Personal care product use predicts urinary concentrations of some phthalate monoesters

Mixed-Methods Assessment of Farmworkers' Perceptions of Workplace Compliance with Worker Protection Standards and Implications for Risk Perceptions and Protective Behaviors

INTRODUCTION

The Environmental Protection Agency (EPA)'s Worker Protection Standards is the primary set of legislation aimed at protecting farmworkers from occupational pesticide exposure in the United States. Previous studies suggest that worker adoption of Pesticide Protective Behaviors (PPBs) promoted by WPS is associated with lower urinary pesticide concentrations. However, adoption of PPBs is often outside of the control of individual farmworkers and dependent on workplace factors such as employer provisioning of Personal Protective Equipment (PPE) and access to trainings/resources.

METHODS

We conducted a mixed-method study including urinary pesticide biomonitoring, surveys, and interviews with 62 Latinx farmworkers in southwestern Idaho from April to July 2022. We integrated findings across the various data sources to identify emergent themes relating to farmworkers' perceptions of workplace compliance with WPS and potential implications for their pesticide risk perceptions, protective behaviors, and urinary pesticide concentrations.

RESULTS

Participants reported some indications of poor workplace compliance with WPS regulations, notably inconsistent access to clean handwashing stations and notification of pesticide applications. Some farmworkers, particularly pesticide applicators, viewed herbicides to be categorically safer than other classes of pesticides such as insecticides; these perceptions appeared to influence protective behaviors, such as the relatively low use of PPE while applying herbicides. These findings are underscored by the higher concentrations of biomarkers of herbicides, but not insecticides, among pesticide applicators compared with non-applicators (e.g. median 2,4-D concentrations = 1.40 µg/L among applicators and 0.69 µg/L among non-applicators). Participants further reported concerns regarding the inadequacy of pesticide safety training, pesticide drift, and the lack of communication regarding pesticide applications on and near fields where they are working.

DISCUSSION

Participants' perceptions that herbicides are categorically safer than other pesticide classes is in direct conflict with WPS training, raising concerns about discrepancies between WPS instruction and other on-the-job training, as well as the inadequate provisioning of PPE during the application of certain pesticides. Our findings also suggest that current WPS regulations may not sufficiently address farmworkers' concerns, particularly in regard to pesticide drift.

Associations of concentrations of eight urinary phthalate metabolites with the frequency of use of common adult consumer and personal-care products

This study analyzed the relationship between urine concentrations of phthalate metabolites (UCOM) and personal care products (PCPs) used in adults and examined the change in UCOM according to the usage frequency of PCPs based on raw data from the 3rd Korean National Environmental Health Survey conducted between 2015 and 2017. The relationship between PCP use frequency and UCOM was analyzed using multiple regression analysis, adjusting for baseline factors. The regression model consisted of a Crude Model with log-transformed UCOM before and after adjustment for urine creatinine concentrations. Model 1 was additionally adjusted for age, sex, and obesity, while Model 2 was additionally adjusted for smoking, alcohol consumption, pregnancy history, average monthly income of the household, and PCP exposure within the past 2 days. PCP usage frequency was significantly associated with the UCOM without adjustment for urine creatinine and correlated with demographic characteristics, urine creatinine concentration, and PCP exposure within the past 2 days. This study on exposure to urinary phthalates will play a crucial role in Korean public health by aligning with the fundamentals of research priorities and providing representative data on phthalate exposure for conducting population-level studies.

Patterns of urinary organophosphate ester metabolite trajectories in children: the HOME Study

BACKGROUND

Organophosphate esters (OPEs) have replaced flame retardant polybrominated diphenyl ethers as flame retardants in consumer products, but few longitudinal studies have characterized childhood OPE exposure.

OBJECTIVE

We aimed to examine the exposure pattern of urinary OPE metabolites in children.

METHODS

We quantified three urinary OPE metabolites five times in children (1, 2, 3, 5, 8 years) from 312 mother-child pairs in the Health Outcomes and Measures of the Environment (HOME) Study, a prospective pregnancy and birth cohort in Cincinnati, Ohio, USA. We examined the associations of average maternal OPE metabolite concentrations with OPE metabolite concentrations in childhood, characterized childhood OPE trajectories with latent class growth analysis (LCGA), and examined factors related to trajectory membership.

RESULTS

Bis(2-chloroethyl) phosphate (BCEP) had the lowest median concentrations over time (0.66-0.97 mg/L) while the median concentrations of bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) increased with age (1.44-3.80 mg/L). The median concentrations of diphenyl phosphate (DPHP) fluctuated between 1.96 and 2.69 mg/L. Intraclass correlation coefficients for urinary metabolites measured at five time points indicated high variability within individuals (0.13-0.24). Average maternal urinary BCEP and BDCIPP were associated with concentrations in early childhood. Maternal education, the birth year of the child, and having a carpet in the main activity room were associated with BCEP and BDCIPP trajectory while none of the factors were associated with DPHP trajectory.

SIGNIFICANCE

The trajectory analysis showed different patterns of urinary OPE metabolite concentrations, suggesting the need to collect multiple samples to adequately reflect OPE exposure.

IMPACT STATEMENT

In this well-established cohort, we evaluated the patterns of urinary OPE metabolites in children ages 1-8 years. The number of repeated measures over childhood has not been achieved in prior studies. Our results suggested the high variability of urinary OPE metabolites within individuals. Maternal metabolite concentrations during pregnancy were related to child concentrations at ages 1-3 years. BCEP, BDCIPP, and DPHP demonstrated different trajectories in children, which suggests that multiple samples may be required to capture OPE exposure patterns in childhood.

Co-exposure to 55 endocrine-disrupting chemicals linking diminished sperm quality: Mixture effect, and the role of seminal plasma docosapentaenoic acid

Isolated effects of single endocrine-disrupting chemicals (EDCs) on male reproductive health have been studied extensively, but their mixture effect remains unelucidated. Previous research has suggested that consuming diet enriched in omega-3 polyunsaturated fatty acids (PUFA) might be beneficial for reproductive health, whether omega-3 PUFA could moderate the effect of EDCs mixture on semen quality remains to be explored. In this study of 155 male recruited from a reproductive health center in China, we used targeted-exposomics to simultaneously measure 55 EDCs in the urine for exposure burden. Regression analyses were restricted to highly detected EDCs (≥55%, n = 34), and those with consistently elevated risk were further screened and brought into mixture effect models (Bisphenol A, ethyl paraben, methyl paraben [MeP], benzophenone-1 [BP1], benzophenone-3, mono(3-carboxypropyl) phthalate [MCPP]). Bayesian Kernel Machine Regression (BKMR) and quantile-based g-computation (QGC) models demonstrated that co-exposure to top-ranked EDCs was related to reduced sperm total (β = -0.18, 95%CI: -0.29 - -0.07, P = 0.002) and progressive motility (β = -0.27, 95%CI: -0.43 - -0.10, P = 0.002), but not to lower semen volume. BP1, MeP and MCPP were identified as the main effect driver for deteriorated sperm motion parameters using mixture model analyses. Seminal plasma fatty acid profiling showed that high omega-3 PUFA status, notably elevated docosapentaenoic acid (DPA, C22:5n-3) status, moderated the association between MCPP and sperm motion parameters (total motility: β = 0.26, 95%CI: 0.01 - -0.51, Pinteraction = 0.047; progressive motility: β = 0.64, 95%CI: 0.23 - 1.05, Pinteraction = 0.003). Co-exposure to a range of EDCs is mainly associated with deteriorated sperm quality, but to a lesser extent on sperm quantity, high seminal plasma DPA status might be protective against the effect. Our work emphasizes the importance of exposomic approach to assess chemical exposures and highlighted a new possible intervention target for mitigating the potential adverse effect of EDCs on semen quality.

Prenatal exposure to organophosphate esters and growth trajectory in early childhood

Maternal exposure to organophosphate esters (OPEs) has been linked to an increased risk of adverse birth outcomes. However, the impact of OPEs on childhood growth remains uncertain. This study assessed the associations between prenatal concentrations of OPE metabolites and the growth trajectory in early childhood. 212 singleton pregnant women were included in this study, and they were recruited between August 2014 and August 2016 in Wuhan, China. We measured the urinary concentrations of OPE metabolites during the 1st, 2nd, and 3rd trimesters. Standard deviation scores for weight and length were calculated for children at birth, 1, 6, 12, and 24 months. Trajectories of weight-for-age z-score (WAZ) and weight-for-length z-score (WLZ) were classified into four groups using group-based trajectory modeling. Trajectories of length-for-age z-score (LAZ) were classified into three groups with the same model. Then, we calculated odds ratios (ORs) and 95 % confidence interval (95%CI) using multinomial logistic regression to estimate increases in odds of different growth trajectories per doubling in OPE concentrations compared with moderate-stable trajectory. For average concentrations of OPE metabolites and growth trajectory, our results indicated that higher bis(2-butoxyethyl) phosphate, total aromatic OPE metabolites, and total OPE metabolites during pregnancy were associated with a higher likelihood of children falling into the low-stable and low-rising WAZ trajectory. Furthermore, compared to the moderate-stable LAZ trajectory, increased concentrations of 1-hydroxy-2-propyl bis(1-chloro-2-propyl) phosphate were linked to an elevated risk of a low-stable LAZ trajectory. Additionally, the 1st and 2nd trimesters may represent critical windows of heightened vulnerability to the effects of OPE metabolites on childhood growth. In conclusion, our study proves that prenatal exposure to OPE metabolites is inversely related to childhood growth. It is essential to conduct further research involving larger populations and to consider other compounds with known developmental toxicity to obtain more reliable and comprehensive results.

