A Review of Biomonitoring of Phthalate Exposures

An automated liquid-liquid extraction platform for high-throughput sample preparation of urinary phthalate metabolites in human biomonitoring

Automated sample preparation reduces variation caused by human factors and improves efficiency, throughput, and reliability, making it especially important in large-scale epidemiological biomonitoring applications. In this study, we demonstrated an automated liquid-liquid extraction platform that streamlines sample preparation for human biomonitoring of urinary phthalate metabolites. This platform integrates temperature-controlled enzymatic hydrolysis, adds extraction solvents, conducts shaking extraction, performs centrifugal separation, and transfers liquids. We optimized extraction solvents for liquid-liquid extraction of urinary phthalate metabolites and compared the extraction efficiency between manual and automated methods. The analytical performance of the platform was validated and compared with those obtained by manual liquid-liquid extraction and solid-phase extraction methods. We applied the automated liquid-liquid platform for determining urinary phthalate metabolites in the human biomonitoring of 232 health participants and evaluated their association with oxidative stress levels. Urinary phthalate metabolite concentrations showed a clear declining trend with increasing age. Males had significantly higher total urinary concentrations of phthalate metabolites than females. Monobutyl phthalate was the dominant metabolite in urine samples, followed by mono-isobutyl phthalate and monoethyl phthalate, with minor gender differences observed among individual metabolites. Trend tests and Bayesian Kernel Machine Regression analysis showed a significant positive association between urinary phthalate metabolites and the oxidative stress markers 8-hydroxyguanosine and 8-hydroxy-2'-deoxyguanosine, and monobutyl phthalate was identified as the most significant metabolite for the elevated 8-hydroxy-2'-deoxyguanosine levels. The automated liquid-liquid extraction platform exhibited high efficiency and reliability in preparing urinary samples for phthalate metabolite analysis, showing great promise in large-scale sample preparation of human biomonitoring applications.

Exploring the link between Di-2-ethylhexyl phthalate (DEHP) exposure and muscle mass: A systematic investigation utilizing NHANES data analysis, network toxicology and molecular docking approaches

Sarcopenia is a syndrome characterized by a progressive, widespread decline in muscle mass and strength. DEHP, a plasticizer involved in daily life and widely used, has been found in various everyday items and causes developmental dysregulation, reproductive impairments, tumorigenesis, and transgenerational disease. However, much remains to be discovered regarding the association between exposure to this environmental toxin and sarcopenia, as well as the toxic targets and molecular mechanisms. This research elucidated the relationship between contact with DEHP and the development of sarcopenia by integrating NHANES data analysis, network toxicology, and molecular docking. 3199 adults were enrolled, and multiple linear regressions were performed to reveal a significant negative correlation between lnDEHP and ALMBMI. Eighty-eight targets associated with DEHP and sarcopenia were identified. Subsequent STRING and Cytoscape screening stressed 20 key targets, including CASP3, BCL2, MMP9, BCL2L1, APP, and CTSS. GO and KEGG enrichment analyses revealed that these targets are involved in ligand-receptor interactions, apoptosis, and calcium signaling pathways. Molecular docking simulations using CB-dock confirmed the high-affinity binding interactions between DEHP and these key targets. This study validated the relationship between DEHP exposure and muscle mass. Further, it provided a theoretical basis for investigating the molecular mechanisms of DEHP exposure-induced skeletal muscle toxicity.

Organophosphate esters and phthalate esters in marine fishes from a coastal area of China: Occurrence, tissue distribution, trophic transfer, and human exposure

Concern over the influences of constant addition of anthropogenic chemicals to the marine environment has attracted public attention. Organophosphate esters (OPEs) and phthalate esters (PAEs) were two emerging chemicals frequently added to a variety of products as flame retardants and plasticizers. However, limited information is available associated with their environmental behaviors in marine environment, and the tissue-specific bioaccumulation and biomagnification of OPEs and PAEs in fish remain subjects of ongoing debate. Hence, 12 OPE and 6 PA E analogues were analyzed in five marine fish species from the coast of Wenchang, Hainan province. The concentrations of Σ12OPEs and Σ6PAEs were in the range of 319-1790 ng/g lw and 400-1370 ng/g lw, respectively. Significantly negative correlations (p value < 0.05) were observed between the concentration of pollutants and their corresponding lipid contents of fish tissues. There were no obvious correlations between the logarithmic transformed concentrations of each OPE and PAE analogue with their corresponding Log KOW value in fish tissues, but OPE and PAE concentrations were likely to reach the highest when Log KOW values were around five. Significantly negative correlations (p value < 0.05) were found between logarithmic transformed concentrations of TCEP, TCP and BBP along with δ15N values in fish species, except for TDCIPP, TEHP and DBP which exhibited an increasing trend with the increasing of δ15N values. Furthermore, human exposure via fish intakes was assessed, and EDI ranged from 73.9 to 1910 ng/kg bw/day for ∑OPEs and 495-4550 ng/kg bw/day for ∑PAEs, respectively, which were both within the safe dose threshold, and the HI values of ΣOPEs and ΣPAEs were much lower than the boundary value of 1.00. This study contributes valuable insights into OPEs and PAEs present in marine organisms as well as robust evidence indicating that most OPE and PAE analogues undergo trophic dilution within marine fish.

Phthalates and uterine disorders

Humans are ubiquitously exposed to environmental endocrine disrupting chemicals such as phthalates. Phthalates can migrate out of products and enter the human body through ingestion, inhalation, or dermal application, can have potential estrogenic/antiestrogenic and/or androgenic/antiandrogenic activity, and are involved in many diseases. As a female reproductive organ that is regulated by hormones such as estrogen, progesterone and androgen, the uterus can develop several disorders such as leiomyoma, endometriosis and abnormal bleeding. In this review, we summarize the hormone-like activities of phthalates, in vitro studies of endometrial cells exposed to phthalates, epigenetic modifications in the uterus induced by phthalate exposure, and associations between phthalate exposure and uterine disorders such as leiomyoma and endometriosis. Moreover, we also discuss the current research gaps in understanding the relationship between phthalate exposure and uterine disorders.

Periods of susceptibility for associations between phthalate exposure and preterm birth: Results from a pooled analysis of 16 US cohorts

BACKGROUND

Phthalate exposure during pregnancy has been associated with preterm birth, but mechanisms of action may depend on the timing of exposure.

OBJECTIVE

Investigate critical periods of susceptibility during pregnancy for associations between urinary phthalate metabolite concentrations and preterm birth.

METHODS

Individual-level data were pooled from 16 US cohorts (N = 6045, n = 539 preterm births). We examined trimester-averaged urinary phthalate metabolite concentrations. Most phthalate metabolites had 2248, 3703, and 3172 observations in the first, second, and third trimesters, respectively. Our primary analysis used logistic regression models with generalized estimating equations (GEE) under a multiple informant approach to estimate trimester-specific odds ratios (ORs) of preterm birth and significant (p < 0.20) heterogeneity in effect estimates by trimester. Adjusted models included interactions between each covariate and trimester.

RESULTS

Differences in trimester-specific associations between phthalate metabolites and preterm birth were most evident for di-2-ethylhexyl phthalate (DEHP) metabolites. For example, an interquartile range increase in mono (2-ethylhexyl) phthalate (MEHP) during the first and second trimesters was associated with ORs of 1.15 (95 % confidence interval [CI]: 0.99, 1.33) and 1.11 (95 % CI: 0.97, 1.28) for preterm birth, respectively, but this association was null in the third trimester (OR = 0.91 [95 % CI: 0.76, 1.09]) (p-heterogeneity = 0.03).

CONCLUSION

The association of preterm birth with gestational biomarkers of DEHP exposure, but not other phthalate metabolites, differed by the timing of exposure. First and second trimester exposures demonstrated the greatest associations. Our study also highlights methodological considerations for critical periods of susceptibility analyses in pooled studies.

Phthalates and Non-Phthalate Plasticizers and Thyroid Dysfunction: Current Evidence and Novel Strategies to Reduce Their Spread in Food Industry and Environment

Thyroid hormones (THs) play a crucial role in various biological functions, including metabolism, cell growth, and nervous system development, and any alteration involving the structure of the thyroid gland and TH secretion may result in thyroid disease. Growing evidence suggests that phthalate plasticizers, which are commonly used in a wide range of products (e.g., food packaging materials, children's toys, cosmetics, medical devices), can impact thyroid function, primarily affecting serum levels of THs and TH-related gene expression. Like phthalate compounds, recently introduced alternative plasticizers can leach from their source material into the environment, particularly into foods, although so far only a very limited number of studies have investigated their thyroid toxicity. This review aimed at summarizing the current knowledge on the role of phthalate and non-phthalate plasticizers in thyroid dysfunction and disease, describing the major biological mechanisms underlying this relationship. We will also focus on the food industry as one of the main players for the massive spread of such compounds in the human body, in turn conveyed by edible compounds. Given the increasing worldwide use of plasticizers and the essential role of THs in humans, novel strategies should be envisaged to reduce this burden on the thyroid and, in general, on human health.

Association of maternal prenatal phthalate exposure and genetic polymorphisms of metabolic enzyme genes with spontaneous preterm birth: a nested case-control study in China

BACKGROUND

The relationship between prenatal phthalate exposure and preterm birth from previous studies has been inconsistent. Meanwhile, few studies have explored the relationship between spontaneous preterm birth (SPTB) and genetic polymorphisms of metabolic enzyme genes or gene-phthalate interactions. The aim of this study is to evaluate the association of maternal phthalate exposure, genetic polymorphisms, and their interactions with SPTB.

