Mothers and children are related, even in exposure to chemicals present in common consumer products

Multiomics analysis reveal the impact of 17α-Ethinylestradiol on mortality in juvenile zebrafish

17α-Ethinylestradiol (EE2) is known for its endocrine-disrupting effects on embryonic and adult fish. However, its impact on juvenile zebrafish has not been well established. In this study, juvenile zebrafish were exposed to EE2 at concentrations of 5 ng/L (low dose, L), 10 ng/L (medium dose, M), and 50 ng/L (high dose, H) from 21 days post-fertilization (dpf) to 49 dpf. We assessed their growth, development, behavior, transcriptome, and metabolome. The findings showed that the survival rate in the EE2-H group was 66.8 %, with all surviving fish displaying stunted growth and swollen, transparent abdomens by 49 dpf. Moreover, severe organ deformities were observed in the gills, kidneys, intestines, and heart of fish in both the EE2-H and EE2-M groups. Co-expression analysis of mRNA and lncRNA revealed that EE2 downregulated the transcription of key genes involved in the cell cycle, DNA replication, and Fanconi anemia signaling pathways. Additionally, metabolomic analysis indicated that EE2 influenced metabolism and development-related signaling pathways. These pathways were also significantly identified based on the genes regulated by lncRNA. Consequently, EE2 induced organ deformities and mortality in juvenile zebrafish by disrupting signaling pathways associated with development and metabolism. The results of this study offer new mechanistic insights into the adverse effects of EE2 on juvenile zebrafish based on multiomics analysis. The juvenile zebrafish are highly sensitive to EE2 exposure, which is not limited to adult and embryonic stages. It is a potential model for studying developmental toxicity.

Exposure of elementary school-aged Brazilian children to bisphenol A: association with demographic, social, and behavioral factors, and a worldwide comparison

Bisphenol A (BPA) is a plasticizer used to synthesize polycarbonate plastics and epoxy resins and is well-known for its endocrine-disrupting action. BPA occurrence in the environment is widespread, and there is a growing concern regarding exposure to this chemical during childhood, given the findings indicating the long-lasting hazards associated with exposure during early life compared to adulthood. We examined urinary BPA concentrations from 319 elementary school-aged Brazilian children, using high-performance liquid chromatography coupled to high-resolution mass spectrometry. We found that urinary BPA was detectable in the majority of children, and that urinary BPA levels were higher among children with lower family income and lower maternal educational levels. BPA levels found herein were compared with those from countries with different regulation policies concerning exposure to BPA. They were similar to those reported from studies conducted in Egypt and Australia. Despite more protective regulatory policies in the European Union, they were similar or lower than those reported in European studies. Our findings indicate that exposure of Brazilian children to BPA is widespread and comparable to or even lower than that of countries with stricter regulatory policies.

Impact of Skin Care Products on Phthalates and Phthalate Replacements in Children: the ECHO-FGS

BACKGROUND

Phthalates and their replacements have been implicated as developmental toxicants. Young children may be exposed to phthalates/replacements when using skin care products (SCPs).

OBJECTIVES

Our objective is to assess the associations between use of SCPs and children's urinary phthalate/replacement metabolite concentrations.

METHODS

Children (4-8 years old) from the Environmental Influences on Child Health Outcomes-Fetal Growth Study (ECHO-FGS) cohort provided spot urine samples from 2017 to 2019, and mothers were queried about children's SCP use in the past 24 h (n = 906 ). Concentrations of 16 urinary phthalate/replacement metabolites were determined by liquid chromatography-tandem mass spectrometry (n = 630 ). We used linear regression to estimate the child's use of different SCPs as individual predictors of urinary phthalate/replacement metabolites, adjusted for urinary specific gravity, age, sex assigned at birth, body mass index, and self-reported race/ethnic identity, as well as maternal education, and season of specimen collection. We created self-organizing maps (SOM) to group children into "exposure profiles" that reflect discovered patterns of use for multiple SCPs.

RESULTS

Children had lotions applied (43.0%) frequently, but "2-in-1" hair-care products (7.5%), sunscreens (5.9%), and oils (4.3%) infrequently. Use of lotions was associated with 1.17-fold [95% confidence interval (CI): 1.00, 1.34] greater mono-benzyl phthalate and oils with 2.86-fold (95% CI: 1.89, 4.31) greater monoethyl phthalate (MEP), 1.43-fold (95% CI: 1.09, 1.90) greater monobutyl phthalate (MBP), and 1.40-fold (95% CI: 1.22, 1.61) greater low-molecular-weight phthalates (LMW). Use of 2-in-1 haircare products was associated with 0.84-fold (95% CI: 0.72, 0.97) and 0.78-fold (95% CI: 0.62, 0.98) lesser mono(3-carboxypropyl) phthalate (MCPP) and MBP, respectively. Child's race/ethnic identity modified the associations of lotions with LMW, oils with MEP and LMW, sunscreen with MCPP, ointments with MEP, and hair conditioner with MCPP. SOM identified four distinct SCP-use exposure scenarios (i.e., profiles) within our population that predicted 1.09-fold (95% CI: 1.03, 1.15) greater mono-carboxy isononyl phthalate, 1.31-fold (95% CI: 0.98, 1.77) greater mono-2-ethyl-5-hydroxyhexyl terephthalate, 1.13-fold (95% CI: 0.99, 1.29) greater monoethylhexyl phthalate, and 1.04-fold (95% CI: 1.00, 1.09) greater diethylhexyl phthalate.

DISCUSSION

We found that reported SCP use was associated with urinary phthalate/replacement metabolites in young children. These results may inform policymakers, clinicians, and parents to help limit children's exposure to developmental toxicants. https://doi.org/10.1289/EHP13937.

Endocrine disrupting chemicals in children's and their parents' urine: Is the exposure related to the Chinese and Western lifestyle?

Children are known to be more vulnerable to exposure to endocrine-disrupting chemicals (EDCs) compared to adults, but evaluating the exposure pathways can be challenging. This research employed target and non-target analysis (NTA) to examine the exposure characteristics of EDCs in spot urine samples collected from 46 children's (aged 3-12 years) and their parents in Hong Kong (Chinese/Western lifestyle) and Guangzhou (mainly Chinese lifestyle). The results revealed that the geometric mean concentrations of phthalate esters metabolites (mPAEs) and bisphenols (BPs) in children's urine were 127.3 μg/gcrea and 2.5 μg/gcrea in Guangzhou, and 93.7 μg/gcrea and 2.9 μg/gcrea in Hong Kong, respectively, which were consistent with global levels. NTA identified a total of 1069 compounds, including 106 EDCs, commonly detected in food, cosmetics, and drugs. Notable regional differences were observed between Guangzhou and Hong Kong with potential sources of EDCs including dietary and cosmetic additives, toys, flooring and dust, as well as differences in lifestyles, diet, and living environment. However, age was found to significantly impact EDC exposure. The quantified EDCs (mPAEs and BPs) posed possible health risks to 60% of the children. Moreover, the presence of caffeine in children's urine, which exhibited higher detection rates in children from Hong Kong (95.6%) and Guangzhou (44.4%), warrants further attention. The sources of EDCs exposure in these regions need to be fully confirmed.

