Environmental evaluation of the heavy metal in urban soil and its health effects from different areas of Kirkuk governorate

Urban soil plays an important role as a source of absorption of toxic heavy metals resulting from human activities, including industrial emissions, traffic, and urban expansion. This study aims to assess the levels, sources, and risks of heavy metal contamination in the urban soil of Kirkuk. Several environmental assessments were conducted using environmental parameters. Twenty-three urban soil samples were collected at a depth of 0-15 cm and analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES). To assess contamination, indices such as the geological accumulation index (Igeo), enrichment factor (EF), contamination factor (CF), and degree of contamination (Cdeg) were calculated. The results showed that most heavy metals ranged from uncontaminated to moderately contaminated levels, with the exception of lead (Pb), which showed moderate to high contamination at specific sites. EF values indicated moderate enrichment of chromium (Cr), nickel (Ni), and lead (Pb), suggesting human impact, particularly from industrial and traffic sources. Health risk assessment showed ingestion as the primary exposure route, especially for children, with Cr posing the highest potential risk. However, most metal exposure levels were below reference doses (RfD), indicating low health risks in general. While most sites show low to moderate contamination, some require mitigation strategies due to elevated levels of lead and chromium.