METHODS

A total of 182 cases with SPTB and 321 controls with full-term delivery were enrolled. Nine phthalate metabolites in maternal second trimester urine samples were measured by ultra-high performance liquid chromatography coupled with tandem mass spectrometry. Genotyping was performed on twenty-six single nucleotide polymorphisms (SNPs) of metabolic enzyme genes, including CYP2C9, CYP2C19, UGT1A7, UGT2B7 and UGT2B15 genes. The associations between maternal phthalate exposure or genetic polymorphisms and SPTB were estimated by multivariable logistic regression analysis. The impact of interactions between gene-gene and gene-phthalate exposure on SPTB were analyzed via generalized multifactor dimensionality reduction.

RESULTS

There were no significant differences in the concentrations of phthalate metabolites between the two groups. No statistically significant associations were observed between maternal phthalate exposure and SPTB. The rs4244285 polymorphism of CYP2C19 gene was associated with decreased odds of SPTB under the log-additive (aOR = 0.73, 95% CI: 0.55-0.98) and recessive model (aOR = 0.37, 95% CI: 0.18-0.74). Two SNP loci of UGT2B15 were associated with increased odds of SPTB under the recessive genetic model (aOR = 3.85, 95% CI: 1.31-11.35 for rs3100, and aOR = 3.85, 95% CI: 1.31-11.35 for rs4148269). However, these associations were not significant after the false discovery rate correction. No significant gene-gene or gene-phthalate metabolites interactions for SPTB were observed.

CONCLUSIONS

Maternal phthalate exposure in the present subjects and genetic polymorphisms of metabolic enzyme genes were not associated with SPTB. Moreover, there were no significant gene-gene or gene-phthalates interactions for SPTB.

The role of lifestyle in the impact of constant phthalate exposure on overweight and obesity: A longitudinal cohort study in China

BACKGROUND AND OBJECTIVES

To explore the relationship between constant exposure to phthalates (PAEs) and overweight/obesity and the role of lifestyle in children.

METHODS

This study conducted five repeated follow-up visits with 829 children and analysed data from 740 children. Logistic regression models were used to evaluate the association between constant PAE exposure, lifestyle and overweight/obesity.

RESULTS

The study found that constant high levels of PAEs exposure may increase the risk of obesity in girls, and the risk is higher in girls with an unhealthy lifestyle. In the unhealthy lifestyle group of girls, compared with the constant low (CL) exposure group of PAEs, the odds ratios (ORs) for overweight/obesity and obesity in the constant high (CH) exposure group were 2.99 (1.11, 8.05) and 11.58 (1.38, 96.87), respectively. In addition, an interaction effect between constant exposure to PAEs and lifestyle was observed on obesity in girls.

CONCLUSION

These results suggest the importance of reducing constant exposure to high levels of PAEs to reduce the risk of obesity, especially in individuals with unhealthy lifestyles. The government should strengthen the formulation of regulations and standards for PAEs while guiding parents to use fewer plastic products.

Down-regulation of TET2 inhibits testosterone synthesis in offspring mice exposed to DBP during pregnancy through LH/cAMP/PKA/StAR signaling mediated by LHR

Exposure to di-n-butyl phthalate (DBP) during embryo development or lactation has been linked to reproductive toxicity. The ten-eleven translocation (TET) protein family plays a role in various pathological processes; however, its involvement in reproductive dysfunction in offspring mice exposed to DBP during gestation remains sparsely reported. In this study, SPF C57BL/6 pregnant mice were intragastrically administered DBP at doses of 0.5, 5, and 75 mg/kg body weight, or corn oil as a control, from gestational days 5-19. Following weaning, the offspring mice were maintained on a standard diet for 5 weeks. Additionally, mono-n-butyl phthalate (MBP)-induced TM3 cells were utilized to explore the underlying mechanisms in vitro. The results showed that in utero exposure to DBP resulted in diminished sperm quality, testicular damage, decreased reproductive hormone levels, and reduced expression of testosterone synthesis proteins in male offspring mice. Moreover, DBP exposure influenced the expression of steroidogenic acute regulatory protein (StAR) via the cAMP/PKA signaling pathway, associated with luteinizing hormone receptor (LHR)-mediated suppression of testosterone synthesis. Notably, DBP exposure led to decreased expression of TET methylcytosine dioxygenase 2 (TET2) in the progeny, and overexpression or silencing of TET2 affected the levels of proteins involved in the LHR-mediated testosterone synthesis pathway. Further investigations revealed that TET2 downregulation inhibits testosterone synthesis through the LHR-mediated LH/cAMP/PKA/StAR signaling pathway, ultimately impairing reproductive function in DBP-exposed offspring mice during gestation. This study provides a novel perspective for identifying molecular markers that may be more sensitive indicators of male reproductive damage from an epigenetic standpoint.

Mechanisms and targeted prevention of hepatic osteodystrophy caused by a low concentration of di-(2-ethylhexyl)-phthalate

Objectives

Hepatic osteodystrophy (HOD) is an important public health issue that severely affects human health. The pathogenesis of HOD is complex, and exposure to environmental pollutants plays an important role. Di-(2-ethylhexyl) phthalate (DEHP) is a persistent environmental endocrine toxicant that is present in many products, and the liver is an important target organ for its toxic effects. Our research aimed to investigate the effects of DEHP on HOD, and to reveal the underlying mechanisms and the potential key preventive approaches.

Methods

The daily intake EDI of DEHP and bone density indicators for men and women from 2009 to 2018 were screened and organized from the NHANES database to reveal the population correlation between EDI and BMD; C57BL/6 female and male mice were selected to construct an animal model of DEHP induced HOD, exploring the fuchtions and mechanisms of DEHP on osteoporosis; the novel small molecule inhibitor imICA was used to inhibit the process of DEHP induced osteoporosis, further exploring the targeted inhibition pathway of DEHP induced HOD.

Results

Male and female populations were exposed to a relatively lower concentration of DEHP, and that only the male population exhibited a negative correlation between DEHP exposure and bone mineral density. An in vivo study confirmed that a low dose of DEHP caused liver lesions, disrupted liver function, and induced osteoporosis in male but not female C57BL/6J mice. Regarding the molecular mechanisms, a low dose of DEHP activated the hepatic 14-3-3η/nuclear factor κB (NF-κB) positive feedback loop, which in turn modified the secretory proteome associated with bone differentiation, leading to HOD. Finally, we revealed that targeting the 14-3-3η/ NF-κB feedback loop using our novel 14-3-3η inhibitor (imICA) could prevent DEHP-induced HOD.

Conclusion

A low dose of DEHP activated the hepatic 14-3-3η/ NF-κB positive feedback loop, which in turn modified the secretory proteome associated with bone differentiation and elevated IL-6 and CXCL1 levels, leading to HOD. Targeted 14-3-3η/NF-κB feedback loop using our novel 14-3-3η inhibitor, imICA, prevented DEHP-induced HOD.

Proteomic analysis reveals the alleviation of follicular development defects in offspring mice under DEHP exposure by melatonin

BACKGROUND

Environmental endocrine disruptor Di (2-ethylhexyl) phthalate (DEHP) widely affects the health of human and animals including the reproductive system. However, there are few studies on the protective strategies for the maternal DEHP exposure on follicular development of offspring. In the present study, we established a model of lactation female mice exposed to DEHP and reported the effects and potential mechanism of melatonin on the follicular development of offspring.

RESULTS

Our data showed that melatonin rescued the decrease of primordial follicles, antral follicles and oocyte number (increased by 74.2%) of offspring caused by maternal DEHP exposure from the primordial follicle formation stage. Proteomic analysis showed that melatonin altered the ovarian steroidogenesis, lipid metabolism, signal transduction, and DNA damage-related proteins. Melatonin reversed the disorder of lipid metabolism caused by DEHP and stabilized ovarian hormone secretase level. Molecular docking results indicated that DEHP/MEHP/melatonin binds to HSD17B2 to form a stable conformation, which may explain the reduction in 17β-estradiol induced by DEHP. Moreover, melatonin restored granulosa cell proliferation, reduced oxidative stress and DNA damage-related apoptosis, enhanced mitochondrial function, and protected ovarian cells. Besides, melatonin enhanced gap junction and promoted intercellular communication, which facilitate the formation of primordial follicles and the growth and development of antral follicles. In addition, melatonin rescued the oocyte defects of offspring caused by maternal DEHP exposure.

CONCLUSIONS

Taken together, our data showed that melatonin could alleviate the damage of follicular development and abnormal ovarian steroidogenesis of offspring caused by maternal DEHP exposure.

Fetal exposure to phthalates and body mass index from infancy to adolescence. The Generation R study

Prenatal exposure to phthalates might influence the development of childhood obesity. Most previous studies used body mass index (BMI) at a specific age instead of BMI development, which might be a better indicator of later health. We aimed to assess the association of prenatal phthalate exposure with longitudinal BMI development from infancy to adolescence. Among 1,379 mother-child pairs from a population-based cohort study, phthalate concentrations were measured in maternal spot urine samples, collected during first, second and third trimester. We estimated age- and sex-adjusted BMI standard deviation scores (SDS) at 6 months and 1, 2, 3, 4, 6, 10 and 13 years. We examined the associations of maternal phthalate urine concentrations during pregnancy with repeated measures of BMI using linear mixed effects models. An interquartile range higher natural log-transformed maternal first trimester high-molecular weight phthalate and di-2-ethylhexylphthalate (DEHP) urine concentrations were associated with a -0.10 (95% confidence interval (CI) -0.15 to -0.04), and -0.09 (95% CI -0.15 to -0.04) lower age- and sex-adjusted BMI at 6 months. An interquartile range higher natural log-transformed maternal first trimester phthalic acid and low-molecular weight phthalate urine concentrations were associated with a 0.11 (95% CI 0.03 to 0.18) and 0.13 (95% CI 0.04 to 0.21) higher age- and sex-adjusted BMI at 13 years old. No significant associations were observed for maternal second and third trimester phthalate urine concentrations with BMI. Thus, higher maternal phthalate metabolites urine concentrations appear to be related to lower BMI at early ages but with higher BMI at later ages.

