Exposure characteristics and cumulative risk assessment of bisphenol A and its substitutes: the Taiwan environmental survey for toxicants 2013.

Introduction: Ever since the use of bisphenol A (BPA) has been restricted, concerns have been raised regarding the use of its substitutes, such as bisphenol S (BPS) and bisphenol F (BPF). Meanwhile, the EU European Food Safety Authority (EFSA) issued the new tolerable daily intake (TDI) after the latest re-risk assessment for BPA, which enforced the need for cumulative risk assessment in the population. This study was conducted to identify BPA and its substitute's exposure characteristics of the general Taiwanese population and estimate the cumulative risk of bisphenol exposure. Methods: Urine samples (N = 366 [adult, 271; minor, 95]) were collected from individuals who participated in the Taiwan Environmental Survey for Toxicants 2013. The samples were analyzed for BPA, BPS, and BPF through ultraperformance liquid chromatography-tandem mass spectrometry. Daily intake (DI) levels were calculated for each bisphenol. Hazard quotients (HQs) were calculated with the consideration of tolerable DI and a reference dose. Additionally, hazard index (HI; sum of HQs for each bisphenol) values were calculated. Results: Our study found that the median level of BPA was significantly higher in adults (9.63 µg/g creatinine) than in minors (6.63 µg/g creatinine) (p < 0.001). The DI of BPS was higher in female (0.69 ng/kg/day) than in male (0.49 ng/kg/day); however, the DIs of BPF and BPS were higher in boys (1.15 and 0.26 ng/kg/day, respectively) than in girls (0.57 and 0.20 ng/kg/day, respectively). Most HI values exceeded 1 (99% of the participants) after EFSA re-establish the TDI of BPA. Discussion: Our study revealed that the exposure profiles and risk of BPA and its substitute in Taiwanese varied by age and sex. Additionally, the exposure risk of BPA was deemed unacceptable in Taiwan according to new EFSA regulations, and food contamination could be the possible source of exposure. We suggest that the risk of exposure to BPA and its substitutes in most human biomonitoring studies should be reassessed based on new scientific evidence.

Diabetes mellitus and serum organochlorine pesticides mixtures in Mexican women.

BACKGROUND: Very recently, it has been reported that exposure to different mixtures of organochlorine pesticides (OCP) is associated with the development of diabetes mellitus (DM). In Mexico, DM is a public health problem that might be related to the historical intense use of OCP. We aimed to evaluate, the association between DM and serum concentrations of OCP mixtures, and identify the main contributors within them. METHODS: We conducted a secondary cross-sectional analysis on the control group from a breast cancer population-based case-control study conducted from 2007 to 2011 in Northern Mexico. We identified 214 self-reported diabetic women and 694 non-diabetics. We obtained direct information about sociodemographic, lifestyle and reproductive characteristics. We determined 24 OCP and metabolites in serum by gas chromatography using an electron capture micro detector. We used Weighted Quantile Sum regression to assess the association of DM and exposure to multiple OCP, and the contribution of each compound within the mixture. RESULTS: We found a positive adjusted association between DM and an OCP mixture (OR: 2.63, 95%CI: 1.85, 3.74), whose primary contribution arose from p, p'-DDE (mean weight 23.3%), HCB (mean weight 17.3%), trans nonachlor (mean weight 15.4%), o, p'-DDE (mean weight 7.3%), heptachlor epoxide (mean weight 5.9%), oxychlordane (mean weight 4.7%), and heptachlor (mean weight 4.5%). In addition, these OCP along with p, p'-DDT and cis chlordane, were of concern and remained associated when excluding hypertensive women from the analysis (OR 2.55; 95% CI 1.56, 4.18). CONCLUSIONS: Our results indicate, for the first time in a Latin-American population, that the concomitant exposure to multiple OCP is associated with DM. Further research is needed since the composition of OCP mixtures may vary according to regional pesticides use patterns.

Long-term trends (compared to the pre-war period) and public health impact of surface ozone in Ukraine.

