Ten years of mixing cocktails: a review of combination effects of endocrine-disrupting chemicals

Identification of pesticide mixtures to which French agricultural workers and farm-owners are exposed: Results from the Agriculture and Cancer (AGRICAN) cohort study

Farmers, particularly in Europe, are exposed to multiple pesticides during their working life. Such exposures can cause adverse health outcomes. We aimed to identify the main pesticide mixtures to which French agricultural workers are exposed and to classify farmers into clusters based on their mixture exposure profile. The AGRICAN cohort includes farm-owners and farm workers enrolled from 2005 to 2007, with information on exact years of beginning and end of pesticide use on 11 crops and five livestock. We estimated duration of exposure to 390 pesticides identified with the PESTIMAT crop-exposure matrix for 16,905 male pesticide users from 1950 to 2009. We used a Sparse Non-negative Matrix Under-approximation to identify the main pesticide mixtures based on exposure duration, and then applied hierarchical agglomerative clustering to classify farmers sharing similar profiles of co-exposure to the mixtures. SNMU suggested 6 optimal numbers of mixtures (4, 7, 11, 15, 27, 38) explaining from 29 to 91 % of total variance. We selected 27 mixtures. Mixtures contained between four to 22 pesticides and mostly concerned the use of pesticides on wheat/barley, vineyards, corn, fruit and vegetables or on multiple crops together. We selected 11 clusters composed of 395 to 4521 farmers. Some had a higher proportion of individuals working on specific crops (as vineyard or corn), while others were characterized by the diversity of crops (cluster 8:"Permanent crops, potatoes and tobacco"). This is the first study to identify pesticide mixtures in farmers and to classify them into clusters based on their mixture exposure profiles. The next step will be to study the associations between pesticide mixtures and health outcomes such as prostate cancer in AGRICAN.

Main factors influencing the perceived health risk of endocrine-disrupting chemicals: A systematic literature review

Endocrine-disrupting chemicals (EDCs) are linked to rising health issues such as infertility, childhood obesity, and asthma. While some research exists on health risk perceptions of EDCs, a comprehensive understanding across different populations and contexts is needed. We performed a systematic literature review, examining 45 articles published between 1985 and 2023, focusing on both the risk perception of EDCs as a whole as well as individual EDCs found in the environment (e.g., pesticides, bisphenol A, and phthalates). We identified four major categories of factors influencing EDC risk perception: sociodemographic factors (with age, gender, race, and education as significant determinants), family-related factors (highlighting increased concerns in households with children), cognitive factors (indicating that increased EDC knowledge generally led to increased risk perception), and psychosocial factors (with trust in institutions, worldviews, and health-related concerns as primary determinants). This review highlights the complex nature of EDC risk perception, shaped by sociodemographic, family, cognitive, and psychosocial factors, essential for policymakers in crafting educational and communication strategies. Future research should expand to cover more EDCs, use representative samples, and explore the influence of psychosocial factors on risk perception more deeply.

Associations of maternal and paternal preconception and maternal pregnancy urinary phthalate biomarker and bisphenol A concentrations with offspring autistic behaviors: The PEACE study

BACKGROUND

Environmental chemical exposures in utero may play a role in autism development. While preconception risk factors for autism are increasingly being investigated, little is known about the influence of chemical exposures during the preconception period, particularly for paternal exposures.

METHODS

In 195 children from the Preconception Environmental exposures And Childhood health Effects (PEACE) cohort born to parents recruited from a fertility clinic in Boston, Massachusetts between 2004 and 2017, we quantified concentrations of 11 phthalate metabolites and bisphenol A (BPA) in urine samples collected from mothers and fathers before conception and mothers throughout pregnancy. When children were 6-15 years old, parents completed the Social Responsiveness Scale (SRS) questionnaire assessing autistic behaviors. We used linear mixed effect models to estimate covariate-adjusted associations of phthalate biomarker and BPA concentrations, separately for maternal preconception (n = 179), paternal preconception (n = 121), and maternal pregnancy (n = 177), with SRS T-scores, based on age and gender, in offspring. We used quantile g-computation models for mixture analyses and evaluated modification by selected dietary factors.

RESULTS

The mean SRS T-score was 47.7 (±7.4), lower than the normative mean of 50. In adjusted models for individual biomarkers or mixtures, few associations were observed and estimates were generally negative (e.g., lower SRS T-scores) and imprecise. We observed associations of higher mono-isobutyl phthalate (MiBP) concentrations measured in maternal preconception and paternal preconception periods with lower SRS T-scores (βmaternal_precon = -1.6, 95% CI -2.7; -0.4; βpaternal_precon = -2.9, 95% CI -4.6; -1.2) for each loge increase. In a subset of participants with maternal preconception nutrition information, we generally observed stronger inverse associations with higher folate and iron intake, particularly for folate intake and MiBP concentrations.

CONCLUSIONS

Urinary phthalate biomarker and BPA concentrations during preconception (maternal and paternal) and pregnancy (maternal) were not associated with adverse autistic behaviors in these children. Larger studies are needed to elucidate the observed associations, while considering interactions between maternal nutrition and chemical exposures.

Effect of co-exposure to multiple metals (Pb, Cd, Cr, Hg, Fe, Mn and Ni) and metalloid (As) on liver function in Swiss albino mice

The study examined the cumulative toxic effect of multiple elements, As, Pb, Cd, Cr, Hg, Fe, Mn and Ni on the liver function and their association with inflammation and apoptosis. To explore the health consequence of simultaneous exposure to multiple metals and metalloid, male and female Swiss Albino mice were randomly divided into 14 groups and subjected to different doses [MPL (maximum permissible limit), 1×, 5×, 10×, 50× or 100×] of metal(loid)s mixture via drinking water for 8 weeks. Data showed that combined effect of multiple elements impaired the liver function. This was associated with significant decrease in the antioxidant enzymes and the elevation in lipid peroxidation for high exposure dose of 50× and 100× (p < 0.05). The metal(loid)s mixture exposure led to significant increase (p < 0.05) in cytokines, TNF-α, IL-6 and effector caspases (3 and 6) in exposure groups above 10× dose. Histopathological observation also revealed significant damage in the hepatic tissue on exposure to high dose. Dose dependent accumulation of respective elements (As, Cd, Cr, and Pb) in the liver was observed in each of the exposure groups. However, similar dose related increment was not observed for essential metals such as Ni, Fe and Mn. Differential accumulation of metals in the liver may be attributed to the effect of co-contaminant exposure, which could affect the divalent cation absorption due to antagonism and competitive transport process. Overall findings in this study manifest the complexity of possible joint effect of co-exposure to multiple metals and metalloid on the liver function.

Personalized mixture toxicity testing: A proof-of-principle in vitro study evaluating the steroidogenic effects of reconstructed contaminant mixtures measured in blood of individual adults

Chemical risk assessments typically focus on single substances, often overlooking real-world co-exposures to chemical mixtures. Mixture toxicology studies using representative mixtures can reveal potential chemical interactions, but these do not account for the unique chemical profiles that occur in the blood of diverse individuals. Here we used the H295R steroidogenesis assay to screen personalized mixtures of 24 persistent organic pollutants (POPs) for cytotoxicity and endocrine disruption. Each mixture was reconstructed at a human exposure relevant concentration (1×), as well as at 10- and 100-fold higher concentration (10×, 100×) by acoustic liquid handling based on measured blood concentrations in a Swedish cohort. Among the twelve mixtures tested, nine mixtures decreased the cell viability by 4-18%, primarily at the highest concentration. While the median and maximum mixtures based on the whole study population induced no measurable effects on steroidogenesis at any concentration, the personalized mixture from an individual with the lowest total POPs concentration was the only mixture that affected estradiol synthesis (35% increase at the 100× concentration). Mixtures reconstructed from blood levels of three different individuals stimulated testosterone synthesis at the 1× (11-15%) and 10× concentrations (12-16%), but not at the 100× concentration. This proof-of-principle personalized toxicity study illustrates that population-based representative chemical mixtures may not adequately account for the toxicological risks posed to individuals. It highlights the importance of testing a range of real-world mixtures at relevant concentrations to explore potential interactions and non-monotonic effects. Further toxicological studies of personalized contaminant mixtures could improve chemical risk assessment and advance the understanding of human health, as chemical exposome data become increasingly available.

