Chemosphere

Pesticide use is ubiquitous. While pesticide resistance in target species such as insects is a well-known phenomenon, it is less known how pesticide exposures affect the genetics of non-target species. Here, we demonstrate the research value of integrating existing datasets to study the relationship between chemicals and biodiversity from the genetics perspective by analyzing spatial pesticide concentration data and genetic data from Europe that were not initially generated for toxicological purposes. Specifically, we found associations between environmental pesticide concentrations and genetic variation (i.e., single nucleotide polymorphisms, SNPs) in a non-target species, the wild boar. Gene Ontology (GO) terms and biological signaling pathways related to nervous system function were overrepresented for the impacted genes, especially for insecticides and fungicides. Further, we found that external studies characterizing the molecular mechanisms of these pesticides revealed the same pesticide - GO relationships as those observed in our analysis. Our results show that pesticide-induced genetic changes may not be constrained to target species but may also have an impact on the long-term viability of other wildlife populations. We therefore encourage further research into this area and collaboration across disciplines to develop more comprehensive designated datasets for such analyses. This finding also urges the consideration and inclusion of chemical exposure into conservation protection strategies and greater consideration of genetic impacts from chemicals in environmental risk assessment.

Environmental exposure involves pollutant mixtures. Building on evidence that individual bisphenols alter zebrafish larval physiology and transcriptomic profiles at ng/L concentrations, we assessed the effects of specific mixtures of BPS, BPF, and BPAF without (M1) or with (M2) BPA. Experimentally, M1 and M2 induced 4.16% and 6.54% mortality in zebrafish larvae, despite the concentration addition model predicting no toxicity. Both mixtures reduced swimming-locomotor activities. These behaviors were accompanied by organ-level functional defects, as in vivo optical mapping revealed bradycardia and increased high-frequency (30-80 Hz) brain oscillations for both mixtures, while M2 additionally altered low-frequency (0.2-4 Hz) brain activity. The neurophysiological changes were accompanied by neurovascular remodeling, with in vivo two-photon microscopy revealing decreased vascular length and branching. Finally, transcriptomic analysis revealed common M1- and M2-induced alterations linked to pathways of vascular function, neuronal communication, and metabolism. M2 altered additional pathways of cardiac and neuronal signaling, consistent with the reported organ-physiology effects. We discuss the environmental relevance of mixture exposures and assess whether BPA intensifies mixture-induced responses.

Benzyl paraben (BzP) and butyl paraben (BuP) are used as preservatives and antimicrobial agents in cosmetics, pharmaceuticals, and foods. BzP and BuP have been detected in urine, placental tissue, and ovarian follicular fluid and are understudied with regards to their endocrine activity, raising concerns on their impact to the reproductive system. We tested the hypothesis that BzP and BuP are toxic to the ovary and behave similarly to other structurally similar endocrine disrupting chemicals, such as phthalates and terephthalates, by altering hormone levels and impacting cell growth and gene expression in vitro. Untreated mouse antral follicles were exposed to vehicle, 0.1, 1, 10, or 100 g/mL BzP, BuP, or the BuP analog monobutyl terephthalate (MBuTP) for 96 hours. The highest dose of BzP and BuP were cytotoxic to follicles, suggesting that medium chain length hydroxybenzoates are more cytotoxic to the ovary than corresponding terephthalic acids. BzP significantly increased levels of estradiol and testosterone compared to control. BuP decreased follicle growth and disrupted expression of cell cycle regulators, similar to phthalates. The peroxisome proliferator-activated receptor gamma (PPARg)-transcriptionally controlled gene Fabp4 was significantly upregulated by both BzP and BuP, whereas MBuTP upregulated all four PPAR target genes and decreased follicle growth. Overall, BzP, BuP, and MBuTP disrupted hormone levels, follicle growth, and cell cycle progression, suggesting similarities in toxicity to phthalates and potential endocrine disruption. Further study should be done on the reproductive toxicity and endocrine disrupting effects of chemicals similar in structure to phthalates to reduce exposure to endocrine disruptors and inform design of safer replacements.

