Environment International

BackgroundSeveral studies revealed an implication of air pollution in neurodegenerative disorders, although this link and the potential underlying mechanisms remain unclear. ObjectivesTo analyze the impact of air pollution on neurodegenerative risk by testing multiple pollutants simultaneously, along with other potential risk/protective factors, and the role of circulating inflammation. MethodsIn the Moli-sani cohort (N=24,325; [&ge;]35 years; 51.9% women, baseline 2005-2010), we estimated yearly levels of exposure to nitrogen oxides, ozone, particulate matter (PM10), sulfur dioxide and BTX hydrocarbons in 2006-2018, applying residence geo-localization of participants and Kriging interpolation algorithm to land measurements of air pollutants. We performed a principal component (PC) analysis of pollutant levels and tested associations of the resulting PC scores with the incident risk of dementia (AD) and Parkinsons disease/parkinsonism (PD), through multivariable Cox PH regressions adjusted for age, sex, education level, and several professional and lifestyle exposures. Moreover, we tested whether a composite biomarker of circulating inflammation (INFLA-score) may explain part of these associations. ResultsOver 24,308 subjects with pollution data available (51.9% women, mean age 55.8(12.0) years), we extracted three PCs explaining [&ge;]5% of pollution exposure variance: PC1 (38.2%, tagging PM10), PC2 (19.5%, O3/CO/SO2), PC3 (8.5%, NOx/BTX hydrocarbons). Over a median (IQR) follow-up of 11.2(2.0) years, we observed statistically significant associations of PC1 with an increased risk of both AD (HR[CI] = 1.06[1.04-1.08]; 218 cases) and PD (1.05[1.03-1.06]; 405 incident cases), independent on other covariates. These associations were confirmed testing average PM10 levels during follow-up time (25[19-31]% and 19[15-24]% increase of AD and PD risk, per 1 g/m3 of PM10). INFLA-score explained a negligible (<1%) proportion of these associations. DiscussionAir pollution - especially PM10 - is associated with increased neurodegenerative risk in the Italian population, independent on concurring risk factors, suggesting its reduction as a potential public health target.

BackgroundAryl phosphate esters (APEs), a main class of organophosphorus ester molecules, are widely used and commonly present in the environment. Health hazards associated with these compounds remain largely unknown and the effects of diphenyl phosphate (DPhP), one of their most frequent derivatives in human samples, are poorly characterised. ObjectiveOur aim was to investigate whether DPhP per se may represent a more relevant marker of exposure to APEs and determine its potential deleterious biological effects in chronically exposed mice. MethodsConventional animals (FVB mice) were acutely (intravenous or oral gavage) or chronically (0.1 mg.mL-1, 1 mg.mL-1, 10 mg.mL-1 in drink water) exposed to relevant doses of DPhP or triphenyl phosphate (TPhP), one of its main precursors in the environment. Both molecules were measured in blood and other relevant tissues by liquid chromatography-mass spectrometry (LC-MS). Biological effects of chronic DPhP exposure were addressed through liver multi-omics analysis combining mRNA extraction and sequencing to high resolution LC-MS to determine the corresponding metabolic profile. Deep statistical exploration was performed to extract correlated information, guiding further physiological analyses (immunohistochemistry (IHC) and animal growth measurement). ResultsAcute and chronic exposure to DPhP led to significant levels of this molecule in blood and other tissues, an effect missing with TPhP. Multi-omics analysis confirmed the existence of biological effects of DPhP, even at a very low dose of 0.1 mg.mL-1 in drinking water. Chemical structural homology and pathway mapping demonstrated a clear reduction of the fatty-acid catabolic processes centred on acylcarnitine and mitochondrial {beta}-oxidation. Interestingly, mRNA expression confirmed and extended these observations by demonstrating at all tested doses the overall repression of genes involved in lipid catabolic processes and regulated by PPAR, a master regulator of {beta}-oxidation and its associated ketogenesis. IHC analysis confirmed the alteration of these pathways by showing a specific downregulation of Hmgcs2, a kernel target gene of PPAR, at all doses tested, and surprisingly, a strong reduction of the lipid droplet content only at the highest dose. Overall, DPhP absorption led to weight loss, which was significant using the highest dose. ConclusionsOur results suggest that in mice, the effects of chronic exposure to DPhP, even at a low dose, are not negligible. Fatty acid metabolism in the liver in particular is essential for controlling fast and feast periods with adverse consequences on the overall physiology. Therefore, the impact of DPhP on circulating fat, cardiovascular and metabolic disease incidence deserves, in light of our results, further investigations.

