Stochastic exposure and health risk assessment of rice contamination to the heavy metals in the market of Iranshahr, Iran

An investigation of some heavy metals content in rice (Oryza sativa) and associated health risks was carried out for residents of Iranshahr city, Iran. Average daily rice consumption of the citizens and most widely used rice brands in the market of Iranshahr were determined using a questionnaire. Besides, the concentration of heavy metals in the gathered rice samples was measured by inductively coupled plasma mass spectrometry (ICP-MS). Monte Carlo uncertainty simulation was utilized in conducting exposure assessment and investigating the noncarcinogenic effects of the studied elements as well as the carcinogenic effect of As. Concentrations of As, Cd, Pb, Cu, Al, and Mo were 0.369 +/- 0.094, 0.0337 +/- 0.039, 0.123 +/- 0.14, 3.095 +/- 439.42, 39.6 +/- 14.73, and 1.106 +/- 0.133 mg kg(-1), respectively. Al (0.18 +/- 0.15 mg kg(-1) d(-1)) and Cd (0.00015 +/- 0.00034 mg kg(-1) d(-1)) were the highest and lowest estimated daily intake, respectively. Except As (5.23 +/- 4.01), the calculated hazard quotient for investigated elements showed no non-carcinogenic health risk. Besides, the simulation of the carcinogenic risk effect for As (2.37E-3) revealed that the ingestion of the studied rice brands would cause cancer risk due to lifetime consumption. Results show that consumption of rice in the Iranshahr city is a potential source of exposure to the studied elements.