Heavy metal analysis and health risk assessment of particulate matter (PM₂.₅/PM₁₀) and road dust in an urban region of greater Noida, India

In this study, we assessed the health risks of particulate-bound metals arsenic (As), mercury (Hg), chromium (Cr), cobalt (Co), nickel (Ni), and zinc (Zn) in PM₂.₅, PM₁₀, and road dust samples collected from eight urban areas in Greater Noida, India. The highest concentrations were observed for As (1.40 ± 0.77 mg∙kg -1 ) and Hg (0.58 ± 0.29 mg∙kg -1 ) in road dust. The health risk assessment revealed that the non-carcinogenic hazard index (HI) values ​​were greater than 1.0 for both adults and children, suggesting potential adverse health effects. The carcinogenic risk values ​​for As, Cr, and Co exceeded the permissible limit of 1×10⁻⁴ in some samples, with the highest observed value being 3.98×10 2 for PM₁₀ exposure in adults, well above the permissible risk range (1×10⁻⁶–1×10⁻⁴). Source apportionment analysis showed that the main sources were vehicle emissions, fuel combustion, and wear of brake and tyre components. The results highlight the urgent need for regulatory action to mitigate heavy metal exposure in urban environments.