Exposure of children to brominated flame retardants and heavy metals in Morocco: Urine and blood levels in association with global cytosine and adenine methylation

Persistent pollutants, namely brominated flame retardants (BFRs) and heavy metals, are compounds that are added to a wide range of products and materials for preventing ignition, increasing the functionality of materials or improving their performance, e.g. electric conductivity. The exposure of children might consequently be inferred, through indoor dust and hand-to-mouth or toy-chewing behaviors. The current study is aimed at assessing the exposure of Moroccan children to BFRs and heavy metal elements, and evaluating their associations with global DNA methylation. First, parents responded to a questionnaire pertaining to children's lifestyle, then blood and urine samples were collected from (n = 93) children aged between 5 and 11 years for biomonitoring and DNA methylation analysis. BFRs were detected in 54.84% of samples with a median concentration of 0.01 nmol/mL (range: 0.004-0.051 nmol/mL) while metal elements were detected in more than 90% of samples. BFRs showed no variations with global DNA methylation, unlike metal elements, which revealed significant associations with global DNA methylation markers, namely 5-mC, 5-hmC and N⁶-mA levels. Moroccan children may be exposed to flame retardants and heavy metals through several routes. Further research is required to assess the exposure and the health impacts of environmental pollutants and ultimately protect the Moroccan population by the prevention of adverse health effects.

Characteristics and health risks of population exposure to phthalates via the use of face towels

The production of face towels is growing at an annual rate of about 4% in China, reaching 1.13 million tons by 2021. Phthalates (PAEs) are widely used in textiles, and face towels, as an important household textile, may expose people to PAEs via the skin, further leading to health risks. We collected new face towels and analyzed the distribution characterization of PAEs in them. The changes of PAEs were explored in a face towel use experiment and a simulated laundry experiment. Based on the use of face towels by 24 volunteers, we calculated the estimated daily intake (EDI) and comprehensively assessed the hazard quotient (HQ), hazard index (HI), and dermal cancer risk (DCR) of PAEs exposure in the population. PAEs were present in new face towels at total concentrations of <MDL-2388 ng/g, with a median of 173.2 ng/g, which was a lower contamination level compared with other textiles. PAE contents in used face towels were significantly higher than in new face towels. The concentrations of PAEs in coral velvet were significantly higher than those in cotton. Water washing removed some PAEs, while detergent washing increased the PAE content on face towels. Gender, weight, use time, and material were the main factors affecting EDI. The HQ and HI were less than 1, which proved PAEs had no significant non-carcinogenic health risks. Among the five target PAEs studied, DEHP was the only carcinogenic PAE and may cause potential health risks after long-term exposure. Therefore, we should pay more attention to DEHP.

Associations of urinary phthalate metabolites with household environments among mothers and their preschool-age children

Phthalates have become a matter of public health concern due to their extensive use worldwide and negative health effects. The evaluation of potential sources of phthalate exposure is crucial to design prevention strategies, especially for vulnerable populations. This study included 528 mother-child pairs in the Taiwan Mother Infant Cohort Study who were followed up at ages 3-6 years between 2016 and 2020. Each mother was interviewed by using a structured questionnaire containing questions on demographic characteristics and household environment factors, such as the use of plastic food packaging, residential visible mold, insecticide sprays, and electric mosquito repellents. Eleven phthalate metabolites were analyzed in urine samples simultaneously collected from the mother-child pairs. The phthalate metabolite urinary concentrations were higher among the children than among their mothers, except those of mono-ethyl phthalate (MEP) and mono-2-ethylhexyl phthalate (MEHP). Multiple linear regression analyses showed that urine samples collected during the summer showed higher concentrations of phthalate metabolites than those collected during the winter. Family income levels had negative associations with the concentrations of MnBP and metabolites of di-2-ethylhexyl phthalate (DEHP) in children. The use of plastic food packaging was positively associated with mono-n-butyl phthalate (MnBP) and metabolites of DEHP in mothers. Residential visible mold or mold stains were significantly associated with higher MnBP and DEHP metabolite concentrations in children. The use of insecticide sprays was positively associated with MnBP concentrations in children. Significant associations between household environmental factors and phthalate exposure were mostly found in children, potentially indicating different exposure pathways between mothers and their children. Findings from this study provide additional information for the design of prevention strategies to protect the health of children and women.

MiR-93 alleviates DEHP plasticizer-induced neurotoxicity by negatively regulating TNFAIP1 and inhibiting ubiquitin-mediated degradation of CK2β

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer that is widely used in various products, such as plastic packaging in food industries. As an environmental endocrine disruptor, it induces adverse effects on brain development and function. However, the molecular mechanisms by which DEHP induces learning and memory impairment remain poorly understood. Herein, we found that DEHP impaired learning and memory in pubertal C57BL/6 mice, decreased the number of neurons, downregulated miR-93 and the β subunit of casein kinase 2 (CK2β), upregulated tumor necrosis factor-induced protein 1 (TNFAIP1), and inhibited Akt/CREB pathway in mouse hippocampi. Coimmunoprecipitation and western blotting assays revealed that TNFAIP1 interacted with CK2β and promoted its degradation by ubiquitination. Bioinformatics analysis showed a miR-93 binding site in the 3'-untranslated region of Tnfaip1. A dual-luciferase reporter assay revealed that miR-93 targeted TNFAIP1 and negatively regulated its expression. MiR-93 overexpression prevented DEHP-induced neurotoxicity by downregulating TNFAIP1 and then activating CK2/Akt/CREB pathway. These data indicate that DEHP upregulates TNFAIP1 expression by downregulating miR-93, thus promoting ubiquitin-mediated degradation of CK2β, subsequently inhibiting Akt/CREB pathway, and finally inducing learning and memory impairment. Therefore, miR-93 can relieve DEHP-induced neurotoxicity and may be used as a potential molecular target for prevention and treatment of related neurological disorders.

A multi-framework for bisphenols based on their high performance and environmental friendliness: Design, screening, and recommendations

Bisphenols (BPs) have gained significant attention due to their extensive use in the production of medical equipment, packaging materials, and everyday commodities. Urgent attention is required for assessing and identifying the risks associated with BP exposure to the environment and human health, as well as developing regulatory strategies. In this paper, 29 common BPs were selected as the research object, high-performance BP substitutes with environmental and human health friendliness characteristics were designed and screened. The above eight BP substitutes were considered as examples, and the first-level evaluation indicators of BPs and their substitutes were predicted using a random forest classification/regression model. Subsequently, the key indicators affecting the first-level evaluation indicators were ranked. The ranking results were environmental friendliness (64.30%) > human health risk (18.00%) > functionality (17.69%), indicating that environmental friendliness was the main influencing factor for the first-level evaluation indicators of BPs and their substitutes. Therefore, the study employed density functional theory (DFT) to simulate the biodegradation pathways of BPs and their substitutes in contaminated soil and landfill leachate, using Derivative-50 as an example. Furthermore, the environmental risk associated with the degradation products was evaluated, and regulatory recommendations based on risk identification were proposed.

Exposure to Phthalates in European Children, Adolescents and Adults since 2005: A Harmonized Approach Based on Existing HBM Data in the HBM4EU Initiative

Phthalates are mainly used as plasticizers and are associated inter alia with adverse effects on reproductive functions. While more and more national programs in Europe have started monitoring internal exposure to phthalates and its substitute 1,2-Cyclohexanedicarboxylic acid (DINCH), the comparability of results from such existing human biomonitoring (HBM) studies across Europe is challenging. They differ widely in time periods, study samples, degree of geographical coverage, design, analytical methodology, biomarker selection, and analytical quality assurance level. The HBM4EU initiative has gathered existing HBM data of 29 studies from participating countries, covering all European regions and Israel. The data were prepared and aggregated by a harmonized procedure with the aim to describe-as comparably as possible-the EU-wide general population's internal exposure to phthalates from the years 2005 to 2019. Most data were available from Northern (up to 6 studies and up to 13 time points), Western (11; 19), and Eastern Europe (9; 12), e.g., allowing for the investigation of time patterns. While the bandwidth of exposure was generally similar, we still observed regional differences for Butyl benzyl phthalate (BBzP), Di(2-ethylhexyl) phthalate (DEHP), Di-isononyl phthalate (DiNP), and Di-isobutyl phthalate (DiBP) with pronounced decreases over time in Northern and Western Europe, and to a lesser degree in Eastern Europe. Differences between age groups were visible for Di-n-butyl phthalate (DnBP), where children (3 to 5-year olds and 6 to 11-year olds) had lower urinary concentrations than adolescents (12 to 19-year-olds), who in turn had lower urinary concentrations than adults (20 to 39-year-olds). This study is a step towards making internal exposures to phthalates comparable across countries, although standardized data were not available, targeting European data sets harmonized with respect to data formatting and calculation of aggregated data (such as developed within HBM4EU), and highlights further suggestions for improved harmonization in future studies.

