Effects and Mechanisms of Phthalates' Action on Reproductive Processes and Reproductive Health: A Literature Review

Assessment of maternal phthalate exposure in urine across three trimesters and at delivery (umbilical cord blood and placenta) and its influence on birth anthropometric measures

Phthalates, commonly used in plastic manufacturing, have been linked to adverse reproductive effects. Our research from the Saudi Early Autism and Environment Study (2019-2022), involving 672 participants, focused on the impacts of maternal phthalate exposure on birth anthropometric measures. We measured urinary phthalate metabolites in 390 maternal samples collected during each of the three trimesters of pregnancy and in cord serum and placental samples obtained at delivery. We employed various statistical methods to analyze our data. Intraclass correlation coefficients were used to assess the consistency of phthalate measurements, generalized estimating equations were used to explore temporal variations across the trimesters, and linear regression models, adjusted for significant confounders and Bonferroni correction, were used for each birth outcome. Exposure to six phthalates was consistently high across trimesters, with 82 %-100 % of samples containing significant levels of all metabolites, except for mono-benzyl phthalate. We found a 3.15 %-3.73 % reduction in birth weight (BWT), 1.39 %-1.69 % reduction in head circumference (HC), and 3.63 %-5.45 % reduction in placental weight (PWT) associated with a one-unit increase in certain urinary di(2-ethylhexyl) phthalate (DEHP) metabolites during the first trimester. In the second trimester, exposure to MEP, ∑7PAE, and ∑LMW correlated with a 3.15 %-4.5 % increase in the APGAR 5-min score and increases in PWT by 8.98 % for ∑7PAE and 9.09 % for ∑LMW. Our study also highlighted the maternal-to-fetal transfer of DEHP metabolites, indicating diverse impacts on birth outcomes and potential effects on developmental processes. Our study further confirmed the transfer of DEHP metabolites from mothers to fetuses, evidenced by variable rates in the placenta and cord serum, with an inverse relationship suggesting a passive transfer mechanism. Additionally, we observed distinct phthalate profiles across these matrices, adversely impacting birth outcomes. In serum, we noticed increases associated with DEHP metabolites, with birth gestational age rising by 1.01 % to 1.11 %, HC by 2.84 % to 3.67 %, and APGAR 5-min scores by 3.77 % to 3.87 %. Conversely, placental analysis revealed a different impact: BWT decreased by 3.54 % to 4.69 %, HC reductions ranged from 2.57 % to 4.69 %, and chest circumference decreased by 7.13 %. However, the cephalization index increased by 3.67 %-5.87 %. These results highlight the complex effects of phthalates on fetal development, indicating their potential influence on crucial developmental processes like sexual maturation and brain development.

Antioxidant vitamins' modification of the adverse health effects induced by phthalate exposure: A scoping review of epidemiological and experimental studies

The exposure to and health hazards of phthalates have received abundant attention. However, reducing phthalate exposure and further decreasing the associated health risks are difficult. Nonetheless, it is important to actively seek relevant measures. Recently, antioxidant vitamins have been frequently mentioned to improve phthalate-related issues. This scoping review summarizes the existing epidemiological and experimental studies on the interaction of phthalates with antioxidant vitamins. Through a systematic search, sparse epidemiological studies explored the effects of interaction between phthalates and vitamins on reproduction, the endocrine, respiratory, and nervous system and human aging. Four prospective studies were conducted in China, the United States, Canada and Netherlands. Only one study from Netherlands focused on the female reproductive system.The other three studies focused on neurological damage to fetuses caused by phthalate exposure, and its mitigation by vitamin supplementation during pregnancy. Four cross-sectional studies were conducted based on the United States National Health and Nutrition Examination Survey database. These studies involved hazards in different systems and interactions with different vitamins. Overall, epidemiological evidence suggests that antioxidant vitamins such as vitamin A, B, D, and folic acid probably may alter the health hazards induced by phthalate exposure. Current animal studies often focus on three phthalates, DBP, DEHP and DIDP,2 and most commonly, the first two phthalates. These chemicals cause reproductive, urinary, digestive and neurodevelopmental damage; the antioxidant vitamin C, E and B could mitigate the harm caused by phthalates. Possible mechanisms involve reducing oxidative stress, removing methylation,etc. Determining whether these mechanisms are similar to those in humans requires a rigorous experimental study.

Oxidative stress as a potential mechanism linking gestational phthalates exposure to cognitive development in infancy

BACKGROUND

Gestational exposure to phthalates, endocrine disrupting chemicals widely used in consumer products, has been associated with poor recognition memory in infancy. Oxidative stress may represent one pathway linking this association. Hence, we examined whether exposure to phthalates was associated with elevated oxidative stress during pregnancy, and whether oxidative stress mediates the relationship between phthalate exposure and recognition memory.

METHODS

Our analysis included a subset of mother-child pairs enrolled in the Illinois Kids Development Study (IKIDS, N = 225, recruitment years 2013-2018). Concentrations of 12 phthalate metabolites were quantified in 2nd trimester urine samples. Four oxidative stress biomarkers (8-isoprostane-PGF2α, 2,3-dinor-5,6-dihydro-8-isoPGF2α, 2,3-dinor-8-isoPGF2α, and prostaglandin-F2α) were measured in 2nd and 3rd trimester urine. Recognition memory was evaluated at 7.5 months, with looking times to familiar and novel stimuli recorded via infrared eye-tracking. Novelty preference (proportion of time looking at a novel stimulus when paired with a familiar one) was considered a measure of recognition memory. Linear mixed effect models were used to estimate associations between monoethyl phthalate (MEP), sum of di(2-ethylhexyl) phthalate metabolites (ΣDEHP), sum of di(isononyl) phthalate metabolites (ΣDINP), and sum of anti-androgenic phthalate metabolites (ΣAA) and oxidative stress biomarkers. Mediation analysis was performed to assess whether oxidative stress biomarkers mediated the effect of gestational phthalate exposure on novelty preference.

RESULTS

The average maternal age at delivery was 31 years and approximately 50 % of participants had a graduate degree. A natural log unit increase in ΣAA, ΣDINP, and ΣDEHP was associated with a statistically significant increase in 8-isoPGF2α, 2,3-dinor-5,6-dihydro-8-isoPGF2α, and 2,3-dinor-8-isoPGF2α. The association was greatest in magnitude for ΣAA and 2,3-dinor-5,6-dihydro-8-isoPGF2α (β = 0.45, 95 % confidence interval = 0.14, 0.76). The relationship between ΣAA, ΣDINP, ΣDEHP, and novelty preference was partially mediated by 2,3-dinor-8-isoPGF2α.

CONCLUSIONS

Gestational exposure to some phthalates is positively associated with oxidative stress biomarkers, highlighting one mechanistic pathway through which these chemicals may impair early cognitive development.

Urinary concentrations of phthalate and phthalate alternative metabolites and sperm DNA methylation: A multi-cohort and meta-analysis of men in preconception studies

Phthalates are ubiquitous pollutants in the environment; however, the mechanisms of phthalate-associated reproductive disorders in men are not fully understood. The aim of this study is to investigate associations between urinary phthalate metabolite concentrations and sperm DNA methylation. The study was conducted on 697 men from three prospective pregnancy cohorts: Longitudinal Investigation of Fertility and the Environment (LIFE) Study, Sperm Environmental Epigenetics and Development Study (SEEDS), and Environment and Reproductive Health (EARTH) Study. Eighteen phthalate and two phthalate alternative metabolites were quantified by mass spectrometry in preconception urinary samples and sperm DNA methylation was measured via Illumina EPIC Array (v1). Regional methylation analyses were conducted to identify cohort-specific loci associated with urinary phthalate metabolites. Models were adjusted for age, body mass index (BMI), race, smoking status, urinary creatinine/specific gravity, and analytical batch for phthalate measurements. The cohort-specific results were meta-analyzed using METAL. Participants had an average age of 30 years, most (79.6 %) of whom had BMI>25 kg/m2 and were non-smokers (90.1 %). A total of 7,979 differentially methylated regions (DMRs; 7,979 LIFE-specific DMRs, 72 SEEDS-specific DMRs, and 23 EARTH-specific DMRs) were associated with urinary MBzP, MiBP, MMP, MCNP, MCPP, MBP, and MCOCH. Meta-analysis identified fewer DMRs than cohort-specific models: 946 DMRs were associated with MBzP, 27 DMRs associated with MiBP, and 1 DMR associated with MEHP. The majority of cohort-specific and meta-analysis-derived DMRs displayed a positive association with phthalate metabolite concentrations and were enriched in genes associated with spermatogenesis, response to hormones and their metabolism, embryonic organ development and developmental growth. In conclusion, several preconception urinary phthalate metabolites were associated with increased DNA methylation patterns in sperm. These findings provide an epigenetic pathway by which environmental phthalate exposures can impact couples' reproductive outcomes.

Male Fertility as a Proxy for Health

Male fertility is affected by a wide range of medical conditions that directly and indirectly affect spermatogenesis. As such, it can be useful as both an indicator of current health and a predictive factor for future health outcomes. Herein, we discuss the current literature regarding the association between male fertility and systemic health conditions and exposures. We review the connection between male fertility and genetics, medications, diet, and environmental pollutants, as well as its effects on future oncologic, cardiovascular, and autoimmune conditions. Understanding this interplay will allow more health care providers to engage in health counseling that will not only improve men's reproductive outcomes but also their overall health.

