Monitoring and reducing exposure of infants to pollutants in house dust.

PubMed

Roberts, John W; Wallace, Lance A; Camann, David E; Dickey, Philip; Gilbert, Steven G; Lewis, Robert G; Takaro, Tim K

2009-01-01

The health risks to babies from pollutants in house dust may be 100 times greater than for adults. The young ingest more dust and are up to ten times more vulnerable to such exposures. House dust is the main exposure source for infants to allergens, lead, and PBDEs, as well as a major source of exposure to pesticides, PAHs, Gram-negative bacteria, arsenic, cadmium, chromium, phthalates, phenols, and other EDCs, mutagens, and carcinogens. Median or upper percentile concentrations in house dust of lead and several pesticides and PAHs may exceed health-based standards in North America. Early contact with pollutants among the very young is associated with higher rates of chronic illness such as asthma, loss of intelligence, ADHD, and cancer in children and adults. The potential of infants, who live in areas with soil contaminated by automotive and industrial emissions, can be given more protection by improved home cleaning and hand washing. Babies who live in houses built before 1978 have a prospective need for protection against lead exposures; homes built before 1940 have even higher lead exposure risks. The concentration of pollutants in house dust may be 2-32 times higher than that found in the soil near a house. Reducing infant exposures, at this critical time in their development, may reduce lifetime health costs, improve early learning, and increase adult productivity. Some interventions show a very rapid payback. Two large studies provide evidence that home visits to reduce the exposure of children with poorly controlled asthma triggers may return more than 100% on investment in 1 yr in reduced health costs. The tools provided to families during home visits, designed to reduce dust exposures, included vacuum cleaners with dirt finders and HEPA filtration, allergy control bedding covers, high-quality door mats, and HEPA air filters. Infants receive their highest exposure to pollutants in dust at home, where they spend the most time, and where the family has the

Reducing uncertainty in risk modeling for methylmercury exposure

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

Ponce, R.; Egeland, G.; Middaugh, J.

The biomagnification and bioaccumulation of methylmercury in marine species represents a challenge for risk assessment related to the consumption of subsistence foods in Alaska. Because of the profound impact that food consumption advisories have on indigenous peoples seeking to preserve a way of life, there is a need to reduce uncertainty in risk assessment. Thus, research was initiated to reduce the uncertainty in assessing the health risks associated with the consumption of subsistence foods. Because marine subsistence foods typically contain elevated levels of methylmercury, preliminary research efforts have focused on methylmercury as the principal chemical of concern. Of particular interestmore » are the antagonistic effects of selenium on methylmercury toxicity. Because of this antagonism, methylmercury exposure through the consumption of marine mammal meat (with high selenium) may not be as toxic as comparable exposures through other sources of dietary intake, such as in the contaminated bread episode of Iraq (containing relatively low selenium). This hypothesis is supported by animal experiments showing reduced toxicity of methylmercury associated with marine mammal meat, by the antagonistic influence of selenium on methylmercury toxicity, and by negative clinical findings in adult populations exposed to methylmercury through a marine diet not subject to industrial contamination. Exploratory model development is underway to identify potential improvements and applications of current deterministic and probabilistic models, particularly by incorporating selenium as an antagonist in risk modeling methods.« less

Exposure to potential occupational asthmogens: prevalence data from the National Occupational Exposure Survey.

PubMed

de la Hoz, R E; Young, R O; Pedersen, D H

1997-02-01

Few data are available about the prevalence of occupational exposures to agents which can cause occupational asthma or aggravate preexisting asthma (asthmogens). Using potential occupational exposure data from the National Occupational Exposure Survey (NOES) of 1980-1983, we investigated the number of asthmogen exposures, asthmogen-exposure(s) per production worker, and unprotected occupational asthmogen exposures in different industries and occupations. Data for the entire United States were used to generate estimates of occupational exposure at two selected state and local levels. It was estimated that 7,864,000 workers in the surveyed industries were potentially exposed to one or more occupational asthmogen(s) in the United States. The average number of observed potential exposures per asthmogen-exposed worker was 4.4, and varied from 11.9, in the Water Transportation industry, to 1.2 in Local and Suburban transportation. The largest number of observed potential exposures was recorded in the Apparel and Other Finished Products (garment) industry. This work and further analyses using this approach are expected to contribute to a better understanding of the epidemiology of occupational asthma, and to serve as a guide to target future occupational asthma surveillance efforts.

Integrating chemical, toxicological and clinical research to assess the potential of reducing health risks associated with cigarette smoking through reducing toxicant emissions.

PubMed

McAdam, Kevin; Murphy, James; Eldridge, Alison; Meredith, Clive; Proctor, Christopher

2018-06-01

The concept of a risk continuum for tobacco and nicotine products has been proposed, which differentiates products according to their propensity to reduce toxicant exposure and risk. Cigarettes are deemed the most risky and medicinal nicotine the least. We assessed whether a Reduced-Toxicant Prototype (RTP) cigarette could sufficiently reduce exposure to toxicants versus conventional cigarettes to be considered a distinct category in the risk continuum. We present findings from both pre-clinical and clinical studies in order to examine the potential for reduced smoke toxicant emissions to lower health risks associated with cigarette smoking. We conclude that current toxicant reducing technologies are unable to reduce toxicant emissions sufficiently to manifest beneficial disease-relevant changes in smokers. These findings point to a minimum toxicant exposure standard that future potentially reduced risk products would need to meet to be considered for full biological assessment. The RTP met WHO TobReg proposed limits on cigarette toxicant emissions, however the absence of beneficial disease relevant changes in smokers after six months reduced toxicant cigarette use, does not provide evidence that these regulatory proposals will positively impact risks of smoking related diseases. Greater toxicant reductions, such as those that can be achieved in next generation products e.g. tobacco heating products and electronic cigarettes are likely to be necessary to clearly reduce risks compared with conventional cigarettes. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Anesthesia-related Carbon Monoxide Exposure: Toxicity and Potential Therapy

PubMed Central

Levy, Richard J.

2016-01-01

Exposure to carbon monoxide (CO) during general anesthesia can result from volatile anesthetic degradation by carbon dioxide absorbents as well as re-breathing of endogenously produced CO. Although adherence to the Anesthesia Patient Safety Foundation guidelines reduces the risk of CO poisoning, patients may still experience a sub-toxic CO exposure during low-flow anesthesia. The consequences of such exposures are relatively unknown. In contrast to the widely recognized toxicity of high CO concentrations, the biological activity of low concentration CO has recently been shown be cytoprotective. As such, low dose CO is being explored as a novel treatment for a variety of different diseases. Here we review the concept of anesthesia-related CO exposure, identify the sources of production, detail the mechanisms of overt CO toxicity, highlight the cellular effects of low dose CO, and discuss the potential therapeutic role for CO as a part of routine anesthetic management. PMID:27537758

Radically Reducing Radiation Exposure during Routine Medical Imaging

Cancer.gov

Exposure to radiation from medical imaging in the United States has increased dramatically. NCI and several partner organizations sponsored a 2011 summit to promote efforts to reduce radiation exposure from medical imaging.

46 CFR 197.545 - Program to reduce personal exposure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Program to reduce personal exposure. 197.545 Section 197.545 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Benzene § 197.545 Program to reduce personal exposure. (a) When...

46 CFR 197.545 - Program to reduce personal exposure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Program to reduce personal exposure. 197.545 Section 197.545 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Benzene § 197.545 Program to reduce personal exposure. (a) When...

46 CFR 197.545 - Program to reduce personal exposure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Program to reduce personal exposure. 197.545 Section 197.545 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Benzene § 197.545 Program to reduce personal exposure. (a) When...

46 CFR 197.545 - Program to reduce personal exposure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Program to reduce personal exposure. 197.545 Section 197.545 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Benzene § 197.545 Program to reduce personal exposure. (a) When...

46 CFR 197.545 - Program to reduce personal exposure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Program to reduce personal exposure. 197.545 Section 197.545 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Benzene § 197.545 Program to reduce personal exposure. (a) When...

Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

PubMed Central

Jung, Heejung S.; Grady, Michael L.; Victoroff, Tristan; Miller, Arthur L.

2017-01-01

Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50–75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants’ exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation. PMID:28781568

Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air.

PubMed

Jung, Heejung S; Grady, Michael L; Victoroff, Tristan; Miller, Arthur L

2017-07-01

Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO 2 ) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO 2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm 3 , although CO 2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO 2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm 3 . We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO 2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO 2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50-75% maintained lower CO 2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants' exposures to particulate matter and CO 2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO 2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO 2 accumulation.

Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

NASA Astrophysics Data System (ADS)

Jung, Heejung S.; Grady, Michael L.; Victoroff, Tristan; Miller, Arthur L.

2017-07-01

Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50-75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants' exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation.

Potential role of reduced environmental UV exposure as a driver of the current epidemic of atopic dermatitis.

PubMed

Thyssen, Jacob P; Zirwas, Matthew J; Elias, Peter M

2015-11-01

The basis for the sudden and dramatic increase in atopic dermatitis (AD) and related atopic diseases in the second half of the 20th century is unclear. The hygiene hypothesis proposes that the transition from rural to urban living leads to reduced childhood exposure to pathogenic microorganisms. Hence instead of having the normal TH1 bias and immune tolerance because of repeated exposure to pathogens, urban dwellers have TH2 cell immune activity and atopic disease in a more sterile environment. Various other environmental exposures have been implicated in the explosion of AD (and atopic disorders in general), including breast-feeding, tobacco smoking, alcohol consumption, and exposure to domesticated furry pets. Notably, the key role of a compromised barrier of neonatal skin as a predisposing factor in the development of childhood AD has recently been demonstrated. In this article we review the salubrious effects of suberythemogenic doses of UVB irradiation for the skin barrier. We then discuss how the lack of sufficient UVB exposure could have contributed to the rapid increase in the incidence of AD in developed countries. This hypothesis offers a separate but not competing partial explanation, which should be viewed as not discounting the role of the etiopathogenic factors that also could influence the prevalence of atopic disorders. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. All rights reserved.

Exposure-Reducing Behaviors Among Residents Living Near a Coal Ash Storage Site.

PubMed

Zierold, Kristina M; Sears, Clara G; Brock, Guy N

2016-10-01

Coal ash, a waste product generated from burning coal for energy, is composed of highly respirable particles containing heavy metals, radioactive elements, and polycylic aromatic hydrocarbons. Coal ash is stored in landfills and surface impoundments frequently located near neighborhoods. Fugitive dust from the storage sites exposes neighborhoods, affecting the health and welfare of residents. The research questions of interest were (1) are community members concerned about coal ash exposure from the storage site; (2) what, if any, behaviors do community members engage in to reduce exposure; and (3) do exposure reducing behaviors differ by level of concern about coal ash. A community-based mixed-methods approach was used. Focus groups (n = 26) were conducted in 2012, and a cross-sectional survey was administered in 2013 (n = 231). The majority of survey respondents (62%) worried "a lot" about being exposed to coal ash; however, most did not engage in exposure-reducing behaviors, such as wearing protective equipment when doing chores. Compared with respondents who worry "some, very little, or none," or responded "I don't know," respondents who worried "a lot" about being exposed to coal ash did more exposure-reducing behaviors outdoors (p < .001) and indoors (p = .01). For people living near environmental hazards, reducing exposure is a priority. Although challenging because of the chronic nature of exposure, some behaviors can be useful in reducing exposure, such as wearing a particle-specific respirator when mowing the lawn. Communities at risk for chronic exposure to environmental toxins could benefit from education about exposure-reducing behaviors. © 2015 Society for Public Health Education.

Trait and state anxiety reduce the mere exposure effect

PubMed Central

Ladd, Sandra L.; Gabrieli, John D. E.

2015-01-01

The mere exposure effect refers to an affective preference elicited by exposure to previously unfamiliar items. Although it is a well-established finding, its mechanism remains uncertain, with some positing that it reflects affective processes and others positing that it reflects perceptual or motor fluency with repeated items. Here we examined whether individual differences in trait and state anxiety, which have been associated with the experience of emotion, influence the mere exposure effect. Participants’ trait (Study 1) and state (Study 2) anxiety were characterized with the State-Trait Anxiety Inventory. Greater trait and state anxiety correlated with greater negative affect and lesser positive affect. In both experiments, greater anxiety was associated with a reduced mere exposure effect. Measures of fluency (response times at study and test) were unrelated to the mere exposure effect. These findings support the role of affective processes in the mere exposure effect, and offer a new insight into the nature of anxiety such that anxiety is associated with a reduced experience of positive affect typically associated with familiarity. PMID:26074851

Trait and state anxiety reduce the mere exposure effect.

PubMed

Ladd, Sandra L; Gabrieli, John D E

2015-01-01

The mere exposure effect refers to an affective preference elicited by exposure to previously unfamiliar items. Although it is a well-established finding, its mechanism remains uncertain, with some positing that it reflects affective processes and others positing that it reflects perceptual or motor fluency with repeated items. Here we examined whether individual differences in trait and state anxiety, which have been associated with the experience of emotion, influence the mere exposure effect. Participants' trait (Study 1) and state (Study 2) anxiety were characterized with the State-Trait Anxiety Inventory. Greater trait and state anxiety correlated with greater negative affect and lesser positive affect. In both experiments, greater anxiety was associated with a reduced mere exposure effect. Measures of fluency (response times at study and test) were unrelated to the mere exposure effect. These findings support the role of affective processes in the mere exposure effect, and offer a new insight into the nature of anxiety such that anxiety is associated with a reduced experience of positive affect typically associated with familiarity.

Reducing Underserved Children’s Exposure to Secondhand Smoke

PubMed Central

Collins, Bradley N.; Nair, Uma S.; Hovell, Melbourne F.; DiSantis, Katie I.; Jaffe, Karen; Tolley, Natalie; Wileyto, E. Paul; Audrain-McGovern, Janet

2015-01-01

Introduction Addressing maternal smoking and child secondhand smoke exposure is a public health priority. Standard care advice and self-help materials to help parents reduce child secondhand smoke exposure is not sufficient to promote change in underserved populations. We tested the efficacy of a behavioral counseling approach with underserved maternal smokers to reduce infant’s and preschooler’s secondhand smoke exposure. Design A two-arm randomized trial: experimental behavior counseling versus enhanced standard care (control). Assessment staff members were blinded. Setting/participants Three hundred randomized maternal smokers were recruited from low-income urban communities. Participants had a child aged <4 years exposed to two or more maternal cigarettes/day at baseline. Intervention Philadelphia Family Rules for Establishing Smokefree Homes (FRESH) included 16 weeks of counseling. Using a behavioral shaping approach within an individualized cognitive–behavioral therapy framework, counseling reinforced efforts to adopt increasingly challenging secondhand smoke exposure–protective behaviors with the eventual goal of establishing a smokefree home. Main outcome measures Primary outcomes were end-of-treatment child cotinine and reported secondhand smoke exposure (maternal cigarettes/day exposed). Secondary outcomes were end-of-treatment 7-day point-prevalence self-reported cigarettes smoked/day and bioverified quit status. Results Participation in FRESH behavioral counseling was associated with lower child cotinine (β= −0.18, p=0.03) and secondhand smoke exposure (β= −0.57, p=0.03) at end of treatment. Mothers in behavioral counseling smoked fewer cigarettes/day (β= –1.84, p=0.03) and had higher bioverified quit rates compared with controls (13.8% vs 1.9%, χ2=10.56, p<0.01). There was no moderating effect of other smokers living at home. Conclusions FRESH behavioral counseling reduces child secondhand smoke exposure and promotes smoking quit

RECENT ENHANCEMENTS TO THE DIETARY EXPOSURE POTENTIAL MODEL

EPA Science Inventory

Presentation describes recent enhancements & new applications of the Dietary Exposure Potential Model (DEPM), a model developed to assist in design & interpretation of dietary exposure measurements. Model is an interactive system that provides dietary exposure estimates using dat...

Improved intensifying screen reduces X-ray exposure

NASA Technical Reports Server (NTRS)

Buchanan, R. A.

1972-01-01

X-ray intensifying screen may make possible radiographic procedures where detection speed and X-ray tube power have been the limiting factors. Device will reduce total population exposure to harmful radiation in the United States.

Vestibular short-latency evoked potential abolished by low-frequency noise exposure in rats.

PubMed

Stewart, Courtney E; Kanicki, Ariane C; Altschuler, Richard A; King, W M

2018-02-01

The vestibular system plays a critical role in detection of head movements and is essential for normal postural control. Because of their anatomical proximity to the cochlea, the otolith organs are selectively exposed to sound pressure and are at risk for noise overstimulation. Clinical reports suggest a link between noise exposure and balance problems, but the structural and physiological basis for this linkage is not well understood. The goal of this study was to determine the effects of low-frequency noise (LFN) on the otolith organs by correlating changes in vestibular short-latency evoked potentials (VsEPs) with changes in saccular afferent endings following noise exposure. LFN exposure transiently abolished the VsEP and reduced the number of stained calyces within the sacculus. Although some recovery of the VsEP waveform could be observed within 3 days after noise, at 3 wk recovery was only partial in most animals, consistent with a reduced number of afferents with calyceal endings. These data show that a single intense noise exposure is capable of causing a vestibular deficit that appears to mirror the synaptic deficit associated with hidden hearing loss after noise-induced cochlear injury. NEW & NOTEWORTHY This is the first study to explore the effects of low-frequency high-intensity noise on vestibular short-latency evoked potential (VsEP) responses, which shows a linkage between attenuated noise-induced VsEPs and pathological changes to otolith organ afferents. This finding suggests a potential limitation of the VsEP for evaluation of vestibular dysfunction, since the VsEP measurement may assess the activity of a specific class rather than all afferents.

What is the potential for interventions designed to prevent violence against women to reduce children's exposure to violence? Findings from the SASA! study, Kampala, Uganda.

PubMed

Kyegombe, Nambusi; Abramsky, Tanya; Devries, Karen M; Michau, Lori; Nakuti, Janet; Starmann, Elizabeth; Musuya, Tina; Heise, Lori; Watts, Charlotte

2015-12-01

Intimate partner violence (IPV) and child maltreatment often co-occur in households and lead to negative outcomes for children. This article explores the extent to which SASA!, an intervention to prevent violence against women, impacted children's exposure to violence. Between 2007 and 2012 a cluster randomized controlled trial was conducted in Kampala, Uganda. An adjusted cluster-level intention to treat analysis, compares secondary outcomes in intervention and control communities at follow-up. Under the qualitative evaluation, 82 in-depth interviews were audio recorded at follow-up, transcribed verbatim, and analyzed using thematic analysis complemented by constant comparative methods. This mixed-methods article draws mainly on the qualitative data. The findings suggest that SASA! impacted on children's experience of violence in three main ways. First, quantitative data suggest that children's exposure to IPV was reduced. We estimate that reductions in IPV combined with reduced witnessing by children when IPV did occur, led to a 64% reduction in prevalence of children witnessing IPV in their home (aRR 0.36, 95% CI 0.06-2.20). Second, among couples who experienced reduced IPV, qualitative data suggests parenting and discipline practices sometimes also changed-improving parent-child relationships and for a few parents, resulting in the complete rejection of corporal punishment as a disciplinary method. Third, some participants reported intervening to prevent violence against children. The findings suggest that interventions to prevent IPV may also impact on children's exposure to violence, and improve parent-child relationships. They also point to potential synergies for violence prevention, an area meriting further exploration. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Applying a community resilience framework to examine household emergency planning and exposure-reducing behavior among residents of Louisiana's industrial corridor.

PubMed

Reams, Margaret A; Lam, Nina S N; Cale, Tabitha M; Hinton, Corrinthia M

2013-01-01

Residents facing environmental hazards can take steps to reduce their exposure risks, and these actions may be considered adaptations that can enhance the overall resilience of communities. Applying concepts from social-ecological resilience theory, the authors examine emergency planning and exposure-reducing behaviors among residents of the upper Industrial Corridor of Louisiana and explore the extent to which the behaviors are associated with key theoretical influences on community resilience: exposure, vulnerability, and the "adaptive capacity" of residents. The behaviors of interest are adoption of a household emergency plan in the case of acute exposure events (like chemical spills), and limiting outdoor activities in response to Air Quality Index reports, thus potentially reducing chronic exposure risks. Statistical analyses indicate that adaptive behaviors are associated both with greater exposure to hazards and confidence in one's knowledge and ability to reduce exposure risks. Thus, the study yields evidence that "adaptive capacity" is particularly relevant to understanding and encouraging household emergency planning. Residents who believe that they are well-informed about risk-reducing strategies, regardless of education or income, were found to be more likely to have adopted these measures. Evidence that knowledge and confidence levels are linked to adaptive behaviors is good news for those working in public education and outreach programs, as these are attitudes and skills that can be nurtured. While factors associated with exposure and vulnerability to hazards are difficult to change, knowledge of risk-reducing strategies and confidence in one's abilities to reduce exposure risks can be improved through well-designed public education efforts.

Occupational exposure to potentially infectious biological material in a dental teaching environment.

PubMed

Machado-Carvalhais, Helenaura P; Ramos-Jorge, Maria L; Auad, Sheyla M; Martins, Laura H P M; Paiva, Saul M; Pordeus, Isabela A

2008-10-01

The aims of this cross-sectional study were to determine the prevalence of occupational accidents with exposure to biological material among undergraduate students of dentistry and to estimate potential risk factors associated with exposure to blood. Data were collected through a self-administered questionnaire (86.4 percent return rate), which was completed by a sample of 286 undergraduate dental students (mean age 22.4 +/-2.4 years). The students were enrolled in the clinical component of the curriculum, which corresponds to the final six semesters of study. Descriptive, bivariate, simple logistic regression and multiple logistic regression (Forward Stepwise Procedure) analyses were performed. The level of statistical significance was set at 5 percent. Percutaneous and mucous exposures to potentially infectious biological material were reported by 102 individuals (35.6 percent); 26.8 percent reported the occurrence of multiple episodes of exposure. The logistic regression analyses revealed that the incomplete use of individual protection equipment (OR=3.7; 95 percent CI 1.5-9.3), disciplines where surgical procedures are carried out (OR=16.3; 95 percent CI 7.1-37.2), and handling sharp instruments (OR=4.4; 95 percent CI 2.1-9.1), more specifically, hollow-bore needles (OR=6.8; 95 percent CI 2.1-19.0), were independently associated with exposure to blood. Policies of reviewing the procedures during clinical practice are recommended in order to reduce occupational exposure.

Reducing prenatal phthalate exposure through maternal dietary changes: results from a pilot study

PubMed Central

Barrett, Emily S.; Velez, Marissa; Qiu, Xing; Chen, Shaw-Ree

2016-01-01

Objectives Diet is a major source of exposure to certain phthalates, a class of environmental chemicals associated with endocrine disruption in animal models and humans. Several studies have attempted to lower phthalate exposure through carefully designed dietary interventions, with inconsistent results. We conducted a dietary intervention pilot study with the objective to lower phthalate exposure in low-income pregnant women, a particularly vulnerable population. Methods Ten pregnant women consumed a provided diet consisting of mostly fresh, organic foods for three days. We collected urine samples before, during, and after the intervention and conducted semi-structured interviews to assess the feasibility and acceptability of the intervention. We used repeated measures ANOVA and paired t-tests to assess differences in urinary phthalate metabolite concentrations across the study, focusing on the metabolites of di-2-ethylhexyl phthalate (DEHP), a phthalate of particular interest, and their molar sum (∑DEHP). Results Phthalate metabolite concentrations did not change appreciably during the intervention period. We observed no significant difference in ∑DEHP metabolite concentrations across the three time periods (F=0.21; adjusted p-value=0.65), and no reduction during the intervention as compared to baseline (t=−1.07, adjusted p-value=0.51). Results of interviews indicated that participants were not motivated to make dietary changes to potentially reduce chemical exposures outside of the study. Conclusions Despite the small sample size, our results suggest that promoting dietary changes to lower phthalate exposure may not be an effective public health measure. Reducing the use of phthalates in food processing and packaging may be a better solution to lowering exposure on a population level. PMID:25652062

Potential exposures and risks from beryllium-containing products.

PubMed

Willis, Henry H; Florig, H Keith

2002-10-01

Beryllium is the strongest of the lightweight metals. Used primarily in military applications prior to the end of the Cold War, beryllium is finding new applications in many commercial products, including computers, telecommunication equipment, and consumer and automotive electronics. The use of beryllium in nondefense consumer applications is of concern because beryllium is toxic. Inhalation of beryllium dust or vapor causes a chronic lung disease in some individuals at concentrations as low as 0.01 microg/m3 in air. As beryllium enters wider commerce, it is prudent to ask what risks this might present to the general public and to workers downstream of the beryllium materials industry. We address this question by evaluating the potential for beryllium exposure from the manufacturing, use, recycle, and disposal of beryllium-containing products. Combining a market study with a qualitative exposure analysis, we determine which beryllium applications and life cycle phases have the largest exposure potential. Our analysis suggests that use and maintenance of the most common types of beryllium-containing products do not result in any obvious exposures of concern, and that maintenance activities result in greater exposures than product use. Product disposal has potential to present significant individual risks, but uncertainties concerning current and future routes of product disposal make it difficult to be definitive. Overall, additional exposure and dose-response data are needed to evaluate both the health significance of many exposure scenarios, and the adequacy of existing regulations to protect workers and the public. Although public exposures to beryllium and public awareness and concern regarding beryllium risks are currently low, beryllium risks have psychometric qualities that may lead to rapidly heightened public concern.

Applying a community resilience framework to examine household emergency planning and exposure-reducing behavior among residents of Louisiana’s industrial corridor

PubMed Central

Reams, Margaret A.; Lam, Nina S.N.; Cale, Tabitha M.; Hinton, Corrinthia M.

2014-01-01

Residents facing environmental hazards can take steps to reduce their exposure risks, and these actions may be considered adaptations that can enhance the overall resilience of communities. Applying concepts from social-ecological resilience theory, the authors examine emergency planning and exposure-reducing behaviors among residents of the upper Industrial Corridor of Louisiana, and explore the extent to which the behaviors are associated with key theoretical influences on community resilience: exposure, vulnerability, and the “adaptive capacity” of residents. The behaviors of interest are adoption of a household emergency plan in the case of acute exposure events (like chemical spills), and limiting outdoor activities in response to Air-Quality Index (AQI) reports, thus potentially reducing chronic exposure risks. Statistical analyses indicate that adaptive behaviors are associated both with greater exposure to hazards and confidence in one’s knowledge and ability to reduce exposure risks. Thus, the study yields evidence that “adaptive capacity” is particularly relevant to understanding and encouraging household emergency planning. Residents who believe that they are well-informed about risk-reducing strategies, regardless of education or income, were found to be more likely to have adopted these measures. Evidence that knowledge and confidence levels are linked to adaptive behaviors is good news for those working in public education and outreach programs, as these are attitudes and skills that can be nurtured. While factors associated with exposure and vulnerability to hazards are difficult to change, knowledge of risk-reducing strategies and confidence in one’s abilities to reduce exposure risks can be improved through well-designed public education efforts. PMID:24180091

Simple methods to reduce patient exposure during scoliosis radiography

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

Butler, P.F.; Thomas, A.W.; Thompson, W.E.

1986-05-01

Radiation exposure to the breasts of adolescent females can be reduced significantly through the use of one or all of the following methods: fast, rare-earth screen-film combinations; specially designed compensating filters; and breast shielding. The importance of exposure reduction during scoliosis radiography as well as further details on the above described methods are discussed. In addition, the early results of a Center for Devices and Radiological Health study, which recorded exposure and technique data for scoliosis radiography, is presented.

Appearance-based interventions to reduce UV exposure: A systematic review.

PubMed

Persson, Sofia; Benn, Yael; Dhingra, Katie; Clark-Carter, David; Owen, Alison L; Grogan, Sarah

2018-05-01

As a majority of skin cancer cases are behaviourally preventable, it is crucial to develop effective strategies to reduce UV exposure. Health-focused interventions have not proved to be sufficiently effective, and it has been suggested that people might be more susceptible to information about the negative effects of the sun on their appearance. This systematic review of 30 separate papers, reporting 33 individual studies published between 2005 and 2017, assesses the overall effectiveness of appearance interventions on participants' UV exposure and sun protection behaviour. Appearance-based interventions have positive effects on sun exposure and sun protection, immediately after the intervention as well as up to 12 months afterwards. The meta-analysis found a medium effect size on sun protection intentions for interventions which combined UV photography and photoageing information: r +  = .424; k = 3, N = 319, CI = 0.279-0.568, p = .023. This review provides a current perspective on the effectiveness of appearance-based interventions to reduce UV exposure, and also highlights methodological issues. It recommends that practitioners administer a UV photo intervention in combination with photoageing information to reduce UV exposure. Furthermore, the review specifically recommends that future research focuses on the use of theoretical constructs to enhance photoageing information and is conducted with older participants and in countries where people have less opportunity for sun exposure. Statement of contribution What is already known on this subject? Appearance-focused interventions may in some cases be more effective than health-focused interventions in reducing UV exposure, as the underlying motivations for tanning are associated with appearance concerns. Previous reviews and meta-analyses have indicated that appearance-focused interventions such as photoageing and UV photo are associated with positive effects in reducing UV exposure and/or increasing

Recirculating Air Filtration Significantly Reduces Exposure to Airborne Nanoparticles

PubMed Central

Pui, David Y.H.; Qi, Chaolong; Stanley, Nick; Oberdörster, Günter; Maynard, Andrew

2008-01-01

Background Airborne nanoparticles from vehicle emissions have been associated with adverse effects in people with pulmonary and cardiovascular disease, and toxicologic studies have shown that nanoparticles can be more hazardous than their larger-scale counterparts. Recirculating air filtration in automobiles and houses may provide a low-cost solution to reducing exposures in many cases, thus reducing possible health risks. Objectives We investigated the effectiveness of recirculating air filtration on reducing exposure to incidental and intentionally produced airborne nanoparticles under two scenarios while driving in traffic, and while generating nanomaterials using gas-phase synthesis. Methods We tested the recirculating air filtration in two commercial vehicles when driving in traffic, as well as in a nonventilation room with a nanoparticle generator, simulating a nanomaterial production facility. We also measured the time-resolved aerosol size distribution during the in-car recirculation to investigate how recirculating air filtration affects particles of different sizes. We developed a recirculation model to describe the aerosol concentration change during recirculation. Results The use of inexpensive, low-efficiency filters in recirculation systems is shown to reduce nanoparticle concentrations to below levels found in a typical office within 3 min while driving through heavy traffic, and within 20 min in a simulated nanomaterial production facility. Conclusions Development and application of this technology could lead to significant reductions in airborne nanoparticle exposure, reducing possible risks to health and providing solutions for generating nanomaterials safely. PMID:18629306

Reducing chemical exposures at home: opportunities for action

PubMed Central

Zota, Ami R; Singla, Veena; Adamkiewicz, Gary; Mitro, Susanna D; Dodson, Robin E

2017-01-01

Indoor environments can influence human environmental chemical exposures and, ultimately, public health. Furniture, electronics, personal care and cleaning products, floor coverings and other consumer products contain chemicals that can end up in the indoor air and settled dust. Consumer product chemicals such as phthalates, phenols, flame retardants and per- and polyfluorinated alkyl substances are widely detected in the US general population, including vulnerable populations, and are associated with adverse health effects such as reproductive and endocrine toxicity. We discuss the implications of our recent meta-analysis describing the patterns of chemical exposures and the ubiquity of multiple chemicals in indoor environments. To reduce the likelihood of exposures to these toxic chemicals, we then discuss approaches for exposure mitigation: targeting individual behaviour change, household maintenance and purchasing decisions, consumer advocacy and corporate responsibility in consumer markets, and regulatory action via state/federal policies. There is a need to further develop evidence-based strategies for chemical exposure reduction in each of these areas, given the multi-factorial nature of the problem. Further identifying those at greatest risk; understanding the individual, household and community factors that influence indoor chemical exposures; and developing options for mitigation may substantially improve individuals’ exposures and health. PMID:28756396

Surveillance methods for identifying, characterizing, and monitoring tobacco products: potential reduced exposure products as an example

PubMed Central

O’Connor, Richard J.; Cummings, K. Michael; Rees, Vaughan W.; Connolly, Gregory N.; Norton, Kaila J.; Sweanor, David; Parascandola, Mark; Hatsukami, Dorothy K.; Shields, Peter G.

2015-01-01

Tobacco products are widely sold and marketed, yet integrated data systems for identifying, tracking, and characterizing products are lacking. Tobacco manufacturers recently have developed potential reduction exposure products (PREPs) with implied or explicit health claims. Currently, a systematic approach for identifying, defining, and evaluating PREPs sold at the local, state or national levels in the US has not been developed. Identifying, characterizing, and monitoring new tobacco products could be greatly enhanced with a responsive surveillance system. This paper critically reviews available surveillance data sources for identifying and tracking tobacco products, including PREPs, evaluating strengths and weaknesses of potential data sources in light of their reliability and validity. Absent regulations mandating disclosure of product-specific information, it is likely that public health officials will need to rely on a variety of imperfect data sources to help identify, characterize, and monitor tobacco products, including PREPs. PMID:19959680

Reducing attenuation in exposure-response relationships by exposure modeling and grouping: the relationship between wood dust exposure and lung function.

PubMed

Teschke, Kay; Spierings, Judith; Marion, Stephen A; Demers, Paul A; Davies, Hugh W; Kennedy, Susan M

2004-12-01

In a study of wood dust exposure and lung function, we tested the effect on the exposure-response relationship of six different exposure metrics using the mean measured exposure of each subject versus the mean exposure based on various methods of grouping subjects, including job-based groups and groups based on an empirical model of the determinants of exposure. Multiple linear regression was used to examine the association between wood dust concentration and forced expiratory volume in 1s (FEV(1)), adjusting for age, sex, height, race, pediatric asthma, and smoking. Stronger point estimates of the exposure-response relationships were observed when exposures were based on increasing levels of aggregation, allowing the relationships to be found statistically significant in four of the six metrics. The strongest point estimates were found when exposures were based on the determinants of exposure model. Determinants of exposure modeling offers the potential for improvement in risk estimation equivalent to or beyond that from job-based exposure grouping.

Reduced foodborne toxin exposure is a benefit of improving dietary diversity.

PubMed

Wu, Felicia; Mitchell, Nicole J; Male, Denis; Kensler, Thomas W

2014-10-01

Naturally occurring foodborne toxins are common in subsistence diets of low-income human populations worldwide. Often, these populations rely on one or two staple foods for the bulk of their calories, making them more susceptible to chronic intake of certain toxins. Exposure to common foodborne toxins is associated with diverse conditions such as cancer, immunotoxicity, growth impairment, and neurological deficits. Interventions focused solely on reducing toxin levels have proven difficult to sustain. Using case studies of two foodborne toxins, aflatoxin and cassava cyanide, this article addresses the heightened risk of particular diseases from eating monotonous diets based in maize, groundnuts, and cassava: common in sub-Saharan Africa and parts of Asia. We also discuss the potential role of increased dietary diversity in counteracting these diseases. Increased dietary diversity can reduce consumption of toxins and increase intake of nutrients that could counteract the toxicity of such chemicals. In Qidong, China, a population that previously consumed a monotonous maize-based diet and increased dietary diversity since the 1980s has experienced a dramatic reduction in liver cancer mortalities. That liver cancer decreased as dietary diversity increased is the catalyst for the hypothesis that dietary diversity could have a direct impact on reducing health effects of foodborne toxins. Future research, agricultural development, and food policy reforms should take into consideration the multifaceted benefits associated with improved dietary diversity. Collaborations between toxicologists, nutritionists, and policymakers are important to development of sustainable interventions to reduce foodborne toxin exposure and promote health through increased dietary diversity. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Reducing placebo exposure in trials: Considerations from the Research Roundtable in Epilepsy.

PubMed

Fureman, Brandy E; Friedman, Daniel; Baulac, Michel; Glauser, Tracy; Moreno, Jonathan; Dixon-Salazar, Tracy; Bagiella, Emilia; Connor, Jason; Ferry, Jim; Farrell, Kathleen; Fountain, Nathan B; French, Jacqueline A

2017-10-03

The randomized controlled trial is the unequivocal gold standard for demonstrating clinical efficacy and safety of investigational therapies. Recently there have been concerns raised about prolonged exposure to placebo and ineffective therapy during the course of an add-on regulatory trial for new antiepileptic drug approval (typically ∼6 months in duration), due to the potential risks of continued uncontrolled epilepsy for that period. The first meeting of the Research Roundtable in Epilepsy on May 19-20, 2016, focused on "Reducing placebo exposure in epilepsy clinical trials," with a goal of considering new designs for epilepsy regulatory trials that may be added to the overall development plan to make it, as a whole, safer for participants while still providing rigorous evidence of effect. This topic was motivated in part by data from a meta-analysis showing a 3- to 5-fold increased rate of sudden unexpected death in epilepsy in participants randomized to placebo or ineffective doses of new antiepileptic drugs. The meeting agenda included rationale and discussion of different trial designs, including active-control add-on trials, placebo add-on to background therapy with adjustment, time to event designs, adaptive designs, platform trials with pooled placebo control, a pharmacokinetic/pharmacodynamic approach to reducing placebo exposure, and shorter trials when drug tolerance has been ruled out. The merits and limitations of each design were discussed and are reviewed here. © 2017 American Academy of Neurology.

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.

Potential Exposures to Australian Bat Lyssavirus Notified in Queensland, Australia, 2009-2014.

PubMed

Si, Damin; Marquess, John; Donnan, Ellen; Harrower, Bruce; McCall, Bradley; Bennett, Sonya; Lambert, Stephen

2016-12-01

Australian bat lyssavirus (ABLV) belongs to the genus Lyssavirus which also includes classic rabies virus and the European lyssaviruses. To date, the only three known human ABLV cases, all fatal, have been reported from Queensland, Australia. ABLV is widely distributed in Australian bats, and any bite or scratch from an Australian bat is considered a potential exposure to ABLV. Potential exposure to ABLV has been a notifiable condition in Queensland since 2005. We analysed notification data for potential exposures occurring between 2009 and 2014. There were 1,515 potential exposures to ABLV notified in Queensland, with an average annual notification rate of 5.6 per 100,000 population per year. The majority of notified individuals (96%) were potentially exposed to ABLV via bats, with a small number of cases potentially exposed via two ABLV infected horses and an ABLV infected human. The most common routes of potential exposure were through bat scratches (47%) or bites (37%), with less common routes being mucous membrane/broken skin exposure to bat saliva/brain tissue (2.2%). Intentional handling of bats by the general public was the major cause of potential exposures (56% of notifications). Examples of these potential exposures included people attempting to rescue bats caught in barbed wire fences/fruit tree netting, or attempting to remove bats from a home. Following potential exposures, 1,399 cases (92%) were recorded as having appropriate post-exposure prophylaxis (PEP) as defined in national guidelines, with the remainder having documentation of refusal or incomplete PEP. Up to a quarter of notifications occurred after two days from the potential exposure, but with some delays being more than three weeks. Of 393 bats available for testing during the reporting period, 20 (5.1%) had ABLV detected, including four species of megabats (all flying foxes) and one species of microbats (yellow-bellied sheathtail bat). Public health strategies should address the strong

Comparison of modeling approaches to prioritize chemicals based on estimates of exposure and exposure potential.

PubMed

Mitchell, Jade; Arnot, Jon A; Jolliet, Olivier; Georgopoulos, Panos G; Isukapalli, Sastry; Dasgupta, Surajit; Pandian, Muhilan; Wambaugh, John; Egeghy, Peter; Cohen Hubal, Elaine A; Vallero, Daniel A

2013-08-01

While only limited data are available to characterize the potential toxicity of over 8 million commercially available chemical substances, there is even less information available on the exposure and use-scenarios that are required to link potential toxicity to human and ecological health outcomes. Recent improvements and advances such as high throughput data gathering, high performance computational capabilities, and predictive chemical inherency methodology make this an opportune time to develop an exposure-based prioritization approach that can systematically utilize and link the asymmetrical bodies of knowledge for hazard and exposure. In response to the US EPA's need to develop novel approaches and tools for rapidly prioritizing chemicals, a "Challenge" was issued to several exposure model developers to aid the understanding of current systems in a broader sense and to assist the US EPA's effort to develop an approach comparable to other international efforts. A common set of chemicals were prioritized under each current approach. The results are presented herein along with a comparative analysis of the rankings of the chemicals based on metrics of exposure potential or actual exposure estimates. The analysis illustrates the similarities and differences across the domains of information incorporated in each modeling approach. The overall findings indicate a need to reconcile exposures from diffuse, indirect sources (far-field) with exposures from directly, applied chemicals in consumer products or resulting from the presence of a chemical in a microenvironment like a home or vehicle. Additionally, the exposure scenario, including the mode of entry into the environment (i.e. through air, water or sediment) appears to be an important determinant of the level of agreement between modeling approaches. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparison of modeling approaches to prioritize chemicals based on estimates of exposure and exposure potential

PubMed Central

Mitchell, Jade; Arnot, Jon A.; Jolliet, Olivier; Georgopoulos, Panos G.; Isukapalli, Sastry; Dasgupta, Surajit; Pandian, Muhilan; Wambaugh, John; Egeghy, Peter; Cohen Hubal, Elaine A.; Vallero, Daniel A.

2014-01-01

While only limited data are available to characterize the potential toxicity of over 8 million commercially available chemical substances, there is even less information available on the exposure and use-scenarios that are required to link potential toxicity to human and ecological health outcomes. Recent improvements and advances such as high throughput data gathering, high performance computational capabilities, and predictive chemical inherency methodology make this an opportune time to develop an exposure-based prioritization approach that can systematically utilize and link the asymmetrical bodies of knowledge for hazard and exposure. In response to the US EPA’s need to develop novel approaches and tools for rapidly prioritizing chemicals, a “Challenge” was issued to several exposure model developers to aid the understanding of current systems in a broader sense and to assist the US EPA’s effort to develop an approach comparable to other international efforts. A common set of chemicals were prioritized under each current approach. The results are presented herein along with a comparative analysis of the rankings of the chemicals based on metrics of exposure potential or actual exposure estimates. The analysis illustrates the similarities and differences across the domains of information incorporated in each modeling approach. The overall findings indicate a need to reconcile exposures from diffuse, indirect sources (far-field) with exposures from directly, applied chemicals in consumer products or resulting from the presence of a chemical in a microenvironment like a home or vehicle. Additionally, the exposure scenario, including the mode of entry into the environment (i.e. through air, water or sediment) appears to be an important determinant of the level of agreement between modeling approaches. PMID:23707726

Efforts to reduce exposure at Japanese PWRs: CVCS improvement

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

Terada, Ryosuke

1995-03-01

Many reports have been focused on the reduction of radiation sources and related occupational exposures. The radiation sources mainly consist of corrosion products. Radiation dose rate is determined by the amount of the activated corrosion products on the surface of the primary loop components of Pressurized Water Reactor (PWR) plants. Therefore, reducing the amount of the corrosion product will contribute to the reduction of occupational exposures. In order to reduce the corrosion products, Chemical and Volume Control System (CVCS) has been improved in Japanese PWRs as follows: (a) Cation Bed Demineralizer Flowrate Control; (b) Hydrogen Peroxide Injection System; (c) Purificationmore » Flowrate During Plant Shutdown; (d) Fine Mesh Filters Upstream of Mixed Bed Demineralizers.« less

Cooking fish is not effective in reducing exposure to perfluoroalkyl and polyfluoroalkyl substances.

PubMed

Bhavsar, Satyendra P; Zhang, Xianming; Guo, Rui; Braekevelt, Eric; Petro, Steve; Gandhi, Nilima; Reiner, Eric J; Lee, Holly; Bronson, Roni; Tittlemier, Sheryl A

2014-05-01

Consumption of fish is considered a part of a healthy diet; however, health risks from fish consumption exist due to potential exposure to various contaminants accumulated in fish. Cooking fish can reduce exposure to many organic chemicals in fish. Similar results have been presented for low levels of perfluoroalkyl and polyfluoroalkyl substances (PFASs), a class of contaminants of emerging concern, in grocery store fish. We examined the effectiveness of three cooking methods (i.e., baking, broiling, and frying) on reducing PFAS levels in four sport fish species. Samples of Chinook salmon, common carp, lake trout and walleye were collected from four rivers in Ontario, Canada and skin-off fillets were analyzed for regular groups of PFASs such as perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs), as well as perfluoroalkyl phosphonic acids (PFPAs), perfluoroalkyl phosphinic acids (PFPIAs) and polyfluoroalkyl phosphoric acid diesters (diPAPs), which are PFASs of emerging concern. Perfluorooctane sulfonate (PFOS) was the dominant PFAS detected and the concentrations were more than an order of magnitude higher than those reported for fish from grocery stores in Canada, Spain, and China. Although concentrations of PFOS in fish fillets generally increase after cooking, amounts of PFOS largely remain unchanged. Relatively minor differences in changes in the fish PFAS amounts after cooking depended on fish species and cooking method used. We conclude that cooking sport fish is generally not an effective approach to reduce dietary exposure to PFASs, especially PFOS. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Reducing personal exposure to particulate air pollution improves cardiovascular health in patients with coronary heart disease.

PubMed

Langrish, Jeremy P; Li, Xi; Wang, Shengfeng; Lee, Matthew M Y; Barnes, Gareth D; Miller, Mark R; Cassee, Flemming R; Boon, Nicholas A; Donaldson, Ken; Li, Jing; Li, Liming; Mills, Nicholas L; Newby, David E; Jiang, Lixin

2012-03-01

Air pollution exposure increases cardiovascular morbidity and mortality and is a major global public health concern. We investigated the benefits of reducing personal exposure to urban air pollution in patients with coronary heart disease. In an open randomized crossover trial, 98 patients with coronary heart disease walked on a predefined route in central Beijing, China, under different conditions: once while using a highly efficient face mask, and once while not using the mask. Symptoms, exercise, personal air pollution exposure, blood pressure, heart rate, and 12-lead electrocardiography were monitored throughout the 24-hr study period. Ambient air pollutants were dominated by fine and ultrafine particulate matter (PM) that was present at high levels [74 μg/m³ for PM(2.5) (PM with aerodynamic diamater <2.5 µm)]. Consistent with traffic-derived sources, this PM contained organic carbon and polycyclic aromatic hydrocarbons and was highly oxidizing, generating large amounts of free radicals. The face mask was well tolerated, and its use was associated with decreased self-reported symptoms and reduced maximal ST segment depression (-142 vs. -156 μV, p = 0.046) over the 24-hr period. When the face mask was used during the prescribed walk, mean arterial pressure was lower (93 ± 10 vs. 96 ± 10 mmHg, p = 0.025) and heart rate variability increased (high-frequency power: 54 vs. 40 msec², p = 0.005; high-frequency normalized power: 23.5 vs. 20.5 msec, p = 0.001; root mean square successive differences: 16.7 vs. 14.8 msec, p = 0.007). However, mask use did not appear to influence heart rate or energy expenditure. Reducing personal exposure to air pollution using a highly efficient face mask appeared to reduce symptoms and improve a range of cardiovascular health measures in patients with coronary heart disease. Such interventions to reduce personal exposure to PM air pollution have the potential to reduce the incidence of cardiovascular events in this highly

Pure versus guided mirror exposure to reduce body dissatisfaction: a preliminary study with university women.

PubMed

Moreno-Domínguez, Silvia; Rodríguez-Ruiz, Sonia; Fernández-Santaella, M Carmen; Jansen, Anita; Tuschen-Caffier, Brunna

2012-03-01

While effectiveness of mirror exposure to reduce body dissatisfaction has been demonstrated, the exposure was almost always combined with other interventions. The aim of the study was to evaluate the effectiveness of a pure mirror exposure intervention compared with a guided mirror exposure (participants are guided to describe their body shape in a non-evaluative manner) and an imagery exposure intervention (participants are guided to describe their body through mental representation). Thirty-one women with high body dissatisfaction received five sessions of treatment under one of the three conditions. All interventions reduced body dissatisfaction, but only the mirror exposures successfully reduced the frequency of negative thoughts and feelings of ugliness. Pure mirror exposure was more effective than guided exposure for reducing body discomfort within and between sessions. Pure mirror exposure, based on the traditional extinction paradigm, led to strong emotional activation followed by a fast decrease in emotional reactivity. Copyright © 2011 Elsevier Ltd. All rights reserved.

Visible light exposure reduces the drip loss of fresh-cut watermelon.

PubMed

Wang, Yubin; Li, Wu; Cai, Wenqian; Ma, Yue; Xu, Yong; Zhao, Xiaoyan; Zhang, Chao

2018-05-01

Drip loss of fresh-cut watermelon has become a concern for both producers and consumers. The effect of visible light exposure on the drip loss of fresh-cut watermelon was evaluated. Visible light treatments of 3000 and 10 Lux were applied to fresh-cut watermelon at 4 °C during the shelf life for 5 days, with light exposure of 150 Lux as the control. The drip loss of the fresh-cut watermelon at 3000 Lux was 74.8% of that at 150 Lux on the fifth day, and the moisture evaporation at 3000 Lux was 1.89 times that at 150 Lux. Moreover, the light exposure of 3000 Lux reduced the activity of polygalacturonase, which is a key hydrolase related to cell wall degradation. The cell wall degradation ratio of the fresh-cut watermelon at 3000 Lux was 81.7% of that at 150 Lux on the fifth day. Overall, light exposure of 3000 Lux reduced drip loss by accelerating moisture evaporation in fresh-cut watermelon, as well as by reducing the activity of polygalacturonase and the ratio of cell wall degradation. Hence, exposing the fresh-cut watermelon to visible light of 3000 Lux during the shelf life was a feasible way of reducing drip loss.

Potential Impacts of Modifiable Behavioral and Environmental Exposures on Reducing Burden of Under-five Mortality Associated with Household Air Pollution in Nepal.

PubMed

Naz, Sabrina; Page, Andrew; Agho, Kingsley Emwinyore

2018-01-01

Objectives Household air pollution (HAP) is one of the leading causes of respiratory illness and deaths among young children in low and lower-middle income countries. This study examines for the first time trends in the association between HAP from cooking fuel and under-five mortality and measures the potential impact of interventions to reduce HAP using Nepal Demographic and Health Survey datasets (2001-2011). Methods A total of 17,780 living children across four age-groups (neonatal 0-28 days, post-neonatal 1-11 months, child 12-59 months and under-five 0-59 months) were included and multi-level logistic regression models were used for analyses. Population attributable fractions of key risk factors and potential impact fractions assessing the impact of previous interventions to reduce exposure prevalence were also calculated. Results Use of cooking fuel was associated with total under-five mortality (OR 2.19, 95% CI 1.37-3.51, P = 0.001) in Nepal, with stronger associations evident for sub-group analyses of neonatal mortality (OR 2.67, 95% CI 1.47-4.82, P = 0.001). Higher association was found in rural areas and for households without a separate kitchen using polluting fuel for cooking, and in women who had never breastfed for all age-groups of children. PIF estimates, assuming a 63% of reduction of HAP based on previously published interventions in Nepal, suggested that a burden of 40% of neonatal and 33% of under-five mortality cases associated with an indoor kitchen using polluting fuel could be avoidable. Conclusion Improved infrastructure and behavioral interventions could help reduce the pollution from cooking fuel in the household resulting in further reduction in under-five mortality in Nepal.

Reducing health risks from indoor exposures in rapidly developing urban China.

PubMed

Zhang, Yinping; Mo, Jinhan; Weschler, Charles J

2013-07-01

Over the past two decades there has been a large migration of China's population from rural to urban regions. At the same time, residences in cities have changed in character from single-story or low-rise buildings to high-rise structures constructed and furnished with many synthetic materials. As a consequence, indoor exposures (to pollutants with outdoor and indoor sources) have changed significantly. We briefly discuss the inferred impact that urbanization and modernization have had on indoor exposures and public health in China. We argue that growing adverse health costs associated with these changes are not inevitable, and we present steps that could be taken to reduce indoor exposures to harmful pollutants. As documented by China's Ministry of Health, there have been significant increases in morbidity and mortality among urban residents over the past 20 years. Evidence suggests that the population's exposure to air pollutants has contributed to increases in lung cancer, cardiovascular disease, pulmonary disease, and birth defects. Whether a pollutant has an outdoor or an indoor source, most exposure to the pollutant occurs indoors. Going forward, indoor exposures can be reduced by limiting the ingress of outdoor pollutants (while providing adequate ventilation with clean air), minimizing indoor sources of pollutants, updating government policies related to indoor pollution, and addressing indoor air quality during a building's initial design. Taking the suggested steps could lead to significant reductions in morbidity and mortality, greatly reducing the societal costs associated with pollutant derived ill health.

Fetal cyclophosphamide exposure induces testicular cancer and reduced spermatogenesis and ovarian follicle numbers in mice.

PubMed

Comish, Paul B; Drumond, Ana Luiza; Kinnell, Hazel L; Anderson, Richard A; Matin, Angabin; Meistrich, Marvin L; Shetty, Gunapala

2014-01-01

Exposure to radiation during fetal development induces testicular germ cell tumors (TGCT) and reduces spermatogenesis in mice. However, whether DNA damaging chemotherapeutic agents elicit these effects in mice remains unclear. Among such agents, cyclophosphamide (CP) is currently used to treat breast cancer in pregnant women, and the effects of fetal exposure to this drug manifested in the offspring must be better understood to offer such patients suitable counseling. The present study was designed to determine whether fetal exposure to CP induces testicular cancer and/or gonadal toxicity in 129 and in 129.MOLF congenic (L1) mice. Exposure to CP on embryonic days 10.5 and 11.5 dramatically increased TGCT incidence to 28% in offspring of 129 mice (control value, 2%) and to 80% in the male offspring of L1 (control value 33%). These increases are similar to those observed in both lines of mice by radiation. In utero exposure to CP also significantly reduced testis weights at 4 weeks of age to ∼ 70% of control and induced atrophic seminiferous tubules in ∼ 30% of the testes. When the in utero CP-exposed 129 mice reached adulthood, there were significant reductions in testicular and epididymal sperm counts to 62% and 70%, respectively, of controls. In female offspring, CP caused the loss of 77% of primordial follicles and increased follicle growth activation. The results indicate that i) DNA damage is a common mechanism leading to induction of testicular cancer, ii) increased induction of testis cancer by external agents is proportional to the spontaneous incidence due to inherent genetic susceptibility, and iii) children exposed to radiation or DNA damaging chemotherapeutic agents in utero may have increased risks of developing testis cancer and having reduced spermatogenic potential or diminished reproductive lifespan.

Fetal Cyclophosphamide Exposure Induces Testicular Cancer and Reduced Spermatogenesis and Ovarian Follicle Numbers in Mice

PubMed Central

Comish, Paul B.; Drumond, Ana Luiza; Kinnell, Hazel L.; Anderson, Richard A.; Matin, Angabin; Meistrich, Marvin L.; Shetty, Gunapala

2014-01-01

Exposure to radiation during fetal development induces testicular germ cell tumors (TGCT) and reduces spermatogenesis in mice. However, whether DNA damaging chemotherapeutic agents elicit these effects in mice remains unclear. Among such agents, cyclophosphamide (CP) is currently used to treat breast cancer in pregnant women, and the effects of fetal exposure to this drug manifested in the offspring must be better understood to offer such patients suitable counseling. The present study was designed to determine whether fetal exposure to CP induces testicular cancer and/or gonadal toxicity in 129 and in 129.MOLF congenic (L1) mice. Exposure to CP on embryonic days 10.5 and 11.5 dramatically increased TGCT incidence to 28% in offspring of 129 mice (control value, 2%) and to 80% in the male offspring of L1 (control value 33%). These increases are similar to those observed in both lines of mice by radiation. In utero exposure to CP also significantly reduced testis weights at 4 weeks of age to ∼70% of control and induced atrophic seminiferous tubules in ∼30% of the testes. When the in utero CP-exposed 129 mice reached adulthood, there were significant reductions in testicular and epididymal sperm counts to 62% and 70%, respectively, of controls. In female offspring, CP caused the loss of 77% of primordial follicles and increased follicle growth activation. The results indicate that i) DNA damage is a common mechanism leading to induction of testicular cancer, ii) increased induction of testis cancer by external agents is proportional to the spontaneous incidence due to inherent genetic susceptibility, and iii) children exposed to radiation or DNA damaging chemotherapeutic agents in utero may have increased risks of developing testis cancer and having reduced spermatogenic potential or diminished reproductive lifespan. PMID:24691397

Evaluation of the Tobacco Heating System 2.2. Part 8: 5-Day randomized reduced exposure clinical study in Poland.

PubMed

Haziza, Christelle; de La Bourdonnaye, Guillaume; Skiada, Dimitra; Ancerewicz, Jacek; Baker, Gizelle; Picavet, Patrick; Lüdicke, Frank

2016-11-30

The Tobacco Heating System (THS) 2.2, a candidate Modified Risk Tobacco Product (MRTP), is designed to heat tobacco without burning it. Tobacco is heated in order to reduce the formation of harmful and potentially harmful constituents (HPHC), and reduce the consequent exposure, compared with combustible cigarettes (CC). In this 5-day exposure, controlled, parallel-group, open-label clinical study, 160 smoking, healthy subjects were randomized to three groups and asked to: (1) switch from CCs to THS 2.2 (THS group; 80 participants); (2) continue to use their own non-menthol CC brand (CC group; 41 participants); or (3) to refrain from smoking (smoking abstinence (SA) group; 39 participants). Biomarkers of exposure, except those associated with nicotine exposure, were significantly reduced in the THS group compared with the CC group, and approached the levels observed in the SA group. Increased product consumption and total puff volume were reported in the THS group. However, exposure to nicotine was similar to CC at the end of the confinement period. Reduction in urge-to-smoke was comparable between the THS and CC groups and THS 2.2 product was well tolerated. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

DNA Topoisomerase IB as a Potential Ionizing Radiation Exposure and Dose Biomarker.

PubMed

Daudee, Rotem; Gonen, Rafi; German, Uzi; Orion, Itzhak; Alfassi, Zeev B; Priel, Esther

2018-06-01

In radiation exposure scenarios where physical dosimetry is absent or inefficient, dose estimation must rely on biological markers. A reliable biomarker is of utmost importance in correlating biological system changes with radiation exposure. Human DNA topoisomerase ІB (topo І) is a ubiquitous nuclear enzyme, which is involved in essential cellular processes, including transcription, DNA replication and DNA repair, and is the target of anti-cancer drugs. It has been shown that the cellular activity of this enzyme is significantly sensitive to various DNA lesions, including radiation-induced DNA damages. Therefore, we investigated the potential of topo I as a biomarker of radiation exposure and dose. We examined the effect of exposure of different human cells to beta, X-ray and gamma radiation on the cellular catalytic activity of topo I. The results demonstrate a significant reduction in the DNA relaxation activity of topo I after irradiation and the level of the reduction was correlated with radiation dose. In normal human peripheral blood lymphocytes, exposure for 3 h to an integral dose of 0.065 mGy from tritium reduced the enzyme activity to less than 25%. In MG-63 osteoblast-like cells and in human pulmonary fibroblast (HPF) cells exposed to gamma radiation from a 60 Co source (up to 2 Gy) or to X rays (up to 2.8 Gy), a significant decrease in topo I catalytic activity was also observed. We observed that the enzyme-protein level was not altered but was partially posttranslational modified by ADP-ribosylation of the enzyme protein that is known to reduce topo I activity. The results of this study suggest that the decrease in the cellular topo I catalytic activity after low-dose exposure to different radiation types may be considered as a novel biomarker of ionizing radiation exposure and dose. For this purpose, a suitable ELISA-based method for large-scale analysis of radiation-induced topo I modification is under development.

Reducing Health Risks from Indoor Exposures in Rapidly Developing Urban China

PubMed Central

Zhang, Yinping; Mo, Jinhan

2013-01-01

Background: Over the past two decades there has been a large migration of China’s population from rural to urban regions. At the same time, residences in cities have changed in character from single-story or low-rise buildings to high-rise structures constructed and furnished with many synthetic materials. As a consequence, indoor exposures (to pollutants with outdoor and indoor sources) have changed significantly. Objectives: We briefly discuss the inferred impact that urbanization and modernization have had on indoor exposures and public health in China. We argue that growing adverse health costs associated with these changes are not inevitable, and we present steps that could be taken to reduce indoor exposures to harmful pollutants. Discussion: As documented by China’s Ministry of Health, there have been significant increases in morbidity and mortality among urban residents over the past 20 years. Evidence suggests that the population’s exposure to air pollutants has contributed to increases in lung cancer, cardiovascular disease, pulmonary disease, and birth defects. Whether a pollutant has an outdoor or an indoor source, most exposure to the pollutant occurs indoors. Going forward, indoor exposures can be reduced by limiting the ingress of outdoor pollutants (while providing adequate ventilation with clean air), minimizing indoor sources of pollutants, updating government policies related to indoor pollution, and addressing indoor air quality during a building’s initial design. Conclusions: Taking the suggested steps could lead to significant reductions in morbidity and mortality, greatly reducing the societal costs associated with pollutant derived ill health. PMID:23665813

An evaluation of retrofit engineering control interventions to reduce perchloroethylene exposures in commercial dry-cleaning shops.

