Lead and other elements in the diet of children (aged 0-7 years) across 20 Chinese provinces at a home-level survey: seasonal variations of element levels and risks in food, urine, and feces in healthy individuals.

Diet is the principal source of individual Pb exposure; it contributes more than 80% of overall Pb intake. However, comprehensive understanding of the ingestions and risks of element mixtures from individual diet in younger children at a home-level remains limited. A total of 244 child volunteers aged 0-7 across 20 Chinese provinces were involved in this study; 18 elements (Ca, Mg, Fe, Zn, Cu, Mn, Cr, Co, Ni, V, As, Cd, Al, Hg, Sb, Tl, Ti, Pb) in food, urine, and feces collected in winter and summer seasons were firstly investigated at home levels. Results showed mean concentrations of all elements (except Al) in winter food are higher than those in summer, but food Cr and Pb exceeded China's national safety limits. Levels and associations between elements in food-urine-feces shift with seasons. Pairs of urine-Ni and urine-Cd, feces-Cd, and feces-Pb pose positive correlations in both seasons. However, urinary Ni and Cr show a negative correlation. Children's dietary element intake decreases after age 2 compared with other groups. Dietary Pb and Al intakes in both seasons exceed JECFA limits; especially, winter Pb intake for 2-3-year-olds exceeds by 2.2-fold limit. Fe, Cu, Mn, Co, Cd, As, Al, Ni, and Sb are excreted primarily in feces compared to Zn, Cr, and Pb excreted mainly in urine. Non-carcinogenic risks of As, Cr, and Pb and carcinogenic risks of Cr, Ni, Cd, and As are unacceptable for children in both seasons. Both MOE assessment and Monte Carlo simulation indicate higher exposure risks for younger children in winter. This study is the first to highlight regional and seasonal variations in dietary exposure to mixtures of elements and the associated ingestion risks for children aged 0-7 years in central China.