OBJECTIVE: Aim: To analyze the dynamics of ambient air pollution by surface O3 (in pre-war and wartime periods) and assess its impact on public health in order to provide proposals aimed at developing preventive programs. PATIENTS AND METHODS: Materials and Methods: Physical and chemical methods of analysis (О3 - gas analyzers APDA-370 HORIBA, meteorological sensor WS-600); health risk assessment (AirQ+); statistical data processing methods (StatSoft STATISTICA 10.0 portable, MicrosoftR Excel). RESULTS: Results: Air quality monitoring in peak season 2021 and 2022 detected exceedances of the daily maximum 8-hour ozone (O3) concentration. This resulted in a health risk for the exposed population during 70 % (174 days) and 84 % (181 days) of observations, respectively. The maximum exceedance levels were 1.7 and 2.1 times higher than the recommended limit. Estimated number of excess cases of natural and respiratory mortality in the population over 30 years due to long-term O3 exposure: 227 (95 % CI: 0; 450) and 22 (95 % CI: 0; 54), respectively. Predictive assessments of ozone (O3) air pollution's impact during wartime activities suggest an average increase of 40 % in additional deaths from non-communicable diseases. CONCLUSION: Conclusions: Obtained results can serve as a basis for development of medical and environmental measures aimed at implementing adaptation proposals for public health in conditions of global climate change and wartime.

Metal concentrations and KIM-1 levels in school-aged children: a cross-sectional study.

Environmental exposure to heavy metals and metalloids, originating from sources such as mining and manufacturing activities, has been linked to adverse renal effects. This cross-sectional study assessed children's exposure to these elements and its association with urinary kidney injury molecule-1 (KIM-1). We analyzed data from 99 school-aged children residing in nine localities within the state of Colima, Mexico, during the latter half of 2023. Levels of 23 metals/metalloids and urinary KIM-1 were measured using inductively coupled plasma mass spectrometry (ICP-MS) and enzyme-linked immunosorbent assay, respectively. Detectable levels of these contaminants were found in over 91% of participants, with varied exposure profiles observed across locations ( p = 0.019). After adjusting for confounding factors like gender, age, and locality, higher levels of six metals/metalloids (boron, cadmium, cesium, lithium, selenium, zinc) were significantly associated with increased KIM-1 levels. Tailored mitigation efforts are crucial to protect children from regional pollutant burdens. However, limitations exist, as our study did not capture all potential factors influencing heavy metal/metalloid and KIM-1 levels.

Accommodating detection limits of multiple exposures in environmental mixture analyses: an overview of statistical approaches.

BACKGROUND: Identifying the impact of environmental mixtures on human health is an important topic. However, such studies face challenges when exposure measurements lie below limit of detection (LOD). While various approaches for accommodating a single exposure subject to LOD have been used, their impact on mixture analysis has not been thoroughly investigated. Our study aims to understand the impact of five popular LOD accommodation approaches on mixture analysis results with multiple exposures subject to LOD, including omitting subjects with any exposures below LOD (complete case analysis); single imputations by LOD/ 2 , and by estimates from a censored accelerated failure time (AFT) model; and multiple imputation (MI) with or without truncation based on LOD. METHODS: In extensive simulation studies with high-dimensional and highly correlated exposures and a continuous health outcome, we examined the performance of each LOD approach on three mixture analysis methods: elastic net regression, weighted quantile sum regression (WQS) and Bayesian kernel machine regression (BKMR). We further analyzed data from the National Health and Nutrition Examination Survey (NHANES) on how persistent organic pollutants (POPs) influenced leukocyte telomere length (LTL). RESULTS: Complete case analysis was inefficient and could result in severe bias for some mixture methods. Imputation by LOD/ 2 showed unstable performance across mixture methods. Conventional MI was associated with consistent mild biases, which can be reduced by using a truncated distribution for imputation. Estimating censored values by AFT models had a minimal impact on the results. In the NHANES analysis, imputation by LOD/ 2 , truncated MI and censored AFT models performed similarly, with a positive overall effect of POPs on LTL while PCB126, PCB169 and furan 2,3,4,7,8-pncdf being the most important exposures. CONCLUSIONS: Our study favored using truncated MI and censored AFT models to accommodate values below LOD for the stability of downstream mixture analysis.

Decabromodifenyl Ether (BDE-209) in Surface Soils from Warsaw and Surrounding Areas: Characterization of Non-Carcinogenic Risk Associated with Oral and Dermal Exposure.