PubMed

Earnest, G Scott; Ewers, Lynda M; Ruder, Avima M; Petersen, Martin R; Kovein, Ronald J

2002-02-01

Real-time monitoring was used to evaluate the ability of engineering control devices retrofitted on two existing dry-cleaning machines to reduce worker exposures to perchloroethylene. In one dry-cleaning shop, a refrigerated condenser was installed on a machine that had a water-cooled condenser to reduce the air temperature, improve vapor recovery, and lower exposures. In a second shop, a carbon adsorber was retrofitted on a machine to adsorb residual perchloroethylene not collected by the existing refrigerated condenser to improve vapor recovery and reduce exposures. Both controls were successful at reducing the perchloroethylene exposures of the dry-cleaning machine operator. Real-time monitoring was performed to evaluate how the engineering controls affected exposures during loading and unloading the dry-cleaning machine, a task generally considered to account for the highest exposures. The real-time monitoring showed that dramatic reductions occurred in exposures during loading and unloading of the dry-cleaning machine due to the engineering controls. Peak operator exposures during loading and unloading were reduced by 60 percent in the shop that had a refrigerated condenser installed on the dry-cleaning machine and 92 percent in the shop that had a carbon adsorber installed. Although loading and unloading exposures were dramatically reduced, drops in full-shift time-weighted average (TWA) exposures were less dramatic. TWA exposures to perchloroethylene, as measured by conventional air sampling, showed smaller reductions in operator exposures of 28 percent or less. Differences between exposure results from real-time and conventional air sampling very likely resulted from other uncontrolled sources of exposure, differences in shop general ventilation before and after the control was installed, relatively small sample sizes, and experimental variability inherent in field research. Although there were some difficulties and complications with installation and

Potential Exposures to Australian Bat Lyssavirus Notified in Queensland, Australia, 2009−2014

PubMed Central

Si, Damin; Marquess, John; Donnan, Ellen; Harrower, Bruce; McCall, Bradley; Bennett, Sonya; Lambert, Stephen

2016-01-01

Background Australian bat lyssavirus (ABLV) belongs to the genus Lyssavirus which also includes classic rabies virus and the European lyssaviruses. To date, the only three known human ABLV cases, all fatal, have been reported from Queensland, Australia. ABLV is widely distributed in Australian bats, and any bite or scratch from an Australian bat is considered a potential exposure to ABLV. Methodology/Principal Findings Potential exposure to ABLV has been a notifiable condition in Queensland since 2005. We analysed notification data for potential exposures occurring between 2009 and 2014. There were 1,515 potential exposures to ABLV notified in Queensland, with an average annual notification rate of 5.6 per 100,000 population per year. The majority of notified individuals (96%) were potentially exposed to ABLV via bats, with a small number of cases potentially exposed via two ABLV infected horses and an ABLV infected human. The most common routes of potential exposure were through bat scratches (47%) or bites (37%), with less common routes being mucous membrane/broken skin exposure to bat saliva/brain tissue (2.2%). Intentional handling of bats by the general public was the major cause of potential exposures (56% of notifications). Examples of these potential exposures included people attempting to rescue bats caught in barbed wire fences/fruit tree netting, or attempting to remove bats from a home. Following potential exposures, 1,399 cases (92%) were recorded as having appropriate post-exposure prophylaxis (PEP) as defined in national guidelines, with the remainder having documentation of refusal or incomplete PEP. Up to a quarter of notifications occurred after two days from the potential exposure, but with some delays being more than three weeks. Of 393 bats available for testing during the reporting period, 20 (5.1%) had ABLV detected, including four species of megabats (all flying foxes) and one species of microbats (yellow-bellied sheathtail bat). Conclusions

Coal seam gas water: potential hazards and exposure pathways in Queensland.

PubMed

Navi, Maryam; Skelly, Chris; Taulis, Mauricio; Nasiri, Shahram

2015-01-01

The extraction of coal seam gas (CSG) produces large volumes of potentially contaminated water. It has raised concerns about the environmental health impacts of the co-produced CSG water. In this paper, we review CSG water contaminants and their potential health effects in the context of exposure pathways in Queensland's CSG basins. The hazardous substances associated with CSG water in Queensland include fluoride, boron, lead and benzene. The exposure pathways for CSG water are (1) water used for municipal purposes; (2) recreational water activities in rivers; (3) occupational exposures; (4) water extracted from contaminated aquifers; and (5) indirect exposure through the food chain. We recommend mapping of exposure pathways into communities in CSG regions to determine the potentially exposed populations in Queensland. Future efforts to monitor chemicals of concern and consolidate them into a central database will build the necessary capability to undertake a much needed environmental health impact assessment.

Diagrams Showing Actions for Reducing Exposures to Polychlorinated Biphenyls (PCBs) in Indoor Building Environments

EPA Pesticide Factsheets

This diagram compliments the document, PCBs in Building Materials: Q's & A's, on how exposure to PCBs can be assessed and reduced in school buildings. It describes actions for reducing exposures to PCBs in indoor school building environments.

Assessment of self-help methods to reduce potential exposure to radiological contamination after a large-scale radiological release.

PubMed

Snyder, Emily; Drake, John; Cardarelli, John; Hall, Kathy; Szabo, Jeff; Demmer, Rick; Lindberg, Michael; Riggs, Karen; James, Ryan

2014-09-01

After the release of radioactive materials from a large radiological dispersal device (e.g., dirty bomb), improvised nuclear detonation, or nuclear power plant accident, up to hundreds of square miles may be contaminated. A portion of this area will be evacuated; however, people living in the portion that is not evacuated yet is still contaminated with low-levels of radioactive contamination will be asking for ways they can reduce their exposure. Whether cleaning activities can significantly reduce exposure is not fully understood. In this effort, the ability of cleaning activities to remove cesium (137Cs) was studied. The removal efficacy of cleaning with a commercial product, Simple Green®, was compared to cleaning with water for hard surfaces typically seen in residences. The removal efficacy of laundering fabric material surfaces was also determined for a range of conditions (e.g., fabric material type, wash temperature). During these studies, assessments of the implications of these activities (e.g., cross-contamination, resulting waste streams) were also completed. Simple Green and water were effective for removing 137Cs from plastic laminate and vinyl flooring (93.4-96.8%) but were not effective for removing 137Cs from painted wallboard and wood (7.3-68.1%). It was also determined that there was no significant difference between the two cleaners on all of the surfaces, except plastic laminate, for which Simple Green was slightly more effective. Laundering was effective for removing 137Cs contamination from polyester and cotton swatches and cotton comforters (up to 96.8% in the single swatch testing).

Reducing Children's Implicit Racial Bias Through Exposure to Positive Out-Group Exemplars.

PubMed

Gonzalez, Antonya M; Steele, Jennifer R; Baron, Andrew S

2017-01-01

Studies with adults suggest that implicit preferences favoring White versus Black individuals can be reduced through exposure to positive Black exemplars. However, it remains unclear whether developmental differences exist in the capacity for these biases to be changed. This study included 369 children and examined whether their implicit racial bias would be reduced following exposure to positive Black exemplars. Results showed that children's implicit pro-White bias was reduced following exposure to positive Black exemplars, but only for older children (M age  = ~10 years). Younger children's (M age  = ~7 years) implicit bias was not affected by this intervention. These results suggest developmental differences in the malleability of implicit racial biases and point to possible age differences in intervention effectiveness. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

Survival and Locomotory Behavior of Earwigs After Exposure to Reduced-Risk Insecticides.

PubMed

Freitas, Catarina D; Gontijo, Lessando M; Guedes, Raul Narciso C; Chediak, Mateus

2017-08-01

The conservation of natural enemies is an important tactic to promote biological control of arthropod pests. The earwig Doru luteipes (Sccuder) is the most important predator of the fall armyworm Spodoptera frugiperda (J.E. Smith) in corn fields. One way of conserving these predators in the field is by using only selective insecticides when the pest population reaches the economic threshold. Some recent insecticides such as azadirachtin, chlorantraniliprole, and novaluron have been claimed to pose reduced risk for natural enemies. Nevertheless, there is a dearth of information regarding the selectivity of these insecticides upon earwigs in specific. In this study, we carried out a series of laboratory assays to examine the survivorship and locomotory behavior of D. luteipes after exposure to fresh dry residue of azadirachtin, chlorantraniliprole, and novaluron. Our results show a significant survival reduction for D. luteipes nymphs exposed to fresh residues of chlorantraniliprole and novaluron. In the behavioral studies, adults of D. luteipes stopped more often, spent more time resting (inactive), and moved more slowly immediately after exposure to chlorantraniliprole residue. These results suggest that chlorantraniliprole may mediate an impaired movement and a behavior arrestment of earwigs after contact with this insecticide fresh residue. This could translate into reduced foraging efficiency, and increase exposure and insecticide uptake. Although chlorantraniliprole and novaluron showed a potential to undermine the biological control provided by earwigs, it is yet essential to conduct field trials in order to confirm our laboratory results. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Potentiation of glucocorticoid release does not modify the long-term effects of a single exposure to immobilization stress.

PubMed

Dal-Zotto, Silvina; Martí, Octavi; Delgado, Raúl; Armario, Antonio

2004-12-01

Previous work has shown that a single exposure of rats to a severe stressor (immobilization, IMO) results, days to weeks later, in a reduced response (desensitization) of the hypothalamic-pituitary-adrenal (HPA) axis to a second exposure to the same stressor. In the present work, we studied the influence of both length of exposure to IMO and circulating levels of corticosterone on the first day on the degree of desensitization of two sets of physiological variables: HPA hormones and food intake. Rats were given SC saline or ACTH administration and then exposed to IMO for 0, 1 or 20 min. Seven days later, all rats were exposed to 20 min IMO. HPA response was followed on both experimental days by repeated blood sampling and food intake was measured on a 24-h basis. Both ACTH administration and IMO activates the HPA axis and IMO reduced food intake for several days. A single previous experience with IMO enhanced the post-IMO return of HPA hormones to basal levels on day 8 and reduced the degree of anorexia. The protective effect of previous IMO on food intake was independent of, whereas that on HPA activation was positively related to, the length of exposure on day 1. Concomitant ACTH administration on day 1 did not modify the observed effects. Long-term protective effects of a single exposure to IMO are observed even with a brief exposure, but they are not potentiated by increasing corticosterone levels during the first exposure.

POTENTIAL EXPOSURE TO DIAZINON DURING YARD APPLICATIONS

EPA Science Inventory

Applicators applying diazinon to yards were monitored to determine potential exposures received while using this commonly available pesticide around the home. Diazinon was applied to lawns and shrubs using compressed air or hose-end sprayers. Even with minimal clothing, the large...

The social consequences of conspiracism: Exposure to conspiracy theories decreases intentions to engage in politics and to reduce one's carbon footprint.

PubMed

Jolley, Daniel; Douglas, Karen M

2014-02-01

The current studies explored the social consequences of exposure to conspiracy theories. In Study 1, participants were exposed to a range of conspiracy theories concerning government involvement in significant events such as the death of Diana, Princess of Wales. Results revealed that exposure to information supporting conspiracy theories reduced participants' intentions to engage in politics, relative to participants who were given information refuting conspiracy theories. This effect was mediated by feelings of political powerlessness. In Study 2, participants were exposed to conspiracy theories concerning the issue of climate change. Results revealed that exposure to information supporting the conspiracy theories reduced participants' intentions to reduce their carbon footprint, relative to participants who were given refuting information, or those in a control condition. This effect was mediated by powerlessness with respect to climate change, uncertainty, and disillusionment. Exposure to climate change conspiracy theories also influenced political intentions, an effect mediated by political powerlessness. The current findings suggest that conspiracy theories may have potentially significant social consequences, and highlight the need for further research on the social psychology of conspiracism. © 2012 The British Psychological Society.

Climate change: the potential impact on occupational exposure to pesticides.

PubMed

Gatto, Maria Pia; Cabella, Renato; Gherardi, Monica

2016-01-01

This study investigates the possible influence of global climate change (GCC) on exposure to plant protection products (PPP) in the workplace. The paper has evaluated the main potential relationships between GCC and occupational exposure to pesticides, by highlighting how global warming might affect their future use and by reviewing its possible consequence on workers' exposure. Global warming, influencing the spatial and temporal distribution and proliferation of weeds, the impact of already present insect pests and pathogens and the introduction of new infesting species, could cause a changed use of pesticides in terms of higher amounts, doses and types of products applied, so influencing the human exposure to them during agricultural activities. GCC, in particular heat waves, may also potentially have impact on workers' susceptibility to pesticides absorption. Prevention policies of health in the workplace must be ready to address new risks from occupational exposure to pesticide, presumably different from current risks, since an increased use may be expected.

Can Spirulina maxima reduce the mutagenic potential of sibutramine?

PubMed

Araldi, R P; Santos, N P; Mendes, T B; Carvalho, L B; Ito, E T; de-Sá-Júnior, P L; Souza, E B

2015-12-28

The worldwide obesity pandemic requires the use of anti-obesity drugs. Sibutramine is an anti-obesity drug that has been used worldwide but is indiscriminately consumed in Brazil. Several studies have demonstrated that sibutramine promotes weight loss and weight maintenance, but several side effects have been associated with its systematic consumption. For this reason, sibutramine was withdrawn from the European and American markets, but still remains legal for use in Brazil. Studies have shown that a 5-10% reduction in body weight results in outstanding health benefits for obese patients. However, in order to promote significant weight loss, it is necessary to use sibutramine for at least 2 years. This long-term exposure has carcinogenic potential, as sibutramine causes DNA damage. Thus, this study evaluated the in vivo mutagenic potential of sibutramine alone (5, 7, 10, 15, and 20 mg/kg) and in association with Spirulina maxima (150 and 300 mg/kg), a cyanobacterium with antioxidant potential, using the polychromatic erythrocyte micronucleus test. Our results reinforced the mutagenic potential of sibutramine alone, which showed a time-dependent action. Combinatory treatments with S. maxima were not able to reduce the genotoxicity of sibutramine. These results were confirmed in vitro with the cytokinesis-blocked micronucleus test. In conclusion, our data showed that new alternative anti-obesity treatments are needed since the consumption of sibutramine can increase the risk of cancer in overweight patients.

Microhabitats reduce animal's exposure to climate extremes.

PubMed

Scheffers, Brett R; Edwards, David P; Diesmos, Arvin; Williams, Stephen E; Evans, Theodore A

2014-02-01

Extreme weather events, such as unusually hot or dry conditions, can cause death by exceeding physiological limits, and so cause loss of population. Survival will depend on whether or not susceptible organisms can find refuges that buffer extreme conditions. Microhabitats offer different microclimates to those found within the wider ecosystem, but do these microhabitats effectively buffer extreme climate events relative to the physiological requirements of the animals that frequent them? We collected temperature data from four common microhabitats (soil, tree holes, epiphytes, and vegetation) located from the ground to canopy in primary rainforests in the Philippines. Ambient temperatures were monitored from outside of each microhabitat and from the upper forest canopy, which represent our macrohabitat controls. We measured the critical thermal maxima (CTmax ) of frog and lizard species, which are thermally sensitive and inhabit our microhabitats. Microhabitats reduced mean temperature by 1-2 °C and reduced the duration of extreme temperature exposure by 14-31 times. Microhabitat temperatures were below the CTmax of inhabitant frogs and lizards, whereas macrohabitats consistently contained lethal temperatures. Microhabitat temperatures increased by 0.11-0.66 °C for every 1 °C increase in macrohabitat temperature, and this nonuniformity in temperature change influenced our forecasts of vulnerability for animal communities under climate change. Assuming uniform increases of 6 °C, microhabitats decreased the vulnerability of communities by up to 32-fold, whereas under nonuniform increases of 0.66 to 3.96 °C, microhabitats decreased the vulnerability of communities by up to 108-fold. Microhabitats have extraordinary potential to buffer climate and likely reduce mortality during extreme climate events. These results suggest that predicted changes in distribution due to mortality and habitat shifts that are derived from macroclimatic samples and that assume

DEVELOPMENT OF A DIETARY EXPOSURE POTENTIAL MODEL FOR EVALUATING DIETARY EXPOSURE TO CHEMICAL RESIDUES IN FOOD

EPA Science Inventory

The Dietary Exposure Potential Model (DEPM) is a computer-based model developed for estimating dietary exposure to chemical residues in food. The DEPM is based on food consumption data from the 1987-1988 Nationwide Food Consumption Survey (NFCS) administered by the United States ...

Assessing potential exposure of birds to pesticide-treated seeds.

PubMed

Prosser, Phil; Hart, A D M

2005-10-01

Seed treatments are widely used for crop protection and present a particular risk to granivorous birds. UK risk assessment for seed treatments has tended to focus on highly granivorous species; however, under some conditions, non-granivorous birds will take seeds. Better data is needed on which species eat seeds for which pesticide treatments are used. To identify which species will take and eat a range of crop seeds in common usage in the UK, birds visiting bait stations at which untreated seed was presented were video recorded. Information was also obtained on how much seed is taken by individual birds. The seeds tested were wheat, barley, maize, oilseed rape, grass, peas and pelleted sugar beet. For many of the species observed at the bait stations, the amounts of seed consumed during single visits were sufficient to pose a potential risk (toxicity-exposure ratio < 10) if the seed had been treated with one of the more acutely toxic seed treatments. Previous studies have shown that de-husking of seeds can substantially reduce birds' exposure. This paper provides information on which of the species recorded de-husked which seeds, in field conditions. The use of these data in pesticide risk assessment is considered.

Chronic warm exposure impairs growth performance and reduces thermal safety margins in the common triplefin fish (Forsterygion lapillum).

PubMed

McArley, Tristan J; Hickey, Anthony J R; Herbert, Neill A

2017-10-01

Intertidal fish species face gradual chronic changes in temperature and greater extremes of acute thermal exposure through climate-induced warming. As sea temperatures rise, it has been proposed that whole-animal performance will be impaired through oxygen and capacity limited thermal tolerance [OCLTT; reduced aerobic metabolic scope (MS)] and, on acute exposure to high temperatures, thermal safety margins may be reduced because of constrained acclimation capacity of upper thermal limits. Using the New Zealand triplefin fish ( Forsterygion lapillum ), this study addressed how performance in terms of growth and metabolism (MS) and upper thermal tolerance limits would be affected by chronic exposure to elevated temperature. Growth was measured in fish acclimated (12 weeks) to present and predicted future temperatures and metabolic rates were then determined in fish at acclimation temperatures and with acute thermal ramping. In agreement with the OCLTT hypothesis, chronic exposure to elevated temperature significantly reduced growth performance and MS. However, despite the prospect of impaired growth performance under warmer future summertime conditions, an annual growth model revealed that elevated temperatures may only shift the timing of high growth potential and not the overall annual growth rate. While the upper thermal tolerance (i.e. critical thermal maxima) increased with exposure to warmer temperatures and was associated with depressed metabolic rates during acute thermal ramping, upper thermal tolerance did not differ between present and predicted future summertime temperatures. This suggests that warming may progressively decrease thermal safety margins for hardy generalist species and could limit the available habitat range of intertidal populations. © 2017. Published by The Company of Biologists Ltd.

CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS.

EPA Science Inventory

CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS. ME Gilbert1, ME Kelly2, S. Salant3, T Shafer1, J Goodman3 1Neurotoxicology Div, US EPA, RTP, NC, 27711, 2Children's Hospital, Philadelphia, PA, 19104, 3Helen Hayes Hospital, Haverstraw, NY, 10993.
...

Potential exposure to human prescription pharmaceutical residues from wastewater

EPA Science Inventory

Pharmaceuticals in the environment (PiE) pose a complicated problem, involving multiple dissimilar compounds, multiple routes of potential exposure, and a range of potentially affected organisms that span the tree of life. Key uncertainties include not knowing which of the thous...

Family and carer smoking control programmes for reducing children's exposure to environmental tobacco smoke.

PubMed

Baxi, Ruchi; Sharma, Mohit; Roseby, Robert; Polnay, Adam; Priest, Naomi; Waters, Elizabeth; Spencer, Nick; Webster, Premila

2014-03-01

Children's exposure to other people's cigarette smoke (environmental tobacco smoke, or ETS) is associated with a range of adverse health outcomes for children. Parental smoking is a common source of children's exposure to ETS. Older children are also at risk of exposure to ETS in child care or educational settings. Preventing exposure to cigarette smoke in infancy and childhood has significant potential to improve children's health worldwide. To determine the effectiveness of interventions aiming to reduce exposure of children to ETS. We searched the Cochrane Tobacco Addiction Group Specialized Register and conducted additional searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PsycINFO, EMBASE, CINAHL, ERIC, and The Social Science Citation Index & Science Citation Index (Web of Knowledge). Date of the most recent search: September 2013. Controlled trials with or without random allocation. Interventions must have addressed participants (parents and other family members, child care workers and teachers) involved with the care and education of infants and young children (aged 0 to 12 years). All mechanisms for reduction of children's ETS exposure, and smoking prevention, cessation, and control programmes were included. These include health promotion, social-behavioural therapies, technology, education, and clinical interventions. Two authors independently assessed studies and extracted data. Due to heterogeneity of methodologies and outcome measures, no summary measures were possible and results were synthesised narratively. Fifty-seven studies met the inclusion criteria. Seven studies were judged to be at low risk of bias, 27 studies were judged to have unclear overall risk of bias and 23 studies were judged to have high risk of bias. Seven interventions were targeted at populations or community settings, 23 studies were conducted in the 'well child' healthcare setting and 24 in the 'ill child' healthcare setting. Two further studies

Comparison of Modeling Approaches to Prioritize Chemicals Based on Estimates of Exposure and Exposure Potential

EPA Science Inventory

While only limited data are available to characterize the potential toxicity of over 8 million commercially available chemical substances, there is even less information available on the exposure and use-scenarios that are required to link potential toxicity to human and ecologic...

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.

Prevention-intervention strategies to reduce exposure to e-waste.

PubMed

Heacock, Michelle; Trottier, Brittany; Adhikary, Sharad; Asante, Kwadwo Ansong; Basu, Nil; Brune, Marie-Noel; Caravanos, Jack; Carpenter, David; Cazabon, Danielle; Chakraborty, Paromita; Chen, Aimin; Barriga, Fernando Diaz; Ericson, Bret; Fobil, Julius; Haryanto, Budi; Huo, Xia; Joshi, T K; Landrigan, Philip; Lopez, Adeline; Magalini, Frederico; Navasumrit, Panida; Pascale, Antonio; Sambandam, Sankar; Aslia Kamil, Upik Sitti; Sly, Leith; Sly, Peter; Suk, Ann; Suraweera, Inoka; Tamin, Ridwan; Vicario, Elena; Suk, William

2018-06-27

As one of the largest waste streams, electronic waste (e-waste) production continues to grow in response to global demand for consumer electronics. This waste is often shipped to developing countries where it is disassembled and recycled. In many cases, e-waste recycling activities are conducted in informal settings with very few controls or protections in place for workers. These activities involve exposure to hazardous substances such as cadmium, lead, and brominated flame retardants and are frequently performed by women and children. Although recycling practices and exposures vary by scale and geographic region, we present case studies of e-waste recycling scenarios and intervention approaches to reduce or prevent exposures to the hazardous substances in e-waste that may be broadly applicable to diverse situations. Drawing on parallels identified in these cases, we discuss the future prevention and intervention strategies that recognize the difficult economic realities of informal e-waste recycling.

75 FR 8375 - Device Improvements to Reduce Unnecessary Radiation Exposure From Medical Imaging; Public Meeting...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-24

... radiologic technologists or technologists in other specialties as well as physicians in all medical...] Device Improvements to Reduce Unnecessary Radiation Exposure From Medical Imaging; Public Meeting... Improvements to Reduce Unnecessary Radiation Exposure From Medical Imaging.'' The purpose of this meeting is to...

Beneficial cardiovascular effects of reducing exposure to particulate air pollution with a simple facemask.

PubMed

Langrish, Jeremy P; Mills, Nicholas L; Chan, Julian Kk; Leseman, Daan Lac; Aitken, Robert J; Fokkens, Paul Hb; Cassee, Flemming R; Li, Jing; Donaldson, Ken; Newby, David E; Jiang, Lixin

2009-03-13

Exposure to air pollution is an important risk factor for cardiovascular morbidity and mortality, and is associated with increased blood pressure, reduced heart rate variability, endothelial dysfunction and myocardial ischaemia. Our objectives were to assess the cardiovascular effects of reducing air pollution exposure by wearing a facemask. In an open-label cross-over randomised controlled trial, 15 healthy volunteers (median age 28 years) walked on a predefined city centre route in Beijing in the presence and absence of a highly efficient facemask. Personal exposure to ambient air pollution and exercise was assessed continuously using portable real-time monitors and global positional system tracking respectively. Cardiovascular effects were assessed by continuous 12-lead electrocardiographic and ambulatory blood pressure monitoring. Ambient exposure (PM2.5 86 +/- 61 vs 140 +/- 113 mug/m3; particle number 2.4 +/- 0.4 vs 2.3 +/- 0.4 x 104 particles/cm3), temperature (29 +/- 1 vs 28 +/- 3 degrees C) and relative humidity (63 +/- 10 vs 64 +/- 19%) were similar (P > 0.05 for all) on both study days. During the 2-hour city walk, systolic blood pressure was lower (114 +/- 10 vs 121 +/- 11 mmHg, P < 0.01) when subjects wore a facemask, although heart rate was similar (91 +/- 11 vs 88 +/- 11/min; P > 0.05). Over the 24-hour period heart rate variability increased (SDNN 65.6 +/- 11.5 vs 61.2 +/- 11.4 ms, P < 0.05; LF-power 919 +/- 352 vs 816 +/- 340 ms2, P < 0.05) when subjects wore the facemask. Wearing a facemask appears to abrogate the adverse effects of air pollution on blood pressure and heart rate variability. This simple intervention has the potential to protect susceptible individuals and prevent cardiovascular events in cities with high concentrations of ambient air pollution.

Does drywall installers' innovative idea reduce the ergonomic exposures of ceiling installation: A field case study.

PubMed

Dasgupta, Priyadarshini Sengupta; Punnett, Laura; Moir, Susan; Kuhn, Sarah; Buchholz, Bryan

2016-07-01

The study was conducted to assess an intervention suggested by the workers to reduce the physical or ergonomic exposures of the drywall installation task. The drywall installers were asked to brainstorm on innovative ideas that could reduce their ergonomic exposures during the drywall installation work. The workers proposed the idea of using a 'deadman' (narrow panel piece) to hold the panels to the ceiling while installing them. The researcher collected quantitative exposure data (PATH, 3DSSPP) at the baseline and intervention phases and compared the phases to find out any change in the exposure while using the 'deadman'. Results showed that ergonomic exposures (such as overhead arm and awkward trunk postures and heavy load handling) were reduced at the intervention phase while using the 'deadman' with an electrically operated lift. The concept of the 'deadman', which was shown to help reduce musculoskeletal exposures during ceiling installation, can be used to fabricate a permanent ergonomic tool to support the ceiling drywall panel. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Maternal peanut exposure during pregnancy and lactation reduces peanut allergy risk in offspring.

PubMed

López-Expósito, Iván; Song, Ying; Järvinen, Kirsi M; Srivastava, Kamal; Li, Xiu-Min

2009-11-01

Maternal allergy is believed to be a risk factor for peanut allergy (PNA) in children. However, there is no direct evidence of maternal transmission of PNA susceptibility, and it is unknown whether maternal peanut exposure affects the development of PNA in offspring. To investigate the influence of maternal PNA on offspring reactions to the first peanut exposure, and whether maternal low-dose peanut exposure during pregnancy and lactation influences these reactions and peanut sensitization in a murine model. Five-week-old offspring of PNA C3H/HeJ mothers (PNA-Ms) were challenged intragastrically with peanut (first exposure), and reactions were determined. In a subset of the experiment, PNA-Ms were fed a low dose of peanut (PNA-M/PN) or not fed peanut (PNA-M/none) during pregnancy and lactation. Their 5-week-old offspring were challenged intragastrically with peanut, and reactions were determined. In another subset of the experiment, offspring of PNA-M/PN or PNA-M/none were sensitized with peanut intragastrically for 6 weeks, and serum peanut-specific antibodies were determined. PNA-M offspring exhibited anaphylactic reactions at first exposure to peanut that were associated with peanut-specific IgG(1) levels and prevented by a platelet activation factor antagonist. In a subset experiment, PNA-M/PN offspring showed significantly reduced first-exposure peanut reactions, increased IgG(2a), and reduced mitogen-stimulated splenocyte cytokine production compared with PNA-M/none offspring. In an additional experiment, PNA-M/PN offspring showed reduction of peanut-specific IgE to active peanut sensitization. We show for the first time maternal transmission of susceptibility to first-exposure peanut reactions and active peanut sensitization. Low-dose peanut exposure during pregnancy and lactation reduced this risk.

Reducing Blood-borne Exposure in Interventional Radiology: What the IR Should Know

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

Tso, David K.; Athreya, Sriharsha, E-mail: sathreya@stjoes.ca

2013-08-01

Interventional radiologists are at risk of exposure to blood-borne pathogens in their day-to-day practice. Percutaneous exposure from unsafe sharps handling, mucocutaneous exposure from body fluid splashes, and glove perforation from excessive wear can expose the radiologist to potentially infectious material. The increasing prevalence of blood-borne pathogens, including hepatitis B and C, and human immunodeficiency virus, puts nurses, residents, fellows, and interventional radiologists at risk for occupational exposure. This review outlines suggestions to establish a culture of safety in the interventional suite.

Synthetic materials to reduce exposure to mycotoxins in fermented foods and beverages

USDA-ARS?s Scientific Manuscript database

Mycotoxins are a broad class of toxic fungal metabolites that occasionally contaminate agricultural commodities. Mycotoxin contamination reduces the value of affected commodities and negatively impacts the health of consumers. A popular approach to reduce the effects of exposure to mycotoxins is the...

Global approach to reducing lead exposure and poisoning.

PubMed

Meyer, Pamela A; Brown, Mary Jean; Falk, Henry

2008-01-01

Lead poisoning is an important environmental disease that can have life-long adverse health effects. Most susceptible are children, and most commonly exposed are those who are poor and live in developing countries. Studies of children's blood-lead levels (BLLs) are showing cognitive impairment at increasingly lower BLLs. Lead is dangerous at all levels in children. The sources of lead exposure vary among and within countries depending on past and current uses. Sources of lead may be from historic contamination, recycling old lead products, or from manufacturing new products. In all countries that have banned leaded gasoline, average population BLLs have declined rapidly. In many developing countries where leaded gasoline is no longer used, many children and workers are exposed to fugitive emissions and mining wastes. Unexpected lead threats, such as improper disposal of electronics and children's toys contaminated with lead, continue to emerge. The only medical treatment available is chelation, which can save lives of persons with very high BLLs. However, chelating drugs are not always available in developing countries and have limited value in reducing the sequelae of chronic low dose lead exposure. Therefore, the best approach is to prevent exposure to lead. Because a key strategy for preventing lead poisoning is to identify and control or eliminate lead sources, this article highlights several major sources of lead poisoning worldwide. In addition, we recommend three primary prevention strategies for lead poisoning: identify sources, eliminate or control sources, and monitor environmental exposures and hazards.

Professional and Home-Made Face Masks Reduce Exposure to Respiratory Infections among the General Population

PubMed Central

van der Sande, Marianne; Teunis, Peter; Sabel, Rob

2008-01-01

Background Governments are preparing for a potential influenza pandemic. Therefore they need data to assess the possible impact of interventions. Face-masks worn by the general population could be an accessible and affordable intervention, if effective when worn under routine circumstances. Methodology We assessed transmission reduction potential provided by personal respirators, surgical masks and home-made masks when worn during a variety of activities by healthy volunteers and a simulated patient. Principal Findings All types of masks reduced aerosol exposure, relatively stable over time, unaffected by duration of wear or type of activity, but with a high degree of individual variation. Personal respirators were more efficient than surgical masks, which were more efficient than home-made masks. Regardless of mask type, children were less well protected. Outward protection (mask wearing by a mechanical head) was less effective than inward protection (mask wearing by healthy volunteers). Conclusions/Significance Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection. Masks worn by patients may not offer as great a degree of protection against aerosol transmission. PMID:18612429

Professional and home-made face masks reduce exposure to respiratory infections among the general population.

PubMed

van der Sande, Marianne; Teunis, Peter; Sabel, Rob

2008-07-09

Governments are preparing for a potential influenza pandemic. Therefore they need data to assess the possible impact of interventions. Face-masks worn by the general population could be an accessible and affordable intervention, if effective when worn under routine circumstances. We assessed transmission reduction potential provided by personal respirators, surgical masks and home-made masks when worn during a variety of activities by healthy volunteers and a simulated patient. All types of masks reduced aerosol exposure, relatively stable over time, unaffected by duration of wear or type of activity, but with a high degree of individual variation. Personal respirators were more efficient than surgical masks, which were more efficient than home-made masks. Regardless of mask type, children were less well protected. Outward protection (mask wearing by a mechanical head) was less effective than inward protection (mask wearing by healthy volunteers). Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection. Masks worn by patients may not offer as great a degree of protection against aerosol transmission.

Cigarette smoke induced genotoxicity and respiratory tract pathology: evidence to support reduced exposure time and animal numbers in tobacco product testing

PubMed Central

Dalrymple, Annette; Ordoñez, Patricia; Thorne, David; Walker, David; Camacho, Oscar M.; Büttner, Ansgar; Dillon, Debbie; Meredith, Clive

2016-01-01

Abstract Many laboratories are working to develop in vitro models that will replace in vivo tests, but occasionally there remains a regulatory expectation of some in vivo testing. Historically, cigarettes have been tested in vivo for 90 days. Recently, methods to reduce and refine animal use have been explored. This study investigated the potential of reducing animal cigarette smoke (CS) exposure to 3 or 6 weeks, and the feasibility of separate lung lobes for histopathology or the Comet assay. Rats were exposed to sham air or CS (1 or 2 h) for 3 or 6 weeks. Respiratory tissues were processed for histopathological evaluation, and Alveolar type II cells (AEC II) isolated for the Comet assay. Blood was collected for Pig-a and micronucleus quantification. Histopathological analyses demonstrated exposure effects, which were generally dependent on CS dose (1 or 2 h, 5 days/week). Comet analysis identified that DNA damage increased in AEC II following 3 or 6 weeks CS exposure, and the level at 6 weeks was higher than 3 weeks. Pig-a mutation or micronucleus levels were not increased. In conclusion, this study showed that 3 weeks of CS exposure was sufficient to observe respiratory tract pathology and DNA damage in isolated AEC II. Differences between the 3 and 6 week data imply that DNA damage in the lung is cumulative. Reducing exposure time, plus analyzing separate lung lobes for DNA damage or histopathology, supports a strategy to reduce and refine animal use in tobacco product testing and is aligned to the 3Rs (replacement, reduction and refinement). PMID:27160659

Cigarette smoke induced genotoxicity and respiratory tract pathology: evidence to support reduced exposure time and animal numbers in tobacco product testing.

PubMed

Dalrymple, Annette; Ordoñez, Patricia; Thorne, David; Walker, David; Camacho, Oscar M; Büttner, Ansgar; Dillon, Debbie; Meredith, Clive

2016-06-01

Many laboratories are working to develop in vitro models that will replace in vivo tests, but occasionally there remains a regulatory expectation of some in vivo testing. Historically, cigarettes have been tested in vivo for 90 days. Recently, methods to reduce and refine animal use have been explored. This study investigated the potential of reducing animal cigarette smoke (CS) exposure to 3 or 6 weeks, and the feasibility of separate lung lobes for histopathology or the Comet assay. Rats were exposed to sham air or CS (1 or 2 h) for 3 or 6 weeks. Respiratory tissues were processed for histopathological evaluation, and Alveolar type II cells (AEC II) isolated for the Comet assay. Blood was collected for Pig-a and micronucleus quantification. Histopathological analyses demonstrated exposure effects, which were generally dependent on CS dose (1 or 2 h, 5 days/week). Comet analysis identified that DNA damage increased in AEC II following 3 or 6 weeks CS exposure, and the level at 6 weeks was higher than 3 weeks. Pig-a mutation or micronucleus levels were not increased. In conclusion, this study showed that 3 weeks of CS exposure was sufficient to observe respiratory tract pathology and DNA damage in isolated AEC II. Differences between the 3 and 6 week data imply that DNA damage in the lung is cumulative. Reducing exposure time, plus analyzing separate lung lobes for DNA damage or histopathology, supports a strategy to reduce and refine animal use in tobacco product testing and is aligned to the 3Rs (replacement, reduction and refinement).

Reducing tobacco smoking and smoke exposure to prevent preterm birth and its complications.

PubMed

Wagijo, Mary-Ann; Sheikh, Aziz; Duijts, Liesbeth; Been, Jasper V

2017-03-01

Tobacco smoking and smoke exposure during pregnancy are associated with a range of adverse health outcomes, including preterm birth. Also, children born preterm have a higher risk of complications including bronchopulmonary dysplasia and asthma when their mothers smoked during pregnancy. Smoking cessation in early pregnancy can help reduce the adverse impact on offspring health. Counselling interventions are effective in promoting smoking cessation and reducing the incidence of preterm birth. Peer support and incentive-based approaches are likely to be of additional benefit, whereas the effectiveness of pharmacological interventions, including nicotine replacement therapy, has not definitely been established. Smoke-free legislation can help reduce smoke exposure as well as maternal smoking rates at a population level, and is associated with a reduction in preterm birth. Helping future mothers to stop smoking and protect their children from second hand smoke exposure must be a key priority for health care workers and policy makers alike. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nursing research in community-based approaches to reduce exposure to secondhand smoke.

PubMed

Hahn, Ellen J; Ashford, Kristin B; Okoli, Chizimuzo T C; Rayens, Mary Kay; Ridner, S Lee; York, Nancy L

2009-01-01

Secondhand smoke (SHS) is the third leading cause of preventable death in the United States and a major source of indoor air pollution, accounting for an estimated 53,000 deaths per year among nonsmokers. Secondhand smoke exposure varies by gender, race/ethnicity, and socioeconomic status. The most effective public health intervention to reduce SHS exposure is to implement and enforce smoke-free workplace policies that protect entire populations including all workers regardless of occupation, race/ethnicity, gender, age, and socioeconomic status. This chapter summarizes community and population-based nursing research to reduce SHS exposure. Most of the nursing research in this area has been policy outcome studies, documenting improvement in indoor air quality, worker's health, public opinion, and reduction in Emergency Department visits for asthma, acute myocardial infarction among women, and adult smoking prevalence. These findings suggest a differential health effect by strength of law. Further, smoke-free laws do not harm business or employee turnover, nor are revenues from charitable gaming affected. Additionally, smoke-free laws may eventually have a positive effect on cessation among adults. There is emerging nursing science exploring the link between SHS exposure to nicotine and tobacco dependence, suggesting one reason that SHS reduction is a quit smoking strategy. Other nursing research studies address community readiness for smoke-free policy, and examine factors that build capacity for smoke-free policy. Emerging trends in the field include tobacco free health care and college campuses. A growing body of nursing research provides an excellent opportunity to conduct and participate in community and population-based research to reduce SHS exposure for both vulnerable populations and society at large.

Effect of copper chloride exposure on the membrane potential and cytosolic free calcium in primary cultured chicken hepatocytes.

PubMed

Jia, Xuexia; Chen, Long; Li, Jingtao; Su, Rongsheng; Shi, Dayou; Tang, Zhaoxin

2012-09-01

This study was conducted to examine the effects of copper on membrane potential and cytosolic free calcium in isolated primary chicken hepatocytes which were exposed to different concentration of Cu(2+) (0, 10, 50, 100 μM) or a mixture of Cu(2+) and vitamin C (50 and 50 μM, respectively). Viability, membrane potential, and cytosolic free Ca(2+) of monolayer cultured hepatocytes were investigated at the indicated time point. Results showed that, among the different concentrations of Cu(2+) exposure, the viability of hepatocytes treated with 100 μM Cu(2+) was the worst at the 12th and 24th hours. The effects of Cu(2+) on viability and proliferation were time and dose dependent. Further investigation indicated that Cu(2+) exposure significantly enhanced cytosolic free Ca(2+) in hepatocytes, compared to that in control group, at the 24th hour. Meanwhile, membrane potential was noticeably reduced in hepatocytes increasing concentration of Cu(2+). Taking these results together, we have shown that Cu(2+) can cause toxicity to primary chicken hepatocytes in excessive dose and the effect of Cu(2+) exposure on membrane potential is not site specific, which is probably mediated by the changes of cytosolic free Ca(2+).

Family and carer smoking control programmes for reducing children's exposure to environmental tobacco smoke.

PubMed

Behbod, Behrooz; Sharma, Mohit; Baxi, Ruchi; Roseby, Robert; Webster, Premila

2018-01-31

Children's exposure to other people's tobacco smoke (environmental tobacco smoke, or ETS) is associated with a range of adverse health outcomes for children. Parental smoking is a common source of children's exposure to ETS. Older children in child care or educational settings are also at risk of exposure to ETS. Preventing exposure to ETS during infancy and childhood has significant potential to improve children's health worldwide. To determine the effectiveness of interventions designed to reduce exposure of children to environmental tobacco smoke, or ETS. We searched the Cochrane Tobacco Addiction Group Specialised Register and conducted additional searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PsycINFO, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Education Resource Information Center (ERIC), and the Social Science Citation Index & Science Citation Index (Web of Knowledge). We conducted the most recent search in February 2017. We included controlled trials, with or without random allocation, that enrolled participants (parents and other family members, child care workers, and teachers) involved in the care and education of infants and young children (from birth to 12 years of age). All mechanisms for reducing children's ETS exposure were eligible, including smoking prevention, cessation, and control programmes. These include health promotion, social-behavioural therapies, technology, education, and clinical interventions. Two review authors independently assessed studies and extracted data. Due to heterogeneity of methods and outcome measures, we did not pool results but instead synthesised study findings narratively. Seventy-eight studies met the inclusion criteria, and we assessed all evidence to be of low or very low quality based on GRADE assessment. We judged nine studies to be at low risk of bias, 35 to have unclear overall risk of bias, and 34 to have high risk of bias. Twenty

Exposure reduces negative bias in self-rated performance in public speaking fearful participants.

PubMed

Cheng, Joyce; Niles, Andrea N; Craske, Michelle G

2017-03-01

Individuals with public speaking anxiety (PSA) under-rate their performance compared to objective observers. The present study examined whether exposure reduces the discrepancy between self and observer performance ratings and improved observer-rated performance in individuals with PSA. PSA participants gave a speech in front of a small audience and rated their performance using a questionnaire before and after completing repeated exposures to public speaking. Non-anxious control participants gave a speech and completed the questionnaire one time only. Objective observers watched videos of the speeches and rated performance using the same questionnaire. PSA participants underrated their performance to a greater degree than did controls prior to exposure, but also performed significantly more poorly than did controls when rated objectively. Bias significantly decreased and objective-rated performance significantly increased following completion of exposure in PSA participants, and on one performance measure, anxious participants no longer showed a greater discrepancy between self and observer performance ratings compared to controls. The study employed non-clinical student sample, but the results should be replicated in clinical anxiety samples. These findings indicate that exposure alone significantly reduces negative performance bias among PSA individuals, but additional exposure or additional interventions may be necessary to fully correct bias and performance deficits. Copyright © 2016 Elsevier Ltd. All rights reserved.

Digital methods for reducing radiation exposure during medical fluoroscopy

NASA Astrophysics Data System (ADS)

Edmonds, Ernest W.; Rowlands, John A.; Hynes, David M.; Toth, B. D.; Porter, Anthony J.

1990-07-01

There is increased concern over radiation exposure to the general population from many sources. One of the most significant sources is that received by the patient during medical diagnostic procedures, and of these, the procedure with the greatest potential hazard is fluoroscopy. The legal limit for fluoroscopy in most jurisdictions is SR per minute skin exposure rate. Fluoroscopes are often operated in excess of this figure, and in the case of interventional procedures, fluorocopy times may exceed 20 minutes. With improvements in medical technology these procedures are being performed more often, and also are being carried out on younger age groups. Radiation exposure during fluoroscopy, both to patient and operator, is therefore becoming a matter of increasing concern to regulating authorities, and it is incumbent on us to develop digital technology to minimise the radiation hazard in these procedures. This paper explores the technical options available for radiation exposure reduction, including pulsed fluoroscopy, digital noise reduction, or simple reduction in exposure rate to the x-ray image intensifier. We also discuss educational aspects of fluoroscopy which radiologists should be aware of which can be more important than the technological solutions. A "work in progress" report gives a completely new approach to the implementation of a large number of possible digital algorithms, for the investigation of clinical efficacy.

Personalized technologist dose audit feedback for reducing patient radiation exposure from CT.

PubMed

Miglioretti, Diana L; Zhang, Yue; Johnson, Eric; Lee, Choonsik; Morin, Richard L; Vanneman, Nicholas; Smith-Bindman, Rebecca

2014-03-01

The aim of this study was to determine whether providing radiologic technologists with audit feedback on doses from CT examinations they conduct and education on dose-reduction strategies reduces patients' radiation exposure. This prospective, controlled pilot study was conducted within an integrated health care system from November 2010 to October 2011. Ten technologists at 2 facilities received personalized dose audit reports and education on dose-reduction strategies; 9 technologists at a control facility received no intervention. Radiation exposure was measured by the dose-length product (DLP) from CT scans performed before (n = 1,630) and after (n = 1,499) the intervention and compared using quantile regression. Technologists were surveyed before and after the intervention. For abdominal CT, DLPs decreased by 3% to 12% at intervention facilities but not at the control facility. For brain CT, DLPs significantly decreased by 7% to 12% at one intervention facility; did not change at the second intervention facility, which had the lowest preintervention DLPs; and increased at the control facility. Technologists were more likely to report always thinking about radiation exposure and associated cancer risk and optimizing settings to reduce exposure after the intervention. Personalized audit feedback and education can change technologists' attitudes about, and awareness of, radiation and can lower patient radiation exposure from CT imaging. Copyright © 2014 American College of Radiology. All rights reserved.

Potential Occupational Exposures and Health Risks Associated with Biomass-Based Power Generation.

PubMed

Rohr, Annette C; Campleman, Sharan L; Long, Christopher M; Peterson, Michael K; Weatherstone, Susan; Quick, Will; Lewis, Ari

2015-07-22

Biomass is increasingly being used for power generation; however, assessment of potential occupational health and safety (OH&S) concerns related to usage of biomass fuels in combustion-based generation remains limited. We reviewed the available literature on known and potential OH&S issues associated with biomass-based fuel usage for electricity generation at the utility scale. We considered three potential exposure scenarios--pre-combustion exposure to material associated with the fuel, exposure to combustion products, and post-combustion exposure to ash and residues. Testing of dust, fungal and bacterial levels at two power stations was also undertaken. Results indicated that dust concentrations within biomass plants can be extremely variable, with peak levels in some areas exceeding occupational exposure limits for wood dust and general inhalable dust. Fungal spore types, identified as common environmental species, were higher than in outdoor air. Our review suggests that pre-combustion risks, including bioaerosols and biogenic organics, should be considered further. Combustion and post-combustion risks appear similar to current fossil-based combustion. In light of limited available information, additional studies at power plants utilizing a variety of technologies and biomass fuels are recommended.

Potential Occupational Exposures and Health Risks Associated with Biomass-Based Power Generation

PubMed Central

Rohr, Annette C.; Campleman, Sharan L.; Long, Christopher M.; Peterson, Michael K.; Weatherstone, Susan; Quick, Will; Lewis, Ari

2015-01-01

Biomass is increasingly being used for power generation; however, assessment of potential occupational health and safety (OH&S) concerns related to usage of biomass fuels in combustion-based generation remains limited. We reviewed the available literature on known and potential OH&S issues associated with biomass-based fuel usage for electricity generation at the utility scale. We considered three potential exposure scenarios—pre-combustion exposure to material associated with the fuel, exposure to combustion products, and post-combustion exposure to ash and residues. Testing of dust, fungal and bacterial levels at two power stations was also undertaken. Results indicated that dust concentrations within biomass plants can be extremely variable, with peak levels in some areas exceeding occupational exposure limits for wood dust and general inhalable dust. Fungal spore types, identified as common environmental species, were higher than in outdoor air. Our review suggests that pre-combustion risks, including bioaerosols and biogenic organics, should be considered further. Combustion and post-combustion risks appear similar to current fossil-based combustion. In light of limited available information, additional studies at power plants utilizing a variety of technologies and biomass fuels are recommended. PMID:26206568

Does acute radio-frequency electromagnetic field exposure affect visual event-related potentials in healthy adults?

PubMed

Dalecki, Anna; Loughran, Sarah P; Verrender, Adam; Burdon, Catriona A; Taylor, Nigel A S; Croft, Rodney J

2018-05-01

To use improved methods to address the question of whether acute exposure to radio-frequency (RF) electromagnetic fields (RF-EMF) affects early (80-200 ms) sensory and later (180-600 ms) cognitive processes as indexed by event-related potentials (ERPs). Thirty-six healthy subjects completed a visual discrimination task during concurrent exposure to a Global System for Mobile Communications (GSM)-like, 920 MHz signal with peak-spatial specific absorption rate for 10 g of tissue of 0 W/kg of body mass (Sham), 1 W/kg (Low RF) and 2 W/kg (High RF). A fully randomised, counterbalanced, double-blind design was used. P1 amplitude was reduced (p = .02) and anterior N1 latency was increased (p = .04) during Exposure compared to Sham. There were no effects on any other ERP latencies or amplitudes. RF-EMF exposure may affect early perceptual (P1) and preparatory motor (anterior N1) processes. However, only two ERP indices, out of 56 comparisons, were observed to differ between RF-EMF exposure and Sham, suggesting that these observations may be due to chance. These observations are consistent with previous findings that RF-EMF exposure has no reliable impact on cognition (e.g., accuracy and response speed). Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Low lifetime stress exposure is associated with reduced stimulus–response memory

PubMed Central

Goldfarb, Elizabeth V.; Shields, Grant S.; Daw, Nathaniel D.; Slavich, George M.; Phelps, Elizabeth A.

2017-01-01

Exposure to stress throughout life can cumulatively influence later health, even among young adults. The negative effects of high cumulative stress exposure are well-known, and a shift from episodic to stimulus–response memory has been proposed to underlie forms of psychopathology that are related to high lifetime stress. At the other extreme, effects of very low stress exposure are mixed, with some studies reporting that low stress leads to better outcomes, while others demonstrate that low stress is associated with diminished resilience and negative outcomes. However, the influence of very low lifetime stress exposure on episodic and stimulus–response memory is unknown. Here we use a lifetime stress assessment system (STRAIN) to assess cumulative lifetime stress exposure and measure memory performance in young adults reporting very low and moderate levels of lifetime stress exposure. Relative to moderate levels of stress, very low levels of lifetime stress were associated with reduced use and retention (24 h later) of stimulus–response (SR) associations, and a higher likelihood of using context memory. Further, computational modeling revealed that participants with low levels of stress exhibited worse expression of memory for SR associations than those with moderate stress. These results demonstrate that very low levels of stress exposure can have negative effects on cognition. PMID:28298555

Exposure of Athletic Trainers to Potentially Infectious Bodily Fluids in the High School Setting.

ERIC Educational Resources Information Center

Middlemas, David A.; Jessee, K. Brian; Mulder, Diane K.; Rehberg, Robb S.

1997-01-01

Examined high school athletic trainers' exposure to potentially infectious bodily fluids. Data on number of potential exposures per game and practice, number of athletes removed from competition for bleeding, and number of times athletes changed uniforms indicated that trainers had significant chances of being exposed to potentially infectious…

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

PubMed Central

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

2010-01-01

Background Detection of estrogens in the environment has raised concerns in recent years because of their potential to affect both wildlife and humans. Objectives We compared exposures to prescribed and naturally occurring estrogens in drinking water to exposures to naturally occurring background levels of estrogens in the diet of children and adults and to four independently derived acceptable daily intakes (ADIs) to determine whether drinking water intakes are larger or smaller than dietary intake or ADIs. Methods We used the Pharmaceutical Assessment and Transport Evaluation (PhATE) model to predict concentrations of estrogens potentially present in drinking water. Predicted drinking water concentrations were combined with default water intake rates to estimate drinking water exposures. Predicted drinking water intakes were compared to dietary intakes and also to ADIs. We present comparisons for individual estrogens as well as combined estrogens. Results In the analysis we estimated that a child’s exposures to individual prescribed estrogens in drinking water are 730–480,000 times lower (depending upon estrogen type) than exposure to background levels of naturally occurring estrogens in milk. A child’s exposure to total estrogens in drinking water (prescribed and naturally occurring) is about 150 times lower than exposure from milk. Adult margins of exposure (MOEs) based on total dietary exposure are about 2 times smaller than those for children. Margins of safety (MOSs) for an adult’s exposure to total prescribed estrogens in drinking water vary from about 135 to > 17,000, depending on ADI. MOSs for exposure to total estrogens in drinking water are about 2 times lower than MOSs for prescribed estrogens. Depending on the ADI that is used, MOSs for young children range from 28 to 5,120 for total estrogens (including both prescribed and naturally occurring sources) in drinking water. Conclusions The consistently large MOEs and MOSs strongly suggest that

Habitat Management to Reduce Human Exposure to Trypanosoma cruzi and Western Conenose Bugs (Triatoma protracta).

PubMed

Shender, Lisa; Niemela, Michael; Conrad, Patricia; Goldstein, Tracey; Mazet, Jonna

2016-09-01

Chagas disease, which manifests as cardiomyopathy and severe gastrointestinal dysfunction, is caused by Trypanosoma cruzi, a vector-borne parasite. In California, the vector Triatoma protracta frequently colonizes woodrat (Neotoma spp.) lodges, but may also invade nearby residences, feeding upon humans and creating the dual risk of bite-induced anaphylaxis and T. cruzi transmission. Our research aimed to assess T. cruzi presence in woodrats in a previously unstudied northern California area, statistically evaluate woodrat microhabitat use with respect to vegetation parameters, and provide guidance for habitat modifications to mitigate public health risks associated with Tr. protracta exposure. Blood samples from big-eared woodrats (N. macrotis) trapped on rural private properties yielded a T. cruzi prevalence of 14.3%. Microhabitat analyses suggest that modifying vegetation to reduce understory density within a 40 meter radius of human residences might minimize woodrat lodge construction within this buffer area, potentially decreasing human exposure to Tr. protracta.

Potential exposure to Australian bat lyssavirus in south east Queensland: what has changed in 12 years?

PubMed

Young, Megan K; McCall, Bradley J

2010-09-01

Public health measures have been targeting potential exposure to Australian bat lyssavirus (ABLV) since the first recognised human cases, more than a decade ago. The effect of these measures on the epidemiology of notifications of potential exposure has not been investigated since 2003. Trends in notifications of potential exposure to ABLV reported to the Brisbane Southside Public Health Unit between November 1996 and October 2008 were examined. During the study period notification rates declined among all population groups and potential exposures were notified more promptly. The proportion of female notifications and the proportion of notifications from volunteer bat carers and their families and professional groups decreased over time. These changes over 12 years may indicate success of public health measures, under-reporting of potential exposure or both. Intentional handling of bats by untrained members of the public continues to be an important source of potential exposure to ABLV and requires a sustained public health response.

Behavioral factors affecting exposure potential for household cleaning products.

PubMed

Kovacs, D C; Small, M J; Davidson, C I; Fischhoff, B

1997-01-01

Behavioral experiments were performed on 342 subjects to determine whether behavior, which could affect the level of personal exposure, is exhibited in response to odors and labels which are commonly used for household chemicals. Potential for exposure was assessed by having subjects perform cleaning tasks presented as a product preference test, and noting the amount of cleaning product used, the time taken to complete the cleaning task, the product preference, and the exhibition of avoidance behavior. Product odor was found to affect product preference in the study with the pleasant odored product being preferred to the neutral and unpleasant products. Product odor was also found to influence the amount of product used; less of the odored products was used compared to the neutral product. The experiment also found that very few of the subjects in the study read the product labels, precluding analysis of the effect of such labels on product use. A postexperiment questionnaire on household cleaning product purchasing and use was administered to participants. The results indicate that significant gender differences exist. Women in the sample reported more frequent purchase and use of cleaning products resulting in an estimated potential exposure 40% greater than for the men in the sample. This finding is somewhat countered by the fact that women more frequently reported exposure avoidance behavior, such as using gloves. Additional significant gender differences were found in the stated importance of product qualities, such as odor and environmental quality. This study suggests the need for further research, in a more realistic use setting, on the impact of public education, labels, and product odor on preference, use, and exposure for different types of consumer products.

Letter from Administrator Pruitt on Meeting to Reduce Childhood Lead Exposure

EPA Pesticide Factsheets

Administrator Pruitt has formally invited members of the President’s Task Force on Environmental Health Risks and Safety Risks to Children to participate in a meeting to discuss next steps in developing a federal strategy to reduce childhood lead exposure.

Prevalence of hazardous exposures in veterinary practice

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

Wiggins, P.; Schenker, M.B.; Green, R.

1989-01-01

All female graduates of a major U.S. veterinary school were surveyed by mailed questionnaire to obtain details of work practice and hazard exposure during the most recent year worked and during all pregnancies. Exposure questions were based on previously implicated occupational hazards which included anesthetic gases, radiation, zoonoses, prostaglandins, vaccines, physical trauma, and pesticides. The response rate was 86% (462/537). We found that practice type and pregnancy status were major determinants of hazard exposure within the veterinary profession. Small-animal practitioners reported the highest rates of exposure to anesthetic gas (94%), X-ray (90%), and pesticides (57%). Large-animal practitioners reported greater ratesmore » of trauma (64%) and potential exposure to prostaglandins (92%), Brucella abortus vaccine (23%), and carbon monoxide (18%). Potentially hazardous workplace practices or equipment were common. Forty-one percent of respondents who reported taking X-rays did not wear film badges, and 76% reported physically restraining animals for X-ray procedures. Twenty-seven percent of the respondents exposed to anesthetic gases worked at facilities which did not have waste anesthetic gas scavenging systems. Women who worked as veterinarians during a pregnancy attempted to reduce exposures to X-rays, insecticides, and other potentially hazardous exposures. Some potentially hazardous workplace exposures are common in veterinary practice, and measures to educate workers and to reduce these exposures should not await demonstration of adverse health effects.« less

Safeguarding Our Children at Home: Reducing Exposures to Toxic Chemicals and Heavy Metals

ERIC Educational Resources Information Center

Miller, Elise; Snow, Nancy

2005-01-01

Emerging research suggests that exposure to environmental pollutants, prenatally and in early childhood, may contribute significantly to diseases and disabilities. For example, exposures to mercury or lead early in life can impact the nervous system and brain, potentially contributing to learning, behavioral, and developmental disabilities. The…

Potential exposures associated with indoor marijuana growing operations.

PubMed

Martyny, John W; Serrano, Kate A; Schaeffer, Joshua W; Van Dyke, Mike V

2013-01-01

We entered a total of 30 indoor marijuana grow operations (IMGO) with law enforcement investigators in order to determine potential exposures to first responders. Samples for airborne fungal spores, volatile organic compounds, carbon dioxide, carbon monoxide, and delta-9-tetrahydrocannabinol (THC) were obtained as well as the identification of chemicals utilized in the IMGO. The chemicals utilized within the IMGOs were primarily pesticides and fertilizers with none showing high toxicity. Although several of the IMGOs had CO2 enrichment processes involving combustion, CO levels were not elevated. THC levels were identified on surfaces within the IMGOs and on the hands of the investigators. Surface levels ranged from <0.1 μg /100 cm(2) to 2000 μg /100 cm(2) with a geometric mean of 0.37 μg /100 cm(2). THC levels on the hands of officers ranged from <0.10 μg /wipe to 2900 μg /wipe with a geometric mean of 15 μg /wipe. These levels were not considered to be elevated to the point of causing a toxic exposure to responders. A total of 407 fungal spore samples were taken using both slit impactor plates and 400-hole impactors. Both methods identified elevated fungal spore levels, especially during the removal of plants from some of the IMGOs. After plant removal, spore counts increased to levels above 50,000 spores/m(3) with one sample over 500,000 spores/m(3). In addition, we found that there was a shift in species between indoor and outdoor samples with Cladosporium sp. the predominant outdoor species and Penicillium sp. the predominant indoor species. We concluded that the potential increase in fungal spore concentrations associated with the investigation and especially removal of the marijuana plants could potentially expose responders to levels of exposure consistent with those associated with mold remediation processes and that respiratory protection is advisable.

Exposure to Ergot Alkaloids During Gestation Reduces Fetal Growth in Sheep

NASA Astrophysics Data System (ADS)

Duckett, Susan; Pratt, Scott; Andrae, John

2014-08-01

Tall fescue [Lolium arundinaceum (Schreb.) Darbysh; Schedonorus phoenix (Scop.) Holub] is the primary cool season perennial grass in the eastern U.S. Most tall fescue contains an endophyte (Neotyphodium coenophialum), which produces ergot alkaloids that cause vasoconstriction and could restrict blood flow to the fetus in pregnant animals. The objective of this study was to examine fetal growth during maternal exposure to ergot alkaloids during gestation. Pregnant ewes (n = 16) were randomly assigned to one of two dietary treatments: 1) endophyte-infected (Neotyphodium coenophialum) tall fescue seed (E+; 0.8 ug of ergovaline /g diet DM) and 2) endophyte-free tall fescue seed (E-; 0.0 ug of ergovaline/g diet DM). Birth weight of lambs was reduced by 37% for E+ compared to E-. Organ and muscle weights were also lighter for E+ than E-. Exposure to ergot alkaloids in utero reduces fetal growth and muscle development.

Effectiveness of interventions to reduce flour dust exposures in supermarket bakeries in South Africa.

PubMed

Baatjies, Roslynn; Meijster, Tim; Heederik, Dick; Sander, Ingrid; Jeebhay, Mohamed F

2014-12-01

A recent study of supermarket bakery workers in South Africa demonstrated that 25% of workers were sensitised to flour allergens and 13% had baker's asthma. Evidence on exposure reduction strategies using specifically designed interventions aimed at reducing the risk of baker's asthma is scarce. The aim of this study was to evaluate the effectiveness of different control measures to reduce airborne flour dust exposure using a randomised design. A group-randomised study design was used to assign 30 bakeries of a large supermarket chain store to two intervention groups and a control group, of which 15 bakeries were studied. Full-shift environmental personal samples were used to characterise exposure to flour dust and wheat and rye allergens levels pre-intervention (n=176) and post-intervention (n=208). The overall intervention effect revealed a 50% decrease in mean flour dust, wheat and rye allergen exposure. The reduction in exposure was highest for managers (67%) and bakers (47%), and lowest for counterhands (23%). For bakers, the greatest reduction in flour dust was associated with control measures such as the use of the mixer lid (67%), divider oil (63%) or focused training (54%). However, the greatest reduction (80%) was observed when using a combination of all control measures. A specially designed intervention strategy reduced both flour dust and allergen levels. Best results were observed when combining both engineering controls and training. Further studies will investigate the long-term health impact of these interventions on reducing the disease burden among this group of bakers. 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.