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with the potential to disrupt metabolic processes and contribute to carcinogenesis; however, molecular evidence linking alternative and emerging PFAS to ovarian cancer (OC) remains limited. We conducted a biomarker-based case-control study integrating exposureomics with multi-omics profiling. Plasma samples from 128 patients with OC and 128 controls were analyzed for 26 PFAS, untargeted metabolomics, lipidomics, and clinical phenotypes, while urine samples from an additional 100 patients and 100 controls underwent untargeted metabolomic and clinical profiling. Single-compound, burden-based, and mixture models were integrated with PFAS-omics association scans, cross-matrix metabolite prioritization, observational exposure-omics-clinical association-chain analyses, and repeated internal cross-validation. Higher PFAS burdens were consistently associated with OC case status, and DONA, GenX, PFNA, PFPeS, PFUdA, and PFTrDA constituted an OC-prioritized six-PFAS mixture. DONA and GenX exhibited the broadest lipid-related bridging signals, particularly across phospholipids, lysophospholipids, sphingolipids, neutral lipids, and acylcarnitines. Integrated plasma and urine analyses further identified five shared metabolites-elaidic acid, hippuric acid, betaine, corticosterone, and taurocholic acid-that provided incremental and complementary discrimination beyond reference models based on clinical variables and tumor markers in internal cross-validation. Collectively, these findings demonstrate that both alternative and emerging PFAS are associated with a distinct OC-related molecular phenotype involving coordinated lipidomic, metabolomic, and hematologic alterations, while highlighting DONA and GenX as the most prominent exposure-related signals.

BACKGROUND: Pesticides are extensively used in agriculture, raising concerns about their potential impact on human health through dietary and environmental exposure. OBJECTIVES: This study evaluated the in vitro cytotoxicity of ten commonly used pesticides and their mixtures (lambda-cyhalothrin, cypermethrin, deltamethrin, tebuconazole, glyphosate, acetamiprid, cyprodinil, piperonyl butoxide, fluopyram, and imazalil) on human intestinal Caco-2 cells. METHODS: Cytotoxicity was assessed using the MTT assay, as a measure of metabolic activity, and the trypan blue exclusion test, as an indicator of cell membrane integrity. FINDINGS: Results showed that high concentrations (100 mg/L) of all pesticides significantly reduced cell viability and vitality. Notably, glyphosate and tebuconazole exhibited significant toxicity even at lower concentrations, respectively 0.1 mg/L and 10 mg/L. Combination treatments (Top 3 and Top 8 pesticide mixtures) retained the cytotoxic effects observed for individual compounds, showing additive (non-synergistic) effects. CONCLUSIONS: Overall, these findings indicate that certain pesticides-based herbicides can exert cytotoxic effects on intestinal cells even at relatively low concentrations and highlight the importance of using the component-based approach in mixture risk assessment for humans. This study was performed as part of the EU SPRINT (Sustainable Plant Protection Transition: A Global Health Approach) project.

Current insecticide toxicology still lacks an integrated understanding of how lethal and sublethal exposure shape organismal performance across biologically and environmentally relevant contexts. In particular, insecticide susceptibility may vary with physiological state, environmental conditions, and recent exposure history, factors that are only partially captured by standardized toxicity assessments. Here, using Drosophila melanogaster, we systematically compared responses to three insecticides with distinct modes of action - acetamiprid, chlorantraniliprole, and deltamethrin - across developmental stages, sexes, adult ages, and ambient temperatures. Insecticide sensitivity varied substantially across these conditions, with temperature modulating toxicity in a compound-dependent manner. Notably, deltamethrin caused substantial lethality at concentrations more than 10,000-fold below approved field application rates. Beyond these context-dependent differences in acute toxicity, sublethal pre-exposure to each insecticide rapidly reduced lethality during a subsequent challenge with the same compound, with increased tolerance already detectable after 24 h. Importantly, these exposure conditions that enhanced insecticide tolerance were associated with reduced resistance to environmental challenges, including heat and nutrient starvation, revealing a potential trade-off in organismal stress resilience. Acetamiprid exposure further altered reproductive performance in a concentration-dependent manner, with higher exposure reducing egg production while increasing developmental success among the resulting offspring, such that the number of offspring reaching adulthood remained largely unchanged. Together, these findings demonstrate that insecticide susceptibility is highly context dependent and can be rapidly modified by recent exposure history. We identify short-term, compound-specific, and potentially costly tolerance as an underappreciated consequence of insecticide exposure and highlight the importance of incorporating biological context, environmental conditions, and sublethal exposure history into pesticide risk assessment.