Evaluating Mixtures of Urinary Phthalate Metabolites and Serum Per-/Polyfluoroalkyl Substances in Relation to Adolescent Hair Cortisol: The HOME Study

Results of toxicological studies indicate that phthalates and per-/polyfluoroalkyl substances (PFAS), 2 classes of endocrine-disrupting chemicals, may alter the functioning of the hypothalamic-pituitary-adrenocortical (HPA) axis. We evaluated the associations of urinary phthalate metabolites and serum PFAS during gestation and childhood with adolescent hair cortisol concentrations (pg/mg hair) at age 12 years, an integrative marker of HPA axis activity (n = 205 mother-child pairs; Cincinnati, Ohio; enrolled 2003-2006). We used quantile-based g-computation to estimate associations between mixtures of urinary phthalate metabolites or serum PFAS and hair cortisol. We also examined whether associations of individual phthalate metabolites or PFAS with cortisol varied by the timing of exposure. We found that a 1-quartile increase in all childhood phthalate metabolites was associated with 35% higher adolescent hair cortisol (phthalate mixture ψ = 0.13; 95% confidence interval: 0.03, 0.22); these associations were driven by monoethyl phthalate, monoisobutyl phthalate, and monobenzyl phthalate. We did not find evidence that phthalate metabolites during gestation or serum PFAS mixtures were related to adolescent hair cortisol concentrations. We found suggestive evidence that higher childhood concentrations of individual PFAS were related to higher and lower adolescent hair cortisol concentrations. Our results suggest that phthalate exposure during childhood may contribute to higher levels of chronic HPA axis activity.

Fluoride exposure and thyroid hormone levels in pregnancy: The MIREC cohort

BACKGROUND

Fluoride exposure may increase the risk of hypothyroidism, but results from previous studies are inconsistent at low-level fluoride exposure (i.e., ≤0.7 mg/L). Human studies of fluoride and thyroid hormone levels in pregnancy are scarce.

OBJECTIVES

We examined associations between fluoride exposure and maternal thyroid hormone levels in a Canadian pregnancy cohort, with consideration for fetal sex-specific effects.

METHODS

We measured fluoride concentrations in drinking water and spot urine samples collected during each trimester from 1876 pregnant women enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) study. We also measured maternal thyroid stimulating hormone (TSH), free thyroxine (FT4), and total thyroxine (TT4) levels during the first trimester of pregnancy. We used linear and non-linear regression models to estimate associations between fluoride exposure and levels of TSH, FT4, and TT4. We explored effect modification by fetal sex and considered maternal iodine status as a potential confounder.

RESULTS

A 1 mg/L increase in urinary fluoride was associated with a 0.30 (95 %CI: 0.08, 0.51) logarithmic unit (i.e., 35.0 %) increase in TSH among women pregnant with females, but not males (B = 0.02; 95 %CI: -0.16, 0.19). Relative to women with urinary fluoride concentrations in the first quartile (0.05-0.32 mg/L), those with levels in the third quartile (0.49-0.75 mg/L) had higher FT4 and TT4 (i.e., inverted J-shaped associations), but the association was not statistically significant after adjustment for covariates (p = 0.06). Water fluoride concentration showed a U-shaped association with maternal FT4, whereby women with water fluoride concentrations in the second (0.13-0.52 mg/L) and third (0.52-0.62 mg/L) quartiles had significantly lower FT4 compared to those with levels in the first quartile (0.04-0.13 mg/L). Adjustment for maternal iodine status did not change the results.

DISCUSSION

Fluoride exposure was associated with alterations in maternal thyroid hormone levels, the magnitude of which appeared to vary by fetal sex. Given the importance of maternal thyroid hormones for fetal neurodevelopment, replication of findings is warranted.

Associations of intrauterine exposure to manganese with fetal and early-childhood growth: a prospective prenatal cohort study

Prenatal manganese (Mn) exposure may be related to poor birth outcomes; however, there are few relevant epidemiological reports on the effects of intrauterine Mn levels on intrauterine fetal and early childhood growth. From 2013 to 2016, 2082 pairs of mothers and infants were recruited in Wuhan, China, who provided an entire set of urine samples during their first, second, and third trimesters. Fetal head circumference (HC), abdominal circumference (AC), femoral length (FL), and estimated fetal weight (EFW) were obtained by ultrasound at the 16, 24, and 31 weeks of pregnancy. When the children were born, 6 months old, 12 months old, and 24 months old, their weight, height, weight-for-height, and BMI were measured. We used generalized linear models, generalized estimated equations, and restricted cubic spline curves (RCS) to investigate the linear and nonlinear relationships between antenatal Mn levels and fetal and early childhood growth. In all fetuses, Mn exposure during the 1st and 2nd gestation was associated with decreased fetal AC, FL, and EFW at 24 weeks (e.g., for each doubling of urinary Mn concentrations during the 1st and 2nd gestation, the SD score of EFW at 24 weeks decreased by - 4.16% (95% CI, - 6.22%, - 2.10%) and - 3.78% (95% CI, - 5.86%, - 1.70%)). Mn concentrations in the highest tertile group of the 1st and 2nd gestation were related to decreased fetus growth parameters compared to the lowest tertile group. For each doubling of the average Mn concentrations during pregnancy, the z-scores of weight, weight-for-height, and BMI at 12 months decreased, with percentage changes of - 2.93% (95% CI, - 5.08%, - 0.79%), - 3.25% (95% CI, - 5.56%, - 0.94%), and - 3.09% (95% CI, - 5.44%, - 0.73%). In the RCS model, we found a reverse U-shaped association between 1st trimester Mn concentration and fetal FL at 16 weeks and HC at 31 weeks in male fetuses and a non-linear association between mean Mn concentration during pregnancy and girls' weight-for-height and BMI at 6 months. Intrauterine exposure to Mn may be related to restricted growth in the fetus and early childhood, especially in fetuses at 24 weeks of gestation and children at 12 months of age. Also, meaningful curvilinear relationships were found in the sex stratification.

Examination of urinary pesticide concentrations, protective behaviors, and risk perceptions among Latino and Latina farmworkers in Southwestern Idaho

INTRODUCTION

Studies have documented high levels of pesticide exposure among men farmworkers; however, few have examined exposures or the experiences of women farmworkers. Data gaps also exist regarding farmworkers' perceived risk and control related to pesticides, information that is critical to develop protective interventions.

OBJECTIVE

We aimed to compare urinary pesticide biomarker concentrations between Latino and Latina farmworkers and examine associations with occupational characteristics, risk perceptions, perceived control, and protective behaviors.

METHODS

We enrolled a convenience sample of 62 farmworkers (30 men and 32 women) during the pesticide spray season from April-July 2022 in southwestern Idaho. Participants were asked to complete two visits within a seven-day period; at each visit, we collected a urine sample and administered a questionnaire assessing demographic and occupational information. Urine samples were composited and analyzed for 17 biomarkers of herbicides and of organophosphate (OP) and pyrethroid insecticides.

RESULTS

Ten pesticide biomarkers (TCPy, MDA, PNP, 3-PBA, 4-F-3-PBA, cis- and trans-DCCA, 2,4-D, Glyphosate, AMPA) were detected in >80% of samples. Men and women had similar urinary biomarker concentrations (p = 0.19-0.94); however, women worked significantly fewer hours than men (p = 0.01), wore similar or greater levels of Personal Protective Equipment (PPE), and were slightly more likely to report having experienced an Acute Pesticide Poisoning (26% of women vs. 14% of men; p = 0.25). We observed inconsistencies in risk perceptions, perceived control, and protective behaviors among men.

DISCUSSION

Our study is one the first to examine pesticide exposure and risk perceptions among a cohort of farmworkers balanced on gender. Taken with previous findings, our results suggest that factors such as job tasks, biological susceptibility, or access to trainings and protective equipment might uniquely impact women farmworkers' exposure and/or vulnerability to pesticides. Women represent an increasing proportion of the agricultural workforce, and larger studies are needed to disentangle these findings.

A Gender Hypothesis of sex disparities in adverse drug events

Pharmacovigilance databases contain larger numbers of adverse drug events (ADEs) that occurred in women compared to men. The cause of this disparity is frequently attributed to sex-linked biological factors. We offer an alternative Gender Hypothesis, positing that gendered social factors are central to the production of aggregate sex disparities in ADE reports. We describe four pathways through which gender may influence observed sex disparities in pharmacovigilance databases: healthcare utilization; bias and discrimination in the clinic; experience of a drug event as adverse; and pre-existing social and structural determinants of health. We then use data from the U.S. FDA Adverse Event Reporting System (FAERS) to explore how the Gender Hypothesis might generate novel predictions and explanations of sex disparities in ADEs in existing widely referenced datasets. Analyzing more than 3 million records of ADEs between 2014 and 2022, we find that patient-reported ADEs show a larger female skew than healthcare provider-reported ADEs and that the sex disparity is markedly smaller for outcomes involving death or hospitalization. We also find that the sex disparity varies greatly across types of ADEs, for example, cosmetically salient ADEs are skewed heavily female and sexual dysfunction ADEs are skewed male. Together, we interpret these findings as providing evidence of the promise of the Gender Hypothesis for identifying intervenable mechanisms and pathways contributing to sex disparities in ADEs. Rigorous application of the Gender Hypothesis to additional datasets and in future research studies could yield new insights into the causes of sex disparities in ADEs.

Synthetic Chemicals: What We Have Learned and Still Need to Learn About Their Associations with Childhood Allergy and Asthma

PURPOSE OF REVIEW

Prenatal and childhood exposure to synthetic chemicals, such as phenols and phthalates, have been linked to asthma and allergy, but the extent of this association and the underlying mechanisms are not fully understood. Here we provide an up-to-date review of the evidence linking phenol and phthalate exposure with childhood asthma and allergy and of proposed mechanistic pathways.

RECENT FINDINGS

Five experimental and 12 epidemiological studies that examined associations between exposures to synthetic chemicals to asthma and allergic diseases were included. An additional 14 studies provided mechanistic support for the importance of immune modification through epigenetic regulation, induction of pro-allergic T2 expression, and endocrine disruption. While recent studies have provided further experimental and epidemiological evidence for how these chemical exposures may induce childhood asthma and allergy, the recent literature remains limited. However, emerging mechanistic studies have identified chemical-induced alterations in DNA methylation of genes implicated in allergic inflammation and endocrine disruption as potential pathways. In addition, barriers to decrease exposure to synthetic chemicals at the individual level (facilitated through education) and areas for further action at the organizational and governmental levels are suggested. The latter includes transferring some of the onus from the individual to organizations and legislation to restrict marketing and access to products containing potentially harmful chemicals and provide alternative products. We also suggest future research that focuses on further elucidating pathways between exposure to disease development and identifying strategies to reduce exposure at the population level.

