Role of rice in dietary cadmium intake of farming population with no known man-made pollution in Japan.

The 24-hr duplicates of a whole day diet were collected in winter seasons from 1042 farmers in 49 non-polluted regions in Japan, and the amount of boiled rice in each duplicate was compared with the cadmium content in the duplicate to evaluate the role of rice in daily cadmium intake via food. The daily boiled rice intake (in terms of regional geometric means) varied in the range of 720-1,100 g/day for males and 300-800 g/day for females, yet positively correlated with whole day dietary cadmium intake in males (0.07 less than p less than 0.08), in females (p less than 0.01) and the combination of the two sexes (p less than 0.01). The findings, in accordance with other reports, suggest that rice is an important source of cadmium intake among Japanese population even in non-polluted areas. The roles of sake (rice wine) and beer appeared to be quite minor as the cadmium contents were very low.