Distribution and health risk assessment of Benzo[a]pyrene in street dust of Raniganj in Eastern India

Abstract

This study investigates the seasonal and spatial distribution of Benzo[a]pyrene (BaP) in street dust across Raniganj, revealing significant variations linked to both seasonal shifts and land use types. BaP concentrations in street dust samples ranged from 82.2 ng/g to 531.6 ng/g with a mean value of 262.45±75.55 ng/g. The highest BaP levels were observed during winter, particularly in busy traffic, coal mines and industrial areas, suggesting contributions from industrial activities and vehicular emissions, coal chemical production and gangue accumulation. An analysis by land use type indicated that BaP levels were highest in busy traffic areas, coal mine areas and industrial areas, with traffic-congested sites showing the highest average concentration (328.29 ng/g). Seasonal analysis showed winter BaP concentrations were the highest on average (336.28±93.43 ng/g), followed by monsoon and summer. These seasonal differences may be due to winter-specific factors like increased vehicular traffic, indoor heating, and atmospheric stability. In all five sampling locations, the hazard index (HI) values show moderate levels for both adults and children. Adults had an average overall cancer risk value of 2.89E-03, while children had an average of 2.61E-03 indicating both age groups are under high risk. Samples collected from various land use types revealed a distinct difference in mean total BaP levels, as well as total cancer risk levels, with the following order, observed: busy traffic area > coal mine area > industrial area > commercial area > residential area. The findings underscore the impact of anthropogenic activities and seasonal changes on BaP levels, emphasizing the need for targeted pollution management strategies in busy traffic and industrial regions along with coal mining regions of Raniganj.