Studies Of Environmental Exposures Research Articles

Delineating Urbanicity and Rurality: Impact on Environmental Exposure Assessment.

Environmental exposures and their health impacts can vary substantially between urban and rural areas. However, different methods for classifying these areas could lead to inconsistencies in environmental exposure and health studies, which are often overlooked. We constructed different urban/rural classification systems based on multiple population-based (e.g., total population, population density, and commuting) and built-environment-based (e.g., nighttime light intensity, building density, road density, distance to urban centers, point of interest density, and urban area coverage) indicators and various classification schemes. These classification systems were applied to Virginia and West Virginia, United States. We compared differences in urban/rural spatial patterns, demographic compositions, and exposures of particulate matter (PM2.5), greenspace, and land surface temperature using these urban/rural classification systems to understand their impacts on environmental exposure and health research. Our findings reveal clear differences in spatial patterns and demographic compositions across various systems. We also observed that different systems can lead to changes in the magnitude and direction of urban/rural disparities in environmental exposure assessment. Addressing the complexities in delineating urbanicity and rurality may include careful consideration of classification systems to reflect those aspects of urbanicity and rurality that are relevant to the research question or the use of multiple, complementary systems.

The Study of Environmental Exposure of Mothers and Infants Impacted by Large-Scale Agriculture (SEMILLA): Description of the Aims and Methods of a Community-Based Birth Cohort Study.

Women of childbearing age not only reside in agricultural communities but also form an integral part of the agricultural labor force. Limited research investigates the impact of prenatal fungicide exposure on infant health, specifically ethylenebisdithiocarbamates and their toxic by-product, ethylenethiourea (ETU), particularly in occupational settings. This paper describes the background, aims, protocol, and baseline sample characteristics for the SEMILLA study, which investigates prenatal ETU exposure, neonatal thyroid function, infant growth, and neurobehavioral development in an agricultural region of Ecuador. This cohort study follows pregnant women and their infants up to 18 months of age, incorporating urinary biomarkers and survey data on ETU exposure and infant growth and neurodevelopmental measures. Data collection includes detailed questionnaires, scales, and physical examinations on maternal and infant health and development, as well as environmental factors. Descriptive statistics on key characteristics of the study population at baseline are presented. SEMILLA enrolled 409 participants (72% enrollment rate): 111 agricultural workers (mostly floricultural), 149 non-agricultural workers, and 149 non-workers. Baseline characteristics show comparability between work sector groups, with some economic differences. SEMILLA will provide key evidence on prenatal fungicide exposure and infant development and encompass comprehensive multistage data collection procedures in pregnancy and infancy, focusing on structural and social determinants of health as well as individual-level chemical exposures. The community-based approach has proven essential, even amid challenges like the COVID-19 pandemic. The medium-term objective is to inform sustainable interventions promoting maternal and child health, with a long-term goal to reduce community exposures and improve worker health policies, particularly for women and pregnant workers.

Documenting Compliance and Symptom Reactivity for Ambulatory Assessment Methodology Following Concussion in Adolescents and Young Adults: Feasibility of the Mobile Neurocognitive Health (MNCH) Project.