The Potential Neurotoxic Effects of Low-Dose Sarin Exposure in a Guinea Pig Model

DTIC Science & Technology

2002-01-01

1 THE POTENTIAL NEUROTOXIC EFFECTS OF LOW-DOSE SARIN EXPOSURE IN A GUINEA PIG MODEL Melinda R. Roberson, PhD, Michelle B. Schmidt...Proving Ground, MD 21010 USA ABSTRACT This study is assessing the effects in guinea pigs of repeated low-dose exposure to the nerve...COVERED - 4. TITLE AND SUBTITLE The Potential Neurotoxic Effects Of Low-Dose Sarin Exposure In A Guinea Pig Model 5a. CONTRACT NUMBER 5b

Assessment of potential asbestos exposures from jet engine overhaul work.

PubMed

Mlynarek, S P; Van Orden, D R

2012-06-01

Asbestos fibers have been used in a wide variety of products and numerous studies have shown that exposures from the use or manipulation of these products can vary widely. Jet engines contained various components (gaskets, clamps, o-rings and insulation) that contained asbestos that potentially could release airborne fibers during routine maintenance or during an engine overhaul. To evaluate the potential exposures to aircraft mechanics, a Pratt & Whitney JT3D jet engine was obtained and overhauled by experienced mechanics using tools and work practices similar to those used since the time this engine was manufactured. This study has demonstrated that the disturbance of asbestos-containing gaskets, o-rings, and other types of asbestos-containing components, while performing overhaul work to a jet engine produces very few airborne fibers, and that virtually none of these aerosolized fibers is asbestos. The overhaul work was observed to be dirty and oily. The exposures to the mechanics and bystanders were several orders of magnitude below OSHA exposure regulations, both current and historic. The data presented underscore the lack of risk to the health of persons conducting this work and to other persons in proximity to it from airborne asbestos. Copyright © 2012 Elsevier Inc. All rights reserved.

Conservation of body calcium by increased dietary intake of potassium: A potential measure to reduce the osteoporosis process during prolonged exposure to microgravity

NASA Technical Reports Server (NTRS)

Nechay, Bohdan R.

1989-01-01

During the 1988 NASA Summer Faculty Fellowship Program, it was proposed that the loss of skeletal calcium upon prolonged exposure to microgravity could be explained, in part, by a renal maladjustment characterized by an increased urinary excretion of calcium. It was theorized that because the conservation of body fluids and electrolytes depends upon the energy of adenosine triphosphate and enzymes that control the use of its energy for renal ion transport, an induction of renal sodium and potassium-dependent adenosine triphosphatase (Na + K ATPase) by oral loading with potassium would increase the reabsorption of sodium directly and that of calcium indirectly, leading to improved hydration and to reduced calcium loss. Preliminary studies showed the following. Rats drinking water containing 0.2 M potassium chloride for six to 13 days excreted in urine 22 muEq of calcium and 135 muEq of sodium per 100 grams of body weight per day. The corresponding values for control rats drinking tap water were 43 muEq and 269 muEq respectively. Renal Na + K ATPase activity in potassium loaded rats was higher than in controls. Thus, oral potassium loading resulted in increased Na + K ATPase activity and diminished urinary excretion of calcium and of sodium as predicted by the hypothesis. An extension of these studies to humans has the potential of resulting in development of harmless, non-invasive, drug-free, convenient measures to reduce bone loss and other electrolyte and fluid problems in space travelers exposed to prolonged periods of microgravity.

Reducing sound and light exposure to improve sleep on the adult intensive care unit: An inclusive narrative review.

PubMed

Bion, Victoria; Lowe, Alex Sw; Puthucheary, Zudin; Montgomery, Hugh

2018-05-01

Sleep disturbance is common in intensive care units. It is associated with detrimental psychological impacts and has potential to worsen outcome. Irregular exposure to sound and light may disrupt circadian rhythm and cause frequent arousals from sleep. We sought to review the efficacy of environmental interventions to reduce sound and light exposure with the aim of improving patient sleep on adult intensive care units. We searched both PubMed (1966-30 May 2017) and Embase (1974-30 May 2017) for all relevant human (adult) studies and meta-analyses published in English using search terms ((intensive care OR critical care), AND (sleep OR sleep disorders), AND (light OR noise OR sound)). Bibliographies were explored. Articles were included if reporting change in patient sleep in response to an intervention to reduce disruptive intensive care unit sound /light exposure. Fifteen studies were identified. Nine assessed mechanical interventions, four of which used polysomnography to assess sleep. Five studies looked at environmental measures to facilitate sleep and a further two (one already included as assessing a mechanical intervention) studied the use of sound to promote sleep. Most studies found a positive impact of the intervention on sleep. However, few studies used objective sleep assessments, sample sizes were small, methodologies sometimes imperfect and analysis limited. Data are substantially derived from specialist (neurosurgical, post-operative, cardiothoracic and cardiological) centres. Patients were often at the 'less sick' end of the spectrum in a variety of settings (open ward beds or side rooms). Simple measures to reduce intensive care unit patient sound/light exposure appear effective. However, larger and more inclusive high-quality studies are required in order to identify the measures most effective in different patient groups and any impacts on outcome.

Prolonged head-down tilt exposure reduces maximal cutaneous vasodilator and sweating capacity in humans

NASA Technical Reports Server (NTRS)

Crandall, C. G.; Shibasaki, M.; Wilson, T. E.; Cui, J.; Levine, B. D.

2003-01-01

Cutaneous vasodilation and sweat rate are reduced during a thermal challenge after simulated and actual microgravity exposure. The effects of microgravity exposure on cutaneous vasodilator capacity and on sweat gland function are unknown. The purpose of this study was to test the hypothesis that simulated microgravity exposure, using the 6 degrees head-down tilt (HDT) bed rest model, reduces maximal forearm cutaneous vascular conductance (FVC) and sweat gland function and that exercise during HDT preserves these responses. To test these hypotheses, 20 subjects were exposed to 14 days of strict HDT bed rest. Twelve of those subjects exercised (supine cycle ergometry) at 75% of pre-bed rest heart rate maximum for 90 min/day throughout HDT bed rest. Before and after HDT bed rest, maximal FVC was measured, via plethysmography, by heating the entire forearm to 42 degrees C for 45 min. Sweat gland function was assessed by administering 1 x 10(-6) to 2 M acetylcholine (9 doses) via intradermal microdialysis while simultaneously monitoring sweat rate over the microdialysis membranes. In the nonexercise group, maximal FVC and maximal stimulated sweat rate were significantly reduced after HDT bed rest. In contrast, these responses were unchanged in the exercise group. These data suggest that 14 days of simulated microgravity exposure, using the HDT bed rest model, reduces cutaneous vasodilator and sweating capacity, whereas aerobic exercise training during HDT bed rest preserves these responses.

Does Switching to Reduced Ignition Propensity Cigarettes Alter Smoking Behavior or Exposure to Tobacco Smoke Constituents?

PubMed Central

Rees, Vaughan W.; Norton, Kaila J.; Cummings, K. Michael; Connolly, Gregory N.; Alpert, Hillel R.; Sjödin, Andreas; Romanoff, Lovisa; Li, Zheng; June, Kristie M.; Giovino, Gary A.

2010-01-01

Introduction: Since 2004, several jurisdictions have mandated that cigarettes show reduced ignition propensity (RIP) in laboratory testing. RIP cigarettes may limit fires caused by smoldering cigarettes, reducing fire-related deaths and injury. However, some evidence suggests that RIP cigarettes emit more carbon monoxide and polycyclic aromatic hydrocarbons, and smokers may alter their smoking patterns in response to RIP cigarettes. Both of these could increase smokers’ exposures to harmful constituents in cigarettes. Methods: An 18-day switching study with a comparison group was conducted in Boston, MA (N = 77), and Buffalo, NY (N = 83), in 2006–2007. Current daily smokers completed 4 laboratory visits and two 48-hr field data collections. After a 4-day baseline, Boston participants switched to RIP cigarettes for 14 days, whereas Buffalo participants smoked RIP cigarettes throughout. Outcome measures included cigarettes smoked per day; smoking topography; salivary cotinine; breath CO; and hydroxylated metabolites of pyrene, naphthalene, phenanthrene, and fluorene. Because the groups differed demographically, analyses adjusted for race, age, and sex. Results: We observed no significant changes in smoking topography or CO exposure among participants who switched to RIP cigarettes. Cigarette use decreased significantly in the switched group (37.7 cigarettes/48 hr vs. 32.6 cigarettes/48 hr, p = .031), while hydroxyphenanthrenes increased significantly (555 ng/g creatinine vs. 669 ng/g creatinine, p = .007). No other biomarkers were significantly affected. Discussion: Small increases in exposure to phenanthrene among smokers who switched to RIP versions were observed, while other exposures and smoking topography were not significantly affected. Toxicological implications of these findings are unclear. These findings should be weighed against the potential public health benefits of adopting RIP design standards for cigarette products. PMID:20805292

Feedback on Measured Dust Concentrations Reduces Exposure Levels Among Farmers.

PubMed

Basinas, Ioannis; Sigsgaard, Torben; Bønløkke, Jakob Hjort; Andersen, Nils Testrup; Omland, Øyvind; Kromhout, Hans; Schlünssen, Vivi

2016-08-01

The high burden of exposure to organic dust among livestock farmers warrants the establishment of effective preventive and exposure control strategies for these workers. The number of intervention studies exploring the effectiveness of exposure reduction strategies through the use of objective measurements has been limited. To examine whether dust exposure can be reduced by providing feedback to the farmers concerning measurements of the exposure to dust in their farm. The personal dust levels of farmers in 54 pig and 26 dairy cattle farms were evaluated in two measurement series performed approximately 6 months apart. Detailed information on work tasks and farm characteristics during the measurements were registered. Participating farms were randomized a priori to a control (n = 40) and an intervention group (n = 40). Shortly after the first visit, owners of intervention farms only received a letter with information on the measured dust concentrations in the farm together with some general advises on exposure reduction strategies (e.g. use of respirators during certain tasks). Relationships between measured dust concentrations and intervention status were quantified by means of linear mixed effect analysis with farm and worker id as random effects. Season, type of farming, and work tasks were treated as fixed effects. Changes in exposure over time were explored primarily at a farm level in models combined, as well as separate for pig and cattle farmers. After adjustment for fixed effects, an overall reduction of 23% in personal dust exposures was estimated as a result of the intervention (P = 0.02). Exposure reductions attributable to the intervention were similar across pig and cattle farmers, but statistically significant only for pig farmers. Intervention effects among pig farmers did not depend on the individuals' information status; but among cattle farmers a significant 48% reduction in exposure was found only among individuals that reported to have been

Reducing Pb poisoning in birds and Pb exposure in game meat consumers: the dual benefit of effective Pb shot regulation.

PubMed

Mateo, Rafael; Vallverdú-Coll, Núria; López-Antia, Ana; Taggart, Mark A; Martínez-Haro, Monica; Guitart, Raimon; Ortiz-Santaliestra, Manuel E

2014-02-01

The use of lead (Pb) ammunition in the form of shot pellets has been identified as a Pb exposure risk in wildlife and their human consumers. We explore the hypothesis that Pb shot ban enforcement reduces the risk of avian Pb poisoning as well as Pb exposure in game meat consumers. We assessed compliance with a partial ban on Pb shot commencing in 2003 by examination of 937 waterbirds harvested by hunters between 2007 and 2012 in the Ebro delta (Spain). Prevalence of Pb shot ingestion was determined, as were Pb concentrations in liver and muscle tissue to evaluate the potential for Pb exposure in game meat consumers. Hunted birds with only embedded Pb shot (no steel) declined from 26.9% in 2007-08 to <2% over the following three hunting seasons after ban reinforcement. Pb shot ingestion in mallards decreased from a pre-ban value of 30.2% to 15.5% in the post-ban period. Liver Pb levels were predominantly defined by the presence of ingested shot, whereas muscle levels were defined by the presence of both ingested and embedded shot. Only 2.5% of mallard muscle tissue had Pb levels above European Union regulations for meat (0.1μg/g wet weight) in the 2008-09 season, when Pb shot ingestion prevalence was also at a minimum (5.1%). Effective restrictions in Pb ammunition use have a dual benefit since this reduces Pb exposure for game meat consumers due to embedded ammunition as well as reducing Pb poisoning in waterbirds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sun Exposure and Its Effects on Human Health: Mechanisms through Which Sun Exposure Could Reduce the Risk of Developing Obesity and Cardiometabolic Dysfunction

PubMed Central

Fleury, Naomi; Geldenhuys, Sian; Gorman, Shelley

2016-01-01

Obesity is a significant burden on global healthcare due to its high prevalence and associations with chronic health conditions. In our animal studies, ongoing exposure to low dose ultraviolet radiation (UVR, found in sunlight) reduced weight gain and the development of signs of cardiometabolic dysfunction in mice fed a high fat diet. These observations suggest that regular exposure to safe levels of sunlight could be an effective means of reducing the burden of obesity. However, there is limited knowledge around the nature of associations between sun exposure and the development of obesity and cardiometabolic dysfunction, and we do not know if sun exposure (independent of outdoor activity) affects the metabolic processes that determine obesity in humans. In addition, excessive sun exposure has strong associations with a number of negative health consequences such as skin cancer. This means it is very important to “get the balance right” to ensure that we receive benefits without increasing harm. In this review, we detail the evidence around the cardiometabolic protective effects of UVR and suggest mechanistic pathways through which UVR could be beneficial. PMID:27727191

Potential Health Effects Associated with Dermal Exposure to Occupational Chemicals

PubMed Central

Anderson, Stacey E; Meade, B Jean

2014-01-01

There are a large number of workers in the United States, spanning a variety of occupational industries and sectors, who are potentially exposed to chemicals that can be absorbed through the skin. Occupational skin exposures can result in numerous diseases that can adversely affect an individual’s health and capacity to perform at work. In general, there are three types of chemical–skin interactions of concern: direct skin effects, immune-mediated skin effects, and systemic effects. While hundreds of chemicals (metals, epoxy and acrylic resins, rubber additives, and chemical intermediates) present in virtually every industry have been identified to cause direct and immune-mediated effects such as contact dermatitis or urticaria, less is known about the number and types of chemicals contributing to systemic effects. In an attempt to raise awareness, skin notation assignments communicate the potential for dermal absorption; however, there is a need for standardization among agencies to communicate an accurate description of occupational hazards. Studies have suggested that exposure to complex mixtures, excessive hand washing, use of hand sanitizers, high frequency of wet work, and environmental or other factors may enhance penetration and stimulate other biological responses altering the outcomes of dermal chemical exposure. Understanding the hazards of dermal exposure is essential for the proper implementation of protective measures to ensure worker safety and health. PMID:25574139

Potential health effects associated with dermal exposure to occupational chemicals.

PubMed

Anderson, Stacey E; Meade, B Jean

2014-01-01

There are a large number of workers in the United States, spanning a variety of occupational industries and sectors, who are potentially exposed to chemicals that can be absorbed through the skin. Occupational skin exposures can result in numerous diseases that can adversely affect an individual's health and capacity to perform at work. In general, there are three types of chemical-skin interactions of concern: direct skin effects, immune-mediated skin effects, and systemic effects. While hundreds of chemicals (metals, epoxy and acrylic resins, rubber additives, and chemical intermediates) present in virtually every industry have been identified to cause direct and immune-mediated effects such as contact dermatitis or urticaria, less is known about the number and types of chemicals contributing to systemic effects. In an attempt to raise awareness, skin notation assignments communicate the potential for dermal absorption; however, there is a need for standardization among agencies to communicate an accurate description of occupational hazards. Studies have suggested that exposure to complex mixtures, excessive hand washing, use of hand sanitizers, high frequency of wet work, and environmental or other factors may enhance penetration and stimulate other biological responses altering the outcomes of dermal chemical exposure. Understanding the hazards of dermal exposure is essential for the proper implementation of protective measures to ensure worker safety and health.

Biomarkers of Acute Respiratory Allergen Exposure: Screening For Sensitization Potential

EPA Science Inventory

Rationale: An in vitro assay to identify respiratory sensitizers will provide a rapid screen and reduce animal use. The study goal was to identify biomarkers that differentiate allergen versus non-allergen responses following an acute exposure. Methods: Female BALB/c mice rec...

Evaluation of Potential Exposure to Metals in Laundered Shop Towels

PubMed Central

Greenberg, Grace; Beck, Barbara D.

2013-01-01

We reported in 2003 that exposure to metals on laundered shop towels (LSTs) could exceed toxicity criteria. New data from LSTs used by workers in North America document the continued presence of metals in freshly laundered towels. We assessed potential exposure to metals based on concentrations of metals on the LSTs, estimates of LST usage by employees, and the transfer of metals from LST-to-hand, hand-to-mouth, and LST-to-lip, under average- or high-exposure scenarios. Exposure estimates were compared to toxicity criteria. Under an average-exposure scenario (excluding metals' data outliers), exceedances of the California Environmental Protection Agency, U.S. Environmental Protection Agency, and the Agency for Toxic Substances and Disease Registry toxicity criteria may occur for aluminum, cadmium, cobalt, copper, iron, and lead. Calculated intakes for these metals were up to more than 400-fold higher (lead) than their respective toxicity criterion. For the high-exposure scenario, additional exceedances may occur, and high-exposure intakes were up to 1,170-fold higher (lead) than their respective toxicity criterion. A sensitivity analysis indicated that alternate plausible assumptions could increase or decrease the magnitude of exceedances, but were unlikely to eliminate certain exceedances, particularly for lead. PMID:24453472

Phytotechnologies – Preventing Exposures, Improving Public Health

PubMed Central

Henry, Heather F.; Burken, Joel G.; Maier, Raina M.; Newman, Lee A.; Rock, Steven; Schnoor, Jerald L.; Suk, William A.

2014-01-01

Phytotechnologies have the potential to reduce the amount and/or toxicity of deleterious chemicals/agents, and thereby, prevent human exposures to hazardous substances. As such, phytotechnologies are a tool for primary prevention within the context of public health. Research advances demonstrate that phytotechnologies can be uniquely tailored for effective exposure prevention for a variety of applications. In addition to exposure prevention, phytotechnologists have advanced the use of plants as sensors to delineate environmental contaminants and potential exposures. The applications presented in this paper are at various stages of development and are presented in a framework to reflect how phytotechnologies can help meet basic public health needs for access to clean water, air, and food resources. As plant-based technologies can often be integrated into communities at minimal cost and with low infrastructure needs, their use in improving environmental quality can be applied broadly to minimize potential contaminant exposure. These natural treatment systems concurrently provide ecosystem services of notable value to communities and society. In the future, integration and coordination of phytotechnology activities with public health research will allow technology development that focuses on prevention of environmental exposures. Such an approach will lead to an important role of phytotechnologies in providing sustainable solutions to environmental exposure challenges that improve public health and potentially reduce the burden of disease. PMID:23819283

Use of the posteroanterior projection: a method of reducing x-ray exposure to specific radiosensitive organs

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

Frank, E.D.; Stears, J.G.; Gray, J.E.

The posteroanterior projection was studied to determine if it could be a substitute for the commonly used anteroposterior projection as a method of reducing x-ray exposure to specific radiosensitive organs during intracranial tomography and scoliosis radiography. The use of the posteroanterior projection resulted in a reduction of 95% in exposure to the lens of the eye during intracranial tomography and of more than 90% to the thyroid, sternum, and breasts during scoliosis radiography. In addition to the major reduction in radiation exposure, the diagnostic capability of the examination was not reduced and comfort in most patients was not affected.

Passive control potentials of trees and on-street parked cars in reduction of air pollution exposure in urban street canyons.

PubMed

Abhijith, K V; Gokhale, Sharad

2015-09-01

This study investigates the passive-control-potentials of trees and on-street parked cars on pedestrian exposure to air pollutants in a street canyon using three-dimensional CFD. Since, according to some studies trees deteriorate air quality and cars parked roadside improve it, the combine as well as separate effects of trees and on-street parked cars have been examined. For this, different tree canopy layouts and parking configurations have been developed and pedestrian exposure for each has been analysed. The results showed, for example, tree crown with high porosity and low-stand density in combination with parallel or perpendicular car parking reduced the pedestrian exposure considerably. Copyright © 2015 Elsevier Ltd. All rights reserved.

Embryonic-only arsenic exposure in killifish (Fundulus heteroclitus) reduces growth and alters muscle IGF levels one year later.

PubMed

Szymkowicz, Dana B; Sims, Kaleigh C; Castro, Noemi M; Bridges, William C; Bain, Lisa J

2017-05-01

Arsenic is a contaminant of drinking water and crops in many parts of the world. Epidemiological studies have shown that arsenic exposure is linked to decreased birth weight, weight gain, and proper skeletal muscle function. The goal of this study was to use killifish (Fundulus heteroclitus) as a model to determine the long-term effects of embryonic-only arsenic exposure on muscle growth and the insulin-like growth factor (IGF) pathway. Killifish embryos were exposed to 0, 50, 200 or 800ppb As III from fertilization until hatching. Juvenile fish were reared in clean water and muscle samples were collected at 16, 28, 40 and 52 weeks of age. There were significant reductions in condition factors, ranging from 12 to 17%, in the fish exposed to arsenic at 16, 28 and 40 weeks of age. However, by 52 weeks, no significant changes in condition factors were seen. Alterations in IGF-1R and IGF-1 levels were assessed as a potential mechanism by which growth was reduced. While there no changes in hepatic IGF-1 transcripts, skeletal muscle cells can also produce their own IGF-1 and/or alter IGF-1 receptor levels to help enhance growth. After a 200 and 800ppb embryonic exposure, fish grown in clean water for 16 weeks had IGF-1R transcripts that were 2.8-fold and 2-fold greater, respectively, than unexposed fish. Through 40 weeks of age, IGF1-R remained elevated in the 200ppb and 800ppb embryonic exposure groups by 1.8-3.9-fold, while at 52 weeks of age, IGF-1R levels were still significantly increased in the 800ppb exposure group. Skeletal muscle IGF-1 transcripts were also significantly increased by 1.9-5.1 fold through the 52 weeks of grow-out in clean by water in the 800ppb embryonic exposure group. Based on these results, embryonic arsenic exposure has long-term effects in that it reduces growth and increases both IGF-1 and IGF-1R levels in skeletal muscle even 1year after the exposure has ended. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessing the Health and Performance Risks of Reduced Carbon Dioxide Exposures and Resource Utilization

NASA Technical Reports Server (NTRS)

James, John T.

2012-01-01

There have been a cluster of anecdotal reports that ISS crews are experiencing adverse health effects from on orbit exposure to CO2 levels well below the current Spacecraft Maximum Allowable Concentration (SMAC), which is 5.3 mmHg for 180 days of exposure. Developing evidence that this standard should be reduced to protect crew health is not a simple process. Dr. John James' team looked at the reports of headaches by the crew during private medical conferences and matched these with CO2 levels around the time of these reports. They then compared these to CO2 levels when there were no reports of headache. Using benchmark dose modeling, they found that the risk of headache could be predicted in concentration ranges from 2 to 5 mmHg. However, the data are incomplete because there were insufficient data when crews were exposed to concentrations below 2 mmHg. James' team also asked whether neuro-cognitive effects could be identified with CO2 exposure levels and found that these could not be associated with CO2 levels. Finally, they addressed the question of resource use to meet various levels of CO2 control if the SMACs were lowered. They estimated that CO2 restrictions approaching 2 mmHg would require substantial increases in power use and up-mass resources. They are refining their data on CO2 and headaches, and are looking at potential interactions of intracranial pressure and CO2 levels in eliciting ocular effects.

Evaluation of Furfuryl Alcohol Sensitization Potential Following Dermal and Pulmonary Exposure: Enhancement of Airway Responsiveness

PubMed Central

Franko, Jennifer; Jackson, Laurel G.; Hubbs, Ann; Kashon, Michael; Meade, B. J.; Anderson, Stacey E.

2015-01-01

Furfuryl alcohol is considered by the U.S. Environmental Protection Agency to be a high volume production chemical, with over 1 million pounds produced annually. Due to its high production volume and its numerous industrial and consumer uses, there is considerable potential for work-related exposure, as well as exposure to the general population, through pulmonary, oral, and dermal routes of exposure. Human exposure data report a high incidence of asthma in foundry mold workers exposed to furan resins, suggesting potential immunologic effects. Although furfuryl alcohol was nominated and evaluated for its carcinogenic potential by the National Toxicology Program, studies evaluating its immunotoxicity are lacking. The studies presented here evaluated the immunotoxic potential of furfuryl alcohol following exposure by the dermal and pulmonary routes using a murine model. When tested in a combined irritancy local lymph node assay, furfuryl alcohol was identified to be an irritant and mild sensitizer (EC3 = 25.6%). Pulmonary exposure to 2% furfuryl alcohol resulted in enhanced airway hyperreactivity, eosinophilic infiltration into the lungs, and enhanced cytokine production (IL-4, IL-5, and interferon-γ) by ex vivo stimulated lung-associated draining lymphoid cells. Airway hyperreactivity and eosinophilic lung infiltration were augmented by prior dermal exposure to furfuryl alcohol. These results suggest that furfuryl alcohol may play a role in the development of allergic airway disease and encourage the need for additional investigation. PMID:22003193

ISSUES IN DERMAL EXPOSURE OF INFANTS

EPA Science Inventory

Infants' dermal exposures to environmental contaminants are expected to be different and, in many cases, much higher than adults. Because of the potential importance of the dermal exposure route, there is currently a significant amount of work being conducted to reduce the uncer...

Beating oxygen: chronic anoxia exposure reduces mitochondrial F1FO-ATPase activity in turtle (Trachemys scripta) heart

PubMed Central

Galli, Gina L. J.; Lau, Gigi Y.; Richards, Jeffrey G.

2013-01-01

SUMMARY The freshwater turtle Trachemys scripta can survive in the complete absence of O2 (anoxia) for periods lasting several months. In mammals, anoxia leads to mitochondrial dysfunction, which culminates in cellular necrosis and apoptosis. Despite the obvious clinical benefits of understanding anoxia tolerance, little is known about the effects of chronic oxygen deprivation on the function of turtle mitochondria. In this study, we compared mitochondrial function in hearts of T. scripta exposed to either normoxia or 2 weeks of complete anoxia at 5°C and during simulated acute anoxia/reoxygenation. Mitochondrial respiration, electron transport chain activities, enzyme activities, proton conductance and membrane potential were measured in permeabilised cardiac fibres and isolated mitochondria. Two weeks of anoxia exposure at 5°C resulted in an increase in lactate, and decreases in ATP, glycogen, pH and phosphocreatine in the heart. Mitochondrial proton conductance and membrane potential were similar between experimental groups, while aerobic capacity was dramatically reduced. The reduced aerobic capacity was the result of a severe downregulation of the F1FO-ATPase (Complex V), which we assessed as a decrease in enzyme activity. Furthermore, in stark contrast to mammalian paradigms, isolated turtle heart mitochondria endured 20 min of anoxia followed by reoxygenation without any impact on subsequent ADP-stimulated O2 consumption (State III respiration) or State IV respiration. Results from this study demonstrate that turtle mitochondria remodel in response to chronic anoxia exposure and a reduction in Complex V activity is a fundamental component of mitochondrial and cellular anoxia survival. PMID:23926310

Pulsed Electromagnetic Field Exposure Reduces Hypoxia and Inflammation Damage in Neuron-Like and Microglial Cells.

PubMed

Vincenzi, Fabrizio; Ravani, Annalisa; Pasquini, Silvia; Merighi, Stefania; Gessi, Stefania; Setti, Stefania; Cadossi, Ruggero; Borea, Pier Andrea; Varani, Katia

2017-05-01

In the present study, the effect of low-frequency, low-energy pulsed electromagnetic fields (PEMFs) has been investigated by using different cell lines derived from neuron-like cells and microglial cells. In particular, the primary aim was to evaluate the effect of PEMF exposure in inflammation- and hypoxia-induced injury in two different neuronal cell models, the human neuroblastoma-derived SH-SY5Y cells and rat pheochromocytoma PC12 cells and in N9 microglial cells. In neuron-like cells, live/dead and apoptosis assays were performed in hypoxia conditions from 2 to 48 h. Interestingly, PEMF exposure counteracted hypoxia damage significantly reducing cell death and apoptosis. In the same cell lines, PEMFs inhibited the activation of the hypoxia-inducible factor 1α (HIF-1α), the master transcriptional regulator of cellular response to hypoxia. The effect of PEMF exposure on reactive oxygen species (ROS) production in both neuron-like and microglial cells was investigated considering their key role in ischemic injury. PEMFs significantly decreased hypoxia-induced ROS generation in PC12, SH-SY5Y, and N9 cells after 24 or 48 h of incubation. Moreover, PEMFs were able to reduce some of the most well-known pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-8 release in N9 microglial cells stimulated with different concentrations of LPS for 24 or 48 h of incubation time. These results show a protective effect of PEMFs on hypoxia damage in neuron-like cells and an anti-inflammatory effect in microglial cells suggesting that PEMFs could represent a potential therapeutic approach in cerebral ischemic conditions. J. Cell. Physiol. 232: 1200-1208, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Socioeconomic, demographic and smoking-related correlates of the use of potentially reduced exposure to tobacco products in a national sample.

PubMed

Shaikh, Raees A; Siahpush, Mohammad; Singh, Gopal K

2014-07-01

In recent years, new non-traditional, potentially reduced exposure products (PREPs), claiming to contain fewer harmful chemicals than the traditional products, have been introduced in the market. Little is known about socioeconomic, demographic and smoking-related determinants of the likelihood of using these products among smokers. The aim of this study was to examine these determinants. Data from the 2006-2007 Tobacco Use Supplement to the Current Population Survey was used. We limited the analysis to current smokers (n=40724). Multivariate logistic regression analyses were conducted to estimate the association between covariates and the probability of the use of PREPs. We found that younger age, lower education, higher nicotine addiction and having an intention to quit are associated with higher likelihood of the use of PREPs. The likelihood of using these products was found to be higher among respondents who are unemployed or have a service, production, sales or farming occupation than those with a professional occupation. Smokers living in the midwest, south or west, were found to have a greater likelihood of the use of PREPs than those living in the northeast. Because there is little evidence to suggest that PREPs are less harmful that other tobacco products, their marketing as harm-minimising products should be regulated. Smokers, in particular those who are younger, have a lower socioeconomic status, and are more nicotine-dependent, should be the target of educational programmes that reveal the actual harm of PREPs. 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.

Trichloroethylene Exposure Reduces Liver Injury in a Mouse Model of Primary Biliary Cholangitis

PubMed Central

Ray, Jessica L.; Kopec, Anna K.; Joshi, Nikita; Cline-Fedewa, Holly; Lash, Lawrence H.; Williams, Kurt J.; Leung, Patrick S.; Gershwin, M. Eric

2017-01-01

Abstract Trichloroethylene (TCE) is a persistent environmental contaminant proposed to contribute to autoimmune disease. Experimental studies in lupus-prone MRL+/+ mice have suggested that TCE exposure can trigger autoimmune hepatitis. The vast majority of studies examining the connection between TCE and autoimmunity utilize this model, and the impact of TCE exposure in other established models of autoimmune liver disease is not known. We tested the hypothesis that TCE exposure exacerbates experimental hepatic autoimmunity in dominant negative transforming growth factor beta receptor type II (dnTGFBRII) mice, which develop serological and histological features resembling human primary biliary cholangitis. Female 8-week-old wild-type and dnTGFBRII mice were exposed to TCE (0.5 mg/ml) or vehicle (1% ethoxylated castor oil) in the drinking water for 12 or 22 weeks. Liver histopathology in 20- and 30-week-old wild-type mice was unremarkable irrespective of treatment. Mild portal inflammation was observed in vehicle-exposed 20-week-old dnTGFBRII mice and was not exacerbated by TCE exposure. Vehicle-exposed 30-week-old dnTGFBRII mice developed anti-mitochondrial antibodies, marked hepatic inflammation with necrosis, and hepatic accumulation of both B and T lymphocytes. To our surprise, TCE exposure dramatically reduced hepatic parenchymal inflammation and injury in 30-week-old dnTGFBRII mice, reflected by changes in hepatic proinflammatory gene expression, serum chemistry, and histopathology. Interestingly, TCE did not affect hepatic B cell accumulation or induction of the anti-inflammatory cytokine IL10. These data indicate that TCE exposure reduces autoimmune liver injury in female dnTGFBRII mice and suggests that the precise effect of environmental chemicals in autoimmunity depends on the experimental model. PMID:28115651

Perceptual Individuation Training (but not Mere Exposure) Reduces Implicit Racial Bias in Preschool Children

PubMed Central

Qian, Miao K.; Quinn, Paul C.; Heyman, Gail D.; Pascalis, Olivier; Fu, Genyue; Lee, Kang

2017-01-01

Two studies with preschool-age children examined the effectiveness of perceptual individuation training at reducing racial bias (Study 1, N = 32; Study 2, N = 56). We found that training preschool-age children to individuate other-race faces resulted in a reduction in implicit racial bias while mere exposure to other-race faces produced no such effect. We also showed that neither individuation training nor mere exposure reduced explicit racial bias. Theoretically, our findings provide strong evidence for a causal link between individual-level face processing and implicit racial bias, and are consistent with the newly proposed Perceptual-Social Linkage Hypothesis. Practically, our findings suggest that offering children experiences that allow them to increase their expertise in processing individual other-race faces will help reduce their implicit racial bias. PMID:28459274

Development of acute exposure guideline levels for airborne exposures to hazardous substances.

PubMed

Krewski, Daniel; Bakshi, Kulbir; Garrett, Roger; Falke, Ernest; Rusch, George; Gaylor, David

2004-04-01

Hazardous substances can be released into the atmosphere due to industrial and transportation accidents, fires, tornadoes, earthquakes, and terrorists, thereby exposing workers and the nearby public to potential adverse health effects. Various enforceable guidelines have been set by regulatory agencies for worker and ambient air quality. However, these exposure levels generally are not applicable to rare lifetime acute exposures, which possibly could occur at high concentrations. Acute exposure guideline levels (AEGLs) provide estimates of concentrations for airborne exposures for an array of short durations that possibly could cause mild (AEGL-1), severe, irreversible, potentially disabling adverse health effects (AEGL-2), or life threatening effects (AEGL-3). These levels can be useful for emergency responders and planners in reducing or eliminating potential risks to the public. Procedures and methodologies for deriving AEGLs are reviewed in this paper that have been developed in the United States, with direct input from international representatives of OECD member-countries, by the National Advisory Committee for Acute Exposure Guidelines for Hazardous Substances and reviewed by the National Research Council. Techniques are discussed for the extrapolation of effects across different exposure durations. AEGLs provide a viable approach for assisting in the prevention, planning, and response to acute airborne exposures to toxic agents.

Cognitive Effects of Air Pollution Exposures and Potential Mechanistic Underpinnings

PubMed Central

Allen, J.L.; Klocke, C.; Morris-Schaffer, K.; Conrad, K.; Sobolewski, M.; Cory-Slechta, D.A.

2017-01-01

Purpose of review This review sought to address the potential for air pollutants to impair cognition and mechanisms by which that might occur. Recent findings Air pollution has been associated with deficits in cognitive functions across a wide range of epidemiological studies, both with developmental and adult exposures. Studies in animal models are significantly more limited in number, with somewhat inconsistent findings to date for measures of learning, but show more consistent impairments for short term memory. Potential contributory mechanisms include oxidative stress/inflammation, altered levels of dopamine and/or glutamate and changes in synaptic plasticity/structure. Summary Epidemiological studies are consistent with adverse effects of air pollutants on cognition, but additional studies and better phenotypic characterization are needed for animal models, including more precise delineation of specific components of cognition that are affected, as well as definitions of critical exposure periods for such effects and the components of air pollution responsible. This would permit development of more circumscribed hypotheses as to potential behavioral and neurobiological mechanisms. PMID:28435996

Precocious glucocorticoid exposure reduces skeletal muscle satellite cells in the fetal rat

USDA-ARS?s Scientific Manuscript database

Perinatal skeletal muscle growth rates are a function of protein and myonuclear accretion. Precocious exposure of the fetus to glucocorticoids (GLC) in utero impairs muscle growth. Reduced muscle protein synthesis rates contribute to this response, but the consequences for myonuclear hyperplasia are...

Blueberry (Vaccinium ashei Reade) extract ameliorates ovarian damage induced by subchronic cadmium exposure in mice: Potential δ-ALA-D involvement.

PubMed

Izaguirry, Aryele Pinto; Soares, Melina Bucco; Vargas, Laura Musacchio; Spiazzi, Cristiano Chiapinotto; Dos Santos Brum, Daniela; Noremberg, Simone; Mendez, Andreas Sebastian Loureiro; Santos, Francielli Weber

2017-01-01

Females are born with a finite number of oocyte-containing follicles and ovary damage results in reduced fertility. Cadmium accumulates in the reproductive system, damaging it, and the cigarette smoke is a potential exposure route. Natural therapies are relevant to health benefits and disease prevention. This study verified the effect of cadmium exposure on the ovaries of mice and the blueberry extract as a potential therapy. Blueberry therapy was effective in restoring reactive species levels and δ-aminolevulinate dehydratase activity, and partially improved the viability of cadmium-disrupted follicles. This therapy was not able to restore the 17 β-hydroxysteroid dehydrogenase activity. Extract HPLC evaluation indicated the presence of quercetin, quercitrin, isoquercetin, and ascorbic acid. Ascorbic acid was the major substance and its concentration was 620.24 µg/mL. Thus, cadmium accumulates in the ovaries of mice after subchronic exposure, inducing cellular damage, and the blueberry extract possesses antioxidant properties that could protect, at least in part, the ovarian tissue from cadmium toxicity. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 188-196, 2017. © 2015 Wiley Periodicals, Inc.

Protons Offer Reduced Normal-Tissue Exposure for Patients Receiving Postoperative Radiotherapy for Resected Pancreatic Head Cancer

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

Nichols, Romaine C., E-mail: rnichols@floridaproton.org; Huh, Soon N.; Prado, Karl L.

2012-05-01

Purpose: To determine the potential role for adjuvant proton-based radiotherapy (PT) for resected pancreatic head cancer. Methods and Materials: Between June 2008 and November 2008, 8 consecutive patients with resected pancreatic head cancers underwent optimized intensity-modulated radiotherapy (IMRT) treatment planning. IMRT plans used between 10 and 18 fields and delivered 45 Gy to the initial planning target volume (PTV) and a 5.4 Gy boost to a reduced PTV. PTVs were defined according to the Radiation Therapy Oncology Group 9704 radiotherapy guidelines. Ninety-five percent of PTVs received 100% of the target dose and 100% of the PTVs received 95% of themore » target dose. Normal tissue constraints were as follows: right kidney V18 Gy to <70%; left kidney V18 Gy to <30%; small bowel/stomach V20 Gy to <50%, V45 Gy to <15%, V50 Gy to <10%, and V54 Gy to <5%; liver V30 Gy to <60%; and spinal cord maximum to 46 Gy. Optimized two- to three-field three-dimensional conformal proton plans were retrospectively generated on the same patients. The team generating the proton plans was blinded to the dose distributions achieved by the IMRT plans. The IMRT and proton plans were then compared. A Wilcoxon paired t-test was performed to compare various dosimetric points between the two plans for each patient. Results: All proton plans met all normal tissue constraints and were isoeffective with the corresponding IMRT plans in terms of PTV coverage. The proton plans offered significantly reduced normal-tissue exposure over the IMRT plans with respect to the following: median small bowel V20 Gy, 15.4% with protons versus 47.0% with IMRT (p = 0.0156); median gastric V20 Gy, 2.3% with protons versus 20.0% with IMRT (p = 0.0313); and median right kidney V18 Gy, 27.3% with protons versus 50.5% with IMRT (p = 0.0156). Conclusions: By reducing small bowel and stomach exposure, protons have the potential to reduce the acute and late toxicities of postoperative chemoradiation in this

Protons offer reduced normal-tissue exposure for patients receiving postoperative radiotherapy for resected pancreatic head cancer.

PubMed

Nichols, Romaine C; Huh, Soon N; Prado, Karl L; Yi, Byong Y; Sharma, Navesh K; Ho, Meng W; Hoppe, Bradford S; Mendenhall, Nancy P; Li, Zuofeng; Regine, William F

2012-05-01

To determine the potential role for adjuvant proton-based radiotherapy (PT) for resected pancreatic head cancer. Between June 2008 and November 2008, 8 consecutive patients with resected pancreatic head cancers underwent optimized intensity-modulated radiotherapy (IMRT) treatment planning. IMRT plans used between 10 and 18 fields and delivered 45 Gy to the initial planning target volume (PTV) and a 5.4 Gy boost to a reduced PTV. PTVs were defined according to the Radiation Therapy Oncology Group 9704 radiotherapy guidelines. Ninety-five percent of PTVs received 100% of the target dose and 100% of the PTVs received 95% of the target dose. Normal tissue constraints were as follows: right kidney V18 Gy to <70%; left kidney V18 Gy to <30%; small bowel/stomach V20 Gy to <50%, V45 Gy to <15%, V50 Gy to <10%, and V54 Gy to <5%; liver V30 Gy to <60%; and spinal cord maximum to 46 Gy. Optimized two- to three-field three-dimensional conformal proton plans were retrospectively generated on the same patients. The team generating the proton plans was blinded to the dose distributions achieved by the IMRT plans. The IMRT and proton plans were then compared. A Wilcoxon paired t-test was performed to compare various dosimetric points between the two plans for each patient. All proton plans met all normal tissue constraints and were isoeffective with the corresponding IMRT plans in terms of PTV coverage. The proton plans offered significantly reduced normal-tissue exposure over the IMRT plans with respect to the following: median small bowel V20 Gy, 15.4% with protons versus 47.0% with IMRT (p = 0.0156); median gastric V20 Gy, 2.3% with protons versus 20.0% with IMRT (p = 0.0313); and median right kidney V18 Gy, 27.3% with protons versus 50.5% with IMRT (p = 0.0156). By reducing small bowel and stomach exposure, protons have the potential to reduce the acute and late toxicities of postoperative chemoradiation in this setting. Copyright © 2012 Elsevier Inc. All rights reserved.

Chronic exposure to neonicotinoids reduces honey bee health near corn crops.

PubMed

Tsvetkov, N; Samson-Robert, O; Sood, K; Patel, H S; Malena, D A; Gajiwala, P H; Maciukiewicz, P; Fournier, V; Zayed, A

2017-06-30

Experiments linking neonicotinoids and declining bee health have been criticized for not simulating realistic exposure. Here we quantified the duration and magnitude of neonicotinoid exposure in Canada's corn-growing regions and used these data to design realistic experiments to investigate the effect of such insecticides on honey bees. Colonies near corn were naturally exposed to neonicotinoids for up to 4 months-the majority of the honey bee's active season. Realistic experiments showed that neonicotinoids increased worker mortality and were associated with declines in social immunity and increased queenlessness over time. We also discovered that the acute toxicity of neonicotinoids to honey bees doubles in the presence of a commonly encountered fungicide. Our work demonstrates that field-realistic exposure to neonicotinoids can reduce honey bee health in corn-growing regions. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Modifying welding process parameters can reduce the neurotoxic potential of manganese-containing welding fumes.

PubMed

Sriram, Krishnan; Lin, Gary X; Jefferson, Amy M; Stone, Samuel; Afshari, Aliakbar; Keane, Michael J; McKinney, Walter; Jackson, Mark; Chen, Bean T; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared L; Roberts, Jenny R; Frazer, David G; Antonini, James M

2015-02-03

Welding fumes (WF) are a complex mixture of toxic metals and gases, inhalation of which can lead to adverse health effects among welders. The presence of manganese (Mn) in welding electrodes is cause for concern about the potential development of Parkinson's disease (PD)-like neurological disorder. Consequently, from an occupational safety perspective, there is a critical need to prevent adverse exposures to WF. As the fume generation rate and physicochemical characteristics of welding aerosols are influenced by welding process parameters like voltage, current or shielding gas, we sought to determine if changing such parameters can alter the fume profile and consequently its neurotoxic potential. Specifically, we evaluated the influence of voltage on fume composition and neurotoxic outcome. Rats were exposed by whole-body inhalation (40 mg/m(3); 3h/day × 5 d/week × 2 weeks) to fumes generated by gas-metal arc welding using stainless steel electrodes (GMA-SS) at standard/regular voltage (25 V; RVSS) or high voltage (30 V; HVSS). Fumes generated under these conditions exhibited similar particulate morphology, appearing as chain-like aggregates; however, HVSS fumes comprised of a larger fraction of ultrafine particulates that are generally considered to be more toxic than their fine counterparts. Paradoxically, exposure to HVSS fumes did not elicit dopaminergic neurotoxicity, as monitored by the expression of dopaminergic and PD-related markers. We show that the lack of neurotoxicity is due to reduced solubility of Mn in HVSS fumes. Our findings show promise for process control procedures in developing prevention strategies for Mn-related neurotoxicity during welding; however, it warrants additional investigations to determine if such modifications can be suitably adapted at the workplace to avert or reduce adverse neurological risks. Published by Elsevier Ireland Ltd.

Modifying welding process parameters can reduce the neurotoxic potential of manganese-containing welding fumes

PubMed Central

Sriram, Krishnan; Lin, Gary X.; Jefferson, Amy M.; Stone, Samuel; Afshari, Aliakbar; Keane, Michael J.; McKinney, Walter; Jackson, Mark; Chen, Bean T.; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared L.; Roberts, Jenny R.; Frazer, David G.; Antonini, James M.

2015-01-01

Welding fumes (WF) are a complex mixture of toxic metals and gases, inhalation of which can lead to adverse health effects among welders. The presence of manganese (Mn) in welding electrodes is cause for concern about the potential development of Parkinson’s disease (PD)-like neurological disorder. Consequently, from an occupational safety perspective, there is a critical need to prevent adverse exposures to WF. As the fume generation rate and physicochemical characteristics of welding aerosols are influenced by welding process parameters like voltage, current or shielding gas, we sought to determine if changing such parameters can alter the fume profile and consequently its neurotoxic potential. Specifically, we evaluated the influence of voltage on fume composition and neurotoxic outcome. Rats were exposed by whole-body inhalation (40 mg/m3; 3 h/day × 5 d/week × 2 weeks) to fumes generated by gas–metal arc welding using stainless steel electrodes (GMA-SS) at standard/regular voltage (25 V; RVSS) or high voltage (30 V; HVSS). Fumes generated under these conditions exhibited similar particulate morphology, appearing as chain-like aggregates; however, HVSS fumes comprised of a larger fraction of ultrafine particulates that are generally considered to be more toxic than their ne counterparts. Paradoxically, exposure to HVSS fumes did not elicit dopaminergic neurotoxicity, as monitored by the expression of dopaminergic and PD-related markers. We show that the lack of neurotoxicity is due to reduced solubility of Mn in HVSS fumes. Our findings show promise for process control procedures in developing prevention strategies for Mn-related neurotoxicity during welding; however, it warrants additional investigations to determine if such modifications can be suitably adapted at the workplace to avert or reduce adverse neurological risks. PMID:25549921

Hazardous Chemicals on the Job: A Workers Guide to Reducing Exposure.

ERIC Educational Resources Information Center

Conrad, Fran; Kayman, Lindsey

This guide is intended to assist workers in reducing their exposure to hazardous chemicals on the job. It describes a systematic preventive approach to hazardous chemicals that is based on the following steps: determining which chemicals are in use at a particular worksite (techniques for asking the company and steps to take if the company is…

Relationship between Fosfomycin Exposure and Amplification of Escherichia coli Subpopulations with Reduced Susceptibility in a Hollow-Fiber Infection Model.

PubMed

VanScoy, Brian; McCauley, Jennifer; Bhavnani, Sujata M; Ellis-Grosse, Evelyn J; Ambrose, Paul G

2016-09-01

Understanding the relationship between antibiotic exposure and amplification of bacterial subpopulations with reduced drug susceptibility over time is important for evaluating the adequacy of dosing regimens. We utilized a hollow-fiber infection model to identify the fosfomycin intravenous dosing regimens that prevented the amplification of Escherichia coli bacterial subpopulations with reduced fosfomycin susceptibility. The challenge isolate was E. coli ATCC 25922 (agar MIC with glucose-6-phosphate, 1 mg/liter; agar MIC without glucose-6-phosphate, 32 mg/liter). The fosfomycin dosing regimens studied were 1 to 12 g every 8 h for 10 days to approximate that planned for clinical use. The studies included a no-treatment control regimen. Two bacterial subpopulations were identified, one with reduced susceptibility with agar MIC values ranging from 32 to 128 mg/liter and the other resistant with agar MIC values of 256 to >1,024 mg/liter on plates containing 5× and 256× the baseline MIC value, respectively. An inverted-U-shaped function best described the relationship between the amplification of the two bacterial subpopulations and drug exposure. The lowest fosfomycin dosing regimen that did not amplify a bacterial subpopulation with reduced susceptibility was 4 g administered every 8 h. Nearly immediate amplification of bacterial subpopulations with reduced susceptibility was observed with fosfomycin dosing regimens consisting of 1 to 2 g every 8 h. These data will be useful to support the selection of fosfomycin dosing regimens that minimize the potential for on-therapy amplification of bacterial subpopulations with reduced susceptibility. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Evaluation of the use of automatic exposure control and automatic tube potential selection in low-dose cerebrospinal fluid shunt head CT.

PubMed

Wallace, Adam N; Vyhmeister, Ross; Bagade, Swapnil; Chatterjee, Arindam; Hicks, Brandon; Ramirez-Giraldo, Juan Carlos; McKinstry, Robert C

2015-06-01

Cerebrospinal fluid shunts are primarily used for the treatment of hydrocephalus. Shunt complications may necessitate multiple non-contrast head CT scans resulting in potentially high levels of radiation dose starting at an early age. A new head CT protocol using automatic exposure control and automated tube potential selection has been implemented at our institution to reduce radiation exposure. The purpose of this study was to evaluate the reduction in radiation dose achieved by this protocol compared with a protocol with fixed parameters. A retrospective sample of 60 non-contrast head CT scans assessing for cerebrospinal fluid shunt malfunction was identified, 30 of which were performed with each protocol. The radiation doses of the two protocols were compared using the volume CT dose index and dose length product. The diagnostic acceptability and quality of each scan were evaluated by three independent readers. The new protocol lowered the average volume CT dose index from 15.2 to 9.2 mGy representing a 39 % reduction (P < 0.01; 95 % CI 35-44 %) and lowered the dose length product from 259.5 to 151.2 mGy/cm representing a 42 % reduction (P < 0.01; 95 % CI 34-50 %). The new protocol produced diagnostically acceptable scans with comparable image quality to the fixed parameter protocol. A pediatric shunt non-contrast head CT protocol using automatic exposure control and automated tube potential selection reduced patient radiation dose compared with a fixed parameter protocol while producing diagnostic images of comparable quality.

Comparison of human exposure pathways in an urban brownfield: reduced risk from paving roads.

PubMed

James, Kyle; Farrell, Richard E; Siciliano, Steven D

2012-10-01

Risk assessments often do not quantify the risk associated with soil inhalation. This pathway generally makes a negligible contribution to the cumulative risk, because soil ingestion is typically the dominant exposure pathway. Conditions in northern or rural centers in Canada characterized by large areas of exposed soil, including unpaved roads, favor the resuspension of soil particles, making soil inhalation a relevant risk pathway. The authors determined and compared human exposure to metals and polycyclic aromatic hydrocarbons (PAHs) from soil ingestion and inhalation and analyzed the carcinogenic and noncarcinogenic risks before and after roads were paved in a northern community. To determine the inhalation exposure, three size fractions of airborne particulate matter were collected (total suspended particulates [TSP], particulate matter with an aerodynamic diameter less than 10 µm [PM10], and particulate matter with an aerodynamic diameter less than 2.5 µm [PM2.5]) before and after roads were paved. Road paving reduced the concentration of many airborne contaminants by 25 to 75%, thus reducing risk. For example, before paving, the carcinogenic risk associated with inhalation of Cr was 3.4 excess cancers per 100,000 people exposed, whereas after paving, this risk was reduced to 1.6 in 100,000. Paving roads reduced the concentrations of total suspended particulates (TSP; p < 0.1) and PM10 (p < 0.05) but not PM25. Consequently, the ingestion of inhaled soil particles was substantially reduced. The authors conclude that resuspended soil is likely an important source of risk for many northern communities and that paving roads is an effective method of reducing risk from the inhalation of soil particles. Copyright © 2012 SETAC.

DEVELOPMENTAL LEAD (PB) EXPOSURE REDUCES THE ABILITY OF THE NNDA ANTAGONIST MK801 TO SUPPRESS LONG-TERM POTENTIATION (LTP) IN THE RAT DENTATE GYRUS, IN VIVO

EPA Science Inventory

Chronic developmental lead (Pb) exposure increases the threshold and enhances decay of long-term potentiation (LTP) in the dentate gyrus of the hippocampal formation. MK-801 and other antagonists of the N-methyl-D-aspartate (NMDA) glutamate receptor subtype impair induction of LT...

Perceptual individuation training (but not mere exposure) reduces implicit racial bias in preschool children.

PubMed

Qian, Miao K; Quinn, Paul C; Heyman, Gail D; Pascalis, Olivier; Fu, Genyue; Lee, Kang

2017-05-01

Two studies with preschool-age children examined the effectiveness of perceptual individuation training at reducing racial bias (Study 1, N = 32; Study 2, N = 56). We found that training preschool-age children to individuate other-race faces resulted in a reduction in implicit racial bias while mere exposure to other-race faces produced no such effect. We also showed that neither individuation training nor mere exposure reduced explicit racial bias. Theoretically, our findings provide strong evidence for a causal link between individual-level face processing and implicit racial bias, and are consistent with the newly proposed perceptual-social linkage hypothesis. Practically, our findings suggest that offering children experiences that allow them to increase their expertise in processing individual other-race faces will help reduce their implicit racial bias. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Engineering control technologies to reduce occupational silica exposures in masonry cutting and tuckpointing.

PubMed

Meeker, John D; Cooper, Michael R; Lefkowitz, Daniel; Susi, Pam

2009-01-01

A number of tasks in construction generate worker overexposures to respirable crystalline silica dust, which is a significant contributor to occupational mortality and morbidity. This study evaluated the performance of commercially available engineering controls used in dusty construction tasks commonly performed by bricklayers. Local exhaust ventilation (LEV) controls for a portable abrasive cutter and for tuckpointing grinders were examined at a bricklayers' training center, as were two stationary wet saws. Personal breathing zone air samples were collected with and without the use of LEV or water suppression during simulated concrete block cutting, brick cutting, and tuckpointing. Compared with the use of no exposure control during block and brick cutting, the portable LEV unit significantly reduced mean respirable quartz exposures by 96% for block cutting and 91% for brick cutting (p < 0.01). The use of stationary wet saws was also associated with 91% reductions in exposure (p < 0.01). For tuckpointing, the reductions in mean respirable quartz concentrations were between 91% and 93% with the LEV controls (p < 0.05). Reductions of up to 96% in mean respirable quartz concentration were observed between control and no-control scenarios. These reductions with commercially available off-the-shelf tools demonstrate the effectiveness of engineering control interventions to reduce crystalline silica exposures in construction. Strategies to further improve control performance and approaches for increasing control interventions in construction are needed.

Trichloroethylene Exposure Reduces Liver Injury in a Mouse Model of Primary Biliary Cholangitis.

PubMed

Ray, Jessica L; Kopec, Anna K; Joshi, Nikita; Cline-Fedewa, Holly; Lash, Lawrence H; Williams, Kurt J; Leung, Patrick S; Gershwin, M Eric; Luyendyk, James P

2017-04-01

Trichloroethylene (TCE) is a persistent environmental contaminant proposed to contribute to autoimmune disease. Experimental studies in lupus-prone MRL+/+ mice have suggested that TCE exposure can trigger autoimmune hepatitis. The vast majority of studies examining the connection between TCE and autoimmunity utilize this model, and the impact of TCE exposure in other established models of autoimmune liver disease is not known. We tested the hypothesis that TCE exposure exacerbates experimental hepatic autoimmunity in dominant negative transforming growth factor beta receptor type II (dnTGFBRII) mice, which develop serological and histological features resembling human primary biliary cholangitis. Female 8-week-old wild-type and dnTGFBRII mice were exposed to TCE (0.5 mg/ml) or vehicle (1% ethoxylated castor oil) in the drinking water for 12 or 22 weeks. Liver histopathology in 20- and 30-week-old wild-type mice was unremarkable irrespective of treatment. Mild portal inflammation was observed in vehicle-exposed 20-week-old dnTGFBRII mice and was not exacerbated by TCE exposure. Vehicle-exposed 30-week-old dnTGFBRII mice developed anti-mitochondrial antibodies, marked hepatic inflammation with necrosis, and hepatic accumulation of both B and T lymphocytes. To our surprise, TCE exposure dramatically reduced hepatic parenchymal inflammation and injury in 30-week-old dnTGFBRII mice, reflected by changes in hepatic proinflammatory gene expression, serum chemistry, and histopathology. Interestingly, TCE did not affect hepatic B cell accumulation or induction of the anti-inflammatory cytokine IL10. These data indicate that TCE exposure reduces autoimmune liver injury in female dnTGFBRII mice and suggests that the precise effect of environmental chemicals in autoimmunity depends on the experimental model. © 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.

Exposures of children to organophosphate pesticides and their potential adverse health effects.

PubMed Central

Eskenazi, B; Bradman, A; Castorina, R

1999-01-01

Recent studies show that young children can be exposed to pesticides during normal oral exploration of their environment and their level of dermal contact with floors and other surfaces. Children living in agricultural areas may be exposed to higher pesticide levels than other children because of pesticides tracked into their homes by household members, by pesticide drift, by breast milk from their farmworker mother, or by playing in nearby fields. Nevertheless, few studies have assessed the extent of children's pesticide exposure, and no studies have examined whether there are adverse health effects of chronic exposure. There is substantial toxicologic evidence that repeated low-level exposure to organophosphate (OP) pesticides may affect neurodevelopment and growth in developing animals. For example, animal studies have reported neurobehavorial effects such as impairment on maze performance, locomotion, and balance in neonates exposed (italic)in utero(/italic) and during early postnatal life. Possible mechanisms for these effects include inhibition of brain acetylcholinesterase, downregulation of muscarinic receptors, decreased brain DNA synthesis, and reduced brain weight in offspring. Research findings also suggest that it is biologically plausible that OP exposure may be related to respiratory disease in children through dysregulation of the autonomic nervous system. The University of California Berkeley Center for Children's Environmental Health Research is working to build a community-university partnership to study the environmental health of rural children. This Center for the Health Assessment of Mothers and Children of Salinas, or CHAMACOS in Monterey County, California, will assess (italic)in utero(/italic) and postnatal OP pesticide exposure and the relationship of exposure to neurodevelopment, growth, and symptoms of respiratory illness in children. The ultimate goal of the center is to translate research findings into a reduction of children

ASSESSING POTENTIAL EXPOSURES FROM ROUTINE USE OF VOC-CONTAMINATED GROUNDWATER

EPA Science Inventory

Three identical experiments were conducted in a single residence to assess potential exposures that may result from the routine household use of VOC-contaminated groundwater. Each experiment was based on a single 20-min shower using contaminated groundwater containing 185-367 ug/...

Potential health effects of indoor radon exposure.

PubMed Central

Radford, E P

1985-01-01

Radon-222 is a ubiquitous noble gas arising from decay of radium-226 normally present in the earth's crust. Alpha radiation from inhaled short-lived daughters of radon readily irradiates human bronchial epithelium, and there is now good evidence of excess risk of lung cancer in underground miners exposed to higher concentrations. In homes, radon levels are highly variable, showing approximately log-normal distributions and often a small fraction of homes with high concentrations of radon and radon daughters. Factors affecting indoor concentrations include type of bedrock under dwellings, house foundation characteristics, radon dissolved in artesian water, and ventilation and degree of air movement in living spaces. Despite much recent work, exposures to radon daughters by the general public are not well defined. From application of risk assessments in miners to home conditions, it appears that about 25% or more of lung cancers among nonsmokers over the age of 60, and about 5% in smokers, may be attributable to exposure to radon daughters at home. It may be necessary to take remedial action to reduce this hazard in those dwellings with elevated levels of radon, and new construction should take account of this problem. PMID:4085431

Prioritization of pesticides based on daily dietary exposure potential as determined from the SHEDS model.

PubMed

Melnyk, Lisa Jo; Wang, Zhaohui; Li, Zhilin; Xue, Jianping

2016-10-01

A major pathway for exposure to many pesticides is through diet. The objectives were to rank pesticides by comparing their calculated daily dietary exposure as determined by EPA's Stochastic Human Exposure and Dose Simulation (SHEDS) to single pesticides for different age groups to acceptable daily intakes (ADI), characterize pesticide trends in exposures over different time periods, and determine commodities contributing to pesticide exposures. SHEDS was applied, using Pesticide Data Program (PDP) (1991-2011) and pesticide usage data on crops from USDA combined with NHANES dietary consumption data, to generate exposure estimates by age group. ADI data collected from EPA, WHO, and other sources were used to rank pesticides based on relativeness of the dietary exposure potential to ADI by age groups. Sensitivity analysis provided trends in pesticide exposures. Within SHEDS, commodities contributing the majority of pesticides with greatest exposure potential were determined. The results indicated that the highest ranking pesticides were methamidophos and diazinon which exceeded 100% of the ADI. Sensitivity analysis indicated that exposure to methamidophos, diazinon, malathion, ethion and formetanate hydrochloride had a marked decrease from 1991-1999 to 2000-2011. Contributions analysis indicated that apples, mushroom, carrots, and lettuce contributed to diazinon exposure. Beans and pepper contributed to methamidophos exposure. Published by Elsevier Ltd.