Impact of organic foods on chronic diseases and health perception: a systematic review of the evidence

The aim of the present systematic review was to evaluate the existing data on the health impacts, of the consumption of organically grown foods versus conventionally farmed alternatives, with specific focus on the postulated health superiority of organic foods. A systematic literature research was performed in PubMed, Embase, Web of Science, and Google Scholar. Inclusion criteria were articles on adults (>18 years of age) consuming organic foods for ≥6 months, written in English language, and provision of comparative results between conventional and organic nutrition regarding health indices. From 1760 identified references, 21 primary research articles (2006-2022) met the inclusion criteria. Outcomes related to chronic disease prevalence, biomarker effects, and exposure to pesticides and other harmful substances were evaluated. A significant inverse relationship between organic food consumption and cardiometabolic risk factors, including obesity, diabetes mellitus, hypertension, and hyperlipidemia, was observed in the majority of prospective studies. The data on cancer risk and nutrient value comparison between organic and conventional foods were inconclusive. Clinical trials consistently indicated lower pesticide exposure in participants on organic diets, suggesting potential health benefits. The consumption of organic foods is associated with reduced cardiometabolic risks and pesticide exposure. However, the long-term impact on cancer risk remains undetermined. Future long-term studies are needed to establish whether an organic diet is superior to a conventional one in terms of overall health benefits.

Reduced bioenergetics and mitochondrial fragmentation in human primary cytotrophoblasts induced by an EGFR-targeting chemical mixture

Exposures to complex environmental chemical mixtures during pregnancy reach and target the feto-placental unit. This study investigates the influence of environmental chemical mixtures on placental bioenergetics. Recognizing the essential role of the epidermal growth factor receptor (EGFR) in placental development and its role in stimulating glycolysis and mitochondrial respiration in trophoblast cells, we explored the effects of chemicals known to disrupt EGFR signaling on cellular energy production. Human primary cytotrophoblasts (hCTBs) and a first-trimester extravillous trophoblast cell line (HTR-8/SVneo) were exposed to a mixture of EGFR-interfering chemicals, including atrazine, bisphenol S, niclosamide, PCB-126, PCB-153, and trans-nonachlor. An RNA sequencing approach revealed that the mixture altered the transcriptional signature of genes involved in cellular energetics. Next, the impact of the mixture on cellular bioenergetics was evaluated using a combination of mitochondrial and glycolytic stress tests, ATP production, glucose consumption, lactate synthesis, and super-resolution imaging. The chemical mixture did not alter basal oxygen consumption but diminished the maximum respiratory capacity in a dose-dependent manner, indicating a disruption of mitochondrial function. The respiratory capacity and ATP production were increased by EGF, while the Chem-Mix reduced both EGF- and non-EGF-mediated oxygen consumption rate in hCTBs. A similar pattern was observed in the glycolytic medium acidification, with EGF increasing the acidification, and the Chem-Mix blocking EGF-induced glycolytic acidification. Furthermore, direct stochastic optical reconstruction microscopy (dSTORM) imaging demonstrated that the Chem-Mix led to a reduction of the mitochondrial network architecture, with findings supported by a decrease in the abundance of OPA1, a mitochondrial membrane GTPase involved in mitochondrial fusion. In conclusion, we demonstrated that a mixture of EGFR-disrupting chemicals alters mitochondrial remodeling, resulting in disturbed cellular bioenergetics, reducing the capacity of human cytotrophoblast cells to generate energy. Future studies should investigate the mechanism by which mitochondrial dynamics are disrupted and the pathological significance of these findings.

The silent threat and countermeasures: Navigating the mixture risk of endocrine-disrupting chemicals on pregnancy loss in China

Currently, many countries and regions worldwide face the challenge of declining population growth due to persistently low rates of female reproduction. Since 2017, China's birth rate has hit historic lows and continued to decline, with the death rate now equaling the birth rate. Concerns have emerged regarding the potential impact of environmental contaminants on reproductive health, including pregnancy loss. Endocrine-disrupting chemicals (EDCs) like phthalate esters (PAEs), bisphenol A (BPA), triclosan (TCS), and perfluoroalkyl substances (PFASs) have raised attention due to their adverse effects on biological systems. While China's 14th Five-Year Plan (2021-2025) for national economic and social development included the treatment of emerging pollutants, including EDCs, there are currently no national appraisal standards or regulatory frameworks for EDCs and their mixtures. Addressing the risk of EDC mixtures is an urgent matter that needs consideration from China's perspective in the near future. In this Perspective, we delve into the link between EDC mixture exposure and pregnancy loss in China. Our focus areas include establishing a comprehensive national plan targeting reproductive-aged women across diverse urban and rural areas, understanding common EDC combinations in women and their surrounding environment, exploring the relationship between EDCs and pregnancy loss via epidemiology, and reconsidering the safety of EDCs, particularly in mixtures and low-dose scenarios. We envision that this study could aid in creating preventive strategies and interventions to alleviate potential risks induced by EDC exposure during pregnancy in China.

Opportunities offered by latent-based multiblock strategies to integrate biomarkers of chemical exposure and biomarkers of effect in environmental health studies

Modern environmental epidemiology benefits from a new generation of technologies that enable comprehensive profiling of biomarkers, including environmental chemical exposure and omic datasets. The integration and analysis of large and structured datasets to identify functional associations is constrained by computational challenges that cannot be overcome using conventional regression methods. Some extensions of Partial Least Squares (PLS) regression have been developed to efficently integrate multiple datasets, including Multiblock PLS (MB-PLS) and Sequential and Orthogonalized PLS; however, these approaches remain seldom applied in environmental epidemiology. To address that research gap, this study aimed to assess and compare the applicability of PLS-based multiblock models in an observational case study, where biomarkers of exposure to environmental chemicals and endogenous biomarkers of effect were simultaneously integrated to highlight biological links related to a health outcome. The methods were compared with and without sparsity coupling two metrics to support the variable selection: Variable Importance in Projection (VIP) and Selectivity Ratio (SR). The framework was applied to a case-study dataset mimicking the structure of 36 environmental exposure biomarkers (E-block), 61 inflammation biomarkers (M-block), and their relationships with the gestational age at delivery of 161 mother-infant pairs. The results showed an overall consistency in the selected variables across models, although some specific selection patterns were identified. The block-scaled concatenation-based approaches (e.g. MB-PLS) tended to select more variables from the E-block, while these methods were unable to identify certain variables in the M-block. Overall, the number of variables selected using the SR criterion was higher than using the VIP criterion, with lower predictive performances. The multiblock models coupled to VIP, appeared to be the methods of choice for identifying relevant variables with similar statistical performances. Overall, the use of multiblock PLS-based methods appears to be a good strategy to efficiently support the variable selection process in modern environmental epidemiology.

Identifying the most critical behavioral lifestyles associated with MAFLD: evidence from the NHANES 2017-2020

Background & aims

Accumulating studies have demonstrated associations between single lifestyle exposures and metabolic dysfunction-associated fatty liver disease (MAFLD). However, the joint effects of lifestyle exposures remain unclear, hindering the development of targeted prevention and control strategies. We aimed to investigate the joint associations between lifestyle exposomes and MAFLD.

Methods

This study included 5,002 participants from NHANES 2017-2020. Lifestyle exposomes, including sleep duration, metabolic equivalent of task (MET), Healthy Eating Index (HEI)-2015 score, alcohol consumption, and smoke exposure, were identified from questionnaire data. MAFLD was diagnosed by vibration-controlled transient elastography measurements and laboratory data. A logistic regression model and the weighted quantile sum method were used to evaluate the associations of single and joint lifestyle exposomes, respectively, with MAFLD. The population attributable fractions (PAFs) were calculated to assess the population benefits of different intervention strategies.

Results

Per-quartile range increases in sleep duration (OR=0.883, 95% CI: 0.826-0.944), MET (0.916, 0.871-0.963), and HEI-2015 score (0.827, 0.756-0.904) were significantly associated with MAFLD. The joint exposure of sleep duration, MET, and HEI-2015 score was associated with MAFLD (0.772, 0.688-0.865), with the highest weight (importance) for MET (0.526). PAFs revealed greater intervention benefits for sleep and the HEI-2015 when the majority of the population (>5%) had a low MAFLD risk (weak intervention targets), whereas MET was the most efficient intervention strategy when minority populations (≤5%) had a low MAFLD risk (strong intervention targets).

Conclusion

This study demonstrated significant associations between MAFLD and single and joint exposures to sleep duration, MET, and HEI-2015 and identified physical activity as the most important lifestyle factor. Further population benefit analyses may provide evidence and suggestions for population-level interventions.

Thresholds of adversity for endocrine disrupting substances: a conceptual case study

For endocrine disrupting chemicals (EDC) the existence of "safe exposure levels", that is exposure levels that do not present an appreciable risk to human health is most controversially discussed, as is the existence of health-based reference values. Concerns have been especially raised that EDCs might not possess a threshold level such that no exposure level to EDCs can be considered safe. To explore whether or not threshold levels can be identified, we performed a screening exercise on 14 pesticidal and biocidal active substances previously identified as EDCs in the European Union. The respective substances are ideal subjects for case studies to review for endocrine activity and disruptive potential following well-defined regulatory assessment based on solid data to effectually establish adversity as consequence of endocrine disruption. Dimethomorph, metiram and propiconazole for which the weight of evidence demonstrating endocrine disruption was the strongest were used as subjects for further study. Epoxiconazole was additionally selected as its effects on the endocrine system are extensive. For all four substances, analysis of the toxicological data clearly indicated thresholds of adversity below which no adverse effects mediated through an endocrine mechanism were observed. Particular emphasis was placed on mechanistic considerations including homeostasis and the concept of adversity. As a proof of concept this study provides evidence that like other substances of toxicological concern EDCs have threshold levels for adversity. While for some EDCs the respective thresholds might indeed be very low this shows that, data allowing, for other EDCs sufficiently protective reference values can be derived.

