TABLE 1 

Summary of sample groups and sites

GroupAge (yr)No. female, maleSampling location
Children
    Kindergarten3–660, 43Dagang Central Kindergarten, Zhenjiang City, Jiangsu Province;
Taicang Weiyang Kindergarten, Suzhou City, Jiangsu Province;
Taicang Huasheng Kindergarten, Suzhou City, Jiangsu Province
    Primary school8–1290, 71Dagang Central Primary School, Zhenjiang City, Jiangsu Province;
Taicang Zhu Diwen Primary School, Suzhou City, Jiangsu Province
    Middle school13–1465, 49Taicang No. 2 Middle School, Suzhou City, Jiangsu Province
Adults
    Youth19–2455, 80Taicang Chien-Shiung Institute of Technology, Suzhou City,
Jiangsu Province
    Middle age30–5066, 20Taicang Xingda Can Co., Ltd., Suzhou City, Jiangsu Province
    Elderly60–7943, 43Taicang Xinhu Community, Suzhou City, Jiangsu Province
    Centenarians>94142, 56RuGao City, Nantong City, Jiangsu Province
    Young soldiers19–2412, 200Gansu police detachment training base and
PLA training base in Lanzhou, Gansu Province