Polybrominated diphenyl ethers (PBDEs) have been used for many years as flame retardants. Due to their physicochemical and toxicological properties, they are considered to be persistent organic pollutants (POPs). BDE-209 is the main component of deca-BDE, the one PBDE commercial mixture currently approved for use in the European Union. The aim of this study was to analyse BDE-209 in surface soil samples from Warsaw and surrounding areas (Poland) as an indicator of environmental pollution with PBDEs, and to characterise the associated health risk. A total of 40 samples were analysed using gas chromatography with electron capture detection (GC-µECD). Concentrations of BDE-209 in soil ranged from 0.4 ng g-1 d.w. (limit of quantification) to 158 ng g-1 d.w. Overall, 52.5% of results were above the method's limit of quantification. The highest levels were found at several locations with heavy traffic and in the vicinity of a CHP plant in the city. The lowest concentrations were observed in most of the samples collected from low industrialized or green areas (<0.4 to 1.68 ng g-1 d.w.). Exposure to BDE-209 was estimated for one of the most sensitive populations, i.e., young children. The following exposure routes were selected: oral and dermal. No risk was found to young children's health.

Model misspecification, measurement error, and apparent supralinearity in the concentration-response relationship between PM2.5 and mortality.

A growing number of studies have produced results that suggest the shape of the concentration-response (C-R) relationship between PM2.5 exposure and mortality is "supralinear" such that incremental risk is higher at the lowest exposure levels than at the highest exposure levels. If the C-R function is in fact supralinear, then there may be significant health benefits associated with reductions in PM2.5 below the current US National Ambient Air Quality Standards (NAAQS), as each incremental tightening of the PM2.5 NAAQS would be expected to produce ever-greater reductions in mortality risk. In this paper we undertake a series of tests with simulated cohort data to examine whether there are alternative explanations for apparent supralinearity in PM2.5 C-R functions. Our results show that a linear C-R function for PM2.5 can falsely appear to be supralinear in a statistical estimation process for a variety of reasons, such as spatial variation in the composition of total PM2.5 mass, the presence of confounders that are correlated with PM2.5 exposure, and some types of measurement error in estimates of PM2.5 exposure. To the best of our knowledge, this is the first simulation-based study to examine alternative explanations for apparent supralinearity in C-R functions.

Radon Exposure Assessment in Occupational and Environmental Settings: An Overview of Instruments and Methods.

Radon is a naturally occurring noble radioactive gas that poses significant health risks, particularly lung cancer, due to its colorless, odorless, and tasteless nature, which makes detection challenging without formal testing. It is found in soil, rock, and water, and it infiltrates indoor environments, necessitating regulatory standards and guidelines from organizations such as the Environmental Protection Agency, the World Health Organization, and the Occupational Health and Safety Agency to mitigate exposure. In this paper, we present various methods and instruments for radon assessment in occupational and environmental settings. Discussion on long- and short-term monitoring, including grab sampling, radon dosimetry, and continuous real-time monitoring, is provided. The comparative analysis of detection techniques-active versus passive-is highlighted from real-time data and long-term exposure assessment, including advances in sensor technology, data processing, and public awareness, to improve radon exposure evaluation techniques.

Environmental phenol exposures in 6- to 12-week-old infants: The Infant Feeding and Early Development (IFED) study.

BACKGROUND: Exposure to phenols, endocrine-disrupting chemicals used in personal care and consumer products, is widespread. Data on infant exposures are limited despite heightened sensitivity to endocrine disruption during this developmental period. We aimed to describe distributions and predictors of urinary phenol concentrations among U.S. infants ages 6-12 weeks. METHODS: The Infant Feeding and Early Development (IFED) study is a prospective cohort study of healthy term infants enrolled during 2010-2013 in the Philadelphia region. We measured concentrations of seven phenols in 352 urine samples collected during the 6- or 8- and/or 12-week study visits from 199 infants. We used linear mixed models to estimate associations of maternal, sociodemographic, infant, and sample characteristics with natural-log transformed, creatinine-standardized phenol concentrations and present results as mean percent change from the reference level. RESULTS: Median concentrations (µg/L) were 311 for methylparaben, 10.3 for propylparaben, 3.6 for benzophenone-3, 2.1 for triclosan, 1.0 for 2,5-dichlorophenol, 0.7 for BPA, and 0.3 for 2,4-dichlorophenol. Geometric mean methylparaben concentrations were approximately 10 times higher than published estimates for U.S. children ages 3-5 and 6-11 years, while propylparaben concentrations were 3-4 times higher. Infants of Black mothers had higher concentrations of BPA (83%), methylparaben (121%), propylparaben (218%), and 2,5-dichorophenol (287%) and lower concentrations of benzophenone-3 (-77%) and triclosan (-53%) than infants of White mothers. Triclosan concentrations were higher in breastfed infants (176%) and lower in infants whose mothers had a high school education or less (-62%). Phenol concentrations were generally higher in summer samples. CONCLUSIONS: Widespread exposure to select environmental phenols among this cohort of healthy U.S. infants, including much higher paraben concentrations compared to those reported for U.S. children, supports the importance of expanding population-based biomonitoring programs to infants and toddlers. Future investigation of exposure sources is warranted to identify opportunities to minimize exposures during these sensitive periods of development.