The potential mechanisms of TBBPA bis(2-hydroxyethyl) ether induced developmental neurotoxicity in juvenile zebrafish (Danio rerio)

TBBPA bis(2-hydroxyethyl) ether (TBBPA-DHEE), one of the main derivatives of TBBPA, has been widely detected in environmental samples and been discovered to be potential neurotoxic. In this study, the juvenile zebrafish were selected as the research subject to explore the neurotoxicity and its mechanism of low-dose TBBPA-DHEE exposure, and to reveal the neurotoxicity susceptibility in different sexes. Behavioral studies revealed that TBBPA-DHEE could significantly reduce the swimming velocity, maximum acceleration and cumulative duration of high-speed mobility, significantly increasing the cumulative duration of low-speed mobility and average social distance. It significantly reduced the contents of ATP, glutamate and Ca²⁺ in the whole brain. The histopathological study demonstrated that TBBPA-DHEE could cause brain tissue damage in female and male juvenile zebrafish. The comprehensive data analysis indicated that female zebrafish were more susceptible to TBBPA-DHEE exposure than male zebrafish. Transcriptomic analysis showed that TBBPA-DHEE could significantly affect the expressions of behavioral and development-related genes. Furthermore, female and male juvenile zebrafish have different molecular mechanisms of neurotoxicity. For female juvenile zebrafish, the potential mechanism of neurotoxicity could be that it interfered with the feedback regulation of nerves by affecting the related genes expressions in the signaling pathways such as Ca²⁺ signaling, Wnt signaling and synapses. For male juvenile zebrafish, the potential mechanism of neurotoxicity may be through affecting the expression of related genes in hormones and neuro-related genes. This research could reveal the potential neurotoxicity of TBBPA-DHEE to aquatic organisms, which will be helpful to reveal the health effects of the emerging environmental pollutants.

Exposure to flame retardants in European children - Results from the HBM4EU aligned studies

Many legacy and emerging flame retardants (FRs) have adverse human and environmental health effects. This study reports legacy and emerging FRs in children from nine European countries from the HBM4EU aligned studies. Studies from Belgium, Czech Republic, Germany, Denmark, France, Greece, Slovenia, Slovakia, and Norway conducted between 2014 and 2021 provided data on FRs in blood and urine from 2136 children. All samples were collected and analyzed in alignment with the HBM4EU protocols. Ten halogenated FRs were quantified in blood, and four organophosphate flame retardants (OPFR) metabolites quantified in urine. Hexabromocyclododecane (HBCDD) and decabromodiphenyl ethane (DBDPE) were infrequently detected (<16% of samples). BDE-47 was quantified in blood from Greece, France, and Norway, with France (0.36 ng/g lipid) having the highest concentrations. BDE-153 and -209 were detected in <40% of samples. Dechlorane Plus (DP) was quantified in blood from four countries, with notably high median concentrations of 16 ng/g lipid in Slovenian children. OPFR metabolites had a higher detection frequency than other halogenated FRs. Diphenyl phosphate (DPHP) was quantified in 99% of samples across 8 countries at levels ∼5 times higher than other OPFR metabolites (highest median in Slovenia of 2.43 ng/g lipid). FR concentrations were associated with lifestyle factors such as cleaning frequency, employment status of the father of the household, and renovation status of the house, among others. The concentrations of BDE-47 in children from this study were similar to or lower than FRs found in adult matrices in previous studies, suggesting lower recent exposure and effectiveness of PBDE restrictions.

Lysmeral Exposure in Children and Adolescences Participating in the German Environmental Survey (2012-2015): Integrating Sex/Gender into Analysis

Comprehensive consideration of the biological and social diversities of sex and gender as well as their interdependencies is mostly missing in human biomonitoring (HBM) studies. Using the INGER sex/gender concept as theoretical background, we analyzed differences in exposure to lysmeral, a compound commonly found as a fragrance in cosmetics, personal care, and household products, in 2294 children and adolescents in Germany using decision tree, regression, and mediation analysis. The variables "sex assigned at birth" and "age", as well as well as use of personal care products and fabric conditioner proved to have the highest explanatory value. Mediating effects of behaviour associated with societal gender expectations were observed, as the use of cosmetics correlated highly with lysmeral metabolites concentrations in girls between 6 and 17 years, with the strongest effect in adolescents between 14 and 17 years old. In the youngest age group (3-5 years) boys showed higher concentration of the metabolite tert-butylbenzoic acid (TBBA) compared to girls of the same age but only if TBBA urine concentrations were normalized on creatinine. Our study offers the first retrospective sex/gender assessment of HBM data. It demonstrates the possibilities to rethink and broaden sex/gender analysis in existing HBM-studies and highlights the need for inclusion of new sex/gender concepts in the design of new studies.

Exposure to Endocrine Disruptors (Di(2-Ethylhexyl)phthalate (DEHP) and Bisphenol A (BPA)) in Women from Different Residing Areas in Italy: Data from the LIFE PERSUADED Project

Phthalates and bisphenol A (BPA) are plasticizers used in many industrial products that can act as endocrine disruptors and lead to metabolic diseases. During the LIFE PERSUADED project, we measured the urinary concentrations of BPA and Di(2-ethylhexyl)phthalate (DEHP) metabolites in 900 Italian women representative of the Italian female adult population (living in the north, centre, and south of Italy in both rural and urban areas). The whole cohort was exposed to DEHP and BPA with measurable levels above limit of detection in more than 99% and 95% of the samples, respectively. The exposure patterns differed for the two chemicals in the three macro-areas with the highest urinary levels for DEHP in south compared to central and northern Italy and for BPA in northern compared to central and southern Italy. BPA levels were higher in women living in urban areas, whereas no difference between areas was observed for DEHP. The estimated daily intake of BPA was 0.11 μg/kg per day, about 36-fold below the current temporary tolerable daily intake of 4 μg/kg per day established by the EFSA in 2015. The analysis of cumulative exposure showed a positive correlation between DEHP and BPA. Further, the reduction of exposure to DEHP and BPA, through specific legislative measures, is necessary to limit the harmfulness of these substances.

Early life exposure to triclosan from antimicrobial daily necessities may increase the potential risk of autism spectrum disorder: A multicenter study in China

BACKGROUND

Autism spectrum disorders (ASD) are a group of complex neurodevelopmental disorders with unclear etiologies. Our recent work indicated that maternal exposure to triclosan (TCS) significantly increased the autistic-like behavior in rats, possibly through disrupting neuronal retinoic acid signaling. Although environmental endocrine disruptors (EEDs) have been associated with autism in humans, the relationship between TCS, one of the EEDs found in antibacterial daily necessities, and autism has received little attention.

OBJECTIVE

The aims of this multicenter study were to evaluate TCS concentrations in typically developing (TD) children and ASD children, and to determine the relationship between TCS levels and the core symptoms of ASD children.

METHODS

A total of 1345 children with ASD and 1183 TD children were enrolled from 13 cities in China. Ages ranged between 2 and 7 years. A questionnaire was used to investigate the maternal use of antibacterial daily necessities (UADN) during pregnancy. The core symptoms of ASD were evaluated using the Autism Behavior Checklist (ABC), Childhood Autism Rating Scale (CARS), Social Response Scale (SRS), and the Children Neuropsychological and Behavior Scale-Revision 2016 (CNBS-R2016). The TCS concentration was measured using LC-MS/MS.