The Effect of Various Environmental Pollutants on the Reproductive Health in Children: A Brief Review of the Literature

PURPOSE OF REVIEW

Environmental pollutants in air, water, soil, and food are a significant concern due to their potential adverse effects on fetuses, newborns, babies, and children. These chemicals, which pass to fetuses and babies through trans-placental transfer, breast milk, infant formula, dermal transfer, and non-nutritive ingestion, can cause health problems during childhood. This review aims to discuss how exposure to various environmental pollutants in early life stages can disrupt reproductive health in children.

RECENT FINDINGS

Environmental pollutants can affect Leydig cell proliferation and differentiation, decreasing testosterone production throughout life. This may result in cryptorchidism, hypospadias, impaired semen parameters, and reduced fertility. Although many studies on female reproductive health cannot be interpreted to support causal relationships, exposure to pollutants during critical windows may subsequently induce female reproductive diseases, including early or delayed puberty, polycystic ovary syndrome, endometriosis, and cancers. There is growing evidence that fetal and early-life exposure to environmental pollutants could affect reproductive health in childhood. Although diet is thought to be the primary route by which humans are exposed to various pollutants, there are no adopted nutritional interventions to reduce the harmful effects of pollutants on children's health. Therefore, understanding the impact of environmental contaminants on various health outcomes may inform the design of future human nutritional studies.

Ketoconazole blocks progesterone production without affecting other parameters of cumulus-oocyte complex maturation

Ketoconazole (KTZ) is widely used as a fungicide, but it is also known to target steroid hormone formation which may affect female reproductive health. Our study aims to investigate the effects of KTZ on in vitro matured bovine cumulus-oocyte complexes (COCs), as a model for female reproductive toxicity. Cumulus cells of in vitro maturing COCs produce progesterone and pregnenolone, but exposure to 10-6 M KTZ effectively blocked the synthesis of these hormones. Exposure to lower concentrations of KTZ (i.e. 10-7 M and 10-8 M) had no such effect on steroidogenesis compared to the 0.1 % v/v DMSO vehicle control. Classical parameters of in vitro COC maturation, such as oocyte nuclear maturation to the metaphase II stage and expansion of the cumulus investment, were not affected by any KTZ concentration tested. Apoptosis and necrosis levels were also not altered in cumulus cells or oocytes exposed to KTZ. Moreover, oocytes exposed to KTZ during maturation showed normal cleavage and early embryo development up to day 8 post fertilization; albeit a statistically significant decrease was observed in day 8 blastocysts produced from oocytes exposed to the lowest concentration of 10-8 M KTZ. When unexposed mature oocytes were fertilized, followed by embryo culture for 8 days under KTZ exposure, no adverse effects in embryo cleavage and blastocyst formation were observed. In conclusion, KTZ has no major impact on in vitro bovine oocyte maturation and blastocyst formation in our study, even at concentrations blocking steroidogenesis.

Mixtures of phthalates disrupt expression of genes related to lipid metabolism and peroxisome proliferator-activated receptor signaling in mouse granulosa cells

Phthalates are a class of known endocrine disrupting chemicals that are found in common everyday products. Several studies associate phthalate exposure with detrimental effects on ovarian function, including growth and development of the follicle and production of steroid hormones. We hypothesized that dysregulation of the ovary by phthalates may be mediated by phthalate toxicity towards granulosa cells, a major cell type in ovarian follicles responsible for key steps of hormone production and nourishing the developing oocyte. To test the hypothesis that phthalates target granulosa cells, we harvested granulosa cells from adult CD-1 mouse ovaries and cultured them for 96 hours in vehicle control, a phthalate mixture, or a phthalate metabolite mixture (0.1-100 μg/mL). After culture, we measured metabolism of the phthalate mixture into monoester metabolites by the granulosa cells, finding that granulosa cells do not significantly contribute to ovarian metabolism of phthalates. Immunohistochemistry of phthalate metabolizing enzymes in whole ovaries confirmed that these enzymes are not strongly expressed in granulosa cells of antral follicles and that ovarian metabolism of phthalates likely occurs primarily in the stroma. RNA sequencing of treated granulosa cells identified 407 differentially expressed genes, with overrepresentation of genes from lipid metabolic processes, cholesterol metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. Expression of significantly differentially expressed genes related to these pathways was confirmed using qPCR. Our results agree with previous findings that phthalates and phthalate metabolites have different effects on the ovary, but both interfere with PPAR signaling in granulosa cells.

Protective effect of rutin on acrylamide induced ovarian inflammation, oxidative stress, DNA damage, and hormonal changes: Based on in silico and in vivo study

Acrylamide (AA) is a carcinogenic compound that affects people due to its frequent use in laboratories and industry as well as the high-temperature cooking of foods with high hydrocarbon content. AA is known to cause severe reproductive abnormalities. The main aim of this study is to evaluate the protective effect of rutin (RU), a phytoactive compound, against AA-induced reproductive toxicity in female rats. Initially, rats were exposed to AA (40 mg/kg for 10 days). Therapy of RU was given after AA intoxication consecutively for 3 days. After 24 h of the last treatment, all the animals were sacrificed. The study evaluated reproductive hormones, oxidative stress markers, membrane-bound enzymes, DNA damage, histological findings, and an in silico approach to determine the protective efficacy of RU. The results indicated that RU significantly protected against inflammation, oxidative stress, and DNA damage induced by AA, likely due to its antioxidant properties.

Detrimental consequences of micropolymers associated plasticizers on endocrinal disruption

The prevalence of polymer usage in everyday activities has emerged as a detriment to both human life and the environment. A large number of studies describe severe impacts of micropolymers (MP) and nanopolymers (NP) on various organ systems, including the endocrine system. Additionally, plasticizers utilized as additives have been identified as endocrine-disrupting chemicals (EDCs). MP/NP, along with associated plasticizers, affect principal signalling pathways of endocrine glands such as the pituitary, thyroid, adrenal, and gonads, thereby disrupting hormone function and metabolic processes crucial for maintaining homeostasis, fertility, neural development, and fetal growth. This review delves into the sources, distribution, and effects of micropolymers, nanopolymers, and associated plasticizers acting as EDCs. Furthermore, it provides a detailed review of the mechanisms underlying endocrine disruption in relation to different types of MP/NP.

The dose disrupts the pathway: application of Paracelsus principle to mechanistic toxicology

Arguably the most famous principle of toxicology is "The dose makes the poison" formulated by Paracelsus in the 16th century. Application of the Paracelsus's principle to mechanistic toxicology may be challenging as one compound may affect many molecular pathways at different doses with different and often nonlinear dose-response relationships. As a result, many mechanistic studies of environmental and occupational compounds use high doses of xenobiotics motivated by the need to see a clear signal indicating disruption of a particular molecular pathway. This approach ignores the possibility that the same xenobiotic may affect different molecular mechanism(s) at much lower doses relevant to human exposures. To amend mechanistic toxicology with a simple and concise guiding principle, I suggest recontextualization of Paracelsus's following its letter and spirit: "The dose disrupts the pathway". Justification of this statement includes observations that many environmental and occupational xenobiotics affect a broad range of molecular cascades, that most molecular pathways are sensitive to chemical exposures, and that different molecular pathways are sensitive to different doses of a chemical compound. I suggest that this statement may become a useful guidance and educational tool in a range of toxicological applications, including experimental design, comparative analysis of mechanistic hypotheses, evaluation of the quality of toxicological studies, and risk assessment.

Concentration levels of phthalate metabolites in wild boar hair samples

Phthalates used in the industry penetrate the environment and negatively affect humans and animals. Hair samples seem to be the best matrix for studies on long-term exposure to phthalates, but till now they were used only in investigations on humans. Moreover, the knowledge of the wild terrestrial animal exposure to phthalates is extremely limited. This study aimed to establish of concentration levels of selected phthalate metabolites (i.e. monomethyl phthalate-MMP, monoethyl phthalate-MEP, mono-isobutyl phthalate-MiBP, monobutyl phthalate-MBP, monobenzyl phthalate-MBzP, mono-cyclohexyl phthalate-MCHP, mono(2-ethylhexyl) phthalate-MEHP and mono-n-octyl phthalate-MOP) in wild boar hair samples using liquid chromatography with mass spectrometry (LC-MS) analysis. MEHP was noted in 90.7% of samples with mean 66.17 ± 58.69 pg/mg (median 49.35 pg/mg), MMP in 59.3% with mean 145.1 ± 310.6 pg/mg (median 64.45 pg/mg), MiBP in 37.0% with mean 56.96 ± 119.4 pg/mg (median < limit of detection-LOD), MBP in 35.2% with mean 19.97 ± 34.38 pg/mg (median < LOD) and MBzP in 1.9% with concentration below limit of quantification. MEP, MCHP, and MOP have not been found in wild boar hair samples during this study. The results have shown that wild boars are exposed to phthalates and hair samples may be used as a matrix during studies on levels of phthalate metabolites in wild animals.

