Bisphenol A and other phenols in urine from Danish children and adolescents analyzed by isotope diluted TurboFlow-LC–MS/MS

New approach for the determination of ortho-phenylphenol exposure by measurement of sulfate and glucuronide conjugates in urine using liquid chromatography-tandem mass spectrometry

Ortho-phenylphenol (OPP) has been widely used as a fungicide and preservative. Although low-dose studies have demonstrated its low toxicity in animals and humans, high-dose exposure to this contaminant has toxic effects that range from skin irritation to bladder cancer. Thus far, monitoring of OPP exposure in the general population has been performed by measuring OPP after urine hydrolysis with the β-glucuronidase/arylsulfatase enzyme and sometimes by the use of a mineral acid. We developed a sensitive, accurate, and robust method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to specifically measure two-phase II OPP metabolites excreted in human urine, OPP sulfate (OPP-S), and OPP glucuronide (OPP-G). Comparative analysis of urine samples from 50 volunteers living in the Quebec City area using a direct method and phosphoric acid hydrolysis method previously developed in our laboratory showed no statistically significant difference (p value for paired t test = 0.701) in OPP concentrations. Moreover, a significant difference showed that underestimation (p value for paired t test = 0.025) occurs when β-glucuronidase/arylsulfatase enzyme deconjugation is used. The LOD achieved by the direct method permits the detection of OPP-S and OPP-G metabolites in urine at the submicrogram per liter level. Graphical abstract ᅟ.

Prenatal exposure to benzophenone-3 (BP-3) induces apoptosis, disrupts estrogen receptor expression and alters the epigenetic status of mouse neurons

Current evidence indicates that benzophenone-3 (BP-3) can pass through the placental and blood-brain barriers and thus can likely affect infant neurodevelopment. Despite widespread exposure, data showing the effects of BP-3 on the developing nervous system are scarce. This study revealed for the first time that prenatal exposure to BP-3 led to apoptosis and neurotoxicity, altered the levels of estrogen receptors (ERs) and changed the epigenetic status of mouse neurons. In the present study, subcutaneous injections of pregnant mice with BP-3 at 50 mg/kg, which is an environmentally relevant dose, evoked activation of caspase-3 and lactate dehydrogenase (LDH) release as well as substantial loss of mitochondrial membrane potential in neocortical cells of their embryonic offspring. Apoptosis-focused microarray analysis of neocortical cells revealed up-regulation of 22 genes involved in apoptotic cell death. This effect was supported by increased BAX and CASP3 mRNA and protein levels, as evidenced by qPCR, ELISAs and western blots. BP-3-induced apoptosis and neurotoxicity were accompanied by decreases in the mRNA and protein expression levels of ESR1 and ESR2 (also known as ERα and ERβ), with a simultaneous increase in GPER1 (also known as GPR30) expression. In addition to the demonstration that treatment of pregnant mice with BP-3 induced apoptosis, caused neurotoxicity and altered ERs expression levels in neocortical cells of their embryonic offspring, we showed that prenatal administration of BP-3 inhibited global DNA methylation as well as reduced DNMTs activity. BP-3 also caused specific hypomethylation of the genes Gper1 and Bax, an effect that was accompanied by increased mRNA and protein expression levels. In addition, BP-3 caused hypermethylation of the genes Esr1, Esr2 and Bcl2, which could explain the reduced mRNA and protein levels of the estrogen receptors. This study demonstrated for the first time that prenatal exposure to BP-3 caused severe neuronal apoptosis that was accompanied by impaired ESR1/ESR2 expression, enhanced GPER1 expression, global DNA hypomethylation and altered methylation statuses of apoptosis-related and ERs genes. We suggest that the effects of BP-3 in embryonic neurons may be the fetal basis of the adult onset of nervous system disease.

Biomonitoring of bisphenol A, triclosan and perfluorooctanoic acid in hair samples of children and adults

Bisphenol A (BPA), triclosan (TCS) and perfluorooctanoic acid (PFOA) are endocrine disruptors linked with negative health effects such as developmental, reproductive and cardiovascular toxicity. The aim of this study was to determine simultaneously the concentration of BPA, TCS and PFOA in hair from children and adults and examine possible associations between biomonitoring data and age, gender, dietary habits and body mass index. Methanolic extraction was applied and the compounds were determined by liquid chromatography-mass spectrometry. Low levels of exposure to PFOA were detected for children and adults at concentrations below limit of quantification. The mean concentration of BPA in children and adults was 20.6 and 16.6 pg mg^-1 , while for TCS 275.2 and 687.0 pg mg^-1 , respectively. Children were highly exposed to BPA relative to adults (P = .011) although adults had greater exposure to TCS (P = .003). Hair from girls had a greater burden of BPA (P = .06) compared to boys. Moreover, higher TCS levels were depicted for females in both examined groups (children P = .200 and adults P = .213) compared to males, but no statistical differences were observed. Significant differences were also observed between age groups (P = .0007) for TCS. No correlations were found between BPA or TCS levels and body mass index or dietary habits for both children and adults. Children have a greater exposure to BPA compared to adults, whereas exposure of adults to TCS seems to be higher than that in children and elderly people. Exposure to BPA occurs mainly via ingestion whereas exposure to TCS mainly via dermal absorption.

Impact of enzymatic hydrolysis on the quantification of total urinary concentrations of chemical biomarkers

Human exposure to consumer and personal care products chemicals such as phenols, including parabens and other antimicrobial agents, can be assessed through biomonitoring by quantifying urinary concentrations of the parent chemical or its metabolites, often after hydrolysis of phase II conjugates. Developing suitable analytical methods for the concurrent quantification of multiple exposure biomarkers is challenging because optimal conditions for the hydrolysis of such conjugates (e.g., O-glucuronides, N-glucuronides, sulfates) may differ depending on the biomarker. We evaluated the effectiveness of seven commercial hydrolytic enzymes to simultaneously hydrolyze N-glucuronides (using the antibacterial triclocarban as example compound) and other conjugates (using select phenols and parabens as examples) by using on-line solid phase extraction-high performance liquid chromatography-isotope dilution-tandem mass spectrometry. Incubation (30 min, 55 °C) with a genetically engineered β-glucuronidase (IMCS, ≥15 units/μL urine) hydrolyzed N-glucuronide triclocarban, but did not fully hydrolyze the conjugates of phenols and parabens. By contrast, incubation (4 h, 37 °C) with solid β-glucuronidase (Helix pomatia, Type H-1, ≥30 units/μL urine) or liquid β-glucuronidase/arylsulfatase (Helix pomatia, 30 units/μL urine [i.e., 30 μL/100 μL urine]) in the presence of 100 μL methanol for 100 μL urine completely hydrolyzed N-glucuronide triclocarban and the conjugates of several phenols and parabens, without cleaving the ester bond of the parabens to form p-hydroxybenzoic acid. These results highlight the relevance of method validation procedures that include optimizing the hydrolysis of phase II urinary conjugates (e.g., enzyme type and amount used, reaction time, temperature) to quantify accurately and concurrently multiple exposure biomarkers for biomonitoring purposes.

