania A; Waters, Martha A; Romitti, Paul A; Correa, Adolfo; Shaw, Gary M; Mitchell, Laura E

2012-11-01

There is evidence in experimental model systems that exposure to polycyclic aromatic hydrocarbons (PAHs) results in congenital heart defects (CHDs); however, to our knowledge, this relationship has not been examined in humans. Therefore, we conducted a case-control study assessing the association between estimated maternal occupational exposure to PAHs and CHDs in offspring. Data on CHD cases and control infants were obtained from the National Birth Defects Prevention Study for the period of 1997 to 2002. Exposure to PAHs was assigned by industrial hygienist consensus, based on self-reported maternal occupational histories from 1 month before conception through the third month of pregnancy. Logistic regression was used to evaluate the association between maternal occupational PAH exposure and specific CHD phenotypic subtypes among offspring. The prevalence of occupational PAH exposure was 4.0% in CHD case mothers (76/1907) and 3.6% in control mothers (104/2853). After adjusting for maternal age, race or ethnicity, education, smoking, folic acid supplementation, and study center, exposure was not associated with conotruncal defects (adjusted odds ratio [AOR], 0.98; 95% confidence interval [CI], 0.58-1.67), septal defects (AOR, 1.28; 95% CI, 0.86-1.90), or with any isolated CHD subtype. Our findings do not support an association between potential maternal occupational exposure to PAHs and various CHDs in a large, population-based study. For CHD phenotypic subtypes in which modest nonsignificant associations were observed, future investigations could be improved by studying populations with a higher prevalence of PAH exposure and by incorporating information on maternal and fetal genotypes related to PAH metabolism. Birth Defects Research (Part A), 2012. Copyright © 2012 Wiley Periodicals, Inc.

Derivation of an occupational exposure level for manganese in welding fumes.

PubMed

Bailey, Lisa A; Kerper, Laura E; Goodman, Julie E

2018-01-01

Exposure to high levels of manganese (Mn) in occupational settings is known to lead to adverse neurological effects. Since Mn is an essential nutrient, there are mechanisms that maintain its homeostatic control in the body, and there is some level of Mn in air that does not perturb Mn homeostasis. However, the Mn exposure concentrations at which no adverse effects are expected in occupational settings vary considerably across regulatory agencies. We set out to derive a Mn Occupational Exposure Level (OEL) for welders based on a review of studies that evaluated Mn exposure concentrations from welding fumes and: (1) neurological effects in welders; (2) levels of Mn in the brains of welders (via pallidal index [PI] estimated from magnetic resonance imaging [MRI]); (3) other biomarkers of Mn exposure in welders (i.e., blood and urine); and (4) Mn brain concentrations, PI, and corresponding neurological effects in non-human primates. Our analysis suggests uncertainty in quantifying dose-response associations for Mn from many of the occupational welding studies. The few welding studies that adequately estimate exposure suggest a possible OEL of 100-140μg/m 3 for respirable Mn. This range is consistent with other epidemiology studies, studies of biomarkers of Mn exposure in welders, and with studies in non-human primates, though future studies could provide a stronger basis for deriving a Mn occupational guideline for welders. Copyright © 2017 Elsevier B.V. All rights reserved.

Uptake and disposition of 1,1-difluoroethane (HFC-152a) in humans.

PubMed

Ernstgård, Lena; Sjögren, Bengt; Dekant, Wolfgang; Schmidt, Tobias; Johanson, Gunnar

2012-02-25

The aim of this study was to determine the toxicokinetics of inhaled 1,1-difluoroethane (HFC-152a) in humans. Healthy volunteers were exposed to 0, 200 or 1000 ppm 1,1-difluoroethane for 2h at light exercise in an exposure chamber. Capillary blood, urine and exhaled air were sampled up to 22 h post-exposure and analyzed for 1,1-difluoroethane. Fluoride and other potential metabolites were analyzed in urine. Symptoms of irritation and central nervous system effects were rated and inflammatory markers were analyzed in blood. Within a few minutes of exposure to 200 and 1000 ppm, 1,1-difluoroethane increased rapidly in blood and reached average levels of 7.4 and 34.3 μM, respectively. The post-exposure decreases in blood were fast and parallel to those in exhaled air. The observed time courses in blood and breath agreed well with those obtained with the PBPK model. The PBPK simulations indicate a net uptake during exposure to 1000 ppm of 6.6 mmol (6.7%) which corresponds to the amount exhaled post-exposure. About 20 μmol excess fluoride (0.013% of inhaled 1,1-difluoroethane on a molar basis) was excreted in urine after exposure to 1000 ppm, compared to control. No fluorine-containing metabolites were detected in urine. Symptom ratings and changes in inflammatory markers revealed no exposure-related effects. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Surveillance and control of rabies in La Reunion, Mayotte, and Madagascar

PubMed Central

2013-01-01

Mayotte and La Reunion islands are currently free of animal rabies and surveillance is performed by the French Human and Veterinary Public Health Services. However, dog rabies is still enzootic in Madagascar with 4 to 10 confirmed human cases each year. The number of antirabies medical centres in Madagascar is still scarce to provide easy access to the local population for post-exposure rabies prophylaxis. Furthermore, stray dog populations are considerable and attempts to control rabies by mass campaigns of dog vaccination have not received sufficient attention from the national health authorities. To address these challenges, an expanded program to control rabies needs to be initiated by the Malagasy authorities. PMID:24016204

The effect of electromagnetic radiation emitted by display screens on cell oxygen metabolism – in vitro studies

PubMed Central

Henrykowska, Gabriela A.; Pacholski, Krzysztof; Śmigielski, Janusz; Rutkowski, Maciej; Dziedziczak-Buczyńska, Maria; Buczyński, Andrzej

2015-01-01

Introduction Research studies carried out for decades have not solved the problem of the effect of electromagnetic radiation of various frequency and strength on the human organism. Due to this fact, we decided to investigate the changes taking place in human blood platelets under the effect of electromagnetic radiation (EMR) emitted by LCD monitors. Material and methods The changes of selected parameters of oxygen metabolism were measured, i.e. reactive oxygen species concentration, enzymatic activity of antioxidant defence proteins – superoxide dismutase (SOD-1) and catalase (CAT) – and malondialdehyde concentration (MDA). A suspension of human blood platelets was exposed to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity for 30 and 60 min. The level of changes of the selected parameters of oxidative stress was determined after the exposure and compared to the control samples (not exposed). Results The measurements revealed an increase of the concentration of reactive oxygen species. The largest increase of ROS concentration vs. the control sample was observed after exposure to EMF of 220 V/m intensity for 60 min (from x = 54.64 to x = 72.92). The measurement of MDA concentration demonstrated a statistically significant increase after 30-min exposure to an EMF of 220 V/m intensity in relation to the initial values (from x = 3.18 to x = 4.41). The enzymatic activity of SOD-1 decreased after exposure (the most prominent change was observed after 60-min and 220 V/m intensity from x = 3556.41 to x = 1084.83). The most significant change in activity of catalase was observed after 60 min and 220 v/m exposure (from x = 6.28 to x = 4.15). Conclusions The findings indicate that exposure to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity may cause adverse effects within blood platelets’ oxygen metabolism and thus may lead to physiological dysfunction of the organism. PMID:26788099

A human life-stage physiologically based pharmacokinetic and pharmacodynamic model for chlorpyrifos: development and validation.