Emerging studies find arteriolar dysfunction in offspring with in-utero electronic cigarette (Ecig) exposure, but the long-term effect on offsprings cerebrovascular vascular and neurocognitive health is poorly understood. Ecigs provides a unique opportunity to directly evaluate the contributions of inhaled nicotine from the vehicle e-liquid - which was not possible with traditional cigarettes. Moreover, many Ecigs have variable power settings, which can alter the toxicity of the aerosol cloud produced. We hypothesize maternal vaping at different wattages will have variable effects on cerebrovascular function in the offspring, and that these effects would be independent of nicotine. We used time-mated female Sprague-Dawley rats with Ecig exposure from gestation day (GD)2-21. We studied male and female offspring for vascular and neurocognitive function at 1-, 3-, 6- and 12-months of age. We found that, both sexes, offspring with in-utero exposure (at 5w and 30w Ecig conditions) exhibited impaired middle cerebral artery (MCA) reactivity. While the magnitude of impairment was greater at higher that lower watts, Ecig at 5-watts still exhibited significant impairments in MCA function (suggesting the harm threshold for blood vessels is very low). Vascular dysfunction was evident with or without nicotine in the e-liquid, but nicotine exposure resulted in short-term memory deficits, evidence of neuronal damage, and increased astrocyte interaction with endothelial cells in 6- and 12-month-old offspring. We also observed altered expression of clock genes and antioxidant signaling pathways, along with a decrease in sirtuin-1 expression, decreased ratio of beta-amyloid A 42/40 protein expression, and increased in NOX1, which are consistent with redox imbalance, neuroinflammation, and advancing cellular senescence. These preclinical data provide evidence suggesting that in utero exposure to Ecigs from maternal vaping can be expected to adversely affect the brain health of offspring in their adult life and that neurocognitive outcomes are worsened with exposure to nicotine. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=174 SRC="FIGDIR/small/638202v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@1e7a7a1org.highwire.dtl.DTLVardef@1ae5bceorg.highwire.dtl.DTLVardef@d323eorg.highwire.dtl.DTLVardef@5db4af_HPS_FORMAT_FIGEXP M_FIG C_FIG Created in BioRender

BackgroundFine particulate matter (PM2.5), airborne particles with an aerodynamic diameter [&le;]2.5 m that can penetrate deep into the lungs and enter the circulation, is increasingly recognized as a risk factor for chronic kidney disease (CKD) with long-term exposure. We previously demonstrated that high-dose PM2.5 exposure prior to ischemia-reperfusion injury (IRI) aggravates acute kidney injury (AKI). Here, we investigated how prolonged, low-concentration urban PM2.5 exposure (<15 {micro}g/m3) affects kidney repair after AKI. MethodsSix-week-old mice underwent bilateral IRI or sham surgery, followed by six months of exposure to either filtered air or ambient PM2.5 exposure in a unique exposome chamber. Kidneys were analyzed using pathomics, electron and super-resolution microscopy, immunohistochemistry, transcriptomics, and LC-MS lipidomics/metabolomics. Complementary in vitro hypoxia-reoxygenation and PM2.5 exposure experiments were performed in proximal tubular epithelial cells. ResultsLong-term PM2.5 exposure had minimal effects in sham-operated mice, including no significant changes in body weight or kidney function. Despite preserved kidney function, IRI+PM2.5 mice exhibited reduced weight gain, a marked expansion of the interstitial area, attributable to enhanced fibrosis and inflammatory responses, microvascular rarefaction, and endothelial-to-mesenchymal transition, consistent with maladaptive repair features. Proximal tubules displayed mitochondrial injury, glycolytic reprogramming, lipid accumulation, and a senescent phenotype. Energy Dispersive X-ray (EDX) microscopy confirmed PM2.5-derived elements within proximal tubules lysosomes, accompanied by lysosomal stress. Transcriptional signature-based drug screening identified nicotinamide as a compound capable of reversing PM2.5-induced metabolic alterations; in vitro validation confirmed restoration of mitochondrial function. ConclusionsTogether, these findings show that chronic post-AKI exposure to PM2.5 at levels currently considered safe by regulatory bodies drives maladaptive repair and accelerates CKD progression through mitochondrial dysfunction, lysosomal stress senescence in proximal tubules, due to local PM2.5 element accumulation. Translational StatementAcute kidney injury frequently progresses to chronic kidney disease due to maladaptive repair, yet environmental drivers of this transition remain underrecognized. Using a controlled exposome chamber, we demonstrate that chronic exposure to low, real-world concentrations of urban PM2.5 during post-ischemic recovery results in the accumulation of PM2.5-derived elements within proximal tubular lysosomes, leading to organelle dysfunction, metabolic reprogramming, lipid accumulation, and a senescence-like phenotype. Importantly, transcriptomics-based drug repurposing identified nicotinamide as a candidate compound capable of reversing metabolic dysfunction in injured proximal tubular cells subjected to hypoxia-reoxygenation and PM2.5 exposure, an effect validated in vitro.