Relationship between bisphenol A exposure and attention-deficit/ hyperactivity disorder: A case-control study for primary school children in Guangzhou, China

Bisphenol A (BPA) is an endocrine-disrupting chemical. Studies have shown that the exposure to BPA is associated with attention-deficit/hyperactivity disorder (ADHD) during adolescent development. However the direct clinical evidence is limited. To investigate the possible association between environmental BPA exposure and the altered behavior of children, a case-control study was conducted with children aged 6-12 years in Guangzhou, China. Two hundred fifteen children diagnosed with ADHD and 253 healthy children from Guangzhou were recruited as the case and control groups, respectively. Urinary BPA and 8-hydroxy-2'-deoxyguanosine (8-OHdG, a biomarker of oxidative DNA damage) concentrations were determined by high-performance liquid chromatography/tandem spectrometry. The results showed that concentrations of urinary BPA for the case group were significantly higher than those for the control group (3.44 vs 1.70 μg/L; 4.63 vs 1.71 μg/g Crt. p < .001). A stepwise increase in the odds ratios for ADHD was observed with the increasing quartiles of children's urinary BPA (first quartile: reference category; second quartile adjusted OR: 1.79, 95% CI: 0.95-3.37; third quartile adjusted OR: 7.44, 95% CI: 3.91-14.1; fourth quartile adjusted OR: 9.41, 95% CI: 4.91-18.1). When the BPA levels were stratified by gender, the odds of ADHD among boys and girls increased significantly with urinary BPA concentrations (adjusted OR: 4.58, 95% CI: 2.84-7.37; adjusted OR: 2.83, 95% CI: 1.17-6.84). Urinary 8-OHdG concentrations in the ADHD children were significantly higher than those in the control group. Furthermore, the linear regression analysis results indicated that a significant relationship existed between BPA exposure and 8-OHdG levels (R = 0.257, p < .001). Our findings provide direct evidence that childhood BPA exposure may be related to ADHD and 8-OHdG concentrations for children. Moreover, BPA exposure could increase the higher occurrence of ADHD for boy than for girls.

Association of urinary concentrations of four chlorophenol pesticides with cardiometabolic risk factors and obesity in children and adolescents

This study was undertaken to determine the association of four chlorophenol pesticides with cardiometabolic risk factors and obesity in children and adolescents. This cross-sectional study was conducted in 2016 on 242 children and adolescents, aged 6 to 18 years. The concentrations of 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP), 2,4,5-trichlorophenol (2,4,5-TCP), and 2,4,6-trichlorophenol (2,4,6-TCP) in the urine were examined and their association with indices of obesity and cardiometabolic risk factors was determined. Multivariate linear regression and multinomial logistic regression analyses were applied. Overall, 242 participants with mean (SD) ages of 11.3 (2.5) years completed the survey. After adjustment for confounders, a significant positive association was found between body mass index (BMI) z-score and waist circumference (WC) with 2,5-DCP (0.07 (95% CI 0.04, 0.1)) and 0.79 (95% CI 0.54, 1.03), respectively. A significant association of 2,4,5-TCP was only found with WC (0.23 (95% CI 0.0, 0.46), but the relationship with 2,4-DCP was not significant. 2,5-DCP had a significant relationship only with obesity (1.09 (95% CI 1.1, 1.19)), while 2,4-DCP and 2,4,5-TCP showed no significant correlation with overweight or obesity. 2,4-DCP showed a significant positive relationship with high density lipoprotein-cholesterol (HDL-C). Moreover, 2,5-DCP showed a significant negative relationship only with systolic blood pressure and 2,4,5-TCP had a statistically significant inverse association with total cholesterol and HDL-C (-0.71 (95% CI -0.98, -0.45)). This study suggests potential associations of chlorophenol pesticides with overweight, obesity, lipid profile, and blood pressure in children and adolescents. Longitudinal studies are necessary to assess the clinical impact of these findings.

Biomonitoring of chlorophenols in human urine from several Asian countries, Greece and the United States

Chlorophenols (CPs) are used in the production of pesticides and preservatives. Although human exposure to CPs has been known for years, current exposure levels to these chemicals in Asian countries are not known. In this study, we analyzed concentrations of eight CPs in 300 human urine samples collected from nine countries. Of these CPs, 2,5-dichlorophenol and 2,4-dichlorophenol were found at the highest median concentrations (median for all nine countries: 1.78 and 0.34 ng/mL, respectively). Pentachlorophenol was found in 59% of the samples analyzed at a median concentration of 0.07 ng/mL. Urine samples from Japan had the highest concentration of total CPs (median: 16.7 ng/mL) with 2,5-dichlorophenol accounting for 93.1% of the total concentration. The estimated daily intake (DI) for precursors of dichlorophenols varied widely, but several samples showed values higher than the acceptable DI recommended by the United States Environmental Protection Agency (EPA). These results suggest that CP exposure, especially to dichlorophenols, is prevalent in several countries, particularly in Asia, suggesting a pressing need for further assessment of the global sources and potential health effects of these chemicals.

Serum Phthalate and Triclosan Levels Have Opposing Associations With Risk Factors for Gestational Diabetes Mellitus

Certain phthalates and bisphenol A (BPA) have been associated with insulin resistance and type 2 diabetes in non-pregnant adults, but studies of gestational diabetes mellitus (GDM) have reported conflicting results for phthalates and no associations with BPA. Our aim was to investigate the relationship between maternal serum levels of phthalate metabolites and phenols at 10-17 weeks of gestation and glucose homeostasis at 28 weeks of gestation. 232 women aged ≥16 years without type 1 or 2 diabetes with singleton male pregnancies were recruited from a single UK maternity centre between 2001 and 2009 as part of a prospective observational study (Cambridge Baby Growth Study). Serum levels of 16 phthalate metabolites and 9 phenols (including BPA) were measured using liquid chromatography/tandem mass spectrometry. Oral glucose tolerance tests were performed at 28 weeks. 47/232 (20.3%) women had GDM. First-trimester triclosan (TCS) was inversely associated with incident GDM (adjusted odds ratio per log increase in concentration 0.54, 95% confidence interval 0.34-0.86, p = 0.010). Amongst women without GDM, first-trimester mono-(2-ethylhexyl) phthalate and mono(carboxyisooctyl) phthalate levels were positively associated with 120-min plasma glucose (adjusted β 0.268 and 0.183, p = 0.0002 and 0.010, respectively) in mid-pregnancy. No other monotonic associations were detected between phthalate or phenol levels and fasting or stimulated plasma glucose, β-cell function, insulin resistance, or 60-min disposition index. Our results support a glycaemia-raising effect of phthalates during pregnancy, consistent with findings in non-pregnant populations and suggest a possible protective effect of exposure to TCS against GDM.

Bisphenol A, phthalate metabolites and glucose homeostasis in healthy normal-weight children

INTRODUCTION

Bisphenol A and several of the most commonly used phthalates have been associated with adverse metabolic health effects such as obesity and diabetes. Therefore, we analyzed these man-made chemicals in first morning urine samples from 107 healthy normal-weight Danish children and adolescents.

METHOD

This was a cross-sectional study. Participants were recruited as part of the Copenhagen Puberty Study. The subjects were evaluated by an oral glucose tolerance test (OGTT), a dual-energy X-ray absorptiometry (DXA) scan, direct oxygen uptake measurement during cycle ergometry and fasting blood samples. First morning urine was collected and phthalate metabolites and BPA were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with prior enzymatic deconjugation. Individual chemical concentrations were divided into tertiles and analyzed in relation to biological outcome.

RESULTS

Children in the lowest tertile of urinary BPA had significantly higher peak insulin levels during OGTT (P = 0.01), lower insulin sensitivity index (P < 0.01), higher leptin (P = 0.03), triglyceride (P < 0.01) and total cholesterol levels (P = 0.04), lower aerobic fitness (P = 0.02) and a tendency toward higher fat mass index (P = 0.1) compared with children in the highest tertile for uBPA. No significant differences in anthropometrics, body composition or glucose metabolism were associated with any of the phthalate metabolites measured.

