Biomonitoring, dietary predictors, drinking water ingestion of 33 endocrine disrupting chemicals in primary school children in China, towards an exposome approach

Exposure to multiple endocrine-disrupting chemicals (EDCs) may have some adverse impacts on child health; yet, little data is available on the body burdens, co-exposure patterns, health risks, and possible sources of a broad range of EDCs in school-age children. A total of 33 chemicals including 3 non-specific pyrethroid pesticide metabolites, 2 specific organophosphorus pesticide metabolites, 5 chlorophenols, 4 phenols, 5 parabens and 14 toxic and essential elements were quantified in urine. A 24-hour dietary recall survey was conducted to collect dietary information, and seven food categories were classified accordingly. Multivariable linear regression models were applied to estimate associations of dietary information and drinking water types with urinary EDC concentrations. A total of 31 chemicals were detected in more than 50 % of urinary samples. The number of 10 (2.44 %), 32 (7.80 %), 4 (0.98 %), 20 (4.88 %), and 3 (0.73 %) children who experienced exposure levels of over 75th percentiles was found, for pesticides, phenols, parabens, selected toxic elements and these chemical mixtures, respectively. The consumption of dairy products was positively associated with urinary 2,4,6-trichlorophenol concentrations. Meat and meat products and vegetable consumption predicted higher urinary concentrations of methyl- and ethyl-paraben, respectively. Cereal intakes were positively associated with urinary cadmium, arsenic and cobalt levels, and the consumption of aquatic products was in relation to increases of urinary lead and cadmium concentrations. Children who mainly drank filtered water had lower urinary concentrations of chlorpyrifos metabolite and bisphenol A, while those with bottled water as the main drinking water source had higher 2,4-dichlorophenol concentrations and lower selenium levels in urine, compared to those who mainly drank tap water. Our findings suggested that children in this area were widely exposed to multiple classes of EDCs, and diet and drinking water were potential exposure sources of the analyzed chemicals.