The evaluation of skin sensitization potential of the UVCB substance diisopentyl phthalate by in silico and in vitro methods

Diisopentyl phthalate (DiPeP) is primarily used as a plasticizer or additive within the production of polyvinyl chloride (PVC), and has many additional industrial applications. Its metabolites were recently found in urinary samples of pregnant women; thus, this substance is of concern as relates to human exposure. Depending upon the nature of the alcohol used in its synthesis, DiPeP may exist either as a mixture consisting of several branched positional isomers, or as a single defined structure. This article investigates the skin sensitization potential and immunomodulatory effects of DiPeP CAS No. 84777-06-0, which is currently marketed and classified as a UVCB substance, by in silico and in vitro methods. Our findings showed an immunomodulatory effect for DiPeP in LPS-induced THP-1 activation assay (increased CD54 expression). In silico predictions using QSAR TOOLBOX 4.5, ToxTree, and VEGA did not identify DiPeP, in the form of a discrete compound, as a skin sensitizer. The keratinocyte activation (Key Event 2 (KE2) of the adverse outcome pathway (AOP) for skin sensitization) was evaluated by two different test methods (HaCaT assay and RHE assay), and results were discordant. While the HaCaT assay showed that DiPeP can activate keratinocytes (increased levels of IL-6, IL-8, IL-1α, and ILA gene expression), in the RHE assay, DiPeP slightly increased IL-6 release. Although inconclusive for KE2, the role of DiPeP in KE3 (dendritic cell activation) was demonstrated by the increased levels of CD54 and IL-8 and TNF-α in THP-1 cells (THP-1 activation assay). Altogether, findings were inconclusive regarding the skin sensitization potential of the UVCB DiPeP-disagreeing with the results of DiPeP in the form of discrete compound (skin sensitizer by the LLNA assay). Additional studies are needed to elucidate the differences between DiPeP isomer forms, and to better understand the applicability domains of non-animal methods in identifying skin sensitization hazards of UVCB substances.

DEHP (di(2-ethylhexyl)phthalate) stimulates skin pigmentation by perturbing cytoskeletal homeostasis

Phthalates are extensively employed plasticizers crucial for conferring flexibility and plasticity to polyvinyl chloride. Phthalates, including DEHP (di(2-ethylhexyl)phthalate), present in diverse products, have been identified in fine dust and are capable of infiltrating the body, potentially posing health hazards. Importantly, melanocytes, existing at the basal layer of the epidermis, are susceptible to toxic substances. In our study, we employed the 3D human pigmented epidermis model, MelanoDerm™, along with the B16F10 murine melanoma cell line, to examine the influence of DEHP exposure on melanocytes. The exposure to low concentrations of DEHP (~ 5 μM), resulted in the extension of melanocyte dendrites, indicating the stimulation of melanocytes. Analysis of gene expression and protein profiles unveiled the up-regulation of MITF, Arpc2, and TRP1 genes subsequent to DEHP exposure, indicating alterations in cytoskeletal and melanosome-related genetic and protein components in melanocytes. Notably, increased pigmentation was observed in MelanoDerm™ following DEHP exposure. DEHP-stimulated reactive oxygen species generation appeared to be involved in these events since the antioxidant, ascorbic acid attenuated ROS generation and MITF upregulation. Collectively, our study demonstrated that DEHP exposure can induce cytoskeletal disturbance and skin pigmentation through oxidative stress.

Human skin absorption of three phthalates

Population studies reveal widespread exposure to phthalates. Understanding their absorption, distribution, metabolism, and excretion is vital to reduce exposure. However, data on skin absorption remain limited. We thus aim to characterize the skin permeation of three phthalates in a mixture, neat or in emulsion; di(2-ethylhexyl) phthalate (d4-DEHP), dibutyl phthalate (d4-DBP), and diethyl phthalate (d4-DEP), by comparing in vitro human skin (800 µm) permeation (24 hours) results using flow-through diffusion cells with urine results obtained from volunteers exposed to the same mixture applied to a forearm (40 cm2). Metabolites were analyzed in receptor fluids and urine. Phthalates crossed the skin barrier and metabolized into monoesters before elimination. Increased permeation was observed for phthalates in emulsion compared to neat substances, with polyethylene glycol (PEG) in the receptor fluid enhancing emulsion permeation, but not affecting neat substances. In vitro results mirrored in vivo findings: DEP showed rapid permeation (J: ∼2 ug/cm2/h) and urinary excretion peaking at six hours post-application, whereas DBP exhibited slower kinetics (J: ∼0.1 ug/cm2/h), with a urinary peak at 15-17 hours post-application. DEHP had minimal permeation (J: ∼0.0002 ug/cm2/h) with no observable urinary peak. These findings underscore the importance of comprehending phthalate skin absorption for effective exposure mitigation strategies.

Urinary phthalate/DINCH metabolites associations with kisspeptin and reproductive hormones in teenagers: A cross-sectional study from the HBM4EU aligned studies

BACKGROUND

Exposure to phthalate/DINCH metabolites can induce human reproductive toxicity, however, their endocrine-disrupting mechanisms are not fully elucidated.

OBJECTIVE

To investigate the association between concentrations of phthalate/DINCH metabolites, serum kisspeptin, and reproductive hormones among European teenagers from three of the HBM4EU Aligned Studies.

METHODS

In 733 Belgian (FLEHS IV study), Slovak (PCB cohort follow-up), and Spanish (BEA study) teenagers, ten phthalate and two DINCH metabolites were measured in urine by high-performance liquid chromatography-tandem mass spectrometry. Serum kisspeptin (kiss54) protein, follicle-stimulating hormone (FSH), total testosterone (TT), estradiol (E2), and sex hormone-binding globulin (SHBG) levels were measured by immunosorbent assays. Free Androgen Index (FAI) was calculated as a proxy of free testosterone. Adjusted sex-stratified linear regression models for individual studies, mixed effect models (LME) accounting for random effects for pooled studies, and g-computation and Bayesian kernel machine regression (BKMR) models for the phthalate/DINCH mixture were performed.

RESULTS

The LME suggested that each IQR increase in ln-transformed levels of several phthalates was associated with lower kisspeptin [MnBP: %change (95%CI): -2.8 (-4.2;-0.4); MEHP: -1.4 (-3.4,0.2)] and higher FSH [∑DINP: 11.8 (-0.6;25.1)] levels in females from pooled studies. G-computation showed that the phthalates/DINCH mixture was associated with lower kisspeptin [-4.28 (-8.07;-0.34)] and higher FSH [22.13 (0.5;48.4)] also in females; BKMR showed similar although non-significant pattern. In males, higher phthalates metabolites [MEHP: -12.22 (-21.09;-1.18); oxo-MEHP: -12.73 (-22.34;-1.93)] were associated with lower TT and FAI, although higher DINCH [OH-MINCH: 16.31 (6.23;27.35), cx-MINCH: 16.80 (7.03;27.46), ∑DINCH: 17.37 (7.26;29.74)] were associated with higher TT levels. No mixture associations were found in males.

CONCLUSION

We observed sex-specific associations between urinary concentrations of phthalate/DINCH metabolites and the panel of selected effect biomarkers (kisspeptin and reproductive hormones). This suggests that exposure to phthalates would be associated with changes in kisspeptin levels, which would affect the HPG axis and thus influence reproductive health. However, further research is needed, particularly for phthalate replacements such as DINCH.

In silico investigation of the role of miRNAs in a possible developmental origin of prostate cancer in F1 and F2 offspring of mothers exposed to a phthalate mixture

A previous study using miRNA sequencing revealed that exposure to a mixture of phthalates during pregnancy and lactation dysregulated rno-miR-184 and rno-miR-141-3p in the ventral prostate (VP) of offspring. Here, rno-miR-184 and rno-miR-141-3 expressions were obtained by RT-qPCR in the VP of F1 males as well as in F2 offspring, aiming to establish a relationship with possible oncogenic targets through in silico analyses with multigenerational approach. Additionally, some targets were measured by western blots to highlight a possible relationship between the deregulated miRNAs and some of their targets. VP samples from rats exposed to a mixture of phthalates maternally during pregnancy and lactation (GD10 to PND21-F1) and VP from offspring (F2) were examined. The phthalate mixture at both concentrations (20 μg and 200 mg/kg/day) increased the expression of both miRNAs in the F1 (PND22 and 120) and F2 (descendants of F1-treated males) prostate. Target prediction analysis revealed that both microRNAs are responsible for modulating the expression and synthesis of 40 common targets. A phthalate target association analysis and the HPA database showed an interesting relationship among these possible miRNAs modulated targets with prostate adenocarcinoma and other oncogenic processes. Western blots showed alteration in P63, P53, WNT5, and STAT3 expression, which are targeted by the miRNAs, in the VP of F1/F2 males. The data draw attention to the epigenetic modulation in the prostate of descendants exposed to phthalates and adds to one of the few currently found in the literature to point to microRNAs signature as biomarkers of exposure to plasticizers.

Occurrence and abundance of microplastics and plasticizers in landfill leachate from open dumpsites in Sri Lanka

This is the first attempt that investigate the abundance of plasticizers in leachate sediment in the scientific literature, alongside the debut effort to explore the abundance of microplastics and plasticizers in landfill leachate and sediment in Sri Lanka. Microplastics in sizes ranging from ≥2.0-5.0, ≥1.0-2.0, and ≥ 0.5-1.0 mm were extracted from the leachate draining from ten municipal solid waste open dump sites and sediment samples covering seven districts. Microplastics were extracted by density separation (Saturated ZnCl2) followed by wet peroxide digestion and the chemical identification was conducted by Fourier Transform Infrared spectroscopy. Plasticizers were extracted to hexane and analyzed by high-performance liquid chromatography. The total mean microplastic abundance in leachate was 2.06 ± 0.62 mg/L whereas it was 363 ± 111 mg/kg for leachate sediments. The most frequently found polymer type was polyethylene (>50%), and white color was dominant. The average concentration of bisphenol A (BPA), benzophenone (BP) and diethyl-hydrogen phthalate (DHEP) in leachate was 158 ± 84.4, 0.75 ± 0.16 and 170 ± 85.8 μg/L respectively. Furthermore, BP and DHEP in leachate sediment was 100 ± 68.3 and 1034 ± 455 μg/kg respectively. As landfill leachate is directly discharged into nearby surface and groundwater bodies that serve as sources of drinking water, the study highlights the potential concerns of microplastic and plasticizer exposure to the surrounding Sri Lankan community through consumption of contaminated drinking water. Therefore, there is a timely need of develop the effective waste management and pollution control measures to minimize the possible threats to both the environment and human health.

