Study of pollution status and health risks for selected metals in PM₁₀ from Islamabad, Pakistan

The current study is based on the measurement and monitoring of selected trace metals in coarse particles (PM₁₀) from Islamabad, Pakistan. The particulate samples were analysed by atomic absorption spectroscopy to assess the concentration of trace metals: K, Ca, Fe, Zn, Mg, Cu, Cr, Mn, Pb, Sr, Li, Ni, Co, Ag, and Cd. The mean concentration of PM₁₀ was 88.31 µg/m³. Among the trace metals, dominant mean contribution was shown by K (3477 ng/m³), followed by Ca (1812 ng/m³), Fe (797.9 ng/m³), Zn (619.5 ng/m³), and Mg (562.6 ng/m³) with following ascending order; Cd < Li < Ag < Co < Mn < Sr < Pb < Ni < Cr < Cu < Mg < Zn < Fe < Ca < K. Multivariate analyses showed that transportation/industrial emissions, and combustion processes were the major anthropogenic emission sources of the particulates. The pollution status was evaluated in terms of enrichment factor and geoaccumulation index; the study revealed that Ag exhibited the highest contamination, followed by Cu, Zn, and Cd. Moreover, assessment of health risks for toxic metals showed that the prevailing metal concentrations were safe for non-carcinogenic risk, however, Co was the only metal that exceeded the safe limit. Toxic metals including Cr, Co, and Ni showed significant cancer risk through inhalation of the atmospheric particulates. The current elemental concentrations in PM₁₀ were compared to the previously reported levels from other regions around the globe. It was revealed that PM₁₀ levels in Islamabad exhibited relatively lower concentration than those found in Asian cities, but higher than those observed in European and American cities. Similarly, the metal levels were found to be relatively higher in the neighbouring countries.