CONCLUSION

This pilot study on healthy normal-weight children suggests an inverse association between BPA and insulin resistance. Our findings contrast other cross-sectional studies showing a positive association for BPA, which may be due to confounding or reverse causation because diet is an important source of both BPA exposure and obesity.

Occurrence of and human exposure to parabens, benzophenones, benzotriazoles, triclosan and triclocarban in outdoor swimming pool water in Changsha, China

The entry of personal care products (PCPs) into the environment has, in turn, caused negative influences to human health. Public swimming pools are places that have attracted increasing concerns. In this article, 35 outdoor swimming pools in Changsha City (China) were examined in view of the occurrence of 22 target PCPs contaminants, which fall into four categories: preservatives, UV filters, anticorrosion agents, and antimicrobials. Out of them, 16 compounds were detected in the collected samples. The preservatives was the most dominant category, with methyl paraben being the top compound (a.v. 0.85μg/L) followed by p-hydroxybenzoic acid (a.v. 0.13μg/L) and 1H-benzotriazole (a.v. 0.14μg/L). The correlations among 22 PCPs and their four categories were evaluated using the nonparametric Spearman correlations analysis. In the source tracing investigation, the level of PCPs in swimming pools was determined to be primarily associated with the consumption of these products while weakly related to the filling waters. The quantitative risk assessment revealed that the PCPs concentrations were at a safe level.

Urinary Concentrations of Triclosan, Benzophenone-3, and Bisphenol A in Taiwanese Children and Adolescents

The purpose of this study was to determine the levels of urinary triclosan (TCS), benzophenone-3 (BP-3), and bisphenol A (BPA) in 52 children and 71 adolescents. The effects of age and sex on the levels of urinary TCS, BP-3, and BPA were explored, respectively. Results demonstrated the overall detection rates of urinary TCS, BP-3, and BPA were 18.7%, 8.1%, and 49.6%, respectively. The females had higher TCS concentrations than males (p = 0.051). The detection rate of urinary BP-3 in females (12.3%) was higher than that in males (0%) (p = 0.015). Moreover, the detection rate of urinary BP-3 in adolescents (14.1%) was higher than that in children (0%) (p = 0.005). For children, no urinary BP-3 was found. There were no differences in detection rates and concentrations of urinary TCS, BP-3, and BPA between males and females, respectively. For adolescents, urinary BP-3 was only found in the females. Urinary TCS levels in females were higher than those in males (p = 0.047). The present study showed that urinary TCS concentrations in females were significantly higher than those in males, respectively. In addition, BP-3 was only detected in urine samples of female adolescents. Sex and age were the important factors influencing urinary TCS and BP-3 concentrations.

Carcinogenic risk and Bisphenol A exposure: A focus on molecular aspects in endoderm derived glands

Epidemiological and experimental evidence associates the exposure to Bisphenol A with the increase of cancer risk in several organs, including prostate. BPA targets different pathways involved in carcinogenicity including the Nuclear Receptors (i.e. estrogen and androgen receptors), stress regulated proteins and, finally, epigenetic changes. Here, we analyse BPA-dependent carcinogenesis in endoderm-derived glands, thyroid, liver, pancreas and prostate focusing on cell signalling, DNA damage repair pathways and epigenetic modifications. Mainly, we gather molecular data evidencing harmful effects at doses relevant for human risk (low-doses). Since few molecular data are available, above all for the pancreas, we analysed transcriptomic data generated in our laboratory to suggest possible mechanisms of BPA carcinogenicity in endoderm-derived glands, discussing the role of nuclear receptors and stress/NF-kB pathways. We evidence that an in vitro toxicogenomic approach might suggest mechanisms of toxicity applicable to cells having the same developmental origin. Although we cannot draw firm conclusions, published data summarized in this review suggest that exposure to BPA, primarily during the developmental stages, represents a risk for carcinogenesis of endoderm-derived glands.

Exposure assessment to bisphenol A (BPA) in Portuguese children by human biomonitoring

Exposure to bisphenol A (BPA) is known to be widespread and available data suggests that BPA can act as an endocrine disruptor. Diet is generally regarded as the dominant BPA exposure source, namely through leaching to food from packaging materials. The aim of this study was to evaluate the exposure of 110 Portuguese children (4-18 years old), divided in two groups: the regular diet group (n = 43) comprised healthy normal weight/underweight children with no dietary control; the healthy diet group (n = 67) comprised children diagnosed for obesity/overweight (without other known associated diseases) that were set on a healthy diet for weight control. First morning urine samples were collected and total urinary BPA was analyzed after enzymatic hydrolysis via on-line HPLC-MS/MS with isotope dilution quantification. Virtually, all the children were exposed to BPA, with 91% of the samples above the LOQ (limit of quantification) of 0.1 μg/L. The median (95th percentile) urinary BPA levels for non-normalized and creatinine-corrected values were 1.89 μg/L (16.0) and 1.92 μg/g creatinine (14.4), respectively. BPA levels in the regular diet group were higher than in the healthy diet group, but differences were not significant. Calculated daily BPA intakes, however, were significantly higher in children of the regular diet group than in children of healthy diet group. Median (95th percentile) daily intakes amounted to 41.6 (467) ng/kg body weight/day in the regular diet group, and 23.2 (197) ng/kg body weight/day in the healthy diet group. Multiple logistic regression analysis revealed that children in the healthy diet group had 33% lower intakes than children in the regular diet group (OR 0.67; 95% CI 0.51-0.89). For both groups, however, urinary BPA levels and daily BPA intakes were within the range reported for other children's populations and were well below health guidance values such as the European Food Safety Authority (EFSA) temporary tolerable daily intake (t-TDI) of 4 μg/kg body weight/day. In addition, lower daily BPA intakes were more likely linked with the inherent dietary approach rather than with high BMI or obesity.

Biomonitoring of Danish school children and mothers including biomarkers of PBDE and glyphosate

BACKGROUND

The Danish part of the large European Human biomonitoring pilot project Demonstration of a study to Coordinate and Perform Human biomonitoring on a European Scale (DEMOCOPHES) investigated the urine, hair and blood concentrations of 66 different environmental chemicals in a group of 145 Danish school children aged 6-11 years and their mothers from rural and urban areas in autumn 2011. Some - but not all - results were published; however, the concurrence of the chemicals has not been assessed.

METHODS

The measured concentrations of polybrominated diphenyl ethers (PBDEs) and glyphosate is assessed to complete the investigation of all 66 chemicals in DEMOCOPHES. The concentrations of PBDEs were measured in plasma samples of 143 mothers and 116 children. Glyphosate was measured in a subsample of 27 urine samples. Previously assessed chemicals were polychlorinated biphenyls (PCBs), and polyfluoroalkyl substances (PFASs) analyzed in blood samples, mercury analyzed in hair, and phthalate metabolites, parabens, phenols, cadmium, paracetamol and cotinine analyzed in urine samples. Differences in concentrations between mothers and children were assessed, and the associations between the concentrations of the different environmental chemicals. investigated by correlation analysis.

RESULTS

PBDE47 was found in relatively high levels compared with previous Danish results in both mothers and children, with a significantly higher level in the children compared to their mothers. Glyphosate in concentrations around 1 ng/mL was detected in all 27 samples. The analyzed environmental exposures seem to follow a pattern where chemicals within the same classes are strongly correlated and where children and mothers are exposed to the same chemicals.