Endocrine effect of phthalate metabolites and a butterfly effect of prenatal exposure to androgens on qualitative aspects of female sexual response- an initial survey

There is growing evidence that endocrine disruptive chemicals have deleterious effects on sexual and reproductive function. To examine subjective sexual functions in human females and their relationship to postnatal phthalate exposure and perinatal androgenization, a Sexuality Score (SS) was established from a first-stage survey questionnaire of subjective sexual function filled out by female university students (n = 68; average age 25.23 ± 5.17 years; rural 25.51 ± 6.74 vs. urban 25.85 ± 1.43 years). Seventeen phthalate metabolites in urine samples were analyzed by high-performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS). Females were also assessed for the 2D:4D digit ratio as an index of perinatal androgenization. The mean age of menarche was 12.82 ± 1.35 years (rural 12.59 ± 1.39 vs. urban 13.18 ± 1.27; p = 0.01). The mean age at first sexual intercourse was 14.88 ± 6.89 years (rural 14.62 ± 7.20 vs. urban 15.24 ± 6.55), and as the age of first sexual intercourse increases, the SS score tends to increase as well, albeit moderately (r = 0.25, p = 0.037). Mono-iso-butyl phthalate, mono(2-ethyl-5-carboxypentyl) phthalate, mono(hydroxy-n-butyl) phthalate, mono(2-ethyl-5-oxohexyl) phthalate (p ≤ 0.05) and mono(2-carboxymethylhexyl) phthalate (p ≤ 0.01) were negatively associated with SS. A compounding butterfly effect of prenatal exposure to androgens was observed with disruptive effects of mono(2-ethyl-5-oxohexyl) phthalate and mono(2-ethyl-5-carboxypentyl) phthalate on sexual function. Exposure to phthalates in adult females may lead to disruption of subjective sexual function, especially concerning sexual desire and sexual satisfaction, and perinatal androgenization could augment these effects.

Subacute exposure to DEHP leads to impaired decidual reaction and exacerbates the risk of early miscarriage in mice

OBJECTIVES

To investigate the effect of subacute exposure of Di (2-ethylhexyl) phthalate (DEHP) on endometrial decidualization and early pregnancy miscarriage in mice.

METHODS

CD1 mice were orally administrated with 300 (low-dose group), 1000 (medium-dose group), or 3000 mg·kg－1·d－1 DEHP (1/10 LD50, high-dose group) for 28 days, respectively. An early natural pregnancy model and an artificially induced decidualization model were established. The uterine tissues were collected on D7 of natural pregnancy and D8 of artificially induced decidualization, respectively. The effects of a subacute exposure to DEHP on the decidualization of mice were detected by HE staining, Masson staining, TUNEL assay, and Western blotting. A model of spontaneous abortion was constructed in mice after subacute exposure to 300 mg·kg－1·d－1 DEHP, and the effect of impaired decidualization on pregnancy was investigated by observing the pregnancy outcome on the 10th day of gestation.

RESULTS

Compared with the control group, the conception rate was significantly decreased in the high-dose DEHP subacute exposure group (P<0.05). HE staining showed that, compared with the control group, the decidual stromal cells in the low- and medium-dose exposure groups were disorganized, the nuclei of the cells were irregular, the cytoplasmic staining was uneven, and the number of polymorphonuclear cells was significantly reduced. Masson staining showed that compared with the control group, the collagen fibers in the decidua region of the DEHP low-dose group and the medium-dose group were more distributed, more abundant and more disorderly. TUNEL assay showed increased apoptosis in the decidua area compared to the control group. Western blotting showed that the expression of BMP2, a marker molecule for endometrial decidualization, was significantly reduced (P<0.05 or P<0.01). The abortion rate and embryo resorption rate were increased, and the number of embryos, uterine wet weight, uterine area and placenta wet weight were decreased in DEHP low-dose group compared to the control group stimulated by mifepristone, an abortifacient drug (P<0.05 or P<0.01).

CONCLUSIONS

Subacute exposure to DEHP leads to impaired endometrial decidualization during early pregnancy and exacerbates the risk of adverse pregnancy outcomes in mice.

Mixtures of phthalates disrupt expression of genes related to lipid metabolism and peroxisome proliferator-activated receptor signaling in mouse granulosa cells

Phthalates are a class of known endocrine disrupting chemicals that are found in common everyday products. Several studies associate phthalate exposure with detrimental effects on ovarian functions, including growth and development of the follicle and production of steroid hormones. We hypothesized that dysregulation of the ovary by phthalates may be mediated by phthalate toxicity towards granulosa cells, a major cell type in ovarian follicles responsible for key steps of hormone production and nourishing the developing oocyte. To test the hypothesis that phthalates target granulosa cells, we harvested granulosa cells from adult CD-1 mouse ovaries and cultured them for 96 hours in vehicle control, a phthalate mixture, or a phthalate metabolite mixture (0.1-100 μg/mL). After culture, we measured metabolism of the phthalate mixture into monoester metabolites by the granulosa cells, finding that granulosa cells do not significantly contribute to ovarian metabolism of phthalates. Immunohistochemistry of phthalate metabolizing enzymes in whole ovaries confirmed that these enzymes are not strongly expressed in granulosa cells of antral follicles and that ovarian metabolism of phthalates likely occurs primarily in the stroma. RNA sequencing of treated granulosa cells identified 407 differentially expressed genes, with overrepresentation of genes from lipid metabolic processes, cholesterol metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. Expression of significantly differentially expressed genes related to these pathways were confirmed using qPCR. Our results agree with previous findings that phthalates and phthalate metabolites have different effects on the ovary and interfere with PPAR signaling in granulosa cells.

Prenatal phthalate exposure and fetal penile length and width

BACKGROUND

Phthalates are endocrine-disrupting chemicals with anti-androgenic qualities and studies reported associations between prenatal phthalate exposure and infant genitalia. This study investigated whether increased prenatal phthalate exposure is associated with decreased fetal penile measures.

METHODS

Data was from the New York University Children's Health and Environment Study (2016-2019). Maternal urinary concentrations of 16 phthalate metabolites were quantified at <18 weeks gestation as a proxy for fetal exposure (n = 334 male pregnancies). We retrospectively measured penile length and width using ultrasounds conducted 18-24 weeks gestation (n = 173 fetuses). Associations of maternal urinary levels of phthalates with fetal penile length and width were determined using linear regression models.

RESULTS

57.2% of women were Hispanic, 31.8% Non-Hispanic White, 6.4% Asian, 2.3% Non-Hispanic Black, and 2.3% multiple races. Mean maternal age was 32 years (standard deviation [SD] = 5.7). Mean penile length was 7.13 mm (SD = 1.47) and width was 6.16 mm (SD = 0.87). An inverse relationship was observed between maternal levels of mono-ethyl phthalate and fetal penile length, and mono-(7-carboxy-n-heptyl) phthalate and penile width, though estimates were small and not significant when considering correction for multiple comparisons.

CONCLUSIONS

In our cohort we found no clinically meaningful associations between early pregnancy phthalate exposure and fetal penile length or width.

IMPACT

First-trimester phthalate metabolites were assessed in pregnant women in New York City. Penile length and width were retrospectively measured on clinically assessed ultrasounds conducted ≥18 weeks and <24 weeks of gestation. In this cohort, no clinically meaningful associations were observed between first-trimester prenatal phthalate exposure and fetal penile length. This study contributes to the limited but growing research on the impact of prenatal phthalate exposure on male fetal genital development. The results emphasize that there may not be a clear association between prenatal phthalate exposure and fetal penile length and width, and further research on this topic may be required.

Extracellular Vesicles in Environmental Toxicological Studies: Association between Urinary Concentrations of Phthalate Metabolites and Exosomal miRNA Expression Profiles

Phthalates are chemical compounds, mainly used as additives in plastics, which are known to induce harmful impacts to the environment and human health due to their ability to act as hormone-mimics. Few studies have been reported on the relationship between human exposure to phthalates and the level of circulating microRNAs (miRs), especially those miRs encapsulated in extracellular vesicles/exosomes or exosome-like vesicles (ELVs). We examined the relationship of ELV-miR expression patterns and urine of adult men with five phthalate metabolites (i.e., mono isobutyl phthalate, mono-n-butyl phthalate, mono benzyl phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethylhexyl) phthalate) to identify potential biomarkers and relevant pathways. We found significant positive associations which were further confirmed by multivariable analysis. Overall, our analyses showed that the Σ phthalate metabolite concentration was associated with a significant increase in the expression level of two miRs found in ELV: miR-202 and miR-543. Different pathways including cancer and immune-related responses were predicted to be involved in this relationship. Analyzing the specific downstream target genes of miR-202 and miR-543, we identified the phosphatase and tensin homolog (PTEN) as the key gene in several converging pathways. In summary, the obtained results demonstrate that exposure to environmental phthalates could be related to altered expression profiles of specific ELV-miRs in adult men, thereby demonstrating the potential of miRs carried by exosomes to act as early effect biomarkers.