Evaluate compliance, symptom reactivity, and acceptability/experience ratings for an ecological momentary assessment (EMA) protocol involving ultra-brief ambulatory cognitive assessments in adolescent and young adult patients with concussion. Outpatient concussion clinic. 116 patients aged 13 to 25years with concussion. Prospective research design was used to examine compliance, symptom reactivity, and acceptability/experience for the Mobile Neurocognitive Health Project (MNCH); an EMA study of environmental exposures, symptoms, objective cognitive functioning, and symptom reactivity involving 4, daily EMA surveys (7:30 am, 10:30 am, 3:00 pm, 8:00 pm) for a period of 7 days following concussion. Overall compliance rates, symptom reactivity scores, and participant acceptability/experience ratings were described. A series of non-parametric Friedman Tests with post-hoc Wilcoxon signed-rank tests were used to examine differences in compliance and reactivity related to time of day and over the course of the protocol (first 3 days [Early Week] vs last 4 days [Late Week]). Compliance rates, symptom reactivity scores, participant experience/acceptability. Overall median compliance was 71%, and there were significantly fewer 7:30 am surveys completed compared to the 10:30 am (Z =-4.88,P ≤.001), 3:00 pm (Z =-4.13,P ≤.001), and 8:00 pm (Z =-4.68, P ≤.001) surveys. Compliance for Early Week surveys were significantly higher than Late Week (Z =-2.16,P =.009). The median symptom reactivity score was 34.39 out of 100 and was significantly higher for Early Week compared to Late Week (Z =-4.59,P ≤.001). Ninety-nine percent (89/90) of the sample agreed that the app was easy to use, and 18% (16/90) indicated that the app interfered with their daily life. Adolescents and young adults with concussion were compliant with the MNCH EMA protocol. Symptom reactivity to the protocol was low and the majority of participants reported that the app and protocol were acceptable. These findings support further investigation into applications of EMA for use in concussion studies.

Impact of Wildfires on Cardiovascular Health.

Wildfire smoke (WFS) is a mixture of respirable particulate matter, environmental gases, and other hazardous pollutants that originate from the unplanned burning of arid vegetation during wildfires. The increasing size and frequency of recent wildfires has escalated public and occupational health concerns regarding WFS inhalation, by either individuals living nearby and downstream an active fire or wildland firefighters and other workers that face unavoidable exposure because of their profession. In this review, we first synthesize current evidence from environmental, controlled, and interventional human exposure studies, to highlight positive associations between WFS inhalation and cardiovascular morbidity and mortality. Motivated by these findings, we discuss preventative measures and suggest interventions to mitigate the cardiovascular impact of wildfires. We then review animal and cell exposure studies to call attention on the pathophysiological processes that support the deterioration of cardiovascular tissues and organs in response to WFS inhalation. Acknowledging the challenges of integrating evidence across independent sources, we contextualize laboratory-scale exposure approaches according to the biological processes that they model and offer suggestions for ensuring relevance to the human condition. Noting that wildfires are significant contributors to ambient air pollution, we compare the biological responses triggered by WFS to those of other harmful pollutants. We also review evidence for how WFS inhalation may trigger mechanisms that have been proposed as mediators of adverse cardiovascular effects upon exposure to air pollution. We finally conclude by highlighting research areas that demand further consideration. Overall, we aspire for this work to serve as a catalyst for regulatory initiatives to mitigate the adverse cardiovascular effects of WFS inhalation in the community and alleviate the occupational risk in wildland firefighters.

The Comet Assay as a Tool in Human Biomonitoring Studies of Environmental and Occupational Exposure to Chemicals-A Systematic Scoping Review.

Biomonitoring of human populations exposed to chemical substances that can act as potential mutagens or carcinogens, may enable the detection of damage and early disease prevention. In recent years, the comet assay has become an important tool for assessing DNA damage, both in environmental and occupational exposure contexts. To evidence the role of the comet assay in human biomonitoring, we have analysed original research studies of environmental or occupational exposure that used the comet assay in their assessments, following the PRISMA-ScR method (preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews). Groups of chemicals were designated according to a broad classification, and the results obtained from over 300 original studies (n = 123 on air pollutants, n = 14 on anaesthetics, n = 18 on antineoplastic drugs, n = 57 on heavy metals, n = 59 on pesticides, and n = 49 on solvents) showed overall higher values of DNA strand breaks in the exposed subjects in comparison with the unexposed. In summary, our systematic scoping review strengthens the relevance of the use of the comet assay in assessing DNA damage in human biomonitoring studies.

Population-based study of environmental heavy metal exposure and hearing loss: A systematic review and meta-analysis.