Phenanthrene exposure induces cardiac hypertrophy via reducing miR-133a expression by DNA methylation

PubMed Central

Huang, Lixing; Xi, Zhihui; Wang, Chonggang; Zhang, Youyu; Yang, Zhibing; Zhang, Shiqi; Chen, Yixin; Zuo, Zhenghong

2016-01-01

Growing evidence indicates that there is an emerging link between environmental pollution and cardiac hypertrophy, while the mechanism is unclear. The objective of this study was to examine whether phenanthrene (Phe) could cause cardiac hypertrophy, and elucidate the molecular mechanisms involved. We found that: 1) Phe exposure increased the heart weight and cardiomyocyte size of rats; 2) Phe exposure led to enlarged cell size, and increased protein synthesis in H9C2 cells; 3) Phe exposure induced important markers of cardiac hypertrophy, such as atrial natriuretic peptide, B-type natriuretic peptide, and c-Myc in H9C2 cells and rat hearts; 4) Phe exposure perturbed miR-133a, CdC42 and RhoA, which were key regulators of cardiac hypertrophy, in H9C2 cells and rat hearts; 5) Phe exposure induced DNA methyltransferases (DNMTs) in H9C2 cells and rat hearts; 6) Phe exposure led to methylation of CpG sites within the miR-133a locus and reduced miR-133a expression in H9C2 cells; 7) DNMT inhibition and miR-133a overexpression could both alleviate the enlargement of cell size and perturbation of CdC42 and RhoA caused by Phe exposure. These results indicated that Phe could induce cardiomyocyte hypertrophy in the rat and H9C2 cells. The mechanism might involve reducing miR-133a expression by DNA methylation. PMID:26830171

Challenges in evaluating PM concentration levels, commuting exposure, and mask efficacy in reducing PM exposure in growing, urban communities in a developing country.

PubMed

Patel, Disa; Shibata, Tomoyuki; Wilson, James; Maidin, Alimin

2016-02-01

Particulate matter (PM) contributes to an increased risk of respiratory and cardiovascular illnesses, cancer, and preterm birth complications. This project assessed PM exposure in Eastern Indonesia's largest city, where air quality has not been comprehensively monitored. We examined the efficacy of wearing masks as an individual intervention effort to reduce in-transit PM exposures. Handheld particulate counters were used to investigate ambient air quality for spatial analysis, as well as the differences in exposure to PM2.5 and PM10 (μg/m(3)) by different transportation methods [e.g. motorcycle (n=97), pete-pete (n=53), and car (n=55); note: n=1 means 1m(3) of air sample]. Mask efficacy to reduce PM exposure was evaluated [e.g. surgical masks (n=39), bandanas (n=52), and motorcycle masks (n=39)]. A Monte Carlo simulation was used to provide a range of uncertainty in exposure assessment. Overall PM10 levels (91±124 μg/m(3)) were elevated compared to the World Health Organization (WHO)'s 24-hour air quality guideline (50 μg/m(3)). While average PM2.5 levels (9±14 μg/m(3)) were below the WHO's guideline (25 μg/m(3)), measurements up to 139 μg/m(3) were observed. Compared to cars, average motorcycle and pete-pete PM exposures were four and three times higher for PM2.5, and 13 and 10 times higher for PM10, respectively. Only surgical masks were consistent in lowering PM2.5 and PM10 (p<0.01). Young children (≤5) were the most vulnerable age group, and could not reach the safe dosage even when wearing surgical masks. Individual interventions can effectively reduce individual PM exposures; however, policy interventions will be needed to improve the overall air quality and create safer transportation. Copyright © 2015 Elsevier B.V. All rights reserved.

Modeling Exposures to the Oxidative Potential of PM10

PubMed Central

2012-01-01

Differences in the toxicity of ambient particulate matter (PM) due to varying particle composition across locations may contribute to variability in results from air pollution epidemiologic studies. Though most studies have used PM mass concentration as the exposure metric, an alternative which accounts for particle toxicity due to varying particle composition may better elucidate whether PM from specific sources is responsible for observed health effects. The oxidative potential (OP) of PM < 10 μm (PM10) was measured as the rate of depletion of the antioxidant reduced glutathione (GSH) in a model of human respiratory tract lining fluid. Using a database of GSH OP measures collected in greater London, U.K. from 2002 to 2006, we developed and validated a predictive spatiotemporal model of the weekly GSH OP of PM10 that included geographic predictors. Predicted levels of OP were then used in combination with those of weekly PM10 mass to estimate exposure to PM10 weighted by its OP. Using cross-validation (CV), brake and tire wear emissions of PM10 from traffic within 50 m and tailpipe emissions of nitrogen oxides from heavy-goods vehicles within 100 m were important predictors of GSH OP levels. Predictive accuracy of the models was high for PM10 (CV R2=0.83) but only moderate for GSH OP (CV R2 = 0.44) when comparing weekly levels; however, the GSH OP model predicted spatial trends well (spatial CV R2 = 0.73). Results suggest that PM10 emitted from traffic sources, specifically brake and tire wear, has a higher OP than that from other sources, and that this effect is very local, occurring within 50–100 m of roadways. PMID:22731499

Assessment of relative potential for Legionella species or surrogates inhalation exposure from common water uses.

PubMed

Hines, Stephanie A; Chappie, Daniel J; Lordo, Robert A; Miller, Brian D; Janke, Robert J; Lindquist, H Alan; Fox, Kim R; Ernst, Hiba S; Taft, Sarah C

2014-06-01

The Legionella species have been identified as important waterborne pathogens in terms of disease morbidity and mortality. Microbial exposure assessment is a tool that can be utilized to assess the potential of Legionella species inhalation exposure from common water uses. The screening-level exposure assessment presented in this paper developed emission factors to model aerosolization, quantitatively assessed inhalation exposures of aerosolized Legionella species or Legionella species surrogates while evaluating two generalized levels of assumed water concentrations, and developed a relative ranking of six common in-home uses of water for potential Legionella species inhalation exposure. Considerable variability in the calculated exposure dose was identified between the six identified exposure pathways, with the doses differing by over five orders of magnitude in each of the evaluated exposure scenarios. The assessment of exposure pathways that have been epidemiologically associated with legionellosis transmission (ultrasonic and cool mist humidifiers) produced higher estimated inhalation exposure doses than pathways where epidemiological evidence of transmission has been less strong (faucet and shower) or absent (toilets and therapy pool). With consideration of the large uncertainties inherent in the exposure assessment process used, a relative ranking of exposure pathways from highest to lowest exposure doses was produced using culture-based measurement data and the assumption of constant water concentration across exposure pathways. In this ranking, the ultrasonic and cool mist humidifier exposure pathways were estimated to produce the highest exposure doses, followed by the shower and faucet exposure pathways, and then the toilet and therapy pool exposure pathways. Published by Elsevier Ltd.

Reducing Children's Implicit Racial Bias through Exposure to Positive Out-Group Exemplars

ERIC Educational Resources Information Center

Gonzalez, Antonya M.; Steele, Jennifer R.; Baron, Andrew S.

2017-01-01

Studies with adults suggest that implicit preferences favoring White versus Black individuals can be reduced through exposure to positive Black exemplars. However, it remains unclear whether developmental differences exist in the capacity for these biases to be changed. This study included 369 children and examined whether their implicit racial…

An experimental model to measure the ability of headphones with active noise control to reduce patient's exposure to noise in an intensive care unit.

PubMed

Gallacher, Stuart; Enki, Doyo; Stevens, Sian; Bennett, Mark J

2017-10-17

Defining the association between excessive noise in intensive care units, sleep disturbance and morbidity, including delirium, is confounded by the difficulty of implementing successful strategies to reduce patient's exposure to noise. Active noise control devices may prove to be useful adjuncts but there is currently little to quantify their ability to reduce noise in this complex environment. Sound meters were embedded in the auditory meatus of three polystyrene model heads with no headphones (control), with headphones alone and with headphones using active noise control and placed in patient bays in a cardiac ICU. Ten days of recording sound levels at a frequency of 1 Hz were performed, and the noise levels in each group were compared using repeated measures MANOVA and subsequent pairwise testing. Multivariate testing demonstrated that there is a significant difference in the mean noise exposure levels between the three groups (p < 0.001). Subsequent pairwise testing between the three groups shows that the reduction in noise is greatest with headphones and active noise control. The mean reduction in noise exposure between the control and this group over 24 h is 6.8 (0.66) dB. The use of active noise control was also associated with a reduction in the exposure to high-intensity sound events over the course of the day. The use of active noise cancellation, as delivered by noise-cancelling headphones, is associated with a significant reduction in noise exposure in our model of noise exposure in a cardiac ICU. This is the first study to look at the potential effectiveness of active noise control in adult patients in an intensive care environment and shows that active noise control is a candidate technology to reduce noise exposure levels the patients experience during stays on intensive care.

Effects of prolonged exposure and virtual reality exposure on suicidal ideation in active duty soldiers: An examination of potential mechanisms.

PubMed

Norr, Aaron M; Smolenski, Derek J; Reger, Greg M

2018-05-12

The current study sought to investigate the effects of exposure therapy on suicidal ideation (SI), as well as potential mechanistic pathways of SI reduction among active duty military personnel. Active duty army soldiers (N = 162) were recruited from a military base in the U.S. and were enrolled in a randomized clinical trial comparing Prolonged Exposure (PE), Virtual Reality Exposure (VRE), and a wait-list control for the treatment of posttraumatic stress disorder (PTSD) stemming from deployments to Iraq or Afghanistan. PTSD diagnosis followed DSM-IV-TR criteria. Outcome measures were assessed via self-report and clinician interview. PTSD symptoms, depressive symptoms, and SI were included in an autoregressive cross-lagged panel model to examine mechanistic pathways. Analyses revealed that PE/VRE had a lower probability of post-treatment suicidal ideation (OR = 0.23, 95% CI [0.06, 0.86]) compared to the waitlist control. Mediation analyses revealed a significant indirect effect from treatment condition to post-treatment PTSD symptoms through mid-treatment SI (Estimate = -1.420, 95% CI -3.559, -0.223]). Baseline suicidal ideation did not interact with treatment condition to predict PTSD symptom change at mid-treatment (p = .231) or post-treatment (p = .672). PE/VRE successfully reduced SI, and the presence of SI at baseline did not affect PTSD symptom reduction, promoting the utility of using PE/VRE to address suicidality among individuals with PTSD. Mediation analyses suggest that reductions in SI were achieved early in treatment. Published by Elsevier Ltd.

Improving performance of HVAC systems to reduce exposure to aerosolized infectious agents in buildings; recommendations to reduce risks posed by biological attacks.

PubMed

Hitchcock, Penny J; Mair, Michael; Inglesby, Thomas V; Gross, Jonathan; Henderson, D A; O'Toole, Tara; Ahern-Seronde, Joa; Bahnfleth, William P; Brennan, Terry; Burroughs, H E Barney; Davidson, Cliff; Delp, William; Ensor, David S; Gomory, Ralph; Olsiewski, Paula; Samet, Jonathan M; Smith, William M; Streifel, Andrew J; White, Ronald H; Woods, James E

2006-01-01

The prospect of biological attacks is a growing strategic threat. Covert aerosol attacks inside a building are of particular concern. In the summer of 2005, the Center for Biosecurity of the University of Pittsburgh Medical Center convened a Working Group to determine what steps could be taken to reduce the risk of exposure of building occupants after an aerosol release of a biological weapon. The Working Group was composed of subject matter experts in air filtration, building ventilation and pressurization, air conditioning and air distribution, biosecurity, building design and operation, building decontamination and restoration, economics, medicine, public health, and public policy. The group focused on functions of the heating, ventilation, and air conditioning systems in commercial or public buildings that could reduce the risk of exposure to deleterious aerosols following biological attacks. The Working Group's recommendations for building owners are based on the use of currently available, off-the-shelf technologies. These recommendations are modest in expense and could be implemented immediately. It is also the Working Group's judgment that the commitment and stewardship of a lead government agency is essential to secure the necessary financial and human resources and to plan and build a comprehensive, effective program to reduce exposure to aerosolized infectious agents in buildings.

Assessment of potential exposure to friable insulation materials containing asbestos

NASA Technical Reports Server (NTRS)

Kim, W. S.; Kuivinen, D. E.

1980-01-01

Asbestos and the procedures for assessing potential exposure hazards are discussed. Assessment includes testing a bulk sample of the suspected material for the presence of asbestos, and monitoring the air, if necessary. Based on field inspections and laboratory analyses, the health hazard is evaluated, and abatement measures are taken if a potential hazard exists. Throughout the assessment and abatement program, all applicable regulations are administered as specified by the Environmental Protection Agency and the Occupational Safety and Health Administration.

The impact of smoke-free legislation on reducing exposure to secondhand smoke: differences across gender and socioeconomic groups.

PubMed

Tsai, Yi-Wen; Chang, Li-Chuan; Sung, Hai-Yen; Hu, Teh-Wei; Chiou, Shu-Ti

2015-01-01

On 11 January 2009, Taiwan expanded its smoke-free legislation to all indoor public places and workplaces. This study examined the impact of this policy on secondhand smoke (SHS) exposure in adult non-smokers, across gender and socioeconomic status groups (SES). An annual sample of about 13,000-14,000 non-smokers was drawn from cross-sectional nationwide data of Taiwan Adult Tobacco Behavior Surveys during 2005-2011. Logistic regressions were used to analyse the aggregate data to estimate the association between the 2009 smoke-free legislation and SHS exposures in homes and workplaces. Interaction terms were used to examine the impact of the 2009 smoke-free policy on reducing differences in SHS exposure across gender, education and income groups. The 2009 policy reduced the odds of SHS exposure in homes in 2009 (OR=0.76, 95% CI 0.68 to 0.84) and in workplaces (year 2009: OR=0.49, 95% CI 0.39 to 0.62; year 2010: OR=0.79, 95% CI 0.66 to 0.95). The model with interaction terms showed that men were more likely than women to be exposed to workplace SHS (OR=2.02, 95% CI 1.80 to 2.27) but were less likely to be exposed to home SHS (OR=0.79, 95% CI 0.73 to 0.86). SHS exposure in homes was significantly related to lower socioeconomic status, but the 2009 smoke-free policy reduced the difference in SHS exposure across education levels. The 2009 smoke-free policy reduced the SHS exposure for non-smokers. However, this impact on home SHS did not persist after 2009, and the effect of protection was unequal across gender and SES groups. Thus, further enforcement of smoking restrictions would be needed to reduce the risk of SHS exposure and improve protection against SHS risk among parts of the population with lower socioeconomic status. 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.

Potential Dermal Exposure to Flonicamid and Risk Assessment of Applicators During Treatment in Apple Orchards.

PubMed

Zhao, Mei-Ai; Yu, Aili; Zhu, Yong-Zhe; Kim, Jeong-Han

2015-01-01

Exposure and risk assessments of flonicamid for applicators were performed in apple orchards in Korea. Fifteen experiments were done with two experienced applicators under typical field conditions using a speed sprayer. In this study, cotton gloves, socks, masks, and dermal patches were used to monitor potential dermal exposure to flonicamid, and personal air samplers with XAD-2 resin and glass fiber filter were used to monitor potential inhalation exposure. The analytical methods were validated for the limit of detection, limit of quantitation, reproducibility, linearity of the calibration curve, and recovery of flonicamid from various exposure matrices. The results were encouraging and acceptable for an exposure study. The applicability of XAD-2 resin was evaluated via a trapping efficiency and breakthrough test. During the mixing/loading, the average total dermal exposure was 22.6 μg of flonicamid, corresponding to 4.5×10(-5)% of the prepared amount. For the spraying, the potential dermal exposure was 9.32 mg, and the ratio to applied amount was 1.9 × 10(-2%). The primary exposed body parts were the thigh (2.90 mg), upper arm (1.75 mg), and lower leg (1.66 mg). By comparison, absorbable quantity of exposure was small, only 1.62 μg (3.2×10(-6)%). The margin of safety (MOS) were calculated for risk assessment, in all sets of trials, MOS > 1, indicating the exposure level of flonicamid was considered to be safe in apple orchards. Although this was a limited study, it provided a good estimate of flonicamid exposure for orchard applicators.

Spectrum pattern resolution after noise exposure in a beluga whale, Delphinapterus leucas: Evoked potential study.

PubMed

Popov, Vladimir V; Nechaev, Dmitry I; Sysueva, Evgenia V; Rozhnov, Viatcheslav V; Supin, Alexander Ya

2015-07-01

Temporary threshold shift (TTS) and the discrimination of spectrum patterns after fatiguing noise exposure (170 dB re 1 μPa, 10 min duration) was investigated in a beluga whale, Delphinapterus leucas, using the evoked potential technique. Thresholds were measured using rhythmic (1000/s) pip trains of varying levels and recording the rhythmic evoked responses. Discrimination of spectrum patterns was investigated using rippled-spectrum test stimuli of various levels and ripple densities, recording the rhythmic evoked responses to ripple phase reversals. Before noise exposure, the greatest responses to rippled-spectrum probes were evoked by stimuli with a low ripple density with a decrease in the response magnitude occurring with an increasing ripple density. After noise exposure, both a TTS and a reduction of the responses to rippled-spectrum probes appeared and recovered in parallel. The reduction of the responses to rippled-spectrum probes was maximal for high-magnitude responses at low ripple densities and was negligible for low-magnitude responses at high ripple densities. It is hypothesized that the impacts of fatiguing sounds are not limited by increased thresholds and decreased sensitivity results in reduced ability to discriminate fine spectral content with the greatest impact on the discrimination of spectrum content that may carry the most obvious information about stimulus properties.

Pankiller effect of prolonged exposure to menadione on glioma cells: potentiation by vitamin C.

PubMed

Vita, Marina F; Nagachar, Nivedita; Avramidis, Dimitrios; Delwar, Zahid M; Cruz, Mabel H; Siden, Åke; Paulsson, Kajsa M; Yakisich, Juan Sebastian

2011-12-01

Menadione (Vitamin K3) has anti-tumoral effects against a wide range of cancer cells. Its potential toxicity to normal cells and narrow therapeutic range limit its use as single agent but in combination with radiation or other anti-neoplastic agents can be of therapeutic use. In this paper, we first evaluated the early (within 3 h) effect of menadione on ongoing DNA replication. In normal rat cerebral cortex mini-units menadione showed an age dependent anti-proliferative effect. In tissue mini-units prepared from newborn rats, menadione inhibited ongoing DNA replication with an IC (50) of approximately 10 μM but 50 μM had no effect on mini-units from prepared adult rat tissue. The effect of short (72 h) and prolonged exposure (1-2 weeks) to menadione alone in the DBTRG.05MG human glioma cells line and in combination with vitamin C was studied. After short period of exposure data show that menadione alone or in combination with vitamin C provided similar concentration-response curves (and IC(50) values). Prolonged exposure to these drugs was evaluated by their ability to kill 100% of glioma cells and prevent regrowth when cells are re-incubated in drug-free media. In this long-term assay, menadione:vitamin C at a ratio 1:100 showed higher anti-proliferative activity when compared to each drug alone and allowed to reduce each drug concentration between 2.5 to 5-fold. Similar anti-proliferative effect was demonstrated in 8 patient derived glioblastoma cell cultures. Our data should be able to encourage further advanced studies on animal models to evaluate the potential use of this combination therapy for glioma treatment.

Intrauterine Exposure to Paracetamol and Aniline Impairs Female Reproductive Development by Reducing Follicle Reserves and Fertility.

PubMed

Holm, Jacob Bak; Mazaud-Guittot, Severine; Danneskiold-Samsøe, Niels Banhos; Chalmey, Clementine; Jensen, Benjamin; Nørregård, Mette Marie; Hansen, Cecilie Hurup; Styrishave, Bjarne; Svingen, Terje; Vinggaard, Anne Marie; Koch, Holger Martin; Bowles, Josephine; Koopman, Peter; Jégou, Bernard; Kristiansen, Karsten; Kristensen, David Møbjerg

2016-03-01

Studies report that fetal exposure to paracetamol/acetaminophen by maternal consumption can interfere with male reproductive development. Moreover, recent biomonitoring data report widespread presence of paracetamol in German and Danish populations, suggesting exposure via secondary (nonpharmaceutical) sources, such as metabolic conversion from the ubiquitous industrial compound aniline. In this study, we investigated the extent to which paracetamol and aniline can interfere with female reproductive development. Intrauterine exposure to paracetamol by gavage of pregnant dams resulted in shortening of the anogenital distance in adult offspring, suggesting that fetal hormone signaling had been disturbed. Female offspring of paracetamol-exposed mothers had ovaries with diminished follicle reserve and reduced fertility. Fetal gonads of exposed animals had also reduced gonocyte numbers, suggesting that the reduced follicle count in adults could be due to early disruption of germ cell development. However, ex vivo cultures of ovaries from 12.5 days post coitum fetuses showed no decrease in proliferation or expression following exposure to paracetamol. This suggests that the effect of paracetamol occurs prior to this developmental stage. Accordingly, using embryonic stem cells as a proxy for primordial germ cells we show that paracetamol is an inhibitor of cellular proliferation, but without cytotoxic effects. Collectively, our data show that intrauterine exposure to paracetamol at levels commonly observed in pregnant women, as well as its precursor aniline, may block primordial germ cell proliferation, ultimately leading to reduced follicle reserves and compromised reproductive capacity later in life. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Evaluation of commercially available seat suspensions to reduce whole body vibration exposures in mining heavy equipment vehicle operators.

PubMed

Kim, Jeong Ho; Marin, Luz S; Dennerlein, Jack T

2018-09-01

As mining vehicle operators are exposed to high level of Whole body vibration (WBV) for prolonged periods of time, approaches to reduce this exposure are needed for the specific types of exposures in mining. Although various engineering controls (i.e. seat suspension systems) have been developed to address WBV, there has been lack of research to systematically evaluate these systems in reducing WBV exposures in mining heavy equipment vehicle settings. Therefore, this laboratory-based study evaluated the efficacy of different combinations of fore-aft (x-axis), lateral (y-axis), and vertical (z-axis) suspensions in reducing WBV exposures. The results showed that the active vertical suspension more effectively reduced the vertical vibration (∼50%; p's < 0.0001) as compared to the passive vertical suspension (10%; p's < 0.11). The passive fore-aft (x-axis) and lateral (y-axis) suspension systems did not attenuate the corresponding axis vibration (p's > 0.06) and sometimes amplified the floor vibration, especially when the non-vertical vibration was predominant (p's < 0.02). These results indicate that there is a critical need to develop more effective engineering controls including better seat suspensions to address non-vertical WBV exposures, especially because these non-vertical WBV exposures can increase risks for adverse health effects including musculoskeletal loading, discomfort, and impaired visual acuity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characteristics of current and recent former smokers associated with the use of new potential reduced-exposure tobacco products.

PubMed

Parascandola, Mark; Augustson, Erik; Rose, Allison

2009-12-01

To identify sociodemographic characteristics associated with having tried a potentialy reduced-exposure tobacco product (PREP) and to compare the smoking and quitting behaviors and attitudes of smokers who have tried a PREP product with non-PREP users. Analysis is based on a sample of 43,419 current and recent former smokers from the 2003 Tobacco Use Supplement to the Current Population Survey. Overall, PREP use is low (2.5%). Current daily and someday only smokers have higher rates of use (2.9% and 2.4%, respectively) compared with former smokers (1.5%). PREP use is higher in southern states and among younger smokers, non-Hispanic Whites, and those with some college education. Smokers who have tried a PREP product are more likely to smoke light or ultra-light cigarettes, report more symptoms of nicotine dependence, smoke more cigarettes per day, report a higher number of quit attempts, and seek quitting assistance from pharmacotherapy and behavioral therapies compared with non-PREP users. These findings support the concern that current smokers who are highly dependent yet motivated to quit smoking may seek PREPs as an alternative strategy to smoking cessation.

Exposure to Potentially Traumatic Events in Early Childhood: Differential Links to Emergent Psychopathology

ERIC Educational Resources Information Center

Briggs-Gowan, Margaret J.; Carter, Alice S.; Clark, Roseanne; Augustyn, Marilyn; McCarthy, Kimberly J.; Ford, Julian D.

2010-01-01

Research NeedsObjective: To examine associations between exposure to potentially traumatic events (PTEs) and clinical patterns of symptoms and disorders in preschool children. Method: Two hundred and thirteen referred and non-referred children, ages 24 to 48 months (MN = 34.9, SD = 6.7 months) were studied. Lifetime exposure to PTEs (family…

Urinary microRNAs as potential biomarkers of pesticide exposure

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

Weldon, Brittany A.; Shubin, Sara Pacheco; Smith,

MicroRNAs (miRNAs) are post-transcriptional regulators that silence messenger RNAs. Because miRNAs are stable at room temperature and long-lived, they have been proposed as molecular biomarkers to monitor disease and exposure status. While urinary miRNAs have been used clinically as potential diagnostic markers for kidney and bladder cancers and other diseases, their utility in non-clinical settings has yet to be fully developed. Our goal was to investigate the potential for urinary miRNAs to act as biomarkers of pesticide exposure and early biological response by identifying the miRNAs present in urine from 27 parent/child, farmworker/non-farmworker pairs (16FW/11NFW) collected during two agricultural seasonsmore » (thinning and post-harvest) and characterizing the between- and within-individual variability of these miRNA epigenetic regulators. MiRNAs were isolated from archived urine samples and identified using PCR arrays. Comparisons were made between age, households, season, and occupation. Of 384 miRNAs investigated, 297 (77%) were detectable in at least one sample. Seven miRNAs were detected in at least 50% of the samples, and one miRNA was present in 96% of the samples. Principal components and hierarchical clustering analyses indicate significant differences in miRNA profiles between farmworker and non-farmworker adults as well as between seasons. Six miRNAs were observed to be positively associated with farmworkers status during the post-harvest season. Expression of five of these miRNA trended towards a positive dose response relationship with organophosphate pesticide metabolites in farmworkers. These results suggest that miRNAs may be novel biomarkers of pesticide exposure and early biological response. - Highlights: • A novel method to identify microRNA biomarkers in urinary samples is proposed. • Six miRNAs have been identified as associated with occupational farm work and pesticide exposure. • An observed seasonal difference suggests

Brainstem auditory evoked potentials in children with lead exposure.

PubMed

Alvarenga, Katia de Freitas; Morata, Thais Catalani; Lopes, Andrea Cintra; Feniman, Mariza Ribeiro; Corteletti, Lilian Cassia Bornia Jacob

2015-01-01

Earlier studies have demonstrated an auditory effect of lead exposure in children, but information on the effects of low chronic exposures needs to be further elucidated. To investigate the effect of low chronic exposures of the auditory system in children with a history of low blood lead levels, using an auditory electrophysiological test. Contemporary cross-sectional cohort. Study participants underwent tympanometry, pure tone and speech audiometry, transient evoked otoacoustic emissions, and brainstem auditory evoked potentials, with blood lead monitoring over a period of 35.5 months. The study included 130 children, with ages ranging from 18 months to 14 years, 5 months (mean age 6 years, 8 months ± 3 years, 2 months). The mean time-integrated cumulative blood lead index was 12 μg/dL (SD ± 5.7, range: 2.433). All participants had hearing thresholds equal to or below 20 dBHL and normal amplitudes of transient evoked otoacoustic emissions. No association was found between the absolute latencies of waves I, III, and V, the interpeak latencies I-III, III-V, and I-V, and the cumulative lead values. No evidence of toxic effects from chronic low lead exposures was observed on the auditory function of children living in a lead contaminated area. Copyright © 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Prenatal exposure to restraint or predator stresses attenuates field excitatory postsynaptic potentials in infant rats.

PubMed

Saboory, Ehsan; Ahmadzadeh, Ramin; Roshan-Milani, Shiva

2011-12-01

Exposure to stress is known to change synaptic plasticity and results in long-term depression; further, this stress precipitates seizures. In the study described here, the prenatal restraint and predator stress models were used to test the hypothesis that indirect prenatal stresses influence hippocampal synaptic potentiation and may affect seizures susceptibility in infant rats. Pregnant female Wistar rats were divided into 3 groups: control, restraint-stressed, and predator-stressed groups. Both stressed groups were exposed to the stressor on gestation days 15, 16, and 17. The restraint stress involved 1-h sessions twice daily in a Plexiglas tube and the predator stress involved 2-h sessions once daily in a cage placed within the visual range of a caged cat. Blood corticosterone (COS) levels were measured in different time points. Hippocampal slices were prepared and field excitatory postsynaptic potentials (fEPSP) were studied on postnatal day 15. Pilocarpine was administered on postnatal day 25 and mortality rates were measured after 2 and 24h. Restraint and predator stresses resulted in significantly elevated COS blood levels in dams and pups. Both the amplitude and slope of fEPSP in the CA1 area decreased significantly in the stressed groups as compared to the control. Prenatal restraint and predator stresses significantly increased the fatal effect of pilocarpine at 24h after injection. Exposure to prenatal stresses and COS blood levels elevation reduce hippocampal synaptic potentiation and increase mortality rate of seizure in infant rats and may affect on later seizure susceptibility and prognosis. Copyright © 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

Understanding Potential Exposure Sources of Perfluorinated Carboxylic Acids in the Workplace

PubMed Central

Kaiser, Mary A.; Dawson, Barbara J.; Barton, Catherine A.; Botelho, Miguel A.

2010-01-01

This paper integrates perspectives from analytical chemistry, environmental engineering, and industrial hygiene to better understand how workers may be exposed to perfluorinated carboxylic acids when handling them in the workplace in order to identify appropriate exposure controls. Due to the dramatic difference in physical properties of the protonated acid form and the anionic form, this family of chemicals provides unique industrial hygiene challenges. Workplace monitoring, experimental data, and modeling results were used to ascertain the most probable workplace exposure sources and transport mechanisms for perfluorooctanoic acid (PFOA) and its ammonium salt (APFO). PFOA is biopersistent and its measurement in the blood has been used to assess human exposure since it integrates exposure from all routes of entry. Monitoring suggests that inhalation of airborne material may be an important exposure route. Transport studies indicated that, under low pH conditions, PFOA, the undissociated (acid) species, actively partitions from water into air. In addition, solid-phase PFOA and APFO may also sublime into the air. Modeling studies determined that contributions from surface sublimation and loss from low pH aqueous solutions can be significant potential sources of workplace exposure. These findings suggest that keeping surfaces clean, preventing accumulation of material in unventilated areas, removing solids from waste trenches and sumps, and maintaining neutral pH in sumps can lower workplace exposures. PMID:20974675

Understanding potential exposure sources of perfluorinated carboxylic acids in the workplace.

PubMed

Kaiser, Mary A; Dawson, Barbara J; Barton, Catherine A; Botelho, Miguel A

2010-11-01

This paper integrates perspectives from analytical chemistry, environmental engineering, and industrial hygiene to better understand how workers may be exposed to perfluorinated carboxylic acids when handling them in the workplace in order to identify appropriate exposure controls. Due to the dramatic difference in physical properties of the protonated acid form and the anionic form, this family of chemicals provides unique industrial hygiene challenges. Workplace monitoring, experimental data, and modeling results were used to ascertain the most probable workplace exposure sources and transport mechanisms for perfluorooctanoic acid (PFOA) and its ammonium salt (APFO). PFOA is biopersistent and its measurement in the blood has been used to assess human exposure since it integrates exposure from all routes of entry. Monitoring suggests that inhalation of airborne material may be an important exposure route. Transport studies indicated that, under low pH conditions, PFOA, the undissociated (acid) species, actively partitions from water into air. In addition, solid-phase PFOA and APFO may also sublime into the air. Modeling studies determined that contributions from surface sublimation and loss from low pH aqueous solutions can be significant potential sources of workplace exposure. These findings suggest that keeping surfaces clean, preventing accumulation of material in unventilated areas, removing solids from waste trenches and sumps, and maintaining neutral pH in sumps can lower workplace exposures.

What can individuals do to reduce personal health risks from air pollution?

PubMed Central

Laumbach, Robert; Meng, Qingyu

2015-01-01

In many areas of the world, concentrations of ambient air pollutants exceed levels associated with increased risk of acute and chronic health problems. While effective policies to reduce emissions at their sources are clearly preferable, some evidence supports the effectiveness of individual actions to reduce exposure and health risks. Personal exposure to ambient air pollution can be reduced on high air pollution days by staying indoors, reducing outdoor air infiltration to indoors, cleaning indoor air with air filters, and limiting physical exertion, especially outdoors and near air pollution sources. Limited evidence suggests that the use of respirators may be effective in some circumstances. Awareness of air pollution levels is facilitated by a growing number of public air quality alert systems. Avoiding exposure to air pollutants is especially important for susceptible individuals with chronic cardiovascular or pulmonary disease, children, and the elderly. Research on mechanisms underlying the adverse health effects of air pollution have suggested potential pharmaceutical or chemopreventive interventions, such as antioxidant or antithrombotic agents, but in the absence of data on health outcomes, no sound recommendations can be made for primary prevention. Health care providers and their patients should carefully consider individual circumstances related to outdoor and indoor air pollutant exposure levels and susceptibility to those air pollutants when deciding on a course of action to reduce personal exposure and health risks from ambient air pollutants. Careful consideration is especially warranted when interventions may have unintended negative consequences, such as when efforts to avoid exposure to air pollutants lead to reduced physical activity or when there is evidence that dietary supplements, such as antioxidants, have potential adverse health effects. These potential complications of partially effective personal interventions to reduce exposure or

What can individuals do to reduce personal health risks from air pollution?

PubMed

Laumbach, Robert; Meng, Qingyu; Kipen, Howard

2015-01-01

In many areas of the world, concentrations of ambient air pollutants exceed levels associated with increased risk of acute and chronic health problems. While effective policies to reduce emissions at their sources are clearly preferable, some evidence supports the effectiveness of individual actions to reduce exposure and health risks. Personal exposure to ambient air pollution can be reduced on high air pollution days by staying indoors, reducing outdoor air infiltration to indoors, cleaning indoor air with air filters, and limiting physical exertion, especially outdoors and near air pollution sources. Limited evidence suggests that the use of respirators may be effective in some circumstances. Awareness of air pollution levels is facilitated by a growing number of public air quality alert systems. Avoiding exposure to air pollutants is especially important for susceptible individuals with chronic cardiovascular or pulmonary disease, children, and the elderly. Research on mechanisms underlying the adverse health effects of air pollution have suggested potential pharmaceutical or chemopreventive interventions, such as antioxidant or antithrombotic agents, but in the absence of data on health outcomes, no sound recommendations can be made for primary prevention. Health care providers and their patients should carefully consider individual circumstances related to outdoor and indoor air pollutant exposure levels and susceptibility to those air pollutants when deciding on a course of action to reduce personal exposure and health risks from ambient air pollutants. Careful consideration is especially warranted when interventions may have unintended negative consequences, such as when efforts to avoid exposure to air pollutants lead to reduced physical activity or when there is evidence that dietary supplements, such as antioxidants, have potential adverse health effects. These potential complications of partially effective personal interventions to reduce exposure or

Prevalence and public health implications of state laws that criminalize potential HIV exposure in the United States.

PubMed

Lehman, J Stan; Carr, Meredith H; Nichol, Allison J; Ruisanchez, Alberto; Knight, David W; Langford, Anne E; Gray, Simone C; Mermin, Jonathan H

2014-06-01

For the past three decades, legislative approaches to prevent HIV transmission have been used at the national, state, and local levels. One punitive legislative approach has been enactment of laws that criminalize behaviors associated with HIV exposure (HIV-specific criminal laws). In the USA, HIV-specific criminal laws have largely been shaped by state laws. These laws impose criminal penalties on persons who know they have HIV and subsequently engage in certain behaviors, most commonly sexual activity without prior disclosure of HIV-positive serostatus. These laws have been subject to intense public debate. Using public health law research methods, data from the legal database WestlawNext© were analyzed to describe the prevalence and characteristics of laws that criminalize potential HIV exposure in the 50 states (plus the District of Columbia) and to examine the implications of these laws for public health practice. The first state laws were enacted in 1986; as of 2011 a total of 67 laws had been enacted in 33 states. By 1995, nearly two-thirds of all laws had been enacted; by 2000, 85 % of laws had been enacted; and since 2000, an additional 10 laws have been enacted. Twenty-four states require persons who are aware that they have HIV to disclose their status to sexual partners and 14 states require disclosure to needle-sharing partners. Twenty-five states criminalize one or more behaviors that pose a low or negligible risk for HIV transmission. Nearly two-thirds of states in the USA have legislation that criminalizes potential HIV exposure. Many of these laws criminalize behaviors that pose low or negligible risk for HIV transmission. The majority of laws were passed before studies showed that antiretroviral therapy (ART) reduces HIV transmission risk and most laws do not account for HIV prevention measures that reduce transmission risk, such as condom use, ART, or pre-exposure prophylaxis. States with HIV-specific criminal laws are encouraged to use the

Use of prescribed fire to reduce wildfire potential

Treesearch

Robert E. Martin; J. Boone Kauffman

1989-01-01

Fires were a part of our wildlands prehistorically. Prescribed burning reduces fire hazard and potential fire behavior primarily by reducing fuel quantity and continuity. Fuel continuity should be considered on the micro scale within stands, the mid-scale among, and the macro-scale among watersheds or entire forests. Prescribed fire is only one of the tools which can...

Reducing Exposure to High Fluoride Drinking Water in Estonia—A Countrywide Study

PubMed Central

Indermitte, Ene; Saava, Astrid; Karro, Enn

2014-01-01

Fluoride is a naturally occurring contaminant in groundwater in Estonia. There are several regions in Estonia with fluoride contents in public water supplies as high as 7 mg/L. Long-term exposure to high-fluoride drinking water may have several adverse health effects, primarily dental fluorosis. The opportunities for exposure reduction rely highly on water treatment technologies. Since 2004 public water suppliers in Estonia have made efforts to diminish fluoride content in drinking water systems. A follow-up study on a country level was carried out in 2004–2012 to analyze the changes in population exposure to excessive (over 1.5 mg/L) fluoride in drinking water and to get information about the reduction methods applied by public water supplies (PWS) to optimize the fluoride levels in public water system. The results showed that bigger PWS have been more effective in fluoride reduction measures than small PWS. The main methods used to lower the fluoride content were reverse osmosis technology and replacement of water sources with new ones (new drilled wells). As a result of all the measures taken the overall high-fluoride exposure has been reduced substantially (82%). PMID:24637908

Reducing exposure to high fluoride drinking water in Estonia-a countrywide study.

PubMed

Indermitte, Ene; Saava, Astrid; Karro, Enn

2014-03-14

Fluoride is a naturally occurring contaminant in groundwater in Estonia. There are several regions in Estonia with fluoride contents in public water supplies as high as 7 mg/L. Long-term exposure to high-fluoride drinking water may have several adverse health effects, primarily dental fluorosis. The opportunities for exposure reduction rely highly on water treatment technologies. Since 2004 public water suppliers in Estonia have made efforts to diminish fluoride content in drinking water systems. A follow-up study on a country level was carried out in 2004-2012 to analyze the changes in population exposure to excessive (over 1.5 mg/L) fluoride in drinking water and to get information about the reduction methods applied by public water supplies (PWS) to optimize the fluoride levels in public water system. The results showed that bigger PWS have been more effective in fluoride reduction measures than small PWS. The main methods used to lower the fluoride content were reverse osmosis technology and replacement of water sources with new ones (new drilled wells). As a result of all the measures taken the overall high-fluoride exposure has been reduced substantially (82%).

Using an Emergency Department Syndromic Surveillance System to Evaluate Reporting of Potential Rabies Exposures, Illinois, 2013-2015.

PubMed

Bemis, Kelley; Frias, Mabel; Patel, Megan Toth; Christiansen, Demian

Mandatory reporting of potential rabies exposures and initiation of postexposure prophylaxis (PEP) allow local health authorities to monitor PEP administration for errors. Our objectives were to use an emergency department (ED) syndromic surveillance system to (1) estimate reporting compliance for exposure to rabies in suburban Cook County, Illinois, and (2) initiate interventions to improve reporting and reassess compliance. We queried ED records from 45 acute care hospitals in Cook County and surrounding areas from January 1, 2013, through June 30, 2015, for chief complaints or discharge diagnoses pertaining to rabies, PEP, or contact with a wild mammal (eg, bat, raccoon, skunk, fox, or coyote). We matched patients with ≥1 ED visit for potential rabies exposure to people with potential rabies exposure reported to the Cook County Department of Public Health. We considered nonmatches to have unreported exposures. We then initiated active surveillance in July 2015, disseminated education on reporting requirements in August and September 2015, and reassessed reporting completeness from July 2015 through February 2016. Of 248 patients with rabies-related ED visits from January 2013 through June 2015, 63 (25.4%) were reported. After interventions were implemented to increase reporting compliance, 53 of 98 (54.1%) patients with rabies-related ED visits from July 2015 through February 2016 were reported. Patients with ED visits for potential rabies exposure were twice as likely to be reported postintervention than preintervention (risk ratio = 2.1; 95% CI, 1.6-2.8). The volume of potential rabies exposure cases reported to the health department from July 2015 through February 2016 increased by 252% versus the previous year. Potential rabies exposures and PEP initiation are underreported in suburban Cook County. ED syndromic surveillance records can be used to estimate reporting compliance and conduct active surveillance.

Strategies to reduce exposure of fumonisins from complementary foods in rural Tanzania.

PubMed

Kimanya, Martin E; De Meulenaer, Bruno; Van Camp, John; Baert, Katleen; Kolsteren, Patrick

2012-10-01

Feeding infants with maize can expose them to fumonisin mycotoxins. We assessed fumonisin exposure from complementary foods in rural Tanzania and determined strategies to reduce the exposure. We conducted a cross-sectional study in four villages of Tarakea division, Northern Tanzania. We used a repeat 24-hour dietary recall to collect data of maize consumption as complementary food for 254 infants aged 6-8 months. Fumonisin concentrations in the maize were also estimated. Fumonisin exposure was assessed using @risk analysis software. With the software, several maximum fumonisin contamination and maize consumption patterns were combined in order to determine effective strategies for minimizing fumonisin exposure. Of the infants, 89% consumed maize at amounts up to 158g/person/day (mean; 43g/person/day±28). The maize was contaminated with fumonisins at levels up to 3201µgkg(-1) . Risk of fumonisin intake above the provisional maximum tolerable daily limit of 2µgkg(-1) body weight was 15% (95% confidence interval; 10-19). The risk was minimized when the maximum contamination was set at 150µgkg(-1) . The risk was also minimized when the maximum consumption was set at 20g/child/day while keeping the maximum contamination at the European Union (EU) maximum tolerated limit (MTL) of 1000µgkg(-1) . Considering the economical and technological limitations of adopting good agricultural practices in rural Tanzania, it is practically difficult to reduce contamination in maize to 150µgkg(-1) . We suggest adoption of the EU MTL of 1000µgkg(-1) for fumonisins in maize and reduction, by replacement with another cereal, of the maize component in complementary foods to a maximum intake of 20g/child/day. © 2011 Blackwell Publishing Ltd.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: focus on the cancer hallmark of tumor angiogenesis

PubMed Central

Hu, Zhiwei; Brooks, Samira A.; Dormoy, Valérian; Hsu, Chia-Wen; Hsu, Hsue-Yin; Lin, Liang-Tzung; Massfelder, Thierry; Rathmell, W. Kimryn; Xia, Menghang; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Brown, Dustin G.; Prudhomme, Kalan R.; Colacci, Annamaria; Hamid, Roslida A.; Mondello, Chiara; Raju, Jayadev; Ryan, Elizabeth P.; Woodrick, Jordan; Scovassi, A. Ivana; Singh, Neetu; Vaccari, Monica; Roy, Rabindra; Forte, Stefano; Memeo, Lorenzo; Salem, Hosni K.; Lowe, Leroy; Jensen, Lasse; Bisson, William H.; Kleinstreuer, Nicole

2015-01-01

One of the important ‘hallmarks’ of cancer is angiogenesis, which is the process of formation of new blood vessels that are necessary for tumor expansion, invasion and metastasis. Under normal physiological conditions, angiogenesis is well balanced and controlled by endogenous proangiogenic factors and antiangiogenic factors. However, factors produced by cancer cells, cancer stem cells and other cell types in the tumor stroma can disrupt the balance so that the tumor microenvironment favors tumor angiogenesis. These factors include vascular endothelial growth factor, endothelial tissue factor and other membrane bound receptors that mediate multiple intracellular signaling pathways that contribute to tumor angiogenesis. Though environmental exposures to certain chemicals have been found to initiate and promote tumor development, the role of these exposures (particularly to low doses of multiple substances), is largely unknown in relation to tumor angiogenesis. This review summarizes the evidence of the role of environmental chemical bioactivity and exposure in tumor angiogenesis and carcinogenesis. We identify a number of ubiquitous (prototypical) chemicals with disruptive potential that may warrant further investigation given their selectivity for high-throughput screening assay targets associated with proangiogenic pathways. We also consider the cross-hallmark relationships of a number of important angiogenic pathway targets with other cancer hallmarks and we make recommendations for future research. Understanding of the role of low-dose exposure of chemicals with disruptive potential could help us refine our approach to cancer risk assessment, and may ultimately aid in preventing cancer by reducing or eliminating exposures to synergistic mixtures of chemicals with carcinogenic potential. PMID:26106137

A Personal Experience Reducing Radiation Exposures: Protecting Family in Kiev during the First Two Weeks after Chernobyl

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

Eremenko, Vitaly A.; Droppo, James G.

2006-08-01

The Chernobyl nuclear reactor accident occurred in 1986. The plume from the explosions and fires was highly radioactive and resulted in very high exposure levels in the surrounding regions. This paper describes how the people in Kiev, Ukraine, a city 90 miles (120 km) south of Chernobyl, and in particular one individual in that city, Professor Vitaly Eremenko, became aware of the threat before the official announcement and the steps he took to mitigate potential impacts to his immediate family. The combination of being informed and using available resources led to greatly reduced consequences for his family and, in particular,more » his newborn granddaughter. He notes how quickly word of some aspects of the hazard spread in the city and how other aspects appear to not have been understood. Although these events are being recalled as the 20th anniversary of the terrible event approaches, the lessons are still pertinent today. Threats of possible terrorist use of radiation dispersal devices makes knowledge of effective individual actions for self-protection from radiation exposures a topic of current interest.« less

Radiation safety protocol using real-time dose reporting reduces patient exposure in pediatric electrophysiology procedures.

PubMed

Patel, Akash R; Ganley, Jamie; Zhu, Xiaowei; Rome, Jonathan J; Shah, Maully; Glatz, Andrew C

2014-10-01

Radiation exposure during pediatric catheterization is significant. We sought to describe radiation exposure and the effectiveness of radiation safety protocols in reducing exposure during catheter ablations with electrophysiology studies in children and patients with congenital heart disease. We additionally sought to identify at-risk patients. We retrospectively reviewed all interventional electrophysiology procedures performed from April 2009 to September 2011 (6 months preceding intervention, 12 months following implementation of initial radiation safety protocol, and 8 months following implementation of modified protocol). The protocols consisted of low pulse rate fluoroscopy settings, operator notification of skin entrance dose every 1,000 mGy, adjusting cameras by >5 at every 1,000 mGy, and appropriate collimation. The cohort consisted of 291 patients (70 pre-intervention, 137 after initial protocol implementation, 84 after modified protocol implementation) at a median age of 14.9 years with congenital heart disease present in 11 %. Diagnoses included atrioventricular nodal reentrant tachycardia (25 %), atrioventricular reentrant tachycardia (61 %), atrial tachycardias (12 %), and ventricular tachycardia (2 %). There were no differences between groups based on patient, arrhythmia, and procedural characteristics. Following implementation of the protocols, there were significant reductions in all measures of radiation exposure: fluoroscopy time (17.8 %), dose area product (80.2 %), skin entry dose (81.0 %), and effective dose (76.9 %), p = 0.0001. Independent predictors of increased radiation exposure included larger patient weight, longer fluoroscopy time, and lack of radiation safety protocol. Implementation of a radiation safety protocol for pediatric and congenital catheter ablations can drastically reduce radiation exposure to patients without affecting procedural success.

Chronic lead exposure induces cochlear oxidative stress and potentiates noise-induced hearing loss.

PubMed

Jamesdaniel, Samson; Rosati, Rita; Westrick, Judy; Ruden, Douglas M

2018-08-01

Acquired hearing loss is caused by complex interactions of multiple environmental risk factors, such as elevated levels of lead and noise, which are prevalent in urban communities. This study delineates the mechanism underlying lead-induced auditory dysfunction and its potential interaction with noise exposure. Young-adult C57BL/6 mice were exposed to: 1) control conditions; 2) 2 mM lead acetate in drinking water for 28 days; 3) 90 dB broadband noise 2 h/day for two weeks; and 4) both lead and noise. Blood lead levels were measured by inductively coupled plasma mass spectrometry analysis (ICP-MS) lead-induced cochlear oxidative stress signaling was assessed using targeted gene arrays, and the hearing thresholds were assessed by recording auditory brainstem responses. Chronic lead exposure downregulated cochlear Sod1, Gpx1, and Gstk1, which encode critical antioxidant enzymes, and upregulated ApoE, Hspa1a, Ercc2, Prnp, Ccl5, and Sqstm1, which are indicative of cellular apoptosis. Isolated exposure to lead or noise induced 8-12 dB and 11-25 dB shifts in hearing thresholds, respectively. Combined exposure induced 18-30 dB shifts, which was significantly higher than that observed with isolated exposures. This study suggests that chronic exposure to lead induces cochlear oxidative stress and potentiates noise-induced hearing impairment, possibly through parallel pathways. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

The Contribution of Fetal Drug Exposure to Temperament: Potential Teratogenic Effects on Neuropsychiatric Risk

ERIC Educational Resources Information Center

Weiss, Sandra J.; St. Jonn-Seed, Mary; Harris-Muchell, Carolyn

2007-01-01

Background: Preliminary evidence indicates that fetal drug exposure may be associated with alterations in temperament. However, studies often do not dissociate the potential effects of drug exposure from other perinatal or environmental factors that could influence temperament phenotypes. Methods: High risk children (n = 120) were followed from…

What Are Nursing Facilities Doing to Reduce Potentially Avoidable Hospitalizations?

PubMed

Daras, Laura Coots; Wang, Joyce M; Ingber, Melvin J; Ormond, Catherine; Breg, Nathaniel W; Khatutsky, Galina; Feng, Zhanlian

2017-05-01

Hospitalizations among nursing facility residents are frequent and often potentially avoidable. A number of initiatives and interventions have been developed to reduce excessive hospitalizations; however, little is known about the specific approaches nursing facilities use to address this issue. The objective of this study is to better understand which types of interventions nursing facilities have introduced to reduce potentially avoidable hospitalizations of long-stay nursing facility residents. Cross-sectional survey. 236 nursing facilities from 7 states. Nursing facility administrators. Web-based survey to measure whether facilities introduced any policies or procedures designed specifically to reduce potentially avoidable hospitalizations of long-stay nursing facility residents between 2011 and 2015. We surveyed facilities about seven types of interventions and quality improvement activities related to reducing avoidable hospitalizations, including use of Interventions to Reduce Acute Care Transfers (INTERACT) and American Medical Directors Association tools. Ninety-five percent of responding nursing facilities reported having introduced at least one new policy or procedure to reduce nursing facility resident hospitalizations since January 2011. The most common practice reported was hospitalization rate tracking or review, followed by standardized communication tools, such as Situation, Background, Assessment, Recommendation (SBAR). We found some variation in the extent and types of these reported interventions. Nearly all facilities surveyed reported having introduced a variety of initiatives to reduce potentially avoidable hospitalizations, likely driven by federal, state, and corporate initiatives to decrease hospital admissions and readmissions. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. All rights reserved.

Effectiveness of a personalized ventilation system in reducing personal exposure against directly released simulated cough droplets.

PubMed

Pantelic, J; Tham, K W; Licina, D

2015-12-01

The inhalation intake fraction was used as an indicator to compare effects of desktop personalized ventilation and mixing ventilation on personal exposure to directly released simulated cough droplets. A cough machine was used to simulate cough release from the front, back, and side of a thermal manikin at distances between 1 and 4 m. Cough droplet concentration was measured with an aerosol spectrometer in the breathing zone of a thermal manikin. Particle image velocimetry was used to characterize the velocity field in the breathing zone. Desktop personalized ventilation substantially reduced the inhalation intake fraction compared to mixing ventilation for all investigated distances and orientations of the cough release. The results point out that the orientation between the cough source and the breathing zone of the exposed occupant is an important factor that substantially influences exposure. Exposure to cough droplets was reduced with increasing distance between cough source and exposed occupant. The results from this study show that an advanced air distribution system such as personalized ventilation reduces exposure to cough-released droplets better than commonly applied overhead mixing ventilation. This work can inform HVAC engineers about different aspects of air distribution systems’ performance and can serve as an aid in making critical design decisions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Assessing shoreline exposure and oyster habitat suitability maximizes potential success for sustainable shoreline protection using restored oyster reefs

USGS Publications Warehouse

LaPeyre, Megan K.; Serra, Kayla; Joyner, T. Andrew; Humphries, Austin T.

2015-01-01

Oyster reefs provide valuable ecosystem services that contribute to coastal resilience. Unfortunately, many reefs have been degraded or removed completely, and there are increased efforts to restore oysters in many coastal areas. In particular, much attention has recently been given to the restoration of shellfish reefs along eroding shorelines to reduce erosion. Such fringing reef approaches, however, often lack empirical data to identify locations where reefs are most effective in reducing marsh erosion, or fully take into account habitat suitability. Using monitoring data from 5 separate fringing reef projects across coastal Louisiana, we quantify shoreline exposure (fetch + wind direction + wind speed) and reef impacts on shoreline retreat. Our results indicate that fringing oyster reefs have a higher impact on shoreline retreat at higher exposure shorelines. At higher exposures, fringing reefs reduced marsh edge erosion an average of 1.0 m y−1. Using these data, we identify ranges of shoreline exposure values where oyster reefs are most effective at reducing marsh edge erosion and apply this knowledge to a case study within one Louisiana estuary. In Breton Sound estuary, we calculate shoreline exposure at 500 random points and then overlay a habitat suitability index for oysters. This method and the resulting visualization show areas most likely to support sustainable oyster populations as well as significantly reduce shoreline erosion. Our results demonstrate how site selection criteria, which include shoreline exposure and habitat suitability, are critical to ensuring greater positive impacts and longevity of oyster reef restoration projects.

Information technology-based approaches to reducing repeat drug exposure in patients with known drug allergies.

PubMed

Cresswell, Kathrin M; Sheikh, Aziz

2008-05-01

There is increasing interest internationally in ways of reducing the high disease burden resulting from errors in medicine management. Repeat exposure to drugs to which patients have a known allergy has been a repeatedly identified error, often with disastrous consequences. Drug allergies are immunologically mediated reactions that are characterized by specificity and recurrence on reexposure. These repeat reactions should therefore be preventable. We argue that there is insufficient attention being paid to studying and implementing system-based approaches to reducing the risk of such accidental reexposure. Drawing on recent and ongoing research, we discuss a number of information technology-based interventions that can be used to reduce the risk of recurrent exposure. Proven to be effective in this respect are interventions that provide real-time clinical decision support; also promising are interventions aiming to enhance patient recognition, such as bar coding, radiofrequency identification, and biometric technologies.

Orally administered fructose increases the numbers of peripheral lymphocytes reduced by exposure of mice to gamma or SPE-like proton radiation

NASA Astrophysics Data System (ADS)

Romero-Weaver, A. L.; Ni, J.; Lin, L.; Kennedy, A. R.

2014-07-01

Exposure of the whole body or a major portion of the body to ionizing radiation can result in Acute Radiation Sickness (ARS), which can cause symptoms that range from mild to severe, and include death. One of the syndromes that can occur during ARS is the hematopoietic syndrome, which is characterized by a reduction in bone marrow cells as well as the number of circulating blood cells. Doses capable of causing this syndrome can result from conventional radiation therapy and accidental exposure to ionizing radiation. It is of concern that this syndrome could also occur during space exploration class missions in which astronauts could be exposed to significant doses of solar particle event (SPE) radiation. Of particular concern is the reduction of lymphocytes and granulocytes, which are major components of the immune system. A significant reduction in their numbers can compromise the immune system, causing a higher risk for the development of infections which could jeopardize the success of the mission. Although there are no specific countermeasures utilized for the ARS resulting from exposure to space radiation(s), granulocyte colony-stimulating factor (G-CSF) has been proposed as a countermeasure for the low number of neutrophils caused by SPE radiation, but so far no countermeasure exists for a reduced number of circulating lymphocytes. The present study demonstrates that orally administered fructose significantly increases the number of peripheral lymphocytes reduced by exposure of mice to 2 Gy of gamma- or SPE-like proton radiation, making it a potential countermeasure for this biological end-point.

The contribution of fetal drug exposure to temperament: potential teratogenic effects on neuropsychiatric risk.

PubMed

Weiss, Sandra J; St Jonn-Seed, Mary; Harris-Muchell, Carolyn

2007-08-01

Preliminary evidence indicates that fetal drug exposure may be associated with alterations in temperament. However, studies often do not dissociate the potential effects of drug exposure from other perinatal or environmental factors that could influence temperament phenotypes. High risk children (n = 120) were followed from birth to 6 months of age to determine the effects of fetal drug exposure on temperament, after controlling for the child's gender, gestational age, medical morbidity, ethnicity, and maltreatment as well as the mother's stress, income adequacy, and quality of caregiving. Methods included medical chart review, questionnaires, and videotapes of mother-child interaction. Preliminary analyses indicated that fetal drug exposure was associated with both distractibility and intensity of children's responses to the environment at 6 months of age. After adjusting for potentially confounding variables, drug exposure accounted for 12% of the variance in distractibility but was not a significant predictor in the regression model for intensity. Findings suggest that drug-exposed children may experience difficulty sustaining their focus of attention and be more easily distracted by environmental stimuli than non-drug-exposed children. Results converge with previous research to implicate cortical hyperarousal, stemming from teratogenic effects on the dopaminergic system during fetal development.

Assessing children's ultraviolet radiation exposure: the potential usefulness of a colorimeter.

PubMed

Eckhardt, L; Mayer, J A; Creech, L; Johnston, M R; Lui, K J; Sallis, J F; Elder, J P

1996-12-01

This study evaluated the colorimeter as an objective measure of children's ultraviolet (UV) radiation exposure. Fifty-eight children, ages 6 to 9 years, attended two summer measurement sessions, with 46 attending a subsequent winter session. Comparisons between summer sessions for the L* scale showed that only the upper arm significantly changed in the tanner direction, while b* scale values indicated significant tanning for all body sites. All exposed body sites changed significantly in the less tan direction between summer and winter measurements. Using colorimeters to objectively measure children's UV exposure has potential applications for skin cancer prevention programs.

Exposure to sucrose during periods of withdrawal does not reduce cocaine-seeking behavior in rats.

PubMed

Nicolas, Céline; Lafay-Chebassier, Claire; Solinas, Marcello

2016-03-21

Concomitant access to drugs of abuse and alternative rewards such as sucrose has been shown to decrease addiction-related behaviors in animals. Here we investigated whether access to sucrose during abstinence in contexts that are temporally and physically distinct from drug-related contexts could reduce subsequent drug seeking. In addition, we investigated whether a history of cocaine self-administration would alter the rewarding effects of sucrose. Rats self-administered cocaine for ten sessions, while yoked-saline rats received only saline injections, and then we subjected them to a 30-day withdrawal period during which they had access to water and sucrose continuously or intermittently according to a schedule that induces binge-drinking behavior. At the end of the withdrawal period, rats were tested for cocaine seeking behavior during a single 6 h session. We found that exposure to cocaine increased sucrose consumption only when rats had intermittent access to sucrose, but exposure to sucrose did not alter drug seeking regardless of the schedule of access. These results suggest that exposure to cocaine cross-sensitizes to the rewarding effects of sucrose, but exposure to sucrose during abstinence, temporally and physically distinct from drug-related environments, does not to reduce drug seeking.

A Complex Interaction Between Reduced Reelin Expression and Prenatal Organophosphate Exposure Alters Neuronal Cell Morphology.

PubMed

Mullen, Brian R; Ross, Brennan; Chou, Joan Wang; Khankan, Rana; Khialeeva, Elvira; Bui, Kimberly; Carpenter, Ellen M

2016-06-01

Genetic and environmental factors are both likely to contribute to neurodevelopmental disorders including schizophrenia, autism spectrum disorders, and major depressive disorders. Prior studies from our laboratory and others have demonstrated that the combinatorial effect of two factors-reduced expression of reelin protein and prenatal exposure to the organophosphate pesticide chlorpyrifos oxon-gives rise to acute biochemical effects and to morphological and behavioral phenotypes in adolescent and young adult mice. In the current study, we examine the consequences of these factors on reelin protein expression and neuronal cell morphology in adult mice. While the cell populations that express reelin in the adult brain appear unchanged in location and distribution, the levels of full length and cleaved reelin protein show persistent reductions following prenatal exposure to chlorpyrifos oxon. Cell positioning and organization in the hippocampus and cerebellum are largely normal in animals with either reduced reelin expression or prenatal exposure to chlorpyrifos oxon, but cellular complexity and dendritic spine organization is altered, with a skewed distribution of immature dendritic spines in adult animals. Paradoxically, combinatorial exposure to both factors appears to generate a rescue of the dendritic spine phenotypes, similar to the mitigation of behavioral and morphological changes observed in our prior study. Together, our observations support an interaction between reelin expression and chlorpyrifos oxon exposure that is not simply additive, suggesting a complex interplay between genetic and environmental factors in regulating brain morphology. © The Author(s) 2016.

Reducing unwanted trauma memories by imaginal exposure or autobiographical memory elaboration: An analogue study of memory processes

PubMed Central

Ehlers, Anke; Mauchnik, Jana; Handley, Rachel

2012-01-01

Unwanted memories of traumatic events are a core symptom of post-traumatic stress disorder. A range of interventions including imaginal exposure and elaboration of the trauma memory in its autobiographical context are effective in reducing such unwanted memories. This study explored whether priming for stimuli that occur in the context of trauma and evaluative conditioning may play a role in the therapeutic effects of these procedures. Healthy volunteers (N = 122) watched analogue traumatic and neutral picture stories. They were then randomly allocated to 20 min of either imaginal exposure, autobiographical memory elaboration, or a control condition designed to prevent further processing of the picture stories. A blurred picture identification task showed that neutral objects that preceded traumatic pictures in the stories were subsequently more readily identified than those that had preceded neutral stories, indicating enhanced priming. There was also an evaluative conditioning effect in that participants disliked neutral objects that had preceded traumatic pictures more. Autobiographical memory elaboration reduced the enhanced priming effect. Both interventions reduced the evaluative conditioning effect. Imaginal exposure and autobiographical memory elaboration both reduced the frequency of subsequent unwanted memories of the picture stories. PMID:21227404

A Community-Based Initiative to Reduce Children's Exposure to Toxics in Household Products

ERIC Educational Resources Information Center

Blackman, Anne Berlin; Luskin, Jack

2006-01-01

Purpose--The purpose of this paper is to explore the efficacy of a community-based outreach initiative, piloted in Worcester, Massachusetts, to reduce children's exposure to toxic chemicals in common household products by changing parental behavior regarding product purchase and use. Design/methodology/approach--The program model was based on the…

A decision tree approach to screen drinking water contaminants for multiroute exposure potential in developing guideline values.