Epidemiology and Risk Factors for Breast Cancer: 21st Century Advances, Gaps to Address through Interdisciplinary Science

Research methods to study risk factors and prevention of breast cancer have evolved rapidly. We focus on advances from epidemiologic studies reported over the past two decades addressing scientific discoveries, as well as their clinical and public health translation for breast cancer risk reduction. In addition to reviewing methodology advances such as widespread assessment of mammographic density and Mendelian randomization, we summarize the recent evidence with a focus on the timing of exposure and windows of susceptibility. We summarize the implications of the new evidence for application in risk stratification models and clinical translation to focus prevention-maximizing benefits and minimizing harm. We conclude our review identifying research gaps. These include: pathways for the inverse association of vegetable intake and estrogen receptor (ER)-ve tumors, prepubertal and adolescent diet and risk, early life adiposity reducing lifelong risk, and gaps from changes in habits (e.g., vaping, binge drinking), and environmental exposures.

A descriptive analysis of first trimester urinary concentrations of 14 bisphenol analogues in the MIREC Canadian pregnancy cohort

BACKGROUND

Concern over the health effects of BPA, particularly for the developing fetus, has led to an increasing use of bisphenol analogues in industrial and consumer products, which may be as hormonally active as BPA. Biomonitoring data for many bisphenol analogues, especially in pregnant populations, are limited.

METHODS

We measured concentrations of 14 bisphenol analogues in 1st trimester urine samples (n = 1851) from the Maternal-Infant Research on Environmental Chemicals (MIREC) Canadian pregnancy cohort (2008-2011). We examined patterns of exposure according to sociodemographic and sampling characteristics as well as occupation and frequency of consumption of canned fish within the previous 3 months.

RESULTS

BPA was detected in 89% of participants with a specific gravity standardized geometric mean concentration of 0.990 μg/L. Biphenol 4,4' (BP 4,4'), 4,4'-dihydroxydiphenyl ether (DHDPE), and bisphenol E (BPE) were detected in >97% of participants. Bisphenol F (BPF) and bisphenol S (BPS) were detected in >60% of participants. Specific gravity standardized geometric mean concentrations of these 5 compounds ranged from 0.024 to 0.564 μg/L. Nine bisphenol analogues were detected in <9% of participants. Concentrations of BP 4,4', DHDPE, and BPE were higher in younger women and those with higher pre-pregnancy BMI, lower household income, lower education, and among smokers. We found a similar pattern of differences in BPF for age, education, and smoking status while BPS similarly differed across categories of pre-pregnancy BMI. Participants who were unemployed or working in the service industry had higher molar sum of 7 bisphenol analogues than those working in healthcare, education, or an office setting. Canned fish consumption was not related to bisphenol analogue concentrations.

CONCLUSION

BP 4,4', DHDPE, BPE, BPF, and BPS were highly detected in 1st trimester urine samples in this large pan-Canadian pregnancy cohort. This suggests widespread exposure to these analogues around 2008-2011 and warrants further investigation into associations with health outcomes.

The mediating role of telomere length in multi-pollutant exposure associated with metabolic syndrome in adults

Metabolic syndrome is a chronic and complex disease characterized by environmental and genetic factors. However, the underlying mechanisms remain unclear. This study assessed the relationship between exposure to a mixture of environmental chemicals and metabolic syndrome (MetS) and further examined whether telomere length (TL) moderated these relationships. A total of 1265 adults aged > 20 years participated in the study. Data on multiple pollutants (polycyclic aromatic hydrocarbons, phthalates, and metals), MetS, leukocyte telomere length (LTL), and confounders were provided in the 2001-2002 National Health and Nutrition Examination Survey. The correlations between multi-pollutant exposure, TL, and MetS in the males and females were separately assessed using principal component analysis (PCA), logistic and extended linear regression models, Bayesian kernel machine regression (BKMR), and mediation analysis. Four factors were generated in PCA that accounted for 76.2% and 77.5% of the total environmental pollutants in males and females, respectively. The highest quantiles of PC2 and PC4 were associated with the risk of TL shortening (P < 0.05). We observed that the relationship between PC2, PC4, and MetS risk was significant in the participants with median TL levels (P for trend = 0.04 for PC2, and P for trend = 0.01 for PC4). Furthermore, mediation analysis revealed that TL could explain 26.1% and 17.1% of the effects of PC2 and PC4 associated with MetS in males, respectively. The results of BKMR model revealed that these associations were mainly driven by 1-PYE (cPIP = 0.65) and Cd (cPIP = 0.29) in PC2. Meanwhile, TL could explain 17.7% of the mediation effects of PC2 associated with MetS in the females. However, the relationships between pollutants and MetS were sparse and inconsistent in the females. Our findings suggest that the effects of the risk of MetS associated with mixed exposure to multiple pollutants are mediated by TL, and this mediating effect in the males is more pronounced than that in the females.

Urinary Glyphosate Concentrations among Pregnant Participants in a Randomized, Crossover Trial of Organic and Conventional Diets

BACKGROUND

Consumption of an organic diet reduces exposure to a range of agricultural pesticides. Only three studies have examined the effect of an organic diet intervention on exposure to the herbicide glyphosate, the most heavily used agricultural chemical in the world. Despite its widespread use, the primary sources of glyphosate exposure in humans are poorly understood.

OBJECTIVE

Our objective was to examine the effect of an organic diet intervention on urinary glyphosate concentrations among pregnant individuals.

METHODS

We conducted a 2-wk randomized crossover trial in which 39 pregnant participants living near (≤ 0.5 km ) and far (> 0.5 km ) from agricultural fields received a 1-wk supply of conventional groceries and 1 wk of organic groceries, randomized to order. We collected daily first morning void urine samples and analyzed composite samples from each week for glyphosate. We examined differences in urinary glyphosate concentrations between the conventional week and the organic week among all participants and stratified by residential proximity to an agricultural field.

RESULTS

Median specific gravity-adjusted glyphosate concentrations were 0.19 μ g / L and 0.16 μ g / L during the conventional and organic weeks, respectively. We observed modest decreases in urinary glyphosate concentrations from the conventional to organic week among far-field participants, but no difference among near-field participants. In secondary analyses excluding participants who did not meet a priori criteria of compliance with the intervention, we observed significant decreases in urinary glyphosate concentrations, particularly among far-field participants (p < 0.01 - 0.02 , depending on exclusion criteria).

DISCUSSION

This trial is the first to examine the effect of an organic diet intervention on glyphosate among people living near and far from agricultural fields. Our results suggest that diet is an important contributor to glyphosate exposure in people living > 0.5 km from agricultural fields; for people living near crops, agriculture may be a dominant exposure source during the pesticide spray season. https://doi.org/10.1289/EHP12155.

Early-life exposure to a mixture of organophosphate esters and child behavior

Organophosphate esters (OPEs), widely used as flame retardants and plasticizers for commercial and residential purposes, are suspected of being neurotoxic. We aimed to assess exposure to an OPE mixture in early life and its relationship to parent-reported child behavior. We measured urinary concentrations of three OPE metabolites, bis-2-chloroethyl phosphate (BCEP), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), and diphenyl phosphate (DPHP), at pregnancy (16 and 26 weeks of gestation and delivery) and postnatal time points (ages 1, 2, 3, and 5 years) in the Health Outcomes and Measures of the Environment Study, a longitudinal pregnancy and birth cohort in Cincinnati, Ohio, USA (enrolled 2003-2006, n = 219). We used latent variable analysis in structural equations models and quantile g-computation to investigate associations of a mixture of the three OPE metabolites with parent-reported child behaviors at 3 and 8 years, measured using the Behavioral Assessment System for Children, Second Edition. Higher log-transformed urinary OPE latent variable values at 16 weeks were associated with fewer externalizing problem behaviors (ß = -5.74; 95% CI = -11.24, -0.24) and fewer overall behavioral problems at age 3 years (ß = -5.26; 95% CI = -10.33, -0.19), whereas having higher OPEs at delivery was associated with poorer overall behavioral problems at age 3 years (ß = 2.87; 95% CI = 0.13, 5.61). OPE latent variable values at 16 weeks, 26 weeks, and delivery were not associated with child behavior at 8 years. However, higher OPE latent variable values at 3 years were associated with fewer externalizing behaviors at 8 years (ß = -2.62; 95% CI = -5.13, -0.12). The quantile g-computation estimates had directions largely consistent with the latent variable analysis results. Pregnancy and postnatal urinary OPE metabolite mixtures were associated with child internalizing, externalizing, and overall negative behaviors at 3 and 8 years, but we did not identify a consistent pattern in terms of the direction of the effects or a particularly sensitive time point.

Fluoride exposure and hypothyroidism in a Canadian pregnancy cohort

BACKGROUND

While fluoride can have thyroid-disrupting effects, associations between low-level fluoride exposure and thyroid conditions remain unclear, especially during pregnancy when insufficient thyroid hormones can adversely impact offspring development.

OBJECTIVES

We evaluated associations between fluoride exposure and hypothyroidism in a Canadian pregnancy cohort.

METHODS

We measured fluoride concentrations in drinking water and three dilution-corrected urine samples and estimated fluoride intake based on self-reported beverage consumption. We classified women enrolled in the Maternal-Infant Research on Environmental Chemicals Study as euthyroid (n = 1301), subclinical hypothyroid (n = 100) or primary hypothyroid (n = 107) based on their thyroid hormone levels in trimester one. We used multinomial logistic regression to estimate the association between fluoride exposure and classification of either subclinical or primary hypothyroidism and considered maternal thyroid peroxidase antibody (TPOAb) status, a marker of autoimmune hypothyroidism, as an effect modifier. In a subsample of 466 mother-child pairs, we used linear regression to explore the association between maternal hypothyroidism and child Full-Scale IQ (FSIQ) at ages 3-to-4 years and tested for effect modification by child sex.