Review of non-invasive biomarkers as a tool for exposure characterization in human health risk assessments

Blood and urine are historically the most frequent matrices used for measuring chemical levels in human biomonitoring studies. As biomonitoring programs are refreshed, consideration of specific priority substances and specific population targets provide opportunities for inclusion of alternative non- or minimally invasive matrices. This review describes methods used in health risk assessment to characterize exposure and risk based upon biomarkers from noninvasive matrices other than urine or blood, including human milk, hair, fingernails, toenails, exhaled breath, deciduous teeth, sweat, semen, meconium, and feces. Illustrative examples of these methods relevant to chemical management are provided. This review suggests that, although these alternative noninvasive biomarkers are not frequently used in human health risk assessment at present, these biomarkers may prove useful in (1) characterizing exposure and health risk in vulnerable populations, (2) cumulative risk assessments, and (3) community-based risk assessments, depending upon the substance of concern. To incorporate alternative noninvasive biomarkers into human health risk assessments with confidence, more research is needed to improve our knowledge of the relationships between external dose, internal dose, and biologic consequent effects in matrices other than blood and urine.

Protective effects of black ginseng on testicular toxicity induced by Di-n-butyl phthalate in rats

Di-n-butyl phthalate (DBP) is a phthalate-based material used as a plasticizer to soften polyvinyl chloride, and classified as an endocrine disruptor with antiandrogen effects. Exposure to DBP induces oxidative stress in rat testes, resulting in testicular toxicity. Black ginseng (BG) exhibits a higher antioxidant activity than white or red ginseng following repeated heat treatment and processing. This study aimed to investigate whether the antioxidant activity of BG might protect against DBP-induced testicular toxicity in juvenile Sprague-Dawley rats. A significant decrease in testicular weight was observed in most groups treated with DBP alone or in combination with BG. However, a significant testicular weight increase was detected after exposure to BG (10 ml/kg) + DBP (500 mg/kg). The epididymal weight was significantly reduced with associated histological changes including irregular arrangement, atrophy of seminiferous tubules and Sertoli cells, and Leydig cell damage following exposure to DBP alone as well as BG (2.5 ml/kg) + DBP (500 mg/kg). However, no marked changes were observed in the shape of seminiferous tubules in control and BG + DBP groups. A significant decrease in serum testosterone levels was found after exposure to DBP, but no marked alterations in the BG + DBP groups. Protein expression levels of nuclear factor erythroid-derived 2-related factor (Nrf2), NAD(P)H dehydrogenase 1 (NQO1), and, heme oxygenase-1; (HO-1) were significantly higher following DBP treatment, but lowered in the BG + DBP groups. Evidence indicates that BG exerts a protective effect against DBP-induced testicular toxicity in rats.

Mechanistic and structural insights into EstS1 esterase: A potent broad-spectrum phthalate diester degrading enzyme

Phthalate diesters are important pollutants and act as endocrine disruptors. While certain bacterial esterases have been identified for phthalate diesters degradation to monoesters, their structural and mechanistic characteristics remain largely unexplored. Here, we highlight the potential of the thermostable and pH-tolerant EstS1 esterase from Sulfobacillus acidophilus DSM10332 to degrade high molecular weight bis(2-ethylhexyl) phthalate (DEHP) by combining biophysical and biochemical approaches along with high-resolution EstS1 crystal structures of the apo form and with bound substrates, products, and their analogs to elucidate its mechanism. The catalytic tunnel mediates entry and exit of the substrate and product, respectively. The centralized Ser-His-Asp triad performs catalysis by a bi-bi ping-pong mechanism, forming a tetrahedral intermediate. Mutagenesis analysis showed that the Met207Ala mutation abolished DEHP binding at the active site, confirming its essential role in supporting catalysis. These findings underscore EstS1 as a promising tool for advancing technologies aimed at phthalate diesters biodegradation.

Basics of utilizing NH4+ ions for accurate phthalate ester quantification via selected ion flow tube mass spectrometry in food

Phthalate esters, frequently used as plasticizers in consumer products, raise concerns because of potential health effects. Using density functional theory (DFT) with B3LYP and 6-311++G(d, p) basis sets, their properties, such as dipole moment, polarizability, proton affinity and ionization energy of phthalate esters are obtained. Reaction kinetics and thermodynamics of popular reagent ions like H3O+ , NH4 + , NO+ and O2 + ∙ are computed to know the feasibility of the reactions with such ions. Proton affinity and ionization energy indicate high susceptibility to proton and charge transfer reactions. High dipole moments contribute to elevated rate coefficients in proton transfer reaction mass spectrometry (PTR-MS) and selected ion flow tube mass spectrometry (SIFT-MS). PTR-MS rates are influenced by drift tube conditions, supported by high center-of-mass collisional energy of Ecm = 0.28 eV. SIFT-MS rates diminish with rising temperature. The high kinetic energy data of H3O+ , NO+ and O2 + ∙ suggests that simple proton transfer and charge transfer reactions are overruled due to very high internal energy which could lead to extensive fragmentation of phthalate esters. The energetic profile of NH4 + ions indicates their suitability for quantifying phthalate esters using NH4 + -CI-MS techniques.

Modulation effects of folic acid and vitamin D on the relationships between prenatal cumulative phthalate exposure and preschoolers' emotional and behavioral problems

BACKGROUND

The results of current population-based studies exploring the effects of prenatal phthalate exposure on children's behavioral problems are not completely consistent. In addition, it is not clear whether vitamins improve phthalate-induced health risks.

METHODS

This study was based on the Ma'anshan Birth Cohort, which included 2910 mother-child pairs. To assess children's behavior, we used the Strengths and Difficulties Questionnaire (SDQ). A latent category growth model was used to model the scores of each subscale of the SDQ. Quantile g-computation and Bayesian kernel machine regression were applied to analyze the effect of prenatal cumulative phthalate exposure.

RESULTS

Prenatal cumulative phthalate exposure was associated with the "borderline and abnormal emotional symptoms" trajectory (β = 0.146, 95 % CI = -0.0003, 0.292), affecting girls more in emotional areas, and boys in conduct areas. There was an interaction effect between folic acid supplementation, vitamin D levels and phthalate mixtures on the risk of abnormal emotional behavior in children, which was reflected mainly in prosocial behavior and conduct problems.

CONCLUSIONS

Prenatal cumulative phthalate exposure increased the risk of abnormal emotional symptoms in children, and there were sex differences. The duration of folic acid supplementation and vitamin D level can affect the effects of cumulative phthalate exposure on emotion and behavior.

Expanding PFAS Identification with Transformation Product Libraries: Nontargeted Analysis Reveals Biotransformation Products in Mice

Per- and polyfluoroalkyl substances (PFAS) are widely used persistent synthetic chemicals that have been linked to adverse health effects. While the behavior of PFAS has been evaluated in the environment, our understanding of reaction products in mammalian systems is limited. This study identified biological PFAS transformation products and generated mass spectral libraries to facilitate an automated search and identification. The biological transformation products of 27 PFAS, spanning 5 chemical subclasses (alcohols, sulfonamides, carboxylic acids, ethers, and esters), were evaluated following enzymatic reaction with mouse liver S9 fractions. Four major pathways were identified by liquid chromatography-high-resolution mass spectrometry: glucuronidation, sulfation, dealkylation, and oxidation. Class-based fragmentation rules and associated PFAS transformation product libraries were generated and integrated into an automated nontargeted PFAS data analysis software (FluoroMatch). Fragmentation was additionally predicted for the potential transformation products of more than 2,500 PFAS in the EPA CompTox Chemicals Dashboard PFASSTRUCTv4. Generated mass spectral libraries were validated by applying FluoroMatch to a data set of urine from aqueous film-forming foam (AFFF)-dosed mice. Toxicity predictions showed identified PFAS transformation products to be potential developmental and mutagenic toxicants. This research enables more comprehensive PFAS characterization in biological systems, which will improve the assessment of exposures and evaluation of the associated health impacts.

Chromogenic Photonic Crystal Detectors for Monitoring Small Molecule Diffusion at Solid-Solid Interfaces Using Stimuli-Responsive Shape Memory Polymers

In situ monitoring of small molecule diffusion at solid-solid interfaces is challenging, even with sophisticated equipment. Here, novel chromogenic photonic crystal detectors enabled by integrating bioinspired structural color with stimuli-responsive shape memory polymer (SMP) for detecting trace amounts of small molecule interfacial diffusion are reported. Colorless macroporous SMP membranes with deformed macropores can recover back to the "memorized" photonic crystal microstructures and the corresponding iridescent structural colors when triggered by diffused small molecules. Systematic experimental and theoretical investigations using various microscopes, optical spectroscopy and modeling, spatio-resolved energy-dispersive X-ray spectroscopy, and theoretical diffusion calculations confirm the diffusion-induced shape memory and chromogenic mechanisms. Importantly, proof-of-concept sensing of temporospatial-resolved diffusion of bioactive ingredients used in drug delivery, including anti-inflammatory methyl salicylate in pain relieving patches and vitamin E barriers loaded in contact lens, and phthalates plasticizers in commercial PVC products has been demonstrated. These innovative detectors are inexpensive, reusable, and easy to operate and deploy for both qualitative and quantitative analyses, promising for opening new avenues in biomedical research, threat detection, and monitoring of plastics, food, and environmental safety. Moreover, reconfigurable photonic crystals with micrometer-scale resolution, which are of great importance in tunable and integrated nanooptics, can be fabricated by diffusion-enabled microcontact printing.