Previous studies have shown an association between environmental exposure to heavy metals and hearing loss. However, the findings regarding the relationship between exposure to different metals and hearing loss development are inconsistent. To address this, we conducted a meta-analysis to explore the link between common heavy metal exposures and hearing loss. This study examined the effects of lead (Pb), cadmium (Cd), and mercury (Hg) pollution on hearing loss at various levels, and systematically reviewed the literature on manganese (Mn), barium (Ba), arsenic (As), and hearing loss. We conducted systematic searches in five major databases, including PubMed, Web of Science, Embase, Cochrane Library, and Scopus. In addition, we searched three Chinese digital libraries: CNKI, Wanfang Data, and Wipu. From an initial pool of 649 articles, we carefully screened and selected 15 articles for further analysis. The effect sizes from these selected studies were synthesized through a meta-analysis to calculate the overall effect size. Our findings showed that: (1) There was a significant association between Pb and Cd exposure and hearing loss; (2) There is a proportional relationship between the increase of metal index detected in blood and hearing loss; (3) In the PTA measurement of hearing loss at different frequencies, the 4 kHz high frequency range had a stronger correlation with hearing loss than the low frequency, with OR 1.44 (1.22, 1.71); and (4) There was a more significant correlation between Barium (Ba) levels in nails and hair than in urine. The study presented evidence of a significant association between human hearing loss and exposure to lead (Pb) and cadmium (Cd). It not only revealed a positive correlation between blood heavy metal concentrations and the incidence of hearing loss but also highlighted that long-term exposure indicators of heavy metals were more indicative of the correlation with hearing loss. Lastly, the study recommends utilizing high frequency 4 kHz for the effective assessment and diagnosis of hearing loss caused by exposure to heavy metals.

Parenthood, spatial temporal environmental exposure, and leisure-time physical activity participation: Evidence from a micro-timescale retrospective longitudinal study

Parents with dependent children are at a high risk of physical inactivity. While previous studies have mostly focused on how parents' time constraints and changing social network may inhibit leisure time physical activity (LTPA) over the long-term, less is known about the integrated effects of parenting and spatial-temporal environmental exposure on the execution of LTPA during certain episodes of a day. By adopting an integrated social-spatiotemporal-environmental model (ST-ISEM) based on micro-timescale retrospective longitudinal analysis, we examine the association between LTPA participation and spatial-temporal environmental exposure at a micro-timescale, i.e., at the episode-level in working adults' workday, and specifically how parenting integrated with spatial-temporal environmental exposure can jointly influence episode-level LTPA participation. Using data from the day reconstruction method from 701 individuals in Shenzhen, China, we find that parenting may affect the participation of LTPA on workdays not only by shaping temporal environmental factors (time constraint path and social network path), but also by interacting with built environmental exposures (spatial path), both at the episode-level. This study contributes to the theorizing of an integrated social-environmental model for health and wellbeing by extending the ISEM from the life span to the micro-timescale and also by highlighting the importance of temporality in environmental exposure and health studies. It also contributes to the spatial temporal behavioral perspective of time geography literature by clarifying multiple pathways through which social and spatiotemporal environmental factors could interact and jointly affect health behaviors at a micro-timescale. This study contributes to the literature on parenting and LTPA decline by enriching and deepening the understanding of the time constraint and social network pathways through which parenting leads to LTPA change at the micro-timescale. While time constraints may decrease parents’ LTPA at long-term, increasing physical activities related to childcare after work may strongly obstruct moderate-to-vigorous LTPA at a micro-timescale. This study also identifies a spatial pathway by which parenting hinders LTPA due to changing understanding and usage of urban spaces. This pathway warrants attention from social epidemiologists, health geographers, and urban planners since existing interventions promoting physical activity in urban spaces may be ineffective for parents.

Becoming aWARE: The Development of a Web-Based Tool for Autism Research and the Environment.

