Target Exposome for Characterizing Early Gestational Exposure to Contaminants of Emerging Concern and Association with Gestational Diabetes Mellitus

An Enhanced Protocol to Expand Human Exposome and Machine Learning-Based Prediction for Methodology Application

The human exposome remains limited due to the challenging analytical strategies used to reveal low-level endocrine-disrupting chemicals (EDCs) and their metabolites in serum and urine. This limits the integrity of the EDC exposure assessment and hinders understanding of their cumulative health effects. In this study, we propose an enhanced protocol based on multi-solid-phase extraction (multi-SPE) to expand human exposome with polar EDCs and metabolites and train a machine learning (ML) model for methodology prediction based on molecular descriptors. The protocol enhanced the measurement of 70 (25%) and 34 (12%) out of 295 well-acknowledged EDCs in serum and urine compared to the hydrophilic-lipophilic balance sorbent alone. In a nontarget analysis of serum and urine from 20 women of childbearing age in a cohort of 498, controlling occupational factors and daily behaviors for high chemical exposure potential, the multi-SPE protocol increased the measurement of 10 (40%) and 16 (53%) target EDCs and identification of 17 (77%) and 70 (36%) nontarget chemicals (confidence ≥ level 3) in serum and urine, respectively. Interestingly, the ML model predicted that the multi-SPE protocol could identify an additional 38% of the most bioactive chemicals. In conclusion, the multi-SPE protocol advances human exposome by expanding the measurement and identification of exposure profiles.

Per- and Polyfluoroalkyl Substances and Female Health Concern: Gender-based Accumulation Differences, Adverse Outcomes, and Mechanisms

The deleterious health implications of perfluoroalkyl and polyfluoroalkyl substances (PFAS) are widely recognized. Females, in contrast to males, exhibit unique pathways for PFAS exposure and excretion, leading to complex health outcomes. The health status of females is largely influenced by hormone-related processes. PFAS have been reported to be associated with various aspects of female health, including reproductive system disorders and pregnancy-related diseases. In this article, we provide insights into the correlations between PFAS and female-prevalent diseases. Current epidemiological and toxicological evidence has demonstrated that the adverse effects of PFAS on the health of the female reproductive system are primarily attributed to the disruption of the hypothalamic-pituitary-gonadal (HPG) axis and hormonal homeostasis. However, these findings do not sufficiently elucidate the intricate associations between PFAS and specific diseases. Furthermore, autoimmune disorders, another category that is more prevalent in women compared to men, require additional investigation. Immune biomarkers pertinent to autoimmune disorders have been observed to be influenced by PFAS exposure, although epidemiological evidence is insufficient to substantiate these relations. Further thorough exploration encompassing epidemiological and toxicological studies is essential to elucidating the inherent influence of PFAS on human pathologies. Additionally, comprehensive investigations into female health issues beyond their reproductive functions is essential.

Per- and Polyfluoroalkyl Substances in Semen Associated with Repeated Measures of Semen Quality in Healthy Adult Men

Although epidemiological studies have explored the association between poly- and perfluoroalkyl substances (PFAS) concentrations and semen quality, existing findings are often inconsistent. Our work aimed to explore the association of PFAS in plasma and semen with repeated measures of semen quality parameters in healthy adults. Plasma was collected at the initial recruitment and semen was collected at least once within five predetermined intervals during an approximately 3-month period. Semen volume, concentration, motility, and total sperm count were measured in each semen specimen. PFAS was measured in individual plasma samples (n = 1252) and pooled semen samples (n = 1019) from multiple collections (or in a single semen sample if no multiple collection was available). The results reveal seminal perfluorooctanoic acid, perfluorooctanesulfonic acid, perfluorohexanesulfonic acid, and 6:2 chlorinated polyfluoroalkyl ether sulfonate were significantly associated with decreased sperm progressive motility and total motility, while multiple seminal PFAS were positively associated with sperm concentration and total sperm count. By contrast, null associations were observed between plasma PFAS and semen quality. Our study provides epidemiological evidence that PFAS exposure may affect male fertility and seminal PFAS should be measured for precise assessment of the impact of PFAS on male reproductive performances.