RESULTS

Maternal UADN during pregnancy may be an unrecognized potential environmental risk factor for ASD (OR=1.267, P = 0.023). Maternal UADN during pregnancy strongly correlated with TCS levels in the offspring (Adjusted β = 0.277, P < 0.001). TCS concentration was higher in ASD children (P = 0.005), and positively correlated with ABC (Sensory subscales: P = 0.03; Social self-help subscales: P = 0.011) and SRS scale scores (Social awareness subscales: P = 0.045; Social communication subscales: P = 0.001; Autism behavior mannerisms subscales: P = 0.006; SRS total score: P = 0.003) in ASD children. This association was more pronounced in boys than in girls.

CONCLUSION

To our knowledge, this is the first case-control study to examine the correlation between TCS and ASD. Our results suggest that maternal UADN during pregnancy may be a potential risk of ASD in offspring. Further detection of TCS levels showed that maternal UADN during pregnancy may be associated with excessive TCS exposure. In addition, the level of TCS in children with ASD is higher than TD children. The higher levels of TCS in children with ASD may be significantly associated with more pronounced core symptoms, and this association was more significant in male children with ASD.

Assessment of health risk and dose-effect of DNA oxidative damage for the thirty chemicals mixture of parabens, triclosan, benzophenones, and phthalate esters

Humans are constantly exposed to parabens (PBs), triclosan (TCS), benzophenones (BPs), and phthalate esters (PAEs) due to the widespread existence of these chemicals in personal care products (PCPs), and the high frequency of usage for humans. Previous studies indicated each class of the above-mentioned chemicals can exhibit potential adverse effects on humans, in particular DNA oxidative damage. However, the health risk assessment of combined exposures to multiple PCPs is limited, especially the overall dose-effect of mixtures of these chemicals on DNA oxidative damage. In this study, we measured the urinary levels of 6 PBs, TCS, 8 BPs, 15 metabolites of PAEs (mono-PAEs), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) from 299 adults simultaneously. PBs, TCS, BPs, and mono-PAEs were frequently detected in urinary samples with median concentrations of 52.888, 0.737, 1.305, and 141.381 ng/ml, suggesting a broad, low-level exposure among participants. Risk assessments indicated approximately 22% and 15% of participants suffered health risks (Hazard index >1) from exposure to TCS and PAEs. The relationship between 8-OHdG levels and chemical exposure was estimated by Bayesian kernel machine regression (BKMR) models. It indicated an overall positive correlation between the mixture of these chemicals and 8-OHdG, with methylparaben and mono-benzyl phthalate contributing the most to this association. Of note, sex-related differences were observed, in which exposure to PCPs led to higher health risks and more pronounced dose-effect on DNA damage in the female population. Our novel findings reveal the health risks of exposure to low-level PCPs mixtures and further point out the overall dose-response relationship between DNA oxidative damage and PCP mixtures.

Personal care product use and lifestyle affect phthalate and DINCH metabolite levels in teenagers and young adults

Humans are widely exposed to phthalates and their novel substitutes, and considering the negative health effects associated with some phthalates, it is crucial to understand population levels and exposure determinants. This study is focused on 300 urine samples from teenagers (aged 12-17) and 300 from young adults (aged 18-37) living in Czechia collected in 2019 and 2020 to assess 17 plasticizer metabolites as biomarkers of exposure. We identified widespread phthalate exposure in the study population. The diethyl phthalate metabolite monoethyl phthalate (MEP) and three di (2-ethylhexyl) phthalate metabolites were detected in the urine of >99% of study participants. The highest median concentrations were found for metabolites of low-molecular-weight (LMW) phthalates: mono-n-butyl phthalate (MnBP), monoisobutyl phthalate (MiBP) and MEP (60.7; 52.6 and 17.6 μg/L in young adults). 1,2-cyclohexanedicarboxylic acid diisononyl ester (DINCH) metabolites were present in 68.2% of the samples with a median of 1.24 μg/L for both cohorts. Concentrations of MnBP and MiBP were similar to other European populations, but 5-6 times higher than in populations in North America. We also observed large variability in phthalate exposures within the study population, with 2-3 orders of magnitude differences in urinary metabolites between high and low exposed individuals. The concentrations varied with season, gender, age, and lifestyle factors. A relationship was found between high levels of MEP and high overall use of personal care products (PCPs). Cluster analysis suggested that phthalate exposures depend on season and multiple lifestyle factors, like time spent indoors and use of PCPs, which combine to lead to the observed widespread presence of phthalate metabolites in both study populations. Participants who spent more time indoors, particularly noticeably during colder months, had higher levels of high-molecular weight phthalate metabolites, whereas participants with higher PCP use, particularly women, tended to have higher concentration of LMW phthalate metabolites.

Exposure to phthalates from personal care products: Urinary levels and predictors of exposure

Phthalates are a large group of chemicals used in many everyday consumer products such as food packaging, household cleaners, cosmetics, fragrances and personal care products (PCPs). A number of diseases such as obesity, hypertension, as well as reproductive system effects and endocrine disorders have been linked to phthalate exposure through the use of PCPs, due to their frequent use and high phthalate content. In this study we review available literature on phthalates and their metabolites in urine and report the various determinants of exposure through the use of PCPs in infants, toddlers, children and adults. The range of creatinine-adjusted concentrations for each phthalate was 1.5-14956.1 μg/g for MEP, 0.4-94.5 μg/g for MEHP, 0.39-425.9 μg/g for MEHHP, 0.5-481.3 μg/g for MEOHP, 0.1-755.1 μg/g for MBzP, and 0.3-401.4 μg/g for MiBP. Time of sampling, frequency of use, race and age are critical factors that influence phthalate concentrations. Using PCPs 48 h before urine collection, using a combination of PCPs (i.e., particularly leave-on versus rinse-off products), being younger (i.e., children compared to their mothers), and being a woman of colour (i.e., Mexican-American and black versus white) leads to higher phthalate levels in urine. The most striking association between any phthalate and PCPs was observed between MEP and perfumes or fragrance-containing products such as shampoos, body lotions and hair products. Future studies should focus on different types and brands of PCPs (i.e., branded versus generic), explore possible ethnic/racial differences and the applicability of non-invasive matrices such as nails and hair for phthalate biomonitoring, as well as intervention studies that explore behavioural changes.

Comprehensive LC-MS/MS method combined with tandem hybrid hydrolysis for multiple exposure assessment of multiclass environmental pollutants

Environmental pollutants (EPOLs), such as phthalates, volatile organic compounds, phenols, parabens, polycyclic aromatic hydrocarbons, pyrethroids, and environmental tobacco smoke, are highly heterogeneous compounds. Recently, attention has been drawn to the assessment of the combinatory effects of multiple EPs. To correlate multiple exposures with potential health implications, advanced comprehensive analytical methods covering multiclass EPOLs are essential. However, because of several technical problems associated with enzyme hydrolysis, simultaneous extraction, and multiresidue liquid chromatography-tandem mass spectrometry analysis, it is difficult to establish a comprehensive method covering a number of EPOLs in a single sample preparation and analytical run. We developed tandem hybrid hydrolysis, modified direct injection, and a comprehensive mobile phase to overcome these technical problems and established a comprehensive analytical method for simultaneous biomonitoring of multiclass EPOLs. Tandem hybrid hydrolysis using β-glucuronidase and consecutive acid hydrolysis allowed selective hydrolysis of glucuronide- and sulfate-conjugated metabolites without phthalate degradation. The comprehensive mobile phase composed of 0.01% acetic acid and acetonitrile enabled us to simultaneously analyze 86 EPOLs, with good chromatographic behavior and ionization efficiency. Modified direct injection allowed a small amount of sample and simultaneous urinary extraction. The method was validated and applied to 39 urine samples from 19 mother-newborn pairs for multiple exposure assessment. Results showed that BP-3, a general component in sunblock products, and monoethyl phthalate, a metabolite of diethyl phthalate, exhibit a clear positive correlation between mothers and newborns. Therefore, the developed method has potential as a novel analytical tool for long-term, large-scale, and data-rich human biomonitoring of EPOLs.