PubMed

Smith, Jordan Ned; Hinderliter, Paul M; Timchalk, Charles; Bartels, Michael J; Poet, Torka S

2014-08-01

Sensitivity to some chemicals in animals and humans are known to vary with age. Age-related changes in sensitivity to chlorpyrifos have been reported in animal models. A life-stage physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) model was developed to predict disposition of chlorpyrifos and its metabolites, chlorpyrifos-oxon (the ultimate toxicant) and 3,5,6-trichloro-2-pyridinol (TCPy), as well as B-esterase inhibition by chlorpyrifos-oxon in humans. In this model, previously measured age-dependent metabolism of chlorpyrifos and chlorpyrifos-oxon were integrated into age-related descriptions of human anatomy and physiology. The life-stage PBPK/PD model was calibrated and tested against controlled adult human exposure studies. Simulations suggest age-dependent pharmacokinetics and response may exist. At oral doses ⩾0.6mg/kg of chlorpyrifos (100- to 1000-fold higher than environmental exposure levels), 6months old children are predicted to have higher levels of chlorpyrifos-oxon in blood and higher levels of red blood cell cholinesterase inhibition compared to adults from equivalent doses. At lower doses more relevant to environmental exposures, simulations predict that adults will have slightly higher levels of chlorpyrifos-oxon in blood and greater cholinesterase inhibition. This model provides a computational framework for age-comparative simulations that can be utilized to predict chlorpyrifos disposition and biological response over various postnatal life stages. Copyright © 2013 Elsevier Inc. All rights reserved.

Mercury risk assessment combining internal and external exposure methods for a population living near a municipal solid waste incinerator.

PubMed

Deng, Chunyan; Xie, Han; Ye, Xuejie; Zhang, Haoran; Liu, Maodian; Tong, Yindong; Ou, Langbo; Yuan, Wen; Zhang, Wei; Wang, Xuejun

2016-12-01

Risk assessments for human health have been conducted for municipal solid waste incinerators (MSWIs) in many western countries, whereas only a few risk assessments have been performed for MSWIs in developing countries such as China where the use of waste incineration is increasing rapidly. To assess the mercury exposure risks of a population living near the largest MSWI in South China, we combined internal exposure and external exposure assessment with an individual-specific questionnaire. The mercury concentrations in air, soil, and locally collected food around the MSWI were assessed. The total mercury (T-Hg) and methylmercury (MeHg) of 447 blood samples from a control group, residential exposure group, and MSWI workers were measured. The internal and external exposures of the subject population were analyzed. Significant difference in MeHg concentrations was observed between the control group and the exposed group, between the control group and the MSWI workers, and between the exposed group and the MSWI workers (median levels: 0.70 μg/L, 0.81 μg/L, and 1.02 μg/L for the control group, exposed group, and MSWI workers, respectively). The MeHg/T-Hg ratio was 0.51 ± 0.19, 0.59 ± 0.17 and 0.58 ± 0.25, respectively. Multiple linear regression analysis indicated that MeHg concentrations were positively correlated with the gaseous mercury in the air. Combining internal and external exposure assessment showed that the direct contribution of MSWI emissions was minor compared with the dietary contribution. The external and internal exposures were well matched with each other. This study also suggested that an integrated method combining internal and external exposure assessment with an individual-specific questionnaire is feasible to assess the risks for a population living near a MSWI. Copyright © 2016 Elsevier Ltd. All rights reserved.

Occupational and environmental lead exposure in Port Harcourt, Nigeria: analysis of its association with renal function indices.

PubMed

Alasia, D D; Emem-Chioma, P C; Wokoma, F S

2010-01-01

In spite of the high risk of lead exposure in Nigeria, there is a paucity of data on the occupational and environmental burden of lead exposure and its impact on human health especially its nephrotoxic effects. This study aims to assess the degree of occupational and environmental lead exposure in Port Harcourt Nigeria and the relationship between lead exposure and indices of renal function. A cross sectional comparative study of 190 aduIt subjects with occupational lead exposure and 80 matched controls. Blood lead was used as the biomarker of lead exposure. Serum urea, creatinine, uric acid, urine albumin and glomerular filtration rate were the renal function indices measured. Occupationally lead exposed subjects had higher mean blood lead 50.37 +/- 24.58 ug/dI, than controls 41.40 +/- 26.85 ug/dl (p = 0.008). The mean values of serum urea, creatinine and uric acid were significantly higher in study subjects compared to controls 3.06 +/- 0.81 mmol/L vs. 2.7 +/- 0.84 mmol/L (p = 0.002), 87.2 +/- 14.30 umol/L vs. 80.68 +/- 14.70 umol/L (p = 0.001) and 271.93 +/- 71.18 umol/L vs. 231.1 +/- 62.70 umol/L (p = 0.000) respectively. Creatinine clearance was significantly lower in subjects compared to controls 98.86 +/- 21.26 mI/min/1.72m2 vs. 108.18 +/- 25.16 mI/min/1.72m2 (p = 0.002). Blood lead correlated positively only with blood urea [r = .031, r2 = .017, p = .031] and negatively [r = -.144, r2 = .02 1, p = .018] with serum phosphate. The level of environmental and occupational lead exposure in Port Harcourt, Nigeria is high, with occupational lead exposure increasing the risk of lead toxicity and renal function impairment.

Evaluation of the bleached human enamel by Scanning Electron Microscopy.