CONCLUSION

The correlations between the measured environmental chemicals indicate that a specific exposure pattern may exist, where people who are highly exposed to one class of environmental chemicals also may be highly exposed to certain other classes. As some of the compounds were measured in higher levels in children compared to mothers, increased focus also on the exposure in young children is recommended. For more detailed investigation of specific exposure sources more studies with increased power and detailed questionnaires should be developed.

The Effect of Bisphenol A on Puberty: A Critical Review of the Medical Literature

Many scientific studies have revealed a trend towards an earlier onset of puberty and have disclosed an increasing number of children that display precocious puberty. As an explanation, some authors have considered the global socio-economic improvement across different populations, and other authors have considered the action of endocrine disrupting chemicals (EDCs). Among these, bisphenol A (BPA), an aromatic compound largely used worldwide as a precursor of some plastics and chemical additives, is well known for its molecular oestrogen-like and obesogenic actions. We reviewed the medical literature of the previous 20 years that examined associations between BPA exposure and the age of puberty in humans, considering only those referring to clinical or epidemiological data. Of 19 studies, only 7 showed a correlation between BPA and puberty. In particular, the possible disruptive role of BPA on puberty may be seen in those with central precocious puberty or isolated premature breast development aged 2 months to 4 years old, even if the mechanism is undefined. Some studies also found a close relationship between urinary BPA, body weight, and early puberty, which can be explained by the obesogenic effect of BPA itself. The currently available data do not allow establishment of a clear role for BPA in pubertal development because of the conflicting results among all clinical and epidemiological studies examined. Further research is needed to fully understand the potential role of exposure to EDCs and their adverse endocrine health outcomes.

Exposure to phenols, parabens and UV filters: Associations with loss-of-function mutations in the filaggrin gene in men from the general population

BACKGROUND

Filaggrin is an epidermal protein that is important for normal skin barrier functions. Up to 10% of Europeans and Asians carry filaggrin gene (FLG) loss-of function mutations that appear to facilitate trans-epidermal penetration of certain chemicals. We previously showed that mutation carriers have higher internal exposure to certain phthalates, compared to controls, and hypothesized that they could have increased trans-epidermal penetration of other chemicals.

OBJECTIVES

We investigated exposure to non-persistent chemicals in young Danish men with and without FLG mutations.

METHODS

Concentrations of eight simple phenols, six parabens and nine UV filters were analysed in urine from 65 FLG loss-of-function mutation carriers and 130 non-carriers (controls). Regression analyses, controlling for urinary dilution and confounders, were performed to estimate associations between FLG mutation status and chemical concentrations in urine.

RESULTS

FLG mutation carriers had 80% (13-180%) higher urinary concentrations of methyl paraben (MeP) and 91% (13-219%) higher concentrations of n-propyl paraben (n-PrP) than controls. For 13 compounds, levels were higher in FLG mutation carriers, although differences were only statistically significant for MeP and n-PrP. Combined statistical analysis of concentrations of all the 18 compounds that were detectable in >10% of subjects, suggested that concentrations were generally higher in mutation carriers (p=0.03).

CONCLUSION

FLG loss-of-function mutation carriers have a higher internal exposure to some non-persistent chemicals, independently of atopic dermatitis. This may be due to increased trans-epidermal absorption and/or higher exposure, and mutation carriers may constitute a group susceptible to increased absorption of chemicals and topical medication.

Higher urinary bisphenol A concentration and excessive iodine intake are associated with nodular goiter and papillary thyroid carcinoma

In the present study, we investigated whether bisphenol A (BPA) levels and excessive iodine intake were associated with papillary thyroid carcinoma (PTC) and nodular goiter (NG). We determined total BPA concentrations (TBC) in paired serum and urine samples, and urinary iodine concentrations (UIC) in urine samples collected from PTC patients, NG patients, and healthy individuals, then compared BPA concentrations and UIC within and between each patient group. The results showed that there were no gender-specific differences in serum TBC and UIC in each group, and no differences across all patient groups. Urinary BPA concentrations (UBC) were higher in the NG and PTC groups compared with the control group. UBC showed gender-specific differences in the NG and PTC group. Furthermore, UIC were higher in the NG and PTC groups compared with the control group. Higher UBC and excessive iodine intake were risk factors for NG and PTC according to multivariate logistic regression analysis. There was a significant correlation between UBC and UIC in each group. These data suggested that higher UBC and excessive iodine intake are associated with NG and PTC. The metabolic and functional pathways between BPA and iodine are potentially linked to the pathogenesis and progression of NG and PTC.

Assumed non-persistent environmental chemicals in human adipose tissue; matrix stability and correlation with levels measured in urine and serum

The aim of this study was to (1) optimize a method for the measurement of parabens and phenols in adipose tissue, (2) evaluate the stability of chemical residues in adipose tissue samples, and (3) study correlations of these compounds in urine, serum, and adipose tissue. Samples were obtained from adults undergoing trauma surgery. Nine phenols and seven parabens were determined by isotope diluted TurboFlow-LC-MS/MS. The analytical method showed good accuracy and precision. Limits of detection (LOD) for parabens and phenols ranged from 0.05 to 1.83ng/g tissue. Good recovery rates were found, even when biological samples remained defrosted up to 24h. Benzophenone-3 (BP-3; range of values: <LOD-1.48ng/g tissue) and methylparaben (MeP; <LOD-1.78ng/g tissue) were detected in >70% of adipose tissue samples, while bisphenol-A (BPA; <LOD-3.28ng/g tissue) and 2-phenylphenol (2-PP; <LOD-0.78ng/g tissue) were detected in >40% of adipose tissue samples. In general, levels were similar between adipose tissue and serum, while a correlation between adipose tissue and urine was only found for BP-3. In conclusion, adipose tissue samples in this study were found to contain environmental chemicals considered to be non-persistent, whose levels were weakly or not at all correlated with the urine burden. Therefore, adipose tissue may potentially provide additional information to that obtained from other biological matrices. Further investigations are warranted to explore whether adipose tissue might be a suitable matrix for assessment of the consequences for human health of mid/long-term exposure to these chemicals.

Environmental influences on ovarian dysgenesis - developmental windows sensitive to chemical exposures

A woman's reproductive health and ability to have children directly affect numerous aspects of her life, from personal well-being and socioeconomic standing, to morbidity and lifespan. In turn, reproductive health depends on the development of correctly functioning ovaries, a process that starts early during fetal life. Early disruption to ovarian programming can have long-lasting consequences, potentially manifesting as disease much later in adulthood. A growing body of evidence suggests that exposure to chemicals early in life, including endocrine-disrupting chemicals, can cause a range of disorders later in life, such as those described in the ovarian dysgenesis syndrome hypothesis. In this Review, we discuss four specific time windows during which the ovary is particularly sensitive to disruption by exogenous insults: gonadal sex determination, meiotic division, follicle assembly and the first wave of follicle recruitment. To date, most evidence points towards the germ cell lineage being the most vulnerable to chemical exposure, particularly meiotic division and follicle assembly. Environmental chemicals and pharmaceuticals, such as bisphenols or mild analgesics (including paracetamol), can also affect the somatic cell lineages. This Review summarizes our current knowledge pertaining to environmental chemicals and pharmaceuticals, and their potential contributions to the development of ovarian dysgenesis syndrome. We also highlight knowledge gaps that need addressing to safeguard female reproductive health.

