Source identification and health risk assessment of particle phase organic compounds in urban and rural areas of Bangladesh

¹ Department of Chemistry, Faculty of Science, University of Dhaka, Dhaka-1000, Bangladesh
² Department of Chemistry, Faculty of Science, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh

^* Corresponding author: asalam@gmail.com ; asalam@di.ac.bd

Abstract

Particle phase organic compounds (PPOCs) constitute a significant portion of suspended organic compounds in the atmosphere, impacting human health. Limited research on sources, seasonal variations, and health effects in Bangladesh motivated this study, where particulate matter samples were collected in Dhaka, Rajshahi, Narayangonj, and Bhola from January 2015 to February 2019. Sixteen PPOCs concentrations were measured using a Gas Chromatography-Mass Spectrometry (GC-MS). Average PPOC concentrations were 11.60 ± 0.1 µgm^-3 in Dhaka, 8.69 ± 0.3 µgm^-3 in Rajshahi, 11.84 ± 0.4 µgm^-3 in Narayangonj, and 7.22 ± 0.2 µgm^-3 in Bhola, with 2 to 18 times higher concentrations in winter than monsoon season. Positive Matrix Factorization (PMF) identified major PPOCs sources as diesel exhaust, biomass burning, industrial emissions, and gasoline exhaust. Urban areas were dominated by industrial emissions, while rural regions had significant biomass burning contribution. Health risk assessment indicated a hazard index (HI) of 30.2, signifying severe non-carcinogenic effects, with Dimethoate contributing significantly (32%). The average lifetime cancer risk (2.94 × 10^-3) exceeded USEPA guidelines, suggesting heightened cancer risk. Naphthalene posed the highest carcinogenic risk. Given anthropogenic sources and severe health impacts, public awareness and localized research are crucial.