PubMed

Miranda, Carolina Baptista; Pagani, Clovis; Benetti, Ana Raquel; Matuda, Fábio da Silva

2005-06-01

Since bleaching has become a popular procedure, the effect of peroxides on dental hard tissues is of great interest in research. The aim of this in vitro study was to perform a qualitative analysis of the human enamel after the application of in-office bleaching agents, using Scanning Electron Microscopy (SEM). Twenty intact human third molars extracted for orthodontic reasons were randomly divided into four groups (n=5) treated as follows: G1- storage in artificial saliva (control group); G2- four 30-minute applications of 35% carbamide peroxide (total exposure: 2h); G3- four 2-hour exposures to 35% carbamide peroxide (total exposure: 8h); G4- two applications of 35% hydrogen peroxide, which was light-activated with halogen lamp at 700mW/cm² during 7min and remained in contact with enamel for 20min (total exposure: 40min). All bleaching treatments adopted in this study followed the application protocols advised by manufacturers. Evaluation of groups submitted to 35% carbamide peroxide was carried out after two time intervals (30 minutes and 2 hours per session), following the extreme situations recommended by the manufacturer. Specimens were prepared for SEM analysis performing gold sputter coating under vacuum and were examined using 15kV at 500x and 2000x magnification. Morphological alterations on the enamel surface were similarly detected after bleaching with either 35% carbamide peroxide or 35% hydrogen peroxide. Surface porosities were characteristic of an erosive process that took place on human enamel. Depression areas, including the formation of craters, and exposure of enamel rods could also be detected. Bleaching effects on enamel morphology were randomly distributed throughout enamel surface and various degrees of enamel damage could be noticed. In-office bleaching materials may adversely affect enamel morphology and therefore should be used with caution.

U.S. domestic cats as sentinels for perfluoroalkyl substances: Possible linkages with housing, obesity, and disease.

PubMed

Bost, Phillip C; Strynar, Mark J; Reiner, Jessica L; Zweigenbaum, Jerry A; Secoura, Patricia L; Lindstrom, Andrew B; Dye, Janice A

2016-11-01

Perfluoroalkyl substances (PFAS), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are persistent, globally distributed, anthropogenic compounds. The primary source(s) for human exposure are not well understood although within home exposure is likely important since many consumer products have been treated with different PFAS, and people spend much of their lives indoors. Herein, domestic cats were used as sentinels to investigate potential exposure and health linkages. PFAS in serum samples of 72 pet and feral cats, including 11 healthy and 61 with one or more primary disease diagnoses, were quantitated using high-resolution time-of-flight mass spectroscopy. All but one sample had detectable PFAS, with PFOS and perfluorohexane sulfonate (PFHxS) ranging from

Phosphoproteomics profiling of human skin fibroblast cells reveals pathways and proteins affected by low doses of ionizing radiation.

PubMed

Yang, Feng; Waters, Katrina M; Miller, John H; Gritsenko, Marina A; Zhao, Rui; Du, Xiuxia; Livesay, Eric A; Purvine, Samuel O; Monroe, Matthew E; Wang, Yingchun; Camp, David G; Smith, Richard D; Stenoien, David L

2010-11-30

High doses of ionizing radiation result in biological damage; however, the precise relationships between long-term health effects, including cancer, and low-dose exposures remain poorly understood and are currently extrapolated using high-dose exposure data. Identifying the signaling pathways and individual proteins affected at the post-translational level by radiation should shed valuable insight into the molecular mechanisms that regulate dose-dependent responses to radiation. We have identified 7117 unique phosphopeptides (2566 phosphoproteins) from control and irradiated (2 and 50 cGy) primary human skin fibroblasts 1 h post-exposure. Semi-quantitative label-free analyses were performed to identify phosphopeptides that are apparently altered by radiation exposure. This screen identified phosphorylation sites on proteins with known roles in radiation responses including TP53BP1 as well as previously unidentified radiation-responsive proteins such as the candidate tumor suppressor SASH1. Bioinformatic analyses suggest that low and high doses of radiation affect both overlapping and unique biological processes and suggest a role for MAP kinase and protein kinase A (PKA) signaling in the radiation response as well as differential regulation of p53 networks at low and high doses of radiation. Our results represent the most comprehensive analysis of the phosphoproteomes of human primary fibroblasts exposed to multiple doses of ionizing radiation published to date and provide a basis for the systems-level identification of biological processes, molecular pathways and individual proteins regulated in a dose dependent manner by ionizing radiation. Further study of these modified proteins and affected networks should help to define the molecular mechanisms that regulate biological responses to radiation at different radiation doses and elucidate the impact of low-dose radiation exposure on human health.

Phosphoproteomics Profiling of Human Skin Fibroblast Cells Reveals Pathways and Proteins Affected by Low Doses of Ionizing Radiation

PubMed Central

Yang, Feng; Waters, Katrina M.; Miller, John H.; Gritsenko, Marina A.; Zhao, Rui; Du, Xiuxia; Livesay, Eric A.; Purvine, Samuel O.; Monroe, Matthew E.; Wang, Yingchun; Camp, David G.; Smith, Richard D.; Stenoien, David L.

2010-01-01

Background High doses of ionizing radiation result in biological damage; however, the precise relationships between long-term health effects, including cancer, and low-dose exposures remain poorly understood and are currently extrapolated using high-dose exposure data. Identifying the signaling pathways and individual proteins affected at the post-translational level by radiation should shed valuable insight into the molecular mechanisms that regulate dose-dependent responses to radiation. Principal Findings We have identified 7117 unique phosphopeptides (2566 phosphoproteins) from control and irradiated (2 and 50 cGy) primary human skin fibroblasts 1 h post-exposure. Semi-quantitative label-free analyses were performed to identify phosphopeptides that are apparently altered by radiation exposure. This screen identified phosphorylation sites on proteins with known roles in radiation responses including TP53BP1 as well as previously unidentified radiation-responsive proteins such as the candidate tumor suppressor SASH1. Bioinformatic analyses suggest that low and high doses of radiation affect both overlapping and unique biological processes and suggest a role for MAP kinase and protein kinase A (PKA) signaling in the radiation response as well as differential regulation of p53 networks at low and high doses of radiation. Conclusions Our results represent the most comprehensive analysis of the phosphoproteomes of human primary fibroblasts exposed to multiple doses of ionizing radiation published to date and provide a basis for the systems-level identification of biological processes, molecular pathways and individual proteins regulated in a dose dependent manner by ionizing radiation. Further study of these modified proteins and affected networks should help to define the molecular mechanisms that regulate biological responses to radiation at different radiation doses and elucidate the impact of low-dose radiation exposure on human health. PMID:21152398

The Effect of D-cycloserine on Subliminal Cue Exposure in Spider Fearful Individuals

PubMed Central

Gutner, Cassidy A.; Weinberger, Joel; Hofmann, Stefan G.

