Environmental Exposure Research Articles

Impact of metabolism-disrupting chemicals and folic acid supplementation on liver injury and steatosis in mother-child pairs.

Scarce knowledge about the impact of metabolism-disrupting chemicals (MDCs) on steatotic liver disease limits opportunities for intervention. We evaluated pregnancy MDC-mixture associations with liver outcomes, and effect modification by folic acid (FA) supplementation in mother-child pairs. We studied ∼200 mother-child pairs from the Mexican PROGRESS cohort, with measured 43 MDCs during pregnancy (estimated air pollutants, blood/urine metals or metalloids, urine high- and low-molecular-weight phthalate [HMWPs, LMWPs] and organophosphate-pesticide [OP] metabolites), and serum liver enzymes (ALT, AST) at ∼9 years post-parturition. Outcomes included elevated liver enzymes in children and established clinical scores for steatosis and fibrosis in mothers (i.e. ALT, FLI, HSI, FIB-4). Bayesian Weighted Quantile Sum regression assessed MDC-mixture associations with liver outcomes. We further examined chemical-chemical interactions and effect modification by self-reported FA supplementation. In children, many MDC-mixtures were associated with liver injury. Per quartile HMWP-mixture increase, ALT increased by 10.1% (95%CI: 1.67%, 19.4%) and AST by 5.27% (95% CI: 0.80%, 10.1%). LMWP-mixtures and air pollutant-mixtures were associated with higher AST and ALT, respectively. Air pollutant and non-essential metal/element associations with liver enzymes were attenuated by maternal cobalt blood concentrations (p-interactions<0.05). In mothers, only the LMWP-mixture was associated with odds for steatosis [OR=1.53 (95%CI: 1.01, 2.28) for HSI>36, and OR=1.62 (95%CI: 1.05, 2.49) for AST:ALT<1]. In mothers and children, most associations were attenuated (null) at FA supplementation≥600mcg/day (p-interactions<0.05). Pregnancy MDC exposures may increase risk for liver injury and steatosis, particularly in children. Adequate FA supplementation and maternal cobalt levels may attenuate these associations. The effects of environmental chemical exposures on steatotic liver diseases are not well understood. In a parallel investigation of mothers and children, we found that pregnancy exposures to metabolism-disrupting chemicals may increase the risk for liver injury and steatosis, especially in the child, and that these associations could be attenuated by higher folic acid and/or cobalt levels. These findings can inform policies to decrease environmental chemical pollution and contribute to the design of clinical interventions addressing the MASLD epidemic.

The Effect of Physical Activity on Combined Cadmium, Lead, and Mercury Exposure

Background/Objective: Environmental exposures, such as heavy metals, can significantly affect physical activity, an important determinant of health. This study explores the effect of physical activity on combined exposure to cadmium, lead, and mercury (metals), using data from the 2013–2014 National Health and Nutrition Examination Survey (NHANES). Methods: Physical activity was measured with ActiGraph GT3X+ devices worn continuously for 7 days, while blood samples were analyzed for metal content using inductively coupled plasma mass spectrometry. Descriptive statistics and multivariable linear regression were used to assess the impact of multi-metal exposure on physical activity. Additionally, Bayesian Kernel Machine Regression (BKMR) was applied to explore nonlinear and interactive effects of metal exposures on physical activity. Using a Gaussian process with a radial basis function kernel, BKMR estimates posterior distributions via Markov Chain Monte Carlo (MCMC) sampling, allowing for robust evaluation of individual and combined exposure-response relationships. Posterior Inclusion Probabilities (PIPs) were calculated to quantify the relative importance of each metal. Results: The linear regression analysis revealed positive associations between cadmium and lead exposure and physical activity. BKMR analysis, particularly the PIP, identified lead as the most influential metal in predicting physical activity, followed by cadmium and mercury. These PIP values provide a probabilistic measure of each metal’s importance, offering deeper insights into their relative contributions to the overall exposure effect. The study also uncovered complex relationships between metal exposures and physical activity. In univariate BKMR exposure-response analysis, lead and cadmium generally showed positive associations with physical activity, while mercury exhibited a slightly negative relationship. Bivariate exposure-response analysis further illustrated how the impact of one metal could be influenced by the presence and levels of another, confirming the trends observed in univariate analyses while also demonstrating the complexity varying doses of two metals can have on either increased or decreased physical activity. Additionally, the overall exposure effect analysis across different quantiles revealed that higher levels of combined metal exposures were associated with increased physical activity, though there was greater uncertainty at higher exposure levels as the 95% credible intervals were wider. Conclusions: Overall, this study fills a critical gap by investigating the interactive and combined effects of multiple metals on physical activity. The findings underscore the necessity of using advanced methods such as BKMR to capture the complex dynamics of environmental exposures and their impact on human behavior and health outcomes.

