Intellectual evaluation of children exposed to phthalate-tainted products after the 2011 Taiwan phthalate episode.
Phthalate exposure may reduce intellectual development in young children. In 2011, numerous Taiwanese children had been reported to have consumed phthalate-tainted products. We investigated the effects of phthalate exposure on the intellectual development of these children after the 2011 Taiwan di-2-ethylhexyl phthalate (DEHP) episode.



We recruited 204 children, aged 3-12 y, from 3 hospitals in Taiwan between 2012 and 2013. First-morning urine samples were collected for analyzing 5 phthalate metabolites. We applied a Bayesian model to estimate the past DEHP exposure (estDEHPADD) of each participant before the 2011 DEHP episode. Demographic information, consumption of phthalate-tainted products, and maternal education, of each participant were obtained using a questionnaire. We used the Wechsler intelligence evaluation tools for assessing the children's and maternal intelligence quotient.



The median levels of mono-2-ethylhexyl phthalate, mono(2-ethyl-5-hydroxyhexyl) phthalate, mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-n-butyl phthalate, and mono-iso-butyl phthalate in the children were 9.97, 45.8, 32.2, 46.2, and 24.3μg/g creatinine, respectively. Using the aforementioned urinary phthalate metabolites, we found that the children's verbal comprehension index (N =98) was significantly negatively associated with urinary log10MEOHP (β, -11.92; SE, 5.33; 95%CI, -22.52~ -1.33; P=0.028) and log10ΣDBP metabolites (β, -10.95; SE, 4.93; 95%CI, -20.74~ -1.16; P=0.029) after adjustment for age, gender, maternal IQ and education, passive smoking,estDEHPADD, active and passive smoking during pregnancy. Through a tolerable daily intake-based approach, we only found a significant negative association between past estimate DEHPADDand VIQ≥3-<6in preschool children whereas no correlation was observed between current DEHP exposure and IQ≥3-<6score with/ without estimate DEHPADDadjustment. It revealed that the effect of past high-DEHP exposure on verbal-related neurodevelopment of younger child are more sensitive.



Our results are consistent with the hypothesis that exposure to DEHP and DnBP affects intellectual development in preschool and school-aged children, particularly their language learning or expression ability.
National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan; Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: pchuang@nhri.org.tw.
Po-Chin
PC
Huang
National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan.
Chih-Hsin
CH
Tsai
Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan.
Chu-Chih
CC
Chen
Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Family Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
Ming-Tsang
MT
Wu
Institute of Environmental and Occupational Health Sciences, National Yang Ming University, Taipei, Taiwan.
Mei-Lien
ML
Chen
National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan.
Shu-Li
SL
Wang
Department of Laboratory Medicine and Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Bai-Hsiun
BH
Chen
Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Research Center of Environmental Trace Toxic Substance, National Cheng Kung University, Tainan, Taiwan.
Ching-Chang
CC
Lee
Center for Environmental and Respiratory Health Research, Faculty of Medicine, University of Oulu, Oulu, Finland; Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland.
Jouni J K
JJK
Jaakkola
Department of Pediatrics, Taipei Hospital, Ministry of Health and Welfare, New Taipei,Taiwan.
Wen-Chiu
WC
Wu
Department of Pediatrics, Taichung Hospital, Ministry of Health and Welfare, Taichung, Taiwan.
Min-Kung
MK
Chen
Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan. Electronic address: hsiung@nhri.org.tw.
Chao A
CA
Hsiung
Members of the Risk Assessment of Phthalate Incident in Taiwan (RAPIT) Group.
Rapit
R
Group
D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D006801:Humans; D007360:Intelligence / Q000187:drug effects*; D008297:Male; D010795:Phthalic Acids / Q000633:toxicity*; D013624:Taiwan
D004785:Environmental Pollutants; D010795:Phthalic Acids
Children; Episode; Intellectual development; Phthalates