monitoring and risk characteristics of heavy metals in agricultural products in qom, iran

Considering the high consumption of agricultural and greenhouse fruits in the city of qom, and the lack of study records, this research for monitoring of heavy metals in agricultural and greenhouse products and conduct of human health risk assessment was carried . this study was designed and conducted in two stage. in the first stage, two categories’ of agricultural products including vegetables (lettuce, tomatoes, onion and potatoes) and greenhouse products (cucumbers, tomato, bell pepper) were selected and after sample preparation and extraction, the amounts of heavy metals was measured with the atomic absorption device. in the second stage, exposure risk assessment of heavy metals (pb, cd, cr, hg, and as) were investigated. the finding of the research revealed that the measured concentrations of heavy metals in agricultural products as well as greenhouse products compared to the maximum allowed values of heavy metals in agricultural products in the iranian standards institute are higher in 35% of the evaluated samples. health risk assessment results of this study indicated that hazard index (hi) for agricultural and greenhouse products is lower than 1(hi ˂1), therefore, it is estimated that the non-cancer risk of consuming these products is negligible according to the exposure pattern and consumption level. moreover, the cancer risk (σ cr) calculated for age groups of childhood (1-6) by consumption of onion, tomato and lettuce products was higher than the estimated acceptable limits (the acceptable level of 1 case per 100000). considering the wide trend of using agricultural products in iran and especially in the city of qom, as well as the risk of carcinogenesis is higher than the acceptable limits, continuous monitoring of heavy metal levels in products as well as in water and soil resources used in crop cultivation is inevitable.