The World Trade Center exposome and health effects in 9/11 rescue and recovery workers

BackgroundIn the aftermath of the World Trade Center (WTC) attack on 11 September 2001, rescue and recovery workers faced hazardous conditions and toxic agents. Prior research linked these exposures to adverse health effects, but mainly examined individual factors, overlooking complex mixture effects.MethodsThis study applies an exposomic approach encompassing the totality of responders’ experience, defined as the WTC exposome. We analyzed data from 34,096 members of the WTC Health Program General Responder, including mental and physical health, occupational history, traumatic and environmental exposures using generalized weighted quantile sum regression.ResultsWe find a statistically significant association between the exposure mixture index and all investigated health outcomes. Factors identified as risk factors include working in an enclosed heavily contaminated area, construction occupation, and exposure to blood and body fluids. Conversely, full-time employment emerged as a protective factor.ConclusionsThis exposomics study emphasizes the importance of considering combined exposures for the identification of harmful and protective factors within the WTC exposome, providing valuable insights for targeted interventions and preventive measures. In an era marked by more frequent and severe natural disasters due to the evolving climate crisis, the exposomic framework is a promising tool for disaster preparedness.

Gut microbiota profiles of patients with idiopathic pulmonary fibrosis.

Purpose/Aim: Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pneumonia. Multiple genetic factors, environmental exposures, micro-aspirations secondary to gastroesophageal reflux, age, sex, smoking habit, and infections contribute to its etiology; consequently, its pathogenesis remains unclear. The homeostasis of gut microbiota, including bacteria, archaea, and fungi, can influence the functions of both the intestine and remote organs. There are still many unknowns regarding the effects and mechanisms of gut microbiota dysbiosis on the development of IPF. In this study, we aimed to characterize the gut microbiota of patients with IPF compared with that of healthy controls. Furthermore, we assessed the effects of antifibrotic drugs on gut dysbiosis. Materials and Methods: This study involved 12 patients with IPF receiving antifibrotic drug therapy, 12 patients with IPF not receiving antifibrotic drug therapy, and 8 healthy controls. The clinical parameters of the patients were recorded, and DNA extracted from stool samples was subjected to 16S ribosomal RNA gene sequencing of the V1-V9 hypervariable regions. Results: Campylobacterota species were detected in the patient groups but not in the control group. Staphylococcales and Gemellaceae species were not detected in the IPF groups; however, a significant relationship was observed in the control group. In the IPF groups, Actinobacteria, Bifidobacteriales, Burkholderiales, Bacteroidaceae, Dorea, Fusicatenibacter, and Ruminococcus -gauvreauii abundance was low and Enterobacterales, Erysipelotrichaceae, Holdemanella, and Alloprevotella abundance was high compared with those in the control group. When the IPF group using antifibrotic drugs and that not using antifibrotic drugs were compared, only Lachnospiraceae UCG 004 abundance was found to be lower in the patient group receiving antifibrotic drugs. Conclusions: Patients with IPF exhibit higher or lower abundance of certain taxa compared to healthy controls, providing novel perspectives on the pathogenesis and treatment of various illnesses. Examining changes in intestinal microbiota during treatment may guide the clinical strategy for managing adverse effects.

Chemical exposomics in biobanked plasma samples and associations with breast cancer risk factors.