Molecular Mechanisms of Phthalate-Induced Hepatic Injury and Amelioration by Plant-Based Principles

Phthalates are the emerging environmental toxicants derived from phthalic acid and its constituents, which are moderately present in plastics and many personal care products. Phthalate exposure occurs through various environmental factors, including air, water, and soil, with absorption facilitated via ingestion, inhalation, and dermal contact. Upon exposure, phthalates become bioavailable within the biological systems and undergo biotransformation and detoxification processes in the liver. The physicochemical properties of phthalates indicate their lipophilicity, environmental persistence, and bioaccumulation potential, influencing their absorption, distribution, and hepatic biotransformation. The prolonged exposure to phthalates adversely influences the biological redox system by altering the levels of the enzymatic and non-enzymatic antioxidants, molecular signaling pathways, and causing hepatic pathogenesis. The strategies to combat phthalate-induced toxicity include avoiding exposure to these compounds and using plant-based bioactive molecules such as polyphenols, which possess therapeutic potential as antioxidants, suppress inflammatory cascades, prevent oxidative damage, and stabilize cellular integrity. This review presents a comprehensive and updated account of the chemical, biochemical, immunological, and toxicological properties of phthalates, along with novel plant-based therapeutic strategies to mitigate the phthalate-induced adverse effects on living systems.

[Determination of eight phthalate metabolites in urine of pregnant women and evaluation of neonatal birth outcomes based on solid-phase extraction-high performance liquid chromatography-tandem mass spectrometry]

Phthalates (PAEs) are endocrine-disrupting chemicals that are widely present in everyday life and enter the human body through various pathways. The release of PAEs into the environment through pathways that include leaching, evaporation, abrasion, and the use of personal care products exposes humans to PAEs via ingestion, inhalation, and dermal absorption. Pregnant women, as a particularly vulnerable population, risk adverse newborn growth and development when exposed to PAEs. While the concentrations of PAEs in urine reflect recent exposure levels in humans, urinary levels of phthalate metabolites (mPAEs) are commonly used as biomarkers of internal exposure owing to the relatively short biological half-lives of PAEs (<24 h). In this study, we developed a solid-phase extraction-high performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS/MS) method for simultaneously detecting eight mPAEs in the urine of pregnant women. Urine samples were enzymatically hydrolyzed with β-glucosidase and then purified using the Bond Elut Plexa SPE column, with subsequent elution, concentration, and redissolved performed prior to HPLC-MS/MS. Separation was achieved using an Agilent Eclipse Plus C18 column (100 mm×3 mm, 3.5 μm), with gradient elution performed using 0.1% acetic acid aqueous solution and 0.1% acetic acid acetonitrile as mobile phases. Multiple reaction monitoring (MRM) mode was used for detection, with quantification performed using the internal-standard method. Good linearities were obtained in the range of 0.1-200 ng/mL for the eight mPAEs, with limits of detection (LODs) and quantification (LOQs) of 0.015-0.048 and 0.050-0.160 ng/mL, respectively. The eight mPAEs exhibited recoveries of 80.2%-99.7% at three spiked levels (1, 10, and 50 ng/mL). This method was subsequently used to analyze the eight mPAEs levels in urine samples of 497 pregnant women from the Ezhou Maternity and Child Health Care Hospital. The participants exhibited widespread exposure to PAEs, with monobutyl phthalate (MBP) showing the highest median level of 104.46 ng/mL, and monobenzyl phthalate (MBzP) showing the lowest (0.22 ng/mL). In addition, this study assessed neonatal birth outcomes. Linear regression modeling revealed that gestational age decreased by 0.11 weeks (95% confidence interval (CI): -0.18--0.03) for every natural-log (ln) increase in the level of monoethyl phthalate (MEP) in urine samples of pregnant woman. Moreover, the birth weight decreased by 39.28 g (95% CI: -76.48--2.09) and 39.62 g (95% CI: -73.73--5.52), for every ln increase in mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono(2-ethylhexyl) phthalate (MECPP) levels, respectively. The developed method is characterized by its simplicity, low LODs, high accuracy, and precision. This study provides clear evidence that PAE exposure during pregnancy negatively affects newborn growth and development by measuring the levels of eight mPAEs in the urine of pregnant women and linking these findings to neonatal outcomes. Further large-scale cohort studies are needed to validate these findings, along with mechanistic studies using animal models or in-vitro systems that elucidate the biological pathways through which mPAEs contribute to adverse birth outcomes.

Human biomonitoring health-based guidance values: A case study of the HB2GV Dashboard and DEHP

In 2022, the International Society of Exposure Science (ISES) International Human Biomonitoring (i-HBM) Working Group launched a free, online repository of biomonitoring guidance values referred to as the Human Biomonitoring Health-Based Guidance Value (HB2GV) Dashboard. The goal of the Dashboard is to assist global human biomonitoring data users (e.g., risk assessors, risk managers) and human biomonitoring programs with a readily available compilation of guidance values for the general population. The Dashboard contains approximately 600 HB2GVs for over 150 chemicals or their metabolites. Although there are many different types of HB2GVs, most are Biomonitoring Equivalents (BEs), Human Biomonitoring (HBM-I and HBM-II) values, or Human Biomonitoring Guidance Values (HBM-GVs). For users new to human biomonitoring, understanding how the different types of HB2GVs are derived and how to interpret those values in the context of human biomonitoring data can be difficult. Therefore, there is a need to inform users of the differences among available guidance values and to help users identify the HB2GV that could be most suitable for their purposes. Here, we summarize the derivation of HB2GVs for a case study chemical, di-(2-ethylhexyl) phthalate (DEHP). We selected DEHP as there are 36 unique HB2GVs available from three of the most common types of guidance values (i.e., BE, HBM-I value, HBM-GV). We also compare the available HB2GVs with a focus on the differences among their derivation methods, relative quality and confidence, and interpretation. This case study provides guidance on the use of existing HB2GVs for health-based interpretation of human biomonitoring data that may be applied to other chemicals. As with any other type of guidance or regulatory value (e.g., RfDs, MRLs), thoughtful selection and use are strongly encouraged. Appropriately interpreting HBM data with the aid of guidance values can result in improved decision making which, ultimately, could lead to better protection of public health.

In vivo, in vitro, and in silico approaches in the detailed study of di-butyl phthalate (DBP), a plasticizer-induced lung fibrosis via Nrf-2/Keap-1/HO-1 pathway and its regulation

The alveolar epithelium is a crucial barrier against external threats, yet it becomes a key player in initiating pulmonary fibrosis when compromised. Despite its importance, the intricate relationship between, DBP exposure and alveolar epithelial cell injury ensuing pro-fibrotic effects remains poorly understood. Phthalates, ubiquitous in nature, pose a significant risk to lung health upon inhalation, acting as immune triggers that cause airway inflammation and epithelial damage. We aimed to investigate the impact of intranasal administration ofDi-butyl Phthalate (DBP) inhalation, and its probable effects on normal and asthmatic lungs. DBP was administered via intranasal route in normal and OVA-induced asthmatic mice. DBP exposure enhanced oxidative stress and inflammatory parameters, leading to exacerbated asthmatic response and oxidative lung damage. Enhanced accumulation of immune cells, bronchial thickening, and collagen deposition was noted in histopathological investigations of DBP-exposed lung sections. Curcumin, a plant-derived molecule, significantly mitigated DBP-exposed asthma exacerbations by suppressing NF-κB expression and enhancing NRF2 levels via the Nrf-2/Keap-1/HO-1 signaling pathway. FACS analysis revealed increased CD11b+ cells (32 %) in asthmatic mice which were reduced in the curcumin pre-treatment group (10.5 %). Enhanced epithelial to mesenchymal transition (EMT) was noted in mice lungs and A549 cells where E-cadherin expression was reduced as compared to Vimentin, and α-SMA. Apart from aggravated airway inflammation, DBP exposure damages healthy lungs also. MMP-9/TIMP-1 ratios and collagen-1 levels were restored which were enhanced after DBP exposure. Moreover, antioxidant enzyme levels such as NQO-1, HO-1, and Catalase were significantly enhanced (p < 0.01) and comparable to dexamethasone, a conventional corticosteroid. Notably, both dexamethasone and curcumin treatments effectively regulated the stimulation and accumulation of Nrf-2 in the nucleus, promoting antioxidant production and offering potential therapeutic benefits in mitigating pulmonary fibrosis. OVA and DBP alone caused DNA damage in the lung cells where increasedpercentage of damaged DNA movement in thetail, tail length, tail moment, and olive tail moment indicated severe damage in theDBP and OVA combined exposure strategies. Dexamethasone and Curcumin treatments reduced theextent of the DNA damage indicating anti-inflammatory and ant-oxidative potentials. Moreover, in silico studies are supportive of therapeutic potential of Curcumin and Dexamethasone in DBP-induced lung inflammation and fibrosis.