Insight Study of Trace Elements in PM2.5 During Nine Years in Delhi, India: Seasonal Variation, Source Apportionment, and Health Risks Assessment.

This study investigated the concentrations, seasonal variations, sources, and human health risks associated with exposure to heavy elements (As, Al, Pb, Cr, Mn, Cu, Zn, and Ni) of PM2.5 at an urban location of Delhi (28° 38' N, 77° 10' E; 218 m amsl), India, from January 2013 to December 2021. The average mass concentration of PM2.5 throughout the study period was estimated as 127 ± 77 µg m-3, which is exceeding the National Ambient Air Quality Standards (NAAQS) limit (annual: 40 µg m-3; 24 h: 60 µg m-3). The seasonal mass concentrations of PM2.5 exhibited at the order of post-monsoon (192 ± 110 µgm-3) > winter (158 ± 70 µgm-3) > summer (92 ± 44 µgm-3) and > monsoon (67 ± 32 µgm-3). The heavy elements, Al (1.19 µg m-3), Zn (0.49 µg m-3), Pb (0.43 µg m-3), Cr (0.21 µg m-3), Cu (0.21 µg m-3), Mn (0.07 µg m-3), and Ni (0.14 µg m-3) exhibited varying concentrations in PM2.5, with the highest levels observed in the post-monsoon season, followed by winter, summer, and monsoon seasons. Six primary sources throughout the study period, contributing to PM2.5 were identified by positive matrix factorization (PMF), such as dust (paved/crustal/soil dust: 29.9%), vehicular emissions (17.2%), biomass burning (15.4%), combustion (14%), industrial emissions (14.2%), and Br-rich sources (9.2%). Health risk assessments, including hazard quotient (HQ), hazard index (HI), and carcinogenic risk (CR), were computed based on heavy elements concentrations in PM2.5. Elevated HQ values for Cr and Mn linked with adverse health impacts in both adults and children. High carcinogenic risk values were observed for Cr in both adults and children during the winter and post-monsoon seasons, as well as in adults during the summer and monsoon seasons. The combined HI value exceeding one suggests appreciable non-carcinogenic risks associated with the examined elements. The findings of this study provide valuable insights into the behaviour and risk mitigation of heavy elements in PM2.5, contributing to the understanding of air quality and public health in the urban environment of Delhi.

Sources, trigger points, and effect size of associations between PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) and fractional exhaled nitric oxide (FeNO): A panel study with 16 follow-up visits over 4 years.

Exposure to fine particulate matter (PM2.5) is a significant concern for respiratory health. However, the sources, trigger points, and effect size of specific associations between PM2.5 components, particularly polycyclic aromatic hydrocarbons (PAHs) and the airway inflammatory marker fractional exhaled nitric oxide (FeNO) have not been fully explored. In this study, 69 healthy college students were enrolled and followed up 16 times from 2014 to 2018. Individual FeNO was measured and ambient air PM2.5 samples were collected for 7 consecutive days before each follow-up. PAHs were quantified using Gas Chromatography-Mass Spectrometry. Linear mixed-effect regression models were employed to evaluate the associations between PM2.5-bound PAHs and FeNO. Additionally, PMF (Positive Matrix Factorization) was utilized to identify sources of PM2.5-bound PAHs and assess their impact on FeNO. Throughout the study, the average (SD) of ΣPAHs concentrations was 78.50 (128.9) ng/m3. PM2.5 and PM2.5-bound PAHs were significantly associated with FeNO at various lag days. Single-day lag analyses revealed maximum effects of PM2.5 on FeNO, with an increase of 7.71% (95% CI: 4.67%, 10.83%) per interquartile range (IQR) (48.10 µg/m3) increase of PM2.5 at lag2, and ΣPAHs showed a maximum elevation in FeNO of 6.40% (95% CI: 2.33%, 10.63%) at lag4 per IQR (57.39 ng/m3) increase. Individual PAHs exhibited diversity peak effects on FeNO at lag3 (6 of 17), lag4 (9 of 17) in the single-day model, and lag0-5 (8 of 17) (from lag0-1 to lag0-6) in the cumulative model. Source apportionment indicated coal combustion as the primary contributor (accounting for 30.7%). However, a maximum effect on FeNO (an increase of 21.57% (95% CI: 13.58%, 30.13%) per IQR increase) was observed with traffic emissions at lag4. The findings imply that strategic regulation of particular sources of PAHs, like traffic emissions, during specific periods could significantly contribute to safeguarding public health.

