Risk assessment of zinc and copper exposure in rice, wheat and soil around Irankooh mine in Isfahan

Zinc (Zn) and Copper (Cu) are essential micronutrients for human health but elevated heavy metal uptake is the etiology of a number of diseases in the human body.S o, it is necessary to investigate the copper and zinc concentrations in agricultural products and their effects on human health. The purpose of this study was to determine the Zn and Cu concentrations in food products and the risk assessment of these elements on human health for non-carcinogenic diseases around Irankooh mine in Isfahan province, Iran.
The crop (rice and wheat) samples were obtained in ten different fields for each investigated crop and then three composite samples of the edible portion of the mentioned crops were collected. In addition, three composite surface soil samples were taken from the fields (rice and wheat) in each sampling points.
The total concentration of Cu and Zn were 28.62 mg kg−1 and 269.78 mg kg−1 in soil samples, respectively. The mean concentrations of Cu were 11.84 and 8.43 mg kg−1 in rice and wheat respectively. Also, the mean concentrations of Zn were 92.82 and 29.06 mg kg−1 in rice and wheat respectively. The Cu and Zn concentrations in soils and plants decreased in the order of distance from the mine. The dietary intakes of Zn and Cu are estimated respectively as 214.43 and 34.05 µg kg−1day−1 for adults, and 199.6 and 32.17 µg kg−1 day−1 for children. These values were lower than the WHO levels for human consumption which are 40 and 300 µg kg−1day-1 for Cu and Zn, respectively. The estimated dermal absorbed doses for RME (Reasonable Maximum Exposure) scenarios of Cu through soil exposure were 9.44×10-4 and 1.03×10-4 µg kg-1 day-1 for children and adults, respectively. These values for Zn were 8.9×10-3 and 9.84×10-4 µg kg-1 day-1 for children and adults, respectively. The estimated particulate inhalation values for RME exposure scenarios of Cu were 1.4×10-5 and 7.6×10-6 µg kg-1 day-1 for children and adults, respectively. These values were 1.32×10-4 and 7.19×10-5 µg kg-1 day-1 for Zn. These values were less than the absorbed reference dose of 0.4 and 3 μg kg−1 day−1 for Cu and Zn, respectively.
The hazard quotients (HQ) of individual zinc and copper were less than one. The results showed that there are not any non-carcinogenic health effects through these routes for consumers in the region.