The chemical exposome includes exposure to numerous environmental and endogenous molecules, many of which have been linked to reproductive outcomes due to their endocrine-disrupting properties. As several breast cancer risk factors, including age and parity, are related to reproduction, it is imperative to investigate the interplay between such factors and the chemical exposome prior to conducting large scale exposome-basedbreast cancer studies. This pilot study aimed to provide an overview of the chemical exposome in plasma samples from healthy women and identify associations between environmental exposures and three risk factors for breast cancer: age, parity, and age at menarche. Plasma samples (n = 161), were selected based on reproductive history from 100 women participating in the Northern Sweden Health and Disease Study, between 1987 and 2006. Samples were analyzed by liquid chromatography high-resolution mass spectrometry (LC-HRMS) for 77 priority target analytes including contaminants and hormones, with simultaneous untargeted profiling of the chemical exposome and metabolome. Linear mixed effects models were applied to test associations between risk factors and chemical levels. Fifty-five target analytes were detected in at least one individual and over 94,000 untargeted features were detected across all samples. Among untargeted features, 430 could be annotated and were broadly classified as environmental (246), endogenous (167) or ambiguous (17). Applying mixed effect models to features detected in at least 70% of the samples (16,778), we found seven targeted analytes (including caffeine and various per- and poly-fluoroalkyl substances) and 38 untargeted features, positively associated with age. The directionality of these associations reversed for parity, decreasing with increasing births. Seven separate targeted analytes were associated with age at menarche. This study demonstrates how a comprehensive chemical exposome approach can be used to inform future research prioritization regarding associations between known and unknown substances, reproduction, and breast cancer risk. This study illustrates how chemical exposomics of long-term stored blood samples offers valuable insights to discover chemical exposures and their potential links to disease in humans, particularly those related to reproduction and breast cancer risk factors.

Overexpression of BMAL-1 is related to progression of urothelial carcinoma in arsenic exposure area.

Environmental exposure to arsenic has long been associated with various clinical and pathophysiological aspects of urothelial carcinoma (UC), although the role of arsenic in UC and its impact on circadian proteins, particularly BMAL-1, remains unestablished. Previous research suggests that arsenic upregulates Aurora kinase A (AURKA), subsequently inhibiting GSK-3β, which might lead to overexpression of BMAL-1; nevertheless, the underlying pathway and its clinical significance in UC with arsenic exposure have yet to be validated. This study focuses on two potential upstream regulators of BMAL-1, AURKA and GSK-3β. Ninety-nine tumor tissue samples were retrospectively collected along with their respective clinical data. Immunohistochemistry was employed to assess the expression of each protein. A positive relationship was observed between the expression levels of AURKA and BMAL-1 (p < 0.001), while negative correlations were noted between the expression levels of GSK-3β and AURKA (p < 0.001), and between GSK-3β and BMAL-1 (p = 0.003). Tissue samples exposed to arsenic exhibited significantly higher levels of AURKA (p < 0.001) and BMAL-1 (p < 0.001), a markedly lower expression of GSK-3β (p = 0.001), alongside a decreased survival status (p = 0.025) compared to non-exposed samples. Furthermore, patients with UC of higher tumor grade tended to show increased levels of AURKA (p < 0.001), BMAL-1 (p < 0.001), and decreased levels of GSK-3β (p < 0.001). Elevated expression of AURKA (p < 0.001) and BMAL-1 (p = 0.002), as well as reduced expression of GSK-3β (p = 0.003), were also associated with a decreased survival status. This study highlights the differential expression of BMAL-1, AURKA, and GSK-3β in association with arsenic exposure and their significant impact on clinical and pathological features of UC. Moreover, BMAL-1, AURKA, and GSK-3β emerge as potential prognostic markers for UC in regions with arsenic exposure.

Residential Area Characteristics Are Associated With Asthma Burden in Children.

Wheezing illnesses, especially those triggered by rhinovirus infection, cause a major disease burden, and they often precede asthma. Environmental exposures are known to affect recurrence of wheezing. We investigated the relations of population density, greenness (forested areas), and socioeconomic factors of the living surroundings to the burden of asthma in children with prior bronchiolitis. Three hundred and ninety-four children, aged 0-24 months, with doctor-diagnosed bronchiolitis were enrolled in the MARC-30 Finland study. We assessed the children's early-life exposures to greenness and socioeconomic factors using time-series of Corine Land Cover data and Statistics Finland's grid data. We compared the living surroundings data to the prescription drug purchases and special asthma reimbursement benefits until the age 8 years; asthma data were from the Social Insurance Institution of Finland. Children living in sparsely populated areas had lighter asthma disease burden than children living in densely populated ones, with burden measured in median bronchodilator (50DDD [defined daily dose] vs. 104DDD, p = 0.02) and inhaled corticosteroid (0DDD vs. 123DDD, p = 0.04) purchases. In the subgroup of children with rhinovirus-induced bronchiolitis, children living in more forested areas developed asthma 10 months later than those with less forested areas (p = 0.04). Neighborhood socioeconomic characteristics were not associated with differences in asthma burden. Sparsely populated areas and forested environments seem to have a beneficial association with children's respiratory health. These findings warrant further studies on the protective health effects of greenness and the type of biodiversity around homes.