Exposure to UV filters during summer and winter in Danish kindergarten children

BACKGROUND

Ultra violet (UV) filters with known or suspected endocrine disrupting properties are widely used in sunscreens and other personal care products, clothing, food packaging and many other consumer products. Danish kindergarten children have sunscreens applied daily during summer to prevent skin burns.

OBJECTIVES

To estimate the assumed contribution of sunscreens to the total exposure to UV filters, we measured the urinary excretion of UV filters during summer and winter in kindergarten children.

METHODS

Spot- and first morning urines were collected during a summer and a winter day in 2013. A total of 266 urine samples were collected from 55 children and were analysed for content of benzophenone (BP), benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), 5-chloro-2-hydroxybenzophenone (BP-7), 4-methyl-benzophenone (4-MBP), 4-hydroxybenzophenone (4-HBP), 3-(4-methylbenzylidene)-camphor (4-MBC), and 3-benzylidene camphor (3-BC) by LC-MS/MS.

RESULTS

Of the analysed UV filters, the children excreted predominantly BP-1, BP-3 and 4-HBP. The urine levels were significantly higher in summer samples compared to winter samples, however exposure during winter was still evident. Furthermore, children with the highest concentrations of UV filters in summer urines also tended to be among those with the highest winter levels.

CONCLUSION

Exposures to UV filters during summertime can partly be explained by the intended use of UV filters in sunscreens, which is considered to be beneficial for children during outdoor activities. However, exposure to UV filters all year round together with large inter-individual variation indicate that children's exposure to UV filters also comes from other consumer items, presumably highly influenced by the general lifestyle of an individual child: this is completely unintended, without benefit, and potentially harmful.

Exposure of children to BPA through dust and the association of urinary BPA and triclosan with oxidative stress in Guangzhou, China

Both bisphenol A (BPA) and triclosan (TCS) are phenolic compounds widely used in a variety of household applications. These compounds could be released into the environment, enter the human body and cause a series of potential health hazards. Children are sensitive and susceptible to these contaminants. To investigate the potential oxidative DNA damage from exposure to BPA and TCS, ninety six urine samples of children (aged 3-6) and 57 dust samples were collected from a kindergarten in Guangzhou, China. The concentrations of urinary BPA, TCS and 8-hydroxy-2'-deoxyguanosine (8-OHdG, a biomarker of oxidative DNA damage) in urine were determined using a liquid chromatography tandem mass spectrometer. The geometric mean concentrations of urinary BPA, TCS and 8-OHdG were 1.08 μg L^-1, 1.34 μg L^-1 and 1.90 μg L^-1, respectively. The results showed that both BPA and TCS exposures were associated with oxidative damage. Significant dose-effects existed between the urinary BPA, TCS levels and the 8-OHdG concentrations. Multiple linear regression analysis showed that one percent increase in BPA and in TCS could generate 0.15% and 0.081% increase in 8-OHdG in urine for children in Guangzhou. We also determined the concentrations of BPA in dust using high performance liquid chromatography. The mean concentration of BPA was 2.86 μg g^-1 in indoor dust and 3.23 μg g^-1 in outdoor dust. The dust contributes approximately 9.23% to the urinary BPA exposure for the children. In conclusion, BPA and TCS exposure correlates with oxidative DNA damage.

Juvenile Male Rats Exposed to a Low-Dose Mixture of Twenty-Seven Environmental Chemicals Display Adverse Health Effects

Humans are exposed to a large number of environmental chemicals in their daily life, many of which are readily detectable in blood or urine. It remains uncertain if these chemicals can cause adverse health effects when present together at low doses. In this study we have tested whether a mixture of 27 chemicals administered orally to juvenile male rats for three months could leave a pathophysiological footprint. The mixture contained metals, perfluorinated compounds, PCB, dioxins, pesticides, heterocyclic amines, phthalate, PAHs and others, with a combined dose of 0.16 (Low dose), 0.47 (Mid dose) or 1.6 (High dose) mg/kg bw/day. The lowest dose was designed with the aim of obtaining plasma or urine concentrations in rats at levels approaching those observed in humans. Some single congeners were administered at doses representative of combined doses for chemical groups. With this baseline, we found effects on weight, histology and gene expression in the liver, as well as changes to the blood plasma metabolome in all exposure groups, including low-dose. Additional adverse effects were observed in the higher dosed groups, including enlarged kidneys and alterations to the metabolome. No significant effects on reproductive parameters were observed.

Prenatal Triclosan Exposure and Anthropometric Measures Including Anogenital Distance in Danish Infants

BACKGROUND

Triclosan (TCS) is widely used as an antibacterial agent in consumer products such as hand soap and toothpaste, and human exposure is widespread. TCS is suspected of having endocrine-disrupting properties, but few human studies have examined the developmental effects of prenatal TCS exposure.

OBJECTIVES

We prospectively examined associations between prenatal TCS exposure and anthropometric measures at birth and anogenital distance (AGD) at 3 months of age.

METHODS

Pregnant women from the Odense Child Cohort (n = 514) provided urine samples at approximately gestational week 28 (median 28.7 weeks, range 26.4-34.0), and urinary TCS concentration was measured by isotope dilution TurboFlow-liquid chromatography-tandem mass spectrometry. Multiple linear regression analysis was used to examine associations between prenatal TCS exposure and measures of size at birth (birth weight, length, head and abdominal circumference) and AGD at 3 months of age (median 3.3 months, range 2.3-6.7 months), controlling for potential confounders.

RESULTS

Newborn boys in the highest quartile of prenatal TCS exposure had a 0.7-cm [95% confidence interval (CI): -1.2, -0.1, p = 0.01] smaller head circumference than boys in the lowest quartile. Additionally in boys, inverse associations of borderline statistical significance were observed between prenatal TCS exposure and abdominal circumference at birth and AGD at 3 months of age (p-values < 0.10). Prenatal TCS exposure was not significantly associated with any of the outcomes in girls. However, AGD was measured in fewer girls, and we observed no significant interactions between a child's sex and prenatal TCS exposure in anthropometric measures at birth.

CONCLUSION

Prenatal TCS exposure was associated with reduced head and abdominal circumference at birth and with reduced AGD at 3 months of age in boys, although the last two findings were statistically nonsignificant. These findings require replication but are compatible with an anti-androgenic effect of prenatal TCS exposure on fetal growth in boys.

CITATION

Lassen TH, Frederiksen H, Kyhl HB, Swan SH, Main KM, Andersson AM, Lind DV, Husby S, Wohlfahrt-Veje C, Skakkebæk NE, Jensen TK. 2016. Prenatal triclosan exposure and anthropometric measures including anogenital distance in Danish infants. Environ Health Perspect 124:1261-1268; http://dx.doi.org/10.1289/ehp.1409637.

Patterns, Variability, and Predictors of Urinary Bisphenol A Concentrations during Childhood

We examined the patterns, variability, and predictors of urinary bisphenol A (BPA) concentrations in 337 children from the Cincinnati, Ohio HOME Study. From 2003 to 2014, we collected two urine samples from women at 16 and 26 weeks of pregnancy and six urine samples from children at 1-5 and 8 years of age. We used linear mixed models to calculate intraclass correlation coefficients (ICCs) as a measure of within-person BPA variability and to identify sociodemographic and environmental predictors. For the 8-year visit, we used multivariable linear regression to explore associations between urinary BPA concentrations and exposure-related factors. We calculated daily intakes using equations estimating creatinine excretion rates and creatinine-standardized BPA concentrations. Urinary BPA concentrations, which decreased over childhood, had a low degree of reproducibility (ICC < 0.2). Estimated daily intakes decreased with age and were below the reference dose of 50 μg/kg body weight/day. BPA concentrations were positively associated with consuming food stored or heated in plastic, consuming canned food and beverages, and handling cash register receipts. Our results suggest that there are multiple sources of BPA exposure in young children. Etiological studies should collect serial urine samples to accurately classify BPA exposure and consider sociodemographic and environmental factors as possible confounders.

