Risk assessment of Cd polluted paddy soils in the industrial and township areas in Hunan, Southern China.

Cadmium (Cd) contamination in rice in Youxian, Hunan, China is a major environmental health concern. In order to reveal the Cd contamination in rice and paddy soils and the health risks to the population consuming the local rice grain, field surveys were conducted in eight towns in Youxian, China. The Cd contents of paddy soils averaged 0.228-1.91 mg kg(-1), 90% exceeding the allowable limit of 0.3 mg kg(-1) stipulated by the China Soil Environmental Quality Standards. Low average pH values (for air dried oxidized soils) ranging from 4.98 to 6.02 in paddy soil were also found. More than seventy percent (39 of 53) of the grain samples exceeded the maximum safe concentration of Cd, 0.2 mg kg(-1) on a dry weight basis. Considering the high consumption of local rice (339 g capita(-1) DW d(-1)) and Cd levels measured, dietary ingestion of 78% of the sampled rice grains would have adverse health risks because the intake exposure of Cd was greater than the JECFA recommended exposures, 0.8 µg Cd BW kg(-1) day(-1) or 25 µg Cd BW kg(-1) month(-1).