PubMed

Krishnan, Kannan; Carrier, Richard

2017-07-03

The consideration of inhalation and dermal routes of exposures in developing guideline values for drinking water contaminants is important. However, there is no guidance for determining the eligibility of a drinking water contaminant for its multiroute exposure potential. The objective of the present study was to develop a 4-step framework to screen chemicals for their dermal and inhalation exposure potential in the process of developing guideline values. The proposed framework emphasizes the importance of considering basic physicochemical properties prior to detailed assessment of dermal and inhalation routes of exposure to drinking water contaminants in setting guideline values.

Prenatal phthalate exposure and reduced masculine play in boys.

PubMed

Swan, S H; Liu, F; Hines, M; Kruse, R L; Wang, C; Redmon, J B; Sparks, A; Weiss, B

2010-04-01

a small sample, suggest that prenatal exposure to antiandrogenic phthalates may be associated with less male-typical play behaviour in boys. Our findings suggest that these ubiquitous environmental chemicals have the potential to alter androgen-responsive brain development in humans.

Suspended particles only marginally reduce pyrethroid toxicity to the freshwater invertebrate Gammarus pulex (L.) during pulse exposure.

PubMed

Rasmussen, Jes Jessen; Cedergreen, Nina; Kronvang, Brian; Andersen, Maj-Britt Bjergager; Nørum, Ulrik; Kretschmann, Andreas; Strobel, Bjarne Westergaard; Hansen, Hans Christian Bruun

2016-04-01

Current ecotoxicological research on particle-associated pyrethroids in freshwater systems focuses almost exclusively on sediment-exposure scenarios and sediment-dwelling macroinvertebrates. We studied how suspended particles influence acute effects of lambda-cyhalothrin and bifenthrin on the epibenthic freshwater amphipod Gammarus pulex (L.) using brief pulse exposures followed by a 144 h post exposure recovery phase. Humic acid (HA) and the clay mineral montmorillonite (MM) were used as model sorbents in environmentally realistic concentrations (5, 25 and 125 mg L(-1)). Mortality of G. pulex was recorded during the post exposure recovery phase and locomotor behavior was measured during exposure to lambda-cyhalothrin. We found that HA in concentrations ≥25 mg L(-1) adsorbed the majority of pyrethroids but only reduced mortality of G. pulex up to a factor of four compared to pyrethroid-only treatments. MM suspensions adsorbed a variable fraction of pyrethroids (10% for bifenthrin and 70% for lambda-cyhalothrin) but did not significantly change the concentration-response relationship compared to pure pyrethroid treatments. Behavioral responses and immobilisation rate of G. pulex were reduced in the presence of HA, whereas behavioral responses and immobilisation rate were increased in the presence of MM. This indicates that G. pulex was capable of sensing the bioavailable fraction of lambda-cyhalothrin. Our results imply that suspended particles reduce to only a limited extent the toxicity of pyrethroids to G. pulex and that passive uptake of pyrethroids can be significant even when pyrethroids are adsorbed to suspended particles.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: focus on the cancer hallmark of tumor angiogenesis.

PubMed

Hu, Zhiwei; Brooks, Samira A; Dormoy, Valérian; Hsu, Chia-Wen; Hsu, Hsue-Yin; Lin, Liang-Tzung; Massfelder, Thierry; Rathmell, W Kimryn; Xia, Menghang; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Brown, Dustin G; Prudhomme, Kalan R; Colacci, Annamaria; Hamid, Roslida A; Mondello, Chiara; Raju, Jayadev; Ryan, Elizabeth P; Woodrick, Jordan; Scovassi, A Ivana; Singh, Neetu; Vaccari, Monica; Roy, Rabindra; Forte, Stefano; Memeo, Lorenzo; Salem, Hosni K; Lowe, Leroy; Jensen, Lasse; Bisson, William H; Kleinstreuer, Nicole

2015-06-01

One of the important 'hallmarks' of cancer is angiogenesis, which is the process of formation of new blood vessels that are necessary for tumor expansion, invasion and metastasis. Under normal physiological conditions, angiogenesis is well balanced and controlled by endogenous proangiogenic factors and antiangiogenic factors. However, factors produced by cancer cells, cancer stem cells and other cell types in the tumor stroma can disrupt the balance so that the tumor microenvironment favors tumor angiogenesis. These factors include vascular endothelial growth factor, endothelial tissue factor and other membrane bound receptors that mediate multiple intracellular signaling pathways that contribute to tumor angiogenesis. Though environmental exposures to certain chemicals have been found to initiate and promote tumor development, the role of these exposures (particularly to low doses of multiple substances), is largely unknown in relation to tumor angiogenesis. This review summarizes the evidence of the role of environmental chemical bioactivity and exposure in tumor angiogenesis and carcinogenesis. We identify a number of ubiquitous (prototypical) chemicals with disruptive potential that may warrant further investigation given their selectivity for high-throughput screening assay targets associated with proangiogenic pathways. We also consider the cross-hallmark relationships of a number of important angiogenic pathway targets with other cancer hallmarks and we make recommendations for future research. Understanding of the role of low-dose exposure of chemicals with disruptive potential could help us refine our approach to cancer risk assessment, and may ultimately aid in preventing cancer by reducing or eliminating exposures to synergistic mixtures of chemicals with carcinogenic potential. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

JP-8 jet fuel exposure potentiates tumor development in two experimental model systems.

PubMed

Harris, D T; Sakiestewa, D; Titone, D; He, X; Hyde, J; Witten, M

2007-11-01

The US Air Force has implemented the widespread use of JP-8 jet fuel in its operations, although a thorough understanding of its potential effects upon exposed personnel is unclear. Previous work has reported that JP-8 exposure is immunosuppressive. Exposure of mice to JP-8 for 1 h/day resulted in immediate secretion of two immunosuppressive agents; namely, interleukin-10 (IL-10) and prostaglandin E2 (PGE2). Thus, it was of interest to determine if jet fuel exposure might promote tumor growth and metastasis. The syngeneic B16 tumor model was used for these studies. Animals were injected intravenously with tumor cells, and lung colonies were enumerated. Animals were also examined for metastatic spread of the tumor. Mice were either exposed to 1000 mg/m3 JP-8 (1 h/ day) for 7 days before tumor injection or were exposed to JP-8 at the time of tumor injection. All animals were killed 17 days after tumor injection. In the present study, JP8 exposure potentiated the growth and metastases of B16 tumors in an animal model. Exposure of mice to JP-8 for 1 h/day before tumor induction resulted in an approximately 8.7-fold increase in tumors, whereas those mice exposed to JP8 at the time of tumor induction had a 5.6-fold increase in tumor numbers. Thus, low concentration JP-8 jet fuel exposures have significant immune suppressive effects on the immune system that can result in increased tumor formation and metastases. We have now extended the observations to an experimental subcutaneous tumor model. JP8 exposure at the time of tumor induction in this model did not affect the growth of the tumor. However, JP8-exposed, tumor-bearing animals died at an accelerated rate as compared with air-exposed, tumor-bearing mice.

Health impact assessment of a skin sensitizer: Analysis of potential policy measures aimed at reducing geraniol concentrations in personal care products and household cleaning products.

PubMed

Jongeneel, W P; Delmaar, J E; Bokkers, B G H

2018-06-08

A methodology to assess the health impact of skin sensitizers is introduced, which consists of the comparison of the probabilistic aggregated exposure with a probabilistic (individual) human sensitization or elicitation induction dose. The health impact of potential policy measures aimed at reducing the concentration of a fragrance allergen, geraniol, in consumer products is analysed in a simulated population derived from multiple product use surveys. Our analysis shows that current dermal exposure to geraniol from personal care and household cleaning products lead to new cases of contact allergy and induce clinical symptoms for those already sensitized. We estimate that this exposure results yearly in 34 new cases of geraniol contact allergy per million consumers in Western and Northern Europe, mainly due to exposure to household cleaning products. About twice as many consumers (60 per million) are projected to suffer from clinical symptoms due to re-exposure to geraniol. Policy measures restricting geraniol concentrations to <0.01% will noticeably reduce new cases of sensitization and decrease the number of people with clinical symptoms as well as the frequency of occurrence of these clinical symptoms. The estimated numbers should be interpreted with caution and provide only a rough indication of the health impact. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Assessing the impact of in-utero exposures: potential effects of paracetamol on male reproductive development.

PubMed

Kilcoyne, Karen R; Mitchell, Rod T

2017-12-01

Human male reproductive disorders (cryptorchidism, hypospadias, testicular cancer and low sperm counts) are common and some may be increasing in incidence worldwide. These associated disorders can arise from subnormal testosterone production during fetal life. This has resulted in a focus on in-utero environmental influences that may result in reproductive effects on the offspring in later life. Over recent years, there has been a dramatic increase in the scientific literature describing associations between in-utero environmental exposures (eg, industrial chemicals and pharmaceuticals) and subsequent reproductive outcomes in male offspring. This includes studies investigating a potential role for in-utero analgesic exposure(s) on the fetal testis; however, providing definitive evidence of such effects presents numerous challenges. In this review, we describe an approach to assessing the potential clinical relevance of in-utero (and postnatal) environmental exposures on subsequent male reproductive function using exposure to the analgesic paracetamol as an example. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Randomized comparison of group versus individual educational interventions for pregnant women to reduce their secondhand smoke exposure.

PubMed

Chi, Ying-Chen; Sha, Feng; Yip, Paul S F; Chen, Jiunn-Liang; Chen, Ying-Yeh

2016-10-01

Secondhand smoke (SHS) exposure is deleterious to pregnant women and their unborn children. The prevalence of SHS exposure among pregnant women is particularly high in many Asian countries where approximately half of the male population smokes. We aim to investigate the efficacy of an intervention based on an expanded Health Belief Model (HBM) incorporating self-efficacy to educate and empower pregnant women to reduce their SHS exposure. We conducted a 3-arm randomized controlled trial (N = 50 in each arm) comparing the effectiveness of group-based and individual-based interventions with a treatment-as-usual group. A questionnaire tapping into constructs of the expanded HBM was administered at baseline and 1- and 2-month follow-ups. Exhaled carbon monoxide was used to determine SHS exposure (>=6 ppm). ANOVA was used to compare HBM construct scores, self-efficacy for rejecting SHS exposure, and SHS rejection behavior among the 3 groups at baseline and the 1- and 2-month follow-ups, while logistic regression analysis was used to compare the risk of exposure to SHS at each follow-up. The group-based intervention significantly improved health beliefs, self-efficacy, and self-reported rejection behaviors. The individual-based intervention effect was limited to some health belief constructs and SHS rejection behaviors. Both group- and individual-based interventions showed significant reductions in SHS exposure 2 months after the intervention (P < 0.0001). Group-based educational interventions based on the HBM are particularly effective in training pregnant women to avoid and refuse exposure to SHS. Policy makers should consider offering group-delivered programs to educate and empower pregnant women to reduce their SHS exposure.

Time reducing exposure containing 18 fluorine flourodeoxyglucose master vial dispensing in hot lab: Omega technique

PubMed Central

Rao, Vatturi Venkata Satya Prabhakar; Manthri, Ranadheer; Hemalatha, Pottumuthu; Kumar, Vuyyuru Navin; Azhar, Mohammad

2016-01-01

Hot lab dispensing of large doses of 18 fluorine fluorodeoxyglucose in master vials supplied from the cyclotrons requires high degrees of skill to handle high doses. Presently practiced conventional method of fractionating from the inverted tiltable vial pig mounted on a metal frame has its own limitations such as increasing isotope handling times and exposure to the technologist. Innovative technique devised markedly improves the fractionating efficiency along with speed, precision, and reduced dose exposure. PMID:27095872

Frontal auditory evoked potentials and augmenting-reducing.

PubMed

Bruneau, N; Roux, S; Garreau, B; Lelord, G

1985-09-01

Auditory evoked potentials (AEPs) to tones (750 Hz--200 msec) ranging from 50 to 80 dB SPL were studied at Cz and Fz leads in 29 normal adults (15 males) ranging in age from 20 to 22. Peak-to-trough amplitudes were measured for the P1-N1 and the N1-P2 wave forms as well as baseline (500 msec prestimulus)-to-peak amplitudes for each component, i.e., P1, N1 and P2. Amplitudes were examined as a function of intensity and electrode location. Cz-Fz amplitude differences increased with increasing stimulus intensity, the differentiating peak being the N1 component. An overall reducing phenomenon was found at Fz in the 70-80 dB range whereas an augmenting effect was observed at Cz for these intensities. The augmenting/reducing groups defined by analysis of individual amplitude-intensity patterns were different whether we considered Fz or Cz results: Fz reducers were more numerous than Cz reducers. These results on prominent reducing at the frontal level were examined in relation to the data concerning the modulatory function of the frontal cortex on auditory EPs. Implications were drawn for the role of the frontal cortex in cortical augmenting-reducing.

Prolonged exposure to acetaminophen reduces testosterone production by the human fetal testis in a xenograft model

PubMed Central

Anderson, Richard A.; Johnston, Zoe C.; Chetty, Tarini; Smith, Lee B.; Mckinnell, Chris; Dean, Afshan; Homer, Natalie Z.; Jorgensen, Anne; Camacho-Moll, Maria-Elena; Sharpe, Richard M.; Mitchell, Rod T.

2016-01-01

Most common male reproductive disorders are linked to lower testosterone exposure in fetal life, although the factors responsible for suppressing fetal testosterone remain largely unknown. Protracted use of acetaminophen during pregnancy is associated with increased risk of cryptorchidism in sons, but effects on fetal testosterone production have not been demonstrated. We used a validated xenograft model to expose human fetal testes to clinically relevant doses and regimens of acetaminophen. Exposure to a therapeutic dose of acetaminophen for 7 days significantly reduced plasma testosterone (45% reduction; p=0.025) and seminal vesicle weight (a biomarker of androgen exposure; 18% reduction; p=0.005) in castrate host mice bearing human fetal testis xenografts, whereas acetaminophen exposure for just 1 day did not alter either parameter. Plasma acetaminophen concentrations (at 1 hour after the final dose) in exposed host mice were substantially below those reported in humans after a therapeutic oral dose. Subsequent in utero exposure studies in rats indicated that the acetaminophen-induced reduction in testosterone likely results from reduced expression of key steroidogenic enzymes (Cyp11a1, Cyp17a1). Our results suggest that protracted use of acetaminophen (1 week) may suppress fetal testosterone production, which could have adverse consequences. Further studies are required to establish the dose-response and treatment-duration relationships to delineate the maximum dose and treatment period without this adverse effect. PMID:25995226

Assessing children's ultraviolet radiation exposure: the potential usefulness of a colorimeter.

PubMed Central

Eckhardt, L; Mayer, J A; Creech, L; Johnston, M R; Lui, K J; Sallis, J F; Elder, J P

1996-01-01

OBJECTIVES: This study evaluated the colorimeter as an objective measure of children's ultraviolet (UV) radiation exposure. METHODS: Fifty-eight children, ages 6 to 9 years, attended two summer measurement sessions, with 46 attending a subsequent winter session. RESULTS: Comparisons between summer sessions for the L* scale showed that only the upper arm significantly changed in the tanner direction, while b* scale values indicated significant tanning for all body sites. All exposed body sites changed significantly in the less tan direction between summer and winter measurements. CONCLUSIONS: Using colorimeters to objectively measure children's UV exposure has potential applications for skin cancer prevention programs. PMID:9003142

THE POTENTIAL FOR HUMAN EXPOSURES TO PET-BORNE DIAZINON RESIDUES FOLLOWING RESIDENTIAL LAWN APPLICATIONS

EPA Science Inventory

This observational study examined the potential for indoor/outdoor pet dogs to be an important pathway for transporting diazinon residues into homes and onto occupants following residential lawn applications. The primary objective was to investigate the potential exposures of chi...

Reducing capacities and redox potentials of humic substances extracted from sewage sludge.

PubMed

Yang, Zhen; Du, Mengchan; Jiang, Jie

2016-02-01

Humic substances (HS) are redox active organic materials that can be extracted from sewage sludge generated in wastewater treatment processes. Due to the poor understanding of reducing capacity, redox potentials and redox active functional groups of HS in sewage sludge, the potential contribution of sludge HS in transformation of wastewater contaminants is unclear. In the present study, the number of electrons donated or accepted by sewage sludge HS were quantified before and after reduction by iron compounds that possess different redox potentials and defined as the reducing capacity of the sewage sludge. In contrast to previous studies of soil and commercial humic acids (HA), reduced sludge HA showed a lower reducing capacity than that of native HA, which implies formation of semiquinone radicals since the semiquinone radical/hydroquinone pair has a much higher redox potential than the quinone/hydroquinone pair. It is novel that reducing capacities of sludge HA were determined in the redox potential range from -314 to 430 mV. The formation of semiquinone radicals formed during the reduction of quinone moieties in sludge HA is shown by three-dimensional excitation/emission matrix fluorescence spectroscopies information, increasing fluorescence intensities and blue-shifting of the excitation/emission peak of reduced sludge HA. Knowledge of sludge HS redox potentials and corresponding reducing capacities makes it possible to predict the transformation of redox active pollutants and facilitate manipulation and optimization of sludge loading wastewater treatment processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reducing children's exposure to school bus diesel exhaust in one school district in North Carolina.

PubMed

Mazer, Mary E; Vann, Julie C Jacobson; Lamanna, Beth F; Davison, Jean

2014-04-01

Children who are exposed to diesel exhaust from idling school buses are at increased risk of asthma exacerbation, decreased lung function, immunologic reactions, leukemia, and increased susceptibility to infections. Policies and initiatives that aim to protect school children from the harmful effects of exposure to diesel exhaust range from general environmental air quality standards to more specific legislation that targets diesel exhaust near school children. School nurse standards of practice specify that school nurses should attain current knowledge of environmental health concepts, implement environmental health strategies, and advocate for environmental health principles. This article provides a description of the professional responsibilities of school nurses in protecting children from harmful environmental exposures, provides an overview of legislative initiatives intended to protect school children from diesel exhaust exposure, and summarizes one school district's effort to reduce diesel exhaust exposure among school children.

Observed use of voluntary controls to reduce physical exposures among sheet metal workers of the mechanical trade

PubMed Central

Dale, Ann Marie; Miller, Kim; Gardner, Bethany T.; Hwang, Ching-Ting; Evanoff, Bradley; Welch, Laura

2015-01-01

Introduction Little is known about the transfer into the workplace of interventions designed to reduce the physical demands of sheet metal workers. Methods We reviewed videos from a case series of 15 sheet metal worksite assessments performed in 2007–2009 to score postures and physical loads, and to observe the use of recommended interventions to reduce physical exposures in sheet metal activities made by a NIOSH stakeholder meeting in 2002. Results Workers showed consistent use of material handling devices, but we observed few uses of recommended interventions to reduce exposures during overhead work. Workers spent large proportions of time in awkward shoulder elevation and low back rotation postures. Conclusions In addition to the development of new technologies and system designs, increased adoption of existing tools and practices could reduce time spent in awkward postures and other risks for musculoskeletal disorders in sheet metal work. PMID:26360196

Did smokefree legislation in England reduce exposure to secondhand smoke among nonsmoking adults? Cotinine analysis from the Health Survey for England.

PubMed

Sims, Michelle; Mindell, Jennifer S; Jarvis, Martin J; Feyerabend, Colin; Wardle, Heather; Gilmore, Anna

2012-03-01

On 1 July 2007, smokefree legislation was implemented in England, which made virtually all enclosed public places and workplaces smokefree. We examined trends in and predictors of secondhand smoke exposure among nonsmoking adults to determine whether exposure changed after the introduction of smokefree legislation and whether these changes varied by socioeconomic status (SES) and by household smoking status. We analyzed salivary cotinine data from the Health Survey for England that were collected in 7 of 11 annual surveys undertaken between 1998 and 2008. We conducted multivariate regression analyses to examine secondhand smoke exposure as measured by the proportion of nonsmokers with undetectable levels of cotinine and by geometric mean cotinine. Secondhand smoke exposure was higher among those exposed at home and among lower-SES groups. Exposure declined markedly from 1998 to 2008 (the proportion of participants with undetectable cotinine was 2.9 times higher in the last 6 months of 2008 compared with the first 6 months of 1998 and geometric mean cotinine declined by 80%). We observed a significant fall in exposure after legislation was introduced--the odds of having undetectable cotinine were 1.5 times higher [95% confidence interval (CI): 1.3, 1.8] and geometric mean cotinine fell by 27% (95% CI: 17%, 36%) after adjusting for the prelegislative trend and potential confounders. Significant reductions were not, however, seen in those living in lower-social class households or homes where smoking occurs inside on most days. We found that the impact of England's smokefree legislation on secondhand smoke exposure was above and beyond the underlying long-term decline in secondhand smoke exposure and demonstrates the positive effect of the legislation. Nevertheless, some population subgroups appear not to have benefitted significantly from the legislation. This finding suggests that these groups should receive more support to reduce their exposure.

Did Smokefree Legislation in England Reduce Exposure to Secondhand Smoke among Nonsmoking Adults? Cotinine Analysis from the Health Survey for England

PubMed Central

Mindell, Jennifer S.; Jarvis, Martin J.; Feyerabend, Colin; Wardle, Heather; Gilmore, Anna

2011-01-01

Background On 1 July 2007, smokefree legislation was implemented in England, which made virtually all enclosed public places and workplaces smokefree. Objectives We examined trends in and predictors of secondhand smoke exposure among nonsmoking adults to determine whether exposure changed after the introduction of smokefree legislation and whether these changes varied by socioeconomic status (SES) and by household smoking status. Methods We analyzed salivary cotinine data from the Health Survey for England that were collected in 7 of 11 annual surveys undertaken between 1998 and 2008. We conducted multivariate regression analyses to examine secondhand smoke exposure as measured by the proportion of nonsmokers with undetectable levels of cotinine and by geometric mean cotinine. Results Secondhand smoke exposure was higher among those exposed at home and among lower-SES groups. Exposure declined markedly from 1998 to 2008 (the proportion of participants with undetectable cotinine was 2.9 times higher in the last 6 months of 2008 compared with the first 6 months of 1998 and geometric mean cotinine declined by 80%). We observed a significant fall in exposure after legislation was introduced—the odds of having undetectable cotinine were 1.5 times higher [95% confidence interval (CI): 1.3, 1.8] and geometric mean cotinine fell by 27% (95% CI: 17%, 36%) after adjusting for the prelegislative trend and potential confounders. Significant reductions were not, however, seen in those living in lower-social class households or homes where smoking occurs inside on most days. Conclusions We found that the impact of England’s smokefree legislation on secondhand smoke exposure was above and beyond the underlying long-term decline in secondhand smoke exposure and demonstrates the positive effect of the legislation. Nevertheless, some population subgroups appear not to have benefitted significantly from the legislation. This finding suggests that these groups should receive more

Biomarkers of acute respiratory allergen exposure: Screening for sensitization potential

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

Pucheu-Haston, Cherie M., E-mail: Pucheu-Haston.Cherie@epa.go; Copeland, Lisa B.; Vallanat, Beena

2010-04-15

Effective hazard screening will require the development of high-throughput or in vitro assays for the identification of potential sensitizers. The goal of this preliminary study was to identify potential biomarkers that differentiate the response to allergens vs non-allergens following an acute exposure in naive individuals. Female BALB/c mice received a single intratracheal aspiration exposure to Metarhizium anisopliae crude antigen (MACA) or bovine serum albumin (BSA) in Hank's Balanced Salt Solution (HBSS) or HBSS alone. Mice were terminated after 1, 3, 6, 12, 18 and 24 h. Bronchoalveolar lavage fluid (BALF) was evaluated to determine total and differential cellularity, total proteinmore » concentration and LDH activity. RNA was isolated from lung tissue for microarray analysis and qRT-PCR. MACA administration induced a rapid increase in BALF neutrophils, lymphocytes, eosinophils and total protein compared to BSA or HBSS. Microarray analysis demonstrated differential expression of genes involved in cytokine production, signaling, inflammatory cell recruitment, adhesion and activation in 3 and 12 h MACA-treated samples compared to BSA or HBSS. Further analyses allowed identification of approx 100 candidate biomarker genes. Eleven genes were selected for further assessment by qRT-PCR. Of these, 6 demonstrated persistently increased expression (Ccl17, Ccl22, Ccl7, Cxcl10, Cxcl2, Saa1), while C3ar1 increased from 6-24 h. In conclusion, a single respiratory exposure of mice to an allergenic mold extract induces an inflammatory response which is distinct in phenotype and gene transcription from the response to a control protein. Further validation of these biomarkers with additional allergens and irritants is needed. These biomarkers may facilitate improvements in screening methods.« less

Lung Function in Rural Guatemalan Women Before and After a Chimney Stove Intervention to Reduce Wood Smoke Exposure: Results From the Randomized Exposure Study of Pollution Indoors and Respiratory Effects and Chronic Respiratory Effects of Early Childhood Exposure to Respirable Particulate Matter Study.

PubMed

Guarnieri, Michael; Diaz, Esperanza; Pope, Daniel; Eisen, Ellen A; Mann, Jennifer; Smith, Kirk R; Smith-Sivertsen, Tone; Bruce, Nigel G; Balmes, John R

2015-11-01

COPD is the third most frequent cause of death globally, with much of this burden attributable to household biomass smoke exposure in developing countries. As biomass smoke exposure is also associated with cardiovascular disease, lower respiratory infection, lung cancer, and cataracts, it presents an important target for public health intervention. Lung function in Guatemalan women exposed to wood smoke from open fires was measured throughout the Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) stove intervention trial and continued during the Chronic Respiratory Effects of Early Childhood Exposure to Respirable Particulate Matter (CRECER) cohort study. In RESPIRE, early stove households received a chimney woodstove at the beginning of the 18-month trial, and delayed stove households received a stove at trial completion. Personal exposure to wood smoke was assessed with exhaled breath carbon monoxide (CO) and personal CO tubes. Change in lung function between intervention groups and as a function of wood smoke exposure was assessed using random effects models. Of 306 women participating in both studies, acceptable spirometry was collected in 129 early stove and 136 delayed stove households (n = 265), with a mean follow-up of 5.6 years. Despite reduced wood smoke exposures in early stove households, there were no significant differences in any of the measured spirometric variables during the study period (FEV1, FVC, FEV1/FVC ratio, and annual change) after adjustment for confounding. In these young Guatemalan women, there was no association between lung function and early randomization to a chimney stove or personal wood smoke exposure. Future stove intervention trials should incorporate cleaner stoves, longer follow-up, or potentially susceptible groups to identify meaningful differences in lung function.

Cadmium: Simulation of environmental control strategies to reduce exposure

NASA Astrophysics Data System (ADS)

Yost, K. J.; Miles, L. J.; Greenkorn, R. A.

1981-07-01

The effects of selected environmental control strategies on human dietary and respiratory exposure to environmental cadmium (Cd) have been simulated. For each control strategy, mean Cd dietary and respiratory exposures are presented for a twenty-year simulation period. Human exposures related to cadmium are associated with both process waste disposal and product disposal. Dietary exposure is by far the dominant mechanism for Cd intake. Dietary exposure related to aqueous discharges is primarily a result of municipal sludge landspreading, whereas that associated with emissions to the atmosphere derives mainly from the deposition on cropland of airborne particulates from product incineration. Only relatively small dietary exposure reductions are possible through restrictions on any single Cd use. Combinations of waste management and environmental control measures promise greater reductions in dietary and respiratory exposure than those achievable through use restrictions.

Pre-exposure to food temptation reduces subsequent consumption: A test of the procedure with a South-African sample.

PubMed

Duh, Helen Inseng; Grubliauskiene, Aiste; Dewitte, Siegfried

2016-01-01

It has been suggested that the consumption of unhealthy Westernized diet in a context of poverty and resultant food insecurity may have contributed to South-Africa's status of the third fattest country in the World. Considering that a number of South-Africans are reported to have experienced, or are still experiencing food insecurity, procedures which have been shown to reduce the consumption of unhealthy food in higher income countries may be ineffective in South-Africa. We thus tested the robustness of the so called pre-exposure procedure in South-Africa. We also tested the moderating role of childhood poverty in the pre-exposure procedure. With the pre-exposure procedure, a respondent is exposed to a tempting unhealthy food (e.g. candy) in a context that is designed such that eating the food interferes with a task goal. The typical result is that this procedure spills over and reduces consumption of similar tempting food later on. An experimental study conducted in a South-African laboratory showed that the pre-exposure effect is robust even with a sample, where food insecurity prevails. Childhood poverty did not moderate the effect. This study proves that behavioral procedures aimed at reducing the consumption of unhealthy food would be valuable in less rich non-Western countries. Further testing of the robustness of the pre-exposure effect is however recommended in other poorer food insecure countries. Copyright © 2015 Elsevier Ltd. All rights reserved.

Exposure to crude oil micro-droplets causes reduced food uptake in copepods associated with alteration in their metabolic profiles.

PubMed

Hansen, Bjørn Henrik; Altin, Dag; Nordtug, Trond; Øverjordet, Ida Beathe; Olsen, Anders J; Krause, Dan; Størdal, Ingvild; Størseth, Trond R

2017-03-01

Acute oil spills and produced water discharges may cause exposure of filter-feeding pelagic organisms to micron-sized dispersed oil droplets. The dissolved oil components are expected to be the main driver for oil dispersion toxicity; however, very few studies have investigated the specific contribution of oil droplets to toxicity. In the present work, the contribution of oil micro-droplet toxicity in dispersions was isolated by comparing exposures to oil dispersions (water soluble fraction with droplets) to concurrent exposure to filtered dispersions (water-soluble fractions without droplets). Physical (coloration) and behavioral (feeding activity) as well as molecular (metabolite profiling) responses to oil exposures in the copepod Calanus finmarchicus were studied. At high dispersion concentrations (4.1-5.6mg oil/L), copepods displayed carapace discoloration and reduced swimming activity. Reduced feeding activity, measured as algae uptake, gut filling and fecal pellet production, was evident also for lower concentrations (0.08mg oil/L). Alterations in metabolic profiles were also observed following exposure to oil dispersions. The pattern of responses were similar between two comparable experiments with different oil types, suggesting responses to be non-oil type specific. Furthermore, oil micro-droplets appear to contribute to some of the observed effects triggering a starvation-type response, manifested as a reduction in metabolite (homarine, acetylcholine, creatine and lactate) concentrations in copepods. Our work clearly displays a relationship between crude oil micro-droplet exposure and reduced uptake of algae in copepods. Copyright © 2017 Elsevier B.V. All rights reserved.

Reduced growth of soybean seedlings after exposure to weak microwave radiation from GSM 900 mobile phone and base station.

PubMed

Halgamuge, Malka N; Yak, See Kye; Eberhardt, Jacob L

2015-02-01

The aim of this work was to study possible effects of environmental radiation pollution on plants. The association between cellular telephone (short duration, higher amplitude) and base station (long duration, very low amplitude) radiation exposure and the growth rate of soybean (Glycine max) seedlings was investigated. Soybean seedlings, pre-grown for 4 days, were exposed in a gigahertz transverse electromagnetic cell for 2 h to global system for mobile communication (GSM) mobile phone pulsed radiation or continuous wave (CW) radiation at 900 MHz with amplitudes of 5.7 and 41 V m(-1) , and outgrowth was studied one week after exposure. The exposure to higher amplitude (41 V m(-1)) GSM radiation resulted in diminished outgrowth of the epicotyl. The exposure to lower amplitude (5.7 V m(-1)) GSM radiation did not influence outgrowth of epicotyl, hypocotyls, or roots. The exposure to higher amplitude CW radiation resulted in reduced outgrowth of the roots whereas lower CW exposure resulted in a reduced outgrowth of the hypocotyl. Soybean seedlings were also exposed for 5 days to an extremely low level of radiation (GSM 900 MHz, 0.56 V m(-1)) and outgrowth was studied 2 days later. Growth of epicotyl and hypocotyl was found to be reduced, whereas the outgrowth of roots was stimulated. Our findings indicate that the observed effects were significantly dependent on field strength as well as amplitude modulation of the applied field. © 2015 Wiley Periodicals, Inc.

The Eng1 β-Glucanase Enhances Histoplasma Virulence by Reducing β-Glucan Exposure

PubMed Central

Garfoot, Andrew L.; Shen, Qian; Wüthrich, Marcel; Klein, Bruce S.

2016-01-01

ABSTRACT The fungal pathogen Histoplasma capsulatum parasitizes host phagocytes. To avoid antimicrobial immune responses, Histoplasma yeasts must minimize their detection by host receptors while simultaneously interacting with the phagocyte. Pathogenic Histoplasma yeast cells, but not avirulent mycelial cells, secrete the Eng1 protein, which is a member of the glycosylhydrolase 81 (GH81) family. We show that Histoplasma Eng1 is a glucanase that hydrolyzes β-(1,3)-glycosyl linkages but is not required for Histoplasma growth in vitro or for cell separation. However, Histoplasma yeasts lacking Eng1 function have attenuated virulence in vivo, particularly during the cell-mediated immunity stage. Histoplasma yeasts deficient for Eng1 show increased exposure of cell wall β-glucans, which results in enhanced binding to the Dectin-1 β-glucan receptor. Consistent with this, Eng1-deficient yeasts trigger increased tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) cytokine production from macrophages and dendritic cells. While not responsible for large-scale cell wall structure and function, the secreted Eng1 reduces levels of exposed β-glucans at the yeast cell wall, thereby diminishing potential recognition by Dectin-1 and proinflammatory cytokine production by phagocytes. In α-glucan-producing Histoplasma strains, Eng1 acts in concert with α-glucan to minimize β-glucan exposure: α-glucan provides a masking function by covering the β-glucan-rich cell wall, while Eng1 removes any remaining exposed β-glucans. Thus, Histoplasma Eng1 has evolved a specialized pathogenesis function to remove exposed β-glucans, thereby enhancing the ability of yeasts to escape detection by host phagocytes. PMID:27094334

Reduced tar, nicotine, and carbon monoxide exposure while smoking ultralow- but not low-yield cigarettes

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

Benowitz, N.L.; Jacob, P. III; Yu, L.

An unresolved public health issue is whether some modern cigarettes are less hazardous than other and whether patients who cannot stop smoking should be advised to switch to lower-yield cigarettes. The authors studied tar (estimated by urine mutagenicity), nicotine, and carbon monoxide exposure in habitual smokers switched from their usual brand to high- (15 mg of tar), low- (5 mg of tar), or ultralow-yield (1 mg of tar) cigarettes. There were no differences in exposure comparing high- or low-yield cigarettes, but tar and nicotine exposures were reduced by 49% and 56%, respectively, and carbon monoxide exposure by 36% while smokingmore » ultralow-yield cigarettes. Similarly, in 248 subjects smoking their self-selected brand, nicotine intake, estimated by blood concentrations of its metabolite continine, was 40% lower in those who smoked ultralow but no different in those smoking higher yields of cigarettes. The data indicate that ultralow-yield cigarettes do deliver substantial doses of tar, nicotine, and carbon monoxide, but that exposure are considerably less than for other cigarettes.« less

Pre-packed vacuum bone cement mixing systems. A further step in reducing methylmethacrylate exposure in surgery.

PubMed

Schlegel, Ulf J; Sturm, Michael; Eysel, Peer; Breusch, Steffen J

2010-11-01

Polymethylmethacrylate bone cements are widely used in orthopaedic and trauma surgery as well as in dentistry. The toxic side effects of inhaled methylmethacrylate (MMA) fumes generated during mixing have been well studied. Vacuum cement mixing systems have been shown to reduce the risk of airborne MMA significantly compared to handmixing. In an effort to further reduce MMA exposure, the latest generation of mixing devices are pre-packed with the ingredients and thus allow preparation in nearly closed circuits. Until now, there has been no study proofing the efficacy of those systems in protecting theatre staff from MMA vapours. A pre-packed vacuum mixing system (Optipac®) was compared with two standard systems (Palamix® and Easymix®) regarding MMA emission. The latter systems require loading with the bone cement compounds prior to mixing. Following a standardized procedure, 10 mixes were performed with each system and the emission of MMA vapours in the breathing zone was recorded using photoionization detection over a period of 3 min. The mean MMA exposure was reduced when using the pre-packed system compared to the devices that require filling with the components. The highest emission peaks were recorded during the mixing and preparation steps in all systems. Modern pre-packed vacuum mixing systems further help to reduce the occupational hazards created by bone cement preparation. However, MMA fumes can still be detected using this technique. Although this is an important step in reducing MMA exposure in the operating theatre, further technical effort has to be taken to eliminate the continuous leakage of monomer from the devices while mixing and to minimize necessary manipulation for final delivery.

A randomised controlled trial of a complex intervention to reduce children’s exposure to secondhand smoke in the home

PubMed Central

Thorley, Rebecca; Jones, Laura; Opazo Breton, Magdalena; Cook, Juliette; McNeill, Ann; Britton, John; Coleman, Tim; Lewis, Sarah

2018-01-01

Objectives Exposing children to secondhand tobacco smoke (SHS) causes significant harm and occurs predominantly through smoking by caregivers in the family home. We report a trial of a complex intervention designed to reduce secondhand smoke exposure of children whose primary caregiver feels unable or unwilling to quit smoking. Design An open-label, parallel, randomised controlled trial. Setting Deprived communities in Nottingham City and County, England Participants Caregivers resident in Nottingham City and County in England who were at least 18 years old, the main caregiver of a child aged under 5 years living in their household, and reported that they were smoking tobacco inside their home. Interventions We compared a complex intervention combining personalised feedback on home air quality, behavioural support and nicotine replacement therapy for temporary abstinence with usual care. Main outcomes The primary outcome was change in air quality in the home, measured as average 16–24  hours levels of particulate matter of  < 2.5  µm diameter (PM2.5), between baseline and 12 weeks. Secondary outcomes included changes in maximum PM2.5, proportion of time PM2.5 exceeded WHO recommended levels of maximum exposure of 25  µg/mg3, child salivary cotinine, caregivers’ cigarette consumption, nicotine dependence, determination to stop smoking, quit attempts and quitting altogether during the intervention. Results Arithmetic mean PM2.5 decreased significantly more (by 35.2 %; 95%  CI 12.7% to 51.9 %) in intervention than in usual care households, as did the proportion of time PM2.5 exceeded 25  µg/mg3, child salivary cotinine concentrations, caregivers’ cigarette consumption in the home, nicotine dependence, determination to quit and likelihood of having made a quit attempt. Conclusions By reducing exposure to SHS in the homes of children who live with smokers unable or unwilling to quit, this intervention offers huge potential to reduce children�

Chlorpyrifos exposure in farmers and urban adults: Metabolic characteristic, exposure estimation, and potential effect of oxidative damage.

PubMed

Wang, Lei; Liu, Zhen; Zhang, Junjie; Wu, Yinghong; Sun, Hongwen

2016-08-01

Chlorpyrifos is a widely used organophosphorus pesticide that efficiently protects crops against pests. However, recent studies suggest that severe exposure to chlorpyrifos may present adverse health effects in human. To analyze the exposure level and metabolic characteristics of chlorpyrifos pesticide in urban adults and farmers with/without occupation pesticide contact, the occurrence of urinary chlorpyrifos and methyl chlorpyrifos (CP-me), as well as their metabolite, 3,5,6-trichloro-2-pyridinol (TCPy), was determined in farmers of an agricultural village in China, and in urban adults of a nearby town. The geometric mean (GM) concentrations of TCPy, which is the major marker of chlorpyrifos exposure, were 4.29 and 7.57μg/g-creatinine in urban adults and farmers before pesticide application, respectively. Chlorpyrifos spraying significantly increased the concentrations of urinary TCPy. In the first day after spraying, a GM concentration of 43.7μg/g-creatinine was detected in the urine specimens from farmers, which decreased to 38.1 and 22.8μg/g-creatinine in the second and third day after chlorpyrifos spraying. The ratio of TCPy and its parent compounds, i.e. chlorpyrifos and CP-me, was positively associated with the sum concentration of urinary chlorpyrifos, CP-me, and TCPy, suggesting the increasing metabolic efficiency of chlorpyrifos to TCPy at higher chlorpyrifos exposure levels. To estimate the farmers' occupational exposure to chlorpyrifos pesticide, a new model based on the fitted first-order elimination kinetics of TCPy was established. Occupational chlorpyrifos exposure in a farmer was estimated to be 3.70μg/kg-bw/day (GM), which is an exposure level that is higher than the recommended guideline levels. Significant increase of urinary 8-hydroxydeoxyguanosine (8-OHdG) was observed on the first day after chlorpyrifos spraying, which indicates a potential oxidative damage in farmers. However, urinary 8-OHdG returned to its baseline level within two

Reduced Osmotic Potential Inhibition of Photosynthesis 1

PubMed Central

Berkowitz, Gerald A.; Gibbs, Martin

1983-01-01

The effects of reduced reaction medium osmotic potential (0.67 molar sorbitol as compared to a control treatment with 0.33 molar sorbitol) on the enzymic steps of the photosynthetic carbon reduction cycle were investigated using isolated spinach (Spinacia oleracea L. var Longstanding Bloomsdale) chloroplasts. Reversal of reduced osmotic potential inhibition of photosynthetic rates by a stromal alkalating agent (NH4Cl) was associated with specific steps of the cycle. Low osmotic potential induced stromal acidification was found to be facilitated by osmotically induced chloroplast shrinkage. However, the action of the alkalating agent was found not to be associated with reversal of osmotically induced morphological changes of the stromal compartment. Labeled metabolite analyses indicated that the osmotic stress treatment caused the substrate for fructose 1,6-bisphosphatase (FBPase) to build up in the absence of NH4Cl, and the substrate for phosphoribulokinase to increase in the presence of NH4Cl. These data were interpreted as indicating that the most severe effect of osmotic stress on photosynthesis is at the site of FBPase, and that this inhibition is mediated by osmotically induced stromal acidification. Phosphoribulokinase activity inhibition at the low osmotic potential treatment was apparently less severe and not mediated by stromal acidification. A third site of osmotic inhibition, which was reversed by NH4Cl, and therefore was assumed to be mediated by stromal acidification, was at the step of ribulose 1,5-bisphosphate carboxylase. Additions of NH4Cl also enhanced the activity of the pH-insensitive phase of the photosynthetic carbon reduction cycle, 3-phosphoglyceric acid reduction, at the stress treatment. This effect was thought to be mediated by the removal of the block at FBPase. A model was proposed to outline the relative severity of osmotic stress effects at various sites of the photosynthetic carbon reduction cycle. Images Fig. 1 PMID:16663127

Effectiveness of interventions to reduce exposure to lead through consumer products and drinking water: A systematic review.

PubMed

Pfadenhauer, Lisa Maria; Burns, Jacob; Rohwer, Anke; Rehfuess, Eva Annette

2016-05-01

The objective of this systematic review is to assess the effectiveness of regulatory, environmental and educational interventions for reducing blood lead levels (BLLs) and associated health outcomes in children, pregnant women and the general population. Searches were run in MEDLINE, EMBASE and the Global Health Library up until August 2015. Studies were eligible for inclusion if they assessed the impact of regulatory, environmental or educational interventions, stand-alone or in combination, on BLLs among children, pregnant women or the general population through randomized controlled trials (RCT), controlled before-after (CBA), interrupted time series (ITS), uncontrolled before-after (UBA) or repeated cross-sectional studies. Studies assessing the impact of interventions to reduce exposure to lead in paint or household dust as well as studies concerned exclusively with environmental concentrations of lead were not included. As documented in a detailed protocol, screening, data extraction and quality appraisal were largely undertaken according to Cochrane standards. Harvest plots were used to graphically summarize evidence of effectiveness. The searches yielded 6466 unique records, of which five met our eligibility criteria; two additional eligible studies were identified by experts. We did not find any studies regarding the effectiveness of regulatory, educational or environmental interventions targeting exposure to lead in consumer products. Evidence regarding the effectiveness of interventions in reducing BLLs from exposures through drinking water is limited in both quantity and quality. Stand-alone targeted educational interventions showed no statistically significant reductions in children's BLL (two RCT) when compared to general educational interventions. Likewise, instructing women to reduce or eliminate lead-contaminated drinking water showed no effect on BLL (one RCT). Stand-alone environmental interventions appeared more promising in reducing BLL (three

The epidemiology of animal bite, scratch, and other potential rabies exposures, Louisiana.

PubMed

Balsamo, Gary A; Ratard, Raoult; Claudet, Amanda

2009-01-01

The authors conducted a review of 318 investigative reports of animal exposures recorded from November 2004 through April 2008. These reports were gathered as components of the rabies surveillance program in Louisiana. The reports were recorded by employees of the Louisiana Office of Public Health. Results were summarized and analyzed using the Centers for Disease Control and Prevention's (CDC) EpiInfo statistical software. The most common victims were children, most often exposed to a pet that was familiar. In children victimized by pets, males were much more likely to be involved. Children most often suffered injuries to the head and upper torso. Exposures to bats and skunks characterized the greatest risks for rabies transmission, but potential for exposure to rabies from pet species remained a reality. Pit bull type dogs were most frequently involved in dog bite exposures. Requests for animal rabies testing peak in the summer months. The increased risk to children demonstrates a need for public education, animal control programs, and evaluation of risk from certain breeds. Promotion of rabies vaccine compliance is of utmost importance to public health.

If exposure to aluminium in antiperspirants presents health risks, its content should be reduced.

PubMed

Pineau, Alain; Fauconneau, Bernard; Sappino, André-Pascal; Deloncle, Roger; Guillard, Olivier

2014-04-01

Since aluminium (Al) pervades our environment, the scientific community has for many years raised concerns regarding its safety in humans. Al is present in numerous cosmetics such as antiperspirants, lipsticks and sunscreens. Al chlorohydrate is the active antiperspirant agent in underarm cosmetics and may constitute for Al a key exposure route to the human body and a potential source of damage. An in vitro study has demonstrated that Al from antiperspirant can be absorbed through viable human stripped skin. The potential toxicity of Al has been clearly shown and recent works convincingly argue that Al could be involved in cancerogenic processes. Nowadays, for example, Al is suspected of being involved in breast cancer. Recent work in cells in culture has lent credence to the hypothesis that this metal could accumulate in the mammary gland and selectively interfere with the biological properties of breast epithelial cells, thereby promoting a cascade of alterations reminiscent of the early phases of malignant transformation. In addition, several studies suggest that the presence of Al in human breast could influence metastatic process. As a consequence, given that the toxicity of Al has been widely recognized and that it is not a physiological component in human tissues, reducing the concentration of this metal in antiperspirants is a matter of urgency. Copyright © 2013 Elsevier GmbH. All rights reserved.

Effectiveness of Fluorography versus Cineangiography at Reducing Radiation Exposure During Diagnostic Coronary Angiography

PubMed Central

Shah, Binita; Mai, Xingchen; Tummala, Lakshmi; Kliger, Chad; Bangalore, Sripal; Miller, Louis H.; Sedlis, Steven P.; Feit, Frederick; Liou, Michael; Attubato, Michael; Coppola, John; Slater, James

2014-01-01

Coronary angiography is the gold standard for defining obstructive coronary disease. However, radiation exposure remains an unwanted hazard. Patients referred for coronary angiography with abdominal circumference <45 inches and glomerular filtration rate >60mL/min were randomized to the Fluorography (n=25) or Cineangiography (n=25) group. Patients in the Fluorography group underwent coronary angiography using retrospectively-stored fluorography with repeat injection under cineangiography only when needed for better resolution per operator’s discretion. Patients in the Cineangiography group underwent coronary angiography using routine cineangiography. The primary endpoint was patient radiation exposure measured by radiochromic film. Secondary endpoints included the radiation output measurement of kerma-area product (KAP) and air kerma at the interventional reference point (Ka,r), and operator radiation exposure measured by dosimeter. Patient radiation exposure (158.2mGy [76.5–210.2] vs 272.5mGy [163.3–314.0], p=0.001), KAP (1323μGy m2 [826–1765] vs 3451μGy m2 [2464–4818], p<0.001), and Ka,r (175 mGy [112–252] vs 558 mGy [313–621], p<0.001)was significantly lower in the Fluorography compared with Cineangiography group (42%, 62%, and 69% relative reduction, respectively). Operator radiation exposure trended in the same direction though statistically non-significant (Fluorography 2.35 μGy [1.24–6.30] vs Cineangiography 5.03μGy [2.48–7.80], p=0.059). In conclusion, the use of fluorography in a select group of patients during coronary angiography with repeat injection under cineangiography only when needed was efficacious at reducing patient radiation exposure. PMID:24513469

OVERVIEW OF US EPA RESEARCH ACTIVITIES AIMED AT CHARACTERIZING CHILDREN'S EXPOSURES

EPA Science Inventory

Given the potential vulnerability of children to the effects of environmental exposures, understanding the relationship between children's health outcomes and environmental exposures is an important research need to reduce uncertainty in risk assessment. Over the past 8 year...

Lead exposure reduces sperm quality and DNA integrity in mice.

PubMed

Li, Cuiling; Zhao, Kai; Zhang, Huiping; Liu, Lili; Xiong, Fei; Wang, Kunyu; Chen, Biao

2018-05-01

Toxicity of lead on male reproductive functions has raised wide public concern as environmental lead contamination remains common worldwide. Conflicting and controversial data are available regarding effects of lead on male fertility. More importantly, our knowledge on effects of lead on sperm DNA integrity is significantly limited. Thus, further studies should focus on this issue. In the current study, adult male mice were exposed to a series of lead acetate concentrations in drinking water for six weeks. Following administration, lead levels in blood, testicles, and epididymis were measured, and potential changes in morphology of testis and epididymis due to lead exposure were identified. We also analyzed sperm parameters, including sperm density, viability, motility, and morphology, to evaluate quality of sperm collected from epididymis. Especially, hypothetical influence of lead on sperm DNA integrity was also evaluated by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling, alkaline comet assay, and sperm chromatin structure assay. Lead exposure possibly exerted no effect on growth of mice because these animals acquired similar body weight gain during the experimental period. However, high lead concentrations (0.5% and 1%) in drinking water affected sperm motility and increased percentage of spermatozoa with abnormal morphology. In groups treated with 0.25%, 0.5%, and 1% lead acetate, percentages of sperm cells showing DNA breaks and chromatin structure damage significantly increased. Altogether, lead exposure not only exhibits adverse effects on sperm physiological parameters, but also impairs DNA structure and integrity. These effects may lead to significant decline in male fertility. © 2018 Wiley Periodicals, Inc.

Sperm whales reduce foraging effort during exposure to 1-2 kHz sonar and killer whale sounds.

PubMed

Isojunno, Saana; Cure, Charlotte; Kvadsheim, Petter Helgevold; Lam, Frans-Peter Alexander; Tyack, Peter Lloyd; Wensveen, Paul Jacobus; Miller, Patrick James O'Malley

2016-01-01

The time and energetic costs of behavioral responses to incidental and experimental sonar exposures, as well as control stimuli, were quantified using hidden state analysis of time series of acoustic and movement data recorded by tags (DTAG) attached to 12 sperm whales (Physeter macrocephalus) using suction cups. Behavioral state transition modeling showed that tagged whales switched to a non-foraging, non-resting state during both experimental transmissions of low-frequency active sonar from an approaching vessel (LFAS; 1-2 kHz, source level 214 dB re 1 µPa m, four tag records) and playbacks of potential predator (killer whale, Orcinus orca) sounds broadcast at naturally occurring sound levels as a positive control from a drifting boat (five tag records). Time spent in foraging states and the probability of prey capture attempts were reduced during these two types of exposures with little change in overall locomotion activity, suggesting an effect on energy intake with no immediate compensation. Whales switched to the active non-foraging state over received sound pressure levels of 131-165 dB re 1 µPa during LFAS exposure. In contrast, no changes in foraging behavior were detected in response to experimental negative controls (no-sonar ship approach or noise control playback) or to experimental medium-frequency active sonar exposures (MFAS; 6-7 kHz, source level 199 re 1 µPa m, received sound pressure level [SPL] = 73-158 dB re 1 µPa). Similarly, there was no reduction in foraging effort for three whales exposed to incidental, unidentified 4.7-5.1 kHz sonar signals received at lower levels (SPL = 89-133 dB re 1 µPa). These results demonstrate that similar to predation risk, exposure to sonar can affect functional behaviors, and indicate that increased perception of risk with higher source level or lower frequency may modulate how sperm whales respond to anthropogenic sound.

OSHA Bloodborne Pathogens Standards Exposure Control Plan

NASA Technical Reports Server (NTRS)

Luhrs, Caro Elise; Teitelbaum, Rita

1993-01-01

The Hummer Associates Exposure Control Plan is designed to reduce significant occupational exposure to bloodborne pathogens and infectious materials for Hummer Associates health care personnel. Under universal precautions, all patients and all body fluids are considered potentially infectious for bloodborne pathogens. Medical personnel need not be at increased risk if universal precautions are correctly understood and followed. This program covers all employees who could reasonably anticipate contact with blood or other potentially infectious materials during the performance of their job responsibilities. Although HIV and hepatitis B are mentioned most often, this program applies to all bloodborne diseases. The two main components needed to implement this program are universal precautions and engineering/work practice controls. This program covers all employees who may have occupational exposure to blood or other potentially infectious materials. Other aspects of this program are discussed.

Exposure Potential and Health Impacts of Indium and Gallium, Metals Critical to Emerging Electronics and Energy Technologies.

PubMed

White, Sarah Jane O; Shine, James P

2016-12-01

The rapid growth of new electronics and energy technologies requires the use of rare elements of the periodic table. For many of these elements, little is known about their environmental behavior or human health impacts. This is true for indium and gallium, two technology critical elements. Increased environmental concentrations of both indium and gallium create the potential for increased environmental exposure, though little is known about the extent of this exposure. Evidence is mounting that indium and gallium can have substantial toxicity, including in occupational settings where indium lung disease has been recognized as a potentially fatal disease caused by the inhalation of indium particles. This paper aims to review the basic chemistry, changing environmental concentrations, potential for human exposure, and known health effects of indium and gallium.

Contribution of time-activity pattern and microenvironment to black carbon (BC) inhalation exposure and potential internal dose among elementary school children

NASA Astrophysics Data System (ADS)

Jeong, Hyeran; Park, Donguk

2017-09-01

The aims of this study were to quantify the contributions of activities or microenvironments (MEs) to daily total exposure to and potential dose of black carbon (BC). Daily BC exposures (24-h) were monitored using a micro-aethalometer micoAeth AE51 with forty school-aged children living in an urban area in Korea from August 2015 to January 2016. The children's time-activity patterns and the MEs they visited were investigated by means of a time-activity diary (TAD) and follow-up interviews with the children and their parents. Potential inhaled dose was estimated by multiplying the airborne BC concentrations (μg/m3) we monitored for the time the children spent in a particular ME by the inhalation rate (IR, m3/h) for the time-activity performed. The contribution of activities and MEs to overall daily exposure to and potential dose of BC was quantified. Overall mean daily potential dose was equal to 24.1 ± 10.6 μg/day (range: 6.6-46.3 μg/day). The largest contribution to BC exposure and potential dose (51.9% and 41.7% respectively) occurred in the home thanks to the large amount of time spent there. Transportation was where children received the most intense exposure to (14.8%) and potential dose (20.2%) of BC, while it accounted for 7.6% of daily time. School on weekdays during the semester was responsible for 20.3% of exposure and 22.5% of potential dose. Contribution to BC exposure and potential dose was altered by several time-activity parameters, such as type of day (weekdays vs. weekends; school days vs. holidays), season, and gender. Traveling by motor vehicle and subway showed more elevated exposure or potential dose intensity on weekdays or school days, probably influenced by the increased surrounding traffic volumes on these days compared to on weekends or holidays. This study may be used to prioritize targets for minimizing children's exposure to BC and to indicate outcomes of BC control strategies.

Antenatal steroid exposure in the late preterm period is associated with reduced cord blood neurotrophin-3.

PubMed

Hodyl, Nicolette A; Crawford, Tara M; McKerracher, Lorna; Lawrence, Andrew; Pitcher, Julia B; Stark, Michael J

2016-10-01

Neurotrophins are proteins critically involved in neural growth, survival and differentiation, and therefore important for fetal brain development. Reduced cord blood neurotrophins have been observed in very preterm infants (<32weeks gestation) who subsequently develop brain injury. Antenatal steroid exposure can alter neurotrophin concentrations, yet studies to date have not examined whether this occurs in the late preterm infant (33-36weeks gestation), despite increasing recognition of subtle neurodevelopmental deficits in this population. To assess the impact of antenatal steroids on cord blood neurotrophins in late preterm infants following antenatal steroid exposure. Retrospective analysis. Late preterm infants (33-36weeks; n=119) and term infants (37-41weeks; n=129) born at the Women's and Children's Hospital, Adelaide. Cord blood neurotrophin-3 (NT-3), NT-4, nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) concentrations measured by ELISA. Cord blood NT-4 and NGF were increased at term compared to the late preterm period (p<0.001), while BDNF and NT-3 were not different. In the late preterm period, cord blood NT-3 was reduced when antenatal steroids were administered >24h prior to delivery (p<0.01). This study identified an association between reduced cord blood NT-3 and antenatal steroid exposure in the late preterm period. The reduced NT-3 may be a consequence of steroids inducing neuronal apoptosis, thereby reducing endogenous neuronal NT3 production, or be an action of steroids on other maternal or fetal NT-3 producing cells, which may then affect neuronal growth, differentiation and survival. Regardless of the specific mechanism, a reduction in NT-3 may have long term implications for child neurodevelopment, and emphasizes the ongoing vulnerability of the fetal brain across the full preterm period. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Sources of Potential Lead Exposure Among Pregnant Women in New Mexico

PubMed Central

Rowland, Andrew S.; Young, Bonnie N.; Cano, Sandra; Phelan, Sharon T.; Artyushkova, Kateryna; Rayburn, William F.; Lewis, Johnnye

2013-01-01

The objectives of this study were to ascertain the prevalence and potential sources of lead exposure among pregnant women residing in a socially-disadvantaged immigrant community in Albuquerque, New Mexico. Pregnant women (n = 140) receiving prenatal care through a community clinic participated in a structured interview and screening to measure their blood lead levels (BLLs). Potential sources of lead exposure were ascertained by the CDC and New Mexico Department of Health questionnaires. Self-reported risk factors were examined as predictors of BLLs using multiple linear regression and partial least squares discriminant analysis. Most patients were Spanish-speaking (88.6%), Latina (95%), foreign-born (87.1%), lacked health insurance (86.4%), and had a high school education or lower (84.3%). While risk factors were prevalent in this population, only three women (2.1%) had BLLs ≥3 μg/dL. Results of multivariate analyses demonstrated that pica symptoms in pregnancy, history of elevated BLLs before pregnancy, use of non-commercial pottery, and living in older houses were important predictors of elevated BLLs. Although the prevalence of other risk factors relevant to immigrant communities (i.e., use of traditional/folk remedies and cosmetics, seasonings and food products from Mexico) was high, they were not predictive of elevated BLLs. Clinics providing prenatal care to immigrant Hispanic communities should carefully assess patients’ pica symptoms, use of non-commercial pottery, and a history of elevated BLLs. Moreover, additional efforts need to focus on the development of screening questionnaires which better reflect exposures of concern in this population. PMID:22362260

Sources of potential lead exposure among pregnant women in New Mexico.

PubMed

Bakhireva, Ludmila N; Rowland, Andrew S; Young, Bonnie N; Cano, Sandra; Phelan, Sharon T; Artyushkova, Kateryna; Rayburn, William F; Lewis, Johnnye

2013-01-01

The objectives of this study were to ascertain the prevalence and potential sources of lead exposure among pregnant women residing in a socially-disadvantaged immigrant community in Albuquerque, New Mexico. Pregnant women (n = 140) receiving prenatal care through a community clinic participated in a structured interview and screening to measure their blood lead levels (BLLs). Potential sources of lead exposure were ascertained by the CDC and New Mexico Department of Health questionnaires. Self-reported risk factors were examined as predictors of BLLs using multiple linear regression and partial least squares discriminant analysis. Most patients were Spanish-speaking (88.6%), Latina (95%), foreign-born (87.1%), lacked health insurance (86.4%), and had a high school education or lower (84.3%). While risk factors were prevalent in this population, only three women (2.1%) had BLLs ≥3 μg/dL. Results of multivariate analyses demonstrated that pica symptoms in pregnancy, history of elevated BLLs before pregnancy, use of non-commercial pottery, and living in older houses were important predictors of elevated BLLs. Although the prevalence of other risk factors relevant to immigrant communities (i.e., use of traditional/folk remedies and cosmetics, seasonings and food products from Mexico) was high, they were not predictive of elevated BLLs. Clinics providing prenatal care to immigrant Hispanic communities should carefully assess patients' pica symptoms, use of non-commercial pottery, and a history of elevated BLLs. Moreover, additional efforts need to focus on the development of screening questionnaires which better reflect exposures of concern in this population.

Perceptual Individuation Training (but Not Mere Exposure) Reduces Implicit Racial Bias in Preschool Children

ERIC Educational Resources Information Center

Qian, Miao K.; Quinn, Paul C.; Heyman, Gail D.; Pascalis, Olivier; Fu, Genyue; Lee, Kang

2017-01-01

Two studies with preschool-age children examined the effectiveness of perceptual individuation training at reducing racial bias (Study 1, N = 32; Study 2, N = 56). We found that training preschool-age children to individuate other-race faces resulted in a reduction in implicit racial bias while mere exposure to other-race faces produced no such…

Electrical resistance behavior of oxyfluorinated graphene under oxidizing and reducing gas exposure.

PubMed

Im, Ji Sun; Bae, Tae-Sung; Shin, Eunjeong; Lee, Young-Seak

2014-03-01

The electrical resistance behavior of graphene was studied under oxidizing and reducing gas exposure. The graphene surface was modified via oxyfluorination to obtain a specific surface area and oxygen functional groups. Fluorine radicals provided improved pore structure and introduction of an oxygen functional group. A high-performance gas sensor was obtained based on enlarged target gas adsorption sites and an enhanced electron charge transfer between the target gas and carbon surface via improved pore structure and the introduction of oxygen functional groups, respectively.

