Environmental occurrence and health risk assessment of arsenic in Iran: a systematic review and Meta-analysis

ABSTRACT Arsenic concentrations in different environmental media (water, soil/sediment, food) in Iran from studies performed 2008-2019 were analyzed, and health risk assessment was conducted to depict the arsenic pollution situation at the national scale. Seventy-one studies comprising 5,007 samples were included in the meta-analysis. The weighted concentrations of arsenic in ‘drinking water/water resources’, ‘soil/sediment’ and ‘Iranian rice/imported rice’ subgroups were ‘9.36, 39.2 µg/L’; ‘8.38, 14.9 mg/kg’ and ‘0.06, 0.112 mg/kg’, respectively. The weighted mean value for arsenic concentration in drinking water group was near the World Health Organization (WHO) permissible limit (10 μg/L). Mainly, geogenic sources were introduced as the most common sources of high arsenic manifestation in water resources. Regarding the soil and sediment, the maximum mean concentrations recorded in the vicinity of the mining areas (1700 mg/kg and 161 mg/kg, respectively). The average arsenic exposure from imported rice consumption was approximately 2 times higher than Iranian rice; however, the amount of lifetime cancer risk (LTCR) related to arsenic in both rice types was more than 1.0 × 10-4, indicating that consumers in Iran are at threshold carcinogenic risk of arsenic. The lowest and highest values of LTCR were observed at 9.52 × 10−6 for ‘soil’ and 7.52 × 10−4 for ‘water resources’, respectively. It is concluded that part of the Iranian population in specific regions may carry a relatively high risk, while others have a low risk.