Prenatal exposure to multiple environmental chemicals and birth size

BACKGROUND

Epidemiological studies addressing the combined effects of exposure to chemical mixtures at different stages of pregnancy on birth size are scarce.

OBJECTIVE

To evaluate the association between prenatal exposure to chemical mixtures and birth size.

METHODS

Our previous study repeatedly measured the urinary concentrations of 34 chemical substances among 743 pregnant women and identified three distinct clusters of exposed population and six dominant principal components of exposed chemicals in each trimester. In this study, we assessed the associations of these exposure profiles with birth weight, birth length, and ponderal index using multivariable linear regression.

RESULTS

We found that compared with women in cluster 1 (lower urinary chemical concentrations), women in cluster 2 (higher urinary concentrations of metals, benzothiazole, benzotriazole, and some phenols), and women in cluster 3 (higher urinary concentrations of phthalates) were more likely to give birth to children with higher birth length [0.23 cm (95% CI: -0.03, 0.49); 0.29 cm (95%CI: 0.03, 0.54), respectively]. This association was observed only in 1st trimester. In addition, prenatal exposure to PC3 (higher benzophenones loading) was associated with reduced birth length across pregnancy [-0.07 cm (95% CI: -0.18, 0.03) in 1st and 2nd trimester; -0.13 cm (95% CI: -0.24, -0.03) in 3rd trimester]. Exposure to PC6 (higher thallium and BPA loading in 2nd trimester) was associated with increased birth length [0.15 cm (95% CI: 0.05, 0.26)]. Compared with other outcomes, associations of both clusters and PCs with birth length were stronger, and these associations were more pronounced in boys.

IMPACT STATEMENT

Exposure to multiple chemicals simultaneously, the actual exposure situation of pregnant women, was associated with birth size, indicating that chemical mixtures should be taken more seriously when studying the health effects of pollutants.

The exposure to UV filters: Prevalence, effects, possible molecular mechanisms of action and interactions within mixtures

Substances that can absorb sunlight and harmful UV radiation such as organic UV filters are widely used in cosmetics and other personal care products. Since humans use a wide variety of chemicals for multiple purposes it is common for UV filters to co-occur with other substances either in human originating specimens or in the environment. There is increasing interest in understanding such co-occurrence in form of potential synergy, antagonist, or additive effects of biological systems. This review focuses on the collection of data about the simultaneous occurrence of UV filters oxybenzone (OXYB), ethylexyl-methoxycinnamate (EMC) and 4-methylbenzylidene camphor (4-MBC) as well as other classes of chemicals (such as pesticides, bisphenols, and parabens) to understand better any such interactions considering synergy, additive effect and antagonism. Our analysis identified >20 different confirmed synergies in 11 papers involving 16 compounds. We also highlight pathways (such as transcriptional activation of estrogen receptor, promotion of estradiol synthesis, hypothalamic-pituitary-gonadal (HPG) axis, and upregulation of thyroid-hormone synthesis) and proteins (such as Membrane Associated Progesterone Receptor (MAPR), cytochrome P450, and heat shock protein 70 (Hsp70)) that can act as important key nodes for such potential interactions. This article aims to provide insight into the molecular mechanisms on how commonly used UV filters act and may interact with other chemicals.

Exposure to UV-B filter octylmethoxycinnamate and human health effects: Focus on endocrine disruptor actions

Human skin is the first line of photoprotection against UV radiation. However, despite having its defence mechanisms, the photoprotection that the skin exerts is not enough. To protect human skin, the inclusion of UV filters in the cosmetic industry has grown significantly as a photoprotection strategy. Octylmethoxycinnamate, also designated by octinoxate, or 2-ethylhexyl-4-methoxycinnamate (CAS number: 5466-77-3) is one of the most widely used UV-B filter in the cosmetic industry. The toxic effects of OMC have alarmed the public, but there is still no consensus in the scientific community about its use. This article aims to provide an overview of the UV filters' photoprotection, emphasizing the OMC and the possible negative effects it may have on the public health. Moreover, the current legislation will be addressed. In summary, the recommendations should be rethought to assess their risk-benefit, since the existing literature warns us to endocrine-disrupting effects of OMC. Further studies should be focus on the toxicity of OMC alone, in mixture and should consider its degradation products, to improve the knowledge of its risk assessment as EDC.

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.

A review of common statistical methods for dealing with multiple pollutant mixtures and multiple exposures

Traditional environmental epidemiology has consistently focused on studying the impact of single exposures on specific health outcomes, considering concurrent exposures as variables to be controlled. However, with the continuous changes in environment, humans are increasingly facing more complex exposures to multi-pollutant mixtures. In this context, accurately assessing the impact of multi-pollutant mixtures on health has become a central concern in current environmental research. Simultaneously, the continuous development and optimization of statistical methods offer robust support for handling large datasets, strengthening the capability to conduct in-depth research on the effects of multiple exposures on health. In order to examine complicated exposure mixtures, we introduce commonly used statistical methods and their developments, such as weighted quantile sum, bayesian kernel machine regression, toxic equivalency analysis, and others. Delineating their applications, advantages, weaknesses, and interpretability of results. It also provides guidance for researchers involved in studying multi-pollutant mixtures, aiding them in selecting appropriate statistical methods and utilizing R software for more accurate and comprehensive assessments of the impact of multi-pollutant mixtures on human health.

The Effects of Wastewater Reuse on Smallmouth Bass (Micropterus dolomieu) Relative Abundance in the Shenandoah River Watershed, USA

Municipal and industrial wastewater effluent is an important source of water for lotic systems, especially during periods of low flow. The accumulated wastewater effluent flows-expressed as a percentage of total streamflow (ACCWW%)-contain chemical mixtures that pose a risk to aquatic life; fish may be particularly vulnerable when chronically exposed. Although there has been considerable focus on individual-level effects of exposure to chemical mixtures found in wastewater effluent, scaling up to population-level effects remains a challenging component needed to better understand the potential consequences of exposure in wild populations. This may be particularly important under a changing climate in which wastewater reuse could be essential to maintain river flows. We evaluated the effects of chronic exposure to wastewater effluent, as measured by ACCWW%, on the relative abundance of young-of-year (YOY), juvenile, and adult smallmouth bass (Micropterus dolomieu) populations in the Shenandoah River Watershed (USA). We found that increases in ACCWW% in the previous year and during the prespawn period were negatively correlated with the relative abundance of YOY, resulting in an average 41% predicted decrease in abundance (range = 0.5%-94% predicted decrease in abundance). This lagged effect suggests that adult fish reproductive performance may be compromised by chemical exposure during periods of high ACCWW%. No relationships between ACCWW% and juvenile or adult relative abundance were found, suggesting that negative effects of ACCWW% on YOY abundance may be offset due to compensatory mechanisms following higher ACCWW% exposure. Understanding the effects of wastewater effluent exposure at multiple levels of biological organization will help in the development of management strategies aimed at protecting aquatic life. Environ Toxicol Chem 2024;00:1-11. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Selenium and zinc supplementation mitigates metals-(loids) mixture- mediated cardiopulmonary toxicity via attenuation of antioxidant, anti-inflammatory and antiapoptotic mechanisms in female Sprague Dawley rats

This study evaluated the cardiopulmonary protective effects of essential elements (Zn and Se) against heavy metals mixture (HMM) exposure. Twenty five female Sprague Dawley albino rats, divided in to five groups: controls were orally treated only with distilled water; next, group 2 was exposed to HMM with the following concentrations: 20 mg/kg of Pb body weight, 0.40 mg/kg of Hg, 0.56 mg/kg of Mn, and 35 mg/kg of Al. Groups 3, 4 and 5 were exposed to HMM and co-treated with zinc chloride (ZnCl2; 0.80 mg/kg), sodium selenite (Na2SeO3;1.50 mg/kg) and both zinc chloride and sodium selenite, respectively. The experiment lasted for 60 days. Afterwards animals were sacrificed, and we conduced biochemical and histopathological examination of the heart and lungs. HMM only exposed animals had an increased levels of malondialdehyde (MDA) and nitric oxide (NO), increased IL-6 and TNF-α, attenuated SOD, GPx, CAT and GSH and caspase 3 in the heart and lungs. HMM affected NF-kB and Nrf2 in the heart muscle with histomorphological alterations. Zn and Se attenuated adverse effects of HMM exposure. Essential element supplementation ameliorated heavy metal cardiopulmonary intoxication in rats.