Prenatal Exposure to Dibutyl Phthalate and Its Negative Health Effects on Offspring: In Vivo and Epidemiological Studies

Dibutyl phthalate (DBP) is a low-molecular-weight phthalate commonly found in personal care products, such as perfumes, aftershaves, and nail care items, as well as in children's toys, pharmaceuticals, and food products. It is used to improve flexibility, make polymer products soft and malleable, and as solvents and stabilizers in personal care products. Pregnancy represents a critical period during which both the mother and the developing embryo can be significantly impacted by exposure to endocrine disruptors. This article aims to elucidate the effects of prenatal exposure to DBP on the health and development of offspring, particularly on the reproductive, neurological, metabolic, renal, and digestive systems. Extensive research has examined the effects of DBP on the male reproductive system, where exposure is linked to decreased testosterone levels, reduced anogenital distance, and male infertility. In terms of the female reproductive system, DBP has been shown to elevate serum estradiol and progesterone levels, potentially compromising egg quality. Furthermore, exposure to this phthalate adversely affects neurodevelopment and is associated with obesity, metabolic disorders, and conditions such as hypospadias. These findings highlight how urgently stronger laws prohibiting the use of phthalates during pregnancy are needed to lower the risks to the fetus's health and the child's development.

Associations of maternal and paternal preconception and maternal pregnancy urinary phthalate biomarker and bisphenol A concentrations with offspring autistic behaviors: The PEACE study

BACKGROUND

Environmental chemical exposures in utero may play a role in autism development. While preconception risk factors for autism are increasingly being investigated, little is known about the influence of chemical exposures during the preconception period, particularly for paternal exposures.

METHODS

In 195 children from the Preconception Environmental exposures And Childhood health Effects (PEACE) cohort born to parents recruited from a fertility clinic in Boston, Massachusetts between 2004 and 2017, we quantified concentrations of 11 phthalate metabolites and bisphenol A (BPA) in urine samples collected from mothers and fathers before conception and mothers throughout pregnancy. When children were 6-15 years old, parents completed the Social Responsiveness Scale (SRS) questionnaire assessing autistic behaviors. We used linear mixed effect models to estimate covariate-adjusted associations of phthalate biomarker and BPA concentrations, separately for maternal preconception (n = 179), paternal preconception (n = 121), and maternal pregnancy (n = 177), with SRS T-scores, based on age and gender, in offspring. We used quantile g-computation models for mixture analyses and evaluated modification by selected dietary factors.

RESULTS

The mean SRS T-score was 47.7 (±7.4), lower than the normative mean of 50. In adjusted models for individual biomarkers or mixtures, few associations were observed and estimates were generally negative (e.g., lower SRS T-scores) and imprecise. We observed associations of higher mono-isobutyl phthalate (MiBP) concentrations measured in maternal preconception and paternal preconception periods with lower SRS T-scores (βmaternal_precon = -1.6, 95% CI -2.7; -0.4; βpaternal_precon = -2.9, 95% CI -4.6; -1.2) for each loge increase. In a subset of participants with maternal preconception nutrition information, we generally observed stronger inverse associations with higher folate and iron intake, particularly for folate intake and MiBP concentrations.

CONCLUSIONS

Urinary phthalate biomarker and BPA concentrations during preconception (maternal and paternal) and pregnancy (maternal) were not associated with adverse autistic behaviors in these children. Larger studies are needed to elucidate the observed associations, while considering interactions between maternal nutrition and chemical exposures.

Di(2-ethylhexyl) phthalate disrupts circadian rhythm associated with changes in metabolites and cytochrome P450 gene expression in Caenorhabditis elegans

The plasticizer di(2-ethylhexyl) phthalate (DEHP) is a widespread environmental pollutant due to its extensive use. While circadian rhythms are inherent in most living organisms, the detrimental effects of DEHP on circadian rhythm and the underlying mechanisms remain largely unknown. This study investigated the influence of early developmental exposure to DEHP on circadian rhythm and explored the possible relationship between circadian disruption and DEHP metabolism in the model organism Caenorhabditis elegans. We observed that DEHP disrupted circadian rhythm in a dose-dependent fashion. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed that DEHP-induced circadian disruption accompanies with altered proportions of DEHP metabolites in C. elegans. RNA sequencing data demonstrated that DEHP-induced circadian rhythm disruption caused differential gene expression. Moreover, DEHP-induced circadian disruption coincided with attenuated inductions of DEHP-induced cytochrome P450 genes, cyp-35A2, cyp-35A3, and cyp-35A4. Notably, cyp-35A2 mRNA exhibited circadian rhythm with entrainment, but DEHP exposure disrupted this rhythm. Our findings suggest that DEHP exposure disrupts circadian rhythm, which is associated with changes in DEHP metabolites and cytochrome P450 gene expression in C. elegans. Given the ubiquitous nature of DEHP pollution and the prevalence of circadian rhythms in living organisms, this study implies a potential negative impact of DEHP on circadian rhythm and DEHP metabolism in organisms.

Impact of Endocrine Disruptors on the Genitourinary Tract

Over the last decades, the human species has seen an increase in the incidence of pathologies linked to the genitourinary tract. Observations in animals have allowed us to link these increases, at least in part, to changes in the environment and, in particular, to an increasing presence of endocrine disruptors. These can be physical agents, such as light or heat; natural products, such as phytoestrogens; or chemicals produced by humans. Endocrine disruptors may interfere with the signaling pathways mediated by the endocrine system, particularly those linked to sex hormones. These factors and their general effects are presented before focusing on the male and female genitourinary tracts by describing their anatomy, development, and pathologies, including bladder and prostate cancer.

Adverse effects of diethyl phthalate and butyl benzyl phthalate on circadian rhythms and sleep patterns in zebrafish larvae

The zebrafish, a diurnal vertebrate, is commonly used in circadian rhythm studies due to its genetic and neurological similarities to humans. Circadian rhythms, which regulate sleep, neurotransmitter, behavior, and physiological responses to environmental changes, can be disrupted by various environmental factors. Phthalic acid esters (PAEs) are pervasive endocrine disruptors that individuals are frequently exposed to in daily life. However, the impact of PAEs on circadian rhythms during early development remains poorly understood. This study aimed to investigate the effects of exposure to diethyl phthalate (DEP) and butyl benzyl phthalate (BBzP) on the behavior and circadian rhythms of developing zebrafish larvae using a series of layered assays. Zebrafish larvae were exposed to the two PAEs from less than 2 hour post-fertilization (hpf) until 96 hpf. The results demonstrated a concentration-dependent reduction in tail coiling (TC), touch-evoked response (TER), and locomotor activity, alongside an increase in sleep time and alterations in sleep bouts and sleep latency during both 24-hour and Light1/Dark/Light2 (7/10/7-hour) periods. Additionally, exposure to BBzP led to increased acetylcholinesterase (AChE) and dopamine (DA) levels, and a decrease in 5-hydroxytryptamine (5-HT) levels. Gene expression analysis revealed that DEP and BBzP exposure increased the expression of circadian rhythm and light-response-related genes. In conclusion, exposure to these PAEs disrupts the circadian rhythm of zebrafish larvae, providing novel insights into the developmental impact of these common environmental contaminants. Further research is needed to understand the broader implications of these findings for human health and environmental safety.

In Utero Exposure to Di-n-butyl Phthalate Causes Modulation in Neurotransmitter System of Wistar Rats: A Multigenerational Assessment

Neuroendocrine regulation is disrupted by di-n-butyl phthalate (DBP) when exposure occurs during the critical periods of fetal development, which can lead to neurological disorders. To evaluate the toxic potential of DBP, it is necessary to conduct teratological studies, which could determine impacts on the development of the fetus. The present study was designed to understand the sequelae of neuroendocrine regulation in one-month-old pups when rats were exposed to DBP (F1-F3) in utero and during lactation. The rats received DBP (500 mg/kg BW/day) dissolved in olive oil through oral gavage from gestation day 6 to postnatal day 30, while the control group received the olive oil (vehicle) during the same timeline. Following the exposure, thyroid profile and estradiol, which were measured at GD-19, exhibited a significant decrease (P < 0.05) in dams (F0-F2). The exposure resulted in developmental outcomes, including underdeveloped fetuses, and a notable number of resorptions in experimental rats. The one-month-old pups were assessed for serum thyroid profile and testosterone and neurotransmitters in discrete brain regions, cerebral cortex, cerebellum, and hippocampus for up to three generations. The levels of dopamine and cortisol showed a significant increase (P < 0.05), but serotonin levels decreased when examined in distinct brain regions of the experimental group as compared to the control. DBP, which is considered an endocrine disruptor, had the most impact on the third generation in this study, leading to a significant decrease in testosterone levels. In summary, in utero exposure to DBP impaired the neuroendocrine system and had an antiandrogenic effect in the three successive generations.