2012-01-01

Research on d-cycloserine (DCS) has demonstrated a significant effect on symptom reduction in human studies that utilized conventional exposure-based approaches. Recent studies have offered promising results for targeting fears through subliminal paradigms. In this double-blind, randomized placebo controlled study, 45 spider fearful individuals received DCS or placebo pills prior to completing a subliminal cue exposure task to images of spiders. Participants completed self-report questionnaires and a behavioral approach task to a live caged tarantula. After repeated exposure to subliminal spider cues, participants in the DCS group reported a greater reduction in disgust than individuals in the placebo group. No difference was observed in fear ratings. These findings suggest that DCS augments the reduction in disgust in spider fearful subjects after subliminal exposure to spider cues. PMID:22992160

Hyperbranched polyglycerol is an efficacious and biocompatible novel osmotic agent in a rodent model of peritoneal dialysis.

PubMed

Mendelson, Asher A; Guan, Qiunong; Chafeeva, Irina; da Roza, Gerald A; Kizhakkedathu, Jayachandran N; Du, Caigan

2013-01-01

To enhance the effectiveness of peritoneal dialysis (PD), new biocompatible PD solutions may be needed. The present study was designed to test the efficacy and biocompatibility of hyperbranched polyglycerol (HPG)-a nontoxic, nonimmunogenic water-soluble polyether polymer-in PD. Adult Sprague-Dawley rats were instilled with 30 mL HPG solution (molecular weight 3 kDa; 2.5% - 15%) or control glucose PD solution (2.5% Dianeal: Baxter Healthcare Corporation, Deerfield, IL, USA), and intraperitoneal fluid was recovered after 4 hours. Peritoneal injury and cellular infiltration were determined by histologic and flow cytometric analysis. Human peritoneal mesothelial cells were assessed for viability in vitro after 3 hours of PD fluid exposure. The 15% HPG solution achieved a 4-hour dose-related ultrafiltration up to 43.33 ± 5.24 mL and a dose-related urea clearance up to 39.17 ± 5.21 mL, results that were superior to those with control PD solution (p < 0.05). The dialysate-to-plasma (D/P) ratios of urea with 7.5% and 15% HPG solution were not statistically different from those with control PD solution. Compared with fluid recovered from the control group, fluid recovered from the HPG group contained proportionally fewer neutrophils (3.63% ± 0.87% vs 9.31% ± 2.89%, p < 0.0001). Detachment of mesothelial cells positive for human bone marrow endothelial protein 1 did not increase in the HPG group compared with the stain control (p = 0.1832), but it was elevated in the control PD solution group (1.62% ± 0.68% vs 0.41% ± 0.31%, p = 0.0031). Peritoneal biopsies from animals in the HPG PD group, compared with those from control PD animals, demonstrated less neutrophilic infiltration and reduced thickness. Human peritoneal mesothelial cell survival after HPG exposure was superior in vitro (p < 0.0001, 7.5% HPG vs control; p < 0.01, 15% HPG vs control). Exposure to glucose PD solution induced cytoplasmic vacuolation and caspase 3-independent necrotic cell death that was not seen with HPG solution. Our novel HPG PD solution demonstrated effective ultrafiltration and waste removal with reduced peritoneal injury in a rodent model of PD.

Hyperbranched Polyglycerol Is an Efficacious and Biocompatible Novel Osmotic Agent in a Rodent Model of Peritoneal Dialysis

PubMed Central

Mendelson, Asher A.; Guan, Qiunong; Chafeeva, Irina; da Roza, Gerald A.; Kizhakkedathu, Jayachandran N.; Du, Caigan

2013-01-01

♦ Objectives: To enhance the effectiveness of peritoneal dialysis (PD), new biocompatible PD solutions may be needed. The present study was designed to test the efficacy and biocompatibility of hyperbranched polyglycerol (HPG)—a nontoxic, nonimmunogenic water-soluble polyether polymer—in PD. ♦ Methods: Adult Sprague-Dawley rats were instilled with 30 mL HPG solution (molecular weight 3 kDa; 2.5% - 15%) or control glucose PD solution (2.5% Dianeal: Baxter Healthcare Corporation, Deerfield, IL, USA), and intraperitoneal fluid was recovered after 4 hours. Peritoneal injury and cellular infiltration were determined by histologic and flow cytometric analysis. Human peritoneal mesothelial cells were assessed for viability in vitro after 3 hours of PD fluid exposure. ♦ Results: The 15% HPG solution achieved a 4-hour dose-related ultrafiltration up to 43.33 ± 5.24 mL and a dose-related urea clearance up to 39.17 ± 5.21 mL, results that were superior to those with control PD solution (p < 0.05). The dialysate-to-plasma (D/P) ratios of urea with 7.5% and 15% HPG solution were not statistically different from those with control PD solution. Compared with fluid recovered from the control group, fluid recovered from the HPG group contained proportionally fewer neutrophils (3.63% ± 0.87% vs 9.31% ± 2.89%, p < 0.0001). Detachment of mesothelial cells positive for human bone marrow endothelial protein 1 did not increase in the HPG group compared with the stain control (p = 0.1832), but it was elevated in the control PD solution group (1.62% ± 0.68% vs 0.41% ± 0.31%, p = 0.0031). Peritoneal biopsies from animals in the HPG PD group, compared with those from control PD animals, demonstrated less neutrophilic infiltration and reduced thickness. Human peritoneal mesothelial cell survival after HPG exposure was superior in vitro (p < 0.0001, 7.5% HPG vs control; p < 0.01, 15% HPG vs control). Exposure to glucose PD solution induced cytoplasmic vacuolation and caspase 3-independent necrotic cell death that was not seen with HPG solution. ♦ Conclusions: Our novel HPG PD solution demonstrated effective ultrafiltration and waste removal with reduced peritoneal injury in a rodent model of PD. PMID:23349194

Report: EPA Does Not Effectively Control or Monitor Imports of Hazardous Waste

EPA Pesticide Factsheets

Report #15-P-0172, July 6, 2015. The EPA lacks explicit authority to block imported shipments of hazardous waste that lack prior EPA consent. This could lead to improper handling and disposal, resulting in unknown human and environmental exposure to toxic

78 FR 25436 - SFIREG Environmental Quality Issues Committee; Notice of Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-01

... human health, environmental exposure to pesticides, and insight into EPA's decision-making process. You.... SUMMARY: The Association of American Pesticide Control Officials (AAPCO)/State FIFRA Issues Research and... External Affairs Division (7506P), Office of Pesticide Programs, Environmental Protection Agency, 1200...