Associations of personal care products use with reproductive outcomes of IVF/ICSI treatment

Introduction

Personal care products (PCPs) contain a number of endocrine-disrupting chemicals (EDCs) that could potentially affect the reproductive function in women of childbearing age. However, studies focused on the effects of PCPs use on reproductive outcomes are very limited. The current study aimed to explore the relationships between PCPs use patterns and reproductive outcomes in women undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment.

Methods

A total of 1500 women from the Tongji Reproductive and Environmental (TREE) study between December 2018 and January 2020 were included in this study. Participants provided characteristics of PCPs use within the previous three months. Retrieved oocyte number, mature oocyte number, two distinct pronuclei (2PN) zygote number, fertilization rate, cleavage rate, blastocyst formation rate, implantation, clinical pregnancy, miscarriage, and live birth were followed up as reproductive endpoints. Generalized linear regression model was utilized to assess the associations between various categories of PCPs use and reproductive endpoints of IVF/ICSI.

Results

After adjusting for relevant covariates, women who used skin care products ≥14 times per week had a reduction of 22.4% in the maturation rate (95% CI: -39.2%, -1.6%) compared to participants who did not use skin care products. After transferring fresh embryos, women who used cosmetics 1-2 times per week (adjusted OR = 2.2, 95% CI: 1.0, 4.8) or 3-7 times per week (adjusted OR = 2.5, 95% CI: 1.2, 5.2) had a higher possibility of miscarriage than those who did not use cosmetics. There was negative association between the use of gel or soap and the cleavage rate among women aged < 30 years old (P for interaction = 0.01). Among women with BMI ≥ 24 kg/m2, the use of gel or soap was negatively associated with the blastocyst formation rate (P for interaction = 0.04), while cosmetics use was negatively associated with the maturation rate (P for interaction = 0.001).

Conclusion

Our findings suggest that the use of PCPs in women of reproductive age have a potential adverse impact on IVF/ICSI outcomes, particularly skin care and cosmetic products.

Bisphenol A and chlorinated derivatives of bisphenol A assessment in end stage renal disease patients: Impact of dialysis therapy

Patients with end stage kidney disease treated by dialysis (ESKDD) process dialysis sessions to remove molecules usually excreted by kidneys. However, dialysis therapy could also contribute to endocrine disruptors (ED) burden. Indeed, materials like dialyzer filters, ultrapure dialysate and replacement fluid could exposed ESKDD patients to Bisphenol A (BPA) and chlorinated derivatives of BPA (ClxBPAs). Thus, our aim was to compare BPA and ClxBPAs exposure between ESKDD patients, patients with stage 5 chronic kidney disease (CKD5) not dialyzed and healthy volunteers. Then we describe the impact of a single dialysis session, according to dialysis modalities (hemodialysis therapy (HD) versus online hemodiafiltration therapy (HDF)) and materials used with pre-post BPA and ClxBPAs concentrations. The plasma levels of BPA and four ClxBPAs, were assessed for 64 ESKDD patients in pre and post dialysis samples (32 treated by HD and 32 treated by HDF) in 36 CKD5 patients and in 24 healthy volunteers. BPA plasma concentrations were 22.5 times higher for ESKDD patients in pre-dialysis samples versus healthy volunteers (2.208 ± 5.525 ng/mL versus 0.098 ± 0.169 ng/mL) (p < 0.001). BPA plasma concentrations were 16 times higher for CKD5 patients versus healthy volunteers, but it was not significant (1.606 ± 3.230 ng/mL versus 0.098 ± 0.169 ng/mL) (p > 0.05). BPA plasma concentrations for ESKDD patients in pre-dialysis samples were 1.4 times higher versus CKD5 patients (2.208 ± 5.525 ng/mL versus 1.606 ± 3.230 ng/mL) (p < 0.001). For healthy volunteers, ClxBPAs were never detected, or quantified while for CKD5 and ESKDD patients one ClxBPAs at least has been detected or quantified in 14 patients (38.8%) and 24 patients (37.5%), respectively. Dialysis therapy was inefficient to remove BPA either for HD (1.983 ± 6.042 ng/mL in pre-dialysis versus 3.675 ± 8.445 ng/mL in post-dialysis) or HDF (2.434 ± 5.042 ng/mL in pre-dialysis versus 7.462 ± 15.960 ng/mL in post dialysis) regarding pre-post BPA concentrations (p > 0.05). The same result was observed regarding ClxBPA analysis. Presence of polysulfone in dialyzer fibers overexposed ESKDD patients to BPA in pre-dialysis samples with 3.054 ± 6.770 for ESKDD patients treated with a polysulfone dialyzer versus 0.708 ± 0.638 (p = 0.040) for ESKDD patients treated without a polysulfone dialyzer and to BPA in post-dialysis samples with 6.629 ± 13.932 for ESKDD patients treated with a polysulfone dialyzer versus 3.982 ± 11.004 (p = 0.018) for ESKDD patients treated without a polysulfone dialyzer. This work is to our knowledge the first to investigate, the impact of a dialysis session and materials used on BPA and ClxBPAs plasma concentrations and to compare these concentrations to those found in CKD5 patients and in healthy volunteers.

Comprehensive assessment of the estrogenic activity of resin composites

Resin-based dental composites have been developed to restore decayed teeth or modify tooth color due to their excellent physical and chemical properties. Such composites may have intrinsic toxicity due to components released into the mouth during the early stage of polymerization, and afterward as a result of erosion or material decomposition. In addition, resin-based dental composites have potential environmental pollutant by elution of monomers and degradation. Since certain monomers of resin matrices are synthesized from bisphenol A (BPA), which acts as an estrogenic endocrine disruptor, these resin matrices may have estrogenic activity. Therefore, the estrogenic endocrine-disrupting activity of various dental composites should be evaluated. In this study, we evaluated the estrogenic endocrine-disrupting activity of 10 resin composites by using a BRET-based estrogen receptor (ER)α and ERβ dimerization assays and ER transactivation assay. BPA, BisDMA, BisGMA, BisEMA, TEGDMA, HMBP, and DMPA mediated ERα dimerization, and BPA, BisDMA, and DMPA also mediated ERβ dimerization. Except for UDMA and CQ, all the compounds were identified as estrogen agonists or antagonists. In-depth information for the safe use of dental composites was acquired, and it was confirmed how the component of dental composites acts in the ER signaling pathway. Further studies on the low-dose and long-term release of these compounds are needed to ensure the safe use of these resin-based dental composites.

Multi-omic responses of fish exposed to complex chemical mixtures in the Shenandoah River watershed

To evaluate relationships between different anthropogenic impacts, contaminant occurrence, and fish health, we conducted in situ fish exposures across the Shenandoah River watershed at five sites with different land use. Exposure water was analyzed for over 500 chemical constituents, and organismal, metabolomic, and transcriptomic endpoints were measured in fathead minnows. Adverse reproductive outcomes were observed in fish exposed in the upper watershed at both wastewater treatment plant (WWTP) effluent- and agriculture-impacted sites, including decreased gonadosomatic index and altered secondary sex characteristics. This was accompanied with increased mortality at the site most impacted by agricultural activities. Molecular biomarkers of estrogen exposure were unchanged and consistent with low or non-detectable concentrations of common estrogens, indicating that alternative mechanisms were involved in organismal adverse outcomes. Hepatic metabolomic and transcriptomic profiles were altered in a site-specific manner, consistent with variation in land use and contaminant profiles. Integrated biomarker response data were useful for evaluating mechanistic linkages between contaminants and adverse outcomes, suggesting that reproductive endocrine disruption, altered lipid processes, and immunosuppression may have been involved in these organismal impacts. This study demonstrated linkages between human-impact, contaminant occurrence, and exposure effects in the Shenandoah River watershed and showed increased risk of adverse outcomes in fathead minnows exposed to complex mixtures at sites impacted by municipal wastewater discharges and agricultural practices.

Shotgun Proteomic-Based Approach with a Q-Exactive Hybrid Quadrupole-Orbitrap High-Resolution Mass Spectrometer for Protein Adductomics on a 3D Human Brain Tumor Neurospheroid Culture Model: The Identification of Adduct Formation in Calmodulin-Dependent Protein Kinase-2 and Annexin-A1 Induced by Pesticide Mixture

Pesticides are increasingly used in combinations in crop protection, resulting in enhanced toxicities for various organisms. Although protein adductomics is challenging, it remains a powerful bioanalytical tool to check environmental exposure and characterize xenobiotic adducts as putative toxicity biomarkers with high accuracy, facilitated by recent advances in proteomic methodologies and a mass spectrometry high-throughput technique. The present study aims to predict the potential neurotoxicity effect of imidacloprid and λ-cyhalothrin insecticides on human neural cells. Our protocol consisted first of 3D in vitro developing neurospheroids derived from human brain tumors and then treatment by pesticide mixture. Furthermore, we adopted a bottom-up proteomic-based approach using nanoflow ultraperformance liquid chromatography coupled with a high-resolution mass spectrometer for protein-adduct analysis with prediction of altered sites. Two proteins were selected, namely, calcium-calmodulin-dependent protein kinase-II (CaMK2) and annexin-A1 (ANXA1), as key targets endowed with primordial roles. De novo sequencing revealed several adduct formations in the active site of 82-ANXA1 and 228-CaMK2 as a result of neurotoxicity, predicted by the added mass shifts for the structure of electrophilic precursors. To the best of our knowledge, our study is the first to adopt a proteomic-based approach to investigate in depth pesticide molecular interactions and their potential to adduct proteins which play a crucial role in the neurotoxicity mechanism.