Dissolved and particulate phase phthalic acid esters in urban, suburban, and rural riverine catchments along the southeast coast of India after the COVID-19 pandemic

Dumped waste plastics have been evidenced as a potential source for harmful chemicals along the riverine regions of India. Furthermore, Corona Virus Disease - 19 (COVID-19) pandemic resulted in a subsequent surge in the use of personal protective equipment (PPE) related single-use plastics and Tamil Nadu was India's second major waste generator. Given the newer challenges from dumped waste plastics along the four major rivers of Tamil Nadu emptying into the Bay of Bengal, we investigated thirteen phthalic acid esters (PAEs), in both dissolved and particulate phases of river water and drinking water samples. Ʃ13PAEs in both phases followed the urban > suburban > rural catchment trend. Di (2-ethyl hexyl) phthalate (DEHP) was ubiquitous in both phases and the sites having a prevalence of open burning activities in the urban catchment showed elevated levels. The suburban and rural catchments of the Kaveri River (KR) and Thamirabharani River (TR) were predominated by DEP and DEHP. It is noteworthy that in the urban catchment, Ln (DiBP) and dissolved organic carbon (Ln DOC), were strongly correlated (R2 = 0.894, p < 0.05). Furthermore, a significant increase of DiBP (p < 0.05) in the urban catchment after the second phase of the pandemic most likely resulted from the wide use of DiBP in PPE plastics. Community-stored water from urban catchment was found to have a maximum of ∑13PAEs up to 3769.38 ng/L in the dissolved phase with elevated DMP concentrations leading to higher estrogenic equivalent. The average daily intake for dissolved phase PAEs was below the USEPA-recommended limit for drinking water. However, prolonged exposure to heavier PAEs in particulate matter cannot be ignored. Estimated ecotoxicological risk assessment showed the highest risk for fish species due to DEHP.

Di-2-ethylhexyl phthalate (DEHP) exposure increase female infertility

This study explores the relationship between Di-2-ethylhexyl phthalate (DEHP) exposure and female infertility. The analysis included 998 female participants aged between 18 and 44 years. We analyzed data from the National Health and Nutrition Examination Survey (2013-2018) using multiple logistic regression and generalized linear models to assess the impact of DEHP on infertility. Additionally, we employed curve fitting and two-piecewise linear regression models to investigate potential nonlinear correlations, conducting subgroup analyses based on age, BMI, alcohol consumption, smoking status, hypertension, and diabetes. Our results, after adjusting for confounders, revealed a positive association between DEHP exposure and infertility. This association was significant whether DEHP was treated as a continuous variable (odds ratio OR = 1.28, 95 % confidence interval CI: 1.08-1.52, P = 0.0072) or as a categorical variable (P for trend = 0.0038). A non-linear relationship was identified, with an inflection point at - 3.35 (∑DEHP = 0.0981 × 10-9 mol/mg creatinine). Effect sizes were 1.55 (1.01-2.36) on the left side of the inflection point and 0.73 (0.43-1.23) on the right side. Subgroup analysis indicated that the correlation was consistent across stratified variables. In conclusion, our findings suggest a non-linear association between DEHP exposure and female infertility, with a positive correlation within a specific dose range, but no further increase in risk beyond a certain threshold.

Infants exposure to chemicals in diapers: A review and perspective

Diapers are a staple care product for infants, yet concerns persist regarding the potential risks posed by dermal exposure to chemicals through their usage. This review provides a comprehensive summary of reported chemicals, highlighting the frequent detection of polychlorodibenzo-p-dioxins (PCDDs), phthalates (PAEs), volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), bisphenols (BPs), organotins, and heavy metals. Disposable diapers commonly exhibit higher concentrations of VOCs, PAEs, BPs, and heavy metals than other chemicals. Our estimation reveals formaldehyde as posing the highest dermal exposure dose, reaching up to 0.018 mg/kg bw/day. Conversely, perfluorooctanoic acid (PFOA) exhibits lower exposure, but its non-cancer hazard quotient (0.062) is the highest. In most scenarios, the risk of chemical exposure through diapers for infants is deemed acceptable, while the risk is higher under some extreme exposure scenarios. Using the cancer slope factor recently suggested by U.S. EPA, the cancer risk in diapers raised by PFOA is 5.5 × 10-5. It should be noted that our estimation is approximately 1000-10,000 folds lower than some previous estimations. The high uncertainties associated with exposure and risk estimations are primarily raised by unclear parameters related to chemical migration coefficients, absorption factors, concentrations, and toxicity data for skin exposure, which requires research attention in future. Besides that, future research endeavors should prioritize the identification of potential toxic chemicals and the development of hygiene guidelines and standards.

Review of toxicity and global distribution of phthalate acid esters in fish

Organic additives are incorporated during the manufacturing of plastics, and these additives are gradually released into the environment from plastic debris. Among these, phthalate acid esters (PAEs) are the most prevalent. PAEs can be found in the atmosphere, aquatic ecosystems, terrestrial regions, soil, and within animal and human bodies. They are released from industrial activities and have a significant impact on the natural environment. This study reviews research on PAEs from various regions worldwide, with about 47.8 % of the studies published between 2020 and 2024. The highest concentrations of PAEs were detected in fish samples from rivers in Taiwan, ranging from 13.6 to 70.0 mg/kg dry weight. PAEs tend to accumulate more in benthic organisms and sediments. DEHP was the most prevalent PAE in fish samples, showing the highest levels and detection frequency among the analyzed PAEs. Some studies found a strong correlation (r2 = 0.85) between PAEs concentrations in fish and water. The findings of this study can help in assessing the fate and behavior of PAEs in the environment and provide a basis for developing future management strategies to control phthalate acid esters pollution in aquatic environments.

Study of the economic consequences and phthalate emission caused by centralized and decentralized patterns of infectious waste management

The development of health services of hospitals in developing countries has led to a significant increase in the production of infectious waste, which has important economic and environmental consequences. Therefore, reducing pollutant leakage caused by disinfection and reducing infectious waste management costs are important in achieving sustainable development goals in hospital management. In this study, the centralized and decentralized patterns of infectious waste management were studied in three hospitals in Behbahan, Iran. Economic analysis was done based on the financial model. Phthalate emission from disinfection equipment was measured for investigating the level of exposure to the pollutant in the studied patterns. The results showed that the cost of waste transportation for studied hospitals in the centralized patterns increased by 12.1 %. However, reductions in disinfection and transfer costs up to 32.4 % were available by increasing the segregation ratio of infectious waste. The average emission of phthalates from disinfection equipment in the studied hospitals was 0.260 ng/kg. But emission of phthalate types was not the same, so that the emission of BEHP, IBP, and DBP was 35.97, 4.90, and 1.55 μg/m3, respectively. Considering the hospital waste reduction plan and increasing the segregation ratio to reduce the costs of the hospital led to economic justification of the centralized pattern of infectious waste management as a safe option.

Management of phthalates in Canada and beyond: can we do better to protect human health?

Ortho-phthalates (herein referred to as phthalates) are synthetic chemicals used in thousands of different everyday products and materials. Nearly ubiquitous environmental exposure is reflected by phthalate metabolites in the urine of almost all Canadians. However, phthalate exposure tends to be higher amongst people of low socioeconomic status and ethnic minorities. Substantial evidence shows that certain phthalates cause harm to human health, particularly developing fetuses and children. Governments vary in their approach to assessing and managing risks associated with phthalates. Canada continues to take a more permissive stance on phthalate regulations compared to the EU and some US states. We argue that the recent Canadian national risk assessment on phthalates does not appropriately reflect the growing evidence demonstrating harm to human health from phthalate exposure and does not adequately consider the evidence showing higher exposures faced by vulnerable populations. Canadians would benefit from adopting a more stringent regulatory approach to phthalates. Specifically, Canada should expand phthalate restrictions to apply to all consumer products, implement sunset dates toward eliminating the use of existing phthalates, and mandate publicly available evidence of no harm for phthalate alternatives. Canadian alignment on phthalate regulations with the EU and a growing number of US states could encourage other countries to follow suit.

Association of joint exposure to organophosphorus flame retardants and phthalate acid esters with gestational diabetes mellitus: a nested case-control study

BACKGROUND

Organic phosphate flame retardants (OPFRs) and phthalate acid esters (PAEs) are common endocrine-disrupting chemicals that cause metabolic disorders. This study aimed to assess the association between joint exposure to OPFRs and PAEs during early pregnancy in women with gestational diabetes mellitus (GDM).

METHODS

Seven OPFRs and five PAEs were detected in the urine of 65 GDM patients and 100 controls using gas chromatography-tandem triple quadrupole mass spectrometry (GC-MS). The association of OPFRs and PAEs with GDM was assessed using logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models.

RESULTS

Levels of dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DEHP), diethyl phthalate (DEP), dimethyl phthalate (DMP), tris (2-butoxyethyl) phosphate (TBEP), tributyl phosphate (TBP), tris (2-chloroethyl) phosphate (TCEP), tris (1,3-dichloro-2-propyl) phosphate (TDCPP), tri-ortho-cresyl phosphate (TOCP), and triphenyl phosphate (TPHP) increased in the GDM group, and the OPFRs and PAEs, except for BBP and TMCP, were associated with GDM in the logistic regression analysis. In the WQS model, the mixture of OPFRs and PAEs was significantly positively associated with GDM (OR = 3.29, 95%CI = 1.27-8.51, P = 0.014), with TDCPP having the highest WQS index weight. BKMR analysis reinforced these results, showing that the overall association of joint exposure to the OPFRs and PAEs with GDM increased at exposure levels of the 55th to 75th percentiles. Independent exposure to TDCPP (OR = 1.42, 95%CI = 1.09-1.86, P = 0.011) and TBEP (OR = 1.29, 95%CI = 1.04-1.60, P = 0.023) were associated with an increased risk of GDM.

CONCLUSIONS

Environmental exposure to OPFRs and PAEs is significantly associated with GDM. These findings provide evidence for the adverse effects of exposure to OPFRs and PAEs on the health of pregnant women.