75 FR 6656 - SFIREG Pesticide Operations and Management Working Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-10

... regarding important issues related to human health, environmental exposure to pesticides, and insight into... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0001; FRL-8811-3] SFIREG Pesticide Operations and...: The Association of American Pesticide Control Officials (AAPCO)/State FIFRA Issues Research and...

30 CFR 74.7 - Design and construction requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... while monitoring atmospheres including such water mists. (f) Electromagnetic interference. The CPDM shall meet the following standards for control of and protection from electromagnetic interference. (1... with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz) and 47 CFR...

30 CFR 74.7 - Design and construction requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... while monitoring atmospheres including such water mists. (f) Electromagnetic interference. The CPDM shall meet the following standards for control of and protection from electromagnetic interference. (1... with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz) and 47 CFR...

30 CFR 74.7 - Design and construction requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... while monitoring atmospheres including such water mists. (f) Electromagnetic interference. The CPDM shall meet the following standards for control of and protection from electromagnetic interference. (1... with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz) and 47 CFR...

30 CFR 74.7 - Design and construction requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... while monitoring atmospheres including such water mists. (f) Electromagnetic interference. The CPDM shall meet the following standards for control of and protection from electromagnetic interference. (1... with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz) and 47 CFR...

30 CFR 74.7 - Design and construction requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... while monitoring atmospheres including such water mists. (f) Electromagnetic interference. The CPDM shall meet the following standards for control of and protection from electromagnetic interference. (1... with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz) and 47 CFR...

Effect of UV irradiation on cutaneous cicatrices: a randomized, controlled trial with clinical, skin reflectance, histological, immunohistochemical and biochemical evaluations.

PubMed

Due, Eva; Rossen, Kristian; Sorensen, Lars Tue; Kliem, Anette; Karlsmark, Tonny; Haedersdal, Merete

2007-01-01

The aim of this study was to examine the effect of ultraviolet (UV) irradiation on human cutaneous cicatrices. In this randomized, controlled study, dermal punch biopsy wounds served as a wound healing model. Wounds healed by primary or second intention and were randomized to postoperative solar UV irradiation or to no UV exposure. Evaluations after 5 and 12 weeks included blinded clinical assessments, skin reflectance measurements, histology, immunohistochemistry, and biochemical analyses of the N-terminal propeptide from procollagen-1, hydroxyproline, hydroxylysine, and proline. Twelve weeks postoperatively, UV-irradiated cicatrices healing by second intention: (i) were significantly pointed out as the most disfiguring; (ii) obtained significantly higher scores of colour, infiltration and cicatrix area; and (iii) showed significantly higher increase in skin-reflectance measurements of skin-pigmentation vs. non-irradiated cicatrices. No histological, immunohistochemical or biochemical differences were found. In conclusion, postoperative UV exposure aggravates the clinical appearance of cicatrices in humans.

Synergistic chemotherapy by combined moderate hyperthermia and photochemical internalization.

PubMed

Christie, Catherine; Molina, Stephanie; Gonzales, Jonathan; Berg, Kristian; Nair, Rohit Kumar; Huynh, Khoi; Madsen, Steen J; Hirschberg, Henry

2016-04-01

Combination therapies of photochemical internalization (PCI) and moderate hyperthermia (MHT) were investigated in an in vitro system consisting of human and rat glioma spheroids. PCI using the amphiphilic photosensitizer, AlPcS2a and two anti cancer agents BLM or 5-FU were used. Spheroids were irradiated with λ = 670 nm laser light in an incubator at temperatures ranging from 37 to 44°C. For each temperature investigated, spheroids were divided into 4 groups: control, drug-only, photodynamic therapy (PDT), and PCI. PDT and PCI spheroids were exposed to radiant exposures ranging from 0.3 to 2.5 J cm(-2) using an irradiance of 5 mW cm(-2). Toxicity was evaluated from spheroid growth kinetics. The combination of PCI and MHT resulted in significant increases in BLM efficacy at 44°C for both cell line derived spheroids compared to controls at 37°C over the range of radiant exposures examined. 5-FU PCI was ineffective for the human cell line at both 37 and 44°C.

Use of anticoagulant rodenticides in outdoor urban areas: considerations and proposals for the protection of public health and non-target species.

PubMed

Dutto, M; Di Domenico, D; Rubbiani, M

2018-01-01

Rodent control operations represent an important tool for the prevention and management of infestations, in outdoor environments, by synanthropic rodents (Rattus rattus and R. norvegicus), which are a source of economic and environmental damage with significant sanitary implications. Although the use of anticoagulants is safer to humans and pets compared to the use of acute poisoning substances, an intrinsic hazard of the active ingredients exists, i.e. the possible poisoning of non-target organisms (e.g., children, pets and wildlife) following exposure. The risks arising from the use of anticoagulants for rodent control operations in anthropic contexts can therefore only be mitigated by a proper selection of the active ingredient, bait formulation and administration techniques, since an active ingredient with selective action towards non-target species does not currently exist on the market. This document lists practical proposals aimed at reducing the possibility of toxic exposure to anticoagulant rodenticides and mitigate the toxicological risk of human baits and non-target species.

Hypermethylation of Homeobox A10 by in Utero Diethylstilbestrol Exposure: An Epigenetic Mechanism for Altered Developmental Programming

PubMed Central

Bromer, Jason G.; Wu, Jie; Zhou, Yuping; Taylor, Hugh S.