Human metabolism converts inorganic arsenic to the pentavalent methylated species MMA(V) and DMA(V), the forms most people excrete, and the forms long read as the end of a detoxification pathway. Whether a transporter sets how much of these metabolites reaches the genome has not been tested in a mammalian cell. We expressed human AQP3, AQP7, AQP9 or AQP10 in HEK293T and MRC5-SV40 cells and measured gamma-H2AX by flow cytometry across dose series of As(V), MMA(V) and DMA(V), pairing every aquaporin with a GFP-Tubulin control and an untransfected mock acquired in the same replicate. As(V) was inactive in HEK293T cells and only weakly active in MRC5-SV40 cells to 20 micromolar, and both methylated species damaged DNA only in the millimolar range, DMA(V) being the more potent of the two in both cell lines. Against that weak baseline, AQP9 and AQP10 raised DMA(V)-induced gamma-H2AX in HEK293T cells by roughly 17 percentage points over the matched control, more than doubling the damage the same exposure produced in control cells, whereas AQP3 and AQP7 changed it not at all. AQP9 alone remained active with MMA(V). The ranking held in MRC5-SV40 fibroblasts at one-sixth the size, and within single wells the damage rose with the amount of AQP9 a cell carried while the control was flat. Aquaglyceroporins therefore discriminate among arsenic species, and AQP9 and AQP10 turn a weakly genotoxic metabolite into a substantially more genotoxic one.

Lead (Pb) exposure is strongly associated with cardiovascular diseases, but the effects of developmental Pb exposure on the electrophysiological properties of human cardiomyocytes have not yet been investigated. Using human induced pluripotent stem cell (iPSC)-derived cardiomyocytes, we investigated the effects of human-relevant Pb exposure during ventricular cardiomyocyte differentiation on action potential properties and calcium dynamics in differentiated myocytes. We exposed 2 iPSC lines, from 1 male and 1 female donor, to Pb (0.5 or 5 micromolar) or control during only the first 8 days of differentiation, prior to functional maturation. Differentiation was carried out using an established protocol involving temporal modulation of Wnt signaling, followed by purification and maturation of contractile myocytes. We measured action potential properties and calcium dynamics using fluorescent dyes and optical mapping. We hypothesized that Pb exposure would adversely affect cardiomyocyte function, with effects persisting after cessation of exposure. In keeping with this hypothesis, we found significant Pb-induced changes in calcium (Ca) transients and action potential dynamics that were concentration and cell line specific and persisted well after exposure had ended. In the female cell line, beat frequency significantly increased with Pb exposure for both action potentials and Ca transients, while in the male cell line, beat frequency significantly decreased with Pb exposure for action potentials and increased for Ca transients. For voltage measurements, we observed significantly increased arrythmias with Pb exposure in both cell lines. Significant changes in repolarization and recovery time (for voltage and Ca, respectively) were present with Pb exposure in both cell lines. Gene expression of Ca transporters/channels and K channels were not affected, suggesting that persistent effects of Pb exposure on cardiomyocyte electrophysiology may occur through post-translational mechanisms. Overall, this study paves the way for future work to examine how exposure to Pb impacts long-term cardiac function through developmental programming.

