Potentially harmful heavy metal contamination in Babolrood river: evaluation for risk assessment in the Mazandaran province, Iran

Rivers,as the kind of freshwater resources throughout the world, play a key role in the lives of living things. Heavy metal contamination of river water is primarily attributed to human activities, and there is anincreasing need to conduct risk assessments to characterise the nature and magnitude ofrisks to humans and ecological receptors from these contaminants.The PG990 nuclear absorption spectrophotometer measured concentrations of heavy metals. Trace metals (Cd, Pb, Ni, Zn) in Babolrood river from the Babol region of North Iran were analysed to assess pollution using the Hazard Quotients (HQ), Hazard Index (HI) and the Incremental Lifetime Cancer Risk (ILCR).The Environmental Protection Agency (EPA) model was applied to calculate human health risk (HHR). Heavy metal concentration varied considerably Cd (0.004 to 89.287 µg/L), Ni (0.89–49.78 µg/L), Pb (3.4–181.75 µg/L) and Ni (0.0–243.3 µg/L). The oral Hazard quotients (HQ) values for Pb were ranged from 1.04–7.83 µg/L, therefore indicated in all sampled stations HQ values above 1 for children group. In contrast, the oral and dermal HQ values for both groups were less than 1 for Zn and Ni in all sampling stations. The Hazard Index (HI) values demonstrate that total HI values were above 1 for children group in water samples of all stations. Generally, total HI values for children were much higher than that of adults among Babolrood River. The Excess Lifetime Cancer Risk (ELCR) values for Cd and Pb in all sample stations for children were higher than the EPA risk assessment guideline limit (10−6-10−4).