A sharp rise in autism spectrum disorder (ASD) prevalence estimates, beginning in the 1990s, suggested factors additional to genetics were at play. This stimulated increased research investment in nongenetic factors, including the study of environmental chemical exposures, diet, nutrition, lifestyle, social factors, and maternal medical conditions. Consequently, both peer- and non-peer-reviewed bodies of evidence investigating environmental contributors to ASD etiology have grown significantly. The heterogeneity in the design and conduct of this research results in an inconclusive and unwieldy 'virtual stack' of publications. We propose to develop a Web-based tool for Autism Research and the Environment (aWARE) to comprehensively aggregate and assess these highly variable and often conflicting data. The interactive aWARE tool will use an approach for the development of systematic evidence maps (SEMs) to identify and display all available relevant published evidence, enabling users to explore multiple research questions within the scope of the SEM. Throughout tool development, listening sessions and workshops will be used to seek perspectives from the broader autism community. New evidence will be indexed in the tool annually, which will serve as a living resource to investigate the association between environmental factors and ASD.

Differential Participation, a Potential Cause of Spurious Associations in Observational Cohorts in Environmental Epidemiology.

Differential participation in observational cohorts may lead to biased or even reversed estimates. In this article, we describe the potential for differential participation in cohorts studying the etiologic effects of long-term environmental exposures. Such cohorts are prone to differential participation because only those who survived until the start of follow-up and were healthy enough before enrollment will participate, and many environmental exposures are prevalent in the target population and connected to participation via factors such as geography or frailty. The relatively modest effect sizes of most environmental exposures also make any bias induced by differential participation particularly important to understand and account for. We discuss key points to consider for evaluating differential participation and use causal graphs to describe two example mechanisms through which differential participation can occur in health studies of long-term environmental exposures. We use a real-life example, the Canadian Community Health Survey cohort, to illustrate the non-negligible bias due to differential participation. We also demonstrate that implementing a simple washout period may reduce the bias and recover more valid results if the effect of interest is constant over time. Furthermore, we implement simulation scenarios to confirm the plausibility of the two mechanisms causing bias and the utility of the washout method. Since the existence of differential participation can be difficult to diagnose with traditional analytical approaches that calculate a summary effect estimate, we encourage researchers to systematically investigate the presence of time-varying effect estimates and potential spurious patterns (especially in initial periods in the setting of differential participation).

Power and sample size analysis for longitudinal mixed models of health in populations exposed to environmental contaminants: a tutorial

BackgroundWhen evaluating the impact of environmental exposures on human health, study designs often include a series of repeated measurements. The goal is to determine whether populations have different trajectories of the environmental exposure over time. Power analyses for longitudinal mixed models require multiple inputs, including clinically significant differences, standard deviations, and correlations of measurements. Further, methods for power analyses of longitudinal mixed models are complex and often challenging for the non-statistician. We discuss methods for extracting clinically relevant inputs from literature, and explain how to conduct a power analysis that appropriately accounts for longitudinal repeated measures. Finally, we provide careful recommendations for describing complex power analyses in a concise and clear manner.MethodsFor longitudinal studies of health outcomes from environmental exposures, we show how to [1] conduct a power analysis that aligns with the planned mixed model data analysis, [2] gather the inputs required for the power analysis, and [3] conduct repeated measures power analysis with a highly-cited, validated, free, point-and-click, web-based, open source software platform which was developed specifically for scientists.ResultsAs an example, we describe the power analysis for a proposed study of repeated measures of per- and polyfluoroalkyl substances (PFAS) in human blood. We show how to align data analysis and power analysis plan to account for within-participant correlation across repeated measures. We illustrate how to perform a literature review to find inputs for the power analysis. We emphasize the need to examine the sensitivity of the power values by considering standard deviations and differences in means that are smaller and larger than the speculated, literature-based values. Finally, we provide an example power calculation and a summary checklist for describing power and sample size analysis.ConclusionsThis paper provides a detailed roadmap for conducting and describing power analyses for longitudinal studies of environmental exposures. It provides a template and checklist for those seeking to write power analyses for grant applications.

