Occurrence and exposure assessment of chlorate and perchlorate in food and drinking water from Fujian, China

Exposure to chlorate and perchlorate can cause significant health problems because of the sustained inhibition of iodine uptake by the thyroid. This study analyzed the contamination characteristics of chlorate and perchlorate in food and drinking water and assessed the exposure of the population in Fujian, China. A total of 679 samples, including 661 food samples belonging to 14 types and 18 drinking water samples, were analyzed by modified liquid chromatography–tandem mass spectrometry. The detection rates of chlorate and perchlorate in food was 38.8% and 90.6%, respectively, and the detection rates of chlorate and perchlorate in drinking water was 100%. The maximum concentration of chlorate and perchlorate in food was 2480 μg/kg of Agaricus blazei Murill and 4550 μg/kg of Chinese prickly ash, whereas the maximum concentration in drinking water was 83.3 and 5.67 μg/kg, respectively. The mean dietary exposure to chlorate and perchlorate for infants was below the tolerable daily intake recommended by EFSA. The average daily dose of chlorate and perchlorate for infants was 15.6 and 1.06 μg/kg, respectively, with drinking water and infant formula being the main routes of exposure. The average daily dose of chlorate in adults was 4.31 μg/kg, with drinking water, edible fungi, meat, vegetables, and milk being the main exposure routes. The mean dietary exposure and average daily dose of perchlorate for adults were 0.440 and 2.49 μg/kg, respectively, with cereals, spices, vegetables, marine fish, eggs, and milk being the main routes of exposure. Therefore, risk reduction and regulation are necessary.