RESULTS

A 0.5 mg/L increase in drinking water fluoride concentration was associated with a 1.65 (95 % confidence interval [CI]: 1.04, 2.60) increased odds of primary hypothyroidism. In contrast, we did not find a significant association between urinary fluoride (adjusted odds ratio [aOR]: 1.00; 95%CI: 0.73, 1.39) or fluoride intake (aOR: 1.25; 95%CI: 0.99, 1.57) and hypothyroidism. Among women with normal TPOAb levels, the risk of primary hypothyroidism increased with both increasing water fluoride and fluoride intake (aOR water fluoride concentration: 2.85; 95%CI: 1.25, 6.50; aOR fluoride intake: 1.75; 95%CI: 1.27, 2.41). Children born to women with primary hypothyroidism had lower FSIQ scores compared to children of euthyroid women, especially among boys (B coefficient: -8.42; 95 % CI: -15.33, -1.50).

DISCUSSION

Fluoride in drinking water was associated with increased risk of hypothyroidism in pregnant women. Thyroid disruption may contribute to developmental neurotoxicity of fluoride.

Descriptive analysis of organophosphate ester metabolites in a pan-Canadian pregnancy cohort

Organophosphate esters (OPEs) are widely used in numerous consumer products for their flame retardant and plasticizing properties. Despite potential widespread exposure, biomonitoring data during critical windows of development are scarce and limited to the most widely studied metabolites. We quantified urinary concentrations of multiple OPE metabolites in a vulnerable Canadian population. Using data and biobanked specimens from the Maternal-Infant Research on Environmental Chemicals (MIREC) study (2008-2011), we measured first trimester urinary concentrations of 15 OPE metabolites as well as one flame retardant metabolite and quantified associations with sociodemographic and sample collection characteristics in 1865 pregnant participants. We applied 2 different analytical methods to quantify OPEs, one using UItra-Performance Liquid Chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) and the other using Atmospheric Pressure Gas Chromatography coupled to mass spectrometry (APGC-MS/MS) with sensitive limits of detection (0.008-0.1 μg/L). We modelled associations between sociodemographic and sample collection characteristics and specific gravity-standardized chemical concentrations. Six OPE metabolites were detected in the majority (68.1-97.4 %) of participants. Bis-(2-chloroethyl) hydrogen phosphate had the highest detection rate (97.4 %). Diphenyl phosphate had the highest geometric mean concentration (0.657 μg/L). Metabolites of tricresyl phosphate were detected in few participants. Associations between sociodemographic characteristics varied according to each OPE metabolite. Pre-pregnancy body mass index tended to be positively associated with OPE metabolite concentrations whereas age tended to be inversely associated with OPE concentrations. OPE concentrations were, on average, higher in urine samples collected in the summer than other seasons the winter. We present the largest biomonitoring study of OPE metabolites in pregnant people to date. These findings demonstrate widespread exposure to OPEs and their metabolites and identify subpopulations who may experience heightened exposure.

Prenatal arsenic exposure, arsenic metabolism and neurocognitive development of 2-year-old children in low-arsenic areas

BACKGROUND

There is limited evidence on the effects of arsenic species and metabolic capacity on child neurodevelopment, particularly at low levels. Further, little is known about the critical window of exposure.

OBJECTIVE

To estimate the associations of arsenic exposure and arsenic metabolism in different pregnancy periods with neurodevelopment of two-year-old children.

METHODS

Concentrations of arsenobetaine (AsB), arsenite, arsenate, monomethyl arsenic acid (MMA), and dimethyl arsenic acid (DMA) in urine samples collected in three trimesters from 1006 mothers were measured using HPLC - ICPMS. Inorganic arsenic (iAs) was calculated as the sum of arsenite and arsenate. Total arsenic (tAs) was calculated as the sum of iAs, MMA and DMA. Child neurodevelopment was assessed with the Bayley Scales of Infant Development.

RESULTS

The geometric mean (GM) of SG-adjusted tAs in the first, second, third trimester was 16.37, 12.94, 13.04 μg/L, respectively. The mental development index (MDI) score was inversely associated with iAs and tAs. Compared to the 1st quartile, the MDI score decreased 0.43 (95%CI: -4.22, 3.36) for the 2nd, 6.50 (95%CI: -11.73, -1.27) for the 3rd, 5.42 (95%CI: -10.74, -0.10) for the 4th quartiles of iAs, and decreased 4.03 (95%CI: -7.90, -0.15) in the 4th quartile of tAs. In trimester-specific models, negative associations of DMA [-1.94 (95%CI: -3.18, -0.71)] and tAs [-1.61 (95%CI: -3.02, -0.20)] with the psychomotor development index (PDI) were only observed in 1st trimester.

CONCLUSIONS

Our study found inverse associations between prenatal arsenic exposure, especially in early pregnancy, and neurodevelopment of children at two years old, even at low exposure levels.

Gestational exposure to organophosphate esters and infant anthropometric measures in the first 4 weeks after birth

BACKGROUND

Few studies have examined whether gestational exposure to organophosphate esters (OPEs), widely used chemicals with potential endocrine-disrupting potency and developmental toxicity, is associated with impaired infant growth.

METHODS

We analyzed data from 329 mother-infant pairs in the Health Outcomes and Measures of the Environment (HOME) Study (2003-2006, Cincinnati, Ohio, USA). We quantified concentrations of four OPE metabolites in maternal urine collected at 16 and 26 weeks of gestation, and at delivery. We calculated z-scores using 2006 World Health Organization (WHO) child growth standards for the 4-week anthropometric measures (weight, length, and head circumference), the ponderal index, and weekly growth rates. We used multiple informant models to examine window-specific associations between individual OPE metabolites and anthropometric outcomes. We further modeled OPEs as a mixture for window-specific associations with 4-week anthropometric outcomes using mean field variational Bayesian inference procedure for lagged kernel machine regression (MFVB-LKMR). We stratified the models by infant sex.

RESULTS

Diphenyl phosphate (DPHP) in mothers at 16 weeks, and bis(2-chloroethyl) phosphate (BCEP) and bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) at delivery were positively associated with z-scores of weight, length, and head circumference in all infants at 4 weeks of age. After stratifying by infant sex, positive associations were only observed in males for DPHP at 16 weeks and BCEP at delivery and in females for BDCIPP at delivery. Negative associations not present in all infants were observed in males for di-n-butyl phosphate (DNBP) at 26 weeks of gestation with weight z-score and DPHP at delivery with head circumference z-score. Results were generally similar using MFVB-LKMR models with more conservative 95 % credible intervals. We did not identify consistent associations of gestational OPE metabolite concentrations with the ponderal index and weekly growth rates.

CONCLUSION

In this cohort, exposure to OPEs during gestation was associated with altered infant anthropometry at 4 weeks after birth.

Urinary concentrations and determinants of glyphosate and glufosinate in pregnant Canadian participants in the MIREC study

BACKGROUND

Glyphosate is the most widely applied herbicide in agriculture. Glufosinate is a broad spectrum herbicide used to manage glyphosate-resistant weeds. Despite the widespread use of these herbicides, biomonitoring data - which inform risk assessment and management - are sparse.

OBJECTIVES

To identify determinants of urinary concentrations of these herbicides and their metabolites in pregnancy.

METHODS

We measured urinary concentrations of glyphosate, glufosinate, and their primary metabolites aminomethylphosphonic acid (AMPA) and 3-methylphosphinicopropionic acid (3-MPPA) in a single spot urine specimen collected during the first trimester of pregnancy from the Maternal-Infant Research on Environmental Chemicals (MIREC) study. MIREC recruited about 2000 pregnant women from 10 Canadian cities between 2008 and 2011. We used UItra-Performance Liquid Chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) with sensitive limits of detection to quantify analyte concentrations. We examined urinary concentrations according to maternal sociodemographics, sample collection characteristics, reported pesticide use, and consumption of fruits, vegetables, legumes, and grain products. We used ANOVA models with specific gravity-standardized chemical concentrations as the dependent variable to determine associations with maternal and sample determinants.

RESULTS

Among women with biobanked urine samples (n = 1829-1854), 74% and 72% had detectable concentrations of glyphosate and AMPA, respectively. In contrast, one and six percent of women had detectable concentrations of glufosinate and 3-MPPA, respectively. The specific gravity-standardized geometric mean (95% CI) concentrations of glyphosate and AMPA were 0.112 (0.099-0.127) μg/L and 0.159 (0.147-0.172) μg/L, respectively. We observed a dose-response relationship between consumption of whole grain bread and higher urinary glyphosate concentrations. Season of urine collection and self-reported pesticide use were not associated with increased concentrations of any analyte.

CONCLUSIONS

We detected glyphosate and AMPA in the majority of pregnant women from this predominantly urban Canadian cohort. Diet was a probable route of exposure.

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.

Inter-method reliability of silicone exposome wristbands and urinary biomarker assays in a pregnancy cohort

Silicone wristbands act as passive environmental samplers capable of detecting and measuring concentrations of a variety of chemicals. They offer a noninvasive method to collect complex exposure data in large-scale epidemiological studies. We evaluated the inter-method reliability of silicone wristbands and urinary biomarkers in the New Hampshire Birth Cohort Study. A subset of study participants (n = 96) provided a urine sample and wore a silicone wristband for 7 days at approximately 12 gestational weeks. Women were instructed to wear the wristbands during all their normal activities. Concentrations of urinary compounds and metabolites in the urine and parent compounds in wristbands were compared. High detection rates were observed for triphenyl phosphate (76.0%) and benzophenone (78.1%) in wristbands, although the distribution of corresponding urinary concentrations of chemicals did not differ according to whether chemicals were detected or not detected in wristbands. While detected among only 8.3% of wristbands, median urinary triclosan concentrations were higher among those with triclosan detected in wristbands (9.04 ng/mL) than without (0.16 ng/mL). For most chemicals slight to fair agreement was observed across exposure assessment methods, potentially due to low rates of detection in the wristbands for chemicals where observed urinary concentrations were relatively low as compared to background concentrations in the general population. Our findings support the growing body of research in support of deploying silicone wristbands as an important exposure assessment tool.