Technical note: Extending the SWAT model to transport chemicals through tile and groundwater flow

Abstract. The Soil and Water Assessment Tool (SWAT) is frequently used to simulate the transport of water-soluble chemicals in the environment such as pesticides and their metabolites originating from agricultural applications. However, the model does not simulate the transport of chemicals through subsurface tile drains and groundwater. This limitation is particularly significant in lowland regions and when simulating stable chemicals that can leach into and accumulate in groundwater. To fill this gap, the publicly available SWAT code was modified to complement the simulation of chemicals by adding transport capabilities through tile and groundwater flow. The extended model was tested in two agricultural catchments with a typically used pesticide and one of its metabolites. Results show that the transport of the pesticide is mainly governed by surface runoff and that shallow surface tile flow contributions can be significant. Metabolite concentrations in streamflow are, however, driven by a complex spatiotemporal interplay of all surface and subsurface transport components. This highlights the advantages of applying the modified code in catchment-scale environmental exposure studies and for developing best management practices or mitigation strategies. The new code is made available as an electronic supplement to this technical note.

Adding open spectral data to MassBank and PubChem using open source tools to support non-targeted exposomics of mixtures.

The term "exposome" is defined as a comprehensive study of life-course environmental exposures and the associated biological responses. Humans are exposed to many different chemicals, which can pose a major threat to the well-being of humanity. Targeted or non-targeted mass spectrometry techniques are widely used to identify and characterize various environmental stressors when linking exposures to human health. However, identification remains challenging due to the huge chemical space applicable to exposomics, combined with the lack of sufficient relevant entries in spectral libraries. Addressing these challenges requires cheminformatics tools and database resources to share curated open spectral data on chemicals to improve the identification of chemicals in exposomics studies. This article describes efforts to contribute spectra relevant for exposomics to the open mass spectral library MassBank (https://www.massbank.eu) using various open source software efforts, including the R packages RMassBank and Shinyscreen. The experimental spectra were obtained from ten mixtures containing toxicologically relevant chemicals from the US Environmental Protection Agency (EPA) Non-Targeted Analysis Collaborative Trial (ENTACT). Following processing and curation, 5582 spectra from 783 of the 1268 ENTACT compounds were added to MassBank, and through this to other open spectral libraries (e.g., MoNA, GNPS) for community benefit. Additionally, an automated deposition and annotation workflow was developed with PubChem to enable the display of all MassBank mass spectra in PubChem, which is rerun with each MassBank release. The new spectral records have already been used in several studies to increase the confidence in identification in non-target small molecule identification workflows applied to environmental and exposomics research.

Persistent Organic Pollutant Levels in Maternal and Cord Blood Plasma and Breast Milk: Results from the Rio Birth Cohort Pilot Study of Environmental Exposure and Childhood Development (PIPA Study).

Levels of polychlorinated biphenyls (PCB) and organochlorine pesticides (OCP) were evaluated in the breast milk and maternal and umbilical cord blood of pregnant women and their newborns in Rio de Janeiro, Brazil. The concentration of 11 PCB and 17 OCP were measured in 135 samples of maternal, and 116 samples of cord blood plasma, as well as 40, 47, and 45 samples of breast milk at 1st, 3rd, and 6th months after birth, respectively, using gas chromatography-mass spectrometry (GC-MS-MS). Women were asked to answer an enrollment questionnaire with reproductive, lifestyle, residential and sociodemographic questions. The most commonly detected OCPs and PCBs in the maternal and cord blood were 4,4'-DDE; β-HCH; ɣ-HCH; and PCB 28. 4,4'-DDE was also the most commonly detected OCP in breast milk samples. Although not statistically significant, ∑DDT levels were higher among women with pregestational BMI ≥ 30, and who were non-white and older (age > 40). Newborns with an Apgar score ≤ 8 at minute 5 of life showed significantly higher levels of ∑DDT in the cord blood. Persistent OCPs and PCBs were still detected in maternal and umbilical cord blood and breast milk, even after decades of their banishment in Brazil. They may pose a risk to maternal, fetal and children's health.