Objective: Environmental pollutants are increasingly recognized as potential risk factors for metabolic dysfunction-associated steatotic liver disease (MASLD), yet the effects of mixed exposures and underlying mechanisms remain unclear. We evaluated associations between environmental chemical mixtures and MASLD and the mediating role of inflammation-related biomarkers. Methods: We analyzed 60 environmental chemicals across six categories among 39,061 U.S. adults from the National Health and Nutrition Examination Survey (NHANES) 1999-2020. Principal Component Pursuit with Principal Component Analysis (PCP-PCA) identified latent exposure patterns. MASLD was identified using multisociety Delphi consensus criteria and the Hepatic Steatosis Index (HSI [&ge;] 36). Logistic regression, restricted cubic spline models, and mediation analysis were applied. Results: PCP-PCA generated 5-17 dimensions per chemical category, with first-dimension variance contributions ranging from 30.70% to 98.88%. Six dimensions from four categories were retained, with phthalate esters (PAEs) and organophosphate flame retardants (OPFRs) showing the most consistent associations with MASLD. PAEs Dim.1, explaining 90.71% of variance, showed a significant non-linear dose-response association (P-nonlinear = 0.0001). Significant associations were identified for mono-isobutyl phthalate (MiBP; OR 1.12, 95% CI 1.07-1.19), mono(carboxyoctyl) phthalate (MCOP; OR 1.08, 95% CI 1.02-1.14), mono(carboxynonyl) phthalate (MCNP; OR 1.12, 95% CI 1.03-1.21), and bis(1,3-dichloro-2-propyl) phosphate (BDCP; OR 1.15, 95% CI 1.08-1.23). C-reactive protein (CRP) and red cell distribution width (RDW) were the primary mediators, accounting for 32.42% and 19.62% of the MiBP-MASLD association, respectively (both p < 0.0001). Conclusion: Environmental co-exposure, particularly to PAEs and OPFRs, was associated with higher MASLD risk, with systemic inflammation potentially contributing to these associations.

BACKGROUND Botanicals are widely consumed as herbal remedies and plant-derived products, but their complex and variable chemical composition presents major challenges for safety assessment. Although hepatotoxicity has been reported for several botanicals, the constituent compounds responsible and the underlying mechanisms often remain poorly characterised. OBJECTIVES We aimed to determine whether Cell Painting could identify candidate constituent drivers of botanical bioactivity and generate hypotheses about potential mechanisms of action in primary human hepatocytes. METHODS We profiled 13 botanical extracts and 85 known constituents across multiple concentrations using Cell Painting alongside assays of metabolic activity and membrane integrity. To interpret morphological phenotypes, we trained machine-learning models using a Cell Painting reference atlas of >1,000 chemicals linked to ToxCast/Tox21 molecular and cellular bioactivity annotations. RESULTS Cell Painting detected bioactivity in 11/13 botanical extracts and 46/85 constituents, compared with 9/13 extracts and 40/85 constituents in the cell-health assays, and generally detected activity at lower concentrations. For 9/13 extracts, at least one constituent was active at a lower concentration than the corresponding botanical extract, supporting the contribution of a subset of potent constituents to mixture-level responses. Aristolochia and goldenseal were the most potent extracts across Cell Painting and cell-health assays and contained highly active constituents. Reference-atlas models generated specific mechanistic hypotheses, including cytotoxicity-, endocrine-, and genotoxicity-associated responses for several botanicals and constituents. CONCLUSION These results support Cell Painting combined with machine learning as a sensitive approach for characterising cellular responses to botanicals, prioritising candidate constituent drivers of hepatotoxicity-associated phenotypes, and generating testable hypotheses about potential mechanisms of action.