Schistosoma mansoni P-glycoprotein levels increase in response to praziquantel exposure and correlate with reduced praziquantel susceptibility.

PubMed

Messerli, Shanta M; Kasinathan, Ravi S; Morgan, William; Spranger, Stefani; Greenberg, Robert M

2009-09-01

One potential physiological target for new antischistosomals is the parasite's system for excretion of wastes and xenobiotics. P-glycoprotein (Pgp), a member of the ATP-binding-cassette superfamily of proteins, is an ATP-dependent efflux pump involved in transport of toxins and xenobiotics from cells. In vertebrates, increased expression of Pgp is associated with multidrug resistance in tumor cells. Pgp may also play a role in drug resistance in helminths. In this report, we examine the relationship between praziquantel (PZQ), the current drug of choice against schistosomiasis, and Pgp expression in Schistosoma mansoni. We show that levels of RNA for SMDR2, a Pgp homolog from S. mansoni, increase transiently in adult male worms following exposure to sub-lethal concentrations (100-500 nM) of PZQ. A corresponding, though delayed, increase in anti-Pgp immunoreactive protein expression occurs in adult males following exposure to PZQ. The level of anti-Pgp immunoreactivity in particular regions of adult worms also increases in response to PZQ. Adult worms from an Egyptian S. mansoni isolate with reduced sensitivity to PZQ express increased levels of SMDR2 RNA and anti-Pgp-immunoreactive protein, perhaps indicating a role for multidrug resistance proteins in development or maintenance of PZQ resistance.

Schistosoma mansoni P-glycoprotein levels increase in response to praziquantel exposure and correlate with reduced praziquantel susceptibility

PubMed Central

Messerli, Shanta M.; Kasinathan, Ravi S.; Morgan, William; Spranger, Stefani; Greenberg, Robert M.

2009-01-01

One potential physiological target for new antischistosomals is the parasite’s system for excretion of wastes and xenobiotics. P-glycoprotein (Pgp), a member of the ATP-binding cassette superfamily of proteins, is an ATP-dependent efflux pump involved in transport of toxins and xenobiotics from cells. In vertebrates, increased expression of Pgp is associated with multidrug resistance in tumor cells. Pgp may also play a role in drug resistance in helminths. In this report, we examine the relationship between praziquantel (PZQ), the current drug of choice against schistosomiasis, and Pgp expression in Schistosoma mansoni. We show that levels of RNA for SMDR2, a Pgp homolog from S. mansoni, increase transiently in adult male worms following exposure to sublethal concentrations (100 – 500 nM) of PZQ. A corresponding, though delayed, increase in anti-Pgp immunoreactive protein expression occurs in adult males following exposure to PZQ. The level of anti-Pgp immunoreactivity in particular regions of adult worms also increases in response to PZQ. Adult worms from an Egyptian S. mansoni isolate with reduced sensitivity to PZQ express increased levels of SMDR2 RNA and anti-Pgp-immunoreactive protein, perhaps indicating a role for multidrug resistance proteins in development or maintenance of PZQ resistance. PMID:19406169

Chronic corticosterone exposure reduces hippocampal glycogen level and induces depression-like behavior in mice.

PubMed

Zhang, Hui-yu; Zhao, Yu-nan; Wang, Zhong-li; Huang, Yu-fang

2015-01-01

Long-term exposure to stress or high glucocorticoid levels leads to depression-like behavior in rodents; however, the cause remains unknown. Increasing evidence shows that astrocytes, the most abundant cells in the central nervous system (CNS), are important to the nervous system. Astrocytes nourish and protect the neurons, and serve as glycogen repositories for the brain. The metabolic process of glycogen, which is closely linked to neuronal activity, can supply sufficient energy substrates for neurons. The research team probed into the effects of chronic corticosterone (CORT) exposure on the glycogen level of astrocytes in the hippocampal tissues of male C57BL/6N mice in this study. The results showed that chronic CORT injection reduced hippocampal neurofilament light protein (NF-L) and synaptophysin (SYP) levels, induced depression-like behavior in male mice, reduced hippocampal glycogen level and glycogen synthase activity, and increased glycogen phosphorylase activity. The results suggested that the reduction of the hippocampal glycogen level may be the mechanism by which chronic CORT treatment damages hippocampal neurons and induces depression-like behavior in male mice.

Exposure to Sunlight Reduces the Risk of Myopia in Rhesus Monkeys

PubMed Central

Wang, Yong; Ding, Hui; Stell, William K.; Liu, Liangping; Li, Saiqun; Liu, Hongshan; Zhong, Xingwu

2015-01-01

might have an effect to reduced hyperopic defocus-induced myopia. Also, the data imply that early life exposure to sunlight may help to maintain normal development of emmetropization later in life, and thus lower the risk of myopic anisometropia in adolescent monkey. PMID:26030845

Gestational exposure to hydroxyprogesterone caproate suppresses reproductive potential in male rats

NASA Astrophysics Data System (ADS)

Pushpalatha, T.; Reddy, P. Ramachandra; Reddy, P. Sreenivasula

2005-08-01

Hydroxyprogesterone caproate was administered to pregnant rats at a dose level of 10 and 25 mg/kg body weight on 1st, 7th and 14th gestational day and the male pups (F1 generation) were allowed to grow for 90 days. The effect of gestational exposure to hydroxyprogesterone caproate on fertility was assessed by breeding F1 male rats with control female rats besides analyzing sperm quality and quantity in F1 male rats. The number of implantation sites and viable fetuses was significantly reduced in females mated with F1 males that were exposed to hydroxyprogesterone caproate during embryonic development. The decrease in sperm function was associated with a decrease in sperm motility, sperm viability and sperm count in F1 rats. The study clearly indicates that in utero exposure to hydroxyprogesterone caproate affects fertility in male rats.

Functional Consequences of Repeated Organophosphate Exposure: Potential Non-Cholinergic Mechanisms

PubMed Central

Terry, A.V.

2012-01-01

The class of chemicals known as the “organophosphates” (OPs) comprises many of the most common agricultural and commercial pesticides that are used worldwide as well as the highly toxic chemical warfare agents. The mechanism of the acute toxicity of OPs in both target and non-target organisms is primarily attributed to inhibitory actions on various forms of cholinesterase leading to excessive peripheral and central cholinergic activity. However, there is now substantial evidence that this canonical (cholinesterase-based) mechanism cannot alone account for the wide-variety of adverse consequences of OP exposure that have been described, especially those associated with repeated exposures to levels that produce no overt signs of acute toxicity. This type of exposure has been associated with prolonged impairments in attention, memory, and other domains of cognition, as well as chronic illnesses where these symptoms are manifested (e.g., Gulf War Illness, Alzheimer’s disease). Due to their highly reactive nature, it is not surprising that OPs might alter the function of a number of enzymes and proteins (in addition to cholinesterase). However, the wide variety of long-term neuropsychiatric symptoms that have been associated with OPs suggests that some basic or fundamental neuronal process was adversely affected during the exposure period. The purpose of this review is to discuss several non-cholinesterase targets of OPs that might affect such fundamental processes and includes cytoskeletal and motor proteins involved in axonal transport, neurotrophins and their receptors, and mitochondria (especially their morphology and movement in axons). Potential therapeutic implications of these OP interactions are also discussed. PMID:22465060

Multi-walled Carbon Nanotubes Reduce Toxicity of Diphenhydramine to Ceriodaphnia dubia in Water and Sediment Exposures.

PubMed

Myer, Mark H; Black, Marsha C

2017-09-01

Multi-walled carbon nanotubes are adsorptive materials that have potential for remediation of organic contaminants in water. Sediment elutriate exposures were undertaken with Ceriodaphnia dubia to compare the toxic effects of diphenhydramine in the presence and absence of sediment and multi-walled carbon nanotubes. In both sediment and solution-only treatments, addition of 0.318 mg/g of carbon nanotubes significantly decreased 48-h mortality relative to control, with a 78.7%-90.1% reduction in treatments with nanotube-amended sediment and 40.7%-53.3% reduction in nanotube-amended water exposures. The greatest degree of relative mortality reduction occurred in sediments containing higher levels of natural organic matter, indicating a potential additive effect.

Industrial production and professional application of manufactured nanomaterials-enabled end products in Dutch industries: potential for exposure.

PubMed

Bekker, Cindy; Brouwer, Derk H; Tielemans, Erik; Pronk, Anjoeka

2013-04-01

In order to make full use of the opportunities while responsibly managing the risks of working with manufactured nanomaterials (MNM), we need to gain insight into the potential level of exposure to MNM in the industry. Therefore, the goal of this study was to obtain an overview of the potential MNM exposure scenarios within relevant industrial sectors, applied exposure controls, and number of workers potentially exposed to MNM in Dutch industrial sectors producing and applying MNM-enabled end products in the Netherlands. A survey was conducted in three phases: (i) identification of MNM-enabled end products; (ii) identification of relevant industrial sectors; and (iii) a tiered telephone survey to estimate actual use of the products among 40 sector organizations/knowledge centres (Tier 1), 350 randomly selected companies (Tier 2), and 110 actively searched companies (Tier 3). The most dominant industrial sectors producing or applying MNM-enabled end products (market penetration >5%) are shoe repair shops, automotive, construction, paint, metal, and textile cleaning industry. In the majority of the companies (76%), potential risks related to working with MNM are not a specific point of interest. The total number of workers potentially exposed to MNM during the production or application of MNM-enabled end products was estimated at approximately 3000 workers in the Netherlands. The results of this study will serve as a basis for in-depth exposure and health surveys that are currently planned in the Netherlands. In addition, the results can be used to identify the most relevant sectors for policy makers and future studies focussing on evaluating the risks of occupational exposure to MNM.

Potential impact of clinical use of noninvasive FFRCT on radiation dose exposure and downstream clinical event rate.

PubMed

Bilbey, Nicolas; Blanke, Philipp; Naoum, Christopher; Arepalli, Chesnel Dey; Norgaard, Bjarne Linde; Leipsic, Jonathon

2016-01-01

This study aims to determine the potential impact of introducing noninvasive fractional flow reserve based on coronary computed tomography angiography (CTA) into clinical practice, with respect to radiation dose exposure and downstream event rate. We modeled a population of 1000 stable, symptomatic patients with suspected coronary artery disease, using the disease prevalence from the CONFIRM registry to estimate the pretest likelihood. Four potential clinical pathways were modeled based on the first noninvasive diagnostic test performed: (1) dobutamine echo; (2) single-photon emission computerized tomography (SPECT); (3) coronary CTA; and (4) CTA+FFRCT and leading to possible invasive coronary angiography. The posttest likelihood of testing positive/negative by each test was based on the presenting disease burden and diagnostic accuracy of each test. The dobutamine echo pathway resulted in the lowest radiation dose of 5.4 mSv, with 4.0 mSv from angiography and 1.4 mSv from percutaneous coronary intervention (PCI). The highest dose was with SPECT, with 26.5 mSv. The coronary computed tomography angiography (cCTA) pathway demonstrated a dose of 14.2 mSv, 3.7 mSv from cCTA, 7.7 mSv from angiography, and 2.8 mSv from PCI. The CTA+FFRCT pathway exhibited a radiation dose of 9.7 mSv, 3.7 mSv for cCTA, 4.2 mSv for angiography, and 1.8 mSv for PCI. Radiation dose exposure for CTA+FFRCT was lower than for SPECT (P<.001). The CTA+FFRCT pathway resulted in the lowest projected death/myocardial infarction rate at 1 year (2.44%) while the dobutamine stress pathway had the highest 1-year event rate (2.84%). Our analysis suggests that integrating FFRCT into the CTA clinical pathway may result in reduced cumulative radiation exposure, while promoting favorable clinical outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Daily exposure to either a high- or low-energy-dense snack food reduces its reinforcing value in adolescents.

PubMed

Temple, Jennifer L; Van der Kloet, Erika; Atkins, Amanda M; Crandall, Amanda K; Ziegler, Amanda M

2017-02-01

To examine the impact of daily exposure to a low-energy-dense (LED) or a high-energy-dense (HED) snack food on its reinforcing value (RRV) in adolescents with healthy weight, overweight, or obesity. A parallel-group, randomized trial was used to assess RRV of LED or HED snack food at baseline and again after exposure to that snack food daily for 2 weeks in 77 adolescents, aged 13 to 17 years. Information on eating-related subject characteristics was also collected at baseline. After 2 weeks of daily exposure, the RRV of the snack foods was significantly reduced in all participants, regardless of energy density or participant weight status. Among individuals who were high in dietary restraint only, those randomized to LED food found their snack food less reinforcing at baseline than those who were randomized to HED food. Baseline eating-related variables also differed as a function of weight status. Daily exposure to snack food in adolescents reduces the RRV of that food regardless of snack food energy density or weight status of the adolescent. This finding differs from adults, suggesting that increases in RRV of HED food after repeated exposure may develop after adolescence. © 2017 The Obesity Society.

EARLY BIOMARKERS OF ACUTE RESPIRATORY ALLERGEN EXPOSURE

EPA Science Inventory

Rationale: Allergic asthma prevalence has been increasing in Western societies for several decades. Identification of potential allergens facilitates reduction in exposure and may reduce the risk of asthma development. Predictive models for recognition of sensitizers require th...

An Intervention to Reduce Residential Insecticide Exposure during Pregnancy among an Inner-City Cohort

PubMed Central

Williams, Megan K.; Barr, Dana B.; Camann, David E.; Cruz, Linda A.; Carlton, Elizabeth J.; Borjas, Mejico; Reyes, Andria; Evans, Dave; Kinney, Patrick L.; Whitehead, Ralph D.; Perera, Frederica P.; Matsoanne, Stephen; Whyatt, Robin M.

2006-01-01

Background We previously reported widespread insecticide exposure during pregnancy among inner-city women from New York City. Here we report on a pilot intervention using integrated pest management (IPM) to reduce pest infestations and residential insecticide exposures among pregnant New York City African-American and Latina women (25 intervention and 27 control homes). Methods The IPM consisted of professional cleaning, sealing of pest entry points, application of low-toxicity pesticides, and education. Cockroach infestation levels and 2-week integrated indoor air samples were collected at baseline and one month postintervention. The insecticides detected in the indoor air samples were also measured in maternal and umbilical cord blood collected at delivery. Results Cockroach infestations decreased significantly (p = 0.016) after the intervention among intervention cases but not control households. Among the intervention group, levels of piperonyl butoxide (a pyrethroid synergist) were significantly lower in indoor air samples after the intervention (p = 0.016). Insecticides were detected in maternal blood samples collected at delivery from controls but not from the intervention group. The difference was significant for trans-permethrin (p = 0.008) and of borderline significance (p = 0.1) for cis-permethrin and 2-isopropoxyphenol (a propoxur metabolite). Conclusion To our knowledge, this is the first study to use biologic dosimeters of prenatal pesticide exposure for assessing effectiveness of IPM. These pilot data suggest that IPM is an effective strategy for reducing pest infestation levels and the internal dose of insecticides during pregnancy. PMID:17107853

Aflatoxin Exposure During Pregnancy, Maternal Anemia, and Adverse Birth Outcomes

PubMed Central

Smith, Laura E.; Prendergast, Andrew J.; Turner, Paul C.; Humphrey, Jean H.; Stoltzfus, Rebecca J.

2017-01-01

Pregnant women and their developing fetuses are vulnerable to multiple environmental insults, including exposure to aflatoxin, a mycotoxin that may contaminate as much as 25% of the world food supply. We reviewed and integrated findings from studies of aflatoxin exposure during pregnancy and evaluated potential links to adverse pregnancy outcomes. We identified 27 studies (10 human cross-sectional studies and 17 animal studies) assessing the relationship between aflatoxin exposure and adverse birth outcomes or anemia. Findings suggest that aflatoxin exposure during pregnancy may impair fetal growth. Only one human study investigated aflatoxin exposure and prematurity, and no studies investigated its relationship with pregnancy loss, but animal studies suggest aflatoxin exposure may increase risk for prematurity and pregnancy loss. The fetus could be affected by maternal aflatoxin exposure through direct toxicity as well as indirect toxicity, via maternal systemic inflammation, impaired placental growth, or elevation of placental cytokines. The cytotoxic and systemic effects of aflatoxin could plausibly mediate maternal anemia, intrauterine growth restriction, fetal loss, and preterm birth. Given the widespread exposure to this toxin in developing countries, longitudinal studies in pregnant women are needed to provide stronger evidence for the role of aflatoxin in adverse pregnancy outcomes, and to explore biological mechanisms. Potential pathways for intervention to reduce aflatoxin exposure are urgently needed, and this might reduce the global burden of stillbirth, preterm birth, and low birthweight. PMID:28500823

Aflatoxin Exposure During Pregnancy, Maternal Anemia, and Adverse Birth Outcomes.

PubMed

Smith, Laura E; Prendergast, Andrew J; Turner, Paul C; Humphrey, Jean H; Stoltzfus, Rebecca J

2017-04-01

AbstractPregnant women and their developing fetuses are vulnerable to multiple environmental insults, including exposure to aflatoxin, a mycotoxin that may contaminate as much as 25% of the world food supply. We reviewed and integrated findings from studies of aflatoxin exposure during pregnancy and evaluated potential links to adverse pregnancy outcomes. We identified 27 studies (10 human cross-sectional studies and 17 animal studies) assessing the relationship between aflatoxin exposure and adverse birth outcomes or anemia. Findings suggest that aflatoxin exposure during pregnancy may impair fetal growth. Only one human study investigated aflatoxin exposure and prematurity, and no studies investigated its relationship with pregnancy loss, but animal studies suggest aflatoxin exposure may increase risk for prematurity and pregnancy loss. The fetus could be affected by maternal aflatoxin exposure through direct toxicity as well as indirect toxicity, via maternal systemic inflammation, impaired placental growth, or elevation of placental cytokines. The cytotoxic and systemic effects of aflatoxin could plausibly mediate maternal anemia, intrauterine growth restriction, fetal loss, and preterm birth. Given the widespread exposure to this toxin in developing countries, longitudinal studies in pregnant women are needed to provide stronger evidence for the role of aflatoxin in adverse pregnancy outcomes, and to explore biological mechanisms. Potential pathways for intervention to reduce aflatoxin exposure are urgently needed, and this might reduce the global burden of stillbirth, preterm birth, and low birthweight.

Comprehensive Coach Education Reduces Head Impact Exposure in American Youth Football.

PubMed

Kerr, Zachary Y; Yeargin, Susan W; Valovich McLeod, Tamara C; Mensch, James; Hayden, Ross; Dompier, Thomas P

2015-10-01

Despite little evidence that defines a threshold of head impact exposure or that participation in youth sports leads to long-term cognitive impairments, it is prudent to identify methods of reducing the frequency of head impacts. To compare the mean number of head impacts between youth football players in practice and games between leagues that implemented the Heads Up Football (HUF) educational program and those that did not (NHUF). Cohort study; Level of evidence, 2. During the 2014 season, head impact exposure was measured using xPatch accelerometers from 70 youth football players aged 8 to 15 years from 5 leagues. Data were collected during both games and practices. The NHUF group comprised 32 players from 8 teams within 3 leagues. The HUF group comprised 38 players from 7 teams within 2 leagues. Independent-sample t tests evaluated differences in head impact exposure across groups (ie, HUF and NHUF). Players (mean ± SD: age, 11.7 ± 1.4 years; height, 152.2 ± 10.5 cm; weight, 51.6 ± 9.6 kg) experienced a total of 7478 impacts over 10g, of which 4250 (56.8%) and 3228 (43.2%) occurred in practices and games, respectively. The majority of impacts occurred within the NHUF group (62.0%), followed by the HUF group (38.0%). With a 10g impact threshold, the mean number of impacts during practice per individual event was lower in the HUF group (mean ± SD, 5.6 ± 2.9) than in the NHUF group (mean ± SD, 8.9 ± 3.1; difference, 3.4; 95% CI, 2.9-3.9). This difference was attenuated when the threshold was changed to 20g but remained significant (difference, 1.0; 95% CI, 0.7-1.3). At both the 10g and 20g impact thresholds, no differences were found in games. Players who participated in HUF leagues accumulated fewer head impacts per practice at both the 10g and 20g thresholds. Youth football leagues should consider the HUF educational program, while exploring additional interventions, to help reduce the number of head impacts in players.

Comprehensive Coach Education Reduces Head Impact Exposure in American Youth Football

PubMed Central

Kerr, Zachary Y.; Yeargin, Susan W.; Valovich McLeod, Tamara C.; Mensch, James; Hayden, Ross; Dompier, Thomas P.

2015-01-01

Background: Despite little evidence that defines a threshold of head impact exposure or that participation in youth sports leads to long-term cognitive impairments, it is prudent to identify methods of reducing the frequency of head impacts. Purpose: To compare the mean number of head impacts between youth football players in practice and games between leagues that implemented the Heads Up Football (HUF) educational program and those that did not (NHUF). Study Design: Cohort study; Level of evidence, 2. Methods: During the 2014 season, head impact exposure was measured using xPatch accelerometers from 70 youth football players aged 8 to 15 years from 5 leagues. Data were collected during both games and practices. The NHUF group comprised 32 players from 8 teams within 3 leagues. The HUF group comprised 38 players from 7 teams within 2 leagues. Independent-sample t tests evaluated differences in head impact exposure across groups (ie, HUF and NHUF). Results: Players (mean ± SD: age, 11.7 ± 1.4 years; height, 152.2 ± 10.5 cm; weight, 51.6 ± 9.6 kg) experienced a total of 7478 impacts over 10g, of which 4250 (56.8%) and 3228 (43.2%) occurred in practices and games, respectively. The majority of impacts occurred within the NHUF group (62.0%), followed by the HUF group (38.0%). With a 10g impact threshold, the mean number of impacts during practice per individual event was lower in the HUF group (mean ± SD, 5.6 ± 2.9) than in the NHUF group (mean ± SD, 8.9 ± 3.1; difference, 3.4; 95% CI, 2.9-3.9). This difference was attenuated when the threshold was changed to 20g but remained significant (difference, 1.0; 95% CI, 0.7-1.3). At both the 10g and 20g impact thresholds, no differences were found in games. Conclusion: Players who participated in HUF leagues accumulated fewer head impacts per practice at both the 10g and 20g thresholds. Youth football leagues should consider the HUF educational program, while exploring additional interventions, to help reduce the

Impact of the California lead ammunition ban on reducing lead exposure in golden eagles and turkey vultures.

PubMed

Kelly, Terra R; Bloom, Peter H; Torres, Steve G; Hernandez, Yvette Z; Poppenga, Robert H; Boyce, Walter M; Johnson, Christine K

2011-04-06

Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites.

Impact of the California Lead Ammunition Ban on Reducing Lead Exposure in Golden Eagles and Turkey Vultures

PubMed Central

Kelly, Terra R.; Bloom, Peter H.; Torres, Steve G.; Hernandez, Yvette Z.; Poppenga, Robert H.; Boyce, Walter M.; Johnson, Christine K.

2011-01-01

Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites. PMID:21494329

Effects of long-time elevated temperature exposures on hot-isostatically-pressed power-metallurgy Udimet 700 alloys with reduced cobalt contents

NASA Technical Reports Server (NTRS)

Hart, F. H.

1984-01-01

Because almost the entire U.S. consumption of cobalt depends on imports, this metal has been designated "strategic'. The role and effectiveness of cobalt is being evaluated in commercial nickel-base superalloys. Udiment 700 type alloys in which the cobalt content was reduced from the normal 17% down to 12.7%, 8.5%, 4.3%, and 0% were prepared by standard powder metallurgy techniques and hot isostatically pressed into billets. Mechanical testing and microstructural investigations were performed. The mechanical properties of alloys with reduced cobalt contents which were heat-treated identically were equal or better than those of the standard alloy, except that creep rates tended to increase as cobalt was reduced. The effects of long time exposures at 760 C on mechanical properties and at 760 C and 845 C on microstructures were determined. Decreased tensile properties and shorter rupture lives with increased creep rates were observed in alloy modifications. The exposures caused gamma prime particle coarsening and formation of sigma phase in the alloys with higher cobalt contents. Exposure at 845 C also reduced the amount of MC carbides.

Effectiveness of an occupational health intervention program to reduce whole body vibration exposure: an evaluation study with a controlled pretest-post-test design.

PubMed

Tiemessen, Ivo J H; Hulshof, Carel T J; Frings-Dresen, Monique H W

2009-12-01

An effective intervention program aiming to reduce whole body vibration (WBV) exposure at work will reduce the number of low back complaints in the near future. An evaluation study with a controlled pretest-post-test design. Nine companies and 126 drivers were included in the study. Cluster randomization on company level divided the drivers and their employers in an intervention group and a "care-as-usual" group. At baseline (T0) and intervention program was implemented and evaluated after 7 months (T1). The main outcome measure was WBV exposure. Process measures included knowledge, attitude, and (intended) behavior towards reduction of WBV exposure for the drivers and knowledge and WBV policy for the employers. At T1, no significant reduction was found in WBV exposure within both groups compared with T0. Probably due to poor to moderate compliance, the intervention program was not effective in reducing the WBV exposure on group level but small reductions in WBV exposure are possible when intervention compliance is high. Copyright 2009 Wiley-Liss, Inc.

Reducing the volume, exposure and negative impacts of advertising for foods high in fat, sugar and salt to children: A systematic review of the evidence from statutory and self-regulatory actions and educational measures.

PubMed

Chambers, Stephanie A; Freeman, Ruth; Anderson, Annie S; MacGillivray, Steve

2015-06-01

To identify and review evidence on 1) the effectiveness of statutory and self-regulatory actions to reduce the volume, exposure or wider impact of advertising for foods high in fat, sugar and salt (HFSS) to children, and 2) the role of educational measures. A systematic review of three databases (Medline, CINAHL and PsycINFO) and grey literature was carried out. Relevant evidence included studies evaluating advertising bans and restrictions, advertising literacy programmes and parental communication styles. Relevant media included TV, internet, radio, magazines and newspaper advertising. No studies were excluded based on language or publication date. Forty-seven publications were included: 19 provided evidence for the results of statutory regulation, 25 for self-regulation, and six for educational approaches. Outcome measures varied in approach, quality and results. Findings suggested statutory regulation could reduce the volume of and children's exposure to advertising for foods HFSS, and had potential to impact more widely. Self-regulatory approaches showed varied results in reducing children's exposure. There was some limited support for educational measures. Consistency in measures from evaluations over time would assist the development and interpretation of the evidence base on successful actions and measures to reduce the volume, exposure and impact of advertising for foods HFSS to children. Copyright © 2015 Elsevier Inc. All rights reserved.

AN OBSERVATIONAL STUDY ON THE POTENTIAL EXPOSURES OF 111 PRESCHOOL CHILDREN TO PHTHALATES IN THEIR EVERYDAY ENVIRONMENTS

EPA Science Inventory

The purpose of this work was to identify potential sources and routes of preschool children exposures to two phthalate diesters used in household and personal care products and building materials. Exposure and biomonitoring data was reviewed. The abstract included the preliminary...

Using Behavior Change to Reduce Child Lead Exposure in Resource-Poor Settings: A Formative Study

ERIC Educational Resources Information Center

Feit, M. N.; Mathee, A.; Harpham, T.; Barnes, B. R.

2014-01-01

The objective of this formative research was to explore the acceptability and feasibility of changing housekeeping behaviors as a low-cost approach that may reduce childhood lead exposure in Johannesburg, South Africa. Using the Trials of Improved Practices (TIPs) methodology, modified housekeeping behaviors were negotiated with participants who…

External radiation dose and cancer mortality among French nuclear workers: considering potential confounding by internal radiation exposure.

PubMed

Fournier, L; Laurent, O; Samson, E; Caër-Lorho, S; Laroche, P; Le Guen, B; Laurier, D; Leuraud, K

2016-11-01

French nuclear workers have detailed records of their occupational exposure to external radiation that have been used to examine associations with subsequent cancer mortality. However, some workers were also exposed to internal contamination by radionuclides. This study aims to assess the potential for bias due to confounding by internal contamination of estimates of associations between external radiation exposure and cancer mortality. A cohort of 59,004 workers employed for at least 1 year between 1950 and 1994 by CEA (Commissariat à l'Energie Atomique), AREVA NC, or EDF (Electricité de France) and badge-monitored for external radiation exposure were followed through 2004 to assess vital status and cause of death. A flag based on a workstation-exposure matrix defined four levels of potential for internal contamination. Standardized mortality ratios were assessed for each level of the internal contamination indicator. Poisson regression was used to quantify associations between external radiation exposure and cancer mortality, adjusting for potential internal contamination. For solid cancer, the mortality deficit tended to decrease as the levels of potential for internal contamination increased. For solid cancer and leukemia excluding chronic lymphocytic leukemia, adjusting the dose-response analysis on the internal contamination indicator did not markedly change the excess relative risk per Sievert of external radiation dose. This study suggests that in this cohort, neglecting information on internal dosimetry while studying the association between external dose and cancer mortality does not generate a substantial bias. To investigate more specifically the health effects of internal contamination, an effort is underway to estimate organ doses due to internal contamination.

Deer carcass decomposition and potential scavenger exposure to chronic wasting disease

USGS Publications Warehouse

Jennelle, C.S.; Samuel, M.D.; Nolden, C.A.; Berkley, E.A.

2009-01-01

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy afflicting the Cervidae family in North America, causing neurodegeneration and ultimately death. Although there are no reports of natural cross-species transmission of CWD to noncervids, infected deer carcasses pose a potential risk of CWD exposure for other animals. We placed 40 disease-free white-tailed deer (Odocoileus virginianus) carcasses and 10 gut piles in the CWD-affected area of Wisconsin (USA) from September to April in 2003 through 2005. We used photos from remotely operated cameras to characterize scavenger visitation and relative activity. To evaluate factors driving the rate of carcass removal (decomposition), we used KaplanMeier survival analysis and a generalized linear mixed model. We recorded 14 species of scavenging mammals (6 visiting species) and 14 species of scavenging birds (8 visiting species). Prominent scavengers included American crows (Corvus brachyrhynchos), raccoons (Procyon lotor), and Virginia opossums (Didelphis virginiana). We found no evidence that deer consumed conspecific remains, although they visited gut piles more often than carcasses relative to temporal availability in the environment. Domestic dogs, cats, and cows either scavenged or visited carcass sites, which could lead to human exposure to CWD. Deer carcasses persisted for 18 days to 101 days depending on the season and year, whereas gut piles lasted for 3 days. Habitat did not influence carcass decomposition, but mammalian and avian scavenger activity and higher temperatures were positively associated with faster removal. Infected deer carcasses or gut piles can serve as potential sources of CWD prions to a variety of scavengers. In areas where surveillance for CWD exposure is practical, management agencies should consider strategies for testing primary scavengers of deer carcass material.

Lung cancer deaths from indoor radon and the cost effectiveness and potential of policies to reduce them.

PubMed

Gray, Alastair; Read, Simon; McGale, Paul; Darby, Sarah

2009-01-06

To determine the number of deaths from lung cancer related to radon in the home and to explore the cost effectiveness of alternative policies to control indoor radon and their potential to reduce lung cancer mortality. Cost effectiveness analysis. United Kingdom. Epidemiological data on risks from indoor radon and from smoking, vital statistics on deaths from lung cancer, survey information on effectiveness and costs of radon prevention and remediation. Estimated number of deaths from lung cancer related to indoor radon, lifetime risks of death from lung cancer before and after various potential interventions to control radon, the cost per quality adjusted life year (QALY) gained from different policies for control of radon, and the potential of those policies to reduce lung cancer mortality. The mean radon concentration in UK homes is 21 becquerels per cubic metre (Bq/m(3)). Each year around 1100 deaths from lung cancer (3.3% of all deaths from lung cancer) are related to radon in the home. Over 85% of these arise from radon concentrations below 100 Bq/m(3) and most are caused jointly by radon and active smoking. Current policy requiring basic measures to prevent radon in new homes in selected areas is highly cost effective, and such measures would remain cost effective if extended to the entire UK, with a cost per QALY gained of pound11,400 ( euro12 200; $16,913). Current policy identifying and remediating existing homes with high radon levels is, however, neither cost effective (cost per QALY gained pound36,800) nor effective in reducing lung cancer mortality. Policies requiring basic preventive measures against radon in all new homes throughout the UK would be cost effective and could complement existing policies to reduce smoking. Policies involving remedial work on existing homes with high radon levels cannot prevent most radon related deaths, as these are caused by moderate exposure in many homes. These conclusions are likely to apply to most developed

Running Reduces Uncontrollable Stress-Evoked Serotonin and Potentiates Stress-Evoked Dopamine Concentrations in the Rat Dorsal Striatum

PubMed Central

Clark, Peter J.; Amat, Jose; McConnell, Sara O.; Ghasem, Parsa R.; Greenwood, Benjamin N.; Maier, Steven F.; Fleshner, Monika

2015-01-01

Accumulating evidence from both the human and animal literature indicates that exercise reduces the negative consequences of stress. The neurobiological etiology for this stress protection, however, is not completely understood. Our lab reported that voluntary wheel running protects rats from expressing depression-like instrumental learning deficits on the shuttle box escape task after exposure to unpredictable and inescapable tail shocks (uncontrollable stress). Impaired escape behavior is a result of stress-sensitized serotonin (5-HT) neuron activity in the dorsal raphe (DRN) and subsequent excessive release of 5-HT into the dorsal striatum following exposure to a comparatively mild stressor. However, the possible mechanisms by which exercise prevents stress-induced escape deficits are not well characterized. The purpose of this experiment was to test the hypothesis that exercise blunts the stress-evoked release of 5-HT in the dorsal striatum. Changes to dopamine (DA) levels were also examined, since striatal DA signaling is critical for instrumental learning and can be influenced by changes to 5-HT activity. Adult male F344 rats, housed with or without running wheels for 6 weeks, were either exposed to tail shock or remained undisturbed in laboratory cages. Twenty-four hours later, microdialysis was performed in the medial (DMS) and lateral (DLS) dorsal striatum to collect extracellular 5-HT and DA before, during, and following 2 mild foot shocks. We report wheel running prevents foot shock-induced elevation of extracellular 5-HT and potentiates DA concentrations in both the DMS and DLS approximately 24 h following exposure to uncontrollable stress. These data may provide a possible mechanism by which exercise prevents depression-like instrumental learning deficits following exposure to acute stress. PMID:26555633

Derivation of safe health-based exposure limits for potential consumer exposure to styrene migrating into food from food containers.

PubMed

Gelbke, Heinz-Peter; Banton, Marcy; Faes, Eric; Leibold, Edgar; Pemberton, Mark; Duhayon, Sophie

2014-02-01

Residual styrene present in polystyrene food packaging may migrate into food at low levels. To assure safe use, safe exposure levels are derived for consumers potentially exposed via food using No/Low Adverse Effect Levels from animal and human studies and assessment factors proposed by European organisations (EFSA, ECHA, ECETOC). Ototoxicity and developmental toxicity in rats and human ototoxicity and effects on colour discrimination have been identified as the most relevant toxicological properties for styrene health assessments. Safe exposure levels derived from animal studies with assessment factors of EFSA and ECHA were expectedly much lower than those using the ECETOC approach. Comparable safe exposure levels were obtained from human data with all sets of assessment factors while ototoxicity in rats led to major differences. The safe exposure levels finally selected based on criteria of science and health protection converged to the range of 90-120 mg/person/d. Assuming a consumption of 1 kg food/d for an adult, this translates to 90 mg styrene migration into 1 kg food as safe for consumers. This assessment supports a health based Specific Migration Limit of 90 ppm, a value somewhat higher than the current overall migration limit of 60 ppm in the European Union. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

School Occupational Exposure to Bloodborne Pathogens. A Report To Provide Information.

ERIC Educational Resources Information Center

Iowa State Dept. of Education, Des Moines. Bureau of Special Education.

This report discusses a federally mandated standard concerning establishment of a program to reduce exposure to blood and other potentially infectious materials (OPIM) in Iowa schools and education agencies. The standard includes the following components: introduction, scope and application, definitions, exposure control, methods of compliance,…

Agmatine Reduces Balance Deficits In a Rat Model Of Third Trimester Binge-Like Ethanol Exposure

PubMed Central

Lewis, B.; Wellman, K.A.; Barron, S.

2007-01-01

This study examined the effects of binge-like ethanol (ETOH) exposure in neonatal rats on a cerebellar-mediated balance task, and the ability of agmatine, an n-methyl-d-aspartate receptor (NMDAR) modulator, to reverse such effects. Five neonatal treatments groups were used, including ETOH (6.0 g/kg/day), AG (20 mg/kg), ETOH plus AG (6.0 g/kg/day and 20 mg/kg), a maltose control, and a non-treated control. Ethanol was administered via oral intubation twice daily for eight days, (AG was administered with the last ETOH intubation only). Two exposure periods were used; PND 1–8 or PND 8–15. On PND 31–33, balance performance on a single dowel was tested. Treatment with AG during withdrawal in ETOH exposed animals improved performance relative to ETOH alone among the PND 1–8 exposure period. ETOH exposure during the 2nd postnatal week did not impair balance. These findings provide further support that exposure to ETOH during critical developmental periods can impair performance on a cerebellar-dependent balance task. Of perhaps greater significance, co-administration of agmatine reduced these deficits suggesting that NMDA modulation via polyamine blockade may provide a novel approach to attenuating damage associated with binge-like ETOH consumption. PMID:17714770

Attributable risk and potential impact of interventions to reduce household air pollution associated with under-five mortality in South Asia.

PubMed

Naz, Sabrina; Page, Andrew; Agho, Kingsley Emwinyore

2018-01-01

Solid fuel use is the major source of household air pollution (HAP) and accounts for a substantial burden of morbidity and mortality in low and middle income countries. To evaluate and compare childhood mortality attributable to HAP in four South Asian countries. A series of Demographic and Health Survey (DHS) datasets for Bangladesh, India, Nepal and Pakistan were used for analysis. Estimates of relative risk and exposure prevalence relating to use of cooking fuel and under-five mortality were used to calculate population attributable fractions (PAFs) for each country. Potential impact fractions (PIFs) were also calculated assessing theoretical scenarios based on published interventions aiming to reduce exposure prevalence. There are an increased risk of under-five mortality in those exposed to cooking fuel compared to those not exposed in the four South Asian countries (OR = 1.30, 95% CI = 1.07-1.57, P  = 0.007). Combined PAF estimates for South Asia found that 66% (95% CI: 43.1-81.5%) of the 13,290 estimated cases of under-five mortality was attributable to HAP. Joint PIF estimates (assuming achievable reductions in HAP reported in intervention studies conducted in South Asia) indicates 47% of neonatal and 43% of under-five mortality cases associated with HAP could be avoidable in the four South Asian countries studied. Elimination of exposure to use of cooking fuel in the household targeting valuable intervention strategies (such as cooking in separate kitchen, improved cook stoves) could reduce substantially under-five mortality in South Asian countries.

Vinclozolin Exposure in Utero Induces Postpubertal Prostatitis and Reduces Sperm Production via a Reversible Hormone-Regulated Mechanism

PubMed Central

Cowin, Prue A.; Gold, Elspeth; Aleksova, Jasna; O'Bryan, Moira K.; Foster, Paul M. D.; Scott, Hamish S.; Risbridger, Gail P.

2010-01-01

Vinclozolin is an endocrine-disrupting chemical (EDC) that binds with high affinity to the androgen receptor (AR) and blocks the action of gonadal hormones on male reproductive organs. An alternative mechanism of action of Vinclozolin involves transgenerational effects on the male reproductive tract. We previously reported in utero Vinclozolin exposure-induced prostatitis (prostate inflammation) in postpubertal rats concurrent with down-regulation of AR and increased nuclear factor-κB activation. We postulated the male reproductive abnormalities induced by in utero Vinclozolin exposure could be reversed by testosterone supplementation, in contrast to the permanent modifications involving DNA methyltransferases (Dnmts) described by others. To test this hypothesis, we administered high-dose testosterone at puberty to Vinclozolin-treated rats and determined the effect on anogenital distance (AGD); testicular germ cell apoptosis, concentration of elongated spermatids, and the onset of prostatitis. Concurrently we examined Dnmt1, −3A, −3B, and −3L mRNA expression. Consistent with previous reports, in utero exposure to Vinclozolin significantly reduced AGD, increased testicular germ cell apoptosis 3-fold, reduced elongated spermatid number by 40%, and induced postpubertal prostatitis in 100% of exposed males. Administration of high-dose testosterone (25 mg/kg) at puberty normalized AGD, reduced germ cell apoptosis, and restored elongated spermatid number. Testosterone restored AR and nuclear factor-κB expression in the prostate and abolished Vinclozolin-induced prostatitis. Altered Dnmt expression was evident with in utero Vinclozolin exposure and was not normalized after testosterone treatment. These data demonstrate in utero Vinclozolin-induced male reproductive tract abnormalities are AR mediated and reversible and involve a mechanism independent of Dnmt expression. PMID:20056826

Vinclozolin exposure in utero induces postpubertal prostatitis and reduces sperm production via a reversible hormone-regulated mechanism.

PubMed

Cowin, Prue A; Gold, Elspeth; Aleksova, Jasna; O'Bryan, Moira K; Foster, Paul M D; Scott, Hamish S; Risbridger, Gail P

2010-02-01

Vinclozolin is an endocrine-disrupting chemical (EDC) that binds with high affinity to the androgen receptor (AR) and blocks the action of gonadal hormones on male reproductive organs. An alternative mechanism of action of Vinclozolin involves transgenerational effects on the male reproductive tract. We previously reported in utero Vinclozolin exposure-induced prostatitis (prostate inflammation) in postpubertal rats concurrent with down-regulation of AR and increased nuclear factor-kappaB activation. We postulated the male reproductive abnormalities induced by in utero Vinclozolin exposure could be reversed by testosterone supplementation, in contrast to the permanent modifications involving DNA methyltransferases (Dnmts) described by others. To test this hypothesis, we administered high-dose testosterone at puberty to Vinclozolin-treated rats and determined the effect on anogenital distance (AGD); testicular germ cell apoptosis, concentration of elongated spermatids, and the onset of prostatitis. Concurrently we examined Dnmt1, -3A, -3B, and -3L mRNA expression. Consistent with previous reports, in utero exposure to Vinclozolin significantly reduced AGD, increased testicular germ cell apoptosis 3-fold, reduced elongated spermatid number by 40%, and induced postpubertal prostatitis in 100% of exposed males. Administration of high-dose testosterone (25 mg/kg) at puberty normalized AGD, reduced germ cell apoptosis, and restored elongated spermatid number. Testosterone restored AR and nuclear factor-kappaB expression in the prostate and abolished Vinclozolin-induced prostatitis. Altered Dnmt expression was evident with in utero Vinclozolin exposure and was not normalized after testosterone treatment. These data demonstrate in utero Vinclozolin-induced male reproductive tract abnormalities are AR mediated and reversible and involve a mechanism independent of Dnmt expression.

Long-Term Dexamethasone Exposure Down-Regulates Hepatic TFR1 and Reduces Liver Iron Concentration in Rats

PubMed Central

Li, Huifang; Jiang, Shuxia; Yang, Chun; Yang, Shu; He, Bin; Ma, Wenqiang; Zhao, Ruqian

2017-01-01

Exposure to stress is known to cause hepatic iron dysregulation, but the relationship between prolonged stress and liver iron metabolism is not yet fully understood. Thirty 13-week-old female Sprague–Dawley rats were randomly divided into two groups, as follows: the control group (saline-injection) and the dexamethasone group (Dexamethasone (Dex)-injection 0.1 mg/kg/day). After the 21-day stress trial, the results showed that chronic Dex administration not only impaired serum corticosterone (p = 0.00) and interleukin-6 (IL-6) (p = 0.01) levels, but also decreased white blood cell counts (p = 0.00), and reduced blood lymphocyte counts (p = 0.00). The daily Dex-injection also significantly reduced body weight (p < 0.01) by inhibiting food intake. Consecutive Dex administration resulted in decreased iron intake (p = 0.00), enhanced serum iron levels (p = 0.01), and increased the serum souble transferrin receptor (sTfR) content (p = 0.00) in rats. Meanwhile, long-term Dex exposure down-regulated duodenal cytochrome b (DCYTB) (p = 0.00) and the divalent metal transporter 1 (DMT1) (p = 0.04) protein expression, but up-regulated ferroportin (FPN) protein expression (p = 0.04). Chronic Dex administration reduced liver iron concentration (p = 0.02) in rats. Hepatic transferrin receptor 1 (TFR1) expression was lowered at the protein level (p = 0.03), yet with uncoupled mRNA abundance in Dex-treated rats. Enhanced iron-regulatory protein (IRP)/iron-responsive element (IRE) binding activity was observed, but did not line up with lowered hepatic TFR1 protein expression. This study indicates that long-term Dex exposure reduces liver iron content, which is closely associated with down-regulated hepatic TFR1 protein expression. PMID:28629118

Reduction of exposure to acrylamide: achievements, potential of optimization, and problems encountered from the perspectives of a Swiss enforcement laboratory.

PubMed

Grob, Koni

2005-01-01

The most important initiatives taken in Switzerland to reduce exposure of consumers to acrylamide are the separate sale of potatoes low in reducing sugars for roasting and frying, the optimization of the raw material and preparation of french fries, and campaigns to implement suitable preparation methods in the gastronomy and homes. Industry works on improving a range of other products. Although these measures can reduce high exposures by some 80%, they have little effect on the background exposure resulting from coffee, bread, and numerous other products for which no substantial improvement is in sight. At this stage, improvements should be achieved by supporting voluntary activity rather than legal limits. Committed and consistent risk communication is key, and the support of improvements presupposes innovative approaches.

A Behavioral Intervention to Reduce Child Exposure to Indoor Air Pollution: Identifying Possible Target Behaviors

ERIC Educational Resources Information Center

Barnes, Brendon R.; Mathee, Angela; Shafritz, Lonna B.; Krieger, Laurie; Zimicki, Susan

2004-01-01

Indoor air pollution has been causally linked to acute lower respiratory infections in children younger than 5. The aim of this study was to identify target behaviors for a behavioral intervention to reduce child exposure to indoor air pollution by attempting to answer two research questions: Which behaviors are protective of child respiratory…

Effect of reduced exposure times on the cytotoxicity of resin luting cements cured by high-power led

PubMed Central

ERGUN, Gulfem; EGILMEZ, Ferhan; YILMAZ, Sukran

2011-01-01

Objective Applications of resin luting agents and high-power light-emitting diodes (LED) light-curing units (LCUs) have increased considerably over the last few years. However, it is not clear whether the effect of reduced exposure time on cytotoxicity of such products have adequate biocompatibility to meet clinical success. This study aimed at assessing the effect of reduced curing time of five resin luting cements (RLCs) polymerized by high-power LED curing unit on the viability of a cell of L-929 fibroblast cells. Material and Methods Disc-shaped samples were prepared in polytetrafluoroethylene moulds with cylindrical cavities. The samples were irradiated from the top through the ceramic discs and acetate strips using LED LCU for 20 s (50% of the manufacturer's recommended exposure time) and 40 s (100% exposure time). After curing, the samples were transferred into a culture medium for 24 h. The eluates were obtained and pipetted onto L-929 fibroblast cultures (3x104 per well) and incubated for evaluating after 24 h. Measurements were performed by dimethylthiazol diphenyltetrazolium assay. Statistical significance was determined by two-way ANOVA and two independent samples were compared by t-test. Results Results showed that eluates of most of the materials polymerized for 20 s (except Rely X Unicem and Illusion) reduced to a higher extent cell viability compared to samples of the same materials polymerized for 40 s. Illusion exhibited the least cytotoxicity for 20 s exposure time compared to the control (culture without samples) followed by Rely X Unicem and Rely X ARC (90.81%, 88.90%, and 83.11%, respectively). For Rely X ARC, Duolink and Lute-It 40 s exposure time was better (t=-1.262 p=0,276; t=-9.399 p=0.001; and t=-20.418 p<0.001, respectively). Conclusion The results of this study suggest that reduction of curing time significantly enhances the cytotoxicity of the studied resin cement materials, therefore compromising their clinical performance. PMID

Potential pathways by which maternal second-hand smoke exposure during pregnancy causes full-term low birth weight.

PubMed

Niu, Zhongzheng; Xie, Chuanbo; Wen, Xiaozhong; Tian, Fuying; Yuan, Shixin; Jia, Deqin; Chen, Wei-Qing

2016-04-29

It is well documented that maternal exposure to second-hand smoke (SHS) during pregnancy causes low birth weight (LBW), but its mechanism remains unknown. This study explored the potential pathways. We enrolled 195 pregnant women who delivered full-term LBW newborns, and 195 who delivered full-term normal birth weight newborns as the controls. After controlling for maternal age, education level, family income, pre-pregnant body mass index, newborn gender and gestational age, logistic regression analysis revealed that LBW was significantly and positively associated with maternal exposure to SHS during pregnancy, lower placental weight, TNF-α and IL-1β, and that SHS exposure was significantly associated with lower placental weight, TNF-α and IL-1β. Structural equation modelling identified two plausible pathways by which maternal exposure to SHS during pregnancy might cause LBW. First, SHS exposure induced the elevation of TNF-α, which might directly increase the risk of LBW by transmission across the placenta. Second, SHS exposure first increased maternal secretion of IL-1β and TNF-α, which then triggered the secretion of VCAM-1; both TNF-α and VCAM-1 were significantly associated with lower placental weight, thus increasing the risk of LBW. In conclusion, maternal exposure to SHS during pregnancy may lead to LBW through the potential pathways of maternal inflammation and lower placental weight.

Reducing youth exposure to alcohol ads: targeting public transit.

PubMed

Simon, Michele

2008-07-01

Underage drinking is a major public health problem. Youth drink more heavily than adults and are more vulnerable to the adverse effects of alcohol. Previous research has demonstrated the connection between alcohol advertising and underage drinking. Restricting outdoor advertising in general and transit ads in particular, represents an important opportunity to reduce youth exposure. To address this problem, the Marin Institute, an alcohol industry watchdog group in Northern California, conducted a survey of alcohol ads on San Francisco bus shelters. The survey received sufficient media attention to lead the billboard company, CBS Outdoor, into taking down the ads. Marin Institute also surveyed the 25 largest transit agencies; results showed that 75 percent of responding agencies currently have policies that ban alcohol advertising. However, as the experience in San Francisco demonstrated, having a policy on paper does not necessarily mean it is being followed. Communities must be diligent in holding accountable government officials, the alcohol industry, and the media companies through which advertising occurs.

Reducing Youth Exposure to Alcohol Ads: Targeting Public Transit

PubMed Central

2008-01-01

Underage drinking is a major public health problem. Youth drink more heavily than adults and are more vulnerable to the adverse effects of alcohol. Previous research has demonstrated the connection between alcohol advertising and underage drinking. Restricting outdoor advertising in general and transit ads in particular, represents an important opportunity to reduce youth exposure. To address this problem, the Marin Institute, an alcohol industry watchdog group in Northern California, conducted a survey of alcohol ads on San Francisco bus shelters. The survey received sufficient media attention to lead the billboard company, CBS Outdoor, into taking down the ads. Marin Institute also surveyed the 25 largest transit agencies; results showed that 75 percent of responding agencies currently have policies that ban alcohol advertising. However, as the experience in San Francisco demonstrated, having a policy on paper does not necessarily mean it is being followed. Communities must be diligent in holding accountable government officials, the alcohol industry, and the media companies through which advertising occurs. PMID:18389374

Increased Lung Cancer Mortality in Taconite Mining: The Potential for Disease from Elongate Mineral Particle Exposure.

PubMed

Mandel, Jeffrey H; Ramachandran, Gurumurthy; Alexander, Bruce H

2016-02-15

Taconite mining involves potential exposure to non-asbestiform amphibole mineral fiber. More recent studies have demonstrated increased mortality from respiratory cancers and heart disease among workers in the taconite industry. This finding is not consistent with recent exposure assessment findings, nor is the toxicology of this mineral suggestive of neoplastic disease. The understanding of respiratory disease in taconite mining is hampered by the lack of exposure data to asbestiform mineral fibers that occurred in the 1950s and 1960s. Other industries with similar mineral exposure have not demonstrated definitive associations with respiratory cancer, although non-malignant respiratory disease is a consistent finding in epidemiological studies.

Effects of a Parent-Child Interactive Program for Families on Reducing the Exposure of School-Aged Children to Household Smoking.

PubMed

Chen, Yu-Ting; Hsiao, Fei-Hsiu; Lee, Ching-Mei; Wang, Ruey-Hsia; Chen, Ping-Ling

2016-03-01

Parental smoking has been identified as the major source of children's exposure to environmental tobacco smoke (ETS). Therefore, parental involvement is critical in ETS exposure prevention programs. This study examined the effects of a parent-child interactive program on reducing children's exposure to ETS at home and enhancing parents' and children's prevention strategies. A clustered randomized controlled trial was administered to 75 families of school-aged children from six primary schools in New Taipei City, Taiwan. Families in the intervention group received a parent-child interactive intervention, and parents in the control group received written materials on tobacco hazards. Data on children's exposure and the prevention of children's exposure to ETS at home were obtained at baseline, 8-week, and 20-week or 6-month assessments. The percentage of children with urine cotinine levels greater than or equal to 6 ng/ml was significantly lower in the intervention group than it was in the control group at both the 8-week and 6-month assessments. The intervention significantly reduced parental smoking in the presence of children and increased parents' prevention of children's ETS exposure and children's ETS avoidance behavior from the baseline to the 20-week assessment. This is a preliminary study design aimed at creating a program for reducing children's ETS exposure at home. Further research to produce evidence supporting the application of the parent-child interactive program in primary schools is suggested. The theoretical basis of the intervention design can serve as a reference for nursing education and the design of health education programs. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Neonatal exposure to phenobarbital potentiates schizophrenia-like behavioral outcomes in the rat.

PubMed

Bhardwaj, S K; Forcelli, P A; Palchik, G; Gale, K; Srivastava, L K; Kondratyev, A

2012-06-01

Previous work has indicated an association between seizures early in life and increased risk of psychiatric disorders, including schizophrenia. However, because early-life seizures are commonly treated with antiepileptic drugs (AEDs) such as phenobarbital, the possibility that drug treatment may affect later-life psychiatric outcomes needs to be evaluated. We therefore tested the hypothesis that phenobarbital exposure in the neonatal rat increases the risk of schizophrenia-like behavioral abnormalities in adulthood. Thus, in this study, we examined the effects of a single acute neonatal exposure to phenobarbital on adult behavioral outcomes in the rat neonatal ventral hippocampal (nVH) lesion model of schizophrenia. We compared these outcomes to those in rats a) without nVH lesions and b) with nVH lesions, without phenobarbital. The tasks used for behavioral evaluation were: amphetamine-induced locomotion, prepulse inhibition, elevated plus-maze, and novel object recognition task. We found that neonatal phenobarbital treatment (in the absence of nVH lesions) was sufficient to disrupt sensorimotor gating (as tested by prepulse inhibition) in adulthood to an extent equivalent to nVH lesions. Additionally, neonatal phenobarbital exposure enhanced the locomotor response to amphetamine in adult animals with and without nVH lesions. Our findings suggest that neonatal exposure to phenobarbital can predispose to schizophrenia-like behavioral abnormalities. Our findings underscore the importance of examining AED exposure early in life as a potential risk factor for later-life neuropsychiatric abnormalities in clinical populations. Copyright © 2012 Elsevier Ltd. All rights reserved.

Neonatal exposure to phenobarbital potentiates schizophrenia-like behavioral outcomes in the rat

PubMed Central

Bhardwaj, S.K.; Forcelli, P.A; Palchik, G.; Gale, K.; Srivastava, L.K.; Kondratyev, A.

2012-01-01

Previous work has indicated an association between seizures early in life and increased risk of psychiatric disorders, including schizophrenia. However, because early life seizures are commonly treated with antiepileptic drugs (AEDs) such as phenobarbital, the possibility that drug treatment may affect later-life psychiatric outcomes needs to be evaluated. We therefore tested the hypothesis that phenobarbital exposure in the neonatal rat increases the risk of schizophrenia-like behavioral abnormalities in adulthood. Thus, in this study, we examined the effects of a single acute neonatal exposure to phenobarbital on adult behavioral outcomes in the rat neonatal ventral hippocampal (nVH) lesion model of schizophrenia. We compared these outcomes to those in rats a) without nVH lesions and b) with nVH lesions, without phenobarbital. The tasks used for behavioral evaluation were: amphetamine-induced locomotion, prepulse inhibition, elevated plus-maze, and novel object recognition task. We found that neonatal phenobarbital treatment (in the absence of nVH lesions) was sufficient to disrupt sensorimotor gating (as tested by prepulse inhibition) in adulthood to an extent equivalent to nVH lesions. Additionally, neonatal phenobarbital exposure enhanced the locomotor response to amphetamine in adult animals with and without nVH lesions. Our findings suggest that neonatal exposure to phenobarbital can predispose to schizophrenia-like behavioral abnormalities. Our findings underscore the importance of examining AED exposure early in life as a potential risk factor for later-life neuropsychiatric abnormalities in clinical populations. PMID:22366076

[Exposure to addictogenic substances, conditioned response and treatment of the exposure with response prevention].

PubMed

Khazaal, Y; Frésard, E; Zullino, D

2007-01-01

Exposure to drugs or related cues is associated with psycho-physiological reactivity. These responses are conditioned during periods of active consumption. Exposure with response prevention (EPR) is a treatment established for anxiety disorder and aims to reduce anxiety by an extinction of previously conditioned responses. The conditioning recognized in additive processes has led to research into EPR's therapeutic potential for treating addiction. This paper is a review of the main studies on reactivity to cues, and EPR, particularly with respect to addiction to alcohol, opiates, cocaine and tobacco. This review is based on information from the Medline database, dealing with cue reactivity, attentional bias during exposure to cues and exposure treatment for addiction in general and, in particular, for each of the aforementioned substances. Exposure to drug-related cues is clearly associated with psycho-physiological reactivity and with attentional bias. Those phenomena are associated with craving and more difficulty in maintaining abstinence. The subject's attention is thus held by a large number of drug-related environmental stimuli. These observations are linked with conditioning phenomena and suggest the possibility of treatment by EPR conditioning extinction procedures. EPR has been most widely studied for abuse and alcohol addiction. Case reports give favourable outcomes. Results from controlled studies are less clear. Studies on patients addicted to cocaine or heroine are still limited and not conclusive. Different controlled studies on EPR for nicotine addiction have not produced conclusions in favour of this treatment. Generally, the EPR procedures used vary among studies. Studies focussing particularly on the evolution of physiological responses in a laboratory setting after EPR have demonstrated reduced autonomic nervous system activity. These results do not consistently lead to a reduction in consumption behaviour and in craving when the patient is in

Developmental Ethanol Exposure Causes Reduced Feeding and Reveals a Critical Role for Neuropeptide F in Survival

PubMed Central

Guevara, Amanda; Gates, Hillary; Urbina, Brianna; French, Rachael

2018-01-01

Food intake is necessary for survival, and natural reward circuitry has evolved to help ensure that animals ingest sufficient food to maintain development, growth, and survival. Drugs of abuse, including alcohol, co-opt the natural reward circuitry in the brain, and this is a major factor in the reinforcement of drug behaviors leading to addiction. At the junction of these two aspects of reward are alterations in feeding behavior due to alcohol consumption. In particular, developmental alcohol exposure (DAE) results in a collection of physical and neurobehavioral disorders collectively referred to as Fetal Alcohol Spectrum Disorder (FASD). The deleterious effects of DAE include intellectual disabilities and other neurobehavioral changes, including altered feeding behaviors. Here we use Drosophila melanogaster as a genetic model organism to study the effects of DAE on feeding behavior and the expression and function of Neuropeptide F. We show that addition of a defined concentration of ethanol to food leads to reduced feeding at all stages of development. Further, genetic conditions that reduce or eliminate NPF signaling combine with ethanol exposure to further reduce feeding, and the distribution of NPF is altered in the brains of ethanol-supplemented larvae. Most strikingly, we find that the vast majority of flies with a null mutation in the NPF receptor die early in larval development when reared in ethanol, and provide evidence that this lethality is due to voluntary starvation. Collectively, we find a critical role for NPF signaling in protecting against altered feeding behavior induced by developmental ethanol exposure. PMID:29623043

Methods for finding transition states on reduced potential energy surfaces

NASA Astrophysics Data System (ADS)

Burger, Steven K.; Ayers, Paul W.

2010-06-01

Three new algorithms are presented for determining transition state (TS) structures on the reduced potential energy surface, that is, for problems in which a few important degrees of freedom can be isolated. All three methods use constrained optimization to rapidly find the TS without an initial Hessian evaluation. The algorithms highlight how efficiently the TS can be located on a reduced surface, where the rest of the degrees of freedom are minimized. The first method uses a nonpositive definite quasi-Newton update for the reduced degrees of freedom. The second uses Shepard interpolation to fit the Hessian and starts from a set of points that bound the TS. The third directly uses a finite difference scheme to calculate the reduced degrees of freedom of the Hessian of the entire system, and searches for the TS on the full potential energy surface. All three methods are tested on an epoxide hydrolase cluster, and the ring formations of cyclohexane and cyclobutenone. The results indicate that all the methods are able to converge quite rapidly to the correct TS, but that the finite difference approach is the most efficient.

Methods for finding transition states on reduced potential energy surfaces.

PubMed

Burger, Steven K; Ayers, Paul W

2010-06-21

Three new algorithms are presented for determining transition state (TS) structures on the reduced potential energy surface, that is, for problems in which a few important degrees of freedom can be isolated. All three methods use constrained optimization to rapidly find the TS without an initial Hessian evaluation. The algorithms highlight how efficiently the TS can be located on a reduced surface, where the rest of the degrees of freedom are minimized. The first method uses a nonpositive definite quasi-Newton update for the reduced degrees of freedom. The second uses Shepard interpolation to fit the Hessian and starts from a set of points that bound the TS. The third directly uses a finite difference scheme to calculate the reduced degrees of freedom of the Hessian of the entire system, and searches for the TS on the full potential energy surface. All three methods are tested on an epoxide hydrolase cluster, and the ring formations of cyclohexane and cyclobutenone. The results indicate that all the methods are able to converge quite rapidly to the correct TS, but that the finite difference approach is the most efficient.