ObjectiveTo investigate associations between long-term environmental exposures, both external (ambient air pollution and built environment) and internal (circulating anthropogenic chemicals), and the human plasma metabolome, with the aim of generating biologically plausible hypotheses about affected metabolic pathways. MethodsWe analyzed plasma from 989 Estonian Biobank participants using untargeted LC-HRMS (Metabolon HD4). External exposures (PM2.5, PM10, NO2, ozone and built-environment metrics) were assigned using spatiotemporally resolved models developed in the EXPANSE project. Internal exposures were defined as ubiquitous anthropogenic compounds detected in the same metabolomics dataset. Associations between exposures and individual metabolites were quantified using left-censored regression models and then mapped to metabolite classes (Metabolon) and KEGG pathways. For enrichment analyses, one-sided Kolmogorov-Smirnov tests were applied to external exposures and Fishers exact tests to internal exposures. False discovery rate was controlled at 1% per exposure and database. ResultsExternal air pollutants exhibited distinct metabolic patterns: Higher NO2 exposure was associated with enrichment of metabolites involved in tyrosine metabolism; higher ozone with monohydroxy and dicarboxylate fatty acids (consistent with lipid peroxidation); and higher PM2.5 with acyl-carnitine subclasses and carbohydrate metabolism (glycolysis / gluconeogenesis / pyruvate). Built-environment associations were heterogeneous across metabolites and pathways. Internal anthropogenic chemicals showed broader metabolic associations than external exposures, involving a larger number of metabolites and metabolic classes. PFAS (PFOA, PFOS) were associated with long-chain polyunsaturated fatty acids (n3/n6) and lysophospho-lipids. Associations with 4-hydroxychlorothalonil, a fungicide, pointed to androgenic steroid metabolites and alpha-linolenic acid metabolism. The phenolic 2,4-di-tert-butylphenol, a plastic associated chemical, showed widespread associations with lipid classes, suggesting disruption of membrane remodeling and fatty acid handling. ConclusionLong-term environmental exposures, both external and internal, are measurably reflected in the human plasma metabolome. Across exposure domains, recurrent signals involved lipid metabolism, membrane composition, and oxidative stress-related pathways, highlighting these as common biological targets of environmental exposures. The findings generate testable hypotheses, including nitrosative stress-related alterations for NO2, lipid peroxidation for ozone, energy-metabolism perturbations for PM2.5, potential endocrine activity for chlorothalonil metabolites, and possible obesogenic effects of 2,4-di-tert-butylphenol.

Prenatal exposure to environmental contaminants is a significant health concern because it has the potential to interfere with host metabolism, leading to adverse health effects in early childhood and later in life. Growing evidence suggests that genetic and environmental factors, as well as their interactions, play a significant role in the development of autoimmune diseases. In this study, we hypothesized that prenatal exposure to environmental contaminants impacts cord serum metabolome and contributes to the development of autoimmune diseases. We selected cord serum samples from All Babies in Southeast Sweden (ABIS) general population cohort, from infants who later developed one or more autoimmune-mediated and inflammatory diseases: celiac disease (CD), Crohns disease (IBD), hypothyroidism (HT), juvenile idiopathic arthritis (JIA), and type 1 diabetes (T1D) (all cases, N = 62), along with matched controls (N = 268). Using integrated exposomics and metabolomics mass spectrometry (MS) based platforms, we determined the levels of contaminants and metabolites. Differences in exposure levels were found between the controls and those who later developed various diseases. High contaminant exposure levels were associated with changes in metabolome, including amino acids and free fatty acids. Specifically, we identified marked associations between metabolite levels and exposure levels of deoxynivalenol (DON), bisphenol S (BPS), and specific per- and polyfluorinated substances (PFAS). Our study suggests that prenatal exposure to specific environmental contaminants alters the cord serum metabolomes, which, in turn, might increase the risk of various immune-mediated disease later in life.