Nonylphenol exposure in 7-year-old Japanese children between 2012 and 2017- Estimation of daily intakes based on novel urinary metabolites

Nonylphenol (NP) has been under scrutiny for decades due to its endocrine-disrupting properties and its ubiquity in the environment. Despite its widespread occurrence, robust and reliable exposure data are rare. In this study, we used human biomonitoring (HBM) measuring the novel urinary alkyl-chain-oxidized biomarkers OH-NP and oxo-NP to determine NP exposure in 7-year-old Japanese children. The new biomarkers are advantageous over measuring unchanged NP because they are not prone to external contamination. We analyzed 180 first morning void urine samples collected between 2012 and 2017. OH-NP and oxo-NP were detected in 100% and 66% of samples at median concentrations of 2.69 and 0.36 µg/L, respectively. 10-fold concentration differences between OH-NP and oxo-NP are in line with recent findings on human NP metabolism. Based on OH-NP we back-calculated median and maximum NP daily intakes (DI) of 0.14 and 0.95 µg/(kg bw*d). These DIs are rather close to but still below the current provisional tolerable daily intake of 5 µg/(kg bw*d) by the Danish Environmental Protection Agency. Between 2012 and 2017 the DIs decreased by an average of 4.7% per year. We observed no seasonal changes or gender differences and questionnaire data on food consumption, housing characteristics or pesticide use showed no clear associations with NP exposure. Urinary OH-NP was weakly associated with the oxidative stress (lipid peroxidation) biomarkers N-ε-hexanoyl-lysine (HEL) and trans-4-hydroxy-2-nonenal (HNE) (Spearman ρ = 0.30 and 0.22, respectively), but not with 8-hydroxy-2'-deoxyguanosine (8-OHdG). Further research is needed to identify and understand the major sources of NP exposure and to investigate a potential role in oxidative stress. This study is the first to investigate NP exposure in Japanese children based on robust and sensitive HBM data. It is a first step to fill the long-standing gap in quantitative human NP exposure monitoring and risk assessment.

Prenatal Bisphenol A Exposure and Early Childhood Behavior and Cognitive Function: A Chinese Birth Cohort Study

INTRODUCTION

Biomonitoring of bisphenol A (BPA) in human blood is still scarce, although already noticeable. We aimed to examine the associations between prenatal serum BPA concentrations and behavior and cognitive function in preschool children.

METHODS

A total of 1,782 mother-child pairs with complete demographic information, blood samples, and psychological measurements were included from the China-Anhui Birth Cohort (C-ABCS). We detected serum BPA concentrations and assessed children's neurodevelopment using a set of psychometric scales.

RESULTS

The median prenatal maternal serum BPA concentration was 0.23 (P25, P75: 0.07, 0.52) ng/mL, with a detection frequency of 85.19%. Compared with the girls with the lowest concentrations, those with highest BPA concentrations had increased risks of inhibitory self-control impairment [relative risk (RR) = 3.66, 95% confidence interval (CI): 1.53, 7.58], emergent metacognition impairment (RR = 1.70, 95% CI: 1.07, 2.78), conduct problem (RR = 1.68, 95% CI: 1.12, 2.39), peer relationship problem (RR = 2.57, 95% CI: 1.33, 4.47), higher total difficulties score (RR = 1.76, 95% CI: 1.12, 2.67), and higher impact factor score (RR = 1.52, 95% CI: 1.11, 2.05), while the boys with the highest prenatal BPA concentrations had an increased risk of conduct problem compared with those with the lowest concentrations (RR = 1.59, 95% CI: 1.09, 2.24) (P-interaction = 0.011). After stratification by age, high prenatal BPA concentrations were associated with increased ADHD (RR = 4.44, 95% CI: 1.54, 10.85) among children aged 3 years, not among children aged 4 years.

CONCLUSION

Our study revealed the sex-specific and age-specific impacts of prenatal BPA exposure on preschool children's cognitive and behavioral development.

Urinary Concentrations of Major Phthalate and Alternative Plasticizer Metabolites in Children of Thailand, Indonesia, and Saudi Arabia, and Associated Risks

Phthalates are widely used in consumer products and are well-known for adverse endocrine outcomes. Di-(2-ethylhexyl) phthalate (DEHP), one of the most extensively used phthalates, has been rapidly substituted with alternative plasticizers in many consumer products. The aim of this study was to assess urinary phthalate and alternative plasticizer exposure and associated risks in children of three Asian countries with different geographical, climate, and cultural characteristics. Children were recruited from elementary schools of Saudi Arabia (n = 109), Thailand (n = 104), and Indonesia (n = 89) in 2017-2018, and their urine samples were collected. Metabolites of major phthalates and alternative plasticizers were measured in the urine samples by HPLC-MS/MS. Urinary metabolite levels differed substantially between the three countries. Metabolite levels of diisononyl phthalate (DiNP), diisodecyl phthalate (DiDP), di(2-ethylhexyl) terephthalate (DEHTP), and 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) were the highest in Saudi children: Median urinary concentrations of oxo-MiNP, OH-MiDP, 5cx-MEPTP, and OH-MINCH were 8.3, 8.4, 128.0, and 2.9 ng/mL, respectively. Urinary DEHP metabolite concentrations were the highest in the Indonesian children. The hazard index (HI) derived for the plasticizers with antiandrogenicity based reference doses (RfD_AA) was >1 in 86%, 80%, and 49% of the Saudi, Indonesian, and Thai children, respectively. DEHP was identified as a common major risk driver for the children of all three countries, followed by DnBP and DiBP depending on the country. Among alternative plasticizers, urinary DEHTP metabolites were detected at levels comparable to those of DEHP metabolites or higher among the Saudi children, and about 4% of the Saudi children exceeded the health based human biomonitoring (HBM)-I value. Priority plasticizers that were identified among the children of three countries warrant refined exposure assessment for source identification and relevant exposure reduction measures.

Urinary triclosan in south China adults and implications for human exposure

Triclosan (TCS) is widely applied in personal care products (PCPs) as an antimicrobial preservative. Due to its toxicity and potential risk to human health, TCS has attracted mounting concerns in recent years. However, biomonitoring of TCS in large human populations remains limited in China. In this study, 1163 adults in South China were recruited and urinary TCS concentrations were determined. TCS was detected in 99.5% of urine samples, indicating broad exposure in the study population. Urinary concentrations of TCS ranged from below the limit of detection (LOD) to 270 μg/L, with a median value of 3.67 μg/L. Urinary TCS concentrations from individuals were all lower than the Biomonitoring Equivalents reference dose, suggesting relatively low health risk in the participants. TCS concentrations did not differ significantly between sexes or education levels (p > 0.05). Nevertheless, marital status and age were found to be positively influence TCS levels (p < 0.001). After adjustment for body mass index (BMI), age was determined to be positively associated with TCS concentrations (p < 0.05), particularly in the age group from 31 to 51 years old. This study provides a baseline of urinary TCS exposure in South China general adult populations.