Will the Occupational Safety and Health Administration's Proposed Standards for Occupational Exposure to Respirable Crystalline Silica Reduce Workplace Risk?

PubMed

Dudley, Susan E; Morriss, Andrew P

2015-07-01

The Occupational Safety and Health Administration (OSHA) is developing regulations to amend existing standards for occupational exposure to respirable crystalline silica by establishing a new permissible exposure limit as well as a series of ancillary provisions for controlling exposure. This article briefly reviews OSHA's proposed regulatory approach and the statutory authority on which it is based. It then evaluates OSHA's preliminary determination of significant risk and its analysis of the risk reduction achievable by its proposed controls. It recognizes that OSHA faces multiple challenges in devising a regulatory approach that reduces exposures and health risks and meets its statutory goal. However, the greatest challenge to reducing risks associated with silica exposure is not the lack of incentives (for either employers or employees) but rather lack of information, particularly information on the relative toxicity of different forms of silica. The article finds that OSHA's proposed rule would contribute little in the way of new information, particularly since it is largely based on information that is at least a decade old--a significant deficiency, given the rapidly changing conditions observed over the last 45 years. The article concludes with recommendations for alternative approaches that would be more likely to generate information needed to improve worker health outcomes. © 2015 Society for Risk Analysis.

Neural evidence for reduced apprehensiveness of familiarized stimuli in a mere exposure paradigm.

PubMed

Zebrowitz, Leslie A; Zhang, Yi

2012-07-01

Mere familiarization with a stimulus increases liking for it or similar stimuli ("mere exposure" effects) as well as perceptual fluency, indexed by the speed and accuracy of categorizing it or similar stimuli ("priming" effects). Candidate mechanisms proposed to explain mere exposure effects include both increased positive affect associated with greater perceptual fluency, and reduced negative affect associated with diminished apprehensiveness of novel stimuli. Although these two mechanisms are not mutually exclusive, it is difficult for behavioral measures to disentangle them, since increased liking or other indices of greater positive affect toward exposed stimuli could result from increases in positive feelings or decreases in negative feelings or both. The present study sought to clarify this issue by building on research showing a dissociation at the neural level in which the lateral orbitofrontal cortex (LOFC) is activated more by negatively valenced than by neutral or positively valenced stimuli, with the reverse effect for medial orbitofrontal cortex (MOFC). Supporting the reduced apprehensiveness hypothesis, we found lower LOFC activation to familiarized faces and objects (repetition suppression). We did not find evidence to support the positive affect hypothesis in increased activation to familiarized stimuli in MOFC or in other parts of the reward circuit that respond more to positively valenced stimuli (repetition enhancement), although enhancement effects were shown in some regions.

A systematic approach to community resilience that reduces the federal fiscal exposure to climate change

NASA Astrophysics Data System (ADS)

Stwertka, C.; Albert, M. R.; White, K. D.

2016-12-01

Despite widely available information about the adverse impacts of climate change to the public, including both private sector and federal fiscal exposure, there remain opportunities to effectively translate this knowledge into action. Further delay of climate preparedness and resilience actions imposes a growing toll on American communities and the United States fiscal budget. We hypothesize that a set of four criteria must be met before a community can translate climate disturbances into preparedness action. We examine four case studies to review these proposed criteria, we discuss the critical success factors that can build community resilience, and we define an operational strategy that could support community resilience while reducing the federal fiscal exposure to climate change. This operational strategy defines a community response system that integrates social science research, builds on the strengths of different sectors, values existing resources, and reduces the planning-to-action time. Our next steps are to apply this solution in the field, and to study the dynamics of community engagement and the circular economy.

Evaluation of an initiative to reduce radiation exposure from CT to children in a non-pediatric-focused facility.

PubMed

Blumfield, Einat; Zember, Jonathan; Guelfguat, Mark; Blumfield, Amit; Goldman, Harold

2015-12-01

We would like to share our experience of reducing pediatric radiation exposure. Much of the recent literature regarding successes of reducing radiation exposure has come from dedicated children's hospitals. Nonetheless, over the past two decades, there has been a considerable increase in CT imaging of children in the USA, predominantly in non-pediatric-focused facilities where the majority of children are treated. In our institution, two general hospitals with limited pediatric services, a dedicated initiative intended to reduce children's exposure to CT radiation was started by pediatric radiologists in 2005. The initiative addressed multiple issues including eliminating multiphase studies, decreasing inappropriate scans, educating referring providers, training residents and technologists, replacing CT with ultrasound or MRI, and ensuring availability of pediatric radiologists for consultation. During the study period, the total number of CT scans decreased by 24 %. When accounting for the number of scans per visit to the emergency department (ED), the numbers of abdominal and head CT scans decreased by 37.2 and 35.2 %, respectively. For abdominal scans, the average number of phases per scan decreased from 1.70 to 1.04. Upon surveying the pediatric ED staff, it was revealed that the most influential factors on ordering of scans were daily communication with pediatric radiologists, followed by journal articles and lectures by pediatric radiologists. We concluded that a non-pediatric-focused facility can achieve dramatic reduction in CT radiation exposure to children; however, this is most effectively achieved through a dedicated, multidisciplinary process led by pediatric radiologists.

Estrogenic Exposure Alters the Spermatogonial Stem Cells in the Developing Testis, Permanently Reducing Crossover Levels in the Adult

PubMed Central

Vrooman, Lisa A.; Oatley, Jon M.; Griswold, Jodi E.; Hassold, Terry J.; Hunt, Patricia A.

2015-01-01

Bisphenol A (BPA) and other endocrine disrupting chemicals have been reported to induce negative effects on a wide range of physiological processes, including reproduction. In the female, BPA exposure increases meiotic errors, resulting in the production of chromosomally abnormal eggs. Although numerous studies have reported that estrogenic exposures negatively impact spermatogenesis, a direct link between exposures and meiotic errors in males has not been evaluated. To test the effect of estrogenic chemicals on meiotic chromosome dynamics, we exposed male mice to either BPA or to the strong synthetic estrogen, ethinyl estradiol during neonatal development when the first cells initiate meiosis. Although chromosome pairing and synapsis were unperturbed, exposed outbred CD-1 and inbred C3H/HeJ males had significantly reduced levels of crossovers, or meiotic recombination (as defined by the number of MLH1 foci in pachytene cells) by comparison with placebo. Unexpectedly, the effect was not limited to cells exposed at the time of meiotic entry but was evident in all subsequent waves of meiosis. To determine if the meiotic effects induced by estrogen result from changes to the soma or germline of the testis, we transplanted spermatogonial stem cells from exposed males into the testes of unexposed males. Reduced recombination was evident in meiocytes derived from colonies of transplanted cells. Taken together, our results suggest that brief exogenous estrogenic exposure causes subtle changes to the stem cell pool that result in permanent alterations in spermatogenesis (i.e., reduced recombination in descendent meiocytes) in the adult male. PMID:25615633

Impact of temporal upscaling and chemical transport model horizontal resolution on reducing ozone exposure misclassification

NASA Astrophysics Data System (ADS)

Xu, Yadong; Serre, Marc L.; Reyes, Jeanette M.; Vizuete, William

2017-10-01

We have developed a Bayesian Maximum Entropy (BME) framework that integrates observations from a surface monitoring network and predictions from a Chemical Transport Model (CTM) to create improved exposure estimates that can be resolved into any spatial and temporal resolution. The flexibility of the framework allows for input of data in any choice of time scales and CTM predictions of any spatial resolution with varying associated degrees of estimation error and cost in terms of implementation and computation. This study quantifies the impact on exposure estimation error due to these choices by first comparing estimations errors when BME relied on ozone concentration data either as an hourly average, the daily maximum 8-h average (DM8A), or the daily 24-h average (D24A). Our analysis found that the use of DM8A and D24A data, although less computationally intensive, reduced estimation error more when compared to the use of hourly data. This was primarily due to the poorer CTM model performance in the hourly average predicted ozone. Our second analysis compared spatial variability and estimation errors when BME relied on CTM predictions with a grid cell resolution of 12 × 12 km2 versus a coarser resolution of 36 × 36 km2. Our analysis found that integrating the finer grid resolution CTM predictions not only reduced estimation error, but also increased the spatial variability in daily ozone estimates by 5 times. This improvement was due to the improved spatial gradients and model performance found in the finer resolved CTM simulation. The integration of observational and model predictions that is permitted in a BME framework continues to be a powerful approach for improving exposure estimates of ambient air pollution. The results of this analysis demonstrate the importance of also understanding model performance variability and its implications on exposure error.

Coccidioides Exposure and Coccidioidomycosis among Prison Employees, California, United States

PubMed Central

Niemeier, R. Todd; Burr, Gregory A.

2015-01-01

Responding to a request by corrections agency management, we investigated coccidioidomycosis in prison employees in central California, a coccidioidomycosis-endemic area. We identified 103 cases of coccidioidomycosis that occurred over 4.5 years. As a result, we recommended training and other steps to reduce dust exposure among employees and thus potential exposure to Coccidioides. PMID:25989420

The inoculating role of previous exposure to potentially traumatic life events on coping with prolonged exposure to rocket attacks: A lifespan perspective.

PubMed

Palgi, Yuval; Gelkopf, Marc; Berger, Rony

2015-06-30

Relatively little research have addressed the effect of prolonged exposure to rocket attacks with a lifespan perspective and only a handful of these studies focused on the effect of this exposure as a function of aging. The present study examined the effects of seven years of rocket attacks fired toward the south of Israel on adult participants of different ages. We examined whether potentially traumatic life events (PTLEs) unrelated to rocket attacks moderated the association between post-traumatic stress (PTS) symptoms and age. Data were obtained from a 2007 telephone survey using the Random Digit Dialing method and including 343 individuals (76.7% participation rate). Exposure to rockets, PTLEs, global distress, and post-traumatic symptomatology were assessed. Older age was associated with a higher level of PTS symptoms. Higher PTLE levels attenuated the association between age and PTS symptoms. Our results suggest that age is a risk factor for developing PTS symptoms under prolonged exposure to rocket attacks. However, previous levels of exposure to other negative events, as well as gender, appear to inoculate a person to stress, thus modulating the age-PTS association. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A RANDOMIZED CONTROLLED TRIAL OF PROGRESSIVELY REDUCED NICOTINE CONTENT CIGARETTES ON SMOKING BEHAVIORS, BIOMARKERS OF EXPOSURE, AND SUBJECTIVE RATINGS

PubMed Central

Mercincavage, Melissa; Souprountchouk, Valentina; Tang, Kathy Z.; Dumont, Rachel L.; Wileyto, E. Paul; Carmella, Steven G.; Hecht, Stephen S.; Strasser, Andrew A.

2016-01-01

Background The U.S. FDA has the authority to reduce cigarette nicotine content if found to benefit public health. Reduced nicotine content (RNC) cigarette use does not appear to increase harm exposure, but studies have not rigorously assessed smoking behavior or utilized a comprehensive panel of biomarkers. This study examined the effects of progressively decreasing RNC cigarettes on smoking behaviors, biomarkers of exposure, and subjective ratings. Methods 158 daily, non-treatment-seeking smokers participated in a 35-day randomized, unblinded, parallel study. After a 5-day baseline period, participants were randomly assigned to an experimental group (n = 80) that smoked progressively decreasing RNC cigarettes during three 10-day periods, or control group (n =78) that smoked their own brand throughout the study. Results Daily cigarette consumption significantly increased for the intermediate RNCs (P’s < 0.001) but approached baseline rate for the lowest RNC (P = 0.686); in contrast, puffing behavior significantly decreased at intermediate levels and increased for the lowest RNC (P’s < 0.001). Cotinine and NNAL significantly decreased by RNC period (P’s ≤ 0.001–0.02), while CO boost initially increased (P’s = 0.001–0.005). 1-HOP did not change by period (P = 0.109). Conclusions Smoking behaviors changed by RNC period via CPD and puffing behavior. Biomarkers of exposure generally decreased with nicotine content. Impact Findings suggest that RNC use does not ubiquitously reduce smoking behaviors or biomarkers, yet the lowest RNC level tested may reduce harm exposure. This emphasizes the importance of utilizing multiple behavioral and biological measures to address the impact of RNC cigarette smoking. PMID:27197288

Stress exposure in early post-natal life reduces telomere length: an experimental demonstration in a long-lived seabird

PubMed Central

Herborn, Katherine A.; Heidinger, Britt J.; Boner, Winnie; Noguera, Jose C.; Adam, Aileen; Daunt, Francis; Monaghan, Pat

2014-01-01

Exposure to stressors early in life is associated with faster ageing and reduced longevity. One important mechanism that could underlie these late life effects is increased telomere loss. Telomere length in early post-natal life is an important predictor of subsequent lifespan, but the factors underpinning its variability are poorly understood. Recent human studies have linked stress exposure to increased telomere loss. These studies have of necessity been non-experimental and are consequently subjected to several confounding factors; also, being based on leucocyte populations, where cell composition is variable and some telomere restoration can occur, the extent to which these effects extend beyond the immune system has been questioned. In this study, we experimentally manipulated stress exposure early in post-natal life in nestling European shags (Phalacrocorax aristotelis) in the wild and examined the effect on telomere length in erythrocytes. Our results show that greater stress exposure during early post-natal life increases telomere loss at this life-history stage, and that such an effect is not confined to immune cells. The delayed effects of increased telomere attrition in early life could therefore give rise to a ‘time bomb’ that reduces longevity in the absence of any obvious phenotypic consequences early in life. PMID:24648221

Characterization of silver nanoparticles in selected consumer products and its relevance for predicting children's potential exposures.

PubMed

Tulve, Nicolle S; Stefaniak, Aleksandr B; Vance, Marina E; Rogers, Kim; Mwilu, Samuel; LeBouf, Ryan F; Schwegler-Berry, Diane; Willis, Robert; Thomas, Treye A; Marr, Linsey C

2015-05-01

Due to their antifungal, antibacterial, antiviral, and antimicrobial properties, silver nanoparticles (AgNPs) are used in consumer products intended for use by children or in the home. Children may be especially affected by the normal use of consumer products because of their physiological functions, developmental stage, and activities and behaviors. Despite much research to date, children's potential exposures to AgNPs are not well characterized. Our objectives were to characterize selected consumer products containing AgNPs and to use the data to estimate a child's potential non-dietary ingestion exposure. We identified and cataloged 165 consumer products claiming to contain AgNPs that may be used by or near children or found in the home. Nineteen products (textile, liquid, plastic) were selected for further analysis. We developed a tiered analytical approach to determine silver content, form (particulate or ionic), size, morphology, agglomeration state, and composition. Silver was detected in all products except one sippy cup body. Among products in a given category, silver mass contributions were highly variable and not always uniformly distributed within products, highlighting the need to sample multiple areas of a product. Electron microscopy confirmed the presence of AgNPs. Using this data, a child's potential non-dietary ingestion exposure to AgNPs when drinking milk formula from a sippy cup is 1.53 μg Ag/kg. Additional research is needed to understand the number and types of consumer products containing silver and the concentrations of silver in these products in order to more accurately predict children's potential aggregate and cumulative exposures to AgNPs. Published by Elsevier GmbH.

Embryonic Methamphetamine Exposure Inhibits Methamphetamine Cue Conditioning and Reduces Dopamine Concentrations in Adult N2 C. elegans

PubMed Central

Katner, S.N.; Neal-Beliveau, B.S.; Engleman, E.A.

2016-01-01

Methamphetamine (MAP) addiction is substantially prevalent in today's society, resulting in thousands of deaths and costing billions of dollars annually. Despite the potential deleterious consequences, few studies have examined the long-term effects of embryonic MAP exposure. Using the invertebrate nematode Caenorhabditis elegans (C. elegans) allows for a controlled analysis of behavioral and neurochemical changes due to early developmental drug exposure. The objective of the current studies was to determine the long-term behavioral and neurochemical effects of embryonic exposure to MAP in C. elegans. In addition, we sought to improve our conditioning and testing procedures by utilizing liquid filtration, as opposed to agar, and smaller, 6-well testing plates to increase throughput. Wild-type N2 C. elegans were embryonically exposed to 50 μM MAP. Using classical conditioning, adult-stage C. elegans were conditioned to MAP (17 and 500 μM) in the presence of either sodium ions (Na+) or chloride (Cl-) ions as conditioned stimuli (CS+/CS-). Following conditioning, a preference test was performed by placing worms in 6-well test plates spotted with the CS+ and CS- at opposite ends of each well. A preference index (PI) was determined by counting the number of worms in the CS+ target zone divided by the total number of worms in the CS+ and CS- target zones. A food conditioning experiment was also performed in order to determine if embryonic MAP exposure affected food conditioning behavior. For the neurochemical experiments, adult worms that were embryonically exposed to MAP were analyzed for (dopamine) DA content using high performance liquid chromatography (HPLC). The liquid filtration conditioning procedure employed here in combination with the use 6-well test plates significantly decreased the time required to perform these experiments and ultimately increased throughput. The MAP conditioning data found that pairing an ion with MAP at 17 or 500 μM significantly

Embryonic Methamphetamine Exposure Inhibits Methamphetamine Cue Conditioning and Reduces Dopamine Concentrations in Adult N2 Caenorhabditis elegans.

PubMed

Katner, Simon N; Neal-Beliveau, Bethany S; Engleman, Eric A

2016-01-01

Methamphetamine (MAP) addiction is substantially prevalent in today's society, resulting in thousands of deaths and costing billions of dollars annually. Despite the potential deleterious consequences, few studies have examined the long-term effects of embryonic MAP exposure. Using the invertebrate nematode Caenorhabditis elegans allows for a controlled analysis of behavioral and neurochemical changes due to early developmental drug exposure. The objective of the current study was to determine the long-term behavioral and neurochemical effects of embryonic exposure to MAP in C. elegans. In addition, we sought to improve our conditioning and testing procedures by utilizing liquid filtration, as opposed to agar, and smaller, 6-well testing plates to increase throughput. Wild-type N2 C. elegans were embryonically exposed to 50 μM MAP. Using classical conditioning, adult-stage C. elegans were conditioned to MAP (17 and 500 μM) in the presence of either sodium ions (Na+) or chloride ions (Cl-) as conditioned stimuli (CS+/CS-). Following conditioning, a preference test was performed by placing worms in 6-well test plates spotted with the CS+ and CS- at opposite ends of each well. A preference index was determined by counting the number of worms in the CS+ target zone divided by the total number of worms in the CS+ and CS- target zones. A food conditioning experiment was also performed in order to determine whether embryonic MAP exposure affected food conditioning behavior. For the neurochemical experiments, adult worms that were embryonically exposed to MAP were analyzed for dopamine (DA) content using high-performance liquid chromatography. The liquid filtration conditioning procedure employed here in combination with the use of 6-well test plates significantly decreased the time required to perform these experiments and ultimately increased throughput. The MAP conditioning data found that pairing an ion with MAP at 17 or 500 μM significantly increased the preference

Reduced exposure using asymmetric cone beam processing for wide area detector cardiac CT

PubMed Central

Bedayat, Arash; Kumamaru, Kanako; Powers, Sara L.; Signorelli, Jason; Steigner, Michael L.; Steveson, Chloe; Soga, Shigeyoshi; Adams, Kimberly; Mitsouras, Dimitrios; Clouse, Melvin; Mather, Richard T.

2011-01-01

The purpose of this study was to estimate dose reduction after implementation of asymmetrical cone beam processing using exposure differences measured in a water phantom and a small cohort of clinical coronary CTA patients. Two separate 320 × 0.5 mm detector row scans of a water phantom used identical cardiac acquisition parameters before and after software modifications from symmetric to asymmetric cone beam acquisition and processing. Exposure was measured at the phantom surface with Optically Stimulated Luminescence (OSL) dosimeters at 12 equally spaced angular locations. Mean HU and standard deviation (SD) for both approaches were compared using ROI measurements obtained at the center plus four peripheral locations in the water phantom. To assess image quality, mean HU and standard deviation (SD) for both approaches were compared using ROI measurements obtained at five points within the water phantom. Retrospective evaluation of 64 patients (37 symmetric; 27 asymmetric acquisition) included clinical data, scanning parameters, quantitative plus qualitative image assessment, and estimated radiation dose. In the water phantom, the asymmetric cone beam processing reduces exposure by approximately 20% with no change in image quality. The clinical coronary CTA patient groups had comparable demographics. The estimated dose reduction after implementation of the asymmetric approach was roughly 24% with no significant difference between the symmetric and asymmetric approach with respect to objective measures of image quality or subjective assessment using a four point scale. When compared to a symmetric approach, the decreased exposure, subsequent lower patient radiation dose, and similar image quality from asymmetric cone beam processing supports its routine clinical use. PMID:21336552

Reduced exposure using asymmetric cone beam processing for wide area detector cardiac CT.

PubMed

Bedayat, Arash; Rybicki, Frank J; Kumamaru, Kanako; Powers, Sara L; Signorelli, Jason; Steigner, Michael L; Steveson, Chloe; Soga, Shigeyoshi; Adams, Kimberly; Mitsouras, Dimitrios; Clouse, Melvin; Mather, Richard T

2012-02-01

The purpose of this study was to estimate dose reduction after implementation of asymmetrical cone beam processing using exposure differences measured in a water phantom and a small cohort of clinical coronary CTA patients. Two separate 320 × 0.5 mm detector row scans of a water phantom used identical cardiac acquisition parameters before and after software modifications from symmetric to asymmetric cone beam acquisition and processing. Exposure was measured at the phantom surface with Optically Stimulated Luminescence (OSL) dosimeters at 12 equally spaced angular locations. Mean HU and standard deviation (SD) for both approaches were compared using ROI measurements obtained at the center plus four peripheral locations in the water phantom. To assess image quality, mean HU and standard deviation (SD) for both approaches were compared using ROI measurements obtained at five points within the water phantom. Retrospective evaluation of 64 patients (37 symmetric; 27 asymmetric acquisition) included clinical data, scanning parameters, quantitative plus qualitative image assessment, and estimated radiation dose. In the water phantom, the asymmetric cone beam processing reduces exposure by approximately 20% with no change in image quality. The clinical coronary CTA patient groups had comparable demographics. The estimated dose reduction after implementation of the asymmetric approach was roughly 24% with no significant difference between the symmetric and asymmetric approach with respect to objective measures of image quality or subjective assessment using a four point scale. When compared to a symmetric approach, the decreased exposure, subsequent lower patient radiation dose, and similar image quality from asymmetric cone beam processing supports its routine clinical use.

Does raising awareness in families reduce environmental tobacco smoke exposure in wheezy children?

PubMed Central

Can, Demet; Gunay, Ilker; Karkıner, Canan Sule Unsal; Gunay, Turkan; Cimrin, Dilek; Nalcabasmaz, Tugba

2017-01-01

Introduction Environmental tobacco smoke (ETS) is thought to increase the severity and number of attacks in wheezy children. Objective assessments are needed to change the behavior of families to reduce the exposure of wheezy children to ETS. Aim To determine whether informing families about their children’s urinary cotinine levels curtailed the exposure of children to ETS. Material and methods A survey was used to determine the ETS exposure level, and the urinary cotinine level of each patient was tested. Children with positive urinary cotinine levels were included in the second part of the study. The families were randomly divided into two groups: an intervention group that was advised about urinary cotinine levels by telephone and a non-intervention group that was not so advised. The groups were followed-up 2 months later, and urinary cotinine levels were measured once again. Results The intervention group contained 65 children of average age of 24.4 ±8.9 months, of whom 46 (70.8%) were male. The non-intervention group contained 69 children of average age of 25.3 ±9.8 months (p > 0.05), of whom 52 (75.4%) were male. The urinary cotinine levels at the time of the second interview were lower in both groups. The number of cigarettes that fathers smoked at home decreased in the intervention group (p = 0.037). Conclusions Presenting objective evidence on ETS exposure to families draws attention to their smoking habits. Measurement of cotinine levels is cheap, practical, and noninvasive. Combined with education, creating awareness by measuring cotinine levels may be beneficial. PMID:28951711

Gas-phase organics in environmental tobacco smoke: 2. Exposure-relevant emission factors and indirect exposures from habitual smoking

NASA Astrophysics Data System (ADS)

Singer, Brett C.; Hodgson, Alfred T.; Nazaroff, William W.

, and at lower versus higher ventilation rates. Increasing ventilation can reduce indirect exposures to very low levels for non-sorbing ETS components, but indirect routes accounted for ˜50% of potential nicotine exposures during non-smoking periods at all ventilation rates.

Albumin binding as a potential biomarker of exposure to moderately low levels of organophosphorus pesticides

PubMed Central

Tarhoni, Mabruka H.; Lister, Timothy; Ray, David E.; Carter, Wayne G.

2008-01-01

We have evaluated the potential of plasma albumin to provide a sensitive biomarker of exposure to commonly used organophosphorus pesticides in order to complement the widely used measure of acetylcholinesterase (AChE) inhibition. Rat or human plasma albumin binding by tritiated-diisopropylfluorophosphate (3H-DFP) was quantified by retention of albumin on glass microfibre filters. Preincubation with unlabelled pesticide in vitro or dosing of F344 rats with pesticide in vivo resulted in a reduction in subsequent albumin radiolabelling with 3H-DFP, the decrease in which was used to quantify pesticide binding. At pesticide exposures producing approximately 30% inhibition of AChE, rat plasma albumin binding in vitro by azamethiphos (oxon), chlorfenvinphos (oxon), chlorpyrifos-oxon, diazinon-oxon and malaoxon was reduced from controls by 9±1%, 67±2%, 56±2%, 54±2% and 8±1%, respectively. After 1 h of incubation with 19 µM 3H-DFP alone, the level of binding to rat or human plasma albumins reached 0.011 or 0.039 moles of DFP per mole of albumin, respectively. This level of binding could be further increased by raising the concentration of 3H-DFP, increasing the 3H-DFP incubation time, or by substitution of commercial albumins for native albumin. Pesticide binding to albumin was presumed covalent since it survived 24 h dialysis. After dosing rats with pirimiphos-methyl (dimethoxy) or chlorfenvinphos (oxon) (diethoxy) pesticides, the resultant albumin binding were still significant 7 days after dosing. As in vitro, dosing of rats with malathion did not result in significant albumin binding in vivo. Our results suggest albumin may be a useful additional biomonitor for moderately low-level exposures to several widely used pesticides, and that this binding differs markedly between pesticides. PMID:18484351

Reducing Phthalate, Paraben, and Phenol Exposure from Personal Care Products in Adolescent Girls: Findings from the HERMOSA Intervention Study

PubMed Central

Harley, Kim G.; Kogut, Katherine; Madrigal, Daniel S.; Cardenas, Maritza; Vera, Irene A.; Meza-Alfaro, Gonzalo; She, Jianwen; Gavin, Qi; Zahedi, Rana; Bradman, Asa; Eskenazi, Brenda; Parra, Kimberly L.

2016-01-01

Background: Personal care products are a source of exposure to potentially endocrine-disrupting chemicals such as phthalates, parabens, triclosan, and benzophenone-3 (BP-3) for adolescent girls. Methods: We enrolled 100 Latina girls in a youth-led, community-based participatory research intervention study to determine whether using personal care products whose labels stated they did not contain these chemicals for 3 days could lower urinary concentrations. Pre- and postintervention urine samples were analyzed for phthalate metabolites, parabens, triclosan, and BP-3 using high-performance liquid chromatography/tandem mass spectrometry. Results: Urinary concentrations of mono-ethyl phthalate (MEP) decreased by 27.4% (95% CI: –39.3, –13.2) on average over the 3-day intervention; no significant changes were seen in urinary concentrations of mono-n-butyl phthalate (MnBP) and mono-isobutyl phthalate (MiBP). Methyl and propyl paraben concentrations decreased by 43.9% (95% CI: –61.3, –18.8) and 45.4% (95% CI: –63.7, –17.9), respectively. Unexpectedly, concentrations of ethyl and butyl paraben concentrations increased, although concentrations were low overall and not detected in almost half the samples. Triclosan concentrations decreased by 35.7% (95% CI: –53.3, –11.6), and BP-3 concentrations decreased by 36.0% (95% CI: –51.0, –16.4). Discussion: This study demonstrates that techniques available to consumers, such as choosing personal care products that are labeled to be free of phthalates, parabens, triclosan, and BP-3, can reduce personal exposure to possible endocrine-disrupting chemicals. Involving youth in the design and implementation of the study was key to recruitment, retention, compliance, and acceptability of the intervention. Citation: Harley KG, Kogut K, Madrigal DS, Cardenas M, Vera IA, Meza-Alfaro G, She J, Gavin Q, Zahedi R, Bradman A, Eskenazi B, Parra KL. 2016. Reducing phthalate, paraben, and phenol exposure from personal care

Reducing Phthalate, Paraben, and Phenol Exposure from Personal Care Products in Adolescent Girls: Findings from the HERMOSA Intervention Study.

PubMed

Harley, Kim G; Kogut, Katherine; Madrigal, Daniel S; Cardenas, Maritza; Vera, Irene A; Meza-Alfaro, Gonzalo; She, Jianwen; Gavin, Qi; Zahedi, Rana; Bradman, Asa; Eskenazi, Brenda; Parra, Kimberly L

2016-10-01

Personal care products are a source of exposure to potentially endocrine-disrupting chemicals such as phthalates, parabens, triclosan, and benzophenone-3 (BP-3) for adolescent girls. We enrolled 100 Latina girls in a youth-led, community-based participatory research intervention study to determine whether using personal care products whose labels stated they did not contain these chemicals for 3 days could lower urinary concentrations. Pre- and postintervention urine samples were analyzed for phthalate metabolites, parabens, triclosan, and BP-3 using high-performance liquid chromatography/tandem mass spectrometry. Urinary concentrations of mono-ethyl phthalate (MEP) decreased by 27.4% (95% CI: -39.3, -13.2) on average over the 3-day intervention; no significant changes were seen in urinary concentrations of mono-n-butyl phthalate (MnBP) and mono-isobutyl phthalate (MiBP). Methyl and propyl paraben concentrations decreased by 43.9% (95% CI: -61.3, -18.8) and 45.4% (95% CI: -63.7, -17.9), respectively. Unexpectedly, concentrations of ethyl and butyl paraben concentrations increased, although concentrations were low overall and not detected in almost half the samples. Triclosan concentrations decreased by 35.7% (95% CI: -53.3, -11.6), and BP-3 concentrations decreased by 36.0% (95% CI: -51.0, -16.4). This study demonstrates that techniques available to consumers, such as choosing personal care products that are labeled to be free of phthalates, parabens, triclosan, and BP-3, can reduce personal exposure to possible endocrine-disrupting chemicals. Involving youth in the design and implementation of the study was key to recruitment, retention, compliance, and acceptability of the intervention. Harley KG, Kogut K, Madrigal DS, Cardenas M, Vera IA, Meza-Alfaro G, She J, Gavin Q, Zahedi R, Bradman A, Eskenazi B, Parra KL. 2016. Reducing phthalate, paraben, and phenol exposure from personal care products in adolescent girls: findings from the HERMOSA Intervention Study

A single-blinded, single-centre, controlled study in healthy adult smokers to identify the effects of a reduced toxicant prototype cigarette on biomarkers of exposure and of biological effect versus commercial cigarettes.

PubMed

Shepperd, Christopher J; Newland, Nik; Eldridge, Alison; Graff, Don; Meyer, Ingo

2013-07-29

Despite universal acceptance that smoking is harmful, a substantial number of adults continue to smoke. The development of potential reduced exposure products (more recently termed modified risk tobacco products) has been suggested as a way to reduce the risks of tobacco smoking. This trial is designed to investigate whether changes in toxicant exposure after switching from a commercial to reduced toxicant prototype (RTP) cigarette (7 mg International Organisation for Standardisation (ISO) tar yield) can be assessed by measurement of biomarkers and other factors. The primary objective is to descriptively assess changes in selected biomarkers of exposure (BoE) and biomarkers of biological effect (BoBE) within participants and within and between groups after switching. Secondary objectives are to assess similarly changes in other biomarkers, quality of life, smoking behaviours, physiological measures, mouth-level exposure to toxicants and sensory perception. This trial will assess current smokers, ex-smokers and never-smokers in a single-centre single-blind, controlled clinical trial with a forced-switching design and in-clinic (residential) and ambulatory (non-residential) periods. Smokers will be aged 23-55 years (minimum legal smoking age plus 5 years) and non-smokers 28-55 years (minimum legal smoking age plus 5 years, plus minimum 5 years since last smoked). Smokers will be allowed to smoke freely at all times. We will assess changes in selected BoE and BoBE and effective dose in urine and blood after switching. Creatinine concentrations in serum, creatinine clearance in urine, cotinine concentration in saliva, diaries and collection of spent cigarette filters will be used to assess compliance with the study protocol. Mouth-level exposure to toxins will be assessed by filter analysis. Data from this study are expected to improve scientific understanding of the effects of RTP cigarettes on BoE and BoBE, and give insights into study design for clinical

A single-blinded, single-centre, controlled study in healthy adult smokers to identify the effects of a reduced toxicant prototype cigarette on biomarkers of exposure and of biological effect versus commercial cigarettes

PubMed Central

2013-01-01

Background Despite universal acceptance that smoking is harmful, a substantial number of adults continue to smoke. The development of potential reduced exposure products (more recently termed modified risk tobacco products) has been suggested as a way to reduce the risks of tobacco smoking. This trial is designed to investigate whether changes in toxicant exposure after switching from a commercial to reduced toxicant prototype (RTP) cigarette (7 mg International Organisation for Standardisation (ISO) tar yield) can be assessed by measurement of biomarkers and other factors. The primary objective is to descriptively assess changes in selected biomarkers of exposure (BoE) and biomarkers of biological effect (BoBE) within participants and within and between groups after switching. Secondary objectives are to assess similarly changes in other biomarkers, quality of life, smoking behaviours, physiological measures, mouth-level exposure to toxicants and sensory perception. Methods/design This trial will assess current smokers, ex-smokers and never-smokers in a single-centre single-blind, controlled clinical trial with a forced-switching design and in-clinic (residential) and ambulatory (non-residential) periods. Smokers will be aged 23–55 years (minimum legal smoking age plus 5 years) and non-smokers 28–55 years (minimum legal smoking age plus 5 years, plus minimum 5 years since last smoked). Smokers will be allowed to smoke freely at all times. We will assess changes in selected BoE and BoBE and effective dose in urine and blood after switching. Creatinine concentrations in serum, creatinine clearance in urine, cotinine concentration in saliva, diaries and collection of spent cigarette filters will be used to assess compliance with the study protocol. Mouth-level exposure to toxins will be assessed by filter analysis. Discussion Data from this study are expected to improve scientific understanding of the effects of RTP cigarettes on BoE and BoBE, and

Larval exposure to environmentally relevant mixtures of alkylphenolethoxylates reduces reproductive competence in male fathead minnows

USGS Publications Warehouse

Bistodeau, T.J.; Barber, L.B.; Bartell, S.E.; Cediel, R.A.; Grove, K.J.; Klaustermeier, J.; Woodard, J.C.; Lee, K.E.; Schoenfuss, H.L.

2006-01-01

The ubiquitous presence of nonylphenolethoxylate/octylphenolethoxylate (NPE/OPE) compounds in aquatic environments adjacent to wastewater treatment plants (WWTP) warrants an assessment of the endocrine disrupting potential of these complex mixtures on aquatic vertebrates. In this study, fathead minnow larvae were exposed for 64 days to a mixture of NPE/OPE, which closely models the NPE/OPE composition of a major metropolitan WWTP effluent. Target exposure concentrations included a total NPE/OPE mixture load of 200% of the WWTP effluent concentration (148 ??g/L), 100% of the WWTP effluent concentration (74 ??g/L) and 50% of the WWTP effluent concentration (38 ??g/L). The NPE/OPE mixture contained 0.2% 4-t-octylphenol, 2.8% 4-nonylphenol, 5.1% 4-nonylphenolmonoethoxylate, 9.3% 4-nonylphenoldiethoxylate, 0.9% 4-t-octylphenolmonoethoxylate, 3.1% 4-t-octylphenoldiethoxylate, 33.8% 4-nonylphenolmonoethoxycarboxylate, and 44.8% 4-nonylphenoldiethoxycarboxylate. An additional exposure of 5 ??g/L 4-nonylphenol (nominal) was conducted. The exposure utilized a flow-through system supplied by ground water and designed to deliver consistent concentrations of applied chemicals. Following exposure, larvae were raised to maturity. Upon sexual maturation, exposed male fish were allowed to compete with control males in a competitive spawning assay. Nest holding ability of control and exposed fish was carefully monitored for 7 days. All male fish were then sacrificed and analyzed for plasma vitellogenin, developmental changes in gonadal tissues, alterations in the development of secondary sexual characters, morphometric changes, and changes to reproductive behavior. When exposed to the 200% NPE/OPE treatment most larvae died within the first 4 weeks of exposure. Both the 100% and 50% NPE/OPE exposures caused a significant decrease in reproductive behavior, as indicated by an inability of many of the previously exposed males to acquire and hold a nest site required for reproduction

Human predisposition to cognitive impairment and its relation with environmental exposure to potentially toxic elements.

PubMed

Cabral Pinto, Marina M S; Marinho-Reis, A Paula; Almeida, Agostinho; Ordens, Carlos M; Silva, Maria M V G; Freitas, Sandra; Simões, Mário R; Moreira, Paula I; Dinis, Pedro A; Diniz, M Luísa; Ferreira da Silva, Eduardo A; Condesso de Melo, M Teresa

2017-03-09

New lines of evidence suggest that less than 10% of neurodegenerative diseases have a strict genetic aetiology and other factors may be prevalent. Environmental exposures to potentially toxic elements appear to be a risk factor for Parkinson's, Alzheimer's and sclerosis diseases. This study proposes a multidisciplinary approach combining neurosciences, psychology and environmental sciences while integrating socio-economic, neuropsychological, environmental and health data. We present the preliminary results of a neuropsychological assessment carried out in elderly residents of the industrial city of Estarreja. A battery of cognitive tests and a personal questionnaire were administered to the participants. Multivariate analysis and multiple linear regression analysis were used to identify potential relationships between the cognitive status of the participants and environmental exposure to potentially toxic elements. The results suggest a relationship between urinary PTEs levels and the incidence of cognitive disorders. They also point towards water consumption habits and profession as relevant factors of exposure. Linear regression models show that aluminium (R 2  = 38%), cadmium (R 2  = 11%) and zinc (R 2  = 6%) are good predictors of the scores of the Mini-Mental State Examination cognitive test. Median contents (µg/l) in groundwater are above admissible levels for drinking water for aluminium (371), iron (860), manganese (250), and zinc (305). While the World Health Organization does not provide health-based reference values for aluminium, results obtained from this study suggest that it may have an important role in the cognitive status of the elderly. Urine proved to be a suitable biomarker of exposure both to elements with low and high excretion rates.

High efficiency cabin air filter in vehicles reduces drivers' roadway particulate matter exposures and associated lipid peroxidation

PubMed Central

Shu, Shi; Lin, Yan; She, Jianwen; Ip, Ho Sai Simon; Qiu, Xinghua; Zhu, Yifang

2017-01-01

Commuters who spend long hours on roads are exposed to high levels of traffic related air pollutants (TRAPs). Despite some well-known multiple adverse effects of TRAPs on human health, limited studies have focused on mitigation strategies to reduce these effects. In this study, we measured fine particulate matter (PM2.5) and ultrafine particle (UFP) concentrations inside and outside 17 taxis simultaneously while they were driven on roadways. The drivers’ urinary monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and malondialdehyde (MDA) concentrations just before and right after the driving tests were also determined. Data were collected under three driving conditions (i.e. no mitigation (NM), window closed (WC), and window closed plus using high efficiency cabin air filters (WC+HECA)) for each taxi and driver. The results show that, compared to NM, the WC+HECA reduced in-cabin PM2.5 and UFP concentrations, by 37% and 47% respectively (p < 0.05), whereas the reductions on PAH exposures were insignificant. Although nonsignificant, a reduction of 17% was also observed in the drivers’ urinary MDA under WC+HECA. The MDA concentrations were found to be significantly associated with the in-cabin PM2.5 and UFP concentrations, suggesting the reduction of the drivers’ lipid peroxidation can be at least partially attributed to the PM2.5 and UFP reduction by WC+HECA. Overall, these results suggest HECA filters have potential to reduce particle levels inside taxis and protect drivers’ health. PMID:29176859

High efficiency cabin air filter in vehicles reduces drivers' roadway particulate matter exposures and associated lipid peroxidation.

PubMed

Yu, Nu; Shu, Shi; Lin, Yan; She, Jianwen; Ip, Ho Sai Simon; Qiu, Xinghua; Zhu, Yifang

2017-01-01

Commuters who spend long hours on roads are exposed to high levels of traffic related air pollutants (TRAPs). Despite some well-known multiple adverse effects of TRAPs on human health, limited studies have focused on mitigation strategies to reduce these effects. In this study, we measured fine particulate matter (PM2.5) and ultrafine particle (UFP) concentrations inside and outside 17 taxis simultaneously while they were driven on roadways. The drivers' urinary monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and malondialdehyde (MDA) concentrations just before and right after the driving tests were also determined. Data were collected under three driving conditions (i.e. no mitigation (NM), window closed (WC), and window closed plus using high efficiency cabin air filters (WC+HECA)) for each taxi and driver. The results show that, compared to NM, the WC+HECA reduced in-cabin PM2.5 and UFP concentrations, by 37% and 47% respectively (p < 0.05), whereas the reductions on PAH exposures were insignificant. Although nonsignificant, a reduction of 17% was also observed in the drivers' urinary MDA under WC+HECA. The MDA concentrations were found to be significantly associated with the in-cabin PM2.5 and UFP concentrations, suggesting the reduction of the drivers' lipid peroxidation can be at least partially attributed to the PM2.5 and UFP reduction by WC+HECA. Overall, these results suggest HECA filters have potential to reduce particle levels inside taxis and protect drivers' health.

Study of the effectiveness of a participatory ergonomics intervention in reducing worker pain severity through physical exposure pathways.

PubMed

Laing, Andrew C; Frazer, Mardon B; Cole, Donald C; Kerr, Mickey S; Wells, Richard P; Norman, Robert W

2005-02-01

A participatory ergonomics programme was implemented in an automotive parts manufacturing factory. An ergonomics change team was formed composed of members from management and the organized labour union. It was hypothesized that the physical change projects implemented as part of this process would result in decreased worker exposures to peak and cumulative physical demands and reduced worker perceptions of physical effort and pain severity. A quasi-experimental design was employed, utilizing a sister plant in the corporation as a referent group. A longitudinal questionnaire approach was used to document pre-post changes in worker perceptions. In general, the physical change projects were rated as improvements by workers and were successful at reducing peak and/or cumulative mechanical exposures. However, there were few systematic changes in perceived effort or pain severity levels. Explanations include the confounding effects of differential production rate and staffing changes at the intervention and referent plants and/or insufficient overall intervention intensity due to a relatively short intervention period, plant and team ambivalence towards the process and the low overall impact on exposure of the particular changes implemented.

Potential Role of Pet Cats As a Sentinel Species for Human Exposure to Flame Retardants

PubMed Central

Henríquez-Hernández, Luis A.; Carretón, Elena; Camacho, María; Montoya-Alonso, José Alberto; Boada, Luis D.; Bernal Martín, Verónica; Falcón Cordón, Yaiza; Falcón Cordón, Soraya; Zumbado, Manuel; Luzardo, Octavio P.

2017-01-01

Flame retardants are a wide group of chemicals used by the industry to avoid combustion of materials. These substances are commonly found in plastics, electronic equipment, fabrics, and in many other everyday articles. Subsequently, ubiquitous environmental contamination by these common chemical is frequently reported. In the present study, we have evaluated the level of exposure to polychlorinated biphenyls (PCBs), brominated diphenyl ethers (BDEs), and organophosphorous flame retardants (OPFRs) in pet cats through the analysis of their serum. We also analyzed the level exposure to such chemicals in a series of 20 cat owners, trying to disclose the role of pet cats as sentinel species of human exposure to FRs. Our results showed that PCBs, banned 40 years ago, showed the lowest levels of exposure, followed by BDEs—banned recently. Congeners PCB-138 and PCB-180 were detected in ≥50% of the series, while BDE-47 was detected in near 90% of the pet cats. On the other hand, the highest levels were that of OPFRs, whose pattern of detection was similar to that observed in humans, thus suggesting a potential role of cats as a sentinel species for human exposure to these currently used FRs. Six out of 11 OPFRs determined [2-ethylhexyldiphenyl phosphate, tributylphosphate, triisobutylphosphate, triphenylphosphate, tris (2-chloroethyl) phosphate, and tris (2-chloroisopropyl) phosphate] were detected in 100% of the samples. It will be interesting to perform future studied aimed to elucidating the potential toxicological effects of these highly detected chemicals both, in cats and humans. PMID:28620612

Constitutive melanin density is associated with higher 25-hydroxyvitamin D and potentially total body BMD in older Caucasian adults via increased sun tolerance and exposure.

PubMed

Thompson, M J W; Jones, G; Aitken, D A

2018-06-01

Greater skin pigmentation reduces dose equivalent cutaneous vitamin D3 production, potentially impacting lifetime vitamin D status and fracture risk. We show that melanin density was positively associated with 25-hydroxyvitamin D and total body bone mineral density. These relationships were partially explained by greater sun exposure due to more permissive skin phenotype. Higher cutaneous melanin reduces vitamin D3 production. This may impact lifetime vitamin D status and increase fracture risk. This study aimed to describe the relationship between spectrophotometrically determined constitutive melanin density, osteoporotic risk factors and potential intermediaries in a cohort of exclusively older Caucasian adults. One thousand seventy-two community-dwelling adults aged 50-80 years had constitutive melanin density quantified using spectrophotometry. Sun exposure, skin phenotype, non-melanoma skin cancer (NMSC) prevalence and smoking status were assessed by questionnaire. Bone mineral density (BMD), falls risk, physical activity and 25-hydroxyvitamin D were measured using DXA, the short form Physiological Profile Assessment, pedometer and radioimmunoassay, respectively. Higher melanin density was independently associated with greater ability to tan (RR = 1.27, p < 0.001), less propensity to sunburn (RR = 0.92, p < 0.001), fewer lifetime sunburns (RR = 0.94, p = 0.01), current smoking (RR = 1.41, p < 0.001), female sex (RR = 1.24, p < 0.001) and less photodamage (RR = 0.98, p = 0.01). The associations between melanin density and sun exposure (RR = 1.05-1.11, p < 0.001-0.01), sun protection behaviours (RR = 0.89, p < 0.001) and NMSC prevalence (RR = 0.75, p = 0.001) were no longer significant after taking into account skin phenotype and sun exposure, respectively. 25-Hydroxyvitamin D was strongly associated with higher melanin density (β = 1.71-2.05, p = 0.001). The association between

Application of improved approach to evaluate a community intervention to reduce exposure of young children living in farmworker households to organophosphate pesticides.

PubMed

Griffith, William C; Vigoren, Eric M; Smith, Marissa N; Workman, Tomomi; Thompson, Beti; Coronado, Gloria D; Faustman, Elaine M

2018-04-17

The take-home pathway is a significant source of organophosphate pesticide exposure for young children (3-5 years old) living with an adult farmworker. This avoidable exposure pathway is an important target for intervention. We selected 24 agricultural communities in the Yakima Valley of Washington State and randomly assigned them to receive an educational intervention (n = 12) to reduce children's pesticide exposure or usual care (n = 12). We assessed exposure to pesticides in nearly 200 adults and children during the pre and post-intervention periods by measuring metabolites in urine. We compared pre- and post-intervention exposures by expressing the child's pesticide metabolite concentration as a fraction of the adult's concentration living in the same household, because the amount of pesticides applied during the collection periods varied. Exposures in our community were consistently higher, sometimes above the 95 th percentile of the exposures reported by the National Health and Nutrition Examination Survey (NHANES). While intervention and control communities demonstrated a reduction in the ratio of child to adult exposure, this reduction was more pronounced in intervention communities (2.7-fold, p < 0.001 compared to 1.7-fold, p = 0.052 for intervention and control, respectively). By examining the child/adult biomarker ratio, we demonstrated that our community-based intervention was effective in reducing pesticide exposure to children in agricultural communities.

Mental Health Nurse's Exposure to Workplace Violence Leads to Job Stress, Which Leads to Reduced Professional Quality of Life.

PubMed

Itzhaki, Michal; Bluvstein, Irit; Peles Bortz, Anat; Kostistky, Hava; Bar Noy, Dor; Filshtinsky, Vivian; Theilla, Miriam

2018-01-01

Professional quality of life (ProQOL) reflects how individuals feel about their work as helpers. Psychiatric ward nurses cope with significant psychological and physical challenges, including exposure to verbal and physical violence. This study was based on two aspects of ProQOL, the positive compassion satisfaction, and the negative compassion fatigue, with the aim of investigating the relation of ProQOL to job stress and violence exposure at a large mental health center. Data were collected from 114 mental health nurses (49/63 M/F) who completed a self-administered questionnaire examining violence exposure, ProQOL, and job stress. The results showed that during the last year, almost all nurses (88.6%) experienced verbal violence, and more than half (56.1%) experienced physical violence. Only 2.6% experienced no violence. ProQOL was not associated with violence exposure but was reduced by work stress and by previous exposure to violence; nurses who perceived their work as more stressful had lower satisfaction from their work. In conclusion, although most mental health nurses are exposed to physical and verbal violence, their ProQOL is more related to job stress than to workplace violence (WPV). Hospital managements should conduct work stress reduction intervention programs and promote strategizes to reduce WPV. Further exploration of (a) factors affecting ProQOL and (b) the effect of violence coping workshops on ProQOL is warranted.

Reduced Exercise Tolerance and Pulmonary Capillary Recruitment with Remote Secondhand Smoke Exposure

PubMed Central

Arjomandi, Mehrdad; Haight, Thaddeus; Sadeghi, Nasrat; Redberg, Rita; Gold, Warren M.

2012-01-01

Rationale Flight attendants who worked on commercial aircraft before the smoking ban in flights (pre-ban FAs) were exposed to high levels of secondhand smoke (SHS). We previously showed never-smoking pre-ban FAs to have reduced diffusing capacity (Dco) at rest. Methods To determine whether pre-ban FAs increase their Dco and pulmonary blood flow () during exercise, we administered a symptom-limited supine-posture progressively increasing cycle exercise test to determine the maximum work (watts) and oxygen uptake () achieved by FAs. After 30 min rest, we then measured Dco and at 20, 40, 60, and 80 percent of maximum observed work. Results The FAs with abnormal resting Dco achieved a lower level of maximum predicted work and compared to those with normal resting Dco (mean±SEM; 88.7±2.9 vs. 102.5±3.1%predicted ; p = 0.001). Exercise limitation was associated with the FAs' FEV1 (r = 0.33; p = 0.003). The Dco increased less with exercise in those with abnormal resting Dco (mean±SEM: 1.36±0.16 vs. 1.90±0.16 ml/min/mmHg per 20% increase in predicted watts; p = 0.020), and amongst all FAs, the increase with exercise seemed to be incrementally lower in those with lower resting Dco. Exercise-induced increase in was not different in the two groups. However, the FAs with abnormal resting Dco had less augmentation of their Dco with increase in during exercise (mean±SEM: 0.93±0.06 vs. 1.47±0.09 ml/min/mmHg per L/min; p<0.0001). The Dco during exercise was inversely associated with years of exposure to SHS in those FAs with ≥10 years of pre-ban experience (r = −0.32; p = 0.032). Conclusions This cohort of never-smoking FAs with SHS exposure showed exercise limitation based on their resting Dco. Those with lower resting Dco had reduced pulmonary capillary recruitment. Exposure to SHS in the aircraft cabin seemed to be a predictor for lower Dco during exercise. PMID:22493689

How effectively do horizontal and vertical response strategies of long-finned pilot whales reduce sound exposure from naval sonar?

PubMed

Wensveen, Paul J; von Benda-Beckmann, Alexander M; Ainslie, Michael A; Lam, Frans-Peter A; Kvadsheim, Petter H; Tyack, Peter L; Miller, Patrick J O

2015-05-01

The behaviour of a marine mammal near a noise source can modulate the sound exposure it receives. We demonstrate that two long-finned pilot whales both surfaced in synchrony with consecutive arrivals of multiple sonar pulses. We then assess the effect of surfacing and other behavioural response strategies on the received cumulative sound exposure levels and maximum sound pressure levels (SPLs) by modelling realistic spatiotemporal interactions of a pilot whale with an approaching source. Under the propagation conditions of our model, some response strategies observed in the wild were effective in reducing received levels (e.g. movement perpendicular to the source's line of approach), but others were not (e.g. switching from deep to shallow diving; synchronous surfacing after maximum SPLs). Our study exemplifies how simulations of source-whale interactions guided by detailed observational data can improve our understanding about motivations behind behaviour responses observed in the wild (e.g., reducing sound exposure, prey movement). Copyright © 2015 Elsevier Ltd. All rights reserved.

Meeting report: international workshop on endocrine disruptors: exposure and potential impact on consumers health.

PubMed

Rousselle, C; Ormsby, J N; Schaefer, B; Lampen, A; Platzek, T; Hirsch-Ernst, K; Warholm, M; Oskarsson, A; Nielsen, P J; Holmer, M L; Emond, C

2013-02-01

The French Agency for Food, Environmental and Occupational Health and Safety (Anses) hosted a two-day workshop on Endocrine Disruptors: Exposure and Potential Impact on Consumers Health, bringing together participants from international organizations, academia, research institutes and from German, Swedish, Danish and French governmental agencies. The main objective of the workshop was to share knowledge and experiences on endocrine disruptors (ED) exposure and potential impact on consumers' health, to identify current risk assessment practices and knowledge gaps and issue recommendations on research needs and future collaboration. The following topics were reviewed: (1) Definition of ED, (2) endpoints to be considered for Risk assessment (RA) of ED, (3) non-monotonic dose response curves, (4) studies to be considered for RA (regulatory versus academic studies), (5) point of departure and uncertainty factors, (6) exposure assessment, (7) regulatory issues related to ED. The opinions expressed during this workshop reflect day-to-day experiences from scientists, regulators, researchers, and others from many different countries in the fields of risk assessment, and were regarded by the attendees as an important basis for further discussions. Accordingly, the participants underlined the need for more exchange in the future to share experiences and improve the methodology related to risk assessment for endocrine disrupters. Copyright © 2012 Elsevier Inc. All rights reserved.

SHEDS-HT: An Integrated Probabilistic Exposure Model for ...

EPA Pesticide Factsheets

United States Environmental Protection Agency (USEPA) researchers are developing a strategy for highthroughput (HT) exposure-based prioritization of chemicals under the ExpoCast program. These novel modeling approaches for evaluating chemicals based on their potential for biologically relevant human exposures will inform toxicity testing and prioritization for chemical risk assessment. Based on probabilistic methods and algorithms developed for The Stochastic Human Exposure and Dose Simulation Model for Multimedia, Multipathway Chemicals (SHEDS-MM), a new mechanistic modeling approach has been developed to accommodate high-throughput (HT) assessment of exposure potential. In this SHEDS-HT model, the residential and dietary modules of SHEDS-MM have been operationally modified to reduce the user burden, input data demands, and run times of the higher-tier model, while maintaining critical features and inputs that influence exposure. The model has been implemented in R; the modeling framework links chemicals to consumer product categories or food groups (and thus exposure scenarios) to predict HT exposures and intake doses. Initially, SHEDS-HT has been applied to 2507 organic chemicals associated with consumer products and agricultural pesticides. These evaluations employ data from recent USEPA efforts to characterize usage (prevalence, frequency, and magnitude), chemical composition, and exposure scenarios for a wide range of consumer products. In modeling indirec

The Potential of Pre-Exposure Prophylaxis for Women in Violent Relationships.

PubMed

Braksmajer, Amy; Senn, Theresa E; McMahon, James

2016-06-01

HIV and intimate partner violence (IPV) are significant intersecting threats to women's health. Women in violent relationships have few feasible HIV risk reduction options as traditional prevention methods are largely dependent on a partner's cooperation. The purpose of this review is to explore potential benefits and drawbacks of pre-exposure prophylaxis (PrEP) use among women in the United States experiencing IPV. Advantages of PrEP use in this population include the potential for covert or autonomous use, coital independence, dual protection against sexual and injection risk, and facilitated connections to social services. A number of barriers, however, may interfere with the effective use of PrEP, including partner resistance, cost, frequent medical visits, gendered norms regarding sexuality, and stigma. To realize its potential for women in violent relationships, it will be necessary to incorporate PrEP into behavioral and structural interventions that encourage uptake, facilitate adherence, ensure women's safety, and challenge existing gender norms.

Reduced cardiovascular fitness associated with exposure to clozapine in individuals with chronic schizophrenia.

PubMed

Kim, David D; Lang, Donna J; Procyshyn, Ric M; Woodward, Melissa L; Kaufman, Kai; White, Randall F; Honer, William G; Warburton, Darren E R

2018-04-01

Studies show that individuals with schizophrenia have impaired cardiovascular fitness (i.e., low peak aerobic power (VO 2 peak)). It is speculated that antipsychotics with adverse cardiovascular and metabolic profiles, in particular clozapine, have a significant impact on VO 2 peak. In this cross-sectional study, we examined whether exposure to clozapine was associated with further reduced VO 2 peak compared with non-clozapine antipsychotics. Thirty participants with chronic schizophrenia or schizoaffective disorder were divided into clozapine and non-clozapine groups. Mean daily doses of antipsychotics were standardized to chlorpromazine equivalents and haloperidol equivalents for antagonism of alpha 1 - and alpha 2 -adrenergic receptors. Participants completed an incremental-to-maximal symptom-limited exercise test on a cycle ergometer for the assessment of VO 2 peak. The clozapine group demonstrated significantly lower VO 2 peak than the non-clozapine group. Haloperidol equivalents for alpha-adrenergic receptor antagonism, but not chlorpromazine equivalents, demonstrated significant inverse associations with VO 2 peak. The clozapine group had a significantly higher amount of antagonistic activity at alpha-adrenergic receptors than the non-clozapine group. In conclusion, exposure to clozapine was associated with further reduced cardiovascular fitness, which may be explained by the drug's greater antagonistic activity at alpha-adrenergic receptors. Cardiovascular fitness needs to be promoted in individuals treated with antipsychotics, particularly clozapine, to prevent the risk of cardiovascular disease and mortality. Copyright © 2018 Elsevier B.V. All rights reserved.

Does Media Literacy Mitigate Risk for Reduced Body Satisfaction Following Exposure to Thin-Ideal Media?

PubMed

McLean, Siân A; Paxton, Susan J; Wertheim, Eleanor H

2016-08-01

Exposure to thin-ideal media can contribute to increased body dissatisfaction in adolescent girls. Understanding the factors that may prevent or exacerbate the negative effects of media exposure on body dissatisfaction is important to facilitate prevention of these problems. This study evaluated the effects of exposure to thin-ideal media images on body image in three instructional set experimental conditions: appearance comparison, peer norms, and control. An important aim was to examine baseline levels of media literacy as a protective factor and trait thin-ideal internalization and trait upward appearance comparison as risk factors. Early adolescent girls (N = 246) completed baseline measures and 1 week later viewed thin-ideal media images, before and after which they rated their state body satisfaction. Participants in the appearance comparison instruction but not peer norms instruction condition had significantly reduced body satisfaction. Media literacy, particularly high levels of critical thinking, mitigated the negative effects of trait thin-ideal internalization and trait upward appearance comparison on body satisfaction outcomes. These findings provide evidence for the role of media literacy as a protective factor against the negative effects on body satisfaction of exposure to thin-ideal media images, and also provide evidence to support the development and implementation of media literacy-based body image interventions.

Forecast-based Interventions Can Reduce the Health and Economic Burden of Wildfires

EPA Science Inventory

We simulated public health forecast-based interventions during a wildfire smoke episode in rural North Carolina to show the potential for use of modeled smoke forecasts toward reducing the health burden and showed a significant economic benefit of reducing exposures. Daily and co...

Lung cancer deaths from indoor radon and the cost effectiveness and potential of policies to reduce them

PubMed Central

Read, Simon; McGale, Paul; Darby, Sarah

2009-01-01

Objective To determine the number of deaths from lung cancer related to radon in the home and to explore the cost effectiveness of alternative policies to control indoor radon and their potential to reduce lung cancer mortality. Design Cost effectiveness analysis. Setting United Kingdom. Data sources Epidemiological data on risks from indoor radon and from smoking, vital statistics on deaths from lung cancer, survey information on effectiveness and costs of radon prevention and remediation. Main outcome measures Estimated number of deaths from lung cancer related to indoor radon, lifetime risks of death from lung cancer before and after various potential interventions to control radon, the cost per quality adjusted life year (QALY) gained from different policies for control of radon, and the potential of those policies to reduce lung cancer mortality. Results The mean radon concentration in UK homes is 21 becquerels per cubic metre (Bq/m3). Each year around 1100 deaths from lung cancer (3.3% of all deaths from lung cancer) are related to radon in the home. Over 85% of these arise from radon concentrations below 100 Bq/m3 and most are caused jointly by radon and active smoking. Current policy requiring basic measures to prevent radon in new homes in selected areas is highly cost effective, and such measures would remain cost effective if extended to the entire UK, with a cost per QALY gained of £11 400 ( €12 200; $16 913). Current policy identifying and remediating existing homes with high radon levels is, however, neither cost effective (cost per QALY gained £36 800) nor effective in reducing lung cancer mortality. Conclusions Policies requiring basic preventive measures against radon in all new homes throughout the UK would be cost effective and could complement existing policies to reduce smoking. Policies involving remedial work on existing homes with high radon levels cannot prevent most radon related deaths, as these are caused by moderate exposure

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion.

PubMed

Wilson, Jordan L; Samaranayake, V A; Limmer, Matt A; Burken, Joel G

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman's correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with minimal

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion

USGS Publications Warehouse

Wilson, Jordan L.; Samaranayake, V.A.; Limmer, Matthew A.; Burken, Joel G.

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman’s correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion

PubMed Central

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman’s correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with

Splitting blood and blood product packaging reduces donor exposure for patients undergoing cardiopulmonary bypass.