Omic-based technologies are of particular interest and importance for non-animal chemical hazard and risk characterization based on the premise that any apical endpoint change must be underpinned by some alterations measured at the omic levels. In this work we studied cellular responses to caffeine and coumarin by generating and integrating multi-omic data from transcriptomic, proteomic and phosphoproteomic experiments. We have shown that the methodology presented here is able to capture the complete chain of events from the first compound-induced changes at the phosphoproteome level to changes in gene expression induced by transcription factors and lastly to changes in protein abundance that further influence changes at the cellular level. In HepG2 cells we found the metabolism of lipids and general cellular stress to be dominant biological processes in response to caffeine and coumarin exposure, respectively. The phosphoproteomic changes were detected early in time, at very low concentrations and provided a fast adaptive cellular response to chemical exposure. Changes in protein abundance were found much less frequently than the transcriptomic changes and can be used, together with the transcriptomic changes, to facilitate a more complete understanding of pathway responses to chemical exposure. GRAPHIC ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=169 SRC="FIGDIR/small/492410v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@1e348c8org.highwire.dtl.DTLVardef@bf50c5org.highwire.dtl.DTLVardef@4fea36org.highwire.dtl.DTLVardef@998cb8_HPS_FORMAT_FIGEXP M_FIG C_FIG

IntroductionAn increasing number of rural communities express perception of health damage from glyphosate and other agrochemicals. We measure the presence of glyphosate in the human body, in order to create, together with the local community, a systemic model that highlights modifiable causal socio-environmental conditions. Materials and methodsParticipatory Action Research. Measurement of environmental factors and self-reported oncological disease were obtained in a three-stage probabilistic sampling (blocks, houses, family) of people living in French city - 9 de Julio-Buenos Aires. Glyphosate in urine was analyzed by liquid chromatography coupled to tandem mass spectrometry. The exposure pathway was obtained by interviewing positive cases. A conceptual systemic model was designed. Resultsof the total 46 blocks of French, 23 were included with systematic sampling and from the 76 houses selected (50%) one person was included in the study. Oncological disease was reported in 21.8% of the households. 13% of the population (95% CI 6.5-23) presented quantifiable glyphosate in urine in June 2023. Occupational exposure was ruled out in all cases. The main self-reported sources were: unloading agrochemicals in the nearby warehouse, the grain storage complex, pesticide drift and self-propelled sprayers that pass by on the street, variables belonging to economic and cultural conditions. A network of actors emerged who, gathered on a website, propose actions to the mayors office. DiscussionThis study has high external validity for public health decision makers regarding the determinants. It is necessary to notify the Argentine Integrated Health System, both suspected exposure and possibly related health events, and to design how to refer human samples to highly complex laboratories to measure pesticides. Conclusionthe presence of glyphosate in urine was due to environmental exposure; It expresses a path of passive, involuntary and chronic absorption of environmental pollutants and is due to Frenchs agricultural activity with dominance of market forces in the system, poorly antagonized by care forces.

This study evaluates the association between ambient temperature exposure during pregnancy and newborn birthweight, using a penalized generalized additive model (GAM) framework with distributed lag non-linear models (DLNM) to identify sensitive windows of exposure. The analysis includes 238 participants from the SHIP study with complete temperature exposure and birthweight data. Weekly maximum temperatures during pregnancy were estimated using Daymet data, and the impact of temperature on birthweight was assessed, adjusting for maternal age, pre-pregnancy BMI, gestational age, race, smoking, diabetes status, and infant biological sex. The model incorporated a crossbasis function for temperature exposure across 42 gestational weeks and allowed penalization for smoother, data-driven lag estimation. Results from the combined-sex model indicated that higher ambient temperatures during the third trimester, particularly in the final weeks of pregnancy, were associated with increased birthweight. Stratified analyses suggested that this association was more pronounced in male infants. These findings highlight the importance of considering prenatal temperature exposures and timing when evaluating determinants of newborn health.

BackgroundBisphenols (BP) AF, B, E, F, M, and S have been introduced as substitutes for bisphenol A (BPA) and are increasingly used in consumer products. Despite widespread human exposure and potential adverse health outcomes related to BPF, BPB, BPS, and BPAF, their physiological disposition in humans is poorly characterized, which hinders assessment of associated risks. ObjectivesOur goal was to simulate the kinetic behavior of prevalent bisphenol analogs in organs of toxicological interest. To enable predictions of physiologically relevant internal concentrations of a family of structurally similar compounds with limited available human data, we aim to establish a reproducible framework using multimodal parameterization methods. MethodsHerein we developed physiologically based kinetic (PBK) models, following oral exposure. Their parametrization was primarily based on structural, physiological and experimental values, as well as quantitative structure-activity relationship (QSAR) predictions. Outputs were evaluated against available biomonitoring data for BPA and BPS. Critical parameters were identified by sensitivity analysis and iteratively re-sampled in Monte Carlo (MC) simulations to quantify uncertainties. ResultsAmong human models parametrized for males and females of different ages, we predicted that bisphenols reached the highest concentrations in 5-year-old males. Environmentally relevant exposure levels resulted in maximum concentrations in the blood and testes for BPS, and in the thyroid for BPM. After 96 hours, steady-state concentrations were not yet reached in the breasts for BPA, BPAF, BPB, BPE, BPF and BPM. ConclusionsThe data from this study suggest significant variability in internal concentrations for identical exposures to different bisphenols analogs that further depend on age, sex and organ. This diversity in toxicokinetic behavior should be considered for health risk assessment of these substitutes.