Comprehensive analysis of transplacental transfer of environmental pollutants detected in paired maternal and cord serums

Prenatal exposure to hazardous environmental pollutants is a critical global concern due to their confirmed presence in umbilical cord blood, indicating the ability of pollutants to cross the placental barrier and expose the fetus to harmful compounds. However, the transplacental transfer efficiencies (TTEs) of many pollutants remain underexplored. Herein, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantitatively analyze 91 environmental pollutants, including 13 bisphenols (BPs), 18 organophosphorus flame retardants (OPFRs), 7 brominated and other flame retardants (BFRs), 34 phthalates (PAEs), and 19 per- and polyfluoroalkyl substances (PFASs), in paired maternal and cord serums. 38 pollutants were detected in serums, including 5 BPs, 13 OPFRs, 2 BFRs, 4 PAEs, and 14 PFASs. Among the detected pollutants, bisphenol A (BPA) exists in the highest concentration (GM: 10.92 ng/mL in maternal serums and 12.66 ng/mL in cord serums), followed by tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), perfluorooctanoic acid (PFOA), and 4,4'-(1,3-phenylenediisopropylidene) bisphenol (BPM). The exposure concentrations of the same type of pollutants were highly correlated between maternal and cord serums. Perfluorohexanoic acid (PFHxA) had the highest TTE value (5.526), while perfluorooctane sulfonic acid (PFOS) had the lowest (0.206). TTEs of PFOS and perfluorononanoic acid (PFNA) were higher for female newborns, whereas TTEs of perfluorohexadecanoic acid (PFHxDA) and perfluorodecane sulfonic acid (PFDS) were higher for male newborns. Moreover, the expression levels of the transplacental transporters ABCA1, ABCC2, ABCC3, ABCC4, ABCG1, SLCO3A1, and SLC22A3 were associated with the transplacental transfer of triphenyl phosphate (TPHP), TDCIPP, di-n-propyl phthalate (DPRP), perfluoroundecanoic acid (PFUnDA), perfluorotridecanoic acid (PFTrDA), and PFOS. Further research is essential to unveil the mechanisms involved in the transplacental transfer of environmental pollutants, ultimately boosting our comprehension of their impact on fetal health and birth outcomes.

Comprehensive and Sensitive Analysis of Total PAEs Using a Label-Free Zero-Voltage Photoelectrochemical Biosensor

The sensing of phthalate esters (PAEs) is vital for people's health and environmental protection. This study aimed to develop a highly sensitive and selective photoelectrochemical (PEC) biosensor for PAEs analysis in complex samples. The biosensor is based on a CdS nanoparticle/TiO2 nanotube (CdS NP/TiO2 NT) electrode substrate and a truncated PAEs aptamer (PAEs-apt). By exploiting spatial variations in the potential resistance of the sensing interface, the biosensor achieved superior sensitivity in determining the concentration of PAEs compared to the SELEX aptamer. It exhibited a linear correlation in the range of 0.005 to 1 ng/mL with a detection limit of 1.67 ng/L. Furthermore, the biosensor displayed excellent selectivity for PAEs, with an analysis error factor below 0.277 when the concentration of interfering species was 100 times that of the target. The high performance of the biosensor was attributed to the excellent photoelectronic properties of CdS NPs/TiO2 NTs, high density of PAEs-apt for PAEs, high affinity of PAEs-apt for PAEs, and specific recognition of PAEs. Notably, this PEC biosensor could be used for the PAEs assay in urine and water samples, providing a sensitive and simple analytical method for detecting the same class of compounds with similar chemical structures in complex samples.

Use, limitations, and future directions of mixtures approaches to understand the health impacts of weather- and climate change-related exposures, an under-studied aspect of the exposome

The exposome concept aims to account for the comprehensive and cumulative effects of physical, chemical, biological, and psychosocial influences on biological systems. To date, limited exposome research has explicitly included climate change-related exposures. We define these exposures as those that will intensify with climate change, including direct effects like extreme heat, tropical cyclones, wildfires, downstream effects like air pollution, power outages, and limited or contaminated food and water supplies. These climate change-related exposures can occur individually or simultaneously. Here, we discuss the concept of a climate mixture, defined as three or more simultaneous climate change-related exposures, in the context of the exposome. In a motivating climate mixture example, we consider the impact of a co-occurring tropical cyclone, power outage, and flooding on respiratory hospitalizations. We identify current gaps and future directions for assessing the effect of climate mixtures on health. Mixtures methods allow us to incorporate climate mixtures into exposomics.