High-sensitivity liquid chromatography-tandem mass spectrometry quantitative for alkyl imidazolium ionic liquids in human serum: Advancing biomonitoring of human exposure concerns.

Alkyl imidazolium ionic liquids (Cn[MIM]), initially heralded as eco-friendly green solvents for diverse industrial applications, have increasingly been recognized fortheir biodegradability challenges and multiple biotoxicity. Despite potential health risks, research into the effects of Cn[MIM] on human health remains scarce, particularly regarding their detection in biological serum samples. This study validated a matrix-matched calibration quantitative method that utilizes solid-phase extraction (SPE) coupled with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The method was used to analyze the presence of 10 ionic liquids (ILs) with varying alkyl carbon chain lengths (C2-C12) across 300 human serum samples. Efficient separation was achieved using optimized SPE conditions and a BEH C18 column with an appropriate mobile phase. Results demonstrated a strong linear relationship (0.05-100 ng/mL; R2 = 0.995-0.999), with detection and quantification limits with detection and quantification limits ranging from 0.001 to 0.107 ng/mL and 0.003-0.355 ng/mL, respectively. Intraday and inter-day precisions were 0.85-6.99 % and 1.50-7.46 %, with recoveries between 82 and 113 %. The validated method detected C6MIM in 19 % of samples and C8MIM in 8.3 % of samples, with concentrations ranging from 0.02 to 111.70 µg/L and 0.09-16.99 µg/L, respectively, suggesting a potential risk of human exposure. This underscores the importance of robust detection methods in monitoring environmental and human health impacts of alkyl imidazolium compounds.

In Vitro and In Vivo Biotransformation Profiling of 6PPD-Quinone toward Their Detection in Human Urine.

The antioxidant N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and its oxidized quinone product 6PPD-quinone (6PPD-Q) in rubber have attracted attention due to the ecological risk that they pose. Both 6PPD and 6PPD-Q have been detected in various environments that humans cohabit. However, to date, a clear understanding of the biotransformation of 6PPD-Q and a potential biomarker for exposure in humans are lacking. To address this issue, this study presents a comprehensive analysis of the extensive biotransformation of 6PPD-Q across species, encompassing both in vitro and in vivo models. We have tentatively identified 17 biotransformation metabolites in vitro, 15 in mice in vivo, and confirmed the presence of two metabolites in human urine samples. Interestingly, different biotransformation patterns were observed across species. Through semiquantitative analysis based on peak areas, we found that almost all 6PPD-Q underwent biotransformation within 24 h of exposure in mice, primarily via hydroxylation and subsequent glucuronidation. This suggests a rapid metabolic processing of 6PPD-Q in mammals, underscoring the importance of identifying effective biomarkers for exposure. Notably, monohydroxy 6PPD-Q and 6PPD-Q-O-glucuronide were consistently the most predominant metabolites across our studies, highlighting monohydroxy 6PPD-Q as a potential key biomarker for epidemiological research. These findings represent the first comprehensive data set on 6PPD-Q biotransformation in mammalian systems, offering insights into the metabolic pathways involved and possible exposure biomarkers.

Early childhood exposures to phthalates in association with attention-deficit/hyperactivity disorder behaviors in middle childhood and adolescence in the ReCHARGE study.

