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Your Environment. Your Health.

Hokkaido Birth Cohort Study on Environment and Children's Health (Sapporo Cohort)

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Centre Hokkaido University
Reiko Kishi, M.D., Ph.D.
Professor and Deputy Director
Hokkaido University Center for Environmental and Health Sciences
Description of cohort 514 Japanese women were recruited at 23-35 weeks of pregnancy from one obstetric hospital and children were followed until puberty. This is part of an ongoing cohort study to examine the potential negative effects of perinatal environmental chemical exposures on birth outcomes, neurodevelopment, and allergy, and to identify individuals genetically susceptible to environmental chemicals.
Website link
Location of cohort Sapporo, Japan
Chemicals/Exposures studied Chlorinated compounds (PCB, dioxins, PCDD, PCDF ), perfluorinated compounds (PFOS, PFOA), phthalate metabolites, chlorinated pesticides, BPA, cotinine, methyl mercury
Health or social effects studied Reduced birth size, growth, neurodevelopment, IQ, allergy, infectious diseases, imbalance of thyroid hormones and reproductive hormones
Samples collected Maternal and cord blood, milk, hair
Questionnaires Yes; baseline questionnaire during pregnancy, medical birth record, follow up questionnaires
Key Findings “We conducted a congener-specific analysis of non-dioxin like PCBs and among 197 congeners, 58 were identified in the blood of pregnant women. The concentration of toxic equivalents (TEQ) of dioxin and other specific congeners of PCDF or PCDD showed association with reduced birth weight, impaired neurodevelopment, and reduced immune function. PFOS levels negatively associated with birth weight of female infants (but not male infants). PFOA levels did not correlate with birth weight in both sexes. We observed a significant association between high maternal PFOA levels and decreased cord blood IgE levels in female infants.  Low birth size in relation to maternal smoking and genetic polymorphisms was found suggest an important modulating role for polymorphisms in metabolizing enzyme genes in concert with adverse effects of maternal smoking on infant birth size.”

Kishi R, Sasaki S, Yoshioka E, Yuasa M, Sata F, Saijo Y, Kurahashi N, Tamaki J, Endo T, Sengoku K, Nonomura K, Minakami H: Cohort Profile: The Hokkaido Study on Environment and Children’s Health in Japan. Int J Epidemiol 2011, 40:611-618. [Abstract]

Kishi R, Kobayashi S, Ikeno T, Araki A, Miyashita C, Itoh S, Sasaki S, Okada E, Kobayashi S, Kashino I, Itoh K, Nakajima S, The members of the Hokkaido Study on Environment Children’s H: Ten years of progress in the Hokkaido birth cohort study on environment and children’s health: cohort profile-updated 2013. Environ Health Prev Med 2013, 18:429-450. [Abstract]
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