Human-Biomonitoring derived exposure and Daily Intakes of Bisphenol A and their associations with neurodevelopmental outcomes among children of the Polish Mother and Child Cohort Study

BACKGROUND

Bisphenol A (BPA) is an industrial chemical mostly used in the manufacture of plastics, resins and thermal paper. Several studies have reported adverse health effects with BPA exposures, namely metabolic disorders and altered neurodevelopment in children, among others. The aim of this study was to explore BPA exposure, its socio-demographic and life-style related determinants, and its association with neurodevelopmental outcomes in early school age children from Poland.

METHODS

A total of 250 urine samples of 7 year-old children from the Polish Mother and Child Cohort Study (REPRO_PL) were analyzed for BPA concentrations using high performance liquid chromatography with online sample clean-up coupled to tandem mass spectrometry (online-SPE-LC-MS/MS). Socio-demographic and lifestyle-related data was collected by questionnaires or additional biomarker measurements. Emotional and behavioral symptoms in children were assessed using mother-reported Strengths and Difficulties Questionnaire (SDQ). Cognitive and psychomotor development was evaluated by Polish adaptation of the Intelligence and Development Scales (IDS) performed by trained psychologists.

RESULTS

Urinary BPA concentrations and back-calculated daily intakes (medians of 1.8 μg/l and 46.3 ng/kg bw/day, respectively) were similar to other European studies. Urinary cotinine levels and body mass index, together with maternal educational level and socio-economic status, were the main determinants of BPA levels in Polish children. After adjusting for confounding factors, BPA has been found to be positively associated with emotional symptoms (β: 0.14, 95% CI: 0.022; 0.27). Cognitive and psychomotor development were not found to be related to BPA levels.

CONCLUSIONS

This study represents the first report of BPA levels and their determinants in school age children in Poland. The exposure level was found to be related to child emotional condition, which can have long-term consequences including social functioning and scholastic achievements. Further monitoring of this population in terms of overall chemical exposure is required.

Human biomonitoring of bisphenol A along pregnancy: An exposure reconstruction of the EXHES-Spain cohort

This study was aimed at reconstructing the exposure to bisphenol (BPA) of 60 pregnant women from the EXHES-Spain cohort. A biomonitoring study was conducted by determining BPA levels in urine samples over the three trimesters of pregnancy. Moreover, the correlations between BPA levels and the role of different potential exposure sources, with special emphasis on the dietary intake, were also studied. Urine samples were subjected to dispersive liquid-liquid microextraction and the subsequent analysis via gas chromatography-mass spectrometry. BPA was detected in 76% of the urine samples. A significant decrease of urinary BPA levels was observed along pregnancy, as mean concentrations of creatinine-adjusted BPA were 4.64, 4.84 and 2.51 μg/g in the first, second and third trimester, respectively. This decrease was essentially associated with changes in the dietary habits of the pregnant women, including a lower intake of canned food and drinks. However, the potential role of other pregnancy-related biochemical or physiological factors should not be disregarded. Very interestingly, significant differences in urine BPA levels were found according to the fruit consumption pattern, as women who ate more citrus fruits showed lower BPA concentrations in urine. The reconstructed exposure to BPA was estimated in 0.072, 0.069 and 0.038 μg BPA/kg of body weight/day in the first, second and third trimesters, respectively. These values are far below the temporary tolerable daily intake (t-TDI) established by the EFSA.

A Review of Recent Studies on Bisphenol A and Phthalate Exposures and Child Neurodevelopment

Purpose of Review: Bisphenol A and phthalate have been found in the environment, as well as in humans. In this narrative review pre- and postnatal bisphenol A and phthalate exposures, their relationship to neurodevelopment, and the behavioral outcomes of children are elucidated, focusing in particular on the recent case-control, cross-sectional, and longitudinal studies. This review also introduces some of the possible mechanisms behind the observed associations between exposures and outcomes. Recent Findings: Although bisphenol A and phthalate exposure have been reported to influence neurobehavioral development in children, there are various kinds of test batteries for child neurodevelopmental assessment at different ages whose findings have been inconsistent among studies. In addition, the timing and number of exposure assessments have varied. Summary: Overall, this review suggests that prenatal exposure to bisphenol A and phthalates may contribute to neurobehavioral outcomes in children. The evidence is still limited; however, Attention Deficit Hyperactivity Disorder (ADHD) symptoms, especially among boys, constantly suggested association with both prenatal and concurrent exposure to bisphenol A. Although there is limited evidence on the adverse effects of prenatal and postnatal bisphenol A and phthalate exposures provided, pregnant women and young children should be protected from exposure based on a precautionary approach.

Di-(2-ethylhexyl) phthalate-induced hepatotoxicity exacerbated type 2 diabetes mellitus (T2DM) in female pubertal T2DM mice

Di-(2-ethylhexyl) phthalate (DEHP), one of the most common plasticizers, is closely associated with a high prevalence of pubertal type 2 diabetes mellitus (T2DM). Numerous studies have indicated that DEHP-induced metabolic toxicity exhibits sex differences. In this study, the sex differences in the effect of DEHP on pubertal T2DM (P-T2DM) mice, the susceptibility of female P-T2DM mice to DEHP-induced metabolic toxicity, and the underlying mechanisms were investigated. DEHP exposure exacerbated metabolic disorders in female P-T2DM mice. Factorial analysis showed that female P-T2DM mice were more sensitive to DEHP exposure than female normal mice and male P-T2DM mice. It was determined by integrated biomarker response results that female P-T2DM mice had higher risks of developing T2DM, metabolic disorders, cardiovascular events and hepatotoxicity than male P-T2DM mice. Moreover, hepatic transcriptome analysis emphasized the effects of DEHP on the expression of oxidative injury- and metabolic function-related genes. Western blotting indicated that DEHP activated Jun-N-terminal kinase (JNK) and impaired insulin sensitivity in the liver, which were the main causes of DEHP-exacerbated metabolic abnormalities in P-T2DM mice. Our study revealed that compared with normal mice and male P-T2DM mice, female P-T2DM mice tend to suffer from increased DEHP-induced metabolic toxicity, which was primarily attributed to hepatotoxicity.

A two-step gas chromatography-tandem mass spectrometry method for measurement of multiple environmental pollutants in human plasma

Individuals are exposed to a wide variety of chemicals over their lifetime, yet current understanding of mixture toxicology is still limited. We present a two-step analytical method using a gas chromatograph-triple quadrupole mass spectrometer that requires less than 1 mL of sample. The method is applied to 183 plasma samples from a study population of children with autism spectrum disorder, their parents, and unrelated neurotypical children. We selected 156 environmental chemical compounds and ruled out chemicals with detection rates less than 20% of our study cohort (n = 61), as well as ones not amenable to the selected extraction and analytical methods (n = 34). The targeted method then focused on remaining chemicals (n = 61) plus 8 additional polychlorinated biphenyls (PCBs). Persistent pollutants, such as p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and PCB congeners 118 and 180, were detected at high frequencies and several previously unreported chemicals, including 2,4,6-trichlorophenol, isosafrole, and hexachlorobutadiene, were frequently detected in our study cohort. This work highlights the benefits of employing a multi-step analytical method in exposure studies and demonstrates the efficacy of such methods for reporting novel information on previously unstudied pollutant exposures.