Total serum perfluorooctane sulfonate (PFOS) concentration and its isomer composition describe different aspects of internal exposure, but their respective associations with depressive symptoms remain uncertain. We examined adults aged 18-25 years in NHANES August 2021-August 2023 using survey-weighted models of the Patient Health Questionnaire-9 (PHQ-9). Total measured PFOS was the sum of linear PFOS and pooled monomethyl-branched PFOS; composition was their log-ratio. The analytic cohort included 169 participants, with 147 complete cases for core adjustment. Median total PFOS was 1.70 ng/mL, the median linear fraction was 72.2%, and the weighted prevalence of PHQ-9 [&ge;]10 was 22.6%. In the joint adjusted model, a doubling of total PFOS at fixed composition corresponded to -0.49 PHQ-9 points (95% CI, -1.65 to 0.68); a doubling of the linear-to-branched ratio at fixed total corresponded to 0.21 points (-1.94 to 2.36). Algebraic rescaling across the reported interquartile ranges yielded differences of -0.58 points (-1.95 to 0.81) for total PFOS and 0.13 points (-1.16 to 1.41) for composition. The inverse continuous-score association weakened with adjustment, whereas the screening odds ratio primarily lost precision. Excluding three observations with an isomer below detection shifted both joint coefficients. The data therefore do not establish an independent composition association or equivalent isomer effects. Experimental evidence supports candidate oxidative, inflammatory, and synaptic pathways, but differential protein binding and elimination prevent a serum composition ratio from being interpreted directly as brain dose or toxicity. Larger longitudinal analyses with isomer-resolved exposure and toxicokinetic measurements are needed to test these pathways.

Micro/nanoplastics (MNPs) are increasingly recognized as a persistent environmental contaminant of concern, yet polyisobutylene (PIB), an industrially significant polymer used as industrial sealants, adhesives, cable insulation, lubricant additives, and chewing gum bases, remains poorly studied relative to more commonly studied plastics such as polyethylene terephthalate (PET), polystyrene (PS), and polyethylene (PE). This study investigated the multisystem toxicological effects of chronic dietary exposure to PIB-MNPs in Drosophila melanogaster. PIB-MNPs (> 5 micron) were synthesized via the solvent evaporation method and characterized using scanning electron microscopy (SEM) and Fourier Transform Infrared spectroscopy (FTIR), confirming successful synthesis. Flies were chronically exposed to PIB-MNPs (1, 2, or 3 mg) alongside an SDS control and a water control to 50 mg of yeast over 21 days, with toxicological outcomes assessed via survival analysis, climbing assays, fluorescence brain imaging, fertility/fecundity assays, the Smurf gut-permeability assay, Ellman's AChE activity assay, and RT-qPCR analysis of Stat92E expression, a marker of inflammation. Chronic exposure to PIB-MNPs reduced survival, with females exhibiting markedly greater susceptibility than males. Exposure progressively impaired locomotor performance and induced brain vacuolization suggestive of neurodegeneration, peaking at day 15. AChE activity declined in a concentration-dependent manner by day 21. Female fecundity, egg-hatching rate, and ovarian egg-chamber maturation were significantly reduced, while male gonadal cyst cell numbers remained largely unaffected. PIB-MNPs exposure also induced a positive Smurf phenotype, indicating compromised intestinal barrier integrity and upregulated Stat92E expression, consistent with activation of a systemic stress response. Notably, several endpoints showed non-monotonic, concentration-independent trends, suggesting particle aggregation may influence effective bioavailability. Collectively, these findings establish PIB-MNPs as a multi-system toxicant in Drosophila.

Introduction: Pesticide exposure has been associated with poorer mental health, yet little is known about whether seasonal fluctuations in agricultural pesticide use are associated with cyclical changes in mood among people living in agricultural communities. We evaluated associations between 10 peak and off-peak pesticide spray seasons and ecological momentary assessment (EMA)-derived mood in a floricultural region in Ecuador. Methods: 496 participants completed repeated EMA surveys across 10 assessment administrations over 2.5 years (2022-2024), including one single-assessment administration and nine 10-day bursts (Nobservations=14,332). Mood outcomes included negative affect (sadness, anxiety, stress, anger, tiredness, difficulty concentrating; overall mean=2.79, Standard Deviation [SD]=1.32), positive affect (happiness, motivation; overall mean=4.21, SD=1.60), and behavioral dysregulation (aggression and impulsivity, overall mean=1.86, SD=1.29). Generalized linear mixed models estimated pooled, between-person and within-person associations between peak pesticide spray seasons and mood, adjusting for demographic and longitudinal factors Effect modification by sex, floricultural occupation, and cohabitation with a floricultural worker was assessed. Results: Peak spray seasons were associated with higher negative affect ({beta}=0.11 [0.06, 0.16]) and behavioral dysregulation ({beta}=0.10 [0.05, 0.15]) but not positive affect ({beta}=0.01 [-0.05, 0.07]). Associations were driven by within-person changes. Sex modified associations with negative affect, which were stronger in males than females. Floricultural occupation modified associations, with poorer mood, greater behavioral dysregulation and lower positive affect among floricultural workers than non-workers. Discussion: Peak pesticide spray seasons were associated with worsening of negative affect and behavioral dysregulation. EMA may provide a sensitive approach for detecting short-term neurobehavioral changes associated with seasonal pesticide exposure.