Determination of free and conjugated forms of endocrine-disrupting chemicals in human biological fluids by GC−MS

Background: Humans are exposed to hazardous substances including endocrine-disrupting chemicals (EDCs). These compounds have been associated with some diseases such as cancer and ascribed adverse effects on life-essential organs. Results: The method, which allows the determination of both free and conjugated forms of EDCs, involves the liquid–liquid extraction from the sample with ethyl acetate, followed by its preconcentration and clean-up by SPE in a continuous system for the subsequent determination by GC–MS. The proposed method affords very low LODs and RSD. Conclusion: This allowed its successful application to the determination of EDCs in human urine, blood and breast milk. The most frequently founded were methylparaben, ethylparaben, bisphenol A and triclosan.

Delayed Neuroendocrine Sexual Maturation in Female Rats After a Very Low Dose of Bisphenol A Through Altered GABAergic Neurotransmission and Opposing Effects of a High Dose

Rat sexual maturation is preceded by a reduction of the interpulse interval (IPI) of GnRH neurosecretion. This work aims at studying disruption of that neuroendocrine event in females after early exposure to a very low dose of bisphenol A (BPA), a ubiquitous endocrine disrupting chemical. Female rats were exposed to vehicle or BPA 25 ng/kg·d, 25 μg/kg·d, or 5 mg/kg·d from postnatal day (PND)1 to PND5 or PND15. Exposure to 25 ng/kg·d of BPA for 5 or 15 days was followed by a delay in developmental reduction of GnRH IPI studied ex vivo on PND20. After 15 days of exposure to that low dose of BPA, vaginal opening tended to be delayed. In contrast, exposure to BPA 5 mg/kg·d for 15 days resulted in a premature reduction in GnRH IPI and a trend toward early vaginal opening. RNA sequencing analysis on PND20 indicated that exposure to BPA resulted in opposing dose effects on the mRNA expression of hypothalamic genes involved in gamma aminobutyric acid A (GABAA) neurotransmission. The study of GnRH secretion in vitro in the presence of GABAA receptor agonist/antagonist confirmed an increased or a reduced GABAergic tone after in vivo exposure to the very low or the high dose of BPA, respectively. Overall, we show for the first time that neonatal exposure to BPA leads to opposing dose-dependent effects on the neuroendocrine control of puberty in the female rat. A very low and environmentally relevant dose of BPA delays neuroendocrine maturation related to puberty through increased inhibitory GABAergic neurotransmission.

Determination of parabens and benzophenone-type UV filters in human placenta. First description of the existence of benzyl paraben and benzophenone-4

UV filters and parabens (PBs) are chemicals used in daily personal care and hygiene products to protect materials and humans from the adverse effects of UV radiation and to preserve the integrity of the formulation, respectively. Several studies highlight their widespread environmental occurrence and endocrine disrupting effects. However, little is known about human exposure to these compounds. The objective of this study was to investigate the exposure of human embryos and foetuses to endocrine disrupting UV filters and PBs. Placentas from volunteer mothers in Barcelona were collected at delivery after informed, written consent by the pregnant women. UV filters and parabens were analysed by liquid chromatography-tandem mass spectrometry. The excellent performance of the method allowed measuring the target compounds in human placental tissue at low ng/g fresh weight level. The detection frequency of the selected compounds was in the range 17-100%. Benzophenone-1, methyl paraben, butyl paraben and benzyl paraben were detected in all samples. The highest measured concentration corresponded to methyl paraben, 11.77ng/g fresh weight. Reported concentrations of benzophenone-4 and benzyl paraben constitute the first evidence about their accumulation in placenta. The results obtained corroborate that foetuses are exposed to a wide diversity of UV filters and PBs via the placenta.

Human biomonitoring of bisphenol A exposure in an Austrian population

Bisphenol A (BPA) is an industrial chemical widely used as a monomer in polycarbonate, epoxy resin and thermal paper production, and as a stabiliser in polyvinyl chloride (PVC) production. Thus, BPA is present in a wide range of common consumer products. Due to contact with BPA-containing products, humans are regularly exposed via different routes. BPA is an endocrine active substance and can potentially lead to different adverse health outcomes. In the present study, total BPA levels were analysed by on-line SPE-HPLC-MS/MS in spontaneous urine samples in order to investigate the exposure to an Austrian population aged 6-15 and 18-81 years. In the total study population (n=594), total BPA were found in 15.7% of all samples, with concentrations up to 17 μg/l (median: n.d., 95th percentile: 3.7 μg/l). These results show generally low BPA levels among the investigated study population. However, children and adolescents exhibited higher exposure levels. Daily BPA intakes were estimated and compared to acceptable exposure levels, whereat no exceedances could be identified. Although BPA exposure was shown to be low in the Austrian population, the wide distribution and the ongoing discussion related to possible negative health effects even at low doses indicate need for further monitoring and investigations.

Urinary BPA measurements in children and mothers from six European member states: Overall results and determinants of exposure

For the first time in Europe, both European-wide and country-specific levels of urinary Bisphenol A (BPA) were obtained through a harmonized protocol for participant recruitment, sampling and quality controlled biomarker analysis in the frame of the twin projects COPHES and DEMOCOPHES. 674 child-mother pairs were recruited through schools or population registers from six European member states (Belgium, Denmark, Luxembourg, Slovenia, Spain and Sweden). Children (5-12 y) and mothers donated a urine sample. Information on socio-demographic characteristics, life style, dietary habits, and educational level of the parents was provided by mothers. After exclusion of urine samples with creatinine values below 300 mg/L or above 3000 mg/L, 653 children and 639 mothers remained for which BPA was measured. The geometric mean (with 95% confidence intervals) and 90th percentile were calculated for BPA separately in children and in mothers and were named "European reference values". After adjustment for confounders (age and creatinine), average exposure values in each country were compared with the mean of the "European reference values" by means of a weighted analysis of variance. Overall geometric means of all countries (95% CI) adjusted for urinary creatinine, age and gender were 2.04 (1.87-2.24) µg/L and 1.88 (1.71-2.07) µg/L for children (n=653) and mothers (n=639), respectively. Multiple regression analysis was used to identify significant environmental, geographical, personal or life style related determinants. Consumption of canned food and social class (represented by the highest educational level of the family) were the most important predictors for the urinary levels of BPA in mothers and children. The individual BPA levels in children were significantly correlated with the levels in their mothers (r=0.265, p<0.001), which may suggest a possible common environmental/dietary factor that influences the biomarker level in each pair. Exposure of the general European population was well below the current health-based guidance values and no participant had BPA values higher than the health-based guidance values.