A Critical Review on the Opportunity to Use Placenta and Innovative Biomonitoring Methods to Characterize the Prenatal Chemical Exposome

Adverse effects associated with chemical exposures during pregnancy include several developmental and reproductive disorders. However, considering the tens of thousands of chemicals present on the market, the effects of chemical mixtures on the developing fetus is still likely underestimated. In this critical review, we discuss the potential to apply innovative biomonitoring methods using high-resolution mass spectrometry (HRMS) on placenta to improve the monitoring of chemical exposure during pregnancy. The physiology of the placenta and its relevance as a matrix for monitoring chemical exposures and their effects on fetal health is first outlined. We then identify several key parameters that require further investigations before placenta can be used for large-scale monitoring in a robust manner. Most critical is the need for standardization of placental sampling. Placenta is a highly heterogeneous organ, and knowledge of the intraplacenta variability of chemical composition is required to ensure unbiased and robust interindividual comparisons. Other important variables include the time of collection, the sex of the fetus, and mode of delivery. Finally, we discuss the first applications of HRMS methods on the placenta to decipher the chemical exposome and describe how the use of placenta can complement biofluids collected on the mother or the fetus.

Risk assessment of the asthma-induction potential of substances in spray products for car cabin detailing - based on EU's Chemical Agents Directive, using harmonised classifications and quantitative structure-activity relationship (QSAR)

Exposure to spray-formulated products for car cabin detailing is a potential risk for asthma induction. With a focus on the asthma-related endpoints sensitisation and irritation of the lungs, we performed an occupational risk assessment based on requirements in the EU Chemical Agents Directive. We identified 71 such spray products available in Denmark. We identified ingredient substances in safety data sheets and screened for harmonised classifications of respiratory sensitisation and airway irritation. For respiratory sensitisation, we also applied quantitative structure-activity relationship (QSAR). We modelled the exposure during 15 min of work inside a car cabin, and determined the risk ratio of the products by further applying occupational exposure limits - mainly derived no-effect levels (DNELs) from the European Chemicals Agency (ECHA) set on respiratory irritation. Four substances had a harmonised classification for respiratory irritation (bronopol, 2-phenoxyethanol, 2-methoxypropanol, and butan-1-ol). Seven substances were positive in the QSAR model for respiratory sensitisation (monoethanolamine, bronopol, glycerol, methyl salicylate, benzoic acid, ammonium benzoate, and sodium benzoate). Two vinyl treatment products had a risk ratio > 1 based on the level of sodium benzoate and its DNEL set on respiratory irritation. Two products had risk ratios of 0.69 and 0.73, respectively, based on 2-methyl-2 H-isothiazol-3-one and its acute DNEL set on respiratory irritation. In conclusion, 10 substances that may pose a risk for asthma induction were identified in the products. Two of the 71 products had a risk ratio > 1, meaning they may pose an asthma-induction risk in the modelled exposure scenario and using respiratory irritation DNELs from ECHA.

Endocrine disruptors in dialysis therapies: A literature review

Endocrine disrupting chemicals (EDCs) were defined as "an exogenous substance or mixture that alters function(s) of the endocrine system and consequently causes adverse health effects". These compounds are mainly eliminated by the renal route. However, patients with end-stage kidney disease treated by dialysis (ESKDD) can no longer eliminate these EDCs efficiently. Furthermore, EDCs exposure could occur via leaching from medical devices used in dialysis therapy. As a result, ESKDD patients are overexposed to EDCs. The aims of this study were to summarize EDCs exposure of ESKDD patients and to evaluate the factors at the origin of this exposure. To handle these objectives, we performed a literature review. An electronic search on PubMed, Embase and Web of science databases was performed. Twenty-six studies were finally included. The EDCs reported in these studies were Bisphenol A (BPA), Bisphenol S (BPS), Bisphenol B (BPB), Nonylphenol, Di(2-ethylhexyl) phthalate (DEHP), Di-n-butyl phthalate (DBP), and Butylbenzyl phthalate (BBP). Regarding the environment of dialysis patients, BPA, BPB, BPS, DEHP, DBP and nonylphenol have been found. Environmental exposure affects EDCs blood levels in ESKDD patients who are overexposed to BPA, BPS, BPB and DEHP. For ESKDD patients, dialyzers with housing in polycarbonate and fibers in polysulfone seem to overexpose them to BPA. Regarding dialysis therapy, peritoneal dialysis seems to decrease patient exposure vs hemodialysis therapy, and hemodiafiltration therapy seems to reduce this exposure vs hemodialysis therapy. Regarding DEHP, levels tend to increase during dialysis and when DEHP plasticizer is used in PVC devices. Finally, in the European Union a regulation on medical devices was adopted on 5 April 2017 and has been applied recently. This regulation will regulate EDCs in medical devices and thereby contribute to reconsideration of their conceptions and, finally, to reduction of ESKDD patients' exposure.

Prenatal exposure to phthalates and gender-specific play behavior at seven years of age in the SELMA study

BACKGROUND

A growing body of evidence shows that prenatal exposure to phthalates affects child development. Since many phthalates have been shown to alter endocrine signaling, they may influence reproductive development, neurodevelopment, and child behavior. Indeed, a few studies reported associations between prenatal phthalate exposure and gender-specific play behavior. However, evidence for this relationship is limited, and previous findings are based on single phthalates, while human exposure entails mixtures of chemicals.

OBJECTIVE

We aimed to investigate the associations between prenatal exposure to single phthalates, as well as a phthalate mixture, and gender-specific play behavior.

METHODS

A total of 715 mother-child pairs from the Swedish Environmental Longitudinal, Mother and Child, Asthma and Allergy (SELMA) study were included. In the median week 10 of pregnancy, phthalate metabolites were measured in urine. Gender-specific play behavior was measured with Preschool Activities Inventory at the age of seven years. Linear and weighted quantile sum regressions were used; data was stratified by sex. Models were adjusted for child and maternal age, maternal education, parental attitudes toward play behavior, and urinary creatinine concentration.

RESULTS

For boys, single compound analyses revealed negative associations of prenatal exposure to di-isononyl phthalate (DINP) concentrations with masculine (β = -1.44; 95% CI = -2.72, -0.16) and composite (β = -1.43; 95% CI = -2.72, -0.13) scores. Suggestive associations were also observed with a mixture approach identifying DINP as the main contributor of the association of decreased masculine play. Among girls, higher urinary concentrations of 2,4-methyl-7-oxyooctyl-oxycarbonyl-cyclohexane carboxylic acid (MOiNCH) was associated with decreased feminine (β = -1.59; 95% CI = -2.62, -0.57) and masculine scores (β = -1.22; 95% CI = -2.14, -0.29), whereas the mixture analyses did not yield conclusive results for girls.

CONCLUSION

Our findings suggest associations of prenatal exposure to DINP with decreased masculine play behavior in boys while the results for girls were not fully conclusive.

Exposure to phenols, chlorophenol pesticides, phthalate and PAHs and mortality risk: A prospective study based on 6 rounds of NHANES

OBJECTIVES

Human exposure to various endocrine disrupting chemicals (EDCs) is widespread and long-lasting. The primary objective of this study was to prospectively evaluate the association of combined exposure of phenols, chlorophenol pesticides, phthalate and polycyclic aromatic hydrocarbons (PAHs) and mortality risk in a representative US population.

METHODS

The data on urinary levels of phenols, chlorophenol pesticides, phthalates, and PAH metabolites, were collected from participants aged ≥20 years in six rounds of the National Health and Nutrition Examination Survey (NHANES) (2003-2014). NHANES-linked death records up to December 31, 2015 were used to ascertain mortality status and cause of death. Cox proportional hazards and competing risk models were mainly used for chemical and mortality risk association analysis. The weighted quantile sum (WQS) regression and the least absolute shrinkage and selection operator regression were employed to estimate the association between EDC co-exposure and mortality risk.