Urinary levels of parabens, phthalate metabolites, bisphenol A and plasticizer alternatives in a Belgian population: Time trend or impact of an awareness campaign?

A human biomonitoring study was carried out in 2015 within an adult population living in Liege (Belgium). Some phthalate metabolites and parabens were measured in the urine of 252 participants, and information were collected about their food habits, life styles and home environment to identify some predictors of exposure. Concomitantly, an awareness campaign was initiated by the Provincial Authorities of Liege and spread over 2 years. Three years later (2018), 92 of the initial participants provided again urine samples, and the levels of phthalate metabolites, phthalate substitute (DINCH), parabens, bisphenol-A and bisphenol alternatives (bisphenol-S, -F, -Z, -P) were determined and compared to those obtained in 2015 to assess time trends. In 2015, methyl- and ethylparaben were the most abundant parabens (P50 = 9.12 μg/L and 1.1 μg/L respectively), while propyl- and butylparaben were sparsely detected. Except for mono-2-ethylhexyl phthalate and 6-OH-mono-propyl-heptyl phthalate, all other targeted phthalate metabolites were positively quantified in most of the urine samples (between 89 and 98%) with median concentrations ranging between 2.7 μg/L and 21.3 μg/L depending on the metabolite. The multivariate regression models highlighted some significant associations between urinary phthalate metabolite or paraben levels and age, rural or urban character of the residence place, and the use of some personal care products. However, all determination coefficients were weak meaning that the usual covariates included in the models only explained a small part of the variance. Between 2015 and 2018, levels of parabens and phthalate metabolites significantly decreased (from 1.3 to 2.5 fold) except for monoethyl phthalate which seemed to remain quite constant. Contrariwise, all bisphenol alternatives and DINCH metabolites were measured in higher concentrations in 2018 vs 2015 while BPA levels did not differ significantly. However, it was not feasible to unequivocally highlight an impact of the awareness campaign on the exposure levels of the population.

Physiologically-based toxicokinetic modeling of human dermal exposure to diethyl phthalate: Application to health risk assessment

Diethyl phthalate (DEP) has been most frequently detected in personal care products (PCPs) as a solvent followed by indoor air as one of the semi-volatile organic compounds (SVOCs). Human exposure to DEP predominantly occurs via dermal uptake. However, the available physiologically based toxicokinetics (PBTK) models are developed in rats for risk assessment of DEP exposure resulting from the oral than dermal pathway. To address this issue, DEP in simulated PCPs was dermally administrated to five adult volunteers at real population levels. Following the construction of a dermal absorption model for DEP, the dermal PBTK modeling of DEP involving PCPs and air-to-skin exposure routes in humans was developed for the first time. The data of monoethyl phthalate (MEP) in serum or urine obtained from published human studies and this study were applied to calibrate and validate the developed dermal PBTK model. Monte Carlo simulation was used to evaluate model uncertainty. The dermal absorption fraction of DEP was obtained to be 56.2% for PCPs exposure and 100% for air-to-skin exposure, respectively. Approximate 24.9% of DEP in exposed skin became absorbed into systemic circulation. Model predictions were generally within 2-fold of the observed MEP levels in human serum or urine. Uncertainty analysis showed 90% of the predicted variability (P₉₅/P₅) fell within less than one order of magnitude. Assuming human intake of 5 mg/kg bw per day, the predicted serum area under the curve at steady state of DEP from the dermal route was 1.7 (PCPs) and 2.4 (air) times of those from the peroral route, respectively. It suggested that dermal exposure to DEP would pose greater risk to human health compared with oral exposure. The application of the developed dermal PBTK model provides a valuable insight into health risk assessment of DEP in humans.

Common Chemical Pollutants Causing a Lot of Ill Health

Due to industrialization and inadequate controls on release of manufacturing chemicals into the environment and into the products being made, the entire population is constantly being exposed to a wide variety of chemical pollutants. The key question, of course, is their safety. The most acutely damaging ones have been progressively limited. However, virtually all safety research is on single toxins and very little of it looks at the impact of chronic exposure, especially chronic exposure to multiple chemicals simultaneously. This editorial discusses the clinical significance of 4 of the chemicals (acrolein, acrylamide, perchlorate, and phthalates) found most often in samples doctors send to labs for analysis. The research clearly demonstrates that these chemicals in a dose-dependent manner disrupt physiology, impair health, and increase risk for common diseases.

National-scale urinary phthalate metabolites in the general urban residents involving 26 provincial capital cities in China and the influencing factors as well as non-carcinogenic risks

Phthalates (PAEs) are widely used in daily products but can cause a variety of adverse effects in humans. Few studies have been carried out on human internal exposure levels of PAEs on a large-scale, especially in developing countries. In the present study, 1161 urine samples collected from residents of 26 provincial capitals in China were analyzed for nine phthalate metabolites (mPAEs). The chemicals were widely detected, and the median specific gravity adjusted urinary concentration of Σ₉mPAEs was 278 μg/L. Di-(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) were the main parent PAEs that the residents were exposed to. Demographic characteristics, such as age and educational level, were significantly associated with PAE exposure. Children and the elderly had higher mPAE levels. Subjects with lower educational levels were more frequently exposed to DnBP and DEHP. However, mono-ethyl phthalate showed the opposite trend, i.e., higher concentrations in subjects aged 18-59 years and with higher educational levels. Geographic differences were detected at the national scale. Residents in northeastern and western China had higher levels of mPAEs than those in central China, most likely because of different industrial usage of the chemicals and different living habits and living conditions of the residents. Health risk assessment showed that hazard indices of PAEs ranged from 0.07 to 9.34, with 20.0% of the subjects being concern for potential non-carcinogenic risk as assessed by Monte Carlo simulation. DEHP and DnBP were the primary contributors, representing 96.7% of total risk. This first large-scale study on PAE human internal exposure in China provides useful information on residents' health in a developing country, which could be used for chemical management and health protection.

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.

Associations of prepubertal urinary phthalate metabolite concentrations with pubertal onset among a longitudinal cohort of boys

BACKGROUND

Although phthalate exposures have been associated with adverse effects on male reproductive health, few studies have explored longitudinal associations with male pubertal development.

OBJECTIVES

We examined the association of prepubertal urinary concentrations of phthalate metabolites with age at pubertal onset in a prospective cohort of Russian boys.

METHODS

At enrollment at ages 8-9 years, medical history, dietary, and demographic information was collected. At entry and annually, physical examinations and pubertal staging [Genitalia (G), Pubarche (P), and testicular volume (TV, in ml)] were conducted and spot urines were collected. Prepubertal urine samples (defined as either TV = 1, 2 and G = 1, 2 or TV = 3 and G = 1) were pooled for each boy and phthalate metabolite concentrations were quantified using isotope dilution LC-MS/MS at Moscow State University. We measured 15 metabolites including those from anti-androgenic parent phthalates (AAPs) such as di (2-ethylhexyl) (DEHP) and di-isononyl (DiNP) phthalates as well as monobenzyl (MBzP), mono-n-butyl (MnBP), and mono-isobutyl (MiBP) metabolites. We calculated the molar sums of DEHP (∑DEHP), DiNP (∑DiNP), and AAP (∑AAP) metabolites. Separate interval-censored models were used to assess associations of quartiles of prepubertal phthalate metabolites with each pubertal onset indicator, G2+, P2+ and TV > 3 mL, adjusted for covariates and urine specific gravity.

RESULTS

304 boys had 752 prepubertal urine samples (median 2, range: 1-6) for pooling. In adjusted models, higher urinary AAPs were consistently associated with later pubertal onset (P2) with mean shifts ranging from 8.4 to 14.2 months for the highest versus lowest quartiles. Significantly later onset for G2 and TV > 3 mL was observed for higher versus lower quartiles of MiBP, MBzP, ∑DEHP and ∑DiNP.

CONCLUSIONS

On average, boys with higher concentrations of prepubertal urinary AAPs had later pubertal onset by six months to over a year. The impact of AAPs on timing of male puberty may be attributable to disruption of androgen-dependent biological pathways.

Evidence-Based Interventions for Reducing Breast Cancer Disparities: What Works and Where the Gaps Are?

The National Cancer Institute (NCI) has established an online repository of evidence-based cancer control programs (EBCCP) and increasingly calls for the usage of these EBCCPs to reduce the cancer burden. To inventory existing EBCCPs and identify remaining gaps, we summarized NCI's EBCCPs relevant to reducing breast cancer risk with an eye towards interventions that address multiple levels of influence in populations facing breast cancer disparities. For each program, the NCI EBCCP repository provides the following expert panel determined summary metrics: (a) program ratings (1-5 scale, 5 best) of research integrity, intervention impact, and dissemination capability, and (b) RE-AIM framework assessment (0-100%) of program reach, effectiveness, adoption, and implementation. We quantified the number of EBCCPs that met the quality criteria of receiving a score of ≥3 for research integrity, intervention impact, and dissemination capability, and receiving a score of ≥50% for available RE-AIM reach, effectiveness, adoption, and implementation. For breast cancer risk reduction, we assessed the presence and quality of EBCCPs related to physical activity (PA), obesity, alcohol, tobacco control in early life, breastfeeding, and environmental chemical exposures. Our review revealed several major gaps in EBCCPs for reducing the breast cancer burden: (1) there are no EBCCPs for key breast cancer risk factors including alcohol, breastfeeding, and environmental chemical exposures; (2) among the EBCPPs that exist for PA, obesity, and tobacco control in early life, only a small fraction (24%, 17% and 31%, respectively) met all the quality criteria (≥3 EBCCP scores and ≥50% RE-AIM scores) and; (3) of those that met the quality criteria, only two PA interventions, one obesity, and no tobacco control interventions addressed multiple levels of influence and were developed in populations facing breast cancer disparities. Thus, developing, evaluating, and disseminating interventions to address important risk factors and reduce breast cancer disparities are needed.

