Japan Environment and Children's Study (JECS): Concept, Protocol and Current Status

Abstract

The Japan Environment and Children's Study (JECS) was initiated in 2011 as a national birth cohort study to investigate the environmental impact on children's health and development. JECS gives priority to five major health domains: reproduction and pregnancy complications, congenital anomalies, neuropsychiatric and developmental disorders, allergy and immune system disorders and metabolic and endocrine system dysfunctions. The environment is defined broadly as the global/ambient environment (soil, water and air), chemical substances, physical conditions, built environment, behaviors/habits, socio-economic factors and family/community support. Gene–environment interactions will also be considered. JECS has recruited 103,099 pregnant women across Japan, and their health status, exposure information and biological specimens have been collected. After birth, the main study will follow their children until they reach the age of 13years. In addition, a subcohort study, involving 5000 children randomly selected from the main study, will investigate environmental factors and outcome variables in greater detail. This will involve home visits, ambient air measurements, psychological development tests and examination by pediatricians. As of 1 June 2018, the data obtained through JECS have been reported in 24 articles published in peer-reviewed journals.