What is driving the global decline of human fertility? Need for a multidisciplinary approach to the underlying mechanisms

An intense period of human population expansion over the past 250 years is about to cease. Total fertility rates are falling dramatically all over the world such that highly industrialized nations, including China and the tiger economies of SE Asia, will see their populations decline significantly in the coming decades. The socioeconomic, geopolitical and environmental ramifications of this change are considerable and invite a multidisciplinary consideration of the underlying mechanisms. In the short-term, socioeconomic factors, particularly urbanization and delayed childbearing are powerful drivers of reduced fertility. In parallel, lifestyle factors such as obesity and the presence of numerous reproductive toxicants in the environment, including air-borne pollutants, nanoplastics and electromagnetic radiation, are seriously compromising reproductive health. In the longer term, it is hypothesized that the reduction in family size that accompanies the demographic transition will decrease selection pressure on high fertility genes leading to a progressive loss of human fecundity. Paradoxically, the uptake of assisted reproductive technologies at scale, may also contribute to such fecundity loss by encouraging the retention of poor fertility genotypes within the population. Since the decline in fertility rate that accompanies the demographic transition appears to be ubiquitous, the public health implications for our species are potentially devastating.

Phthalates are detected in the follicular fluid of adolescents and oocyte donors with associated changes in the cumulus cell transcriptome

Purpose

To investigate follicular fluid (FF) phthalate levels in adolescents undergoing fertility preservation compared to oocyte donors and explore its association with ovarian reserve and cumulus cell gene expression.

Methods

20 Adolescents (16.7 ± 0.6 years old) and 24 oocyte donors (26.2 ± 0.4 years old) undergoing fertility preservation were included in the study. Patient demographics, ovarian stimulation and oocyte retrieval outcomes were analyzed for each group. FF levels of 9 phthalate metabolites were assessed individually and as molar sums representative of common compounds (all phthalates: ΣPhthalates; DEHP: ΣDEHP), exposure sources (plastics: ΣPlastic; personal care products: ΣPCP), and modes of action (anti-androgenic: ΣAA) and compared between the two groups.

Results

Follicular fluid ΣPlastic and ΣPCP levels were significantly higher in adolescents compared to oocyte donors (p<0.05). Follicular fluid ΣDEHP, ΣPlastic, ΣPCP, ΣAA, and ΣPhthalates levels were positively associated with antral follicle count (AFC) (p<0.05) in oocyte donors when adjusted for age, BMI, and race/ethnicity. RNA-seq analysis revealed 248 differentially expressed genes (DEGs) in cumulus cells of adolescents within the top quartile (n=4) of FF ΣPhthalates levels compared to the adolescents within the bottom half (n=9). Genes enriched in pathways involved in cell motility and development were significantly downregulated.

Conclusion

Adolescents undergoing fertility preservation cycles demonstrate higher levels of phthalate metabolites in their follicular fluid compared to oocyte donors. Phthalate metabolite levels in FF are associated with higher AFC levels in oocyte donors. Higher phthalate levels in FF are associated with alterations in the cumulus cells transcriptome in adolescents.

Impact of DEHP exposure on female reproductive health: Insights into uterine effects

Several endocrine disrupting compounds released from plastics, including polyfluoroalkyl substances, bisphenols, flame retardants, phthalates and others, are of great concern to human health due to their high toxicity. This review discusses the effects of di-(2-ethylhexyl) phthalate (DEHP), the most common member of the phthalate family, on female reproduction. In vitro and in vivo studies link DEHP exposure to impaired hypothalamic-pituitary-ovarian s (HPO) axis function, alteration of steroid-hormone levels and dysregulation of their receptors, and changes in uterine morphophysiology. In addition, high urinary DEPH levels have been associated with several reproductive disorders in women, including endometriosis, fibromyoma, fetal growth restriction and pregnancy loss. These data suggest that DEHP may be involved in the pathophysiology of various female reproductive diseases. Therefore, exposure to these compounds should be considered a concern in clinician surveillance practices for women at reproductive age and should be regulated to protect their health and that of their progeny.

Association between phthalates and sleep problems in the U.S. adult females from NHANES 2011-2014

There is little research on the relationship between phthalates exposure and sleep problems in adult females, with existing studies only assessing the association between exposure to individual phthalates with sleep problems.     We aimed to analyse the relationship between phthalates and sleep problems in 1366 US females aged 20 years and older from the 2011-2014 National Health and Nutrition Examination Survey (NHANES) by age stratification. Multivariate logistic regression showed that the fourth quartile of MECPP increased the risk of sleep problems in females aged 20-39 compared with the reference quartile (OR: 1.87, 95% CI: 1.14, 3.08). The WQS index was significantly associated with the sleep problems in females aged 20-39. In the BKMR, a positive overall trend between the mixture and sleep problems in females aged 20-39. In this study, we concluded that phthalates might increase the risk of sleep problems in females aged 20-39.

Endocrine Disruptors and Metabolic Changes: Impact on Puberty Control

OBJECTIVE

This study aims to explore the significant impact of environmental chemicals on disease development, focusing on their role in developing metabolic and endocrine diseases. The objective is to understand how these chemicals contribute to the increasing prevalence of precocious puberty, considering various factors, including epigenetic changes, lifestyle, and emotional disturbances.

METHODS

The study employs a comprehensive review of descriptive observational studies in both human and animal models to identify a degree of causality between exposure to environmental chemicals and disease development, specifically focusing on endocrine disruption. Due to ethical constraints, direct causation studies in human subjects are not feasible; therefore, the research relies on accumulated observational data.

RESULTS

Puberty is a crucial life period with marked physiological and psychological changes. The age at which sexual characteristics develop is changing in many regions. The findings indicate a correlation between exposure to endocrine-disrupting chemicals and the early onset of puberty. These chemicals have been shown to interfere with normal hormonal processes, particularly during critical developmental stages such as adolescence. The research also highlights the interaction of these chemical exposures with other factors, including nutritional history, social and lifestyle changes, and emotional stress, which together contribute to the prevalence of precocious puberty.

CONCLUSION

Environmental chemicals significantly contribute to the development of certain metabolic and endocrine diseases, particularly in the rising incidence of precocious puberty. Although the evidence is mainly observational, it adequately justifies regulatory actions to reduce exposure risks. Furthermore, these findings highlight the urgent need for more research on the epigenetic effects of these chemicals and their wider impact on human health, especially during vital developmental periods.

Environmental Factors as the Main Hormonal Disruptors of Male Fertility

INTRODUCTION AND OBJECTIVE

Many scientific reports confirm a systematic decline in male semen parameters over the last decades. This phenomenon has been observed in all parts of the world, and its occurrence is associated, among others, with the hazardous effects of some environmental factors. The environmental factors for which the adverse effect on male fertility has been proven include water, air, and soil pollution, as well as electromagnetic fields and ionizing radiation. The aim of this article was the evaluation of the effect of selected environmental factors on male reproductive capacity based on an analysis of the current scientific reports.

REVIEW METHODS

A systematic literature review was carried out using three databases: PubMed, EMBASE, and Scopus. The search was limited to the period from 2015 until the end of December 2023. Brief description of the state of knowledge: Environmental factors, such as heavy metals, tobacco smoke, pesticides, dioxins, furans, phthalates, and bisphenols, are well-tested substances that exert an adverse effect on male fertility. A harmful effect of electromagnetic fields and water and air pollution on reproductive functions may be expected; however, this has not been fully proven.

SUMMARY

Results obtained by many researchers published to date should evoke great concern regarding the quality of the environment in which we live, as well as fears about the effect of environmental factors not only on male fertility, but also on all aspects of human health. The majority of environmental pollutants affect the male body by causing oxidative stress and through their effect on the endocrine system.

Phthalate metabolites and sex steroid hormones in relation to obesity in US adults: NHANES 2013-2016

Background

Obesity and metabolic syndrome pose significant health challenges in the United States (US), with connections to disruptions in sex hormone regulation. The increasing prevalence of obesity and metabolic syndrome might be associated with exposure to phthalates (PAEs). Further exploration of the impact of PAEs on obesity is crucial, particularly from a sex hormone perspective.

Methods

A total of 7780 adult participants in the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2016 were included in the study. Principal component analysis (PCA) coupled with multinomial logistic regression was employed to elucidate the association between urinary PAEs metabolite concentrations and the likelihood of obesity. Weighted quartiles sum (WQS) regression was utilized to consolidate the impact of mixed PAEs exposure on sex hormone levels (total testosterone (TT), estradiol and sex hormone-binding globulin (SHBG)). We also delved into machine learning models to accurately discern obesity status and identify the key variables contributing most to these models.

Results

Principal Component 1 (PC1), characterized by mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) as major contributors, exhibited a negative association with obesity. Conversely, PC2, with monocarboxyononyl phthalate (MCNP), monocarboxyoctyl phthalate (MCOP), and mono(3-carboxypropyl) phthalate (MCPP) as major contributors, showed a positive association with obesity. Mixed exposure to PAEs was associated with decreased TT levels and increased estradiol and SHBG. During the exploration of the interrelations among obesity, sex hormones, and PAEs, models based on Random Forest (RF) and eXtreme Gradient Boosting (XGBoost) algorithms demonstrated the best classification efficacy. In both models, sex hormones exhibited the highest variable importance, and certain phthalate metabolites made significant contributions to the model's performance.

Conclusions

Individuals with obesity exhibit lower levels of TT and SHBG, accompanied by elevated estradiol levels. Exposure to PAEs disrupts sex hormone levels, contributing to an increased risk of obesity in US adults. In the exploration of the interrelationships among these three factors, the RF and XGBoost algorithm models demonstrated superior performance, with sex hormones displaying higher variable importance.