The human toxicological risk assessment of per- and polyfluoroalkyl substances (PFAS) is challenging, due to their sheer number and structural diversity, but also the paucity of the toxicity data required to characterize them. The development of Next Generation Physiologically Based Kinetic (NG-PBK) models may assist in overcoming this challenge. The mechanistic nature of NG-PBK models allows for their extrapolation from data-rich PFAS, such as perfluorooctanoic acid (PFOA), to data-poor ones, facilitating their application in Next Generation Risk Assessment (NGRA). The present study proposes a NG-PBK model for PFOA in humans, parametrized exclusively using in vitro-, and in silico-derived data. The model describes the toxicokinetic processes of 1) partitioning to plasma and tissue proteins, 2) partitioning to cell membrane lipids, 3a) transporter-mediated entero-hepatic circulation and 3b) renal elimination and reabsorption, and 4) elimination via menstruation. Global sensitivity analysis indicated that the model was most sensitive to the fraction unbound in plasma, active-transport parameters, and tissue-plasma partition coefficients. The model was equivalent to already available validated human PFOA-PBK models, while compared to those, it is not calibrated to observed animal, nor human data, illustrating its strength in being mechanistic. The serum concentrations and half-lives predicted by the NG-PBK model were within the ranges of those reported in human volunteer and biomonitoring (HBM) studies, demonstrating the models capacity to accurately predict PFOA toxicokinetics on exposure estimates. Extrapolation of the NG-PBK model to other PFAS, in conjunction with its integration with HBM data, will facilitate the NGRA of PFAS. This is particularly relevant given the paucity of in vivo data for most PFAS, ensuring compliance with the 3R principles.

Background: Type 2 Diabetes Mellitus (T2DM) is a significant public health burden. Emerging evidence links volatile organic compounds (VOCs), such as benzene to endocrine disruption and metabolic dysfunction. However, the effects of chronic environmentally relevant VOC exposures on metabolic health are still emerging. Objective: Building on our previous findings that benzene exposure at smoking levels (50 ppm) induces metabolic impairments in male mice, we investigated the effects of occupationally relevant, below OSHA approved, benzene exposure on metabolic health. Methods: Adult male C57BL/6 mice were exposed to 0.9ppm benzene 8 hours a day for 9 weeks. We assessed measures of metabolic homeostasis and conducted RNA and proteome sequencing on insulin-sensitive organs (liver, skeletal muscle, adipose tissue). Results: This low-dose exposure caused significant metabolic disruptions, including hyperglycemia, hyperinsulinemia, and insulin resistance. Transcriptomic analysis of liver, skeletal muscle, and adipose tissue identified key changes in metabolic and immune pathways especially in liver. Proteomic analysis of the liver revealed mitochondrial dysfunction as a shared feature, with disruptions in oxidative phosphorylation, mitophagy, and immune activation. Comparative analysis with high-dose (50 ppm) exposure showed both conserved and dose-specific transcriptomic changes in liver, particularly in metabolic and immune responses. Conclusions: Our study is the first to comprehensively assess the impacts of occupational benzene exposure on metabolic health, highlighting mitochondrial dysfunction as a central mechanism and the dose-dependent molecular pathways in insulin-sensitive organs driving benzene-induced metabolic imbalance. Our data indicate that current OSHA occupational exposure limits for benzene are insufficient, as they could result in adverse metabolic health in exposed workers, particularly men, following chronic exposure.

STRUCTURED ABSTRACTO_ST_ABSObjectiveC_ST_ABSto explore whether advising environmentally sustainable treatment options in clinical counselling affects patients satisfaction with care compared to less sustainable (standard) options - accounting for differences in severity and types of medical problems. Designa randomised, double-blinded, experimental vignette study with a four (between-group, Type of Advice) x two (between-group, Severity) x five (within-group, Medical Problem) mixed design. Participants received short descriptions of hypothetical patient-physician interactions based on their group allocation and subsequently indicated their satisfaction with care. Settinga general practice or hospital visit. Participantsa representative sample of the general Dutch adult population. Interventionsfour different types of medical advice, varying in level of environmental sustainability and whether sustainability is mentioned explicitly. Main outcome measuressatisfaction with care, operationalised as: treatment acceptability, trust in the physician, trust in the treatment, and the feeling that the physician prioritised their health (Likert scales, 1=strongly disagree, 7=strongly agree). Results1,536 participants completed the study. Across vignettes, participants receiving the less sustainable advice (M=5.6, SD=1.2) were generally more satisfied than participants receiving the more sustainable types of advice (Ps<.001). Participants receiving the explicitly more sustainable advice (M=4.8, SD 1.6) were generally less satisfied than participants receiving the implicitly more sustainable types of advice (Ps<.001). Differences were larger for the high-severity conditions (mean differences 0.4 to 1.8, Ps<.001), non-significant for most low-severity conditions, and varied per medical problem. Conclusionsadvising more sustainable treatment options for high-severity conditions may negatively affect patients satisfaction with care, especially when sustainability is mentioned explicitly. However, the presence and size of the observed effect varied across medical problems and was generally non-significant or small for low-severity conditions. Clinicians situational awareness may differentiate whether sustainability should be discussed, or only guaranteed through institutional level decisions.