Identification of Primary Organophosphate Esters Contributing to Enhanced Risk of Gestational Diabetes Mellitus Based on a Case-Control Study

Epidemiological studies on associations of organophosphate ester (OPE) exposure and gestational diabetes mellitus (GDM) risk, which remain rare and inconclusive, were carried out with a case-control population comprising 287 GDM and 313 non-GDM pregnant women recruited from Tianjin. The GDM group suffered distinctly higher serum concentrations of tri-n-butyl phosphate (TNBP), tri(2-butoxyethyl) phosphate (TBOEP), triphenyl phosphate (TPHP), tri-iso-propyl phosphate (TIPP), and tri(1-chloro-2-propyl) phosphate (TCIPP) than the healthy control group (p < 0.001). Traditional analysis methods employed for either individual or mixture effects found positive correlations (p < 0.05) between the concentrations of five OPEs (i.e., TNBP, TBOEP, TPHP, TIPP, and TCIPP) and the incidence of GDM, while 2-ethylhexyl diphenyl phosphate, tri(1-chloro-2-propyl) phosphate, and bis(2-ethylhexyl) phosphate exhibited opposite effects. Three machine learning methods considering the concurrence of OPE mixture exposure and population characteristics were applied to clarify their relative importance to GDM risk, among which random forest performed the best. Several OPEs, particularly TNBP and TBOEP ranking at the top, made greater contributions than some demographical characteristics, such as prepregnancy body mass index and family history of diabetes, to the occurrence of GDM. This was further validated by another independent case-control population obtained from Hangzhou.

Spatiotemporal distribution and transport flux of organophosphate esters in the sediment of the Yangtze River

The Yangtze River Basin is an important area for organophosphate esters (OPEs) consumption and emission. Studies proved high OPE detection in Yangtze River water, but there is limited information about the spatiotemporal distribution and transport flux of OPEs in sediment. The present study investigated 16 OPEs in sediment from upstream to mid-downstream of the Yangtze River. The mean concentration of OPEs was 84.30 ng/g, and alkyl-OPEs was the primary component. Great specific surface area and high content of organic carbon significantly increased OPE concentration in Three Gorges Reservoir (TGR) by physical adsorption and chemical bonds (p < 0.05), making TGR the most contaminated area in mainstream. No significant differences in OPE constituents were found in seasonal distribution. Four potential sources of OPEs were identified by principal component analysis and self-organizing maps, and traffic emissions were the dominant source for OPEs. The hazard quotient model results indicated that aryl-OPEs showed moderate risks in the mainstream of Yangtze River, alkyl-OPEs and Cl-OPEs showed low risks. TGR was a significant sink of OPEs in Yangtze River and buried 7.41 tons of OPEs in 2020, a total of 14.87 tons of OPE were transported into the sea by sediment.

A critical review on organophosphate esters in drinking water: Analysis, occurrence, sources, and human health risk assessment

Organophosphate esters (OPEs) are ubiquitous in the environment. Copious studies assessed OPEs in various environmental media. However, there is limited summative information about OPEs in drinking water. This review provides comprehensive data for the analytical methods, occurrence, sources, and risk assessment of OPEs in drinking water. In general, liquid-liquid extraction and solid-phase extraction are the most common methods in the extraction of OPEs from drinking water, while gas chromatography and liquid chromatography are the most commonly used instrumental methods for detecting OPEs in drinking water. On the basis of these techniques, a variety of methods on OPEs pretreatment and determination have been developed to know the pollution situation of OPEs. Studies on the occurrence of OPEs in drinking water show that the total concentrations of OPEs vary seasonally and regionally, with tris(1-chloro-2-isopropyl) phosphate and tris(2-chloroethyl) phosphate dominant among different kinds of drinking water. Source identification studies show that there are three main sources of OPEs in drinking water: 1) source water contamination; 2) residual in drinking water treatment process; 3) leakage from device or pipeline. Besides, risk assessments indicate that individual and total OPEs pose no or negligible health risk to human, but this result may be significantly underestimated. Finally, the current knowledge gaps on the research of OPEs in drinking water are discussed and some suggestions are provided for future environmental research.