Biomonitoring of Phthalates, Bisphenols and Parabens in Children: Exposure, Predictors and Risk Assessment.

Exposure to emerging contaminants, such as phthalates, bisphenols and parabens in children has been associated with possible neurodevelopment and endocrine alterations. In the present study, the biomonitoring of biomarkers in children (5-12 years old) from the Valencia Region (Spain) have been implemented using urines from the BIOVAL program. More than 75% of the children studied (n = 562) were internally exposed (>LOQ) to bisphenols and parabens, and the whole population assessed (n = 557) were exposed to at least one phthalate. The geometric means (GM) of the concentrations of bisphenol A, methyl paraben and propyl paraben were 0.9, 1.4 and 0.39 ng/mL, respectively. Regarding phthalates, monoethyl phthalate GM was 55.0 ng/mL and diethyl hexyl phthalate (as the sum of five metabolites) GM was 60.6 ng/mL. Despite the studied population being widely exposed, the detection frequencies and concentrations were in general lower than in previous studies involving children in Spain and in other countries in recent years. Furthermore, the risk assessment study concluded that the internal exposure to phthalates, bisphenols and parabens is lower than the guidance values established, and, therefore, a health risk derived from the exposure to these compounds in the studied population is not expected.

Children's exposure to polycyclic aromatic hydrocarbons in the Valencian Region (Spain): Urinary levels, predictors of exposure and risk assessment.

Polycyclic aromatic hydrocarbons (PAHs) are pollutants that are released into the environment during incomplete combustion of organic matter and which can have a negative effect on human health. PAHs enter the human body mostly through ingestion of food or inhalation of tobacco smoke. The purpose of the present study is to evaluate the internal levels of PAHs that children living in the Valencian Region (Spain) are exposed to. In total, we measured eleven biomarkers of exposure to naphthalene, fluorene, phenanthrene, pyrene, and benzo(a)pyrene in the urine of 566 children aged 5-12. The analytical method was based on a liquid-liquid extraction of the PAH metabolites from the urine samples, followed by their determination by liquid chromatography coupled to tandem mass spectrometry. In addition, we used a questionnaire to collect the socio-demographic characteristics and 72 h dietary recall information of the participants in our study. Overall, we detected PAH metabolites in more than 78% of the children, with the exception of 3-hydroxyfluorene and 3-hydroxybenzo(a)pyrene, which were found in less than 37% of the analyzed samples. The most abundant biomarker found was 2-hydroxynaphthalene, with a geometric mean of 10 ng·ml-1. Reference values (RV95) ranging from 0.11 (4-hydroxyphenanthrene) to 53 ng·ml-1 (2-hydroxynaphthalene) in urine of Spanish children were derived from the present study. According to the statistical analysis, the factors that were significantly associated with the internal exposure to PAHs were province of residence, body mass index (BMI), children's age, consumption of plastic-wrapped food, and dietary habits. The estimated daily intakes in geometric mean terms ranged from 5 (fluorene) to 204 ng·kg-bw-1·day-1 (naphthalene). Risk assessment calculations showed higher hazard quotients and hazard indexes for children aged 5-8 than those aged 9-12, but all were below 1. In conclusion, no potential non-cancer health risk due to PAH exposure was observed in children living in Spain.

Dioxins and dioxin-like PCBs in the ambient air of the Valencian Region (Spain): Levels, human exposure, and risk assessment.

Dioxins (polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), as well as dioxin-like PCBs (dl-PCBs), are listed as persistent organic pollutants in the Stockholm Convention. In this study, we measured their concentrations in the particulate phase (PM10) of the ambient air in seven monitoring stations of the Valencian Community (Spain). A total of 82 samples were collected from different sampling sites: four industrial, two urban, and one remote, from February to December 2019. The total concentrations of the sum of PCDD, PCDF, and dl-PCBs ranged from 2.90 fg TEQ/m3 to 317.98 fg TEQ/m3. Risk assessment for adults and children was performed using both daily and chronic exposure. Each station showed its specific dioxin profile, related to the main productive activities in each area. The daily inhalation dose (DID) in adults and children was lower than the tolerable daily intake (TDI) of 1-4 pg WHO TEQ kg-1 b.w. d-1 for dioxins. In the case of chronic exposure, the cancer risk for dioxins and dl-PCBs was estimated at values ranging from 5.27 E-07 to 5.52 E-05. The cancer risk for dioxins and PCBs estimated at the 95th percentile was higher than 1.0 E-06 in all of the industrial and urban areas.

Biomonitoring of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in human milk: Exposure and risk assessment for lactating mothers and breastfed children from Spain.

The main objective of the present research was to evaluate the levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in the human milk of Spanish lactating women who participated in the BETTERMILK project so that exposure and risk could be assessed for these mothers and their breastfed children. The total ∑PCDD/Fs + dl-PCBs TEQ2005 concentrations in the upper-bound (UB) ranged from 1.29 to 13.48 pgTEQ2005 g-1 lipid. The estimated geometric mean level for the sum of PCDD/F and dl-PCBs was 4.10 and 4.42 pgTEQ2005 g-1 lipid, lower-bound (LB) and UB respectively and were below the reference level reported by EFSA, which is associated with adverse effects in boys of 9 years and related to lactating mothers' exposure values of the tolerable weekly intake (TWI) of around 2 pgTEQ2005 kg-1 bw per week. Nevertheless, it was exceeded when the 95th percentile (8.31 pgTEQ2005 g-1 lipid, as UB) was considered. Results from a multiple regression analysis showed that age has a significant impact on milk ∑PCDD/Fs + dl-PCBs levels, with higher concentrations observed in the milk from older mothers.