Cadmium exposure of residents in a polluted area in Guizhou Province, China

Objective To investigate the cadmium (Cd) concentration in crops and the Cd exposure level of population in a cadmium-polluted area in Guizhou Province, China.

Methods The subjects(1 349 residents) were selected by random sampling from the local residents. A three-day survey was conducted to obtain dietary consumption. Dietary Cd content was measured by AAS, and ICP/MS was used to determine Cd in urine for estimation of internal exposure.

Results A total of 957 crop samples were collected, dietary survey was carried out for 186 residents, and testing of urine samples was conducted in 1 349 residents. The Cd content in corn, potato and rape exceeded the maximum permissible limits of food. The content of Cd in rape (mean 0.2 mg/kg) was higher than that in other foods and accounted for 50.8% of dietary Cd exposure. More than 90% of the population in the polluted area had dietary Cd exposure above the permissible limit, with a urinary Cd level of >2 μg/g in more than 90% of the population, >5 μg/g in more than 70% of the population, and >15 μg/g in around 10% of the population.

Conclusion The main dietary source of Cd is from rape and regular health screening is recommended to prevent Cd exposure from the food chain.