Public Health

Development and Environmental Medicine

To Clarify the Association of Chemical Exposures with Child Development in Birth Cohort Studies

Medical Sciences Course

  • Master / Doctoral Degree

Faculty

SUZUKI, KichiyaSUZUKI, Kichiya
SUZUKI, Kichiya

Professor, M.D. Ph.D.

Research Theme

  • To clarify the association of prenatal chemical exposures with child neurobehavioral development in birth cohort studies
  • To examine the adverse effects of exposures to methylmercury, lead and persistent organic pollutants
  • To elucidate the environmental radioactive contamination with biomonitoring approaches after Fukushima Daiichi nuclear disaster
Research Keywords:

behavioral teratology, chemical exposure, methylmercury, risk analysis, caddisfly watch

Technical Keywords:

birth cohort study, risk determination, intelligence measurement, mental development measurement, field research in the environment

Laboratory Introduction

Several previous studies have reported the association of prenatal/perinatal exposures to environmental chemicals with poorer development in children. Especially, methylmercury (MeHg), lead, and persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs) are the chemicals that may cause delay of neurobehavioral development and behavior problems like attention deficit/hyperactivity disorder (ADHD) of children. Therefore, we have been performing two birth cohort studies; first, Tohoku Study of Child Development (TSCD) was started in 2002 at the coastal areas of Miyagi prefecture, and second, we are participating to the Japan Environment and Children’s Study (JECS) as Miyagi unit center. We are focusing on adverse effects on mental development, intelligence, laungage ability, and behavioral problems such as ADHD and autism.
Since human are exposed to MeHg and PCBs through the consumption of fishes, we pay special attention to the risk/benefit balance of fish intake. Especially, omega-3 polyunsaturated fatty acids such as DHA are considered to be beneficial to child development, while eating a lot of fishes may invite chemical exposures. Risk communication including the ongoing risk monitoring is another subject.
Additionally, after the The Great East Japan Earthquake/tsunamis, we started two field studies to examine the tsunami-induced environmental contamination by various kind of organic chemicals and to monitor the contamination of fresh water system with radioactive materials by biomonitoring using aquatic insect larvae, “caddishfly.

Figure 1. Risk and benefit balance of fish intake

Figure 1. Risk and benefit balance of fish intake

Figure 2. Prenatal exposure to PCB impaired intellectual ability in 42-month-old boys

Figure 2. Prenatal exposure to PCB impaired intellectual ability in 42-month-old boys

Recent Publications

  • Tatsuta, et al. Impacts of the Great East Japan Earthquake on Child's IQ. J Pediatr. 167(3):745-751, 2015
  • Hosaka, et al. Relationship between material gestational hypertension and home blood pressure in 7-year-old Children and their mothers: the Tohoku Study of Child Development. Hypertens Res. 38(11):776-782, 2015
  • Tatsuta N, et al. Impacts of prenatal exposures to polychlorinated biphenyls, methylmercury, and lead on intellectual ability of 42-month-old children in Japan. Environ Res. 133:321-326, 2014
  • Yoshimasu K, et al. A meta-analysis of the evidence on the impact of prenatal and early infancy exposures to mercury on autism and attention deficit/hyperactivity disorder in the childhood. Neurotoxicology. 44:121-31, 2014
  • Iwai-Shimada M, et al. Methylmercury in breast milk of Japanese mothers and lactational exposure of their infants. Chemosphere. 126:67-72, 2015