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Faculty of Health Sciences/
Graduate School of Health Sciences/
Department of Health Sciences,
School of Medicine,
Hokkaido University


[Research News] Exposure Trends to the Non-phthalate Plasticizers in Hokkaido Children (Dr. Ketema & Prof. Ikeda)

Key Points

◦ Phthalate substitutes DEHTP, DINCH, and DEHA exposure trend was examined.

◦ 2–5 times increase in exposure was observed from 2012–2017 in Japanese children.

◦ All the children’s EDI were below the TDI and Human biomonitoring guidelines.


Phthalates, chemicals used in plastic products, face regulation due to their disruption of the endocrine system including in Japan. Thus, phthalate substitutes such as di-2-ethylhexyl terephthalate (DEHTP), 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH), and di(2-ethylhexyl) adipate (DEHA) production have increased. However, human exposure data to these substitutes is limited, and no prior study was conducted in the Japanese population. Thus, this study aimed to examine the exposure trend of phthalate substitutes in 180 Japanese children aged 7 years old. Children were participants of the Hokkaido birth cohort and provided questionnaire data and urine samples collected from 2012–2017. Metabolites of DEHTP, DINCH, and DEHA were measured using isotope dilution LC-MS/MS.
Findings showed between 2012 and 2017 nearly a 5-fold increase in DEHTP metabolites and a 2-fold rise in DINCH metabolites. DEHA has a low detection level. None of the children exceeded the EU’s tolerable daily intake reference and Germany’s health-based guideline. A first study in the Japanese population provides valuable baseline phthalates substitute exposure. Further research is crucial to monitor these phthalate substitutes and assess the potential health impact of the exposure.

Publication Info

Exposure Trends to the Non-phthalate Plasticizers DEHTP, DINCH, and DEHA in Children from 2012 to 2017: The Hokkaido Study

Rahel Mesfin Ketemaa,b, Monika Kasper-Sonnenbergc, Yu Ait Bamaia,d, Chihiro Miyashitaa, Holger M. Kochc, Claudia Pälmkec, Reiko Kishia, Atsuko Ikedaa,b*
a Center for Environmental and Health Sciences, Hokkaido University, 060-0812, North 12, West 7, Sapporo, Japan b Faculty of Health Sciences, Hokkaido University, Japan c Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-University Bochum (IPA), Germany d Toxicological Center, University of Antwerp, Belgium *Corresponding Author

Environmental Sciences and Technology

(IF: 11.4, Category Ranking in Environmental Science: 6.9%)


・Publication date
July 28, 2023


Prof. Atsuko Ikeda (Dept. of Health Sciences and Technology)
E-mail:AAraki [at] Replace [at] with @

September 19, 2023

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