The Danish contribution to the European DEMOCOPHES project: A description of cadmium, cotinine and mercury levels in Danish mother-child pairs and the perspectives of supplementary sampling and measurements

Human biomonitoring (HBM) is an important tool, increasingly used for measuring true levels of the body burdens of environmental chemicals in the general population. In Europe, a harmonized HBM program was needed to open the possibility to compare levels across borders. To explore the prospect of a harmonized European HBM project, DEMOCOPHES (DEMOnstration of a study to COordinate and Perform Human biomonitoring on a European Scale) was completed in 17 European countries. The basic measurements performed in all implemented countries of DEMOCOPHES included cadmium, cotinine and phthalate metabolites in urine and mercury in hair. In the Danish participants, significant correlations between mothers and children for mercury in hair and cotinine in urine were found. Mercury in hair was further significantly associated with intake of fish and area of residence. Cadmium was positively associated with BMI in mothers and an association between cadmium and cotinine was also found. As expected high cotinine levels were found in smoking mothers. For both mercury and cadmium significantly higher concentrations were found in the mothers compared to their children. In Denmark, the DEMOCOPHES project was co-financed by the Danish ministries of health, environment and food safety. The co-financing ministries agreed to finance a number of supplementary measurements of substances of current toxicological, public and regulatory interest. This also included blood sampling from the participants. The collected urine and blood samples were analyzed for a range of other persistent and non-persistent environmental chemicals as well as two biomarkers of effect. The variety of supplementary measurements gives the researchers further information on the exposure status of the participants and creates a basis for valuable knowledge on the pattern of exposure to various chemicals.

Benzonphenone-type UV filters in urine of Chinese young adults: Concentration, source and exposure

Benzophenone (BP)-type UV filters are commonly used in our daily life. 2-hydroxy-4-methoxy benzophenone (BP-3), 4-hydroxy benzophenone (4-HBP), 2,4-dihydroxy benzophenone (BP-1), 2,2',4,4'-tetrahydroxy benzophenone (BP-2) and 2,2'-dihydroxy-4-methoxy benzophenone (BP-8) were measured in urine samples from Chinese young adults. The results indicated that Chinese young adults were widely exposed to BP-3, BP-1, and 4-HBP, with the median concentrations of 0.55, 0.21, and 0.08 ng/mL, respectively. No significant difference was found between males and females, between urban and rural population. The correlations between urinary concentrations provided important indications for sources and metabolic pathways of target compounds. The estimated daily excretion doses of BP-3, 4-HBP, BP-1, BP-2 and BP-8 were 27.2, 2.24, 5.86, 0.76 and 0.30 ng/kg-bw/day, respectively. The ratio of exposure to excretion must be considered for the exposure assessment with chemicals based on urine measurement. This is the first nationwide study on BP-derivatives with young adults in China.

Simultaneous determination of aflatoxin B1 and M1 in milk, fresh milk and milk powder by LC-MS/MS utilising online turbulent flow chromatography

A novel, fully automated method based on dual-column switching using online turbulent flow chromatography followed by LC-MS/MS was developed for the determination of aflatoxin B1 and M1 in milk, fresh milk and milk powder samples. After ultrasound-assisted extraction, samples were directly injected into the chromatographic system and the analytes were concentrated on the clean-up loading column. Through purge switch, analytes were transferred to the analytical column for subsequent detection by mass spectrometry. Different types of TurboFlow(TM) columns, transfer flow rates and transfer times were optimised. Method limits of detection obtained for AFB1 and AFM1 were 0.05 μg kg(-1), and limits of quantification were 0.1 μg kg(-1). Recoveries of aflatoxin B1 and M1 were in range of 81.1-102.1% for all samples. Matrix effects of aflatoxin B1 and M1 were in range of 63.1-94.3%. The developed method was successfully used for the analysis of aflatoxin B1 and M1 in real samples.

Urinary concentrations of benzophenone-type ultraviolet radiation filters and couples' fecundity

Concern has arisen about benzophenone (BP) ultraviolet (UV) radiation filters, given their use in sunscreen and personal-care products and their reported estrogenic and antiandrogenic activity. We recruited 501 couples who were discontinuing use of contraceptives in order to become pregnant for the Longitudinal Investigation of Fertility and the Environment (LIFE) Study (Michigan and Texas, 2005-2009). Couples provided urine specimens and completed daily journals until they either achieved pregnancy or had tried for 12 months. Women used fertility monitors to time sexual intercourse and digital pregnancy tests. Urinary concentrations of 5 UV filters (ng/mL) were determined using triple-quadrupole mass spectrometry: 2,4-dihydroxybenzophenone (also called BP-1); 2,2',4,4'-tetrahydroxybenzophenone (BP-2); 2-hydroxy-4-methoxybenzophenone (BP-3); 2,2'-dihydroxy-4-methoxybenzophenone (BP-8); and 4-hydroxybenzophenone. Fecundability odds ratios were estimated for each UV filter (dichotomized at the 75th percentile) and adjusted for age, creatinine concentration, body mass index (weight (kg)/height (m)(2)), cotinine concentration, season, and site, while accounting for time off contraception. Separate models were fitted for each UV filter and partner; final models included partners' concentrations. Male partners' concentrations of BP-2 and 4-hydroxybenzophenone were associated with reduced fecundity in adjusted models (fecundability odds ratio (FOR) = 0.69 (95% confidence interval (CI): 0.50, 0.95) and FOR = 0.74 (95% CI: 0.54, 1.00), respectively). In models adjusting for both partners' concentrations, male BP-2 concentration remained associated with reduced fecundity (FOR = 0.69, 95% CI: 0.49, 0.97). These data suggest that male exposure to select UV filters may diminish couples' fecundity, resulting in a longer time to pregnancy.

Exposure to bisphenol A among school children in eastern China: a multicenter cross-sectional study

Bisphenol A (BPA) is one of the highest production and consumption volume chemicals in the world. Although exposure of children to BPA has been studied in Western countries, little is known about its level in China. In this study, total BPA was measured in the morning urine samples of 666 school children aged 9-12 years from three regions in eastern China in 2012. A rapid and sensitive ultraperformance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) method was used for the measurement and urinary concentrations of BPA were presented as unadjusted (ng/ml), creatinine-adjusted (μg/g creatinine) and specific gravity (SG)-adjusted (ng/ml) forms. BPA was detected in 98.9% of urine samples with their unadjusted concentrations ranging from 0.1 to 326.0 ng/ml (LOD=0.06 ng/ml), indicating that the exposure of BPA was common for school children living in eastern China. The geometric mean and median of BPA was 1.11 ng/ml (creatinine-adjusted: 2.32 μg/g creatinine; SG-adjusted: 1.17 ng/ml) and 1.00 ng/ml (creatinine-adjusted: 2.22 μg/g creatinine; SG-adjusted: 1.07 ng/ml), respectively. The highest urinary BPA level was found in the age group of 12 years with GM concentration of 1.55 ng/ml, and it decreased with decreasing age (11 years: 1.18 ng/ml; 10 years: 1.05 ng/ml; and 9 years: 0.99 ng/ml), but there was a lack of consistency for age associated with BPA levels in three study areas. The estimated daily intake of BPA (0.023 μg/kg bw/day) was much lower than the tolerable daily and reference dose of 50 μg/kg bw/day recommended by either the European Food Safety Authority or the US Environment Protection Agency. There was no significant difference in urinary BPA concentrations between children who were overweight or obese and those with normal weight (P=0.26), whereas BPA daily intake was unexpectedly higher among normal-weight children (P=0.003). Compared with creatinine correction, the correction method of specific gravity is preferred to evaluate BPA exposure for children.