Urinary phthalate metabolite concentrations and personal care product use during pregnancy - Results of a pilot study

INTRODUCTION

Phthalates are reproductive toxicants commonly found in personal care products (PCPs). These endocrine disrupting chemicals are associated with pregnancy complications, including gestational diabetes. Yet, little is known about PCP use as a contributor to urinary phthalate metabolite concentrations in pregnancy.

METHODS

We conducted a pilot study among 108 pregnant participants to examine the associations of self-reported PCP use with 14 phthalate and 2 DINCH (di(isononyl) cyclohexane-1,2-dicarboxylate) metabolite concentrations measured in single spot urine samples during pregnancy (median: 36 weeks of gestation). At the time of urine collection, participants self-reported use of hair products (within the last month) and other PCPs (within the last 48 h). We used linear regression to estimate associations for natural log-transformed, specific gravity-corrected concentrations of common PCP-associated phthalate metabolites (monoethyl phthalate [MEP], mono-n-butyl phthalate [MBP], and mono-isobutyl phthalate [MIBP]) in our primary analyses, and additional phthalate metabolites in secondary analyses.

RESULTS

Most urinary metabolites were detected for >90% of participants. Participants who reported using hair oil within the past month had MEP concentrations 125% higher (95% confidence interval [CI]: -0.1, 408) than non-users. For other personal care products, we observed the greatest percent difference in PCP-associated metabolites for MIBP among hair gel users (39.3%, 95% CI: -6.3, 107) and for MEP among conditioner/crème rinse users (-55.4%, 95% CI: -76.4, -15.6) compared to non-users.

CONCLUSION

Findings suggest that self-reported use of hair oils during late pregnancy may be associated with higher urinary concentrations of MEP. Hair gel use in late pregnancy may also be associated with higher urinary phthalate metabolite concentrations, while conditioner/crème rinse use may be associated with lower levels if MEP.

Development of an observational exposure human biomonitoring study to assess Canadian children’s DEET exposure during protective use

Biomonitoring data of N,N-diethyl-meta-toluamide (DEET) in children is scarce and limited to controlled exposure and surveillance studies. We conducted a 24-hour observational exposure and human biomonitoring study designed to estimate use of and exposure to DEET-based insect repellents by Canadian children in an overnight summer camp setting. Here, we present our study design and methodology. In 2019, children between the ages of 7 and 13 took part in the study (n = 126). Children controlled their use of DEET-based insect repellents, and provided an account of their activities at camp that could impact insect repellent absorption. Children provided a total of 389 urine samples throughout the study day, and reported the time that they applied insect repellent, which allowed us to contextualize urinary DEET and metabolite concentrations with respect to the timing of insect repellent application. DEET (2.3% <Limits of detection (LOD)) and two metabolites, N,N-diethyl-m-(hydroxymethyl)benzamide (DHMB) (0% <LOD) and 3-diethylcarbamoyl benzoic acid (DCBA) (0% <LOD), were measured in urine samples. Three time difference scenarios were established for the data and analysed to account for these complex time-dependent data, which demonstrated the need for DEET biomonitoring to be done in context with the timing of a known DEET exposure or over the course of at least 14 to 24 hours to better capture the excretion curve. To our knowledge, this is the first field-based study of real-world exposure to DEET in children. Our experience and results suggest that this type of real-world observational exposure study with a human biomonitoring component can generate data reflective of actual exposure, but is not without significant logistic, practical, and analytical challenges.

Phthalate metabolites in paired human serum and whole blood

Presence of phthalate metabolites (PMs) in human serum has been well documented. However, the distribution pattern of PMs in different human blood matrixes remains not well known. To investigate this, paired serum and whole blood samples were collected from 145 adults (76 males and 69 females) in Quzhou, China, and analyzed for nine PMs in this study. All PMs had high detection frequencies (> 70%) in human serum and whole blood, except mono benzyl phthalate. Total concentrations of detected PMs in serum and whole blood were 0.70-61 ng/mL (mean 12 ng/mL) and 1.6-33 ng/mL (7.5 ng/mL), respectively. Mono methyl phthalate (MMP), mono (2-ethylhexyl) phthalate, and mono butyl phthalate were consistently the predominant PMs in human serum and whole blood, with the mean concentrations of 3.4 and 2.0 ng/mL, 3.3 and 2.1 ng/mL, and 2.8 and 1.8 ng/mL, respectively. Females had higher mean serum concentrations of PMs, except MBP, than males. Youngest age group (20-30 years) consistently had the lowest mean whole blood levels of all PMs. For the first time, the distribution pattern of PMs in human blood was evaluated based on the calculated partitioning coefficient (K_p) between serum and whole blood. MMP had the highest mean K_p value (1.6; 10th-90th percentile: 1.0-2.2), while mono (2-ethyl-5-oxohexyl) phthalate had the lowest mean K_p value (0.63; 10th-90th percentile: 0.25-1.3). These results help better understand the occurrence of PMs in human blood.

Evaluation of pollutants in perfumes, colognes and health effects on the consumer: a systematic review

Cosmetic products, especially perfumes and colognes, are widely used in various communities. However, the use of these products can have side effects on consumers. This article aims to review the relevant literature published up to August 2020 to determine whether perfumes and colognes can affect people's health. Relevant articles were identified through electronic search. A total of 562 articles were selected and finally 37 related articles were included in the study after the screening process. The results of this systematic study showed that phthalates, aldehydes, parabens and aluminum-based salts are the most important contaminants in aromatic products that cause side effects such as allergies, breast cancer, reproductive disorders, especially in males, skin allergies, nervous system damage and migraine headaches for consumers. The incidence of complications in people using these products depends on parameters such as age, gender, race, amount of substance consumed, duration of use and economic status, and regarding the relationship between diseases such as cancer, respiratory disorders and endocrine with common contaminants in aromatic products, incidence of these diseases is probable in consumers which require further research to prove.

Plasticizers: negative impacts on the thyroid hormone system

This review aims to understand the impacts of plasticizers on the thyroid system of animals and humans. The thyroid gland is one of the earliest endocrine glands that appear during embryogenesis. The thyroid gland synthesizes thyroid hormones (TH), triiodothyronine (T3), and thyroxine (T4) that are important in the regulation of body homeostasis. TH plays critical roles in regulating different physiological functions, including metabolism, cell growth, circadian rhythm, and nervous system development. Alteration in thyroid function can lead to different medical problems. In recent years, thyroid-related medical problems have increased and this could be due to rising environmental pollutants. Plasticizers are one such group of a pollutant that impacts thyroid function. Plasticizers are man-made chemicals used in a wide range of products, such as children's toys, food packaging items, building materials, medical devices, cosmetics, and ink. The increased use of plasticizers has resulted in their detection in the environment, animals, and humans. Studies indicated that plasticizers could alter thyroid function in both animals and humans at different levels. Several studies demonstrated a positive and/or negative correlation between plasticizers and serum T4 and T3 levels. Plasticizers could also change the expression of various TH-related genes and proteins, including thyroid-stimulating hormone (TSH), thyrotropin-releasing hormone (TRH), and transporters. Histological analyses demonstrated thyroid follicular cell hypertrophy and hyperplasia in response to several plasticizers. In conclusion, plasticizers could disrupt TH homeostasis and the mechanisms of toxicity could be diverse.

Association of Urinary Phthalate and Phthalate Replacement Metabolite Concentrations with Serum Lipid Biomarker Levels among Pregnant Women Attending a Fertility Center

We examined whether urinary concentrations of phthalate and phthalate replacement metabolites were associated with lipid biomarker levels among pregnant women. This cross-sectional study included 175 women who enrolled in the Environment and Reproductive Health (EARTH) Study (2005–2017). We used linear regression models to assess the relationship between urinary phthalates and lipid biomarkers [triglycerides, total cholesterol, high density lipoprotein (HDL), non-HDL, and low-density lipoprotein (LDL) cholesterol] levels while adjusting for confounders. Pregnant women in the highest quartile of urinary mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) had, overall, 14% [31 (95% CI = 6.56) mg/dL], 21% [33 (95% CI = 9.57) mg/dL] and 25% [30 (95% CI = 8.53) mg/dL] higher serum total, non-HDL and LDL cholesterol, respectively, compared to women in the lowest quartile of MECPP. Similar positive associations were found for urinary concentrations of other metabolites of di(2-ethylhexyl) phthalate, mono(2-ethylhexyl) phthalate, and mono(2-ethyl-5-oxohexyl) phthalate. Pregnant women with urinary mono-n-butyl phthalate (MBP) in the highest quartile had higher triglycerides and non-HDL cholesterol compared to women with MBP in the lowest quartile. Women with detectable concentrations of two phthalate replacement metabolites had lower HDL cholesterol compared to women with non-detectable concentrations. Gestational urinary concentrations of certain phthalate and phthalate replacement metabolites were associated with lipid levels among these women.

Environmental Exposure to Non-Persistent Endocrine Disrupting Chemicals and Endometriosis: A Systematic Review

Endometriosis is a disease characterized by the presence of the uterine endometrium outside of its normal location. As the etiology of endometriosis is not well known and hormonal imbalance is central to disease pathogenesis, the potential contribution of exposure to endocrine-disrupting chemicals (EDCs) has been hypothesized in endometriosis. A systematic search of the literature was carried out to identify relevant studies using: PubMed, Scopus, Elsevier, Springer; EBSCO, and Web of Science. A total of 22 studies were considered. Most of the studies reviewed in this paper showed an association between exposure to BPA and phthalates and endometriosis. In the case of phthalate exposure, the reviewed studies found an association between the concentration of at least one phthalate metabolite and endometriosis. Only one study was performed to assess the exposure to parabens and a significant relationship with endometriosis was found. Additionally, only one study assessed the relationship of non-persistent pesticide exposure with endometriosis, observing a significant association between endometriosis and the urinary concentration of diazinon, chlorpyrifos, and chlorpyrifos-methyl. Studies struggled to provide a conclusion on the effect of exposure to benzophenones on endometriosis. Despite the numerous limitations of the results, the reviewed studies suggest that exposure to non-persistent endocrine disruptors, especially bisphenol A and phthalates may affect endometriosis. The results of the studies on exposure to parabens, benzophenones, and non-persistent insecticides are inconclusive.