Aberrant signal transduction pathways can adversely derail developmental processes. One such process is embryonic eyelid closure that requires MAP3K1. Map3k1 knockout mice have defective eyelid closure and an autosomal recessive eye-open at birth phenotype. In utero exposure to dioxin, a persistent environmental toxicant, causes the same eye defect in Map3k1+/- hemizygous but not wild type pups. Here we explore the mechanisms of Map3k1 (gene) and dioxin (environment) interactions (GxE) in the tissue closure defect. We show that, acting through the AHR, dioxin activates EGFR signaling, which in turn depresses MAP3K1-dependent JNK activity. This effect of dioxin is exacerbated by Map3k1 heterozygosity. Therefore, dioxin exposed Map3k1+/- embryonic eyelids have a marked reduction of JNK activity, accelerated differentiation and impeded polarization in the epithelial cells. Knocking out Ahr or Egfr in eyelid epithelium attenuates the open-eye defects in dioxin-treated Map3k1+/- pups, whereas knockout of Jnk1 and S1pr, encoding the S1P receptors upstream of the MAP3K1-JNK pathway, potentiates dioxin toxicity. Our novel findings suggest that dioxin and genes of the AHR, EGFR and S1P-MAP3K1-JNK pathways constitute a multifactorial mechanism underlying tissue closure abnormalities. Summary statementThe crosstalk between a global environmental pollutant and the pre-existing genetic conditions is mediated through interactive signaling pathways, resulting in anatomical tissue closure abnormalities in development.

Leisure-time physical activity is beneficial for health and is associated with various urban characteristics. Using the exposome framework, the totality of the environment, this study investigated how urban physical environments were associated with leisure-time physical activity during early midlife. A total of 394 participants (mean age: 37, range 34-40) were included from the FinnTwin12 cohort residing in five major Finnish cities in 2020. We comprehensively curated 145 urban physical exposures at residential addresses of participants and measured three leisure-time physical activity measures: (1) total leisure-time physical activity (total LTPA) and its sub-domains (2) leisure-time physical activity without commuting activity (LTPA) and (3) commuting activity. Using K-prototypes cluster analysis, we identified three urban clusters: "original city center," "new city center," and "suburban". Results from adjusted linear regression models showed that participants in the "suburban" cluster had lower levels of total LTPA (beta: -0.13, 95% CI: -0.23, -0.03) and LTPA (beta: -0.17, 95% CI: -0.28, -0.05), compared to those in the "original city center" cluster. The eXtreme Gradient Boosting models ranked exposures related to greenspaces, pocket parks, and road junctions as the top important factors influencing outcomes, and their relationships with outcomes were largely non-linear. More road junctions and more pocket parks correlated with higher total LTPA and LTPA. When the all-year normalized difference vegetation index within a 500 m buffer fell below 0.4, it correlated with higher levels of total LTPA, whereas above 0.4, it correlated with lower levels. To conclude, our findings revealed a positive correlation between urbanicity and physical activity in Finnish cities and decomposed this complexity into crucial determinants. Importance rankings and nonlinear patterns offer valuable insights for future policies and projects targeting physical inactivity.