Advances of the exposome at individual levels and prevention in atopic dermatitis.

Atopic dermatitis (AD), or eczema, is an inflammatory skin disease related to environmental factors. As a heterogeneous disease, it presents with complex phenotypes and endotypes. A variety of intrinsic and extrinsic factors can promote the development of AD. While there has been extensive discussion on environmental exposure at the population and community levels, discourse on exposome at individual levels in AD remains insufficient. For example, allergens, microorganisms, parasites, dietary factors, and psychological factors such as stress and anxiety play important roles in AD development. Microorganisms, in particular, exhibit altered composition and diversity on the skin of AD patients, influencing skin barrier integrity and immune responses. The impact of certain microorganisms, such as fungi and viruses, on AD has garnered increasing attention because of their important role in maintaining skin homeostasis. Dietary factors, including sugar intake and histamine-rich foods, may modulate AD risk and severity, although findings are controversial. Allergens, particularly house dust mite allergens, and aeroallergens, exacerbate AD symptoms by promoting inflammation and barrier dysfunction. Since AD is often the first step in the atopic march, its primary prevention measures are crucial. Some preventive measures involving microorganisms, diet, and moisturizers remain controversial. Effective preventive strategies necessitate a clear understanding of the complex mechanisms of AD, especially host-microbe-environment interactions. This review summarizes recent advances in understanding various risk and protective factors, as well as primary prevention measures for AD.

Investigation of nanomaterial and hazardous emissions at coal-fired power stations in Mpumalanga, South Africa

Coal-fired power stations remain the main source of electricity generation in South Africa. The combustion of coal creates fly ash and slag, and increases emissions of particulate matter, which is composed of nano-sized materials. In this study, we investigated nanoparticle emissions from coal-fired power stations. Soil samples were collected at 500 m and 1 km radii from Matla and Kriel power stations. The soil samples were examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray fluorescence (XRF) spectrometry. SEM images confirmed polydisperse particles in the form of semi-spherical, semi-oval, irregular-shaped and amorphous particles in dust and soil samples. The particle size range was 4–150 nm. Carbon sheet–metal oxide composites of As, Zn, Cu, Cr, Ni and V were observed. We found that coal-fired power stations are a potential source of nano-pollution, pointing to elevated human and environmental exposure around such sites. Currently, there are no environmental limits for nanomaterials due to the lack of robust risk assessment; however, this study suggests that coal-fired power stations may be hotspots that could be used as priority cases to examine the environmental implications of nano-pollution.

6PPD, Not 6PPD-Quinone, Induced Serious Zebrafish Eye Damage by Disrupting the Thyroid Signaling Pathway.

N-(1,3-Dimethylbutyl)-N'-phenyl-1,4-phenylenediamine (6PPD) and its oxidation product 6PPD-quinone (6PPDQ) showed different acute toxicities and bioaccumulation potencies in fish. In this study, we compared the thyroid disrupting effects of 6PPD and 6PPDQ through in vitro, in silico, and in vivo assays. Interestingly, although 6PPD and 6PPDQ showed similar docking affinities with thyroid hormone receptor (TR) isoforms and GH3 cell inhibition effects, the thyroid signaling pathway, eye development, phototactic behaviors, and cell density in the retinal layer in the larval zebrafish were significantly affected only following 6PPD exposure. Further investigation demonstrates that 6PPD can act as a TR antagonist to reduce the opsin protein abundance and inhibit the cone photoreceptor cell proliferation, which finally alters the retinal layer structure and causes microphthalmus in zebrafish. Especially, under environmental relevant concentration exposure, 6PPD induced alterations of trβ, opn1lw1, opn1mw1, rpe65a, nr2e3 gene expressions although no significant eye histopathological change was observed. This study illustrates for the first time the more serious visual system impairment of 6PPD compared to 6PPDQ, with thyroid signaling disruption being a contributing factor, while other important toxic targets still require further research.

Asthma and sleep disordered breathing in the pediatric adenotonsillectomy trial for snoring study.

