The Japan Environment and Children's Study (JECS) in Fukushima Prefecture-A progress report on the enrollment stage.

The Japan Environment and Children's Study is an ongoing nationwide birth cohort study that is being conducted at 15 regional centers throughout Japan. The recruitment of subjects in the study area within Fukushima Prefecture, which includes Fukushima City, Minami Soma City and Futaba County, was begun on January 31, 2011 with the cooperation of the obstetrics and gynecology departments of local medical institutions. On March 11, soon after the start of recruitment, the Tohoku region was hit by an unprecedented disaster in the shape of the Great East Japan Earthquake, which was closely followed by the Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Plant accident. As a result of the disaster, the study area in Fukushima Prefecture was expanded on October 1, 2012 to include 59 municipalities across Fukushima Prefecture. Three points are seen as particularly important: 1) Radiation risk communication, 2) The motto is "Be attentive. Be supportive.", and 3) Establishing cooperating partnerships. With the cooperation of all concerned, the recruitment period ended on March 31, 2014. The tentative total number of the participants enrolled at the Fukushima Regional Center was 34,666 (13,134 pregnant mothers, 8,695 fathers and 12,837 children born before November 30, 2014 as of June 2016).