Human health effects from chronic exposure to mixtures of pesticide residues are little investigated. We compared standard histopathology and serum biochemistry measures and multi-omics analyses in an in vivo subchronic toxicity test of a mixture of six pesticide active ingredients frequently detected in foodstuffs (azoxystrobin, boscalid, chlorpyrifos, glyphosate, imidacloprid and thiabendazole). Sprague-Dawley rats were administered with the pesticide mixture with each ingredient at its regulatory permitted acceptable daily intake. Analysis of water and feed consumption, body weight, histopathology and serum biochemistry showed little or no physiological effects from exposure to the pesticide mixture. In marked contrast, analysis of the host-gut microbiome axis using serum and caecum metabolomics revealed that nicotinamide and tryptophan metabolism were affected, which suggested the initiation of a cell danger response, including adaptation to oxidative stress. Only limited effects were detected on the caecum microbiota by shotgun metagenomics. Further analyses of in vitro bacterial cultures showed that growth of Lactobacillus rhamnosus and Escherichia coli strains was negatively impacted by the pesticide mixture at concentrations that were not inhibitory when exposure was to a single agent. Transcriptomics of the liver showed that 257 genes had their expression changed. Gene functions affected included those involved in the regulation of response to hormones and correlated with previously reported transcriptome changes following administration of nicotinamide. Genome-wide DNA methylation analysis of the same liver samples showed that 4255 CpG sites were differentially methylated (> 10% difference). Overall, we demonstrated that unlike standard blood biochemical and organ histological analysis, in-depth molecular profiling using a combination of high-throughput -omics methods in laboratory animals exposed to low concentrations of pesticides reveals metabolic effects on the gut-liver axis, which can potentially be used as biomarkers for the prediction of future negative health outcomes. Our data suggest that adoption of multi-omics as part of regulatory risk assessment procedures will result in more accurate outcome measures, with positive public health implications.

There is increasing evidence that endocrine disrupting chemicals (EDCs) are contributing to the rise in metabolic disorders and obesity. Humans are constantly exposed to numerous EDCs, thus human exposure entails complex EDC mixtures. In this study, we examined the effects of an EDC mixture, mixture G, composed of four phthalate esters, triclosan, and three poly- och perfluorinated alkyl substances. Mixture G had previously been defined based on its association with lower birth weight in a pregnancy cohort, where low birth weight is an early risk factor for metabolic morbidities later in life. Here, we studied its effects on adipogenesis and uncovered their underlying transcriptional changes. Human mesenchymal stem cells (hMSCs) were exposed to mixture G in concentrations and mixing ratios that reflect those measured in human serum. Mixture G induced adipogenesis in hMSCs, as evidenced by a dose-dependent increase in lipid droplet accumulation after 14-21 days. Notably, significant adipogenic effects were observed at concentrations comparable to those detected in humans. RNA-sequencing upon exposure for 48 h revealed dose-dependent transcriptional changes in over 1000 genes. Mixture G-induced differentially expressed genes (DEGs) showed significant overlap with genes involved in osteogenesis, with glucocorticoid-regulated genes, and with genes associated with birth weight alterations and diabetes type II. These results indicate that exposure to an environmentally relevant EDC mixture induces adipogenesis and leads to transcriptional alterations that might change the balance between adipogenic and osteogenic differentiation as well as the functionality of MSCs, possibly via interference with glucocorticoid signalling. Thus our findings underscore the role of EDCs as metabolic disruptors and shed light on the molecular mechanisms underlying their potential contribution to the development of metabolic disorders. HighlightsO_LIAn endocrine disruptor mixture linked to lower birth weight increases adipogenesis C_LIO_LIThe mixture induced transcriptomic changes at low doses C_LIO_LIAffected genes are associated with birth weight and diabetes type II C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=78 SRC="FIGDIR/small/638050v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@12428bforg.highwire.dtl.DTLVardef@ef28b3org.highwire.dtl.DTLVardef@159024corg.highwire.dtl.DTLVardef@a605b7_HPS_FORMAT_FIGEXP M_FIG C_FIG

Water use (WU) and greenhouse gas emissions (GHGe) are two main issues facing food systems. Still, they have rarely been studied together even though they are potentially conflicting because their levers for improvement are not necessarily the same. Data on food-related environmental pressures suggest that GHGe and WU can be improved jointly, but their potential conflicts and trade-offs have not been explored. This is what we studied here by a compromise programming approach, using multi-criteria non-linear optimization under a set of nutritional and epidemiological constraints. We used food consumption data of adults aged 18-64 years (n=1,456) from the French representative study INCA 3 (2014-2015) coupled with food environmental impact data from the Agribalyse (R) database. A full range of scenarios was identified by prioritizing the two objectives differently, giving weight from 0% to 100%, by 5-% steps, to GHGe improvement over WU improvement. Overall, we showed that it is possible to achieve significant joint reductions in WU and GHGe relative to their observed values: across the prioritization scenarios, WU reduction ranged from -36% to -14% as its prioritization decreased, while GHGe reduction varied less, from -44 to -52% as its prioritization increased. These joint important reductions in GHGe and WU required the removal of meat consumption (beef, pork, poultry and processed meat), while the consumptions of offal and dairy products remained moderate in order to meet nutrient reference values. However, the consumption of some foods varied according to the priority given to WU over GHGe reductions (namely, vegetables, fruit juice, dairy products, eggs, refined cereal, substitutes, offal and potatoes). Fish, whole grains, and fruit remained more constant due to the epidemiological constraints used. Whatever the scenario, the modeled diets were more plant-based than the observed diet from which they differed significantly (only 23-31% of common food consumptions), and were therefore healthier (63-76% reduction in distance to theoretical minimum risk of chronic disease). To conclude, while focusing solely on WU reduction induces a joint GHGe reduction that is near-maximal, the reverse is not true, showing that there is good alignment but also some divergence between these objectives. This suggests that food systems WU should be better considered in dietary guidelines for healthy and sustainable diet.