Although asthma is common in children with sleep-disordered breathing (SDB), it is unclear whether and to what extent asthma is associated with SDB-related outcomes. Our objectives are to describe risk factors for asthma among children with mild SDB (mSDB) and assess the association between asthma and the severity of sleep-related outcomes. Cross-sectional analyses were conducted for children aged 3-12.9years with mSDB enrolled in Pediatric Adenotonsillectomy for Snoring Children Study. Sleep-related outcomes included SDB symptoms (Pediatric Sleep Questionnaire-Sleep-Related Breathing Disorder scale(PSQ-SRBD)), SDB-specific quality of life (OSA-18), sleepiness (modified Epworth Sleepiness Score) and polysomnographic and actigraphic measures. Asthma was defined by caregiver-reported diagnosis with current asthma symptoms and medication use, or a Composite Asthma Severity Index (CASI) score ≥ 4. Asthma was further categorized into mild (CASI < 4) and moderate-to-severe (CASI ≥ 4). Regression analyses were conducted to identify asthma risk factors and estimate the associations between mild and moderate-to-severe asthma with sleep-related outcomes. The sample included 425 children (20.3%-Black,17.4%-Hispanic;51.7%-female). The prevalence of asthma was 19.1% (7.1% moderate-to-severe, 12.0% mild). Environmental tobacco smoke exposure and markers of atopy were associated with asthma in multivariable-adjusted analyses. Moderate-to-severe asthma was associated with increased OSA symptoms measured by PSQ-SRBD (adjusted effect estimate for moderate-to-severe vs. no asthma ( adj; 95%CI):0.08;0.01,0.15)) and decreased quality of life measured by OSA-18 ( adj;95%CI:7.5;1.20,13.82)), and a small increase in the arousal index ( adj;95%CI:0.80;0.09,1.51)). Moderate-to-severe asthma was associated with worse QoL and greaterSDB symptoms among children with mSDB. The co-occurrence of common risk factors for mSDB and asthma and worse symptoms and quality of life in children with both conditions support coordinated strategies for prevention and co-management of both disorders. Pediatric Adenotonsillectomy for Snoring (PATS), NCT02562040, https://clinicaltrials.gov/study/NCT02562040.

ANTIMICROBIAL RESISTANCE IN FOODBORNE PATHOGENS: GLOBAL EPIDEMIOLOGICAL INSIGHTS, MECHANISTIC CHALLENGES, AND CUTTING-EDGE DETECTION

Background: Foodborne pathogens’ AMR is considered one of the most significant risks to food safety and human health worldwide.This situation has been worsened by the misuse of antibiotics in livestock farming, making it hard to handle food borne illnesses andhigher rates of sickness and death. Objectives: The main objective of this work is to present a review of the epidemiological data on AMR in foodborne pathogens on a global level, to discuss the genetic and biochemical basis of resistance, and to analyze new approaches to diagnostics and prevention. Methods: The current literature was systematically reviewed to evaluate the incidence and factors related to AMR in these important pathogens; Salmonella spp., Escherichia coli, Campylobacter spp., and Listeria monocytogenes. The study also discusses additional and more sophisticated diagnostic techniques such as CRISPR-based systems, and non-conventional forms of treatment like bacteriophages and antimicrobial peptides. Results: The data indicates that AMR continues to emerge in foodborne pathogens owing to factors such as intensive farming practices and global food trade, and environmental exposure. Some of the advanced diagnostic systems include metagenomics and point-of-care that can quickly and accurately identify the genes that cause resistance. It is, therefore, evident that nontraditional therapies hold promise in containing AMR but they have to be developed to a greater extent. Conclusions: AMR in foodborne pathogens requires a multifaceted approach involving accurate diagnostics, novel therapeutics, and cross-country cooperation. For this reason, there is need to embrace One Health approach to reduce the effect of AMR on health, food and the environment.

Evaluation of Environmental Radiation Exposure and Algorithms for Determining the Occupational Effective Dose During 99mTc-MDP Bone Scintigraphy: A Comprehensive Analysis

This study evaluated the occupational exposure of radiopharmacists, nurses, radiological technologists, and radiological technologist assistants involved in 99mTc-MDP bone scintigraphy procedures. Actual occupational effective doses for individual staff needed ascertaining. An environmental radiation exposure audit revealed all nuclear medicine areas were compliant with ICRP and IAEA guidelines. To ascertain individual doses, they were recorded by OSL badges. The highest exposure was to the radiopharmacists, Hp(0.07) 2.19 µSv during radiolabeling. The nurse administering 99mTc-MDP recorded a dose of 0.27 µSv at Hp(0.07), 26.01% of the total occupational effective dose. The radiological technologist and assistant receive 73.05% of the total effective dose. However, the highest effective dose was received by the technologist assistant positioning patients for SPECT/CT scans, with an effective dose of 32.03 µSv. Single and double dosimetry effective dose estimate algorithms were evaluated, resulting in the double dosimetry being more accurate. The Padovani et al. algorithm was found to most closely align with 99mTc-MDP actual effective dose values (p &gt; 0.05), thereby validating the measurement methods used in this study. The research offers benchmark environmental exposure and effective doses applicable in audits and the continuous effort to enhance radiation safety for personnel during 99mTc-MDP bone scintigraphy.