PubMed

Nuszkowski, M M; Jonas, R A; Zurakowski, D; Deutsch, N

2015-11-01

Cardiopulmonary bypass for congenital heart surgery requires packed red cells (PRBC) and fresh frozen plasma (FFP) to be available, both for priming of the circuit as well as to replace blood loss. This study examines the hypothesis that splitting one unit of packed red blood cells and one unit of fresh frozen plasma into two half units reduces blood product exposure and wastage in the Operating Room. Beginning August 2013, the blood bank at Children's National Medical Center began splitting one unit of packed red blood cells (PRBC) and one unit of fresh frozen plasma (FFP) for patients undergoing cardiopulmonary bypass (CPB). The 283 patients who utilized CPB during calendar year 2013 were divided into 2 study groups: before the split and after the split. The principal endpoints were blood product usage and donor exposure intra-operatively and within 72 hours post-operatively. There was a significant decrease in median total donor exposures for FFP and cryoprecipitate from 5 to 4 per case (p = 0.007, Mann-Whitney U-test). However, there was no difference in the volume of blood and blood products used; in fact, there was a significant increase in the amount of FFP that was wasted with the switch to splitting the unit of FFP. We found that modification of blood product packaging can decrease donor exposure. Future investigation is needed as to how to modify packaging to minimize wastage. © The Author(s) 2015.

Interactive effects of hypoxia and PCB co-exposure on expression of CYP1A and its potential regulators in Atlantic croaker liver.

PubMed

Rahman, Md Saydur; Thomas, Peter

2018-04-01

Although marine and coastal environments which are contaminated with xenobiotic organic compounds often become hypoxic during the summer, the interactive effects of hypoxia and xenobiotic exposure on marine species such as teleost fishes remain poorly understood. The expression and activity of monooxygenase enzyme cytochrome P450-1A (CYP1A) in fishes are upregulated by exposure to polychlorinated biphenyls (PCBs), whereas they are down-regulated during hypoxia exposure. We investigated the interactive effects of hypoxia and PCB co-exposure on hepatic CYP1A expression in Atlantic croaker and on potential regulators of CYP1A. Croaker were exposed to hypoxia (1.7 mg/L dissolved oxygen), 3,3',4,4'-tetrachlorobiphenyl (PCB 77, dose: 2 and 8 µg/g body weight), and Aroclor 1254 (a common PCB mixture, dose: 0.5 and 1 µg/g body weight), alone and in combination for 4 weeks. PCB 77 exposure markedly increased hepatic CYP1A mRNA and protein expression, and ethoxyresorufin-O-deethylase (EROD, an indicator of CYP1A enzyme) activity and increased endothelial nitric oxide synthase (eNOS) protein expression. PCB 77 treatment also increased interleukin-1β (IL-1β, a cytokine) mRNA levels and protein carbonyl (PC, an indicator of reactive oxygen species, ROS) contents. These marked PCB 77- and Aroclor 1254-induced increases in CYP1A mRNA levels and EROD activity were significantly attenuated by co-exposure to hypoxia, whereas the increases in hepatic eNOS protein and IL-1β mRNA expression, and PC contents were augmented by hypoxia co-exposure. The results suggest that biotransformation of organic xenobiotics by CYP1A is reduced in fish during co-exposure to hypoxia and is accompanied by alterations in eNOS, ROS, and IL-1β levels. © 2018 Wiley Periodicals, Inc.

Low-amplitude, high-frequency electromagnetic field exposure causes delayed and reduced growth in Rosa hybrida.

PubMed

Grémiaux, Alexandre; Girard, Sébastien; Guérin, Vincent; Lothier, Jérémy; Baluška, František; Davies, Eric; Bonnet, Pierre; Vian, Alain

2016-01-15

It is now accepted that plants perceive high-frequency electromagnetic field (HF-EMF). We wondered if the HF-EMF signal is integrated further in planta as a chain of reactions leading to a modification of plant growth. We exposed whole small ligneous plants (rose bush) whose growth could be studied for several weeks. We performed exposures at two different development stages (rooted cuttings bearing an axillary bud and 5-leaf stage plants), using two high frequency (900MHz) field amplitudes (5 and 200Vm(-1)). We achieved a tight control on the experimental conditions using a state-of-the-art stimulation device (Mode Stirred Reverberation Chamber) and specialized culture-chambers. After the exposure, we followed the shoot growth for over a one-month period. We observed no growth modification whatsoever exposure was performed on the 5-leaf stage plants. When the exposure was performed on the rooted cuttings, no growth modification was observed on Axis I (produced from the elongation of the axillary bud). Likewise, no significant modification was noted on Axis II produced at the base of Axis I, that came from pre-formed secondary axillary buds. In contrast, Axis II produced at the top of Axis I, that came from post-formed secondary buds consistently displayed a delayed and significant reduced growth (45%). The measurements of plant energy uptake from HF-EMF in this exposure condition (SAR of 7.2 10(-4)Wkg(-1)) indicated that this biological response is likely not due to thermal effect. These results suggest that exposure to electromagnetic field only affected development of post-formed organs. Copyright © 2015 Elsevier GmbH. All rights reserved.

Modeling potential occupational inhalation exposures and associated risks of toxic organics from chemical storage tanks used in hydraulic fracturing using AERMOD.

PubMed

Chen, Huan; Carter, Kimberly E

2017-05-01

Various toxic chemicals used in hydraulic fracturing fluids may influence the inherent health risks associated with these operations. This study investigated the possible occupational inhalation exposures and potential risks related to the volatile organic compounds (VOCs) from chemical storage tanks and flowback pits used in hydraulic fracturing. Potential risks were evaluated based on radial distances between 5 m and 180 m from the wells for 23 contaminants with known inhalation reference concentration (RfC) or inhalation unit risks (IUR). Results show that chemicals used in 12.4% of the wells posed a potential acute non-cancer risks for exposure and 0.11% of the wells with may provide chronic non-cancer risks for exposure. Chemicals used in 7.5% of the wells were associated with potential acute cancer risks for exposure. Those chemicals used in 5.8% of the wells may be linked to chronic cancer risks for exposure. While eight organic compounds were associated with acute non-cancer risks for exposure (>1), methanol the major compound in the chemical storage tanks (1.00-45.49) in 7,282 hydraulic fracturing wells. Wells with chemicals additives containing formaldehyde exhibited both acute and chronic cancer risks for exposure with IUR greater than 10 -6 , suggesting formaldehyde was the dominant contributor to both types of risks for exposure in hydraulic fracturing. This study also found that due to other existing on-site emission sources of VOCs and the geographically compounded air concentrations from other surrounding wells, chemical emissions data from storage tanks and flowback pits used in this study were lower than reported concentrations from field measurements where higher occupational inhalation risks for exposure may be expected. Copyright © 2017 Elsevier Ltd. All rights reserved.

Di-isoheptyl Phthalate (DIHP) in utero exposure reduces testicular testosterone (T) production in fetal Sprague Dawley (SD) rats

EPA Science Inventory

Exposure to DIHP, a commercial phthalate ester plasticizer used in flooring manufacturing, during the fetal period of sexual differentiation disrupts male reproductive development resulting in reproductive malformations and reduced androgen-dependent reproductive tissue weights i...

Air pollution exposure potentiates hypertension through reactive oxygen species-mediated activation of Rho/ROCK

EPA Science Inventory

OBJECTIVE: Fine particulate matter <2.5 microm (PM2.5) has been implicated in vasoconstriction and potentiation of hypertension in humans. We investigated the effects of short-term exposure to PM2.5 in the angiotensin II (AII) infusion model. METHODS AND RESULTS: Sprague-Dawley r...

Setting Up a Patient Care Call Center After Potential HCV Exposure.

PubMed

Friedman, Candace; Bucholz, Brigette; Anderson, Susan G; Dwyer, Shon A; Aguirre, Josephine

2016-09-01

Notify patients of a potential exposure to hepatitis C virus, coordinate testing, and provide follow-up counseling. A team was convened to identify various needs in developing a patient care call center. The areas addressed included the following: location, hours, and duration; telephone accessibility; tracking calls and test results; billing; staffing; notification; and potential issues requiring additional evaluation. Disclosure letters were sent to 1275 patients; 57 letters were not deliverable. There were 245 calls to the helpline from October 25 through November 15. Lessons learned centered on hours of availability, staffing, use of an automated phone system and email communication, tracking results, and billing issues. A successful patient notification and follow-up effort requires a multidisciplinary team, internal and external communication, collection of data over an extended period, and coordination of patient information.

High-fat enteral nutrition reduces intestinal mucosal barrier damage after peritoneal air exposure.

PubMed

Tan, Shan-Jun; Yu, Chao; Yu, Zhen; Lin, Zhi-Liang; Wu, Guo-Hao; Yu, Wen-Kui; Li, Jie-Shou; Li, Ning

2016-05-01

Peritoneal air exposure is needed in open abdominal surgery, but long-time exposure could induce intestinal mucosal barrier dysfunction followed by many postoperative complications. High-fat enteral nutrition can ameliorate intestinal injury and improve intestinal function in many gastrointestinal diseases. In the present study, we investigated the effect of high-fat enteral nutrition on intestinal mucosal barrier after peritoneal air exposure and the underlying mechanism. Male adult rats were administrated saline, low-fat or high-fat enteral nutrition via gavage before and after peritoneal air exposure for 3 h. Rats undergoing anesthesia without laparotomy received saline as control. Twenty four hours after surgery, samples were collected to assess intestinal mucosal barrier changes in serum D-lactate levels, intestinal permeability, intestinal tight junction protein ZO-1 and occludin levels, and intestinal histopathology. The levels of malondialdehyde and the activity of superoxide dismutase in the ileum tissue were also measured to assess the status of intestinal oxidative stress. High-fat enteral nutrition significantly decreased the serum D-lactate level and increased the intestinal tight junction protein ZO-1 level when compared to the group treated with low-fat enteral nutrition (P < 0.05). Meanwhile, histopathologic findings showed that the intestinal mucosal injury assessed by the Chiu's score and the intestinal epithelial tight junction were also improved much more in the high-fat enteral nutrition-treated group (P < 0.05). In addition, the intestinal malondialdehyde level was lower, and the intestinal superoxide dismutase activity was higher in the high-fat enteral nutrition-treated group than that in the low-fat enteral nutrition-treated group (P < 0.05). These results suggest that high-fat enteral nutrition could reduce intestinal mucosal barrier damage after peritoneal air exposure, and the underlying mechanism may be associated with its antioxidative

An evaluation of potential occupational exposure to asbestiform amphiboles near a former vermiculite mine.

PubMed

Hart, Julie F; Spear, Terry M; Ward, Tony J; Baldwin, Caitlan E; Salo, Marissa N; Elashheb, Mohamed I

2009-01-01

Amphibole asbestos (AA) has been detected on the surface of tree bark in forests neighboring an abandoned vermiculite mine near Libby, Montana. In the present study, simulations were performed to assess potential AA exposure associated with United States Department of Agriculture Forest Service (FS) occupational activities. Bark samples were collected prior, and personal breathing zone (PBZ) and Tyvek clothing wipe samples were collected during and immediately after trials that simulated FS activities. Transmission electron microscopy (TEM) analyses revealed AA bark concentrations up to 15 million structures per square centimeter (s/cm(2)). AA was detected in 25% of the PBZ TEM samples. AA was detected on wipe samples collected from all activities evaluated. This research demonstrates the potential for airborne exposure and transport of AA in the Kootenai National Forest. These findings are especially relevant to those that work in the area and to the general public who may conduct recreational activities.

Human exposure to neonicotinoid insecticides and the evaluation of their potential toxicity: An overview.

PubMed

Han, Wenchao; Tian, Ying; Shen, Xiaoming

2018-02-01

Neonicotinoid insecticides have become the fastest growing class of insecticides over the past few decades. The insecticidal activity of neonicotinoids is attributed to their agonist action on nicotinic acetylcholine receptors (nAChRs). Because of the special selective action on nAChRs in central nervous system of insects, and versatility in application methods, neonicotinoids are used to protect crops and pets from insect attacks globally. Although neonicotinoids are considered low toxicity to mammals and humans in comparison with traditional insecticides, more and more studies show exposure to neonicotinoids pose potential risk to mammals and even humans. In recent years, neonicotinoids and their metabolites have been successfully detected in various human biological samples. Meanwhile, many studies have focused on the health effects of neonicotinoids on humans. Our aims here are to review studies on human neonicotinoid exposure levels, health effect, evaluation of potential toxicity and to suggest possible directions for future research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Potential for Inhalation Exposure to Engineered Nanoparticles from Nanotechnology-Based Cosmetic Powders

PubMed Central

Nazarenko, Yevgen; Zhen, Huajun; Han, Taewon; Lioy, Paul J.

2012-01-01

Background: The market of nanotechnology-based consumer products is rapidly expanding, and the lack of scientific evidence describing the accompanying exposure and health risks stalls the discussion regarding its guidance and regulation. Objectives: We investigated the potential for human contact and inhalation exposure to nanomaterials when using nanotechnology-based cosmetic powders and compare them with analogous products not marketed as nanotechnology based. Methods: We characterized the products using transmission electron microscopy (TEM) and laser diffraction spectroscopy and found nanoparticles in five of six tested products. TEM photomicrographs showed highly agglomerated states of nanoparticles in the products. We realistically simulated the use of cosmetic powders by applying them to the face of a human mannequin head while simultaneously sampling the released airborne particles through the ports installed in the mannequin’s nostrils. Results: We found that a user would be exposed to nanomaterial predominantly through nanoparticle-containing agglomerates larger than the 1–100-nm aerosol fraction. Conclusions: Predominant deposition of nanomaterial(s) will occur in the tracheobronchial and head airways—not in the alveolar region as would be expected based on the size of primary nanoparticles. This could potentially lead to different health effects than expected based on the current understanding of nanoparticle behavior and toxicology studies for the alveolar region. PMID:22394622

Short term effects of reduced exposure to cigarette smoke on white blood cells, platelets and red blood cells in adult cigarette smokers.

PubMed

Roethig, Hans J; Koval, Tamara; Muhammad-Kah, Raheema; Jin, Yan; Mendes, Paul; Unverdorben, Martin

2010-01-01

Previous studies indicate that cigarette smokers have a 5-30% higher white blood cell counts (WBC) compared to non-smokers and higher red blood cell counts. This study was to pool hematology data from three similar studies and analyze the data for effects on WBC, its subpopulations, platelets, red blood cell count (RBC) and hematocrit in adult cigarette smokers three days after using an electrically heated cigarette smoking system (EHCSS) as a potential reduced exposure product (PREP) or no-smoking compared to smoking a conventional cigarette. Lower exposure to cigarette smoke in adult, long term smokers, by using an EHCSS or stopping smoking, leads to statistically significant decreases of up to 9% in WBC, neutrophils, lymphocytes, platelets, RBC and hematocrit within three days. Switching from CC-smoking to EHCSS-smoking or no-smoking resulted in lower WBC and vice versa within 3 days. This clinical model may be used as a screening tool to find new technologies that could provide insights on changes in inflammation resulting from the change in cigarette smoke. Copyright 2010 Elsevier Inc. All rights reserved.

Right to know: reducing risks of fecal pathogen exposure for ED patients and staff.

PubMed

Delaney, Molly Bridget

2014-07-01

The purpose of this article is to review the literature regarding the multiple challenges that contribute to ED bedside toileting and examine best practices that will reduce fecal exposure, cross-contamination among patients, and employee splash injuries. We searched the Cumulative Index to Nursing and Allied Health Literature, MEDLINE, and Cochrane database for information about the multiple challenges involved in bedside toileting, using the following search terms: bedside toileting, gastroenteritis, macerator, sluice machine, fecal pathogen exposure, and splash injury. In addition, costs and benefits of reusable versus disposable bedside toileting equipment were compared and contrasted. Emergency departments have a higher exposure rate to fecal pathogens with current methods of bedside toileting. Short incubation periods may not allow the proper lead time needed for patients to access primary care providers. As a result, emergency departments and urgent care centers become a likely point of entry into the health care system. Although most inpatient rooms have built-in bathrooms, most emergency departments and outpatient examination rooms do not. Although many patients are ambulatory, restrictive monitoring equipment is required. For safety reasons, staff must bring toileting equipment to the bedsides of both ambulatory and non-ambulatory patients. Hopper dependence creates longer walking distances and delays. These delays may lead to incontinence events, skin breakdown, more frequent bed changes, and higher linen and labor costs. Reusable bedside toileting equipment is associated with at-risk behaviors. Examples are procrastination and sanitization shortcuts. These behaviors risk cross-contamination of patients especially when urgent situations require equipment to be reused in the interim. ED patients and staff are 5 times more likely to undergo fecal exposure. The 5 phases of ED bedside toileting at which risks occur are as follows: equipment setup, transport

Potential Surgical Exposure of the Parapharyngeal Internal Carotid Artery by Endonasal, Transoral, and Transcervical Approaches.

PubMed

Tanjararak, Kangsadarn; Upadhyay, Smita; Thiensri, Thanakorn; Muto, Jun; Roongpuvapaht, Boonsam; Prevedello, Daniel M; Carrau, Ricardo L

2018-06-01

Objectives  Endoscopic and endoscopic-assisted approaches to the parapharyngeal space have been reported; however, their potential for vascular exposure has not been previously assessed. This study aims to compare the potential exposure and control of the parapharyngeal internal carotid artery (ppICA) via various approaches. Design and Main Outcome Measures  Ten cadaveric specimens were dissected bilaterally, exposing the ppICA via endonasal, transoral, and transcervical approaches. Length of the exposed vessel and potential control were assessed (feasibility and time required to place an encircling suture). Results  Endoscopic transoral and transcervical-transmandibular approaches expose a significantly longer segment of the ppICA (6.89 and 7.09 cm) than the transoral and endonasal approaches. Vascular control was achieved via endoscopic-endonasal, endoscopic-transoral, and open techniques in 121.6, 64.8, and 5.2 seconds, respectively. Conclusion  Histopathology, goals of surgery, and familiarity of the surgeon with each technique may ultimately determine the choice of approach; however, this study suggests that exposure of the ppICA by endoscopic-assisted transoral approach is comparable to that of a transcervical-transmandibular approach. Vascular control was feasible under elective circumstances. However, the difficulty varied widely, potentially reflecting the challenges of controlling an injured ppICA. However, one must note that active bleeding obscures the surgical field in ways that may impair ppICA control. Furthermore, the results may not reflect clinical scenarios where tumor distorts the surgical field. Nonetheless, the study suggests that, in properly selected patients, the endoscopic-assisted transoral approach avoids problems associated with unsightly scars, mandibular osteotomy, and facial nerve manipulation, whereas, the transcervical-transmandibular approach offers the swiftest vascular control.

Poisoning following exposure to chemicals stored in mislabelled or unlabelled containers: a recipe for potential disaster.

PubMed

Millard, Yvette C; Slaughter, Robin J; Shieffelbien, Lucy M; Schep, Leo J

2014-09-26

To investigate poisoning exposures to chemicals that were unlabelled, mislabelled or not in their original containers in New Zealand over the last 10 years, based on calls to the New Zealand National Poisons Centre (NZNPC). Call data from the NZNPC between 2003 and 2012 were analysed retrospectively. Parameters reviewed included patient age, route and site of exposure, product classification and recommended intervention. Of the 324,411 calls received between 2003 and 2012, 100,465 calls were associated with acute human exposure to chemicals. There were 757 inquiries related to human exposure to mislabelled or unlabelled chemicals consisting of 0.75% of chemical exposures. Adults were involved in 51% of incidents, children, <5 years 32%, 5-10 years 10%, and adolescents 5%. Child exploratory behaviour was responsible for 38% of calls and adult unintentional exposures 61%. Medical attention was advised in 26% of calls. Inadvertent exposure to toxic products stored in unlabelled or mislabelled containers is a problem for all age groups. Although it represents a small proportion of total calls to the NZNPC it remains a potential risk for serious poisoning. It is important that chemicals are stored securely, in their original containers, and never stored in drinking vessels.

Evaluation of ionic air purifiers for reducing aerosol exposure in confined indoor spaces.

PubMed

Grinshpun, S A; Mainelis, G; Trunov, M; Adhikari, A; Reponen, T; Willeke, K

2005-08-01

Numerous techniques have been developed over the years for reducing aerosol exposure in indoor air environments. Among indoor air purifiers of different types, ionic emitters have gained increasing attention and are presently used for removing dust particles, aeroallergens and airborne microorganisms from indoor air. In this study, five ionic air purifiers (two wearable and three stationary) that produce unipolar air ions were evaluated with respect to their ability to reduce aerosol exposure in confined indoor spaces. The concentration decay of respirable particles of different properties was monitored in real time inside the breathing zone of a human manikin, which was placed in a relatively small (2.6 m3) walk-in chamber during the operation of an ionic air purifier in calm air and under mixing air condition. The particle removal efficiency as a function of particle size was determined using the data collected with a size-selective optical particle counter. The removal efficiency of the more powerful of the two wearable ionic purifiers reached about 50% after 15 min and almost 100% after 1.5 h of continuous operation in the chamber under calm air conditions. In the absence of external ventilation, air mixing, especially vigorous one (900 CFM), enhanced the air cleaning effect. Similar results were obtained when the manikin was placed inside a partial enclosure that simulated an aircraft seating configuration. All three stationary ionic air purifiers tested in this study were found capable of reducing the aerosol concentration in a confined indoor space. The most powerful stationary unit demonstrated an extremely high particle removal efficiency that increased sharply to almost 90% within 5-6 min, reaching about 100% within 10-12 min for all particle sizes (0.3-3 microm) tested in the chamber. For the units of the same emission rate, the data suggest that the ion polarity per se (negative vs. positive) does not affect the performance but the ion emission rate

Inhalation exposure during spray application and subsequent sanding of a wood sealant containing zinc oxide nanoparticles.

PubMed

Cooper, Michael R; West, Gavin H; Burrelli, Leonard G; Dresser, Daniel; Griffin, Kelsey N; Segrave, Alan M; Perrenoud, Jon; Lippy, Bruce E

2017-07-01

Nano-enabled construction products have entered into commerce. There are concerns about the safety of manufactured nanomaterials, and exposure assessments are needed for a more complete understanding of risk. This study assessed potential inhalation exposure to ZnO nanoparticles during spray application and power sanding of a commercially available wood sealant and evaluated the effectiveness of local exhaust ventilation in reducing exposure. A tradesperson performed the spraying and sanding inside an environmentally-controlled chamber. Dust control methods during sanding were compared. Filter-based sampling, electron microscopy, and real-time particle counters provided measures of exposure. Airborne nanoparticles above background levels were detected by particle counters for all exposure scenarios. Nanoparticle number concentrations and particle size distributions were similar for sanding of treated versus untreated wood. Very few unbound nanoparticles were detected in aerosol samples via electron microscopy, rather nano-sized ZnO was contained within, or on the surface of larger airborne particles. Whether the presence of nanoscale ZnO in these aerosols affects toxicity merits further investigation. Mass-based exposure measurements were below the NIOSH Recommended Exposure Limit for Zn, although there are no established exposure limits for nanoscale ZnO. Local exhaust ventilation was effective, reducing airborne nanoparticle number concentrations by up to 92% and reducing personal exposure to total dust by at least 80% in terms of mass. Given the discrepancies between the particle count data and electron microscopy observations, the chemical identity of the airborne nanoparticles detected by the particle counters remains uncertain. Prior studies attributed the main source of nanoparticle emissions during sanding to copper nanoparticles generated from electric sander motors. Potentially contrary results are presented suggesting the sander motor may not have been

Characterization of silver nanoparticles in selected consumer products and its relevance for predicting children’s potential exposures

PubMed Central

Tulve, Nicolle S.; Stefaniak, Aleksandr B.; Vance, Marina E.; Rogers, Kim; Mwilu, Samuel; LeBouf, Ryan F.; Schwegler-Berry, Diane; Willis, Robert; Thomas, Treye A.; Marr, Linsey C.

2015-01-01

Due to their antifungal, antibacterial, antiviral, and antimicrobial properties, silver nanoparticles (AgNPs) are used in consumer products intended for use by children or in the home. Children may be especially affected by the normal use of consumer products because of their physiological functions, developmental stage, and activities and behaviors. Despite much research to date, children’s potential exposures to AgNPs are not well characterized. Our objectives were to characterize selected consumer products containing AgNPs and to use the data to estimate a child’s potential non-dietary ingestion exposure. We identified and cataloged 165 consumer products claiming to contain AgNPs that may be used by or near children or found in the home. Nineteen products (textile, liquid, plastic) were selected for further analysis. We developed a tiered analytical approach to determine silver content, form (particulate or ionic), size, morphology, agglomeration state, and composition. Silver was detected in all products except one sippy cup body. Among products in a given category, silver mass contributions were highly variable and not always uniformly distributed within products, highlighting the need to sample multiple areas of a product. Electron microscopy confirmed the presence of AgNPs. Using this data, a child’s potential non-dietary ingestion exposure to AgNPs when drinking milk formula from a sippy cup is 1.53 μg Ag/kg. Additional research is needed to understand the number and types of consumer products containing silver and the concentrations of silver in these products in order to more accurately predict children’s potential aggregate and cumulative exposures to AgNPs. PMID:25747543

Toddler exposure to flame retardant chemicals: Magnitude, health concern and potential risk- or protective factors of exposure: Observational studies summarized in a systematic review.

PubMed

Sugeng, Eva J; de Cock, Marijke; Schoonmade, Linda J; van de Bor, Margot

2017-10-01

Endocrine disrupting flame retardant (FR) chemicals form a human health concern, that is investigated mostly from the perspective of adult- and early life exposure. No overview of studies on toddler exposure and health effects exist. However, toddlerhood is a critical developmental period and toddlers are at increased risk for exposure because of their age-specific behavior. This systematic review encompasses toddler FR exposure studies in three countries, associated health effects and potential environmental, demographic, or behavioral risk- or protective factors for toddler exposure. A systematic literature search in four databases (PubMed, Embase.com, The Cochrane Library (via Wiley) and Web of Science Core collection) resulted in the identification of ten publications representing seven unique studies that measured brominated and/or phosphorylated FRs in toddlers' (8-24 month-old) serum, urine, hand wipes and feces. This review showed that toddlers are exposed to a range of FRs, that thyroid hormone disruption is associated with FR exposure and that factors in the indoor environment, including products such as plastic toys, might increase FR exposure. Considering the limited amount of studies, and the variety of biological matrices, FRs, and risk- and protective factors, this review did not reveal a uniform pattern of toddler exposure across the different cohorts studied. More evidence is necessary and considering the feasibility of invasive sampling in young children, we suggest to emphasize research on non-invasive matrices. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Equivalent magnetic vector potential model for low-frequency magnetic exposure assessment.

PubMed

Diao, Y L; Sun, W N; He, Y Q; Leung, S W; Siu, Y M

2017-09-21

In this paper, a novel source model based on a magnetic vector potential for the assessment of induced electric field strength in a human body exposed to the low-frequency (LF) magnetic field of an electrical appliance is presented. The construction of the vector potential model requires only a single-component magnetic field to be measured close to the appliance under test, hence relieving considerable practical measurement effort-the radial basis functions (RBFs) are adopted for the interpolation of discrete measurements; the magnetic vector potential model can then be directly constructed by summing a set of simple algebraic functions of RBF parameters. The vector potentials are then incorporated into numerical calculations as the equivalent source for evaluations of the induced electric field in the human body model. The accuracy and effectiveness of the proposed model are demonstrated by comparing the induced electric field in a human model to that of the full-wave simulation. This study presents a simple and effective approach for modelling the LF magnetic source. The result of this study could simplify the compliance test procedure for assessing an electrical appliance regarding LF magnetic exposure.

Equivalent magnetic vector potential model for low-frequency magnetic exposure assessment

NASA Astrophysics Data System (ADS)

Diao, Y. L.; Sun, W. N.; He, Y. Q.; Leung, S. W.; Siu, Y. M.

2017-10-01

In this paper, a novel source model based on a magnetic vector potential for the assessment of induced electric field strength in a human body exposed to the low-frequency (LF) magnetic field of an electrical appliance is presented. The construction of the vector potential model requires only a single-component magnetic field to be measured close to the appliance under test, hence relieving considerable practical measurement effort—the radial basis functions (RBFs) are adopted for the interpolation of discrete measurements; the magnetic vector potential model can then be directly constructed by summing a set of simple algebraic functions of RBF parameters. The vector potentials are then incorporated into numerical calculations as the equivalent source for evaluations of the induced electric field in the human body model. The accuracy and effectiveness of the proposed model are demonstrated by comparing the induced electric field in a human model to that of the full-wave simulation. This study presents a simple and effective approach for modelling the LF magnetic source. The result of this study could simplify the compliance test procedure for assessing an electrical appliance regarding LF magnetic exposure.

Oral Chromium Exposure and Toxicity

PubMed Central

Sun, Hong; Brocato, Jason

2015-01-01

Hexavalent chromium [Cr(VI)] is a known carcinogen when inhaled. However, inhalational exposure to Cr(VI) affects only a small portion of the population, mainly by occupational exposures. In contrast, oral exposure to Cr(VI) is widespread and affects many people throughout the globe. In 2008, the National Toxicology Program (NTP) released a 2-year study demonstrating that ingested Cr(VI) was carcinogenic in rats and mice. The effects of Cr(VI) oral exposure is mitigated by reduction in the gut, however a portion evades the reductive detoxification and reaches target tissues. Once Cr(VI) enters the cell, it ultimately gets reduced to Cr(III), which mediates its toxicity via induction of oxidative stress during the reduction while Cr intermediates react with protein and DNA. Cr(III) can form adducts with DNA that may lead to mutations. This review will discuss the potential adverse effects of oral exposure to Cr(VI) by presenting up-to-date human and animal studies, examining the underlying mechanisms that mediate Cr(VI) toxicity, as well as highlighting opportunities for future research. PMID:26231506

Parameter uncertainty and variability in evaluative fate and exposure models

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

Hertwich, E.G.; McKone, T.E.; Pease, W.S.

The human toxicity potential, a weighting scheme used to evaluate toxic emissions for life cycle assessment and toxics release inventories, is based on potential dose calculations and toxicity factors. This paper evaluates the variance in potential dose calculations that can be attributed to the uncertainty in chemical-specific input parameters as well as the variability in exposure factors and landscape parameters. A knowledge of the uncertainty allows us to assess the robustness of a decision based on the toxicity potential; a knowledge of the sources of uncertainty allows one to focus resources if the uncertainty is to be reduced. The potentialmore » does of 236 chemicals was assessed. The chemicals were grouped by dominant exposure route, and a Monte Carlo analysis was conducted for one representative chemical in each group. The variance is typically one to two orders of magnitude. For comparison, the point estimates in potential dose for 236 chemicals span ten orders of magnitude. Most of the variance in the potential dose is due to chemical-specific input parameters, especially half-lives, although exposure factors such as fish intake and the source of drinking water can be important for chemicals whose dominant exposure is through indirect routes. Landscape characteristics are generally of minor importance.« less

Estimated Daily Phthalate Exposures in a Population of Mothers of Male Infants Exhibiting Reduced Anogenital Distance

PubMed Central

Marsee, Kevin; Woodruff, Tracey J.; Axelrad, Daniel A.; Calafat, Antonia M.; Swan, Shanna H.

2006-01-01

Phthalate diesters have been shown to be developmental and reproductive toxicants in animal studies. A recent epidemiologic study showed certain phthalates to be significantly associated with reduced anogenital distance in human male infants, the first evidence of subtle developmental effects in human male infants exposed prenatally to phthalates. We used two previously published methods to estimate the daily phthalate exposures for the four phthalates whose urinary metabolites were statistically significantly associated with developmental effects in the 214 mother–infant pairs [di-n-butyl phthalate (DnBP), diethyl phthalate (DEP), butylbenzyl phthalate (BBzP), diisobutyl phthalate (DiBP)] and for another important phthalate [di-2-ethylhexyl phthalate (DEHP)]. We estimated the median and 95th percentile of daily exposures to DBP to be 0.99 and 2.68 μg/kg/day, respectively; for DEP, 6.64 and 112.3 μg/kg/day; for BBzP, 0.50 and 2.47 μg/kg/day; and for DEHP, 1.32 and 9.32 μg/kg/day. The U.S. Environmental Protection Agency (EPA) reference doses for these chemicals are 100 (DBP), 800 (DEP), 200 (BBzP), and 20 (DEHP) μg/kg/day. The median and 95th percentile exposure estimates for the phthalates associated with reduced anogenital distance in the study population are substantially lower than current U.S. EPA reference doses for these chemicals and could be informative to any updates of the hazard assessments and risk assessments for these chemicals. PMID:16759976

A randomized intervention trial to reduce mechanical exposures in the Colombian flower industry.

PubMed

Barrero, L H; Ceballos, C; Ellegast, R; Pulido, J A; Monroy, M; Berrio, S; Quintana, L A

2014-01-01

Evidence on effectiveness of ergonomic interventions to reduce mechanical demands of the upper extremity is scarce in agriculture. To conduct an ergonomic intervention to reduce mechanical exposures on workers during manual flower cutting, while emphasizing postural education and reduction of force requirements. Seventy seven workers (20 to 55 years old; 80% women) from six companies that cultivate roses participated in this study. Participants from three companies were randomly assigned to control and intervention groups. A postural education program and a maintenance program was designed and implemented in the intervention group aiming to achieve more neutral postures of the wrist and forearm and to reduce force requirements during rose cutting. Changes in self-reported effort and upper extremity postures, kinematics and muscular activity between baseline and follow-up assessments were evaluated. Most of the observed changes in the evaluated mechanical exposures were moderate for both groups. The intervention group showed differential improvements compared to the control group for 95th percentile forearm pronation (intervention group went from 50.6 to 35.6°; control group went from 18.4 to 34.7°); and to some degree for the maximum wrist radial deviation (the intervention group went from 17° to 7.6°; control group went from 10.1° to 7.8°). Also, the mean elbow flexion for the control group was reduced from 62.3 to 48.4°, whereas it increased from 52.2 to 57.3° in the intervention group. No differential changes between the intervention and control groups were observed for the kinematic variables, except for an unexpected reduction in the 95th percentile velocity of wrist flexion-extension in the control group, which was not observed in the intervention group. Lastly, although observed changes in muscular activity were not statistically significant, improvements were observed for the intervention group for the flexor and extensor carpi radialis and the

Wind-Driven Erosion and Exposure Potential at Mars 2020 Rover Candidate-Landing Sites.

PubMed

Chojnacki, Matthew; Banks, Maria; Urso, Anna

2018-02-01

Aeolian processes have likely been the predominant geomorphic agent for most of Mars' history and have the potential to produce relatively young exposure ages for geologic units. Thus, identifying local evidence for aeolian erosion is highly relevant to the selection of landing sites for future missions, such as the Mars 2020 Rover mission that aims to explore astrobiologically relevant ancient environments. Here we investigate wind-driven activity at eight Mars 2020 candidate-landing sites to constrain erosion potential at these locations. To demonstrate our methods, we found that contemporary dune-derived abrasion rates were in agreement with rover-derived exhumation rates at Gale crater and could be employed elsewhere. The Holden crater candidate site was interpreted to have low contemporary erosion rates, based on the presence of a thick sand coverage of static ripples. Active ripples at the Eberswalde and southwest Melas sites may account for local erosion and the dearth of small craters. Moderate-flux regional dunes near Mawrth Vallis were deemed unrepresentative of the candidate site, which is interpreted to currently be experiencing low levels of erosion. The Nili Fossae site displayed the most unambiguous evidence for local sand transport and erosion, likely yielding relatively young exposure ages. The downselected Jezero crater and northeast Syrtis sites had high-flux neighboring dunes and exhibited substantial evidence for sediment pathways across their ellipses. Both sites had relatively high estimated abrasion rates, which would yield young exposure ages. The downselected Columbia Hills site lacked evidence for sand movement, and contemporary local erosion rates are estimated to be relatively low.

Wind-Driven Erosion and Exposure Potential at Mars 2020 Rover Candidate-Landing Sites

PubMed Central

Chojnacki, Matthew; Banks, Maria; Urso, Anna

2018-01-01

Aeolian processes have likely been the predominant geomorphic agent for most of Mars’ history and have the potential to produce relatively young exposure ages for geologic units. Thus, identifying local evidence for aeolian erosion is highly relevant to the selection of landing sites for future missions, such as the Mars 2020 Rover mission that aims to explore astrobiologically relevant ancient environments. Here we investigate wind-driven activity at eight Mars 2020 candidate-landing sites to constrain erosion potential at these locations. To demonstrate our methods, we found that contemporary dune-derived abrasion rates were in agreement with rover-derived exhumation rates at Gale crater and could be employed elsewhere. The Holden crater candidate site was interpreted to have low contemporary erosion rates, based on the presence of a thick sand coverage of static ripples. Active ripples at the Eberswalde and southwest Melas sites may account for local erosion and the dearth of small craters. Moderate-flux regional dunes near Mawrth Vallis were deemed unrepresentative of the candidate site, which is interpreted to currently be experiencing low levels of erosion. The Nili Fossae site displayed the most unambiguous evidence for local sand transport and erosion, likely yielding relatively young exposure ages. The downselected Jezero crater and northeast Syrtis sites had high-flux neighboring dunes and exhibited substantial evidence for sediment pathways across their ellipses. Both sites had relatively high estimated abrasion rates, which would yield young exposure ages. The downselected Columbia Hills site lacked evidence for sand movement, and contemporary local erosion rates are estimated to be relatively low. PMID:29568719

Wind-Driven Erosion and Exposure Potential at Mars 2020 Rover Candidate-Landing Sites

NASA Astrophysics Data System (ADS)

Chojnacki, Matthew; Banks, Maria; Urso, Anna

2018-02-01

Aeolian processes have likely been the predominant geomorphic agent for most of Mars' history and have the potential to produce relatively young exposure ages for geologic units. Thus, identifying local evidence for aeolian erosion is highly relevant to the selection of landing sites for future missions, such as the Mars 2020 Rover mission that aims to explore astrobiologically relevant ancient environments. Here we investigate wind-driven activity at eight Mars 2020 candidate-landing sites to constrain erosion potential at these locations. To demonstrate our methods, we found that contemporary dune-derived abrasion rates were in agreement with rover-derived exhumation rates at Gale crater and could be employed elsewhere. The Holden crater candidate site was interpreted to have low contemporary erosion rates, based on the presence of a thick sand coverage of static ripples. Active ripples at the Eberswalde and southwest Melas sites may account for local erosion and the dearth of small craters. Moderate-flux regional dunes near Mawrth Vallis were deemed unrepresentative of the candidate site, which is interpreted to currently be experiencing low levels of erosion. The Nili Fossae site displayed the most unambiguous evidence for local sand transport and erosion, likely yielding relatively young exposure ages. The downselected Jezero crater and northeast Syrtis sites had high-flux neighboring dunes and exhibited substantial evidence for sediment pathways across their ellipses. Both sites had relatively high estimated abrasion rates, which would yield young exposure ages. The downselected Columbia Hills site lacked evidence for sand movement, and contemporary local erosion rates are estimated to be relatively low.

Embryo-larval exposure to atrazine reduces viability and alters oxidative stress parameters in Drosophila melanogaster.

PubMed

Figueira, Fernanda Hernandes; Aguiar, Lais Mattos de; Rosa, Carlos Eduardo da

2017-01-01

The herbicide atrazine has been used worldwide with subsequent residual contamination of water and food, which may cause adverse effects on non-target organisms. Animal exposure to this herbicide may affect development, reproduction and energy metabolism. Here, the effects of atrazine regarding survival and redox metabolism were assessed in the fruit fly D. melanogaster exposed during embryonic and larval development. The embryos (newly fertilized eggs) were exposed to different atrazine concentrations (10μM and 100μM) in the diet until the adult fly emerged. Pupation and emergence rates, developmental time and sex ratio were determined as well as oxidative stress parameters and gene expression of the antioxidant defence system were evaluated in newly emerged male and female flies. Atrazine exposure reduced pupation and emergence rates in fruit flies without alterations to developmental time and sex ratio. Different redox imbalance patterns were observed between males and females exposed to atrazine. Atrazine caused an increase in oxidative damage, reactive oxygen species generation and antioxidant capacity and decreased thiol-containing molecules. Further, atrazine exposure altered the mRNA expression of antioxidant genes (keap1, sod, sod2, cat, irc, gss, gclm, gclc, trxt, trxr-1 and trxr-2). Reductions in fruit fly larval and pupal viability observed here are likely consequences of the oxidative stress induced by atrazine exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

Stevia rebaudiana Bertoni effect on the hemolytic potential of Listeria monocytogenes.

PubMed

Sansano, S; Rivas, A; Pina-Pérez, M C; Martinez, A; Rodrigo, D

2017-06-05

The effect of Stevia rebaudiana Bertoni on the hemolytic potential of Listeria monocytogenes was studied by means of the assessment of the Listeriolysin O (LLO) production. The three factors under study, stevia concentration in the range [0-2.5] % (w/v), incubation temperature (10 and 37°C), and exposure time (0-65h) significantly affected (p≤0.05) the hemolytic activity of L. monocytogenes. Results showed that at the lower incubation temperature the hemolytic potential of the bacterium was significantly reduced, from 100% at 37°C to 8% at 10°C (after 65h of incubation) in unsupplemented substrate (0% stevia). Irrespective of the temperature, 10 or 37°C, supplementation of the medium with stevia at 2.5 % (w/v) reduced the bacterium's hemolytic activity by a maximum of 100%. Furthermore, the time of exposure to 2.5 % (w/v) stevia concentration was also a significant factor reducing the hemolytic capability of L. monocytogenes. The possibility of reducing the pathogenic potential of L. monocytogenes (hemolysis) by exposure to stevia should be confirmed in real food matrices, opening a research niche with a valuable future impact on food safety. Copyright © 2017 Elsevier B.V. All rights reserved.

Mental Health Nurse’s Exposure to Workplace Violence Leads to Job Stress, Which Leads to Reduced Professional Quality of Life

PubMed Central

Itzhaki, Michal; Bluvstein, Irit; Peles Bortz, Anat; Kostistky, Hava; Bar Noy, Dor; Filshtinsky, Vivian; Theilla, Miriam

2018-01-01

Professional quality of life (ProQOL) reflects how individuals feel about their work as helpers. Psychiatric ward nurses cope with significant psychological and physical challenges, including exposure to verbal and physical violence. This study was based on two aspects of ProQOL, the positive compassion satisfaction, and the negative compassion fatigue, with the aim of investigating the relation of ProQOL to job stress and violence exposure at a large mental health center. Data were collected from 114 mental health nurses (49/63 M/F) who completed a self-administered questionnaire examining violence exposure, ProQOL, and job stress. The results showed that during the last year, almost all nurses (88.6%) experienced verbal violence, and more than half (56.1%) experienced physical violence. Only 2.6% experienced no violence. ProQOL was not associated with violence exposure but was reduced by work stress and by previous exposure to violence; nurses who perceived their work as more stressful had lower satisfaction from their work. In conclusion, although most mental health nurses are exposed to physical and verbal violence, their ProQOL is more related to job stress than to workplace violence (WPV). Hospital managements should conduct work stress reduction intervention programs and promote strategizes to reduce WPV. Further exploration of (a) factors affecting ProQOL and (b) the effect of violence coping workshops on ProQOL is warranted. PMID:29535652

Lead exposure potentiates predatory attack behavior in the cat.

PubMed

Li, Wenjie; Han, Shenggao; Gregg, Thomas R; Kemp, Francis W; Davidow, Amy L; Louria, Donald B; Siegel, Allan; Bogden, John D

2003-07-01

Epidemiologic studies have demonstrated that environmental lead exposure is associated with aggressive behavior in children; however, numerous confounding variables limit the ability of these studies to establish a causal relationship. The study of aggressive behavior using a validated animal model was used to test the hypothesis that there is a causal relationship between lead exposure and aggression in the absence of confounding variables. We studied the effects of lead exposure on a feline model of aggression: predatory (quiet biting) attack of an anesthetized rat. Five cats were stimulated with a precisely controlled electrical current via electrodes inserted into the lateral hypothalamus. The response measure was the predatory attack threshold current (i.e., the current required to elicit an attack response on 50% of the trials). Blocks of trials were administered in which predatory attack threshold currents were measured three times a week for a total of 6-10 weeks, including before, during, and after lead exposure. Lead was incorporated into cat food "treats" at doses of 50-150 mg/kg/day. Two of the five cats received a second period of lead exposure. Blood lead concentrations were measured twice a week and were <1, 21-77, and <20 micro g/dL prior to, during, and after lead exposure, respectively. The predatory attack threshold decreased significantly during initial lead exposure in three of five cats and increased after the cessation of lead exposure in four of the five cats (P<0.01). The predatory attack thresholds and blood lead concentrations for each cat were inversely correlated (r=-0.35 to -0.74). A random-effects mixed model demonstrated a significant (P=0.0019) negative association between threshold current and blood lead concentration. The data of this study demonstrate that lead exposure enhances predatory aggression in the cat and provide experimental support for a causal relationship between lead exposure and aggressive behavior in humans.

Analysis of PFAAs in American alligators part 2: Potential dietary exposure of South Carolina hunters from recreationally harvested alligator meat.

PubMed

Tipton, Jessica J; Guillette, Louis J; Lovelace, Susan; Parrott, Benjamin B; Rainwater, Thomas R; Reiner, Jessica L

2017-11-01

Exposure to perfluorinated alkyl acids (PFAAs) has been linked to many harmful health effects including reproductive disorders, developmental delays, and altered liver and kidney function. Most human exposure to environmental contaminants, including PFAAs, occurs through consumption of contaminated food or drinking water. This study uses PFAA data from meat samples collected from recreationally harvested American alligators (Alligator mississippiensis) in South Carolina to assess potential dietary exposure of hunters and their families to PFAAs. Consumption patterns were investigated using intercept surveys of 23 hunters at a wild game meat processor. An exposure scenario using the average consumption frequency, portion size, and median perfluorooctane sulfonic acid (PFOS) concentration in alligator meat from all hunt units found the daily dietary exposure to be 2.11ng/kg body weight per day for an adult human. Dietary PFOS exposure scenarios based on location of harvest suggested the highest daily exposure occurs with alligator meat from the Middle Coastal hunt unit in South Carolina. Although no samples were found to exceed the recommended threshold for no consumption of PFOS found in Minnesota state guidelines, exposure to a mixture of PFAAs found in alligator meat and site-specific exposures based on harvest location should be considered in determining an appropriate guideline for vulnerable populations potentially exposed to PFAAs through consumption of wild alligator meat. Copyright © 2017. Published by Elsevier B.V.

Air pollution, weight loss and metabolic benefits of bariatric surgery: a potential model for study of metabolic effects of environmental exposures.

PubMed

Ghosh, R; Gauderman, W J; Minor, H; Youn, H A; Lurmann, F; Cromar, K R; Chatzi, L; Belcher, B; Fielding, C R; McConnell, R

2018-05-01

Emerging experimental evidence suggests that air pollution may contribute to development of obesity and diabetes, but studies of children are limited. We hypothesized that pollution effects would be magnified after bariatric surgery for treatment of obesity, reducing benefits of surgery. In 75 obese adolescents, excess weight loss (EWL), high-density lipoprotein (HDL) cholesterol, triglycerides, alkaline phosphatase (ALP) and hemoglobin A1c (HbA 1c ) were measured prospectively at baseline and following laparoscopic adjustable gastric banding (LAGB). Residential distances to major roads and the average two-year follow-up exposure to particulate matter <2.5 μm (PM 2.5 ), nitrogen dioxide (NO 2 ) and ozone were estimated. Associations of exposure with change in outcome and with attained outcome two years post-surgery were examined. Major-roadway proximity was associated with reduced EWL and less improvement in lipid profile and ALP after surgery. NO 2 was associated with less improvement in HbA 1c and lower attained HDL levels and change in triglycerides over two years post-surgery. PM 2.5 was associated with reduced EWL and reduced beneficial change or attained levels for all outcomes except HbA 1c . Near-roadway, PM 2.5 and NO 2 exposures at levels common in developed countries were associated with reduced EWL and metabolic benefits of LAGB. This novel approach provides a model for investigating metabolic effects of other exposures. © 2017 World Obesity Federation.

Cadmium in arctic Alaska wildlife: Kidney and liver residues and potential exposure in indigenous people

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

O`Hara, T.; Fairbrother, A.; Becker, P.

1995-12-31

In arctic Alaska, cadmium (Cd) levels are of concern in kidney and liver of terrestrial and marine mammals including: bowhead whale, beluga whale, walrus, caribou, and ringed seal. Cd levels in some animals exceed threshold criteria in kidney for renal dysfunction and other effects, tolerance levels for human consumption (liver = 1 ppm, kidney = 3 ppm), and WHO weekly intake limits (500 ug Cd/week). An assessment of risk to indigenous people and to wildlife populations, will be presented. Cigarette smoking is another major source of Cd to be considered. Reports from Greenland have concluded a health risk from Cdmore » exposure from marine dietary sources and smoking exist for these residents. Bowhead whale kidney and walrus kidney and liver represent major dietary sources of Cd (blubber and meat have very little Cd). Followed by: ringed seal liver (kidney data not available), beluga whale liver and kidney, and caribou kidney. Small portions of bowhead and walrus kidney (< 10g/week) exceed weekly intake levels. Age positively correlates with Cd levels in kidney indicating that avoiding older (larger) animals would reduce exposure. Adverse effects of Cd in wildlife were not grossly evident, however, with no historic data, it is difficult to determine if tissue concentrations are elevated. Harvest of wildlife is important to many arctic people for nutritional and cultural survival. Assessing risks associated with contaminants is essential for the wellbeing of indigenous people and wildlife. The nutritional value of the local resources and the potential inadequate alternatives must be considered.« less

Electromagnetic navigation reduces surgical time and radiation exposure for proximal interlocking in retrograde femoral nailing.

PubMed

Somerson, Jeremy S; Rowley, David; Kennedy, Chad; Buttacavoli, Frank; Agarwal, Animesh

2014-07-01

To compare the time required for proximal locking screw placement between a standard freehand technique and the navigated technique, and to quantify the reduction in ionizing radiation exposure. A fresh frozen cadaver model was used for 48 proximal interlocking screw procedures. Each procedure consisted of insertion of 2 anteroposterior locking screws. Standard fluoroscopic technique was used for 24 procedures, and an electromagnetic navigation system was used for the remaining 24 procedures. Procedure duration was recorded using an electronic timer and radiation doses were documented. Mean total insertion time for both proximal interlocking screws was 405 ± 165.7 seconds with the freehand technique and 311 ± 78.3 seconds in the navigation group (P = 0.002). All procedures resulted in successful locking screw placement. Mean ionizing radiation exposure time for proximal locking was 29.5 ± 12.8 seconds. Proximal locking screw insertion using the navigation technique evaluated in this work was significantly faster than the standard fluoroscopic method. The navigated technique is effective and has the potential to prevent ionizing radiation exposure.

Pyrethroids in indoor air during application of various mosquito repellents: Occurrence, dissipation and potential exposure risk.

PubMed

Li, Huizhen; Lydy, Michael J; You, Jing

2016-02-01

Commercial mosquito repellents (MRs) are generally applied as mosquito coils, electric vaporizers (liquid and solid) or aerosol spray, with pyrethroids often being the active ingredients. Four types of MRs were applied individually in a 13-m(2) bedroom to study the occurrence, dissipation and risk of pyrethroids in indoor environments. Total air concentrations (in gas and particle phases) of allethrin, cypermethrin, dimefluthrin and tetramethrin during MR applications were three to six orders of magnitude higher than indoor levels before the applications, and allethrin emitted from a vaporizing mat reached the highest concentration measured during the current study (18,600 ± 4980 ng m(-3)). The fate of airborne pyrethroids was different when the four MRs were applied. Particle-associated allethrin accounted for 95% of its total concentration from the aerosol spray, and was significantly higher than the vaporizing mat (67%), suggesting that the released phase of MRs and size distribution of pyrethroid-carrying particles played important roles in the gas-particle partitioning process. In addition, air exchange through open windows more effectively reduced the levels of indoor pyrethroids than ventilation using an air conditioner. The inhalation risk quotients (RQ) for allethrin derived from application of the vaporizing mat ranged from 1.04 ± 0.40 to 1.98 ± 0.75 for different age-subgroups of the population, suggesting potential exposure risk. Special attention should be given concerning indoor exposure of pyrethroids to these vulnerable groups. Copyright © 2015 Elsevier Ltd. All rights reserved.

National estimates of exposure to prescription drugs with addiction potential in community-dwelling elders.

PubMed

Simoni-Wastila, Linda; Zuckerman, Ilene H; Singhal, Puneet K; Briesacher, Becky; Hsu, Van Doren

2005-03-01

The use of prescription drugs with addiction potential is an overlooked and growing problem among today's elderly. This paper provides national prevalence estimates of exposure to prescription drugs with addiction potential among community-dwelling elders and explores risk factors for such exposure. Using the Medicare Current Beneficiary Survey, a nationally-representative database of Medicare eligibles, we calculated the prevalence of abusable prescription drug use, overall, by therapeutic class, and by drug. Nearly 22% (7.22 million) of all community-dwelling Medicare elders used at least one prescription medication with addiction potential. Opioid analgesics were used most frequently (14.9%; 95% CI 14.0, 15.8%); central nervous system (CNS) depressants were used by 10.4% of the nation's elders (95% CI 9.5, 10.8%). Using logistic regression analysis, we examined the association of explanatory variables with three outcome variables: any controlled substances use, any opioid analgesic use, and any CNS depressant use. We found that females, whites, those aged 65-79, and those with non-spousal others, were significantly more likely to use one or more prescription drugs with addiction potential, controlling for health status and severity-of-illness. The significance and magnitude of several explanatory variables, including age, race, ethnicity, living arrangement, and health status, varied by therapeutic category. This paper provides an important first step in acknowledging the widespread use of abusable prescription drugs in elders, and provides a foundation for future research and practical solutions to preventing subsequent problem use of prescription drugs.

Effect of sorption on exposures to organic gases from environmental tobacco smoke (ETS)

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

Singer, B.C.; Hodgson, A.T.; Nazaroff, W.W.

The effects of sorption processes on dynamic ETS organic gas concentrations and potential exposures were studied in a carpeted and furnished 50-m{sup 3} room ventilated at 0.6 h{sup -1}. Ten cigarettes were machine-smoked on six of every seven days over four weeks. Concentrations of ETS-specific tracers and regulated toxic compounds were quantified during daily smoking, post-smoking and background periods. Potential exposures were calculated by period and day. Large sorption effects were observed for the widely used tracers 3-ethenylpyridine and nicotine, and for several toxic compounds including naphthalene and cresol isomers. Short-term adsorption to indoor surfaces reduced concentrations and potential exposuresmore » during smoking, while later reemission increased concentrations and exposures hours after smoking ended. Concentrations during nonsmoking periods rose from day to day over the first few weeks, presumably from increased reemission associated with increased sorbed mass concentrations. For sorbing compounds, more than half of daily potential exposures occurred during nonsmoking periods.« less

CARDIOVASCULAR INJURY FROM ACUTE AND REPEATED EXPOSURE TO PARTICULATE MATTER (PM): POTENTIAL ROLE OF ZINC

EPA Science Inventory

CARDIOVASCULAR INJURY FROM ACUTE AND REPEATED EXPOSURE TO PARTICULATE MATTER (PM): POTENTIAL ROLE OF ZINC. UP Kodavanti, MC Schladweiler, AD Ledbetter, RH Jaskot, PS Gilmour, DC Christiani, WP Watkinson, DL Costa, JK McGee, A Nyska. NHEERL, USEPA, RTP, NC; CEMALB, UNC, Chapel Hil...

Safe Use of Acoustic Vestibular-Evoked Myogenic Potential Stimuli: Protocol and Patient-Specific Considerations.

PubMed

Portnuff, Cory D F; Kleindienst, Samantha; Bogle, Jamie M

2017-09-01

Vestibular-evoked myogenic potentials (VEMPs) are commonly used clinical assessments for patients with complaints of dizziness. However, relatively high air-conducted stimuli are required to elicit the VEMP, and ultimately may compromise safe noise exposure limits. Recently, research has reported the potential for noise-induced hearing loss (NIHL) from VEMP stimulus exposure through studies of reduced otoacoustic emission levels after VEMP testing, as well as a recent case study showing permanent sensorineural hearing loss associated with VEMP exposure. The purpose of this report is to review the potential for hazardous noise exposure from VEMP stimuli and to suggest clinical parameters for safe VEMP testing. Literature review with presentation of clinical guidelines and a clinical tool for estimating noise exposure. The literature surrounding VEMP stimulus-induced hearing loss is reviewed, including several cases of overexposure. The article then presents a clinical calculation tool for the estimation of a patient's safe noise exposure from VEMP stimuli, considering stimulus parameters, and includes a discussion of how varying stimulus parameters affect a patient's noise exposure. Finally, recommendations are provided for recognizing and managing specific patient populations who may be at higher risk for NIHL from VEMP stimulus exposure. A sample protocol is provided that allows for safe noise exposure. VEMP stimuli have the potential to cause NIHL due to high sound exposure levels. However, with proper safety protocols in place, clinicians may reduce or eliminate this risk to their patients. Use of the tools provided, including the noise exposure calculation tool and sample protocols, may help clinicians to understand and ensure safe use of VEMP stimuli. American Academy of Audiology

Exposure to aged crumb rubber reduces survival time during a stress test in earthworms (Eisenia fetida).

PubMed

Pochron, Sharon; Nikakis, Jacqueline; Illuzzi, Kyra; Baatz, Andrea; Demirciyan, Loriana; Dhillon, Amritjot; Gaylor, Thomas; Manganaro, Alexa; Maritato, Nicholas; Moawad, Michael; Singh, Rajwinder; Tucker, Clara; Vaughan, Daniel

2018-04-01

Solid waste management struggles with the sustainable disposal of used tires. One solution involves shredding used tires into crumb rubber and using the material as infill for artificial turf. However, crumb rubber contains hydrocarbons, organic compounds, and heavy metals, and it travels into the environment. Earthworms living in soil contaminated with virgin crumb rubber gained 14% less body weight than did earthworms living in uncontaminated soil, but the impact of aged crumb rubber on the earthworms is unknown. Since many athletic fields contain aged crumb rubber, we compared the body weight, survivorship, and longevity in heat and light stress for earthworms living in clean topsoil to those living in topsoil contaminated with aged crumb rubber. We also characterized levels of metals, nutrients, and micronutrients of both soil treatments and compared those to published values for soil contaminated with virgin crumb rubber. Consistent with earlier research, we found that contaminated soil did not inhibit microbial respiration rates. Aged crumb rubber, like new crumb rubber, had high levels of zinc. However, while exposure to aged crumb rubber did not reduce earthworm body weight as did exposure to new crumb rubber, exposure to aged crumb rubber reduced earthworm survival time during a stress test by a statistically significant 38 min (16.2%) relative to the survival time for worms that had lived in clean soil. Aged crumb rubber and new crumb rubber appear to pose similar toxic risks to earthworms. This study suggests an environmental cost associated with the current tire-recycling solution.

Malaria transmission potential could be reduced with current and future climate change.

PubMed

Murdock, C C; Sternberg, E D; Thomas, M B

2016-06-21

Several studies suggest the potential for climate change to increase malaria incidence in cooler, marginal transmission environments. However, the effect of increasing temperature in warmer regions where conditions currently support endemic transmission has received less attention. We investigate how increases in temperature from optimal conditions (27 °C to 30 °C and 33 °C) interact with realistic diurnal temperature ranges (DTR: ± 0 °C, 3 °C, and 4.5 °C) to affect the ability of key vector species from Africa and Asia (Anopheles gambiae and An. stephensi) to transmit the human malaria parasite, Plasmodium falciparum. The effects of increasing temperature and DTR on parasite prevalence, parasite intensity, and mosquito mortality decreased overall vectorial capacity for both mosquito species. Increases of 3 °C from 27 °C reduced vectorial capacity by 51-89% depending on species and DTR, with increases in DTR alone potentially halving transmission. At 33 °C, transmission potential was further reduced for An. stephensi and blocked completely in An. gambiae. These results suggest that small shifts in temperature could play a substantial role in malaria transmission dynamics, yet few empirical or modeling studies consider such effects. They further suggest that rather than increase risk, current and future warming could reduce transmission potential in existing high transmission settings.

Potentiation of pulmonary reflex response to capsaicin 24h following whole-body acrolein exposure is mediated by TRPV1.

PubMed

Hazari, Mehdi S; Rowan, William H; Winsett, Darrell W; Ledbetter, Allen D; Haykal-Coates, Najwa; Watkinson, William P; Costa, Daniel L

2008-02-01

Pulmonary C-fibers are stimulated by irritant air pollutants producing apnea, bronchospasm, and decrease in HR. Chemoreflex responses resulting from C-fiber activation are sometimes mediated by TRPV1 and release of substance P. While acrolein has been shown to stimulate C-fibers, the persistence of acrolein effects and the role of C-fibers in these responses are unknown. These experiments were designed to determine the effects of whole-body acrolein exposure and pulmonary chemoreflex response post-acrolein. Rats were exposed to either air or 3 ppm acrolein for 3 h while ventilatory function and HR were measured; 1-day later response to capsaicin challenge was measured in anesthetized rats. Rats experienced apnea and decrease in HR upon exposure to acrolein, which was not affected by either TRPV1 antagonist or NK(1)R antagonist pretreatment. Twenty-four hours later, capsaicin caused apnea and bronchoconstriction in control rats, which was potentiated in rats exposed to acrolein. Pretreatment with TRPV1 antagonist or NK(1)R antagonist prevented potentiation of apneic response and bronchoconstriction 24h post-exposure. These data suggest that although potentiation of pulmonary chemoreflex response 24h post-acrolein is mediated by TRPV1 and release of substance P, cardiopulmonary inhibition during whole-body acrolein exposure is mediated through other mechanisms.

Identifying potential exposure reduction priorities using regional rankings based on emissions of known and suspected carcinogens to outdoor air in Canada.

PubMed

Setton, Eleanor M; Veerman, Basil; Erickson, Anders; Deschenes, Steeve; Cheasley, Roz; Poplawski, Karla; Demers, Paul A; Keller, C Peter

2015-08-22

important limitations similar to other emissions inventory-based tools. Additional research is required to evaluate how the Emissions Mapping Project is used by different groups and organizations with respect to informing actions aimed at reducing Canadians' potential exposure to harmful air pollutants.