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 (QR) 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 (QR) 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. Key words: Phthalate; Preschool children; Cumulative risk assessment; Hazard index