Association of Combined Effect of Metals Exposure and Behavioral Factors on Depressive Symptoms in Women

This study investigates the combined effects of environmental pollutants (lead, cadmium, total mercury) and behavioral factors (alcohol consumption, smoking) on depressive symptoms in women. Data from the National Health and Nutrition Examination Survey (NHANES) 2017–2018 cycle, specifically exposure levels of heavy metals in blood samples, were used in this study. The analysis of these data included the application of descriptive statistics, linear regression, and Bayesian Kernel Machine Regression (BKMR) to explore associations between environmental exposures, behavioral factors, and depression. The PHQ-9, a well-validated tool that assesses nine items for depressive symptoms, was used to evaluate depression severity over the prior two weeks on a 0–3 scale, with total scores ranging from 0 to 27. Exposure levels of heavy metals were measured in blood samples. BKMR was used to estimate the exposure–response relationship, while posterior inclusion probability (PIP) in BKMR was used to quantify the likelihood that a given exposure was included in the model, reflecting its relative importance in explaining the outcome (depression) within the context of other predictors in the mixture. A descriptive analysis showed mean total levels of lead, cadmium, and total mercury at 1.21 µg/dL, 1.47 µg/L, and 0.80 µg/L, respectively, with a mean PHQ-9 score of 5.94, which corresponds to mild depressive symptoms based on the PHQ-9 scoring. Linear regression indicated positive associations between depression and lead as well as cadmium, while total mercury had a negative association. Alcohol and smoking were also positively associated with depression. These findings were not significant, but limitations in linear regression prompted a BKMR analysis. BKMR posterior inclusion probability (PIP) analysis revealed alcohol and cadmium as significant contributors to depressive symptoms, with cadmium (PIP = 0.447) and alcohol (PIP = 0.565) showing notable effects. Univariate and bivariate analyses revealed lead and total mercury’s strong relationship with depression, with cadmium showing a complex pattern in the bivariate analysis. A cumulative exposure analysis of all metals and behavioral factors concurrently demonstrated that higher quantile levels of combined exposures were associated with an increased risk of depression. Finally, a single variable-effects analysis in BKMR revealed lead, cadmium, and alcohol had a stronger impact on depression. Overall, the study findings suggest that from exposure to lead, cadmium, mercury, alcohol, and smoking, cadmium and alcohol consumption emerge as key contributors to depressive symptoms. These results highlight the need to address both environmental and lifestyle choices in efforts to mitigate depression.

Influence of the combined effect of long hygrothermal aging and thermal cycling on mode I and II interlaminar fracture toughness of carbon/epoxy composites

Carbon fiber/epoxy composites (CFRP) are nowadays extensively used in aircraft structures. During the lifecycle of an aircraft, composites are subjected to temperature and humidity variation over time and that can lead to performance loss. Efforts to understand the environmental conditioning impact on CFRP properties have been widely investigated, leading to the main objective of this study, which was investigating whether damages caused by different environmental conditioning individually are intensified when they are combined. During an aircraft lifetime, several different environmental conditions may occur, and to simulate these effects, this research tested coupons that were exposed to long-term hygrothermal conditioning, drying and thermal cycling and their combined effects on fracture toughness in mode-I and mode-II. Dynamic mechanical and fractographic analysis were also performed on the specimens. Thermal cycling on unaged samples (reference) resulted in average reductions of 5% and 15%, for mode-I and mode-II fracture toughness, respectively, compared to the reference samples. Furthermore, combined effect of thermal cycling and hygrothermal conditionings resulted in reductions around 44% (mode-I) and 15% (mode-II) compared to the reference. The combination of different environmental conditionings was more detrimental to fracture toughness in Mode-I, as confirmed by fractographic analysis. In contrast, Mode-II showed no change in results when exposed to a combination of conditionings, suggesting that isolated analysis of the results can be misinterpreted. Combined effects of thermal cycling and hygrothermal conditioning affected fracture toughness more than either effect alone. Mode-I testing proved to be more sensitive to identifying environmental exposure effects on properties than mode-II.

