Shinshu University undertakes study into link between prenatal exposure to organic fluorine compounds and child asthma symptoms at 4 years of age

A research team led by Professor Tetsuo Nomiyama and Assistant Professor Kohei Hasegawa of the Japan Environment and Children's Study (JECS) Koshin Unit Center at Shinshu University examined the association between maternal blood levels of organic fluorine compounds (per- and polyfluoroalkyl substances [PFAS]) during pregnancy and the prevalence of child wheezing and asthma symptoms at 4 years of age in approximately 18,000 mother-child pairs in the JECS. On December 12, 2023, the research team announced no apparent association. The study results were published in Environmental Research.

The JECS is a nationwide large-scale birth cohort survey study of child health and environment. It has been performed longitudinally on approximately 100,000 mother-child pairs across Japan by the Ministry of the Environment since 2010.

One risk factor for asthma, which is among the most common diseases in children, involves the exposure to chemicals during gestation and early life. Organic fluorine compounds (PFAS) affect the immune system.

Among approximately 100,000 mother-child pairs participating in the JECS, data of approximately 25,000 pairs whose maternal blood levels of PFAS during pregnancy had been measured were compiled in the present study. Of them, it used data from 17,856 pairs that contains a complete set of data required for the analysis.

Data on the prevalence of child wheezing and asthma symptoms at 4 years of age were obtained from the questionnaire. Six types of PFAS were analyzed.

A logistic regression analysis was performed to examine the association between maternal blood PFAS levels during pregnancy and the prevalence of child wheezing and asthma symptoms. It considered the effect of factors potentially related to the prevalence of child asthma symptoms (maternal age, body mass index, asthma history, education, smoking history, household income, and parity).

No definite association was found between maternal blood PFAS levels during pregnancy and the prevalence of child wheezing and asthma symptoms, nor were there apparent differences in the associations by child sex or maternal asthma history. Regional heterogeneity was observed in the associations. Further research is needed to investigate the long-term impacts of PFAS exposure during gestation.

Journal Information
Publication: Environmental Research
Title: Associations between prenatal exposure to per- and polyfluoroalkyl substances and wheezing and asthma symptoms in 4-year-old children: The Japan Environment and Children's Study
DOI: 10.1016/j.envres.2023.117499