BACKGROUND: Early-life exposure to phthalates alters behaviors in animals. However, epidemiological evidence on childhood phthalate exposure and attention-deficit/hyperactivity disorder (ADHD) behaviors is limited. METHODS: This study included 243 children from the ReCHARGE (Revisiting Childhood Autism Risks from Genetics and Environment) study, who were previously classified as having autism spectrum disorder (ASD), developmental delay, other early concerns, and typical development in the CHARGE case-control study. Twenty phthalate metabolites were measured in spot urine samples collected from children aged 2-5 years. Parents reported on children's ADHD symptoms at ages 8-18 years using Conners-3 Parent Rating Scale. Covariate-adjusted negative binomial generalized linear models were used to investigate associations between individual phthalate metabolite concentrations and raw scores. Weighted quantile sum (WQS) regression with repeated holdout validation was used to examine mixture effects of phthalate metabolites on behavioral scores. Effect modification by child sex was evaluated. RESULTS: Among 12 phthalate metabolites detected in >75% of the samples, higher mono-2-heptyl phthalate (MHPP) was associated with higher scores on Inattentive (ß per doubling = 0.05, 95% confidence interval [CI]: 0.02, 0.08) and Hyperactive/Impulsive scales (ß = 0.04, 95% CI: 0.00, 0.07), especially among children with ASD. Higher mono-carboxy isooctyl phthalate (MCiOP) was associated with higher Hyperactivity/Impulsivity scores (ß = 0.07, 95% CI: -0.01, 0.15), especially among typically developing children. The associations of the molar sum of high molecular weight (HMW) phthalate metabolites and a phthalate metabolite mixture with Hyperactivity/Impulsivity scores were modified by sex, showing more pronounced adverse associations among females. CONCLUSION: Exposure to phthalates during early childhood may impact ADHD behaviors in middle childhood and adolescence, particularly among females. Although our findings may not be broadly generalizable due to the diverse diagnostic profiles within our study population, our robust findings on sex-specific associations warrant further investigations.

Human biomonitoring follow-up study on PFOA contamination and investigation of possible influencing factors on PFOA exposure in a German population originally exposed to emissions from a fluoropolymer production plant.

BACKGROUND: In the past, perfluorooctanoic acid (PFOA) was produced and applied as an emulsifier in a fluoropolymer production plant in the Altötting district, southern Bavaria (Germany). This chemical was released directly into the environment, resulting in the contamination of the local drinking water. During a human biomonitoring (HBM) survey in 2018, increased median PFOA blood serum levels, compared to a normally exposed control group with no known source of PFOA exposure from Munich, Germany, were detected in the resident population (23.18 µg/l in the general population, 20.71 µg/l in the children's group). The follow-up study aimed to investigate whether purification of the drinking water as the main PFOA exposure source has been successful in reducing internal PFOA exposure and to estimate the association of internal PFOA exposure with possible influencing factors. METHODS: Only individuals who had already participated in the HBM study in 2018 were included. For the determination of the PFOA serum concentration, 5 ml of blood was drawn from each participating person. Blood samples were collected in the period from June to August 2022. Furthermore, information on sociodemographic characteristics, health status, dietary behaviour and other lifestyle factors were collected by means of a self-administered questionnaire. To examine the association of PFOA blood serum levels with possible influencing factors, such as age, gender and consumption of fish and game meat, a logistic regression model with a PFOA value > 10 µg/l as outcome was used. RESULTS: A total of 764 individuals participated in the follow-up study in 2022. Analyses were performed separately for the general population (n = 559), women of reproductive age (15-49 years old) (n = 120), and children under 12 years old (n = 30). Median PFOA blood levels have decreased by 56.9% in the general population, by 59.8% in the group of women of reproductive age and by 73.4% in the group of children under 12 years old. In the general population, a higher probability of a PFOA value > 10 µg/l was found for those aged 40-59 years (Odds ratio (OR) = 2.33 (95%CI: 1.23 to 4.43, p = 0.01) and those aged 60 years and older (OR = 5.32, 95%CI: 2.78 to 10.19, p < 0.001). CONCLUSIONS: In all study groups, the median PFOA serum levels decreased as expected after a half-life of four years, which confirms that contamination via drinking water has ceased. Furthermore, our study identified age as a significant predictor of internal PFOA exposure, while no influence was found for the consumption of fish and game meat. Further investigations are needed to quantify in a more detailed way the influence of dietary habits on PFOA exposure.

Human molybdenum exposure risk in industrial regions of China: New critical effect indicators and reference dose.