Environmental Exposure to Per- and Polyfluorylalkyl Substances (PFASs) and Reproductive Outcomes in the General Population: A Systematic Review of Epidemiological Studies

This Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) systematic review synthesized effects of background levels of per- and polyfluorylalkyl substance (PFAS) levels on reproductive health outcomes in the general public: fertility, preterm birth, miscarriage, ovarian health, menstruation, menopause, sperm health, and in utero fetal growth. The inclusion criteria included original research (or primary) studies, human subjects, and investigation of outcomes of interest following non-occupational exposures. It drew from four databases (Web of Science, PubMed, Embase and Health and Environmental Research Online (HERO)) using a standardized search string for all studies published between 1 January 2017 and 13 April 2022. Risk of bias was assessed by two independent reviewers. Data were extracted and reviewed by multiple reviewers. Each study was summarized under its outcome in terms of methodology and results and placed in context, with recommendations for future research. Of 1712 records identified, 30 were eligible, with a total of 27,901 participants (33 datasets, as three studies included multiple outcomes). There was no effect of background levels of PFAS on fertility. There were weakly to moderately increased odds of preterm birth with higher perfluorooctane sulfonic acid (PFOS) levels; the same for miscarriage with perfluorooctanoic acid (PFOA) levels. There was limited yet suggestive evidence for a link between PFAS and early menopause and primary ovarian insufficiency; menstrual cycle characteristics were inconsistent. PFAS moderately increased odds of PCOS- and endometriosis-related infertility, respectively. Sperm motility and DNA health were moderately impaired by multiple PFAS. Fetal growth findings were inconsistent. This review may be used to inform forthcoming drinking water standards and policy initiatives regarding PFAS compounds and drinking water. Future reviews would benefit from more recent studies. Larger studies in these areas are warranted. Future studies should plan large cohorts and open access data availability to capture small effects and serve the public. Funding: Great Lakes Water Authority (Detroit, MI), the Erb Family Foundation through Healthy Urban Waters at Wayne State University (Detroit, MI), and Wayne State University CLEAR Superfund Research (NIH P42ES030991).

Acceleration of acute lung inflammation by IL-1α released through cell death of alveolar macrophages upon phagocytosis of fine Asian sand dust particles

Asian sand dust (ASD), a significant desert sand dust, contains sub-2.5 µm fine particles and adversely affects human health, particularly exacerbating respiratory diseases. Despite this, the intricate physiological responses triggered by inhaled ASD particles remain incompletely understood. This study aimed to comprehensively examine the respiratory effects of ASD, focusing on the spatial distribution of inhaled ASD fine particles within the lungs and the immediate physiological responses they incite. Intratracheal administration of ASD fine particles in mice resulted in efficient phagocytosis by alveolar macrophages (AMs), leading to subsequent neutrophilic inflammation. A subset of ASD-phagocytosed AMs underwent necroptosis, releasing interleukin-1α (IL-1α), causing an increase in chemokines and neutrophils. These responses occurred rapidly within hours of exposure, with endotoxin in ASD particles contributing to the process. Despite variations in desert sand dust composition based on collection locale and timing, this study’s findings provide a foundational basis for understanding the biological effects of desert sand dust. Insights gained into the biological responses to desert sand dust hold promise for developing preventive measures such as air purifiers, and therapeutic agents such as IL-1α neutralizing antibodies, antibacterial agents and cell death inhibitors for human diseases associated with such environmental exposures.

Probing the potential mechanism of permethrin exposure on Alzheimer's disease through enantiomer-specific network toxicology, multi-spectroscopic, and docking approaches