Sentinels of synthetics - a comparison of phthalate exposure between common bottlenose dolphins (Tursiops truncatus) and human reference populations

Phthalates are chemical esters used as additives in common consumer goods, such as plastics, household cleaners, and personal care products. Phthalates are not chemically bound to the items to which they are added and can easily leach into the surrounding environment. Anthropogenic drivers, such as coastal plastic pollution and wastewater runoff, increase the exposure potential for coastal marine fauna. Phthalate exposure in free-ranging bottlenose dolphins has been the focus of recent study, with indications of heightened exposure to certain phthalate compounds. The objective of this study was to compare urinary phthalate metabolite concentrations among bottlenose dolphins (Tursiops truncatus) sampled in Sarasota Bay, FL, to levels reported in human samples collected as part of the Centers for Disease Control and Prevention's (CDC) National Health and Nutrition Examination Survey (NHANES). Monoethyl phthalate (MEP) and mono-(2-ethylhexyl) phthalate (MEHP) were the most prevalent metabolites detected in dolphin urine (n = 51; MEP = 29.41%; MEHP = 54.90%). The geometric mean (GM) concentration of MEP was significantly lower for dolphins (GM = 4.51 ng/mL; 95% CI: 2.77-7.34 ng/mL) compared to humans (p<0.05), while dolphin concentrations of MEHP (GM = 4.57 ng/mL; 95% CI: 2.37-8.80 ng/mL) were significantly higher than levels reported in NHANES (p<0.05). Health impacts to bottlenose dolphins resulting from elevated exposure to the MEHP parent compound (diethyl-2-ethylhexyl phthalate, DEHP) are currently unknown. However, given the evidence of endocrine disruption, reproductive impairment, and abnormal development in humans, pursuing investigations of potential health effects in exposed bottlenose dolphins would be warranted.

Background contamination of perfluoralkyl substances in a Belgian general population

The few Belgian studies on the human exposure to perfluoroalkyl substances (PFASs) have until now concerned the Northern part of Belgium (Flanders), while data related to Wallonia (South region) are missing. To fill this gap, 8 perfluorinated carboxylic acids and 3 perfluorinated alkyl sulfonates were measured in the serum of 242 adults (>18 years old) recruited in 2015 and living in the Province of Liege. Some multivariate regression models were also built with the PFAS levels and the participant's answers to a questionnaire about their diet and lifestyle habits in order to identify some predictors of exposure. The results obtained showed that although PFAS levels observed in our population seemed to be similar or lower than those reported in other countries, and especially lower than in the Northern part of Belgium, half of the population showed PFOS and PFOA serum levels above the health guidance values set by the German HBM Commission. As expected, age and gender were the main covariates explaining the different PFAS serum levels between participants, while breastfeeding (for women), consumption of fish and seafood, consumption of rice, and use of nail polish seemed also to impact the PFAS body burden of our population. Nevertheless, the statistical models were poorly predictive suggesting that the main sources of exposure were not taken into account.

Temporal trends and determinants of serum concentrations of per- and polyfluoroalkyl substances among Northern California mothers with a young child, 2009-2016

BACKGROUND/OBJECTIVE

Human exposure to per- and polyfluoroalkyl substances (PFAS) has changed since the early 2000s, in part, because of the phase-out and replacement of some long-chain PFAS. Studies of PFAS exposure and its temporal changes have been limited to date mostly to adults and pregnant women. We examined temporal trends and determinants of PFAS serum concentrations among mothers with a young child who participated in the CHARGE (CHildhood Autism Risk from Genetics and Environment) case-control study.

METHODS

We quantified nine PFAS in serum samples collected from 2009 to 2016 in 450 Northern California mothers when their child was 2-5 years old. With five compounds that were detected in more than 50% of the samples, we performed multiple regression to estimate least square geometric means (LSGMs) of PFAS concentrations with adjustment for sampling year and other characteristics that may affect maternal concentrations (e.g., breastfeeding duration). We also used time-related regression coefficients to calculate percent changes over the study period.

RESULTS

LSGM concentrations of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorohexane sulfonate (PFHxS) decreased over the study period [percent change (95% confidence interval): -10.7% (-12.7%, -8.7%); -10.8% (-12.9%, -8.5%); -8.0% (-10.5%, -5.5%), respectively]. On the other hand, perfluorononanoate (PFNA) and perfluorodecanoate (PFDA) showed mixed time trends. Among the selected covariates, longer breastfeeding duration was associated with decreased maternal serum concentrations of PFOA, PFOS, PFHxS, PFNA and PFDA.

CONCLUSIONS

Our study demonstrated that body burden of some common long-chain PFAS among California mothers with a young child decreased over the study period and that breastfeeding appears to contribute to the elimination of PFAS in lactating mothers.

Reconstruction of phthalate exposure and DINCH metabolites from biomonitoring data from the EXHES cohort of Tarragona, Spain: A case study on estimated vs reconstructed DEHP using the PBPK model

Phthalates are known endocrine disruptors (EDs) and are associated with potential diseases, such as obesity and diabetes. In 2002, the plasticizer 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) was introduced as an alternative to phthalates in the European market. The objective of this study was to evaluate the total exposure to phthalate and DINCH metabolites from EXHES Tarragona, Spain cohort of pregnant women. On the one hand, the analytical determination of phthalate and DINCH metabolites in urine was carried out. On the other hand, the reconstructed exposure was calculated for phthalates and DINCH using their metabolites concentration measured in the urine. Thirteen different phthalate metabolites and two metabolites of DINCH were measured and detected in almost all pregnant women's urine samples (n = 60). There were significant correlations between metabolites of the same parent compounds, and also between DEHP and MBzP metabolites, DiNP and BBZP metabolites, and DEHP and DiNP metabolites respectively. The exposure of pregnant women to phthalate and DINCH parent compounds were also back calculated using the levels of each metabolite found in pregnant women urine (reconstructed exposure). Besides, to demonstrate the utility of this approach, the physiologically based pharmacokinetic (PBPK) model was used to predict the cumulative amount of MEHP (a principal metabolite of DEHP in urine). To proceed with that, DEHP reconstructed exposure and estimated exposure from the same cohort (previously studied by the same authors) were simulated using the PBPK model. Results showed that the reconstructed-PBPK simulation was closer to the 24 h biomonitoring data than the estimated PBPK-simulation., This clearly shows that the combination of reconstructed exposure with the PBPK model is a good tool to predict chemicals exposure. However, some discrepancies between simulated and biomonitored values were found. This can be associated with other sources that contribute to the total exposure and emphasises the need to consider multi-routes exposure for the widely distributed chemicals like phthalates and DINCH.

Comparison of Transcriptomics Changes Induced by TCS and MTCS Exposure in Human Hepatoma HepG2 Cells

Triclosan (TCS) has been a widely used antibacterial agent in medical and personal care products in the last few decades. Methyl TCS (MTCS) is the major biotransformation product of TCS through replacement of the hydroxyl group with methoxy. Previous studies revealed that MTCS showed reduced toxicity but enhanced environmental persistence, when compared with TCS. Till date, the toxicological molecular mechanisms of TCS and MTCS remain to be clarified. This study aimed to investigate the transcriptomic changes in HepG2 cells induced by TCS and MTCS using microarray chips and to identify key target genes and related signal pathways. The microarray data showed that there were 1664 and 7144 differentially expressed genes (DEGs) in TCS- and MTCS-treated groups, respectively. Gene ontology (GO) enrichment and Kyoto Encyclopedia of genes and genomes (KEGG) analysis revealed that TCS and MTCS induced overlapping as well as distinct transcriptome signatures in HepG2 cells. Both TCS and MTCS could result in various biological responses in HepG2 cells mainly responding to biosynthetic and metabolic processes but probably through different regulatory pathways. Among the selected 50 GO terms, 9 GO terms belonging to the cellular component category were only enriched in the MTCS group, which are mainly participating in the regulation of cellular organelle's function. KEGG analysis showed that 19 and 59 pathway terms were separately enriched in TCS and MTCS groups, with only seven identical pathways. The selected 10 TCS-specific signal pathways are mainly involved in cell proliferation and apoptosis, while the selected 10 MTCS-specific pathways mainly take part in the regulation of protein synthesis and modification. The overall data suggested that MTCS induced more enriched DEGs, GO terms, and pathway terms than TCS. In conclusion, compared with TCS, MTCS presents lower polarity and stronger lipophilicity, enabling MTCS to cause more extensive transcriptomic changes in HepG2 cells, activate differentiated signal pathways, and finally lead to differences in biological responses.