2009-01-01

Diethylstilbestrol (DES) is a nonsteroidal estrogen that induces developmental anomalies of the female reproductive tract. The homeobox gene HOXA10 controls uterine organogenesis, and its expression is altered after in utero DES exposure. We hypothesized that an epigenetic mechanism underlies DES-mediated alterations in HOXA10 expression. We analyzed the expression pattern and methylation profile of HOXA10 after DES exposure. Expression of HOXA10 is increased in human endometrial cells after DES exposure, whereas Hoxa10 expression is repressed and shifted caudally from its normal location in mice exposed in utero. Cytosine guanine dinucleotide methylation frequency in the Hoxa10 intron was higher in DES-exposed offspring compared with controls (P = 0.017). The methylation level of Hoxa10 was also higher in the caudal portion of the uterus after DES exposure at the promoter and intron (P < 0.01). These changes were accompanied by increased expression of DNA methyltransferases 1 and 3b. No changes in methylation were observed after in vitro or adult DES exposure. DES has a dual mechanism of action as an endocrine disruptor; DES functions as a classical estrogen and directly stimulates HOXA10 expression with short-term exposure, however, in utero exposure results in hypermethylation of the HOXA10 gene and long-term altered HOXA10 expression. We identify hypermethylation as a novel mechanism of DES-induced altered developmental programming. PMID:19299448

Parkinson's Disease and Residential Exposure to Maneb and Paraquat From Agricultural Applications in the Central Valley of California

PubMed Central

Cockburn, Myles; Bronstein, Jeff; Zhang, Xinbo; Ritz, Beate

2009-01-01

Evidence from animal and cell models suggests that pesticides cause a neurodegenerative process leading to Parkinson's disease (PD). Human data are insufficient to support this claim for any specific pesticide, largely because of challenges in exposure assessment. The authors developed and validated an exposure assessment tool based on geographic information systems that integrated information from California Pesticide Use Reports and land-use maps to estimate historical exposure to agricultural pesticides in the residential environment. In 1998–2007, the authors enrolled 368 incident PD cases and 341 population controls from the Central Valley of California in a case-control study. They generated estimates for maneb and paraquat exposures incurred between 1974 and 1999. Exposure to both pesticides within 500 m of the home increased PD risk by 75% (95% confidence interval (CI): 1.13, 2.73). Persons aged ≤60 years at the time of diagnosis were at much higher risk when exposed to either maneb or paraquat alone (odds ratio = 2.27, 95% CI: 0.91, 5.70) or to both pesticides in combination (odds ratio = 4.17, 95% CI: 1.15, 15.16) in 1974–1989. This study provides evidence that exposure to a combination of maneb and paraquat increases PD risk, particularly in younger subjects and/or when exposure occurs at younger ages. PMID:19270050

Active and passive ozone samplers based on a reaction with a binary reagent.

PubMed

Hackney, J D; Avol, E L; Linn, W S; Anderson, K R

1994-02-01

Ozone is one of the most toxic common air pollutants (judging from short-term animal and human exposure studies at realistic concentrations) and one of the most difficult and expensive pollutants to control. Because of ozone's high chemical reactivity, its concentrations may vary greatly over short distances, and fixed-site air quality monitors may not accurately estimate exposures of human populations. Epidemiologic research on ozone's long-term health effects has been inconclusive, partly because of the lack of reliable personal exposure information. The objective of this project was to develop a practical personal ozone exposure monitoring technique, and to document its precision and accuracy in actual use by representatives of freely ranging, ozone-exposed populations. The project site, Los Angeles, is the nation's metropolitan area with the highest level of ozone pollution and, thus, probably the most important locale for personal exposure assessment. Our overall strategy was (1) to select the most promising laboratory technique for ozone detection from published literature and private communications; (2) to design and test personal monitors using this technique; and (3) when feasible, to evaluate concurrently alternative methodologies developed by others. As indicated below, parts 1 and 2 of our strategy yielded a limited success with respect to short-term active sampling, i.e., measuring personal ozone exposure levels during one to two hours with a monitor incorporating a battery-powered air pump of the type used in industrial hygiene investigations. The same approach was not successful in passive sampling, i.e., measuring exposure levels during multihour or multiday periods with a light-weight, diffusion-controlled "badge" sampler having no moving parts. Passive badge samplers could be calibrated reasonably well in laboratory exposures to ozone in otherwise pure air, but they greatly overestimated ozone levels in outdoor ambient air. Part 3 of our strategy yielded more promising information on an alternative passive badge design. After testing and rejecting two other possibilities, we chose a binary organic reagents, 3-methyl-2-benzothiazolinone acetone azine with 2-phenylphenol, as the most promising chemical detector of ozone. Filter papers impregnated with the binary reagent develop a characteristic intense pink color when exposed to ozone. The inventors, J.E. Lambert and associates of Kansas State University, had intended only to develop a rough qualitative ozone monitor (Lambert et al. 1989). However, our initial laboratory testing (in exposure chambers containing ozone in otherwise very clean air, away from humans), revealed fairly accurate quantitative response.(ABSTRACT TRUNCATED AT 400 WORDS)

Regulation of Human Skin Pigmentation in situ by Repetitive UV Exposure – Molecular Characterization of Responses to UVA and/or UVB

PubMed Central

Choi, Wonseon; Miyamura, Yoshinori; Wolber, Rainer; Smuda, Christoph; Reinhold, William; Liu, Hongfang; Kolbe, Ludger; Hearing, Vincent J.

2012-01-01

Ultraviolet (UV) radiation is a major environmental factor that affects pigmentation in human skin and can eventually result in various types of UV-induced skin cancers. The effects of various wavelengths of UV on melanocytes and other types of skin cells in culture have been studied but little is known about gene expression patterns in situ following in situe exposure of human skin to different types of UV (UVA and/or UVB). Paracrine factors expressed by keratinocytes and/or fibroblasts that affect skin pigmentation might be regulated differently by UV, as might their corresponding receptors expressed on melanocytes. To test the hypothesis that different mechanisms are involved in the pigmentary responses of the skin to different types of UV, we used immunohistochemical and whole human genome microarray analyses to characterize human skin in situ to examine how melanocyte-specific proteins and paracrine melanogenic factors are regulated by repetitive exposure to different types of UV compared with unexposed skin as a control. The results show that gene expression patterns induced by UVA or UVB are distinct, UVB eliciting dramatic increases in a large number of genes involved in pigmentation as well as in other cellular functions, while UVA had little or no effect on those. The expression patterns characterize the distinct responses of the skin to UVA or UVB, and identify several potential previously unidentified factors involved in UV-induced responses of human skin. PMID:20147966

AC field exposure study: human exposure to 60-Hz electric fields

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

Silva, J.M.

1985-04-01

The objective of this study was to develop a method of estimating human exposure to the 60 Hz electric fields created by transmission lines. The Activity Systems Model simulates human activities in a variety of situations where exposure to electric fields is possible. The model combines maps of electric fields, activity maps, and experimentally determined activity factors to provide histograms of time spent in electric fields of various strengths in the course of agricultural, recreational, and domestic activities. For corroboration, the study team measured actual human exposure at locations across the United States near transmission lines ranging in voltage frommore » 115 to 1200 kV. The data were collected with a specially designed vest that measures exposure. These data demonstrate the accuracy of the exposure model presented in this report and revealed that most exposure time is spent in fields of magnitudes similar to many household situations. The report provides annual exposure estimates for human activities near transmission lines and in the home and compares them with exposure data from typical laboratory animal experiments. For one exposure index, the cumulative product of time and electric field, exposure during some of the laboratory animal experiments is two to four orders of magnitude greater than cumulative exposure for a human during one year of outdoor work on a farm crossed by a transmission line.« less

Impact of Orientation on the Vitamin D Weighted Exposure of a Human in an Urban Environment.

