Statistical distribution and particle dosimetry models to estimate personal exposure at urban sidewalks of tropical climate

Abstract

Personal exposure at sidewalks along urban corridors is a topical issue which has been rarely touched upon in great detail. In the present study, statistical distribution models and particle dosimetry studies were integrated to characterize the short-term personal exposure at sidewalks along major urban corridors. The size segregated PM measurements were carried out at two contrasting urban corridors (IT corridor and beach promenade) during morning and evening peak traffic hours. The PM concentrations at IT corridor was found to be highly dependent on traffic volume and meteorology, while at beach promenade the beach activities were found to have a significant role in determining PM concentration. The PM data were fitted with the probability distribution functions (PDF) for the assessment of frequency ranges experienced by pedestrians. At both the sidewalks, the PM10 and PM2.5 mass concentrations were fitted with loglogistic-3P model while PM1 data was found to best fit to general extreme value distribution. The particle dosimetry assessment showed higher PM2.5 lung deposition in IT corridor during the morning hours (7.25 μg) as compared to the evening hours (3.6 μg). At beach promenade higher PM2.5 lung deposition was significant during the evening hours (7.14 μg) as compared to the morning hours (2.4 μg). The present method is useful for the determination of short-term peak exposures to PM at urban hotspots.