Assessment of baby disposable diapers application for urine collection and determination of phthalate metabolites

The baby disposable diapers were investigated as a sampling material for urine collection and validated for the evaluation of the exposure of children to xenobiotics. Phthalate metabolites detected in urine samples were chosen as proof-of-concept analytes. For the determination of phthalate metabolites in children's urine samples, high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was used. Two sampling approaches were compared, namely sterile containers and baby disposable diapers. Thirty urine samples from infants and toddlers were analyzed by both methods in parallel and the results were compared. It was found that for diaper sampling, lower concentrations of the metabolites were observed, however, the general distribution for particular metabolites remains the same for both methods. For most of the metabolites high determination coefficients were obtained, namely 0.9929 for MEHHP, 0.9836 for MMP, 0.9796 for MECPP, and 0.9784 for 2-cx-MMHP. For MEOHP the determination correlation coefficient was 0.9154, while for MBP was - 0.7771 and MEHP was - 0.5228. In general, for diaper sampling an underestimation for 2-cx-MMHP and MEOHP was observed, while for MMP diaper-based approach provides overestimation. However, the proposed procedure confirms the possibility of using baby disposable diapers as a material for the collection of urine samples for biomonitoring purposes and fast screening of phthalates exposure.

Association of co-exposure to polycyclic aromatic hydrocarbons and phthalates with oxidative stress and inflammation

Exposure to multiple environmental pollutants is ubiquitous and inevitable, but studies investigating their exposure effects on oxidative stress or inflammation have mainly been restricted to single-pollutant models. This study investigated the association of co-exposure to polycyclic aromatic hydrocarbons and phthalates with oxidative stress and inflammation. Using a cross-sectional study in adults, we measured urinary concentrations of metabolites of polycyclic aromatic hydrocarbons (OH-PAHs) and phthalates (mPAEs), urinary oxidative stress biomarker 8-hydroxy-2'-deoxyguanosine, and 9 inflammatory biomarkers in paired blood samples. The associations of urinary OH-PAHs and mPAEs with oxidative stress and inflammation biomarkers were evaluated by different statistical models. The Bayesian kernel machine regression and quantile g-computation was used to examine the joint effects, and increased levels of urinary concentrations of OH-PAHs and mPAEs were associated with elevated 8-hydroxy-2'-deoxyguanosine level and white blood cell counts. Exposure to polycyclic aromatic hydrocarbons contributed more significantly to inflammation, while exposure to phthalates contributed more to oxidative stress. Monoisobutyl phthalate was identified as the most significant metabolite contributing to elevated oxidative stress levels. 1-Hydroxypyrene was negatively associated with platelet, and monomethyl phthalate was significantly positively associated with interleukin 6 in multivariate linear regression. The restricted cubic spline analysis revealed non-linear patterns of 3-hydroxyfluorene with white blood cell, lymphocyte, neutrophil, and C-reactive protein. The results indicated significant associations between increased co-exposure to polycyclic aromatic hydrocarbons and phthalates with elevated oxidative stress and inflammation. Further investigation is needed to elucidate the underlying biological mechanisms and to determine the potential public health implications.

Food, nutrition, and fertility: from soil to fork

Food and nutrition-related factors, including foods and nutrients consumed, dietary patterns, use of dietary supplements, adiposity, and exposure to food-related environmental contaminants, have the potential to impact semen quality and male and female fertility; obstetric, fetal, and birth outcomes; and the health of future generations, but gaps in evidence remain. On 9 November 2022, Tufts University's Friedman School of Nutrition Science and Policy and the school's Food and Nutrition Innovation Institute hosted a 1-d meeting to explore the evidence and evidence gaps regarding the relationships between food, nutrition, and fertility. Topics addressed included male fertility, female fertility and gestation, and intergenerational effects. This meeting report summarizes the presentations and deliberations from the meeting. Regarding male fertility, a positive association exists with a healthy dietary pattern, with high-quality evidence for semen quality and lower quality evidence for clinical outcomes. Folic acid and zinc supplementation have been found to not impact male fertility. In females, body weight status and other nutrition-related factors are linked to nearly half of all ovulation disorders, a leading cause of female infertility. Females with obesity have worse fertility treatment, pregnancy-related, and birth outcomes. Environmental contaminants found in food, water, or its packaging, including lead, perfluorinated alkyl substances, phthalates, and phenols, adversely impact female reproductive outcomes. Epigenetic research has found that maternal and paternal dietary-related factors can impact outcomes for future generations. Priority evidence gaps identified by meeting participants relate to the effects of nutrition and dietary patterns on fertility, gaps in communication regarding fertility optimization through changes in nutritional and environmental exposures, and interventions impacting germ cell mechanisms through dietary effects. Participants developed research proposals to address the priority evidence gaps. The workshop findings serve as a foundation for future prioritization of scientific research to address evidence gaps related to food, nutrition, and fertility.

Mono-2-ethylhexylphthalate (MEHP) is a potent agonist of human TRPA1 channel

Phthalates are extensively used as plasticizers in diverse consumer care products but have been reported to cause adverse health effects in humans. A commonly used phthalate, di-2-ethylhexylphthalate (DEHP) causes developmental and reproductive toxicities in humans, but the associated molecular mechanisms are not fully understood. Mono-2-ethylhexylphthalate (MEHP), a hydrolytic product of DEHP generated by cellular esterases, is proposed to be the active toxicant. We conducted a screen for sensory irritants among compounds used in consumer care using an assay for human Transient Receptor Potential A1 (hTRPA1). We have identified MEHP as a potent agonist of hTRPA1. MEHP-induced hTRPA1 activation was blocked by the TRPA1 inhibitor A-967079. Patch clamp assays revealed that MEHP induced inward currents in cells expressing hTRPA1. In addition, the N855S mutation in hTRPA1 associated with familial episodic pain syndrome decreased MEHP-induced hTRPA1 activation. In summary, we report that MEHP is a potent agonist of hTRPA1 which generates new possible mechanisms for toxic effects of phthalates in humans.

Phthalate metabolites in urine and follicular fluid in relation to menstrual cycle characteristics in women seeking fertility assistance

BACKGROUND

Phthalates have been shown to disrupt the estrous cycle in animal studies. However, epidemiological research investigating their associations with menstrual cycle characteristics is limited.

OBJECTIVE

To explore the relationships between phthalate exposure and menstrual cycle characteristics among women seeking fertility assistance.

METHODS

We determined the levels of eight phthalate metabolites in both follicular fluid (FF) and urine specimens collected from 441 women in the Tongji Reproductive and Environmental (TREE) cohort, using high-performance liquid chromatography and tandem mass spectrometry. Information about menstrual cycle parameters was obtained through a questionnaire. The impacts of individual and joint exposure to phthalates on menstrual cycle characteristics were assessed using multivariable linear regression, Poisson regression, and quantile g-computation approaches.

RESULTS

After adjusting for relevant covariates, we found that per log10-unit increase in mono(2-ethylhexyl) phthalate (MEHP) level in urine specimens was associated with a decrease of 0.20 days (95 % CI: -0.37, -0.03) in bleeding duration. We also observed that mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) and the sum of di(2-ethylhexyl) phthalate (DEHP) metabolites (∑DEHP) concentrations in FF samples were inversely related to cycle length [β = -1.92 (95 % CI: -3.10, -0.75) and -1.87 (95 % CI: -3.56, -0.19), respectively]. However, we generally observed null associations between phthalate metabolites and irregular cycle, dysmenorrhea, hypomenorrhea, or cycle length variation. Furthermore, we also found that phthalate metabolite mixtures in FF and urine were generally unrelated to menstrual cycle characteristics.

CONCLUSION

Our findings suggest that some DEHP metabolites in FF and urine are inversely associated with menstrual cycle length and menstrual bleeding duration in women attending a fertility center.

HBM4EU e-waste study: Occupational exposure of electronic waste workers to phthalates and DINCH in Europe

Workers involved in the processing of electronic waste (e-waste) are potentially exposed to toxic chemicals, including phthalates and alternative plasticizers (APs). Dismantling and shredding of e-waste may lead to the production of dust that contains these plasticizers. The aim of this study, which was part of the European Human Biomonitoring Initiative (HBM4EU), was to assess the exposure to phthalates (e.g. di-(2-ethylhexyl) phthalate (DEHP), diethyl phthalate (DEP), di-butyl phthalate (DBP), butyl-benzyl phthalate (BBzP), di-isononyl phthalate (DiNP), di-isodecyl phthalate (DiDP) and cyclohexane-1,2-dicarboxylic di-isononyl ester (DINCH) in e-waste workers from ten European companies. This was achieved by (i) analysing urine samples from 106 e-waste workers collected at the beginning and at the end of the work week, (ii) comparing these with urine samples from 63 non-occupationally exposed controls, and (iii) analysing settled floor dust collected in e-waste premises. Significantly higher urinary concentrations of seven out of thirteen phthalates and DINCH metabolites were found in the e-waste workers compared to the control population. However, no significant differences were found between pre- and post-shift concentrations in the e-waste workers. Concentrations of DBP, DEHP and DiDP in dust were weakly to moderately positively correlated with their corresponding urinary metabolite concentrations in the e-waste workers (Spearman's ρ = 0.4, 0.3 and 0.2, respectively). Additionally, significantly lower urinary concentrations of nine phthalates and DINCH metabolites were found in e-waste workers using respiratory protective equipment (RPE) during their work activities, reflecting the potential benefits of RPE to prevent occupational exposure to phthalates and DINCH. The estimated daily intake (EDI) values obtained in this study were lower than the corresponding tolerable daily intake (TDI) adopted by the European Food Safety Authority (EFSA) for the general population, suggesting that the risk for negative health consequences in this population of e-waste workers from exposure to phthalates and DINCH is expected to be low. This was confirmed by the urinary metabolite concentrations of all workers being lower than the HBM4EU guidance values derived for the occupational exposed and general population. This study is one of the first to address the occupational exposure to phthalates and DINCH in Europe in e-waste dismantling workers, combining a human biomonitoring approach with analysis of settled indoor dust.