Association of Childhood Respiratory Status with Adult Occupational Exposures in a Birth Cohort.

Rationale: People with better early-life respiratory health may be more likely to work in occupations with high workplace exposures in adult life compared with people with poor respiratory health. This may manifest as a healthy worker effect bias, potentially confounding the analysis of environmental exposure studies. Objectives: To evaluate associations between lung function in adolescence and occupational exposures at initial adult employment. Methods: The TCRS (Tucson Children's Respiratory Study) is a long-term prospective study of respiratory health beginning at birth. Associations between respiratory function at age 11 years and occupational exposures at first job at age 26 years were evaluated with logistic regression. We calculated percentage predicted values for forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1:FVC ratio, and forced expiratory flow from 25% to 75% of vital capacity at age 11. At the 26-year visit, participants self-reported occupational exposures to dust, smoke, and fumes/gas at first job in a standardized interview. Results: Forced expiratory flow from 25% to 75% of vital capacity and FEV1:FVC ratio at age 11 were positively associated with dust workplace exposures at the first job. Each 10% increase in percentage predicted prebronchodilator FEV1:FVC ratio was associated with 30% higher odds of workplace dust exposure (odds ratio for a 1% increase, 1.03 [95% confidence interval, 1.00-1.06; P = 0.045]). Similar associations were observed for FEV1 and FVC with workplace smoke exposures. We also observed modification by time at job: associations were stronger for those who remained in their jobs longer than 12 months. In addition, those with better function at age 11 were more likely to stay in their jobs longer than 12 months if their first jobs involved exposure to dust. Conclusions: Childhood lung function affects initial career choice. This study supports the premise of the healthy worker effect.

Scoping report and interactive evidence map on studies of environmental exposures, psychosocial stressors, and cardiovascular diseases in disproportionally impacted communities

Background and Aim Worldwide, cardiovascular disease (CVD) is the leading cause of death, with two-thirds of CVD- related deaths occurring in low- and middle-income countries. In addition to socioeconomic status (SES), CVD rates vary by race, ethnicity, and place. Environmental Health disparities (EHD) are predominately caused by systematic racism leading to higher exposure to environmental toxins, higher indicators of psychosocial stress, and social inequities. Our goal is to inform the scientific community and disproportionally affected populations (DAP) on the scope of the literature on CVD EHD and identify research gaps. Methods To target relevant epidemiological studies and reviews, we searched PubMed using a broad range of terms for DAPs, environmental exposures, psychosocial stressors, and CVD outcomes. DAPs included racial, ethnic, and sexual minority groups and people with lower SES status or living in rural areas. Using exclusion/inclusion criteria, we screened the studies to determine relevancy. Included studies were reviewed and characterized by specific populations, environmental exposures, psychosocial stressors, and CVD outcomes. We visualized and explored the findings using six interactive evidence maps in Tableau. Results We identified >1,400 relevant primary studies on CVD and psychosocial stressors or environmental exposures; >800 were conducted in DAP. The most studied racial/ethnic population was Black people (>300), and there were very few studies on sexual minorities (<10). Most DAP studies reported on personal behaviors (>60%), air pollution (~35%), SES indicators, and hypertension (~55%) for all DAP; however, some patterns differ according to the DAP. About 20% of studies reported allostatic load, and 7% evaluated racism and CVD. A research gap is the evaluation of environmental-psychosocial stressors interactions and CVD. Conclusions Our evidence map is a resource for DAP and scientific communities to explore the state of the science on CVD EHD and can be used to develop health equity solutions. Keywords: EHD, CVD

Prenatal Exposure to Metals and Neurodevelopment in Infants at Six Months: Rio Birth Cohort Study of Environmental Exposure and Childhood Development (PIPA Project)