Per- and polyfluoroalkyl substances (PFAS) are present throughout the environment due to decades of use in many commercial products and industrial processes. These molecules contain a hydrophobic fluorocarbon tail and a functional headgroup (typically a carboxylic or sulfonic acid) that allows hydrophilic interactions with the surrounding environment. These properties make them inherently resistant to degradation, difficult to track through the environment, readily bioaccumulative, and likely to impact human health. Through collaboration with town officials, multiple meetings with local sustainability committee members and school officials, and direct contact with individual homeowners, we conducted community-driven sampling of PFAS in well water from 105 houses in Tremont, ME, a rural coastal town that relies on private wells for drinking water. The rate of PFAS detection for one or more analytes across all wells (N=105) was 69%. Of all wells tested, 16 (15%) exceeded the current public drinking water standard in Maine (20 ng/L for 6 PFAS), and an additional 17 (totaling 31% of all wells tested) exceeded Maine's newly adopted public drinking water standards for the state (based on EPA 2024 standards). Because private wells are unregulated, homeowners may use these results as a guide for taking action to maintain safe drinking water. Both hierarchical cluster analyses and pairwise Spearman's rank correlation of PFAS test results revealed similar profiles in households near and far from one another. Along with the absence of obvious, large-scale potential point sources of PFAS contamination, these findings support septic systems as the primary source of PFAS contamination in drinking water across this town. The community-driven approach to the sampling effort has enabled information sharing on the importance of water filtration options, discussion of long-term pollution abatement strategies for individual households and the town, and focused efforts for future well water testing and PFAS mitigation.

Inhalation of airborne per- and polyfluoroalkyl substances (PFAS) represents an important yet understudied exposure route. While volatile organic compounds (VOCs) have been widely explored as biomarkers of toxicant exposure, their potential for early detection of PFAS-induced pulmonary toxicity remains largely unexplored. This study investigated VOC profiles in human alveolar (A549) and bronchial (BEAS-2B) epithelial cells following exposure to environmentally relevant PFAS concentrations (1, 5, and 10 ppb) for 12, 24, and 48 h. VOCs were analyzed using headspace solid-phase microextraction coupled with gas chromatography-Orbitrap mass spectrometry. We observed significant concentration- and time-dependent alterations in VOC profiles in both cell models. The principal VOCs associated with PFAS exposure include butanal, acetone, 2-butanone, 2-nonanone, (E)-2-nonenal, (E)-2-octenal, (E)-2-heptenal, 2,4-heptadienal, 2,4-nonadienal, 2,4-decadienal, 1-pentanol, and 1-hexanol. Cell type-specific regulations were observed, reflecting differential metabolic responses between transformed and non-transformed lung epithelial cells. Metabolite set enrichment analysis indicated perturbations in ketone body metabolism, consistent with altered cellular energy metabolism. Complementary qPCR analysis revealed altered expressions of CYP1A1, CYP2E1, ALDH1A1, and ALDH2, supporting a mechanistic link between PFAS exposure and oxidative stress, lipid peroxidation, and impaired aldehyde detoxification. These findings demonstrate that VOC profiling, combined with transcriptional analysis, can reveal PFAS-induced metabolic perturbations in pulmonary epithelial cells.

