A review on the cadmium content of rice, daily cadmium intake, and accumulation in the kidneys

The body burden of cadmium primarily depends on the daily intake of the element in food, and thus the geographical differences in cadmium content in foods and the daily intake of cadmium should be studied. There is a food chain from soil through plant and animal foods to man. Estimation of daily cadmium intake according to the geographical region is important for monitoring environmental cadmium pollution and health effects. In the 1990s, the daily intake of cadmium and accumulation in the kidney were reported. Japanese have a relatively high daily intake of cadmium, although the percentage daily cadmium intake obtained from rice decreased from 50% in 1970 to 34% in 1994. This change is proportional to the change in average rice consumption from 261 g/day in 1970 to 182 g/day in 1994. These changes also indicate a reduced cadmium burden in the past twenty years, from 35-50 mu g/day to 30 mu g/day. The cadmium level in the renal cortex of Japanese is the highest in the world, but the cadmium in the kidney has been decreasing in most Japanese.