PubMed

Schrempf, Michael; Thuns, Nadine; Lange, Kezia; Seckmeyer, Gunther

2017-08-16

The vitamin D₃-weighted UV exposure of a human with vertical posture was calculated for urban locations to investigate the impact of orientation and obstructions on the exposure. Human exposure was calculated by using the 3D geometry of a human and integrating the radiance, i.e., the radiant energy from the direct solar beam and the diffuse sky radiation from different incident and azimuth angles. Obstructions of the sky are derived from hemispherical images, which are recorded by a digital camera with a fisheye lens. Due to the low reflectivity of most surfaces in the UV range, the radiance from obstructed sky regions was neglected. For spring equinox (21 March), the exposure of a human model with winter clothing in an environment where obstructions cover 40% of the sky varies by up to 25%, depending on the orientation of the human model to the sun. The calculation of the accumulated vitamin D₃-weighted exposure of a human with winter clothing walking during lunch break shows that human exposure is reduced by the obstruction of buildings and vegetation by 40%.

Bisphenol A Exposure Disrupts Genomic Imprinting in the Mouse

PubMed Central

Susiarjo, Martha; Sasson, Isaac; Mesaros, Clementina; Bartolomei, Marisa S.

2013-01-01

Exposure to endocrine disruptors is associated with developmental defects. One compound of concern, to which humans are widely exposed, is bisphenol A (BPA). In model organisms, BPA exposure is linked to metabolic disorders, infertility, cancer, and behavior anomalies. Recently, BPA exposure has been linked to DNA methylation changes, indicating that epigenetic mechanisms may be relevant. We investigated effects of exposure on genomic imprinting in the mouse as imprinted genes are regulated by differential DNA methylation and aberrant imprinting disrupts fetal, placental, and postnatal development. Through allele-specific and quantitative real-time PCR analysis, we demonstrated that maternal BPA exposure during late stages of oocyte development and early stages of embryonic development significantly disrupted imprinted gene expression in embryonic day (E) 9.5 and 12.5 embryos and placentas. The affected genes included Snrpn, Ube3a, Igf2, Kcnq1ot1, Cdkn1c, and Ascl2; mutations and aberrant regulation of these genes are associated with imprinting disorders in humans. Furthermore, the majority of affected genes were expressed abnormally in the placenta. DNA methylation studies showed that BPA exposure significantly altered the methylation levels of differentially methylated regions (DMRs) including the Snrpn imprinting control region (ICR) and Igf2 DMR1. Moreover, exposure significantly reduced genome-wide methylation levels in the placenta, but not the embryo. Histological and immunohistochemical examinations revealed that these epigenetic defects were associated with abnormal placental development. In contrast to this early exposure paradigm, exposure outside of the epigenetic reprogramming window did not cause significant imprinting perturbations. Our data suggest that early exposure to common environmental compounds has the potential to disrupt fetal and postnatal health through epigenetic changes in the embryo and abnormal development of the placenta. PMID:23593014

HEDS - EPA DATABASE SYSTEM FOR PUBLIC ACCESS TO HUMAN EXPOSURE DATA

EPA Science Inventory

Human Exposure Database System (HEDS) is an Internet-based system developed to provide public access to human-exposure-related data from studies conducted by EPA's National Exposure Research Laboratory (NERL). HEDS was designed to work with the EPA Office of Research and Devel...

THE HUMAN EXPOSURE DATABASE SYSTEM (HEDS)-PUTTING THE NHEXAS DATA ON-LINE

EPA Science Inventory

The EPA's National Exposure Research Laboratory (NERL) has developed an Internet accessible Human Exposure Database System (HEDS) to provide the results of NERL human exposure studies to both the EPA and the external scientific communities. The first data sets that will be ava...

A paler shade of green? The toxicology of biodiesel emissions: Recent findings from studies with this alternative fuel.

PubMed

Madden, Michael C

2016-12-01

Biodiesel produced primarily from plants and algal feedstocks is believed to have advantages for production and use compared to petroleum and to some other fuel sources. There is some speculation that exposure to biodiesel combustion emissions may not induce biological responses or health effects or at a minimum reduce the effects relative to other fuels. In evaluating the overall environmental and health effects of biodiesel production to end use scenario, empirical data or modeling data based on such data are needed. This manuscript examines the available toxicology reports examining combustion derived biodiesel emissions since approximately 2007, when our last review of the topic occurred. Toxicity derived from other end uses of biodiesel - e.g., spills, dermal absorption, etc. - are not examined. Findings from biodiesel emissions are roughly divided into three areas: whole non-human animal model exposures; in vitro exposures of mammalian and bacterial cells (used for mutation studies primarily); and human exposures in controlled or other exposure fashions. Overall, these more current studies clearly demonstrate that biodiesel combustion emission exposure- to either 100% biodiesel or a blend in petroleum diesel- can induce biological effects. There are reports that show biodiesel exposure generally induces more effects or a greater magnitude of effect than petroleum diesel, however there are also a similar number of reports showing the opposite trend. It is unclear whether effects induced by exposure to a blend are greater than exposure to 100% biodiesel. Taken together, the evidence suggest biodiesel emissions can have some similar effects as diesel emissions on inflammatory, vascular, mutagenic, and other responses. While acute biodiesel exposures can show toxicity with a variety of endpoints, the potential effects on human health need further validation. Additionally there are few or no findings to date on whether biodiesel emissions can induce effects or even a weaker response that petroleum diesel with repeated exposure scenarios such as in an occupational setting. This article is part of a Special Issue entitled Air Pollution, edited by Wenjun Ding, Andrew J. Ghio and Weidong Wu. Copyright © 2016. Published by Elsevier B.V.

Anticoagulant rodenticides and wildlife: Introduction

USGS Publications Warehouse

van den Brink, Nico W.; Elliott, John E.; Shore, Richard F.; Rattner, Barnett A.; van den Brink, Nico W.; Elliott, John E.; Shore, Richard F.; Rattner, Barnett A.