Per- and polyfluoroalkyl substances (PFAS) and phthalate metabolites are understudied in follicular fluid of women undergoing assisted reproduction. We characterized these in previously collected follicular fluid from patients at a Nebraska fertility clinic (August 2022 to June 2025) and retrieved demographics and clinical characteristics from fertility records. Spearman correlations and nonparametric tests evaluated PFAS and phthalate correlations and exposure differences by age, race, BMI, and urbanicity. Seven PFAS and four phthalate metabolites were detected in at least half of participants. PFOS and PFHxS concentrations were higher in younger women, and mono-isobutyl phthalate (MiBP) was higher in younger and non-White women. PFAS and phthalate correlations were weak, and exposures did not differ by urbanicity, indicating multiple chemical exposures in follicular fluid with sociodemographic disparities.

Abstract: Background: Children born very preterm (VPT) are at elevated risk for adverse neurobehavioral outcomes and are vulnerable to environmental exposures. We used untargeted metabolomics analysis to identify environmentally relevant metabolites associated with childhood behavioral problems and to characterize related endogenous metabolic pathways. Methods: We studied 226 children born <30 weeks gestation in a multi-site cohort study. Urine collected at age 4 was profiled using untargeted ultra-high-performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS). Associations between 30 exogenous environmental metabolites and behavioral problems score at age 4 were evaluated cross-sectionally using multivariable linear regression, followed by metabolome-wide association and pathway enrichment analyses. Results: Three exogenous metabolites were nominally associated with child behavior problems. Specifically, 2-(Acetylamino)-3-( henylthiol)propanoic acid was positively associated with overall ({beta}=1.42, p=0.006), externalizing ({beta}=1.50, p=0.006), and internalizing ({beta}=1.34, p=0.021) behavior problems. Diethofencarb was positively associated with overall ({beta}=0.34, p=0.018) and externalizing ({beta}=0.39, p=0.010) behavior problems, while protocatechuic acid was inversely associated with internalizing problems ({beta}=-0.68, p=0.027). No associations remained significant after false discovery rate (FDR) correction. Nevertheless, these metabolites were associated with 151, 131, and 530 endogenous metabolic features, respectively, at FDR<0.05, highlighting perturbations in lipid metabolism, mitochondrial energetics, inflammatory signaling, amino acid metabolism, and neuroactive pathways. Conclusions: Environmental metabolites associated with behavior problems were linked to broad endogenous metabolic differences relevant to neurodevelopment. These findings highlight potentially modifiable environmental influences, including exposures related to combustion-derived pollutants, pesticides, and dietary sources, that may contribute to behavioral vulnerability among children born very preterm

Background: Guanica, Puerto Rico, has one of the highest concentrations of environmental polychlorinated biphenyls (PCBs). This PCB contamination coupled with persistent poverty, population loss, and repeated environmental disasters has taken a heavier toll on Guanica community. Our environmental sampling has documented high levels of PCBs in sediment, air and fish, but far less is known about how residents themselves understand exposure, interpret health risk, and weigh contamination against the other pressures of daily life. Methods: We used a qualitative descriptive design nested within the larger HELP Study. This paper presents the final analysis of all qualitative data collected in Guanica: ten sessions comprising five focus groups and five interviews with fishermen (N = 31), conducted between November 2024 and October 2025 in familiar community settings. Sessions followed a semi-structured guide translated from English to Spanish and back-translated for accuracy. Recordings were transcribed in Spanish, verified against the audio, and analyzed in NVivo using codebook-style thematic analysis; three bilingual researchers coded collaboratively and resolved disagreements by consensus. Results: Five themes emerged from our analysis concerning how residents and fishermen understand and navigate PCB contamination: (1) perceived community decline shapes how residents prioritize environmental risks; (2) limited knowledge, misinformation, and communication gaps affect understanding of PCB contamination; (3) cancer concerns are high, but links to PCB exposure remain unclear; (4) PCB contamination is seen as a threat to livelihoods, especially fishing and tourism; and (5) deep mistrust and a desire for accountability influence perceptions of environmental interventions. Participants described contamination not as an isolated hazard but as one strand of a longer history of economic decline, disaster, and institutional neglect. Conclusions: Social, economic, and environmental conditions together shape how Guanica residents perceive contamination of their environment. Meaningful progress requires sustained community involvement, support for local initiatives, development of a Community Health Worker program, and expanded partnerships with local institutions and schools to close communication gaps and promote long-term resilience to address the health effects of PCB contamination in Guanica.

