Assessment of Pollution and Health Risks of Heavy Metals in Particulate Matter and Road Dust Along the Road Network of Dhanbad, India

BACKGROUND. The rise in particulate matter (PM) concentrations is a serious problem for the environment. Heavy metals associated with PM(10), PM(2.5), and road dust adversely affect human health. Different methods have been used to assess heavy metal contamination in PM(10), PM(2.5), and road dust and source apportionment of these heavy metals. These assessment tools utilize pollution indices and health risk assessment models. OBJECTIVES. The present study evaluates the total mass and average concentrations of heavy metals in PM(10), PM(2.5), and road dust along selected road networks in Dhanbad, India, analyzes the source apportionment of heavy metals, and assesses associated human health risks. METHODS. A total of 112 PM samples and 21 road dust samples were collected from six stations and one background site in Dhanbad, India from December 2015 to February 2016, and were analyzed for heavy metals (iron (Fe), lead (Pb), cadmium (Cd), nickel (Ni), copper (Cu), chromium (Cr), and zinc (Zn)) using atomic absorption spectrophotometry. Source apportionment was determined using principal component analysis. A health risk assessment of heavy metal concentrations in PM(10), PM(2.5), and road dust was also performed. RESULTS. The average mass concentration was found to be 229.54±118.40 μg m(−3) for PM(10) and 129.73 ±61.74 μg m(−3) for PM(2.5). The average concentration of heavy metals was found to be higher in PM(2.5) than PM(10). The pollution load index value of PM(10) and PM(2.5) road dust was found to be in the deteriorating category. Vehicles were the major source of pollution. The non-carcinogenic effects on children and adults were found to be within acceptable limits. The heavy metals present in PM and road dust posed a health risk in the order of road dust> PM(10)> and PM(2.5). Particulate matter posed higher health risks than road dust due to particle size. CONCLUSIONS. The mass concentration analysis indicates serious PM(10) and PM(2.5) contamination in the study area. Vehicle traffic was the major source of heavy metals in PM(10), PM(2.5), and road dust. In terms of non-carcinogenic risks posed by heavy metals in the present study, children were more affected than adults. The carcinogenic risk posed by the heavy metals was negligible. COMPETING INTERESTS. The authors declare no competing financial interests