Assessment of Heavy Metal Contamination in Drinking Water Sources

Drinking water quality monitoring is important where aging distribution infrastructure and reliance on bottled water may affect consumer exposure. This study assessed physicochemical parameters, three metals, and modeled non-carcinogenic hazards in 7 drinking-water sources in Kirkuk, Iraq, comprising 7 municipal tap-water sources (W1-W7). Cadmium, nickel, and zinc were measured using a Shimadzu AA-7000 flame atomic absorption spectrometer. The reported physicochemical measurements were within the comparison ranges presented in the manuscript. Zinc ranged from 0.0009 to 0.1324 mg/L, and all the other samples were under the 3 mg/L comparison value. Cadmium exceeded 0.003 mg/L in 4 of seven (57.1 %). Nickel ranged from 0.00 to 0.0388 mg/L, two samples exceeded the Iraqi comparison value of 0.02 mg/L While none exceeded the WHO value of 0.07 mg/L. Under the study’s stated screening assumptions, hazard indices exceeded one at two sources for adults and three sources for children. The highest calculated child hazard index was approximately 4.26 at Al-Iskan (W3). These results identify potential exposure concerns in the sampled sources. The modeled risks remain conditional on the selected toxicity benchmarks. The measurements do not establish the origins of contamination or demonstrate clinical health effects.‎