The Concentration of Total Arsenic, Cadmium, and Lead in Imported Rice (Oryza sativa): Probabilistic Health Risk Assessment of Iranian Population

Abstract

Toxic elements, such as total arsenic (As), cadmium (Cd), and lead (Pb), can accumulate in rice (Oryza sativa), posing significant health risks to consumers. This study aimed to quantify the concentrations of As, Cd, and Pb in imported rice from India and Pakistan available in Iran and to evaluate the corresponding noncarcinogenic and carcinogenic health risks via the Monte Carlo Simulation (MCS) model. Two hundred rice samples (150 from India and 50 from Pakistan) were collected from Bandar Abbas, Iran, during 2023-2024. Samples were prepared, digested, and analyzed using graphite furnace atomic absorption spectrometry (GFAAS) to quantify the concentrations of heavy metals. Noncarcinogenic risks were estimated using the target hazard quotient (THQ) and total target hazard quotient (TTHQ). In contrast, the MCS model assessed carcinogenic risks using the incremental lifetime cancer risk (ILCR) and total incremental lifetime cancer risk (TILCR). The mean concentrations of As, Cd, and Pb in Pakistani rice were 0.112 +/- 0.035 mg/Kg, 0.041 +/- 0.010 mg/Kg, and 0.062 +/- 0.034 mg/Kg, respectively. In comparison, Indian rice exhibited lower levels at 0.077 +/- 0.042 mg/Kg, 0.019 +/- 0.012 mg/Kg, and 0.052 +/- 0.038 mg/Kg, respectively. Both types of rice had As and Cd levels below the Iranian standard limits but posed significant health risks. Noncarcinogenic risk assessments revealed TTHQ values exceeding the safety threshold (TTHQ > 1) for both adults and children, with higher risks observed in children. Carcinogenic risk assessments indicated ILCR values above the acceptable limit (1.00E-04) for As and Cd, highlighting potential long-term cancer risks, particularly for children. The findings highlight significant noncarcinogenic and carcinogenic health risks, particularly for children, underscoring the need for stricter regulatory oversight of imported rice. Public health interventions, including dietary diversification and awareness campaigns, are recommended to mitigate exposure and protect vulnerable populations.