Background: Lead is a cumulative environmental toxicant for which no safe level of exposure has been identified, and pregnant women and their fetuses are particularly vulnerable because lead readily crosses the placenta and can be mobilised from maternal bone stores. Bangladesh conducted its first nationally representative blood lead testing among pregnant women through the 2025 Multiple Indicator Cluster Survey (MICS), but a detailed, multi-domain analysis of the determinants of elevated blood lead level (BLL) among this population has not yet been reported. Methods: We conducted a secondary cross-sectional analysis of 1,928 pregnant women aged 15-49 years with complete data from the women's dataset of Bangladesh MICS 2025. Elevated BLL was defined as [&ge;]5 g/dL. Survey-weighted logistic regression was used to estimate unadjusted and adjusted odds ratios (aOR) for co-exposure to arsenic, cadmium and mercury and sociodemographic and socioeconomic covariates. Slope Index of Inequality (SII) as well as Relative Index of Inequality (RII) were used to quantify wealth-related inequality. Population attributable fractions (PAF) were estimated for three counterfactual scenarios, and adaptive least absolute shrinkage and selection operator (LASSO) regression was used as a sensitivity analysis. Results: Elevated BLL was present among 6.2% of participants. In the adjusted model, a 2-fold rise in blood cadmium was associated with higher odds of elevated BLL (aOR: 1.54; 95% CI: 1.21-1.96), whereas a 2-fold rise in blood mercury (aOR: 0.63; 95% CI: 0.48-0.83), rural residence (aOR: 0.55; 95% CI: 0.32-0.94), secondary education (aOR: 0.49; 95% CI: 0.28-0.85) and post-secondary education (aOR: 0.22; 95% CI: 0.11-0.46) were associated with lower odds. Belonging to progressively wealthier quintiles was associated with markedly higher odds, BLL rising to an aOR of 10.32 (95% CI: 4.41-24.15) for the richest versus poorest quintile. The RII was 8.59 (95% CI: 4.24-17.40) and the SII was 0.159 (95% CI: 0.101-0.218), indicating a substantial pro-rich gradient in elevated BLL. Counterfactual scenarios suggested that shifting the population to secondary-level education could reduce the prevalence of elevated BLL by 52.9% (95% CI: 20.6-72.0) and shifting to rural residence by 24.3% (95% CI: 1.4-41.9). Adaptive LASSO variable selection produced estimates consistent in direction and magnitude with the fully adjusted model. Conclusion: In this national sample, approximately one out of every 16 pregnant women had blood lead levels that met or exceeded the action threshold set by the World Health Organization, with this issue being particularly prevalent among wealthier, urban, and less-educated women, and was compounded by co-exposure to cadmium. In Bangladesh, the typical pattern observed for maternal and child health indicators does not align with the inverse relationship found between household wealth and lead exposure. This suggests that the sources of exposure are not merely indicators of material poverty. Antenatal blood lead screening, source investigation, and equity-informed lead-reduction strategies that specifically reach wealthier and urban households are warranted.

Biodiversity is globally threatened by chemical pollution, yet toxicity data remain unavailable for millions of species and tens of thousands of chemicals, severely limiting our ability to assess ecological impacts. Here we present TRIDENT-2, a multimodal artificial intelligence model for predicting chemical toxicity across evolutionarily diverse eukaryotic species. Trained on 560,780 toxicity assays spanning 82,775 chemicals, 6,793 species, and multiple exposure scenarios, TRIDENT-2 accurately predicts toxicity across Eukaryota with an average median absolute error ranging from 1.76 to 3.80. By jointly learning from chemical, biological, and experimental information, it remains accurate across broad chemical and taxonomic distances, allowing for toxicity assessment for species and chemicals beyond the current experimental evidence. Our findings demonstrate that artificial intelligence can help overcome longstanding data limitations in ecotoxicology, paving the way for improved decision-making and reducing chemical impacts on biodiversity and ecosystems.