Lycium barbarum polysaccharide alleviates ferroptosis in Sertoli cells through NRF2/SLC7A11/GPX4 pathway and ameliorates DEHP-induced male reproductive damage in mice

Di-(2-ethylhexyl)phthalate (DEHP) is a common plasticizer that has been shown to significantly negatively affect male reproductive health. On the other hand, Lycium barbarum polysaccharide (LBP) has been shown to improve reproductive function. Therefore, we hypothesized that LBP may ameliorate DEHP-induced male reproductive damage. Herein, we found that LBP could alleviate DEHP-induced testicular damage and sperm abnormalities. Furthermore, histomorphological analysis of mice testis revealed that LBP primarily ameliorated the DEHP-induced male reproductive damage by targeting Sertoli cells. Moreover, the detection of the function-related genes of Sertoli cells confirmed this finding. The serum of mice in the Control, DEHP, and DEHP+LBP groups was analyzed using non-targeted metabolomics to further elucidate the mechanism of action of LBP in improving DEHP-induced male reproductive damage. According to the results, the differential metabolites were mainly enriched in the glutamate metabolism pathway, implying that LBP may alleviate the ferroptosis-related DEHP-induced testicular injury. Related ferroptosis markers were also found in mice testis. These findings collectively suggest that LBP may ameliorate DEHP-induced testicular injury via alleviating ferroptosis in Sertoli cells. To clarify the specific mechanism, we constructed a cell model in vitro by treating TM4 cells (the Sertoli cell line) with LBP and MEHP (the in vivo DEHP metabolite). Our findings revealed that LBP can improve the function of DEHP-affected Sertoli cells. Furthermore, the analysis of lipid peroxidation, Fe2+ content, and ferroptosis-related protein expressions demonstrated that LBP could ameliorate MEHP-induced ferroptosis in TM4 cells. To clarify the specific mechanism, glutamate metabolism-related proteins involved in the ferroptosis pathway were detected. According to the results, there were significant changes in the expression of NRF2, SLC7A11 and GPX4 proteins, which are involved in the ferroptosis glutamate metabolism pathway. Furthermore, supplementation of NRF2, SLC7A11, and GPX4 inhibitors (ML385, Erastin, and RSL3, respectively) blocked the therapeutic effect of LBP in alleviating MEHP-induced ferroptosis in TM4 cells, implying that LBP could also ameliorate MEHP-induced ferroptosis via the NRF2/SLC7A11/GPX4 pathway. In summary, these findings show that LBP can alleviate DEHP/MEHP-induced ferroptosis through the NRF2/SLC7A11/GPX4 pathway, ameliorating Sertoli cell dysfunction and improving the DEHP-induced male reproductive damage. Therefore, the clinical administration of LBP could be an effective strategy for preventing DEHP-induced male reproductive injury.

Liver DE(HP)toxification: luteolin as "phthalates-cleaner" to protect from environmental pollution

A Mengozzi and F Cappelli discuss a potential pharmacological strategy for phthalate detoxification of the liver as reported by S Chen, C Liu, W Zhang and colleagues, in this issue of EMBO Mol Med .

Asking Why Is Necessary to Address Health Disparities: A Critical Approach for Solution-Oriented Environmental Epidemiological Research

BACKGROUND

In environmental epidemiology, we use an array of tools from various, related disciplines to answer key questions about environmental exposures in relation to health outcomes. Typically, we ask questions related to what, who, where, when, and how. We value these questions because they contribute to novel scientific discovery and our understanding of disease etiology linked to environmental exposures. In addition, these questions help us better understand who might be at highest risk of exposure and subsequent risk of disease. Although necessary for the goals of environmental epidemiology, these questions are insufficient for addressing environmental health disparities. Specifically, these questions may be able to help us describe exposure-health outcome associations but are limited in their ability to move beyond identification to intervening on observed disparities to achieve environmental health equity.

OBJECTIVES

We sought to emphasize the need to value and routinely add the key question of "Why?" in environmental epidemiological studies. In asking this additional critical question, we can identify and incorporate the structural determinants and drivers of environmental exposure disparities and determine whether these factors are linked to existing and historically recalcitrant health disparities. Further, we can design effective studies that build on existing frameworks to address the fundamental causes of environmental health disparities.

DISCUSSION

This commentary underscores the need to routinely incorporate "why" questions in the practice of environmental epidemiology. By asking and addressing "Why?" we can employ better, more solution-oriented study designs, improve data collection, and enhance our ability to collaborate with diverse study populations through trust-building and community-engaged research. Incorporating these approaches will move environmental epidemiology forward from mostly documenting to actively addressing environmental health disparities. https://doi.org/10.1289/EHP14513.

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 h in vehicle control, a phthalate mixture, or a phthalate metabolite mixture (0.1 to 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.

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.

Suspect and non-target screening of chemicals of emerging Arctic concern in biota, air and human serum

Contaminants of emerging concern receive increasing attention in the Arctic environment. The aim of this study was to screen for chemicals of emerging Arctic concern (CEACs) in different types of Arctic samples including biota, air and human serum. We used a combination of gas chromatography (GC) and liquid chromatography (LC) with high resolution mass spectrometry (HRMS) for suspect and non-target screening (NTS). Suspect screening of 25 CEACs was based on published in-silico approaches for the identification of CEACs and revealed tetrabromophthalic anhydride (TBPA) in pilot whale and air, albeit with low detection frequencies (17 and 33%, respectively). An NTS workflow detected 49, 42, 31 and 30 compounds in pilot whale, ringed seal, air, and human serum, respectively, at confidence level 2 and 3. Although legacy POPs still dominated the samples, 64 CEACs were tentatively identified and further assessed for persistence (P), bioaccumulation (B), mobility (M), toxicity (T), and long-range transport potential (LRTP). While four PBT compounds were identified, 37 PMT substances dominated among these 64 compounds. Our study indicated that many chemicals of potential risk might be present in Arctic samples and would benefit from confirmation and further studies of their transport to and accumulation in the Arctic environment.

Distinct Impacts of Prenatal and Postnatal Phthalate Exposure on Behavioral and Emotional Development in Children Aged 1.5 to 3 Years

Development is a continuous process, but few studies have assessed the simultaneous impact of prenatal and postnatal phthalate exposure on children's behavioral and emotional development. A total of 491 mother-child pairs from the general population in southern Taiwan were studied from 2021 to 2022. Urinary concentrations of bisphenol A (BPA) and phthalate metabolites-mono-ethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono-benzyl phthalate (MBzP), and mono-2-ethylhexyl phthalate (MEHP)-were measured in pregnant mothers during the second trimester and in their corresponding children aged 1.5 to 3 years. Behavioral symptoms in children were evaluated using the Child Behavior Checklist (CBCL). Odds ratios (ORs) represent a 1-unit increase in log10-transformed creatinine-corrected maternal urine concentrations. Prenatal maternal urinary MnBP levels were associated with total problems (OR = 19.32, 95% CI: 1.80-43.13, p = 0.04), anxiety (OR = 33.58, 95% CI: 2.16-521.18, p = 0.01), and sleep problems (OR = 41.34, 95% CI: 1.04-1632.84, p = 0.04) in children. Additionally, urinary MnBP levels in children correlated with total problems (OR = 7.06, 95% CI: 1.01-49.05, p = 0.04) and internalizing problems (OR = 11.04, 95% CI: 1.27-95.72, p = 0.01). These findings suggest that prenatal and postnatal exposure to dibutyl phthalate (DBP), metabolized as MnBP, distinctly affects children's behavioral development.

Associations of Phthalate Exposure With Adiposity and Metabolic Syndrome in US Adolescents and Adults, NHANES 2013 to 2018

Context

Phthalates are ubiquitous endocrine-disrupting chemicals and suspected obesogens. However, the associations with fat distribution and associated cardiometabolic complications remain unclear.

Objective

We examined the associations between phthalate exposure, body fat (total and distribution patterns), and metabolic syndrome (MetS) among US adolescents and adults.

Methods

We analyzed cross-sectional data from 829 adolescents and 3905 adults in the 2013 to 2018 National Health and Nutrition Examination Survey. Total percentage body fat (%BF), visceral adipose tissue (VAT) mass, and android to gynoid (A/G) ratio were determined using dual-energy x-ray absorptiometry. Associations between molar sums of low molecular weight (∑LMW), high molecular weight (∑HMW), and di(2-ethylhexyl) phthalate (∑DEHP) metabolites, and adiposity indicators and MetS were analyzed with multivariable linear and logistic regressions. Models included sex interaction terms, were stratified by age group, and adjusted for relevant covariates.

Results

∑HMW and ∑DEHP exposures were positively associated with %BF in males, and all phthalate groups were associated with greater VAT mass and A/G ratio in adolescent males. Five-fold increases in ∑HMW and ∑DEHP metabolites were associated with 21.7% (95% CI, 10.5-33.9) and 18.0% (95% CI, 7.72-29.2) greater VAT mass among adolescent males, respectively. Sex modified the relationship between ∑HMW exposure and A/G ratio among adolescents (interaction P value = .0185). Phthalates were not associated with odds of MetS. When assessing individual MetS components, phthalates were associated with hyperglycemia in adult males.

Conclusion

Greater exposure to phthalates was associated with greater %BF in all males, and with fat distribution in adolescent males; however, phthalates were not linked to MetS.