Prenatal to peripubertal exposure to Di(2-ethylhexyl) phthalate induced endometrial atrophy and fibrosis in female mice

Di(2-ethylhexy) phthalate (DEHP) is a widely used plasticizer that is ubiquitously found in the environment. Using a mouse model, we investigated the impact of early life DEHP exposure ranging from the prenatal to peripubertal developmental period of the female reproductive system. Pregnant female mice were allocated to three groups as follows: control, 100 mg/kg/day, and 500 mg/kg/day DEHP treatment. DEHP exposure was introduced through feeding during pregnancy (3 weeks) and lactation (3 weeks). After weaning, the offspring were also exposed to DEHP through feeding for another 2 weeks. Observations were conducted on female offspring at 10 and 24 weeks. The number of live offspring per dam was significantly lower in the high-DEHP-exposed group (500 mg/kg/day) compared to the control group (7.67 ± 1.24 vs. 14.17 ± 0.31; p < 0.05) despite no difference in pregnancy rates across the groups. Low-DEHP exposure (100 mg/kg/day) resulted to a decreased body weight (36.07 ± 3.78 vs. 50.11 ± 2.11 g; p < 0.05) and decreased left uterine length (10.60 ± 1.34 vs. 14.77 ± 0.82 mm; p < 0.05) in 24-week- old female mice. As early as 10 weeks, endometrial atrophy and fibrosis were observed, and endometrial cystic hyperplasia was noted in female mice at 24 weeks. Our study is the first to demonstrate that female mice exposed to DEHP in the early life developed endometrial fibrosis in the female offspring. Further studies on the consequences of these observations in fecundity and other reproductive functions are warranted.

Oyster Peptide-Zinc Complex Ameliorates Di-(2-ethylhexyl) Phthalate-Induced Testis Injury in Male Mice and Improving Gut Microbiota

Di-(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer, which can cause damage to male reproductive organs, especially the atrophy of the testis. Meanwhile, DEHP can also lead to a decrease in testicular zinc content, but the role of zinc remains unclear. This study aims to prepare oyster peptide-zinc complex (OPZC) to alleviate DEHP-induced reproductive damage in mice. OPZC was successfully obtained through electron microscopy, X-ray diffraction, and thermogravimetric analysis, with stable structure and high water-solubility. Low dose oyster peptide-zinc complex (OPZCL) significantly reduced the reproductive damage caused by DEHP in mice. Further research had shown that OPZCL restored the content of serum hormones and the activity of oxidative stress kinases to normal, while also normalizing testicular zinc and selenium levels. In addition, it also recovered the disorder of gut microbiota, reduced the proportion of Bacteroides, increased the abundance of Ligilactobacillus, and restored the proportion of Acidobacteriota, Chloroflexi, and Proteobacteria. Therefore, OPZCL can relieve the reproductive damage caused by DEHP in mice by restoring testicular zinc homeostasis and the composition of intestinal microbiota, indicating that OPZCL has a potential protective effect on male reproductive health.

Evidence-based identification of breast cancer and associated ovarian and uterus cancer risk components in source waters from high incidence area in the Pearl River Basin, China

Breast cancer, ovarian cancer, and uterus cancer are among the most common female cancers. They are suspected to associate with exposures to specific environmental pollutants, which remain unidentified in source waters. In this work, we focused on the Pearl River Basin region in China, which experienced a high incidence of breast, ovarian, and uterus cancers. Combining cancer patient data, mammalian cell cytotoxicity analyses, and exhaustive historical and current chemical assessments, we for the first time identified source water components that promoted proliferation of mammalian cells, and confirmed their association with these female cancers via the estrogen receptor mediated pathway. Therefore, the components that have previously been found to enhance the proliferation of estrogen receptor-containing cells through endocrine disruption could be the crucial factor. Based on this, components that matched with this toxicological characteristic (i.e., estrogen-like effect) were further identified in source waters, including (1) organic components: phthalates, bisphenol A, nonylphenols, and per-/polyfluoroalkyls; (2) inorganic components: Sb, Co, As, and nitrate. Moreover, these identified water components were present at levels comparable to other regions with high female cancer prevalence, suggesting that the potential risk of these components may not be exclusive to the study region. Together, multiple levels of evidence suggested that long-term co-exposures to source water estrogenic components may be important to the development of breast, ovarian, and uterus cancers.

Scannotation: A Suspect Screening Tool for the Rapid Pre-Annotation of the Human LC-HRMS-Based Chemical Exposome

In an increasingly chemically polluted environment, rapidly characterizing the human chemical exposome (i.e., chemical mixtures accumulating in humans) at the population scale is critical to understand its impact on health. High-resolution mass spectrometry (HRMS) profiling of complex biological matrices can theoretically provide a comprehensive picture of chemical exposures. However, annotating the detected chemical features, particularly low-abundant ones, remains a significant obstacle to implementing such approaches at a large scale. We present Scannotation (https://github.com/scannotation/Scannotation_software), an automated and user-friendly suspect screening tool for the rapid pre-annotation of HRMS preprocessed data sets. This software tool combines several MS1 chemical predictors, i.e., m/z, experimental and predicted retention times, isotopic patterns, and neutral loss patterns, to score the proximity between features and suspects, thus efficiently prioritizing tentative annotations to verify. Scannotation and MS-DIAL4 were used to annotate blood serum samples of 75 Breton adolescents. Scannotation's combination of MS1-based chemical predictors allowed us to annotate 89 chemically diverse environmental compounds with high confidence (confirmed by MS2 when available). These compounds included 62% of emerging molecules, for which no toxicological or human biomonitoring data are reported in the literature. The complementarity observed with MS-DIAL4 results demonstrates the relevance of Scannotation for the efficient pre-annotation of large-scale exposomics data sets.

Endocrine-disrupting chemicals and male reproductive health

Modifiable factors, such as environmental exposures, can impact human fertility. The objective of this review is to summarize the potential effects of exposure to important endocrine-disrupting chemicals on male reproductive health. Most experimental and animal data demonstrate strong evidence for the negative effects of exposure to phenols, phthalates, pesticides, and perfluoroalkyl and polyfluoroalkyl substances on male reproductive health. Although evidence of negative associations in humans was overall strong for phthalates and pesticides, limited and inconclusive relationships were found for the other examined chemical biomarkers. Reasons for the discrepancies in results include but are not limited to, differences in study populations, exposure concentrations, number of samples collected, sample sizes, study design, and residual confounding. Additional studies are needed, particularly for newer phenols and perfluoroalkyl and polyfluoroalkyl substances, given the scarce literature on the topic and increasing exposures over time.

Associations between Phthalate Metabolite Concentrations in Follicular Fluid and Reproductive Outcomes among Women Undergoing in Vitro Fertilization/Intracytoplasmic Sperm Injection Treatment

BACKGROUND

Phthalates have been reported to impair fertility in various studies. However, evidence exploring the associations between phthalate metabolites in follicular fluid (FF) and reproductive outcomes is lacking.

OBJECTIVES

To investigate the associations between phthalate metabolite concentrations in FF and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes among women recruited from a fertility clinic.

METHODS

We included 641 women undergoing IVF/ICSI treatment from December 2018 to January 2020. The levels of eight phthalate metabolites, including monoethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono-n -butyl phthalate (MBP), monobenzyl phthalate (MBzP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), were quantified in FF collected on the oocyte retrieval day. Associations between quartiles of individual phthalate metabolite concentrations and nine IVF/ICSI outcomes, including oocyte yield, mature oocyte number, two distinct pronuclei (2PN) zygote number, fertilization rate, blastocyst formation rate, implantation, clinical pregnancy, miscarriage, and live birth, were estimated with generalized linear models. The effects of phthalate mixtures on IVF/ICSI outcomes were assessed using Bayesian kernel machine regression (BKMR) models.

RESULTS

After adjusting for relevant confounders, elevated quartiles of MBzP, MEHHP, and MEHP in FF were inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes (all p for trends < 0.10 ). In comparison with the lowest quartile, the highest quartile of molar sum of di(2-ethylhexyl) phthalate metabolites (Σ DEHP ) was associated with a reduction of 9.1% [95% confidence interval (CI): - 17.1 % , - 0.37 % ] and 10.3% (95% CI: - 18.8 % , - 0.94 % ) in yielded oocyte and mature oocyte numbers, respectively. Furthermore, the BKMR models revealed inverse associations between phthalate mixtures and the numbers of retrieved oocytes and mature oocytes. We generally found null results for implantation, clinical pregnancy, miscarriage, and live birth.

DISCUSSION

Certain phthalate metabolites in FF are inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes among women undergoing IVF/ICSI treatment. https://doi.org/10.1289/EHP11998.

Impact of endocrine disruptors on peripheral blood mononuclear cells in vitro: role of gender

Humans can be exposed to endocrine disruptors (EDs) in numerous ways. EDs can interfere with endogenous hormones at different levels, resulting in numerous adverse human health outcomes, including immunotoxicity. In this regard, this study aimed to investigate in vitro the possible effects of EDs on immune cells and possible gender differences. Peripheral blood mononuclear cells from healthy humans, both males and females, were exposed to 6 different EDs, namely atrazine (herbicide), cypermethrin (insecticide), diethyl phthalate (plasticizer), 17α-ethynylestradiol (contraceptive drug), perfluorooctanesulfonic acid (persistent organic pollutant), and vinclozolin (fungicide). We evaluated the effect of EDs on RACK1 (receptor for activated C kinase 1) expression, considering it as a bridge between the endocrine and the immune system, and putatively used as screening tool of immunotoxic effects of EDs. The exposure to EDs resulted at different extent in alteration in RACK1 expression, pro-inflammatory activity, natural killer lytic ability, and lymphocyte differentiation, with sex-related differences. In particular, diethyl phthalate and perfluorooctanesulfonic acid resulted the most active EDs tested, with gender differences in terms of effects and magnitude. The results from our study evidenced the ability of EDs to directly affect immune cells.

