The rise in particulate matter (PM) concentrations is a serious problem for the environment. Heavy metals associated with PM₁₀, PM_2.5, and road dust adversely affect human health. Different methods have been used to assess heavy metal contamination in PM₁₀, PM_2.5, and road dust and source apportionment of these heavy metals. These assessment tools utilize pollution indices and health risk assessment models. The present study evaluates the total mass and average concentrations of heavy metals in PM₁₀, 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. 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 PM₁₀, PM_2.5, and road dust was also performed. The average mass concentration was found to be 229.54±118.40 μg m⁻³ for PM₁₀ 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 PM₁₀. The pollution load index value of PM₁₀ 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> PM₁₀> and PM_2.5. Particulate matter posed higher health risks than road dust due to particle size. The mass concentration analysis indicates serious PM₁₀ and PM_2.5 contamination in the study area. Vehicle traffic was the major source of heavy metals in PM₁₀, 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. The authors declare no competing financial interests

Regular exercise improves physiological processes and yields positive health outcomes. However, it is relatively less known that particulate matter (PM) exposure during outdoor exercises may increase several respiratory health problems depending on PM levels. In this study, the respiratory deposition doses (RDDs) in head airway (HD), tracheobronchial (TB), and alveolar (AL) regions of various PM size fractions (<10, <2.5, and <1 μm; PM₁₀, PM_2.5, and PM₁) were estimated in healthy male and female exercisers in urban outdoors and within house premises. The highest RDDs were found for PM during morning hours in winter compared with remaining periods. RDDs in AL region for males and females, respectively, were 34.7 × 10⁻² and 28.8 × 10⁻² µg min⁻¹ for PM₁₀, 65.7 × 10⁻² and 56.9 × 10⁻² µg min⁻¹ for PM_2.5, and 76.5 × 10⁻² and 66.3 × 10⁻² µg min⁻¹ for PM₁. The RDD values in AL region were significantly higher in PM₁ (27%) compared with PM_2.5 (13%) and PM₁₀ (2%) during exercise in all periods. This result showed that the morning peak hours in winter are more harmful to urban outdoor exercisers compared with other periods. This study also showed that the AL region would have been the main affected zone through fine particle (PM₁) to all the exercisers. Implications: Size-segregated particle concentrations in urban outdoors and within house premises were measured. The highest respiratory deposition doses (RDDs) were found for PM during morning hours in winter compared with remaining periods. During light exercise, the RDD values in alveolar (AL) region for PM₁₀, PM_2.5, and PM₁ for male exercisers were significantly higher, 20.4%, 15.5%, and 15.4%, respectively, compared with female exercisers during morning peak hours in winter.