Health risk assessment of heavy metals in vegetables cultivated around Tehran Landfill area

Vegetables are one of the most critical groups in people's diet, and quality assurance plays a significant role in health and food safety. Consumption of vegetables is one of the main exposure routes for heavy metals. This study aimed to assess the carcinogenic and non-carcinogenic risks of vegetables cultivated around the Tehran landfill areas in 2019.

This descriptive study was conducted using available sampling method in 2019 on eight types of vegetables. The concentrations of heavy metals were measured using ICP-OES after acidic digestion. The carcinogenic and non-carcinogenic risks were calculated using the related equations. SPSS software was used to determine the relationships between the variables.

The results showed that the order of heavy metals concentration was Al> Fe> Zn> Mn> Cu> Ni> Pb> As> Cr> Co> Cd. The order of contamination load in different vegetables was lettuce> leek> dill> tomato> eggplant> potato> onion> cabbage. Pearson coefficient correlation showed a very strong significant relationship between Cd with Pb, Mn, and Ni at the level of 1%. Hazard quotient (HQ) and hazard index (HI) values in all vegetables were below 1, indicating no potential risk for children and adults. Lettuce, leeks, dill, tomatoes, and eggplant and lettuce, dill, and leeks had significant carcinogenic risk for children and adults, respectively.

Considering that long-term consumption of vegetables can expose the consumers to significant carcinogenic risk, mitigation measures and continuous monitoring of heavy metals in crops cultivated in the landfill areas are essential.