[Cumulative risk assessment of phthalates exposure in preschool children]

Objective: The urine concentrations of phthalate metabolites were used to estimate the cumulative risk assessment in preschool children in Ma'anshan of Anhui province. Methods: Based on the China-Anhui Birth Cohort, the demographic information and urine samples of 3 743 children were collected in Ma'anshan from April 2014 to April 2015. The concentrations of 7 metabolites' [monomethyl phthalate (MMP), monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), mono (2-ethylhexyl) phthalate (MEHP), mono (2-ethyl- 5-oxohexyl) phthalate (MEOHP) and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP)] of 5 phthalates [dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBzP), and di (2-ethylhexyl) phthalate (DEHP)] in the urine samples of the children were measured by solid-phase extration-triple quadrupole high performance liquid chromatography-tandem mass spectrometry-isotope method. In addition, the estimated daily intakes (EDIs) of 5 phthalates were calculated according to the metabolites' concentrations. Cumulative risk assessment was performed using hazard quotient (HQ) and hazard index (HI) methods. Results: The M (Q(R)) of seven metabolite concentrations were 29.58 (18.69-48.26), 26.65 (13.44-56.09), 256.86 (150.99-438.51), 0.12 (0.04-0.32), 6.27 (3.71-11.13), 17.94 (11.94-28.42) and 24.80 (16.05-40.32) μg/g creatinine, respectively. For the EDIs of 5 phthalates, DBP ranked first, followed by DEHP, DMP, DEP and BBzP with the M (Q(R)) of 7.54 (4.41-12.85), 3.35 (2.20-5.42), 0.75 (0.47-1.24), 0.71 (0.36-1.52) and 0.003 (0.001-0.009) μg/(kg·d), respectively. The HQ and HI varied with age, gender and sampling season, the differences were significant (P<0.05). Conclusions: These results indicated that risk of cumulative exposure to phthalates was high in preschool children aged 3-6 years in Ma'anshan. Age, gender and sampling season were influencing factors.