Placental Transcriptomic Signatures of Prenatal Phthalate Exposure and Identification of Placenta-Brain Genes Associated with the Effects of Phthalate Exposure on Neurodevelopment in Children

Prenatal exposure to phthalates may affect placental function and fetal development, but the underlying mechanisms are unclear. The aim of our study was to explore the alterations in the placental transcriptome associated with prenatal phthalate exposure and to further analyze whether the placental-brain axis (PBA) genes play a mediating role in the association between prenatal phthalate exposure and children's neurodevelopment. We included 172 participants from the Ma'anshan Birth Cohort and collected data on seven phthalate metabolites in urine during pregnancy, placental tissue RNA-seq, and neurodevelopment of offspring. Bioinformatics analysis revealed that aberrant regulation of the placental transcriptome was associated with prenatal phthalate exposure. Exposure to phthalates during pregnancy was found to be associated with neurodevelopmental delay in children aged 6, 18, and 48 months using the multiple linear regression model. Meanwhile, employing mediation analysis, nine PBA genes were identified that mediate the association between exposure to phthalates during pregnancy and the neurodevelopment of children. Our study will provide a basis for potential mechanisms by which prenatal exposure to phthalates affects placental function and children's neurodevelopment.

Endocrine-Disrupting Chemicals, Hypothalamic Inflammation and Reproductive Outcomes: A Review of the Literature

Endocrine-disrupting chemicals (EDCs) are environmental and industrial agents that interfere with hormonal functions. EDC exposure is linked to various endocrine diseases, especially in reproduction, although the mechanisms remain unclear and effects vary among individuals. Neuroinflammation, particularly hypothalamic inflammation, is an emerging research area with implications for endocrine-related diseases like obesity. The hypothalamus plays a crucial role in regulating reproduction, and its inflammation can adversely affect reproductive health. EDCs can cross the blood-brain barrier, potentially causing hypothalamic inflammation and disrupting the reproductive axis. This review examines the existing literature on EDC-mediated hypothalamic inflammation. Our findings suggest that exposure to 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD), polychlorinated biphenyl (PCB), tributyltin (TBT), phthalates, bisphenol A (BPA), and chlorpyrifos (CPF) in animals is linked to hypothalamic inflammation, specifically affecting the hypothalamic centers of the gonadotropic axis. To our knowledge, this is the first comprehensive review on this topic, indicating hypothalamic inflammation as a possible mediator between EDC exposure and reproductive dysfunction. Further human studies are needed to develop effective prevention and treatment strategies against EDC exposure.

Urinary metabolite concentrations of phthalate and plasticizers in infancy and childhood in the UNC baby connectome project

INTRODUCTION

Existing evidence suggests that exposure to phthalates is higher among younger age groups. However, limited knowledge exists on how phthalate exposure, as well as exposure to replacement plasticizers, di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) and di-2-ethylhexyl terephthalate (DEHTP), change from infancy through early childhood.

METHODS

Urine samples were collected across the first 5 years of life from typically developing infants and young children enrolled between 2017 and 2020 in the longitudinal UNC Baby Connectome Project. From 438 urine samples among 187 participants, we quantified concentrations of monobutyl phthalate (MnBP), mono-3-carboxypropyl phthalate (MCPP), monoisobutyl phthalate (MiBP), monoethyl phthalate (MEP), monobenzyl phthalate (MBzP), and metabolites of di(2-ethylhexyl) phthalate (DEHP), diisonoyl phthalate (DiNP), DINCH and DEHTP. Specific gravity (SG) adjusted metabolite and molar sum concentrations were compared across age groups. Intraclass correlation coefficients (ICCs) were calculated among 122 participants with multiple urine specimens (373 samples).

RESULTS

Most phthalate metabolites showed high detection frequencies (>80% of samples). Replacement plasticizers DINCH (58-60%) and DEHTP (>97%) were also commonly found. DiNP metabolites were less frequently detected (<10%). For some metabolites, SG-adjusted concentrations were inversely associated with age, with the highest concentrations found in the first year of life. ICCs revealed low to moderate reliability in metabolite measurements (ρ = 0.10-0.48) suggesting a high degree of within-individual variation in exposure among this age group. The first 6 months (compared to remaining age groups) showed an increased ratio of carboxylated metabolites of DEHP and DEHTP, compared to other common metabolites, but no clear age trends for DINCH metabolite ratios were observed.

CONCLUSION

Metabolites of phthalates and replacements plasticizers were widely detected in infancy and early childhood, with the highest concentrations observed in the first year of life for several metabolites. Higher proportions of carboxylated metabolites of DEHP and DEHTP in younger age groups indicate potential differences in metabolism during infancy.

Phthalate exposure as a hidden risk factor for uterine leiomyoma in adult women: Accumulated evidence from observational studies

BACKGROUND

There is evidence that exposure to phthalate in women may increase the risk of uterine leiomyomas. Whereas, the association between exposure to phthalate and the incidence of uterine leiomyoma remained inconclusive.

METHODS

A meta-analysis was performed to evaluate their relationship. Literature eligible for inclusion was found in PubMed, EMBASE, Web of Science, and WanFang Medical Database. Pooled odds ratio (OR) with 95 % confidence interval (CI) was calculated to assess the risk for effect estimate for each phthalate.

RESULTS

A total of fourteen observational studies with 5777 subjects of adult women were included in this study. In the pooled analysis, we found an elevated risk of uterine leiomyoma among women who were exposed to higher levels of di-2-ethylhexyl phthalate (DEHP) (OR 1.61, 95 % CI: 1.18-2.20), as estimated indirectly from the molar summation of its urinary metabolite concentrations. In addition, a positive association was observed between the occurrence of uterine leiomyoma and exposure to low molecular weight phthalate mixture (OR 1.08, 95 % CI: 1.00-1.15), as well as high molecular weight phthalate mixture (OR 1.08, 95 % CI: 1.01-1.15), as quantified by integrating the effect estimates of individual metabolite from each study. Urinary levels of DEHP metabolites, monobenzyl phthalate, mono-(3-carboxypropyl) phthalate, mono-isobutyl phthalate, mono-n-butyl phthalate, monoethyl phthalate, and monomethyl phthalate were not appreciably correlated with the risk of uterine leiomyoma.

CONCLUSION

Our results indicated that exposure to DEHP, and co-exposure to high or low molecular weight phthalate mixture might be potential risk factors for uterine leiomyoma in adult women. Owing to the indirect estimation of association, when interpreting these findings, cautions should be taken.

Urinary phthalate metabolites associated with bone mineral density in adults: Data from the NHANES 2011-2018

Phthalates (PAEs) are common environmental endocrine disruptors and environmental bone poisons that can reduce bone mineral density (BMD). The purpose of this study is to investigate whether the concentration of PAE metabolites in urine is related to BMD in many parts of adult bones. We examined a series of cross-sectional data of male (n = 1835) and female (n = 1756) participants aged 18 to 59 years old in the National Health and Nutrition Examination Survey from 2011 to 2018 and measured urine PAE metabolites and dual-energy X-ray absorption to determine BMD (total body, lumbar spine, and pelvis). We used linear regression to test the correlation between a single phthalate biomarker and BMD. After adjusting all confounding variables, MEHP was positively correlated with BMD of total body, lumbar spine and pelvis, and BMD levels of the total body, lumbar spine and pelvis decreased with the increase of MECPP concentration. We used the restricted cubic spline function to test the nonlinear correlation between PAE biomarkers and BMD. The results show that urinary PAE metabolites have a nonlinear relationship with total body BMD, lumbar spine BMD, and pelvic BMD. With the increase in the PAE concentration, the BMD level first increased and then decreased, showing an inverted U-shaped trend (P < 0.05). Gender stratification also shows the same related trend. PAEs may be related to the BMD of adults. When the concentration of PAEs increases to a certain threshold, it will lead to a significant decrease in BMD.

Silicone wristbands reveal ubiquitous human exposure to ortho-phthalates and non-ortho-phthalate plasticizers in Southern California

In the United States and abroad, ortho-phthalates and non-ortho-phthalate plasticizers continue to be used within a diverse array of consumer products. Prior California-specific biomonitoring programs for ortho-phthalates have focused on rural, agricultural communities and, to our knowledge, these programs have not measured the potential for exposure to non-ortho-phthalate plasticizers. Therefore, the potential for human exposure to ortho-phthalates and non-ortho-phthalate plasticizers have not been adequately addressed in regions of California that have higher population density. Since there are numerous sources of ortho-phthalates and non-ortho-phthalate plasticizers in population-dense, urban regions, the objective of this study was to leverage silicone wristbands to quantify aggregate ortho-phthalate and non-ortho-phthalate plasticizer exposure over a 5-day period across two different cohorts (2019 and 2020) of undergraduate students at the University of California, Riverside (UCR) that commute from all over Southern California. Based on 5 d of aggregate exposure across two different cohorts, total ortho-phthalate plus non-ortho-phthalate plasticizer concentrations ranged, on average, from ∼100,000-1,000,000 ng/g. Based on the distribution of individual ortho-phthalate and non-ortho-phthalate plasticizer concentrations, the concentrations of di-isononyl phthalate (DiNP, a high molecular weight ortho-phthalate), di (2-ethylhexyl) phthalate (DEHP, a high molecular weight ortho-phthalate), and di-2-ethylhexyl terephthalate (DEHT, a non-ortho-phthalate plasticizer) detected within wristbands were higher than the remaining seven ortho-phthalates and non-ortho-phthalate plasticizers measured, accounting for approximately 94-97% of the total mass depending on the cohort. Overall, our findings raise concerns about chronic DiNP, DEHP, and DEHT exposure in urban, population-dense regions throughout California.