Phthalates in preschool children's clothing manufactured in seven Asian countries: Occurrence, profiles and potential health risks

Phthalates could be introduced into clothing as chemical additives or impurities, becoming a potential source of human exposure. We measured the concentrations of 15 phthalates in new preschool children's clothing manufactured in seven Asian countries. Phthalates were prevalent in all samples, and total concentrations were 2.92-223 μg/g, indicating a moderate contamination level. Bis(2-ethylhexyl) phthalate, di(isobutyl) phthalate and di-n-butyl phthalate were the most abundant phthalates measured, representing a median of 48.5 %, 13.6 % and 13.4 % of the total concentrations, respectively. Total concentrations did not differ significantly by country of manufacture, while the concentrations of individual phthalates and their composition profiles varied widely. We also found differing phthalate levels by item type, fabric composition, and color. Under the assumed two exposure scenarios, the median of summed dermal exposure doses of six phthalate were 539 and 950 ng/kg of body weight per day, respectively. When children wore trousers, long-sleeved shirts, briefs and socks at the same time, the reproductive risks exceeded acceptable level, although the carcinogenic risk of DEHP was low. Our results suggested that new clothing is an important route of phthalate exposure to preschool children. More research is required to investigate the contaminations and associated with risks in child clothing.

In vitro estrogenic activity of binary and multicomponent mixtures with bisphenol A

Bisphenol A and its analogs are environmental contaminants with well known estrogenic and anti-androgenic activities. In studies of human biomonitoring, simultaneous exposure to multiple bisphenols was shown in different biological samples, at picomolar to low nanomolar concentrations. Evaluation of their combined toxicities will therefore be a more realistic and reliable predictor for estimation of health risks than evaluation of only the single chemicals. In the present study, estrogenic activities of individual bisphenols were evaluated, along with their binary and multicomponent mixtures including three- and four-component mixtures, using the Organisation for Economic Co-operation and Development validated transactivation assay with the hERα-Hela9903 cell line. Concentration-dependent estrogenic activity was confirmed for all of the tested bisphenols, in the nanomolar to micromolar range. Estrogenic activities of binary and multicomponent mixtures followed a concentration addition model. Although exposure to individual bisphenols remains below their effective doses, we demonstrate that as a mixture, they can contribute additively to toxicity. This study thus emphasizes the importance of mixture toxicity evaluation for risk assessment of compounds that act like the bisphenols.

Phthalate metabolites in urine of children and adolescents in Germany. Human biomonitoring results of the German Environmental Survey GerES V, 2014-2017

During the population representative German Environmental Survey of Children and Adolescents (GerES V, 2014-2017) 2256 first-morning void urine samples from 3 to 17 years old children and adolescents were analysed for 21 metabolites of 11 different phthalates (di-methyl phthalate (DMP), di-ethyl phthalate (DEP), butylbenzyl phthalate (BBzP), di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), di-cyclohexyl phthalate (DCHP), di-n-pentyl phthalate (DnPeP), di-(2-ethylhexyl) phthalate (DEHP), di-iso-nonyl phthalate (DiNP), di-iso-decyl phthalate (DiDP) and di-n-octyl phthalate (DnOP)). Metabolites of DMP, DEP, BBzP, DiBP, DnBP, DEHP, DiNP and DiDP were found in 97%-100% of the participants, DCHP and DnPeP in 6%, and DnOP in none of the urine samples. Geometric means (GM) were highest for metabolites of DiBP (MiBP: 26.1 μg/L), DEP (MEP: 25.8 μg/L), DnBP (MnBP: 20.9 μg/L), and DEHP (cx-MEPP: 11.9 μg/L). For all phthalates but DEP, GMs were consistently higher in the 3-5 years old children than in the 14-17 years old adolescents. For DEHP, the age differences were most pronounced. All detectable phthalate biomarker concentrations were positively associated with the levels of the respective phthalate in house dust. In GerES V we found considerably lower phthalate biomarker levels than in the preceding GerES IV (2003-2006). GMs of biomarker levels in GerES V were only 18% (BBzP), 23% (MnBP), 23% (DEHP), 29% (MiBP) and 57% (DiNP) of those measured a decade earlier in GerES IV. However, some children and adolescents still exceeded health-based guidance values in the current GerES V. 0.38% of the participants had levels of DnBP, 0.08% levels of DEHP and 0.007% levels of DiNP which were higher than the respective health-based guidance values. Accordingly, for these persons an impact on health cannot be excluded with sufficient certainty. The ongoing and substantial exposure of vulnerable children and adolescents to many phthalates confirms the need of a continued monitoring of established phthalates, whether regulated or not, as well as of potential substitutes. With this biomonitoring approach we provide a picture of current individual and cumulative exposure developments and body burdens to phthalates, thus providing support for timely and effective chemicals policies and legislation.

Occurrence and Distribution of Phthalates in Sanitary Napkins from Six Countries: Implications for Women's Health

Chemicals in feminine hygiene products can exert adverse health effects as a result of strong absorptive capacity of the vagina and vulva. However, little information is available on phthalates in sanitary napkins. We measured the concentrations of 15 phthalates in sanitary napkins collected from six countries and found total concentrations in the range of 1733-11942 ng/g. Di(isobutyl)phthalate (DiBP), bis(2-ethylhexyl)phthalate (DEHP), and di-n-butyl phthalate (DnBP) were the dominant congeners, representing a median of 27.3, 26.7, and 20.4% of the total median phthalate concentrations across all countries, respectively. The phthalates likely originated mainly from the introduction in the manufacturing process, and some may have been from the use of plastic or paper materials. The estimated intake (at the 90th percentile) of DiBP, DnBP, and DEHP from sanitary napkins approximately represented 6.35-23.6, 3.35-9.90, and 1.06-9.57%, respectively, of the total exposure, indicating that sanitary napkins are a relevant source of exposure to these chemicals. The calculated health risks of phthalates in sanitary napkins were generally low, but the carcinogenic risks in some samples exceeded acceptable levels. More research is required to investigate the contaminations in sanitary napkins and those associated with risks to women.

Investigating exposure to endocrine disruptors via hair analysis of pregnant women

The aim of this study was the monitoring of the levels of parabens (PBs) and triclosan (TCS) in head hair samples of women collected during the first months of their pregnancy. Personal details concerning somatometric and demographic characteristics, dietary habits, use of personal care products and the medical and obstetrical history of the pregnant women as well as infants' somatometric characteristics and health condition were recorded through relevant questionnaires. Ninety five hair samples were collected, extracted by solid-liquid extraction and analysed using a liquid chromatography-mass spectrometry system (LC-MS). Analysis revealed high percentage of positive samples for all tested compounds (90-100% except from BePB (15.8%)). The mean concentration levels were 4501.2 pg/mg (17.6-27,437.0 pg/mg) for MePB; 510.1 pg/mg (11.0-4224.5 pg/mg) for EtPB; 22.9 pg/mg (2.1-66.6 pg/mg) for BePB; 237.1 pg/mg (1.8-2513.7 pg/mg) for BuPB and 245.0 pg/mg (8.8-8070.2 pg/mg) for TCS. Statistical analysis of both analytical results and questionnaires' data showed that the frequent use of personal care and hygiene products, such as makeup, hairspray and sunscreens, is correlated with higher levels of PBs in hair of the pregnant women. Additionally, positive correlation was observed between the BePB levels in hair and the infants' height. Finally, no other correlation was observed between endocrine disruptors' levels in maternal hair and infants' somatometric characteristics or health condition. Our study is the first one that determined PBs and TCS levels in hair samples, simultaneously. At the same time, correlation of the detected levels with the use of personal care products was accomplished, leading to significant association of BePB levels in hair of pregnant women with infants' height.