Dietary cadmium exposure assessment in rural areas of Southwest China

Dietary exposure of cadmium (Cd) has not been studied in Southwest China.The objective of the study was to determine the pollution characteristics and contamination levels in various agriculture products in Southwest China and to conduct a comparison of dietary exposure assessment of Cd in polluted and non-polluted areas.Results showed that the mean Cd contents in rice were 0.53 and 0.52 mg/kg in the high-polluted and low-polluted areas, respectively, with the average value was 0.03 mg/kg in the control area.The mean dietary Cd exposure from rice and vegetables of the selected non-occupational residents in Southwest China was 113.10 μg/kg bodyweight (bw)/month, 88.80 μg/kg bw/month, and 16.50 μg/kg bw/month in the high-polluted, low-polluted, and control areas, respectively, which correspond to 4.5 times, 3.6 times, and 0.66 times of the provisional tolerable monthly intake (25 μg/kg bw/month) established by the Joint FAO/WHO Expert Committee on Food Additives.The findings indicated that the risk for Cd exposure of residents was high due to home-grown food (most especially rice) being near polluted areas and is of great concern. Background and introductionHuman exposure to heavy metals is one of the most significant risk factors and has been the subject of numerous scientific studies, with cadmium (hereafter Cd) being the most frequently investigated.Currently, the most convincing adverse effects of long-term Cd exposure are kidney injury [1], bone damage, and cancer [2].The Joint FAO/WHO Expert Committee on Food Additives (JECFA) established a provisional tolerable monthly intake (PTMI) level of 25 μg/kg bodyweight (bw)/month [3].Cd-contaminated food is the major source of Cd for the non-occupationally exposed population [4].Cd is a toxicant with high rates of soil-to-plant transference.Edible plants grown on contaminated soils have been proved to be an important health concern due to the high content of Cd [5,6].Cd levels in agricultural products vary widely, depending on plant varieties, soil types, and growing conditions [7,8].Foods that are frequently consumed in large quantities, such as rice, wheat, cereal crops, and leafy vegetables, could be the most significant dietary