S-Space College of Medicine/School of Medicine (의과대학/대학원) Preventive Medicine (예방의학전공) Journal Papers (저널논문_예방의학전공)
Relationship between Environmental Phthalate Exposure and the Intelligence of School-Age Children
- Cho, Soo-Churl; Bhang, Soo-Young; Hong, Yun-Chul; Shin, Min-Sup; Kim, Jae-Won; Cho, In Hee; Kim, Hyo-Won; Yoo, Hee-Jung; Kim, Boong-Nyun
- Issue Date
- ENVIRONMENTAL HEALTH PERSPECTIVES; Vol.118 7; 1027-1032
- children; cognition; sex; phthalate; mono-n-butyl phthalate (MBP); mono(2-ethyl-5-oxohexyl) phthalate (MEOHP); mono-2-ethylhexyl phthalate (MEHP); IQ; di(2-ethylhexyl)phthalate (DEHP); dibutyl phthalate (DBP)
- BACKGROUND: Concern over phthalates has emerged because of their potential toxicity to humans. OBJECTIVE: We investigated the relationship between the urinary concentrations of phthalate metabolites and children`s intellectual functioning. METHODS: This study enrolled 667 children at nine elementary schools in five South Korean cities. A cross-sectional examination of urine phthalate concentrations was performed, and scores on neuro-psychological tests were obtained from both the children and their mothers. RESULTS: We measured mono-2-ethylhexyl phthalate (MEHP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), both metabolites of di(2-ethylhexyl)phthalate (DEHP), and mono-n-butyl phthalate (MBP), a metabolite of dibutyl phthalate (DBP), in urine samples. The geometric mean (ln) concentrations of MEHP, MEOHP, and MBP were 21.3 mu g/L [geometric SD (GSD) = 2.2 mu g/L; range, 0.5-445.4], 18.0 mu g/L (GSD = 2.4; range, 0.07-291.1), and 48.9 mu g/L (GSD = 2.2; range, 2.1-1645.5), respectively. After adjusting for demographic and developmental covariates, the Full Scale IQ and Verbal IQ scores were negatively associated with DEHP metabolites but not with DBP metabolites. We also found a significant negative relationship between the urine concentrations of the metabolites of DEHP and DBP and children`s vocabulary subscores. After controlling for maternal IQ, a significant inverse relationship between DEHP metabolites and vocabulary subscale score remained. Among boys, we found a negative association between increasing MEHP phthalate concentrations and the sum of DEHP metabolite concentrations and Wechsler Intelligence Scale for Children vocabulary score; however, among girls, we found no significant association between these variables. CONCLUSION: Controlling for maternal IQ and other covariates, the results show an inverse relationship between phthalate metabolites and IQ scores; however, given the limitations in cross-sectional epidemiology, prospective studies are needed to fully explore these associations.