Health risk assessment of heavy metals in drinking water: a case study in western cities of Mazandaran province, Iran

Industrialisation and urbanisation in the world and Iran have led to high levels of heavy metal contamination in water resources. The health risk of exposure to heavy metals via drinking water in two western cities of Mazandaran province, Iran was assessed. The concentrations of arsenic (As), chromium (Cr), and lead (Pb) in 60 water samples collected from groundwater resources of the cities of Noshahr and Ramsar were determined using inductively coupled plasma mass spectrometry (ICP-MS). The carcinogenic and non-carcinogenic health risks assessment for adults, teenagers, and children were estimated in terms of hazard quotient (HQ) and lifetime cancer risk (LTCR), 'respectively'. The average concentrations of As, Cr, and Pb in drinking water were 'respectively' 1.9, 21.6, and 1.8 mu g/L in Noshahr and 1.2, 15.6, and 1 mu g/L in Ramsar. These results showed that the concentration of metals in the studied areas were within standard ranges. The average HQs caused by exposure to Cr (0.229-0.383), As (0.200-0.333) and Pb (.016-.027) in Noshahr were lower than one. Also, the average HQ calculated due to exposure to Cr (0.151-0.253), As (0.132-0.219), and Pb (0.009-0.015) in Ramsar were within safe range. The non-carcinogenic risk of the heavy metals in Noshahr and Ramsar was in the following order: Cr > As > Pb. Based on the LTCR values, the carcinogenic risk of Cr in drinking water in the cities was higher than that of As. The LTCR values of As and Cr in drinking water for all the age groups in the cities were higher than the acceptable limit (10(-5)) recommended by the United States Environmental Protection Agency. The results can be helpful for health policy makers to prioritise interventions in the environmental health action plan and for people in taking protective measures such as using home water treatment devices.