Evidence increasingly suggests molybdenum exposure at environmental levels is still associated with adverse human health, emphasizing the necessity to establish a more protective reference dose (RfD). Herein, we conducted a study measuring 15 urinary metals and 30 clinical health indicators in 2267 participants residing near chemical enterprises across 11 Chinese provinces to investigate their relationships. The kidney and cystatin-C emerged as the most sensitive organ and critical effect indicator of molybdenum exposure, respectively. Odds of cystatin-C-defined chronic kidney disease (CKD) in the highest quantile of molybdenum exposure significantly increased by 133.5% (odds ratio [OR]: 2.34, 95% CI: 1.78, 3.11) and 75.8% (OR: 1.76, 95% CI: 1.24, 2.49) before and after adjusting for urinary 14 metals, respectively. Intriguingly, cystatin-C significantly mediated 15.9-89.5% of molybdenum's impacts on liver and lung function, suggesting nephrotoxicity from molybdenum exposure may trigger hepatotoxicity and pulmonary toxicity. We derived a new RfD for molybdenum exposure (0.87 µg/kg-day) based on cystatin-C-defined estimated glomerular filtration rate by employing Bayesian Benchmark Dose modeling analysis. This RfD is significantly lower than current exposure guidance values (5-30 µg/kg-day). Remarkably, >90% of participants exceeded the new RfD, underscoring the significant health impacts of environmental molybdenum exposure on populations in industrial regions of China.

Phthalate exposure and subfecundity in preconception couples: A nested case-control study.

BACKGROUND: Phthalates (PAEs) are endocrine-disrupting chemicals ubiquitously found in the environment. This study aimed to examine the association between exposure of PAEs and subfecundity in preconception couples. METHODS: This is a nested case-control study based on preconception cohort. Preconception couples with intention to conceive were enrolled and followed up until a clinically confirmed pregnancy or 12 menstrual cycles of preparation for conception. A total of 107 couples with subfecundity- time to pregnancy (TTP) more than 12 menstrual cycles, and 144 couples ≤12 cycles were included in the analysis. The levels of PAE metabolites in one spot urine samples were detected and compared between the groups. The weighted quantile sum (WQS) regression model and Bayesian kernel machine regression (BKMR) model were used to examine the joint effects of couples' exposure to PAEs on subfecundity. RESULTS: Using the multivariate binary logistic regression model, compared to the lowest quartile of urinary ∑PAEs concentration group, both preconception females (aOR=2.42, 95% CI: 1.10-5.30, p=0.027) and males (aOR=2.99, 95% CI: 1.36-6.58, p=0.006) in the highest quartile group had an increased risk of subfecundity, and a dose-response relationship was observed between PAEs and the risk of subfecundity. The WQS analyses found that co-exposure to PAE mixture was a risk factor for subfecundity in preconception female (aOR=1.76, 95% CI: 1.38-2.26, p<0.001), male (aOR=1.58, 95% CI: 1.20-2.08, p=0.001), and couple (aOR=2.39, 95% CI: 1.61-3.52, p<0.001). The BKMR model found a positive combined effect of mixed exposure to PAEs on the risk of subfecundity. CONCLUSIONS: PAEs increase the risk of subfecundity in preconception couples. Our research reinforced the need of monitoring PAE exposure for the purpose of improving human reproductive health.

Systematic evidence mapping of potential correlates of exposure for per- and poly-fluoroalkyl substances (PFAS) based on measured occurrence in biomatrices and surveys of dietary consumption and product use.