Personal care products: Demographic characteristics and maternal hormones in pregnant women from Puerto Rico

Personal care products (PCPs) refer to a wide variety of items commonly characterized as health or beauty products. PCPs contain a number of ingredients, often including a wide range of endocrine disrupting chemicals such as phthalates and parabens. The present study examines the association between self-reported PCP use and prenatal sex-steroids and thyroid hormones levels in women from Puerto Rico. We recruited pregnant women (n = 1070) through the Puerto Rico PROTECT Cohort and collected blood, demographic and pregnancy-related data at recruitment and subsequent visits. PCP use in the 48-h preceding the blood sample was collected through self-reported questionnaires. Nine hormones (corticotropin-releasing hormone [CRH], sex-hormone binding globulin [SHBG], estriol [E3], progesterone, testosterone, thyroid-stimulating hormone [TSH], total triiodothyronine [T3], total thyroxine [T4], and free thyroxine [fT4]) were measured in maternal serum samples at two points during pregnancy. Linear mixed models with random intercepts were used to examine associations between PCP use and serum hormone levels. Use of cosmetics significantly increased with age, household income and education level (p < 0.01). Use of hair products, such as hair dyes and bleach, relaxers, and mousse, was associated with lower levels of all sex steroid hormones compared to non-use: SHBG (%Δ = -7.1, 95%CI: -12.4,-1.8), E3 (%Δ = -23.2, 95%CI: -32.2,-13.0), progesterone (%Δ = -21.5, 95%CI: -29.4,-12.9) and testosterone (%Δ = -21.5, 95%CI: -33.1,-7.8) adjusted for maternal age, education and pre-pregnancy body mass index. Our findings suggest that household income and education level influence PCP use among pregnant women in this study. Use of certain hair products was associated with lower concentrations of sex steroid hormones. Although there are limitations to questionnaire data, characterizing PCP use is inexpensive and may represent exposure from multiple classes of chemicals, including chemicals that may not specifically appear on product labels and/or have not been tested for endocrine disrupting potential, making it a useful complement to chemical biomarker data.

Prenatal maternal phthalate exposures and trajectories of childhood adiposity from four to twelve years

BACKGROUND/AIM

Adiposity trajectories reflect dynamic process of growth and may predict later life health better than individual measures. Prenatal phthalate exposures may program later childhood adiposity, but findings from studies examining these associations are conflicting. We investigated associations between phthalate biomarker concentrations during pregnancy with child adiposity trajectories.

METHODS

We followed 514 mother-child pairs from the Mexico City PROGRESS cohort from pregnancy through twelve years. We measured concentrations of nine phthalate biomarkers in 2nd and 3rd trimester maternal urine samples to create a pregnancy average using the geometric mean. We measured child BMI z-score, fat mass index (FMI), and waist-to-height ratio (WHtR) at three study visits between four and 12 years of age. We identified adiposity trajectories using multivariate latent class growth modeling, considering BMI z-score, FMI, and WHtR as joint indicators of latent adiposity. We estimated associations of phthalates biomarkers with class membership using multinomial logistic regression. We used quantile g-computation to estimate the potential effect of the total phthalate mixture and assessed effect modification by sex.

RESULTS

We identified three trajectories of child adiposity, a "low-stable", a "low-high", and a "high-high" group. A doubling of the sum of di (2-ethylhexyl) phthalate metabolites (ΣDEHP), was associated with 1.53 (1.08, 2.19) greater odds of being in the "high-high" trajectory in comparison to the "low-stable" group, whereas a doubling in di-isononyl phthalate metabolites (ΣDiNP) was associated with 1.43 (1.02, 2.02) greater odds of being in the "low-high" trajectory and mono (carboxy-isononyl) phthalate (MCNP) was associated with 0.66 (0.45, 97) lower odds of being in the "low-high" trajectory. No sex-specific associations or mixture associations were observed.

CONCLUSIONS

Prenatal concentrations of urinary DEHP metabolites, DiNP metabolites, and MCNP, a di-isodecyl phthalate metabolite, were associated with trajectories of child adiposity. The total phthalate mixture was not associated with early life child adiposity.

Exposure of childbearing-aged female to phthalates through the use of personal care products in China: An assessment of absorption via dermal and its risk characterization

Phthalates (PAEs) are widely used in personal care products (PCPs) and skin care packaging materials. Through national representative sampling, 328 childbearing-aged females in China were investigated by questionnaire, whose contact factors for 30 cosmetic products were collected. According to the daily exposure method and adverse cumulative effects of PAE exposure on female reproduction, we derived the ERα, ERβ binding, and AR anti-androgenic effects. The utilization rates of acne cleanser, acne cream, cleanser (non-acne), and cream (non-acne) in volunteers were 21.90%, 22.22%, 51.63%, and 51.96%, respectively. Examining the data for PAEs in PCPs, the content of DBP (dibutyl phthalate) in them was significantly higher for tubes (0.26 ± 0.05 μg/g) and other packaging (pump type and metal tube) (0.25 ± 0.03 μg/g) than bowl (0.17 ± 0.04 μg/g). The DBP content of acne cream (0.27 ± 0.03 μg/g) was significantly higher than that of non-acne cream (0.17 ± 0.03 μg/g); likewise, there was significantly more DEHP (di (2-ethylhexyl) phthalate) in acne cleanser (0.87 ± 0.15 μg/g) than non-acne cleanser (0.64 ± 0.36 μg/g). Students and office worker were the main consumers of PCPs; however, among all occupation groups, the daily exposure dose of PCPs for workers was highest (mean = 0.0004, 0.0002, 0.0009 μg/kg bw/day for DEP (diethyl phthalate), DBP, and DEHP, respectively). The cumulative indices of PAEs' exposure revealed that the level of ERα and ERβ binding and AR anti-androgenic effects in workers was respectively 0.4935, 0.0186, and 0.2411 μg/kg bw/day. The risk index (HI_TDI and HI_RfDs) of DEP, DBP, and DEHP was lower than their corresponding reference value (hazard index <1), but using PCPs may cause potential health risks. Therefore, we should pay attention to the adverse effects of PAEs on female reproductive functioning, especially the cumulative exposure of females of childbearing age.

The Potential Relationship Between Environmental Endocrine Disruptor Exposure and the Development of Endometriosis and Adenomyosis

Women with endometriosis, the growth of endometrial glands and stroma outside the uterus, commonly also exhibit adenomyosis, the growth of endometrial tissues within the uterine muscle. Each disease is associated with functional alterations in the eutopic endometrium frequently leading to pain, reduced fertility, and an increased risk of adverse pregnancy outcomes. Although the precise etiology of either disease is poorly understood, evidence suggests that the presence of endometriosis may be a contributing factor to the subsequent development of adenomyosis as a consequence of an altered, systemic inflammatory response. Herein, we will discuss the potential role of exposure to environmental toxicants with endocrine disrupting capabilities in the pathogenesis of both endometriosis and adenomyosis. Numerous epidemiology and experimental studies support a role for environmental endocrine disrupting chemicals (EDCs) in the development of endometriosis; however, only a few studies have examined the potential relationship between toxicant exposures and the risk of adenomyosis. Nevertheless, since women with endometriosis are also frequently found to have adenomyosis, discussion of EDC exposure and development of each of these diseases is relevant. We will discuss the potential mechanisms by which EDCs may act to promote the co-development of endometriosis and adenomyosis. Understanding the disease-promoting mechanisms of environmental toxicants related to endometriosis and adenomyosis is paramount to designing more effective treatment(s) and preventative strategies.

Di-n-butyl phthalate disrupts neuron maturation in primary rat embryo neurons and male C57BL/6 mice

Di-n-butyl phthalate (DBP) is commonly used as a plasticizer and its usage continues to increase in conjunction with plastic consumption. DBP is readily released into air, drinking water, and soil, and unfortunately, is a potent endocrine disrupter that impairs central nervous system functions. Previously DBP was found to (1) arrest the cell cycle of C17.2 neural progenitor cells (NPCs) at the G1 phase, (2) reduce numbers of newly generated neural stem cells in the mouse hippocampus, and (3) adversely affect learning and memory. Other investigators also noted DBP-mediated neurotoxic effects, but as yet, no study has addressed the adverse effects of DBP on neuronal differentiation. Data demonstrated that at 200 μM DBP induced apoptosis in rat embryo primary neurons by increasing reactive oxygen species levels and inducing mitochondrial dysfunction. However, no significant effect was detected on neurons at concentrations of ≤100 μM. In contrast, doublecortin/microtubule associated protein-2 (DCX/MAP2) immunocytochemistry showed that DBP at 100 μM delayed neuronal maturation by increasing protein levels of DCX (an immature neuronal marker), without markedly affecting cell viability. Further in vivo studies confirmed that DCX⁺ cell numbers were significantly elevated in the hippocampus of DBP-treated mice, indicating that DBP delayed neuronal maturation, which is known to be associated with impaired memory retention. Data demonstrated that DBP might disrupt neuronal maturation, which is correlated with reduced neurocognitive functions.

The effects of phthalate ester exposure on human health: A review

Phthalate esters (PAEs) are one of the most widely used plasticizers in polymer products and humans are increasingly exposed to them. The constant exposure to PAEs-contained products has raised some concerns against human health. Thus, the impacts of PAEs and their metabolites on human health require a comprehensive study for a better understanding of the associated risks. Here, we attempt to review eight main health effects of PAE exposure according to the most up-to-date studies. We found that epidemiological studies demonstrated a consistent association between PAE exposure (especially DEHP and its metabolites) and a decrease in sperm quality in males and symptom development of ADHD in children. Overall, we found insufficient evidence and lack of consistency of the association between PAE exposure and cardiovascular diseases (hypertension, atherosclerosis, and CHD), thyroid diseases, respiratory diseases, diabetes, obesity, kidney diseases, intelligence performance in children, and other reproductive system-related diseases (anogenital distance, girl precocious puberty, and endometriosis). Future studies (longitudinal and follow-up investigations) need to thoroughly perform in large-scale populations to yield more consistent and powerful results and increase the precision of the association as well as enhance the overall understanding of potential human health risks of PAEs in long-term exposure.