Fast analysis of polyphenols in royal jelly products using automated TurboFlow™-liquid chromatography-Orbitrap high resolution mass spectrometry

This study describes the development of a novel, simple and fast analytical method for the detection and quantification of polyphenols in royal jelly products, using an in-house database containing more than 50 compounds. The extraction method consisted of sample dilution, followed by a fast on-line system composed of turbulent flow chromatography (TurboFlow™) coupled to liquid chromatography (LC)-Exactive-Orbitrap analyzer. The total run time was 18min, including automated extraction, analytical chromatography and re-equilibration. The method was validated obtaining limits of quantification (LOQ) ranging from 10 to 150μg/kg. The linearity range was up to 2000μg/L and determination coefficients (R²) were higher than 0.994. Adequate recoveries were obtained at three concentration levels (500, 1000 and 2000μg/kg). This method was applied to the analysis of nine samples and the concentration of polyphenols ranged from 14 (apigenin) to 18,936μg/kg (ferulic acid).

Two polydimethylsiloxane rod extraction methods for the sensitive determination of phenolic compounds in water samples

Simple, precise, and low-cost methods for the simultaneous determination of phenolic endocrine disrupting compounds such as bisphenol A, trichlorophenol, pentachlorophenol, 4-nonylphenol, and 4-octylphenol in water samples were developed. The Direct, in situ derivatization methods are based on polydimethylsiloxane rod extraction followed by liquid desorption and chromatographic analysis by liquid chromatography and diode array detection. Several parameters affecting the extraction and desorption of the phenolic compounds and their acetylated derivates were studied, as well as the chromatographic and detection conditions. For the direct method, determination coefficients (r(2) ) > 0.990 and LODs in the 0.6-2 μg/L range were obtained for all compounds except bisphenol A (9.5 μg/L). With the derivatization-based method, based on in situ acetylation, lower limits of detection (0.3-0.9 μg/L) were obtained for all the compounds with r(2) > 0.988 and RSDs in the 2-9% range. The developed methods were applied to the analysis of spiked water samples obtaining recoveries of between 60.2 and 131.7% for the direct method, and of between 76.6 and 108.2% for the derivatization-based method. The results demonstrate the feasibility of using these two methods for determining bisphenol A, trichlorophenol, pentachlorophenol, 4-nonylphenol, and 4-octylphenol in water.

Determinants of bisphenol A and phthalate metabolites in urine of Flemish adolescents

As part of the second Flemish Environment and Health Study (FLEHS II), bisphenol-A (BPA) and different phthalate metabolites were analyzed, for the first time, in the urine of 210 adolescents in Flanders, Belgium. All chemicals had a detection frequency above 90%. For all compounds, except the sum of DEHP, highest levels were detected during spring. Average values for the Flemish adolescents were in an agreement with concentrations found in different international studies, all confirming the ubiquity of BPA and phthalate exposure. There was a significant correlation between BPA and the different phthalate metabolites (r between 0.26 and 0.39; p<0.01). Shared sources of exposure to BPA and phthalates, such as food packaging, were suggested to be responsible for this positive correlation. Different determinants of exposure were evaluated in relation to the urinary concentrations of these chemicals. For BPA, a significant association was observed with household income class, smoking and exposure to environmental tobacco smoke. For phthalates, the following significant associations were observed: age (MBzP), educational level of the adolescent (MBzP), equivalent household income (MnBP), use of personal care products (MnBP and MBzP), wall paper in house (MnBP and MBzP) and use of local vegetables (MnBP and MBzP).

Occurrences, toxicities, and ecological risks of benzophenone-3, a common component of organic sunscreen products: a mini-review

Benzophenone-3 (BP-3) has been widely used in sunscreens and many other consumer products, including cosmetics. The widespread use of BP-3 has resulted in its release into the water environment, and hence its potential impact on aquatic ecosystem is of concern. To better understand the risk associated with BP-3 in aquatic ecosystems, we conducted a thorough review of available articles regarding the physicochemical properties, toxicokinetics, environmental occurrence, and toxic effects of BP-3 and its suspected metabolites. BP-3 is lipophilic, photostable, and bioaccumulative, and can be rapidly absorbed via oral and dermal routes. BP-3 is reported to be transformed into three major metabolites in vivo, i.e., benzophenone-1 (BP-1), benzophenone-8 (BP-8), and 2,3,4-trihydroxybenzophenone (THB). BP-1 has a longer biological half-life than its parent compound and exhibits greater estrogenic potency in vitro. BP-3 has been detected in water, soil, sediments, sludge, and biota. The maximum detected level in ambient freshwater and seawater is 125ng/L and 577.5ng/L, respectively, and in wastewater influent is 10,400ng/L. The major sources of BP-3 are reported to be human recreational activities and wastewater treatment plant (WWTP) effluents. BP-3 and its derivatives have been also detected in fish lipid. In humans, BP-3 has been detected in urine, serum, and breast milk samples worldwide. BP-1 has also been detected in placental tissues of delivering women. While sunscreens and cosmetics are known to be major sources of exposure, the fact that BP-3 has been detected frequently among young children and men suggests other sources. An increasing number of in vitro studies have indicated the endocrine disrupting capacity of BP-3. Based on a receptor binding assay, BP-3 has shown strong anti-androgenic and weak estrogenic activities but at the same time BP-3 displays anti-estrogenic activity as well. Predicted no effect concentration (PNEC) for BP-3 was derived at 1.32μg/L. The levels observed in ambient water are generally an order of magnitude lower than the PNEC, but in wastewater influents, hazard quotients (HQs) greater than 1 were noted. Considering limited ecotoxicological information and significant seasonal and spatial variations of BP-3 in water, further studies on environmental monitoring and potential consequences of long-term exposure in aquatic ecosystem are warranted.

Urinary bisphenol A levels in young men: association with reproductive hormones and semen quality

BACKGROUND

Few human studies have examined bisphenol A (BPA) exposure in relation to semen quality and reproductive hormones in men, and results are divergent.

OBJECTIVES

We examined associations between urinary BPA concentration and reproductive hormones, as well as semen quality, in young men from the general population.

METHODS

Our study population consisted of 308 young men from the general population. Urinary BPA concentration was measured by isotope dilution TurboFlow-liquid chromatography-tandem mass spectrometry. We used multiple linear regression analysis to estimate associations between BPA concentration and reproductive hormones and semen quality, adjusting for confounding factors.

RESULTS

We found that 98% of the men had detectable urinary levels of BPA. Median (5th-95th percentiles) BPA concentration was 3.25 ng/mL (0.59-14.89 ng/mL). Men with BPA concentrations above the lowest quartile had higher concentrations of serum testosterone, luteinizing hormone (LH), estradiol, and free testosterone compared with the lowest quartile (p trend ≤ 0.02). Men in the highest quartile of BPA excretion had on average 18% higher total testosterone (95% CI: 8, 28%), 22% higher LH (95% CI: 6, 39%), and 13% higher estradiol (95% CI: 4, 24%) compared with lowest quartile. Men in the highest quartile of BPA also had significantly lower percentage progressive motile spermatozoa compared with men in the lowest quartile (-6.7 percentage points, 95% CI: -11.76, -1.63). BPA was not associated with other semen parameters. Adjusting for dietary patterns did not influence the results.

CONCLUSIONS

The pattern of associations between BPA and reproductive hormones could indicate an antiandrogenic or antiestrogenic effect, or both, of BPA on the hypothalamic-pituitary-gonadal hormone feedback system, possibly through a competitive inhibition at the receptor level. However, additional research is needed to confirm our findings and to further test the suggested potential mechanisms.