2018-01-01

Rodents have interacted with people since the beginning of systematic food storage by humans in the early Neolithic era. Such interactions have had adverse outcomes such as threats to human health, spoiling and consumption of food sources, damage to human infrastructure and detrimental effects on indigenous island wildlife (through inadvertent anthropogenic assisted introductions). These socio/economic and environmental impacts illustrate the clear need to control populations of commensal rodents. Different methods have been applied historically but the main means of control in the last decades is through the application of rodenticides, mainly anticoagulant rodenticides (ARs) that inhibit blood clotting. The so-called First Generation Anticoagulant Rodenticides (FGARs) proved highly effective but rodents increasingly developed resistance. This led to a demand for more effective alternative compounds and paved the way to the development of Second Generation Anticoagulant Rodenticides (SGARs). These were more acutely toxic and persistent, making them more effective but also increasing the risks of exposure of non-target species and secondary poisoning of predatory species. SGARs often fail the environmental thresholds of different regulatory frameworks because of these negative side-effects, but their use is still permitted because of the overwhelming societal needs for rodent control and the lack of effective alternatives. This book provides a state-of-the-art overview of the scientific advancements in assessment of environmental exposure, effects and risks of currently used ARs. This is discussed in relation to the societal needs for rodent control, including risk mitigation and development of alternatives.

Geographical Clusters and Predictors of Rabies in Three Southeastern States.

PubMed

Reilly, Sara; Sanderson, Wayne T; Christian, W Jay; Browning, Steven R

2017-06-01

The rabies virus causes progressive encephalomyelitis that is fatal in nearly 100% of untreated cases. In the United States, wildlife act as the primary reservoir for rabies; prevention, surveillance, and control costs remain high. The purpose of this study is to understand the current distribution of wildlife rabies in three southeastern states, with particular focus on raccoons as the primary eastern reservoir, as well as identify demographic and geographic factors which may affect the risk of human exposure. This ecologic study obtained county-level rabies surveillance data from state health departments and the United States Department of Agriculture Wildlife services for North Carolina, Virginia, and West Virginia from 2010 to 2013. A spatial statistical analysis was performed to identify county clusters with high or low rates of raccoon rabies in the three states. Potential demographic and geographic factors associated with these varying rates of rabies were assessed using a multivariable negative binomial regression model. In North Carolina, raccoons constituted 50% of positive tests, in Virginia, 49%, and in West Virginia, 50%. Compared to persons residing in West Virginia counties, persons in North Carolina counties had 1.67 times the risk of exposure (p < 0.0001) to a rabid raccoon and those in Virginia counties had 1.82 times the risk of exposure (p < 0.0001) to a rabid raccoon. Compared to those counties where farmland makes up less than 17% of the total area, persons residing in counties with 17-28% farmland had a 32% increased risk of exposure to a rabid raccoon. In counties with 28-39% farmland, there was an 84% increased risk of exposure. State, rurality, and percent of area designated as farmland were the best predictors of risk of raccoon rabies exposure. Further research is needed to better understand the effect of the oral rabies vaccine program in controlling the risk of human exposure to raccoon rabies.

The prebiotics 3′Sialyllactose and 6′Sialyllactose diminish stressor-induced anxiety-like behavior and colonic microbiota alterations: evidence for effects on the gut-brain axis

PubMed Central

Tarr, Andrew J.; Galley, Jeffrey D.; Fisher, Sydney; Chichlowski, Maciej; Berg, Brian M.; Bailey, Michael T.

2015-01-01

There are extensive bidirectional interactions between the gut microbiota and the central nervous system (CNS), and studies demonstrate that stressor exposure significantly alters gut microbiota community structure. We tested whether oligosaccharides naturally found in high levels in human milk, which have been reported to impact brain development and enhance the growth of beneficial commensal microbes, would prevent stressor-induced alterations in gut microbial community composition and attenuate stressor-induced anxiety-like behavior. Mice were fed standard laboratory diet, or laboratory diet containing the human milk oligosaccharides 3′Sialyllactose (3′SL) or 6′Sialyllactose (6′SL) for two weeks prior to being exposed to either a social disruption stressor or a non-stressed control condition. Stressor exposure significantly changed the structure of the colonic mucosa-associated microbiota in control mice, as indicated by changes in beta diversity. The stressor resulted in anxiety-like behavior in both the light/dark preference and open field tests in control mice. This effect was associated with a reduction in immature neurons in the dentate gyrus as indicated by doublecortin (DCX) immunostaining. These effects were not evident in mice fed milk oligosaccharides; stressor exposure did not significantly change microbial community structure in mice fed 3′SL or 6′SL. In addition, 3′SL and 6′SL helped maintain normal behavior on tests of anxiety-like behavior and normal numbers of DCX+ immature neurons. These studies indicate that milk oligosaccharides support normal microbial communities and behavioral responses during stressor exposure, potentially through effects on the gut microbiota-brain axis. PMID:26144888

Sodium metavanadate exhibits carcinogenic tendencies in vitro in immortalized human bronchial epithelial cells.

PubMed

Passantino, Lisa; Muñoz, Alexandra B; Costa, Max

2013-10-01

Pentavalent vanadium compounds induce intracellular changes in vitro that are consistent with those of other carcinogenic substances. While there is no clear evidence that vanadium compounds cause cancer in humans, vanadium pentoxide causes lung cancer in rodents after long-term inhalation exposures and in turn IARC has categorized it as a group 2B possible human carcinogen. The goal of this study was to investigate the carcinogenicity of NaVO3 in the human immortalized bronchial epithelial cell line, Beas-2B. Cells were treated with 10 μM NaVO3 for 5 weeks, with or without recovery time, followed by gene expression microarray analysis. In a separate experiment, cells were exposed to 1-10 μM NaVO3 for 4 weeks and then grown in soft agar to test for anchorage-independent growth. A dose-dependent increase in the number of colonies was observed. In scratch tests, NaVO3-transformed clones could repair a wound faster than controls. In a gene expression microarray analysis of soft agar clones there were 2010 differentially expressed genes (DEG) (adjusted p-value ≤ 0.05) in NaVO3-transformed clones relative to control clones. DEG from this experiment were compared with the DEG of 5 week NaVO3 exposure with or without recovery, all with adjusted p-values < 0.05, and 469 genes were altered in the same direction for transformed clones, 5 week NaVO3-treated cells, and the recovered cells. The data from this study imply that chronic exposure to NaVO3 causes changes that are consistent with cellular transformation including anchorage-independent growth, enhanced migration ability, and gene expression changes that were likely epigenetically inherited.