Per- and poly-fluoroalkyl substances (PFAS) are widely observed in environmental media and often are found in indoor environments as well as personal-care and consumer products. Humans may be exposed through water, food, indoor dust, air, and the use of PFAS-containing products. Information about relationships between PFAS exposure sources and pathways and the amounts found in human biomatrices can inform source-contribution assessments and provide targets for exposure reduction. This work collected and collated evidence for correlates of PFAS human exposure as measured through sampling of biomatrices and surveys of dietary consumption and use of consumer products and articles. A systematic evidence mapping approach was applied to perform a literature search, conduct title-abstract and full-text screening, and to extract primary data into a comprehensive database for 16 PFAS. Parameters of interest included: sampling dates and locations, cohort descriptors, PFAS measured in a human biomatrix, information about food consumption in 11 categories, use of products/articles in 11 categories, and reported correlation values (and their statistical strength). The literature search and screening process yielded 103 studies with information for correlates of PFAS exposures. Detailed data were extracted and compiled on measures of PFAS correlations between biomatrix concentrations and dietary consumption and other product/article use. A majority of studies (61/103; 59%) were published after 2015 with few (8/103; 8%) prior to 2010. Studies were most abundant for dietary correlates (n = 94) with fewer publications reporting correlate assessments for product use (n = 56), while some examined both. PFOA and PFOS were assessed in almost all studies, followed by PFHxS, PFNA, and PFDA which were included in >50% of the studies. No relevant studies included PFNS or PFPeS. Among the 94 studies of dietary correlates, significant correlations were reported in 83% of the studies for one or more PFAS. The significant dietary correlations most commonly were for seafood, meats/eggs, and cereals/grains/pulses. Among the 56 studies of product/article correlates, significant correlations were reported in 70% of the studies. The significant product/article correlations most commonly were for smoking/tobacco, cosmetics/toiletries, non-stick cookware, and carpet/flooring/furniture and housing. Six of 11 product/article categories included five or fewer studies, including food containers and stain- and water-resistant products. Significant dietary and product/article correlations most commonly were positive. Some studies found a mix of positive and negative correlations depending on the PFAS, specific correlate, and specific response level, particularly for fats/oils, dairy consumption, food containers, and cosmetics/toiletries. Most of the significant findings for cereals/grains/pulses were negative correlations. Substantial evidence was found for correlations between dietary intake and biomatrix levels for several PFAS in multiple food groups. Studies examining product/article use relationships were relatively sparse, except for smoking/tobacco, and would benefit from additional research. The resulting database can inform further assessments of dietary and product use exposure relationships and can inform new research to better understand PFAS source-to-exposure relationships. The search strategy should be extended and implemented to support living evidence review in this rapidly advancing area.

Organochlorine pesticide contamination of soils and dust from an urban environment in the Niger Delta of Nigeria.

The concentrations, sources, and risk of twenty organochlorine pesticides (OCPs) in soils and dusts from a typical urban setting in the Niger Delta of Nigeria were examined. The Σ20 OCP concentrations (ng g-1) varied from 4.49 to 150 with an average value of 32.6 for soil, 4.67 to 21.5 with an average of 11.7 for indoor dust, and 1.6 to 96.7 with an average value of 23.5 for outdoor dust. The Σ20 OCP concentrations in these media were in the order: soil > outdoor dust > indoor dust, which was in contrast with the order of the detection frequency, i.e., indoor dust (95 to 100 %) > soil (60 to 90 %) > outdoor dust (30 to 80 %). The concentrations of the different OCP classes in these media followed the order: aldrin + dieldrin + endrin and its isomers (Drins) > chlordanes > dichlorodiphenyltrichloroethane (DDTs) > hexachlorocyclohexane (HCHs) > endosulfans for outdoor dust and soil, while that of the indoor dust followed the order: Drins > chlordanes > endosulfans > DDTs > HCHs. The cancer risk values for human exposure to OCPs in these sites exceeded 10-6 which indicates possible carcinogenic risks. The sources of OCPs in these media reflected both past use and recent inputs.

Associations of incident female breast cancer with long-term exposure to PM2.5 and its constituents: Findings from a prospective cohort study in Beijing, China.

This study aimed to investigate the association between long-term exposure to fine particulate matter (PM2.5) and its constituents (black carbon (BC), ammonium (NH4+), nitrate (NO3-), organic matter (OM), inorganic sulfate (SO42-)) and incident female breast cancer in Beijing, China. Data from a prospective cohort comprising 85,504 women enrolled in the National Urban Cancer Screening Program in Beijing (2013-2019) and the Tracking Air Pollution in China dataset are used. Monthly exposures were aggregated to calculate 5-year average concentrations to indicate long-term exposure. Cox models and mixture exposure models (weighted quantile sum, quantile-based g-computation, and explanatory machine learning model) were employed to analyze the associations. Findings indicated increased levels of PM2.5 and its constituents were associated with higher breast cancer risk, with hazard ratios per 1-µg/m3 increase of 1.02 (95% confidence interval (CI): 1.01, 1.03), 1.39 (95% CI: 1.16, 1.65), 1.28 (95% CI: 1.12, 1.46), 1.15 (95% CI: 1.05, 1.24), 1.05 (95% CI: 1.02, 1.08), and 1.15 (95% CI: 1.07, 1.23) for PM2.5, BC, NH4+, NO3-, OM, and SO42-, respectively. Exposure-response curves demonstrated a monotonic risk increase without an evident threshold. Mixture exposure models highlighted BC and SO42- as key factors, underscoring the importance of reducing emissions of these pollutants.