RESULTS

High levels of mono-n-butyl phthalate, monobenzyl phthalate, and 1-napthol were significantly associated with increased risk of all cause, cardiovascular disease (CVD) and cancer mortality among all participants. WQS index was associated with the risks of all-cause (hazard ratio [HR] = 1.389, 95%CI: 1.155-1.669) and CVD mortality (HR = 1.925, 95%CI: 1.152-3.216). High co-exposure scores were associated with elevated all-cause (HR = 2.842, 95% CI: 1.2.094-3.858), CVD (HR = 1.855, 95% CI: 1.525-2.255), and cancer mortality risks (HR = 2.961, 95% CI: 1.468-5.972). The results of subgroup analysis, competing risk model, and sensitivity analysis were generally consistent with the findings from the main analyses, indicating the robustness of our findings.

CONCLUSIONS

This study provided the first epidemiological evidence that co-exposure to EDC at fairly low levels contributed to elevated mortality risk among US adults. The underlying mechanisms for the effects of EDC co-exposure on human health are worthy of future exploration.

Endocrine Health and Health Care Disparities in the Pediatric and Sexual and Gender Minority Populations: An Endocrine Society Scientific Statement

Endocrine care of pediatric and adult patients continues to be plagued by health and health care disparities that are perpetuated by the basic structures of our health systems and research modalities, as well as policies that impact access to care and social determinants of health. This scientific statement expands the Society's 2012 statement by focusing on endocrine disease disparities in the pediatric population and sexual and gender minority populations. These include pediatric and adult lesbian, gay, bisexual, transgender, queer, intersex, and asexual (LGBTQIA) persons. The writing group focused on highly prevalent conditions-growth disorders, puberty, metabolic bone disease, type 1 (T1D) and type 2 (T2D) diabetes mellitus, prediabetes, and obesity. Several important findings emerged. Compared with females and non-White children, non-Hispanic White males are more likely to come to medical attention for short stature. Racially and ethnically diverse populations and males are underrepresented in studies of pubertal development and attainment of peak bone mass, with current norms based on European populations. Like adults, racial and ethnic minority youth suffer a higher burden of disease from obesity, T1D and T2D, and have less access to diabetes treatment technologies and bariatric surgery. LGBTQIA youth and adults also face discrimination and multiple barriers to endocrine care due to pathologizing sexual orientation and gender identity, lack of culturally competent care providers, and policies. Multilevel interventions to address these disparities are required. Inclusion of racial, ethnic, and LGBTQIA populations in longitudinal life course studies is needed to assess growth, puberty, and attainment of peak bone mass. Growth and development charts may need to be adapted to non-European populations. In addition, extension of these studies will be required to understand the clinical and physiologic consequences of interventions to address abnormal development in these populations. Health policies should be recrafted to remove barriers in care for children with obesity and/or diabetes and for LGBTQIA children and adults to facilitate comprehensive access to care, therapeutics, and technological advances. Public health interventions encompassing collection of accurate demographic and social needs data, including the intersection of social determinants of health with health outcomes, and enactment of population health level interventions will be essential tools.

Toxicogenomic analysis of physiologically important metals: An integrated in silico approach

Biologically important metals regulate cellular homeostasis in living systems. Anthropogenic exposure to these metals can cause adverse effects, including an increased incidence of diseases in humans such as cancer, lung, and cardiovascular defects. However, the effects of metals and the common genes/signaling pathways involved in metal toxicity have not been elucidated. Hence, the present study used toxicogenomic data mining with the comparative toxicogenomics database to explore the impact of these metals. The metals were categorized into transition, alkali, and alkali earth. The common genes were identified and subjected to functional enrichment analysis. Further, gene-gene and protein-protein interactions were assessed. Also, the top ten transcription factors and miRNAs that regulate the genes were identified. The phenotypes and diseases that have increased incidence upon alterations of these genes were detected. Overall, we were able to identify IL1B and SOD2 as the common genes, along with the AGE-RAGE signaling pathway in diabetic complications as the common pathway altered. Enriched genes and pathways specific to each metal category were also found. Further, we identified heart failure as the major diseases that have increased the incidence of these metals' exposure. In conclusion, exposure to essential metals might cause adverse effects via inflammation and oxidative stress.

Toxicity dose descriptors from animal inhalation studies of 13 nanomaterials and their bulk and ionic counterparts and variation with primary particle characteristics

This study collects toxicity data from animal inhalation studies of some nanomaterials and their bulk and ionic counterparts. To allow potential grouping and interpretations, we retrieved the primary physicochemical and exposure data to the extent possible for each of the materials. Reviewed materials are compounds (mainly elements, oxides and salts) of carbon (carbon black, carbon nanotubes, and graphene), silver, cerium, cobalt, copper, iron, nickel, silicium (amorphous silica and quartz), titanium (titanium dioxide), and zinc (chemical symbols: Ag, C, Ce, Co, Cu, Fe, Ni, Si, Ti, TiO₂, and Zn). Collected endpoints are: a) pulmonary inflammation, measured as neutrophils in bronchoalveolar lavage (BAL) fluid at 0-24 hours after last exposure; and b) genotoxicity/carcinogenicity. We present the dose descriptors no-observed-adverse-effect concentrations (NOAECs) and lowest-observed-adverse-effect concentrations (LOAECs) for 88 nanomaterial investigations in data-library and graph formats. We also calculate 'the value where 25% of exposed animals develop tumors' (T25) for carcinogenicity studies. We describe how the data may be used for hazard assessment of the materials using carbon black as an example. The collected data also enable hazard comparison between different materials. An important observation for poorly soluble particles is that the NOAEC for neutrophil numbers in general lies around 1 to 2 mg/m³. We further discuss why some materials' dose descriptors deviate from this level, likely reflecting the effects of the ionic form and effects of the fiber-shape. Finally, we discuss that long-term studies, in general, provide the lowest dose descriptors, and dose descriptors are positively correlated with particle size for near-spherical materials.

Reproductive toxicity of combined effects of endocrine disruptors on human reproduction

Confluence of environmental, genetic, and lifestyle variables is responsible for deterioration of human fecundity. Endocrine disruptors or endocrine disrupting chemicals (EDCs) may be found in a variety of foods, water, air, beverages, and tobacco smoke. It has been demonstrated in experimental investigations that a wide range of endocrine disrupting chemicals have negative effects on human reproductive function. However, evidence on the reproductive consequences of human exposure to endocrine disrupting chemicals is sparse and/or conflicting in the scientific literature. The combined toxicological assessment is a practical method for assessing the hazards of cocktails of chemicals, co-existing in the environment. The current review provides a comprehensive overview of studies emphasizing the combined toxicity of endocrine disrupting chemicals on human reproduction. Endocrine disrupting chemicals interact with each other to disrupt the different endocrine axes, resulting in severe gonadal dysfunctions. Transgenerational epigenetic effects have also been induced in germ cells, mostly through DNA methylation and epimutations. Similarly, after acute or chronic exposure to endocrine disrupting chemicals combinations, increased oxidative stress (OS), elevated antioxidant enzymatic activity, disrupted reproductive cycle, and reduced steroidogenesis are often reported consequences. The article also discusses the concentration addition (CA) and independent action (IA) prediction models, which reveal the importance of various synergistic actions of endocrine disrupting chemicals mixtures. More crucially, this evidence-based study addresses the research limitations and information gaps, as well as particularly presents the future research views on combined endocrine disrupting chemicals toxicity on human reproduction.

Validation of an isotope dilution mass spectrometry (IDMS) measurement procedure for the reliable quantification of steroid hormones in waters

Reliable data are compulsory to efficiently monitor pollutants in aquatic environments, particularly steroid hormones that can exert harmful effects at challenging analytical levels below the ng L^-1. An isotope dilution two-step solid-phase extraction followed by an ultra-performance liquid chromatography separation coupled to tandem mass spectrometry (UPLC-MS/MS) detection method was validated for the quantification of 21 steroid hormones (androgens, estrogens, glucocorticoids, and progestogens) in whole waters. To achieve a realistic and robust assessment of the performances of this method, the validation procedure was conducted using several water samples representative of its intended application. These samples were characterized in terms of concentration of ionic constituents, suspended particulate matter (SPM), and dissolved organic carbon contents (DOC). For estrogens that are part of the European Water Framework Directive Watchlist (17beta-estradiol and estrone), the performances met the European requirements (decision 2015/495/EU) in terms of limit of quantification (LQ) and measurement uncertainty. For 17alpha-ethinylestradiol, the challenging LQ of 0.035 ng L^-1 was reached. More generally, for 15 compounds out of 21, the accuracy, evaluated in intermediate precision conditions at concentrations ranging between 0.1 and 10 ng L^-1, was found to be within a 35% tolerance. The evaluation of the measurement uncertainty was realized following the Guide to the expression of Uncertainty in Measurement. Finally, a water monitoring survey demonstrated the suitability of the method and pointed out the contamination of Belgium rivers by five estrogens (17alpha-ethinylestradiol, estriol, 17alpha-estradiol, 17beta-estradiol, and estrone) and three glucocorticoids (betamethasone, cortisol, and cortisone) which have been up to now poorly documented in European rivers.