Preconception Phthalate Exposure and Women's Reproductive Health: Pregnancy, Pregnancy Loss, and Underlying Mechanisms

BACKGROUND

Phthalates are endocrine-disrupting chemicals linked to adverse pregnancy outcomes. Despite the sensitivity of female reproductive processes to oxidation-reduction reaction stress and endocrine disruption, evidence for the impact of women's phthalate exposure on the ability to establish and maintain pregnancy has been inconclusive.

OBJECTIVES

We aimed to determine the relationship of preconception phthalate metabolite exposure with a) fecundability and pregnancy loss and b) markers of potential biological mechanisms, including reproductive hormones, inflammation, and oxidative stress.

METHODS

Data were collected from the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial, a preconception study following 1,228 women who were attempting pregnancy, for up to six menstrual cycles and throughout pregnancy if they became pregnant. Twenty phthalate metabolites were measured in a consecutive 3-d pooled urine sample at enrollment. Pregnancy was determined through urinary human chorionic gonadotropin (hCG) at the expected date of menses during each cycle and pregnancy loss as an observed loss following positive hCG. Highly sensitive C-reactive protein (hsCRP) and isoprostanes were measured at enrollment, and reproductive hormones were measured during the follicular phase, ovulation, and luteal phase. Discrete-time Cox proportional hazards models evaluated the relationship of phthalate metabolites with fecundability and weighted Poisson models with robust variance evaluated the risk of pregnancy loss.

RESULTS

An interquartile range (IQR) higher mono-(2-ethylhexyl) phthalate [fecundability odds ratio  ( FOR ) = 0.88 ; 95% confidence interval (CI): 0.78, 1.00], mono-butyl phthalate (FOR = 0.82 ; 95% CI: 0.70, 0.96), and mono-benzyl phthalate (FOR = 0.85 ; 95% CI: 0.74, 0.98) was associated with lower fecundability. No consistent associations were observed with pregnancy loss. Preconception phthalates were consistently associated with higher hsCRP and isoprostanes, as well as lower estradiol and higher follicle-stimulating hormone across the menstrual cycle.

DISCUSSION

Women's preconception exposure to phthalates was associated with lower fecundability, changes in reproductive hormones, and increased inflammation and oxidative stress. The pre- and periconception periods may represent sensitive windows for intervening to limit the reproductive toxicity of phthalate exposure. https://doi.org/10.1289/EHP12287.

Long-term exposure to exogenous phthalate, masculinity and femininity trait, and gender identity in children: a Chinese 3-year longitudinal cohort study

BACKGROUND

Phthalate esters (PAEs) are known to have hormone-like properties, and there is a growing trend of children expressing a gender identity different from assigned sex. However, there has been limited research in the potential links between PAEs exposure and gender identity.

METHODS

A total of 571 children (278 boys) completed the follow-up from Oct 2017 to Oct 2020 in Childhood Blood Pressure and Environmental Factors (CBPEF) cohort in Xiamen, China. Urinary PAE metabolites were measured at three time of visits using ultraperformance liquid chromatography-tandem mass spectrometry. The Children's Sex Role Inventory scale was used to assess gender identity (masculinity, femininity, androgyny and undifferentiated), and Tanner definition was used to define puberty timing. Generalized linear models and log-binomial regression were used to assess the relationships between PAEs exposure, gender trait scores and gender identity.

RESULTS

Overall, the concentration of most PAEs in more than 90% of participants was above the limit of detection values. In visit 1, there were 10.1% boys with femininity and 11.3% girls with masculinity; while these figures increased to 10.8% and 12.3% during follow-up, respectively. Early puberty onset accounted for 24.8% and 25.6% among boys and girls. Long-term exposure to mono-2-ethylhexyl phthalate (MEHP) (β = 1.20, 95%CI = 0.13, 2.28), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) (β = 1.25, 95%CI = 0.22, 2.28) and mono-2-ethyl-5-oxohexyl phthalate (MEOHP) (β = 1.40, 95%CI = 0.24, 2.56) was associated with the increased differences of femininity trait scores in boys who enter puberty earlier, prolonged exposure to di(2-ethylhexyl) phthalate (DEHP) might also have such a positive impact (β = 1.38, 95%CI = 0.36, 2.41). For gender identity, persistent exposure to low molecular weight phthalates (LMWP) was negatively associated with undifferentiated type among boys entering puberty earlier (RR = 0.18, 95%CI = 0.05, 0.75, P < 0.05), and most of the PAE metabolites exposures showed risk ratios > 1 for their femininity.

CONCLUSION

Long-term exposure to PAEs increase the femininity trait scores in boys with early onset of puberty. Although the mechanisms remain to be determined, environmental pollution might have subtle, yet measurable effects on childhood gender identity. Reducing these chemicals exposure has important public implications on gender development.

A review on solution- and vapor-responsive sensors for the detection of phthalates

Phthalic acid esters, largely referred to as phthalates, are today acknowledged as important pollutants used in the manufacture of polyvinyl chloride (PVC)-based plastics, whose use extends to almost every aspect of modern life. The risk of exposure to phthalates is particularly relevant as high concentrations are regularly found in drinking water, food-contact materials and medical devices, motivating an immense body of research devoted to methods for their detection in liquid samples. Conversely, phthalate vapors have only recently been acknowledged as potentially important atmospheric pollutants and as early fire indicators; additionally, deposition of these vapors can pose significant problems to the proper functioning of spacecraft and diverse on-board devices, leading to major space agencies recognizing the need of developing vapor-responsive phthalate sensors. In this manuscript we present a literature survey on solution- and vapor-responsive sensors and analytical assays for the detection of phthalates, providing a detailed analysis of a vast array of analytical data to offer a clear idea on the analytical performance (limits of detection and quantification, linear range) and advantages provided by each class of sensor covered in this review (electrochemical, optical and vapor-responsive) in the context of their potential real-life applications; the manuscript also gives detailed fundamental information on the various physicochemical responses exploited by these sensors and assays that could potentially be harnessed by new researchers entering the field.

Insights into baby disposable diapers sustainable application

The sustainable use of baby disposable diapers is one of the issues currently being discussed to reduce the undesirable impact on the environment and improve the public's understanding of the proper use of diapers. This issue is a step toward promoting a cleaner, greener, and waste-less environment. In this article, the authors discuss options for a viable future for both people and the planet. We believe that it inspire others in the field of sustainable use of diapers as well as future education in this area. In addition, we believe that it will be a motivation for a researchers working in industry to be focused on the production of new, biodegradable baby diapers as well as on recycling baby diapers waste (for example as composite material for a structural and architectural component of the building).

Endocrine disrupting chemicals and male fertility: from physiological to molecular effects

The deleterious effects of chemical or non-chemical endocrine disruptors (EDs) on male fertility potential is well documented but still not fully elucidated. For example, the detection of industrial chemicals' metabolites in seminal plasma and follicular fluid can affect efficiency of the gametogenesis, the maturation and competency of gametes and has guided scientists to hypothesize that endocrine disrupting chemicals (EDCs) may disrupt hormonal homoeostasis by leading to a wide range of hormonal control impairments. The effects of EDCs exposure on reproductive health are highly dependent on factors including the type of EDCs, the duration of exposure, individual susceptibility, and the presence of other co-factors. Research and scientists continue to study these complex interactions. The aim of this review is to summarize the literature to better understand the potential reproductive health risks of EDCs in France.

Modulation of fetoplacental growth, development and reproductive function by endocrine disrupters

Maternal endocrine homeostasis is vital to a successful pregnancy, regulated by several hormones such as human chorionic gonadotropin, estrogen, leptin, glucocorticoid, insulin, prostaglandin, and others. Endocrine stress during pregnancy can modulate nutrient availability from mother to fetus, alter fetoplacental growth and reproductive functions. Endocrine disrupters such as bisphenols (BPs) and phthalates are exposed in our daily life's highest volume. Therefore, they are extensively scrutinized for their effects on metabolism, steroidogenesis, insulin signaling, and inflammation involving obesity, diabetes, and the reproductive system. BPs have their structural similarity to 17-β estradiol and their ability to bind as an agonist or antagonist to estrogen receptors to elicit an adverse response to the function of the endocrine and reproductive system. While adults can negate the adverse effects of these endocrine-disrupting chemicals (EDCs), fetuses do not equip themselves with enzymatic machinery to catabolize their conjugates. Therefore, EDC exposure makes the fetoplacental developmental window vulnerable to programming in utero. On the one hand prenatal BPs and phthalates exposure can impair the structure and function of the ovary and uterus, resulting in placental vascular defects, inappropriate placental expression of angiogenic growth factors due to altered hypothalamic response, expression of nutrient transporters, and epigenetic changes associated with maternal endocrine stress. On the other, their exposure during pregnancy can affect the offspring's metabolic, endocrine and reproductive functions by altering fetoplacental programming. This review highlights the latest development in maternal metabolic and endocrine modulations from exposure to estrogenic mimic chemicals on subcellular and transgenerational changes in placental development and its effects on fetal growth, size, and metabolic & reproductive functions.