BackgroundNeurodevelopmental disorders have a strong male bias that is poorly understood. Placenta is a rich source of molecular information about environmental interactions with genetics (including biological sex), that affect the developing brain. We investigated placental-brain transcriptional responses in an established mouse model of prenatal exposure to a human-relevant mixture of polychlorinated biphenyls (PCBs). ResultsTo understand sex, tissue, and dosage effects in embryonic (E18) brain and placenta by RNAseq, we used weighted gene correlation network analysis (WGCNA) to create correlated gene networks that could be compared across sex or tissue. WGCNA revealed that expression within most correlated gene networks was significantly and strongly associated with PCB exposures, but frequently in opposite directions between male-female and placenta-brain comparisons. In both WGCNA and differentially expressed gene analyses, male brain showed more PCB-induced transcriptional changes than male placenta, but the reverse pattern was seen in females. Furthermore, non-monotonic dose responses to PCBs were observed in most gene networks but were most prominent in male brain. The transcriptomic effects of low dose PCB exposure were significantly reversed by dietary folic acid supplementation across both sexes, but these effects were strongest in female placenta. PCB-dysregulated and folic acid-reversed gene networks were commonly enriched in functions in metabolic pathways involved in energy usage and translation, with female-specific protective effects enriched in PPAR, thermogenesis, glycerolipids, and O-glycan biosynthesis, as opposed to toxicant responses in male brain. ConclusionsThe female protective effect in prenatal PCB exposures appears to be mediated by dose-dependent sex differences in transcriptional modulation of metabolism in placenta. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=114 SRC="FIGDIR/small/603326v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@14d4936org.highwire.dtl.DTLVardef@101b87eorg.highwire.dtl.DTLVardef@1f787e6org.highwire.dtl.DTLVardef@1fb1b62_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundAmbient air pollution exposure is associated with structural brain differences and poorer cognition in children; however, mechanisms of toxicity remain unclear. Perivascular spaces (PVS), key for brain waste clearance, may play a role in the neurotoxicity of air pollution. This study explored associations between air pollution exposure, PVS morphology, and cognition in preadolescents. MethodsWe analyzed cross-sectional Adolescent Brain Cognitive DevelopmentSM (ABCD) Study(R) data from 6,949 9-10-year-old participants. Annual average exposures to PM2.5, O3, NO2, and 15 PM2.5 components were estimated using spatiotemporal models mapped to residential addresses. PVS count and volume were derived from T1w and T2w MRI, and cognition was estimated using NIH Toolbox scores. Linear mixed-effects models examined independent associations between air pollution, PVS, and cognition; weighted quantile sum regression assessed co-exposure effects of PM2.5 mixtures. FindingsLinear models revealed that exposures to Zn, NH4 +, and Br were positively associated with PVS count in several regions. Higher PVS count in five key regions was associated with poorer cognitive performance across several NIH Toolbox domains. Higher Ca, Zn, and NH 4 + exposures were associated with poorer cognition (PFDR < 0.01). Higher frontal lobe PVS count mediated the association between Zn exposure and poorer total cognition (P < 0.01). Co-exposure models revealed that PM2.5 mixtures were associated with higher temporal and cingulate PVS count, and poorer working memory and crystallized intelligence (P < 0.01). InterpretationOutdoor air pollution was associated with higher PVS count and reduced cognition, suggesting that brain clearance may be a novel mechanism linking pollution to neurodevelopmental harm in preadolescents. FundingThis work was supported by the National Institutes of Health (NIH) National Institute of Environmental Health Sciences (NIEHS) (Grant Nos. R01ES032295 and R01ES031074 [to MMH]; T32ES013678 [to JM]; P30ES07048 [to JM and MAR]; 3P30ES000002-55S [to MAR]), National Institute of Mental Health (NIMH) (Grant RF1MH123223 [to JC]), National Institute of Neurological Disorders and Stroke (Grant R01NS128486 [to JC]), and EPA grants (Grant Nos. 83587201 and 83544101 [to JS]).