Evaluation of heavy metal contamination and associated health risk assessment in water body of the Jajrood River, Iran

The purpose of the present study is to assess the water quality of Jajrood River as one of the key drinking water resources of Tehran, Iran. Heavy metal contamination of the river is one of the major environmental concerns because of toxic effects, longterm persistence, and accumulation capacity of heavy metals in aquatic environment. The concentrations of Cr, Co, Cd, Pb, Cu, Zn, Al, Mg, Sn, Se, and Ba as well as related temporal variations were determined by collecting 784 samples from eight hydrometric stations between spring 2016 and winter 2017. Observations indicated that the Al had the highest mean concentration (0.49353 ppm), which is more than allowable limit, while the concentration of other heavy metals was within the acceptable range. The highest Average Daily Dose (ADD) value (41.361 μg/kg day) was obtained for summer while the lowest value (0.003 μg/kg day) for spring. It was found that Heavy Metal Pollution Index (HPI) values at all stations for four seasons ranged from 10.31 to 21.55 ppm. Moreover, obtained results showed that Hazard Quotient (HQ) values of studied heavy metals were below allowable limit ( 1). The results also indicated that further attention should be paid to adjust the high concentration of Al since its presence in drinking water supplies can lead to several health problems for residents of Tehran.