Integrated Multi-Index and Risk Assessment of Heavy Metal Pollution and Health Risks in Drinking Water of Erbil, Kurdistan–Iraq

Abstract

This study evaluated the physicochemical quality and heavy metal contamination of drinking water in Erbil City, Iraq, using an integrated multi-index and human health risk assessment approach. Thirty samples were collected from residential, commercial, and industrial zones to examine spatial variations and exposure risks. Physicochemical parameters were analyzed using standard methods, and heavy metals (Pb, As, Cd, Cr, Cu, Hg, and Fe) were quantified via atomic absorption spectrophotometry. Most parameters were within World Health Organization (WHO) limits, except for total dissolved solids (780 mg/L in Shaqlawa) and nitrate (49.4 mg/L in Baharka). Heavy metals exceeded WHO limits in several sites, particularly Pb (63.3%), Hg (53.3%), Fe (30%), and As (20%). Water Quality Index (WQI) values (52.1–124.4) indicated good to moderately polluted conditions. Heavy Metal Pollution Index (HPI) and Nemerow Pollution Index (NPI) showed localized contamination, while noncarcinogenic risk (HI > 2) and carcinogenic risk (ILCR > 1 × 10−4) highlighted significant health threats, especially for children. Arsenic contributed the highest carcinogenic burden (ILCR = 1.7 × 10−3). The findings emphasized the urgent need for improved water treatment, corrosion control, and continuous monitoring to safeguard public health in Erbil City.