Health Risk of Rainwater in Erbil, Kurdistan-Iraq: Atmospheric Deposition and Public Health Implication.

This study investigated the chemical properties and concentrations of major pollutants, including toxic elements, across four zones of Erbil City: city center, industrial, residential, and suburban areas, with samples collected from five sub-sites in each zone. The pH, electrical conductivity (EC), total dissolved solids (TDS), nitrate (NO3), sulfate (SO4), ammonium (NH4) and major toxic elements including chromium (Cr), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) were analyzed. In the study area, the pH values ranged from 5.1 to 6.7 with industrial sites revealing slightly acidic conditions (5.1-5.3). Industrial zones revealed elevated EC (> 690 μS/cm) and TDS (> 500 mg/L), alongside high NO3 concentrations (7.5 to 8.1 mg/L). Heavy metal analysis revealed that heavy metal concentrations were highest in industrial areas, with Pb reaching 48.0 μg/L, Cd 2.1 μg/L, Cr 4.5 μg/L, and As 3.60 μg/L, which were higher than WHO guidelines. While in residential areas, NH4 levels were (> 0.32 ± 0.02 mg/L). Sulfate concentrations varied between 0.50 and 2.0 mg/L, with industrial sites showing the highest values, and concentrations increased. The results demonstrated that the city center and residential areas showed moderate contamination, while suburban areas demonstrated the lowest pollutant concentrations and revealed minimal anthropogenic influence. The study demonstrated that around 70% of samples posed moderate to high noncarcinogenic risks for children in the studied sites.