Latest observations indicated that exposure of organic environmental neurotoxins may increase the potential risk of Alzheimer's diseases (AD). As a suspected food-derived risk factor, permethrin, composed of cis-isomer and trans-isomer, is widely used as a broad-spectrum pyrethroid insecticide in agricultural crops for the arthropod pests controlling. Thus, evaluating the impact of permethrin exposure is of great importance to human health. In this study, we performed the toxicological network approach to decipher AD-related mechanisms of cis-permethrin and trans-permethrin. Based on the toxicological network construction and central network topological analysis, human serum albumin (HSA) was selected as the core targets in AD-related developing. From the analysis of the steady state and time-resolved fluorescence quenching of HSA in presence of permethrin mixture, it has been inferred that the nature of the quenching mainly originates from the dynamic modes. Experimentally, the thermodynamic parameters revealed hydrophobic interactions and van der Waals forces played a major role during quenching process. Tryptophan synchronous fluorescence spectra were blue shifted whereas the position of tyrosine synchronous spectra was red shifted during the complex formation. Three-dimensional fluorescence together with FT-IR experiment confirmed that permethrin caused the secondary structure changes in HSA. To better understand the binding patterns between HSA and cis/trans -permethrin, theoretical calculation and molecular docking were implemented. According to the electrostatic potential map, the electrophilic attack region corresponds for electron rich oxygen atoms, while the nucleophilic attack regions were mainly located at over the benzene rings and methyl on cyclopropane ring of permethrins. Docking results shown that cis-permethrin and trans-permethrin located in hydrophobic pocket nearby Domain IIA with the different binding affinity (−7.6 and −9.2 kcal/mol), which consistent with the competitive displacement experiment. All these findings generated in the present study facilitated the elucidation of the molecular mechanism details between permethrin mixture and HSA, which provided fresh insights into the links between environmental exposure and AD-related adverse health outcomes.

Exploring RF-EMF levels in Swiss microenvironments: An evaluation of environmental and auto-induced downlink and uplink exposure in the era of 5G

The advancement of cellular networks requires updating measurement protocols to better study radiofrequency electromagnetic field (RF-EMF) exposure emitted from devices and base stations. This paper aims to present a novel activity-based microenvironmental survey protocol to measure environmental, auto-induced downlink (DL), and uplink (UL) RF-EMF exposure in the era of 5G. We present results when applying the protocol in Switzerland.Five study areas with different degrees of urbanization were selected, in which microenvironments were defined to assess RF-EMF exposure in the population. Three scenarios of data transmission were performed using a user equipment in flight mode (non-user), inducing DL traffic (max DL), or UL traffic (max UL). The exposimeter ExpoM-RF 4, continuously measuring 35 frequency bands ranging from broadcasting to Wi-Fi sources, was carried in a backpack and placed 30cm apart from the user equipment.The highest median RF-EMF levels during the non-user scenario were measured in an urban business area (1.02 mW/m2). Here, DL and broadcasting bands contributed the most to total RF-EMF levels. Compared to the non-user scenario, exposure levels increased substantially during max DL due to the 5G band at 3.5 GHz with 50% of the median levels between 3.20-12.13 mW/m2, mostly in urban areas. Note that the time-division nature of this band prevents distinguishing between exposure contribution from DL beamforming or UL signals emitted at this frequency. The highest levels were measured during max UL, especially in rural microenvironments, with 50% of the median levels between 12.08-37.50 mW/m2. Mobile UL 2.1 GHz band was the primary contributor to exposure during this scenario.The protocol was successfully applied in Switzerland and used in nine additional countries. Inducing DL and UL traffic resulted in a substantial increase in exposure, whereas environmental exposure levels remained similar to previous studies. This data is important for epidemiological research and risk communication/management.

A physiologically based toxicokinetic model for microplastics and nanoplastics in mice after oral exposure and its implications for human dietary exposure assessment

Evidence of microplastics (MPs) and nanoplastics (NPs) in foods and daily-use products, along with their frequent detection in the human body, has raised concerns regarding their potential impact on human health through dietary ingestion. However, there is a lack of quantitative tools to simulate their bioaccumulation and tissue distribution following environmental exposure. To address this gap, we developed the first physiologically based toxicokinetic (PBTK) model for predicting the biodistribution of MPs and NPs in mice following oral exposure under various exposure scenarios. This novel model incorporated key kinetic mass transport processes, such as membrane permeability, albumin binding, and cellular uptake. We identified that the absorption rate in the gastrointestinal tract and fecal excretion rate constant had significant impacts on organ dosimetry. Our regression analysis indicated that the size-dependent dissociation constant and urine clearance rate constant sharply increased by a factor of 3 as NPs particle size increased to 1µm. Finally, we developed a graphical user interface to enable interactive visualization and analysis for future applications, supporting human dietary exposure and risk assessment using available food consumption data and MPs/NPs residue data. The simulation results offer a mechanistic perspective, enhancing understanding of the internal organ dosimetry burden and health impacts from dietary exposure to MPs and NPs.