A review of statistical strategies to integrate biomarkers of chemical exposure with biomarkers of effect applied in omic-scale environmental epidemiology

Humans are exposed to a growing list of synthetic chemicals, some of them becoming a major public health concern due to their capacity to impact multiple biological endpoints and contribute to a range of chronic diseases. The integration of endogenous (omic) biomarkers of effect in environmental health studies has been growing during the last decade, aiming to gain insight on the potential mechanisms linking the exposures and the clinical conditions. The emergence of high-throughput omic platforms has raised a list of statistical challenges posed by the large dimension and complexity of data generated. Thus, the aim of the present study was to critically review the current state-of-the-science about statistical approaches used to integrate endogenous biomarkers in environmental-health studies linking chemical exposures with health outcomes. The present review specifically focused on internal exposure to environmental chemical pollutants, involving both persistent organic pollutants (POPs), non-persistent pollutants like phthalates or bisphenols, and metals. We identified 42 eligible articles published since 2016, reporting 48 different statistical workflows, mostly focused on POPs and using metabolomic profiling in the intermediate layer. The outcomes were mainly binary and focused on metabolic disorders. A large diversity of statistical strategies were reported to integrate chemical mixtures and endogenous biomarkers to characterize their associations with health conditions. Multivariate regression models were the most predominant statistical method reported in the published workflows, however some studies applied latent based methods or multipollutant models to overcome the specific constraints of omic or exposure of data. A minority of studies used formal mediation analysis to characterize the indirect effects mediated by the endogenous biomarkers. The principles of each specific statistical method and overall workflow set-up are summarized in the light of highlighting their applicability, strengths and weaknesses or interpretability to gain insight into the causal structures underlying the triad: exposure, effect-biomarker and outcome.

Endocrine Disruptor Chemicals and Children's Health

We are all exposed to endocrine-disrupting chemicals (EDCs) starting from embryonic life. The fetus and child set up crucial developmental processes allowing adaptation to the environment throughout life: they are extremely sensitive to very low doses of hormones and EDCs because they are developing organisms. Considering the developmental origin of well-being and diseases, every adult organism expresses consequences of the environment in which it developed. The molecular mechanisms through which the main EDCs manifest their effects and their potential association with endocrine disorders, such as diabetes, obesity, thyroid disease and alteration of adrenal hormones, will be reviewed here. Despite 40 years having passed since the first study on EDCs, little is yet known about them; therefore, our purpose is to take stock of the situation to establish a starting point for further studies. Since there is plenty of evidence showing that exposure to EDCs may adversely impact the health of adults and children through altered endocrine function-suggesting their link to endocrinopathies-it is essential in this context to bear in mind what is already known about endocrine disruptors and to deepen our knowledge to establish rules of conduct aimed at limiting exposure to EDCs' negative effects. Considering that during the COVID-19 pandemic an increase in endocrine disruptor effects has been reported, it will also be useful to address this new phenomenon for better understanding its basis and limiting its consequences.

Association between chemical mixtures and female fertility in women undergoing assisted reproduction in Sweden and Estonia

OBJECTIVE

Women of reproductive age are exposed to ubiquitous chemicals such as phthalates, parabens, and per- and polyfluoroalkyl substances (PFAS), which have potential endocrine disrupting properties and might affect fertility. Our objective was to investigate associations between potential endocrine-disrupting chemicals (EDCs) and female fertility in two cohorts of women attending fertility clinics.

METHODS

In a total population of 333 women in Sweden and Estonia, we studied the associations between chemicals and female fertility, evaluating ovarian sensitivity index (OSI) as an indicator of ovarian response, as well as clinical pregnancy and live birth from fresh and frozen embryo transfers. We measured 59 chemicals in follicular fluid samples and detected 3 phthalate metabolites, di-2-ethylhexyl phthalate (DEHP) metabolites, 1 paraben, and 6 PFAS in >90% of the women. Associations were evaluated using multivariable-adjusted linear or logistic regression, categorizing EDCs into quartiles of their distributions, as well as with Bayesian Kernel Machine Regression.

RESULTS

We observed statistically significant lower OSI at higher concentrations of the sum of DEHP metabolites in the Swedish cohort (Q4 vs Q1, β = -0.21, 95% CI: -0.38, -0.05) and methylparaben in the Estonian cohort (Q3 vs Q1, β = -0.22, 95% CI: -0.44, -0.01). Signals of potential associations were also observed at higher concentrations of PFUnDA in both the combined population (Q2 vs. Q1, β = -0.16, 95% CI -0.31, -0.02) and the Estonian population (Q2 vs. Q1, β = -0.27, 95% CI -0.45, -0.08), and for PFOA in the Estonian population (Q4 vs. Q1, β = -0.31, 95% CI -0.61, -0.01). Associations of chemicals with clinical pregnancy and live birth presented wide confidence intervals.

CONCLUSIONS

Within a large chemical mixture, we observed significant inverse associations levels of DEHP metabolites and methylparaben, and possibly PFUnDA and PFOA, with OSI, suggesting that these chemicals may contribute to altered ovarian function and infertility in women.

Co-exposure to phenols and phthalates during pregnancy with the difference of body size in twins at one month old

Humans are simultaneously exposed to phenols and phthalates (PAEs). However, the mixture effect of phenols and PAEs on the body size of twins is lacking. From 2016 to 2018, we recruited 228 pregnant twins and collected up to three urine samples. A total of 8 PAE metabolites and 7 phenols were detected in urine by liquid chromatography-tandem mass spectrometry. Chemical individual and mixture effects were estimated. Multivariable linear regression results presented the percentage change in twins' growth differences at one month old with maternal PAE and phenol exposure. These chemicals were positively associated with weight differences during the entire trimester. Moreover, the quantile g-computed model showed that increased urinary concentrations of all chemicals by one quartile were associated with a 22.85% (95%CI: 11.21-35.72%), 22.60% (95%CI: 12.31-33.83%), and 24.05% (95%CI: 13.11-36.05%) larger weight difference within twins in each trimester, respectively. Increasing all PAE metabolites and phenols by one quantile across the entire trimester, weight differences increased by 26.61% (95% CI: 15.79%, 38.44%), and height differences increased by 15.84% (95%CI: 3.92%, 29.13%). Co-exposure to PAEs and phenols may primarily play a role in twins' growth.

Comprehensive monitoring of a special mixture of prominent endocrine disrupting chemicals in human urine using a carefully adjusted hydrolysis of conjugates

Many xenobiotics were identified as possible endocrine disruptors during the last decades. Structural analogy of these substances to natural hormones may lead to agonists or antagonists of hormone receptors. For a comprehensive human biomonitoring of such substances, we developed a simple, reliable, and highly sensitive method for the simultaneous monitoring of the parameters bisphenol A, triclosan, methylparaben, ethylparaben, propylparaben, butylparaben, benzophenone-1, benzophenone-3, 3,5,6-trichloropyridin-2-ol, p-nitrophenol, genistein, and daidzein in urine. Thereby, optimization of the enzymatic hydrolysis and the use of β-glucuronidase from E. coli K12 as well as sulfatase from Aerobacter aerogenes ensures the acquisition of intact analytes without cleavage of ester bonds among parabens. Validation of the method revealed limits of detection between 0.02 and 0.25 µg/L as well as limits of quantification between 0.08 and 0.83 µg/L. Thereby, the use of analyte-free surrogate matrix for calibration and control material influenced the sensitivity of the procedure positively. Furthermore, excellent precision in and between series was observed. Good absolute and relative recoveries additionally proved the robustness of the multimethod. Thus, the procedure can be applied for exploring the exposome to these prominent endocrine disruptors in the general population.

Immune signaling as a node of interaction between systems that sex-specifically develop during puberty and adolescence

Adolescence is pivotal for neural and behavioral development across species. During this period, maturation occurs in several biological systems, the most well-recognized being activation of the hypothalamic-pituitary-gonadal axis marking pubertal onset. Increasing comparative studies of sex differences have enriched our understanding of systems integration during neurodevelopment. In recent years, immune signaling has emerged as a key node of interaction between a variety of biological signaling processes. Herein, we review the age- and sex-specific changes that occur in neural, hypothalamic-pituitary, and microbiome systems during adolescence. We then describe how immune signaling interacts with these systems, and review recent preclinical evidence indicating that immune signaling may play a central role in integrating changes in their typical and atypical development during adolescence. Finally, we discuss the translational relevance of these preclinical studies to human health and wellness.

Trends Toward Earlier Puberty Timing in Girls and Its Likely Mechanisms

This is the first of two installments examining early puberty in girls. The first paper will discuss secular trends in onset of puberty and the possible mechanisms to explain these developments. The potential etiologies examined will include the role of endocrine-disrupting chemicals and obesogens, the impact of body mass index and obesity, genetic and biologic pathways, and the influence of lifestyle behaviors. The second paper of the two-part series will examine the potential health impacts of early puberty on young and adult women and offer suggestions for clinical management and public health prevention.

