Urban-rural comparison on cadmium exposure among general populations in Shandong Province, China.

In 1996, peripheral blood samples and 24-h food duplicate samples together with samples of wheat, rice, foxtail millet and maize were collected from 50 non-smoking women each from Jinan (a provincial capital) and Baiquan (a nearby basically self-sustaining farming village) in China. The samples were analyzed for cadmium (Cd) contents by graphite furnace atomic absorption spectrometry after wet digestion. The dietary Cd intake of the people in the city was 6.4 micrograms/day as a geometric mean (GM) and 5.9 micrograms/day for the villagers. The Cd level in blood was 0.48 and 0.29micrograms/l (as GMs) for the city and village people, respectively. Thus, Cd burden of the people in the city tended to be greater than that for those in the village. Nevertheless, the Cd burden of the Jinan citizens was lower than the values published for people in large cities in China. When Cd intake via the four cereals was compared with Cd in total food to estimate the total contribution of the four cereals (combined) in total dietary Cd intake, the cereals accounted for 60% of total dietary Cd intake among the city people and as high as 78% among the villagers. Cadmium contents in the four cereals were in a narrow range and it was considered acceptable to combine all cereals in evaluating them as dietary Cd sources.