Prenatal Exposure to Metals and Neurodevelopment in Infants at Six Months: Rio Birth Cohort Study of Environmental Exposure and Childhood Development (PIPA Project)

Exposomic Analysis of Organic Pollutants in Seminal Plasma and Male Reproductive Parameters

Previous studies of environmental exposures and male reproductive health have typically examined limited sets of exposures in the urine, which may not accurately capture the chemical burden in relevant tissues and do not consider a large range of concurrent exposures. Here, we used a combined targeted and untargeted exposome approach to identify novel associations of environmental pollutants found in seminal plasma, as individual metabolites and co-exposure patterns, with male reproductive parameters. Semen samples were collected from male partners from 100 heterosexual couples undergoing assisted reproductive treatment in Tel Aviv after 2-7 day abstinence. Semen parameters were assessed for sperm concentration, percent motility, and total motile sperm. Using a novel QuEChERS (quick, easy, cheap, efficient, rugged, and safe) extraction method, 118 targeted and 2005 untargeted organic pollutant exposures were measured from seminal plasma using gas chromatography. We used linear regression, principal component pursuit (PCP), and Bayesian Kernel Machine Regression (BKMR) to estimate the associations of organic pollutants with semen parameters. Using an exposome-wide association approach, we found that etriadizole, a common pesticide, was negatively associated with total motile sperm (p<0.001), concentration (p=0.002), and percent motility (p=0.04). Using PCP, a machine learning pattern recognition approach, we derived a low-rank matrix with one major principal component. This principal component was primarily loaded by one phthalate (diethyl phthalate) and three PAHs (anthracene, pyrene, phenanthrene) and was associated with lower total sperm (p=0.03) and percent motility (p=0.05). BKMR results confirmed that as an overall mixture, these four pollutants were negatively associated with percent motility, although anthracene was not important to the mixture effect. Seminal plasma levels of etridiazole, diethyl phthalate, and polycyclic aromatic hydrocarbons (PAHs) are negatively associated with semen parameters. Future exposomic investigations using seminal plasma are warranted. Keywords: exposomics; exposome; seminal plasma; reproduction; reproductive health; semen; sperm; pesticide, etridiazole, phthalates, PAH

Increased self-reported sensitivity to environmental stimuli and its effects on perception of air quality and well-being.

In previous studies, negative associations were found between increased environmental sensitivity and general well-being as well as positive perception of air quality. However, only a few studies with partly inconsistent results examined this relation under exposure. They tried to determine whether people with increased environmental sensitivity react to real environmental conditions with changes in current well-being and perception of air quality. Pooled data from two single-blinded randomized controlled trials with different exposure levels were analyzed. Participants were exposed to different levels of volatile organic compounds (VOC) and carbon dioxide (CO₂) in the front part of a former in-service wide-body airplane inserted in a low-pressure chamber. Three exposure groups were created depending on the VOC/CO₂ levels: low, medium and high. Subjects repeatedly answered questions about their current mental well-being and about perception of air quality and odor intensity. Based on self-reported data the participants were classified into groups with low and higher environmental sensitivity. Data were evaluated using a 2 (environmental sensitivity) x 3 (exposure) ANCOVA with repeated measures. 503 individuals (221 females) participated (mean age: 42.8±14.5 years). Thereof, 166 individuals were assigned to the group with higher environmental sensitivity; they reported poorer psychological well-being regarding vitality (F (1,466)=16.42, p<.001***, partial η²=0.034) and vigilance (F (1,467)=7.82, p=.005**, partial η²=0.016) and rated the pleasantness of air quality (F (1,476)=7.55, p=.006**, partial η²=0.016) and air movement (F (1,474)=5.11, p=.024*, partial η²=0.011) worse than people in the low sensitivity group. Exposure levels showed no effects. No systematic differences between men and women were found. Increased environmental sensitivity shared common variance with negative affectivity, another person-related variable. Its explanatory power was higher for evaluations of the environment whereas no differences between the concepts in explaining current psychological well-being were found. Even a slightly elevated level of environmental sensitivity led to worse ratings of the environment with no clear relation to the real environment. Consequently, environmental sensitivity should be considered as a confounding factor in environmental exposure studies. The independency from real exposure levels is in line with the results from previous studies showing that the differences in environmental ratings are probably also driven by psychological factors.

