Size-segregated particulate matter and its association with respiratory deposition doses among outdoor exercisers in Dhanbad City, India

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 mu m; PM10, PM2.5, 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 x 10(-2) and 28.8 x 10(-2) mu g min(-1) for PM10, 65.7 x 10(-2) and 56.9 x 10(-2) mu g min(-1) for PM2.5, and 76.5 x 10(-2) and 66.3 x 10(-2) mu g min(-1) for PM1. The RDD values in AL region were significantly higher in PM1 (27%) compared with PM2.5 (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, PM2.5, 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.