Chemical Contamination in Bread from Food Processing and Its Environmental Origin

Acrylamide (AA), furan and furan derivatives, polycyclic aromatic amines (PAHs), monochloropropanediols (MCPDs), glycidol, and their esters are carcinogens that are being formed in starchy and high-protein foodstuffs, including bread, through baking, roasting, steaming, and frying due to the Maillard reaction. The Maillard reaction mechanism has also been described as the source of food processing contaminants. The above-mentioned carcinogens, especially AA and furan compounds, are crucial substances responsible for the aroma of bread. The other groups of bread contaminants are mycotoxins (MTs), toxic metals (TMs), and pesticides. All these contaminants can be differentiated depending on many factors such as source, the concentration of toxicant in the different wheat types, formation mechanism, metabolism in the human body, and hazardous exposure effects to humans. The following paper characterizes the most often occurring contaminants in the bread from each group. The human exposure to bread contaminants and their safe ranges, along with the International Agency for Research on Cancer (IARC) classification (if available), also have been analyzed.

Identification of substances with a carcinogenic potential in spray-formulated engine/brake cleaners and lubricating products, available in the European Union (EU) - based on IARC and EU-harmonised classifications and QSAR predictions

Spray-formulated engine/brake cleaners and lubricating agents are widely used to maintain machines. The occupational exposure to their aerosols is evident. To assess the carcinogenic potential of these products, we identified such products available in the European Union (EU). We built a database with CAS numbers of 1) mono-constituent substances, and 2) multi-constituent-substances, and unknown-or-variable-composition,-complex-reaction-products-and-biological-materials (multi-constituent/UVCBs). The compositions of multi-constituent/UVCBs were unravelled with European Chemicals Agency (ECHA) registration dossiers. To identify carcinogenic potentials, we searched for 1) International Agency for Research on Cancer (IARC) classification; 2) Harmonised classifications in Annex VI to the EU classification, labelling and packaging (CLP) Regulation; and 3) whether they had a Danish Environmental Protection Agency advisory CLP self-classification based on quantitative structure-activity relationships (QSARs) for genotoxicity and carcinogenicity in the Danish (Q)SAR Database. In 82 products, we identified 332 mono-constituent substances and 44 multi-constituent/UVCBs. Six substances were either IARC 1 or 2B classified. Twelve mono-constituent substances and 22 multi-constituent/UVCBs had harmonised classifications as Carcinogenic Category 1A, 1B or 2, while nine substances fulfilled the QSAR-based advisory self-classification algorithms for mutagenicity or carcinogenicity. At the product level, 39 products contained substances of carcinogenic concern by either IARC, harmonised classification or QSAR. We conclude that in the investigated EU marketed spray-formulated engine/brake cleaners and lubricants, 24 of 332 mono-constituent substances and 28 of 44 multi-constituent/UVCBs had a carcinogenic potential. At the product level, 39 of 82 contained substances with an identified carcinogenic potential. Regulators and manufacturers can use this determination of carcinogenic potential to decrease occupational risk.

Inhalable particle-bound marine biotoxins in a coastal atmosphere: Concentration levels, influencing factors and health risks

Characterizing marine biotoxins (MBs) composition in coastal aerosol particles has become essential to tracking sources of atmospheric contaminants and assessing human inhalable exposure risks to air particles. Here, coastal aerosol particles were collected over an almost 3-year period for the analysis of eight representative MBs, including brevetoxin (BTX), okadaic acid (OA), pectenotoxin-2 (PTX-2), domoic acid (DA), tetrodotoxin (TTX), saxitoxin (STX), ciguatoxin (CTX) and ω-Conotoxin. Our data showed that the levels of inhalable airborne marine biotoxins (AMBs) varied greatly among the subcategories and over time. Both in daytime and nighttime, a predominance of coarse-mode AMB particles was found for all the target AMBs. Based on the experimental data, we speculate that an ambient AMB might have multiple sources/production pathways, which include air-sea aerosol production and direct generation and release from toxigenic microalgae/bacteria suspended in surface seawater or air, and different sources may make different contribution. Regardless of the subcategory, the highest deposition efficiency of an individual AMB was found in the head airway region, followed by the alveolar and tracheobronchial regions. This study provides new information about inhalable MBs in the coastal atmosphere. The coexistence of various particle-bound MBs raises concerns about potential health risks from exposure to coastal air particles.

In utero exposure to a mixture of the perfluoroalkyl-isopropyl pesticide pyrifluquinazon with dibutyl phthalate cumulatively disrupts male rat reproductive development via different mechanisms of action

Administration of individual chemicals and mixtures during sexual differentiation that disrupt the androgen signaling pathway can induce reproductive abnormalities in male rats. In the current study, we co-administered the heptafluoroisopropyl pesticide pyrifluquinazon (PFQ), and dibutyl phthalate (DBP) to pregnant rats during sexual differentiation of the reproductive tract. Both chemicals have been shown to disrupt reproductive tract differentiation in a dose-related manner reducing male anogenital distance (AGD), permanently reducing androgen-dependent tissue weights and sperm counts, and inducing reproductive malformations in male offspring, albeit by different mechanisms of action that converge downstream in the androgen signaling pathway on a common key event. Rats were orally dosed from gestation days 14-18 with dilutions of PFQ and DBP at 0, 12.5, 25, 50, 75 and 100% of the top dose (100 mg/kg PFQ and 750 mg/kg DBP). The mixture ratio was selected such that each chemical would contribute equally to multiple effects on the male offspring reproductive tract and the dose range was designed to determine if the mixture produced additive effects predicted by dose addition or response addition models, or whether significant interactions occurred. Observed data were compared to dose and response addition model predictions. As hypothesized, the mixture reduced F1 male AGD, reproductive organ weights and sperm counts and induced hypospadias with dose addition consistently providing a better prediction of the observed effects than response addition. These results support our hypothesis that chemicals that disrupt the androgen signaling pathway induce dose-additive male reproductive abnormalities regardless of the specific mechanism of action.

Prenatal exposure to pesticide residues in the diet in association with child autism-related traits: Results from the EARLI study

Prior work has suggested associations between prenatal exposure to several classes of pesticides and child autism spectrum disorder (ASD). We examined a previously developed pesticide residue burden score (PRBS) and intake of high pesticide residue foods in association with ASD-related traits. Participants were drawn from the Early Autism Risk Longitudinal Investigation (EARLI) (n = 256), a cohort following mothers who previously had a child with ASD through a subsequent pregnancy and that child's development. ASD-related traits were captured according to total Social Responsiveness Scale (SRS) scores at age 3 (mean raw total SRS score = 35.8). Dietary intake was assessed through a food frequency questionnaire collected during pregnancy. We also incorporated organic intake and fatty foods in modified versions of the PRBS. Associations between high-residue fruit and vegetable intake, the overall PRBS and modified versions of it, and SRS scores were assessed using multivariable linear regression. Overall, we did not observe associations between pesticide residues in foods and ASD-related outcomes, and modified versions of the PRBS yielded similar findings. However, reductions in ASD-related traits were observed with higher overall fruit and vegetable intake (adjusted estimates for Q4 vs. Q1: β -12.76, 95%CI -27.8, 2.3). Thus, findings from this high familial probability cohort did not suggest relationships between pesticide residues in the diet according to the PRBS and ASD-related traits. Beneficial effects of fruit and vegetable intake may influence these relationships. Future work should consider fruit and vegetable intake in association with ASD-related outcomes. LAY SUMMARY: Diet is the main source of exposure to most pesticides in use today. In this study, we examined the relationship between pesticide exposure from residues in the diet during pregnancy and child autism-related traits. We found that these pesticide residues from the diet were not related to child autism-related outcomes at age three. However, higher prenatal fruit and vegetable intake was associated with reductions in child autism-related traits.

Risk assessment of consumer spray products using in vitro lung surfactant function inhibition, exposure modelling and chemical analysis

Consumer spray products release aerosols that can potentially be inhaled and reach the deep parts of the lungs. A thin layer of liquid, containing a mixture of proteins and lipids known as lung surfactant, coats the alveoli. Inhibition of lung surfactant function can lead to acute loss of lung function. We focused on two groups of spray products; 8 cleaning and 13 impregnation products, and in the context of risk assessment, used an in vitro method for assessing inhibition of lung surfactant function. Original spray-cans were used to generate aerosols to measure aerodynamic particle size distribution. We recreated a real-life exposure scenario to estimate the alveolar deposited dose. Most impregnation products inhibited lung surfactant function at the lowest aerosolization rate, whereas only two cleaning products inhibited function at the highest rates. We used inhibitory dose and estimated alveolar deposition to calculate the margin of safety (MoS). The MoS for the inhibitory products was ≤1 for the impregnation products, while much larger for the cleaning products (>880). This risk assessment focused on the risk of lung surfactant function disruption and provides knowledge on an endpoint of lung toxicity that is not investigated by the currently available OECD test guidelines.