Critical windows of fluoride neurotoxicity in Canadian children

BACKGROUND

Fluoride has been associated with IQ deficits during early brain development, but the period in which children are most sensitive is unknown.

OBJECTIVE

We assessed effects of fluoride on IQ scores across prenatal and postnatal exposure windows.

METHODS

We used repeated exposures from 596 mother-child pairs in the Maternal-Infant Research on Environmental Chemicals pregnancy and birth cohort. Fluoride was measured in urine (mg/L) collected from women during pregnancy and in their children between 1.9 and 4.4 years; urinary fluoride was adjusted for specific gravity. We estimated infant fluoride exposure (mg/day) using water fluoride concentration and duration of formula-feeding over the first year of life. Intelligence was assessed at 3-4 years using the Wechsler Preschool and Primary Scale of Intelligence-III. We used generalized estimating equations to examine the associations between fluoride exposures and IQ, adjusting for covariates. We report results based on standardized exposures given their varying units of measurement.

RESULTS

The association between fluoride and performance IQ (PIQ) significantly differed across prenatal, infancy, and childhood exposure windows collapsing across child sex (p = .001). The strongest association between fluoride and PIQ was during the prenatal window, B = -2.36, 95% CI: -3.63, -1.08; the association was also significant during infancy, B = -2.11, 95% CI: -3.45, -0.76, but weaker in childhood, B = -1.51, 95% CI: -2.90, -0.12. Within sex, the association between fluoride and PIQ significantly differed across the three exposure windows (boys: p = .01; girls: p = .01); among boys, the strongest association was during the prenatal window, B = -3.01, 95% CI: -4.60, -1.42, whereas among girls, the strongest association was during infancy, B = -2.71, 95% CI: -4.59, -0.83. Full-scale IQ estimates were weaker than PIQ estimates for every window. Fluoride was not significantly associated with Verbal IQ across any exposure window.

CONCLUSION

Associations between fluoride exposure and PIQ differed based on timing of exposure. The prenatal window may be critical for boys, whereas infancy may be a critical window for girls.

Correlation study of parabens in urine, serum, and seminal plasma of adult men in Beijing, China

The adverse effects of parabens raise concerns about their extensive use as preservatives in consumer products, especially in cosmetics. Until now, their distribution and excretion in humans have attracted little attention. Here, we quantified various agents including, for the first time, methyl-; ethyl-; n-propyl-; n-butyl-, and i-butylparaben (MeP, EtP, PrP, n-BuP, i-BuP); methyl- and ethyl-protocatechuate (OH-MeP and OH-EtP); hydroxybenzoic acid (4-HB); and 3,4-dihydroxybenzoic acid (3,4-DHB) in urine, serum, and seminal plasma samples from 50 healthy Chinese men in Beijing, China. Urine paraben concentrations were 1-2 orders of magnitudes higher than those in serum and seminal plasma. MeP and PrP were predominant and correlated with each other in the urine, serum, and seminal plasma. In urine, we observed a significant correlation between MeP and OH-MeP; EtP and OH-EtP; and 4-HB and 3,4-DHB concentrations. All these results provide new information on parabens as biomarkers for the assessment of exposure.

Prenatal Exposure to Di-Ethyl Phthalate (DEP) Is Related to Increasing Neonatal IgE Levels and the Altering of the Immune Polarization of Helper-T Cells

Introduction: Phthalates are substances that are added to plastic products to increase their plasticity. These substances are released easily into the environment and can act as endocrine disruptors. Epidemiological studies in children have showed inconsistent findings regarding the relationship between prenatal or postnatal exposure to phthalates and the risk of allergic disease. Our hypothesis is that prenatal exposure to phthalates may contribute to the development of allergies in children. Material and methods: The objective of this study was to determine the associations between urinary phthalate metabolite concentrations in pregnant women, maternal atopic diathesis, maternal lifestyle, and cord blood IgE. Pregnant mothers and paired newborns (n = 101) were enrolled from an antenatal clinic. The epidemiologic data and the clinical information were collected using standard questionnaires and medical records. The maternal blood and urine samples were collected at 24–28 weeks gestation, and cord blood IgE, IL-12p70, IL-4, and IL-10 levels were determined from the newborns at birth. The link between phthalates and maternal IgE was also assessed. To investigate the effects of phthalates on neonatal immunity, cord blood mononuclear cells (MNCs) were used for cytokine induction in another in vitro experiment. Results: We found that maternal urine monoethyl phthalate (MEP) (a metabolite of di-ethyl phthalate (DEP)) concentrations are positively correlated with the cord blood IgE of the corresponding newborns. The cord blood IL-12p70 levels of mothers with higher maternal urine MEP groups (high DEP exposure) were lower than mothers with low DEP exposure. In vitro experiments demonstrated that DEP could enhance IL-4 production of cord blood MNCs rather than adult MNCs. Conclusion: Prenatal DEP exposure is related to neonatal IgE level and alternation of cytokines relevant to Th1/Th2 polarization. This suggests the existence of a link between prenatal exposure to specific plasticizers and the future development of allergies.

Associations of prenatal exposure to vanadium with early-childhood growth: A prospective prenatal cohort study

Prenatal vanadium exposure is reported to be associated with restricted fetal growth and adverse birth outcomes. However, trimester-specific vanadium exposure in relation to early-childhood growth still remains unclear. A total of 1873 Chinese mother-infant pairs from whom a complete series of maternal urinary samples were collected over three stages of pregnancy were included from 2014 to 2016. The urinary concentrations of vanadium were analyzed. Children's anthropometric parameters were measured at birth, 6, 12 and 24 months. In boys, each doubling increase in vanadium concentrations at middle pregnancy was inversely associated with weight-for-length [- 9.07% (-17.21%, -0.93%)] and BMI z-score [- 9.66% (-18.05%, -1.28%)] at 24 months. Moreover, vanadium exposure at late pregnancy was negatively associated with weight [- 9.85% (-16.42%, -3.28%)], weight-for-length [- 11.00% (-18.40%, -3.60%)], and BMI z-scores [- 11.05% (-18.67%, -3.42%)] at 24 months in boys. However, the negative associations were not observed in girls, and we found evidence for sex difference (FDR p for interaction=0.01, 0.01 and 0.03 for weight, weight-for-length and BMI z-scores, respectively). Prenatal vanadium exposure may have an adverse effect on early-childhood growth, and the middle and late pregnancy could be windows of vulnerability for the adverse effects of vanadium exposure on growth development.

Effect of dermal phthalate levels on lung function tests in residential area near a petrochemical complex

Phthalates can leach into indoor and outdoor airborne particulate matter and dust, which can then be ingested or absorbed and induce lung injury. Dermal phthalate levels can be used as a matrix for exposure direct absorption from air, particle deposition, and contact with contaminated products. However, the association between dermal phthalate levels in skin wipes and lung function tests remains unknown. A total of 397 participants were included. Spirometry measurements of forced expiratory volume in 1 s (FEV1, L) and forced vital capacity (FVC, L) were calculated. Dermal phthalate levels of diethyl phthalate (DMP), diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), butyl benzyl phthalate (BBzP), di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DiNP), and diisodecyl phthalate (DiDP) on forehead skin wipes were detected. The one-unit increases in logarithm (log) dermal DnBP (β = - 0.08; 95% CI - 0.16, - 0.003, p = 0.041), BBzP (β = - 0.09; 95% CI - 0.16, - 0.02, p = 0.009), DEHP (β = - 0.07; 95% CI - 0.14, - 0.003, p = 0.042), and DiNP (β = - 0.08; 95% CI - 0.15, - 0.02, p = 0.017) were significantly associated with decreases in FVC. For elderly participants, one-unit increases in log dermal DnBP (β = - 0.25; 95% CI - 0.46, - 0.04, p = 0.021), BBzP (β = - 0.17; 95% CI - 0.33, - 0.01, p = 0.042), and DiDP (β = - 0.19; 95% CI - 0.39, < 0.01, p = 0.052) were associated with decreases in FEV1. In conclusion, dermal phthalate levels were significantly associated with decreases in lung function tests.

Phthalate exposure in association with the use of personal care products among general population from Shanghai

Phthalates are used in a wide variety of personal care products (PCPs) as solubilizer, denaturant or color fixative. However, there are few studies referring the correlation between phthalate exposure and PCPs use among general population in China. In this study, ten metabolites of phthalates in spot urine samples (N = 500) were quantified using ultra-performance liquid chromatography tandem mass spectrometry. The frequency and duration of 12 types of PCPs were collected by questionnaire survey. The associations of phthalate metabolites and PCPs use were assessed by multivariable liner regression models. Median concentration of mono-benzylphthalate (MBzP) was significantly higher among frequent users of almost all PCPs. Low molecular weight phthalates (monomethyl phthalate (MMP), mono-n-butylphthalate (MnBP) and monoisobutylphthalate (MiBP)) were significantly lower among frequent user of some rinse-off PCPs (e.g., shampoo, facial cleanser, and body wash). Meanwhile, monoethylphthalate (MEP) was positive correlated with frequently use of facial moisturizer. Mono-2-ethylhexylphthalate (MEHP) and MBzP showed a significant positive association with frequently use of body lotion. Univariate linear analyses indicated a significant decreasing trend between urinary concentrations of MMP, MnBP, and the number of rinse-off PCPs being frequently used, and a significant increasing trend between urinary MBzP and the number of leave-on products being frequently used. These findings indicated that the use of some PCPs, especially leave-on PCPs, could be a potential source of exposure to some phthalates.