Arsenic and heavy metal concentrations in human hair from urban areas

Background: As concentrations of heavy metals in hair can reflect both metals exposure and intake concentrations, hair sample analysis is widely applied in forensic sciences, evaluation of environmental or occupational exposure and other studies. The aim of this study was to evaluate the concentrations of As, Cd, Pb, Cr, Cu, Co, Mn, Zn, Fe and Ni in the scalp hair of an urban population from Kermanshah in western Iran. Methods: In the present research, 30 points of the city were selected for human scalp hair sampling. Samples were taken from healthy inhabitants (aged 6 to 46 years) in Kermanshah city. Multivariate analysis method was applied to distinguish the anthropogenic and natural sources of heavy metals. Levels of elements in the scalp hair were measured by ICP-MS. Results: The mean concentrations of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb and As were 33.53±9.05, 27.98±7.77, 203.18±22.31, 1.94±0.85, 18.44±3.40, 107.11±22.56, 119.21±10.52, 0.97±0.36, 60.27±13.84, and 0.34±0.51 µg/g in the urban area, respectively. The highest concentration of all elements was found in the age group of 31-40 and 41-50 years except Fe, the maximum concentration of which was found in the age group of 6-20 years. Significant differences were found between smokers and non-smokers. Conclusion: Comparison of the heavy metals concentrations in the scalp hair of this area showed that the concentrations of the elements were clearly higher than those reported in other studies. However, the high concentrations of the elements in hair indicated that the inhabitants in the urban areas of Kermanshah might be at risk of exposure to high levels of toxic elements.

Assessing urinary phenol and paraben mixtures in pregnant women with and without gestational diabetes mellitus: A case-control study

Prior studies have identified the associations between environmental phenol and paraben exposures and increased risk of gestational diabetes mellitus (GDM), but no study addressed these exposures as mixtures. As methods have emerged to better assess exposures to multiple chemicals, our study aimed to apply Bayesian kernel machine regression (BKMR) to evaluate the association between phenol and paraben mixtures and GDM.This study included 64 GDM cases and 237 obstetric patient controls from the University of Oklahoma Medical Center. Mid-pregnancy spot urine samples were collected to quantify concentrations of bisphenol A (BPA), benzophenone-3, triclosan, 2,4-dichlorophenol, 2,5-dichlorophenol, butylparaben, methylparaben, and propylparaben. Multivariable logistic regression was used to evaluate the associations between individual chemical biomarkers and GDM while controlling for confounding. We used probit implementation of BKMR with hierarchical variable selection to estimate the mean difference in GDM probability for each component of the phenol and paraben mixtures while controlling for the correlation among the chemical biomarkers.When analyzing individual chemicals using logistic regression, benzophenone-3 was positively associated with GDM [adjusted odds ratio (aOR) per interquartile range (IQR) = 1.54, 95% confidence interval (CI) 1.15, 2.08], while BPA was negatively associated with GDM (aOR 0.61, 95% CI 0.37, 0.99). In probit-BKMR analysis, an increase in z-score transformed log urinary concentrations of benzophenone-3 from the 10th to 90th percentile was associated with an increase in the estimated difference in the probability of GDM (0.67, 95% Credible Interval 0.04, 1.30), holding other chemicals fixed at their medians. No associations were identified between other chemical biomarkers and GDM in the BKMR analyses.We observed that the association of BPA and GDM was attenuated when accounting for correlated phenols and parabens, suggesting the importance of addressing chemical mixtures in perinatal environmental exposure studies. Additional prospective investigations will increase the understanding of the relationship between benzophenone-3 exposure and GDM development.