Monitoring of atmospheric polycyclic aromatic hydrocarbons by polyurethane foam-passive air samplers in Bangladesh: Source apportionment and health risk assessment

Bangladesh is one of the most populated countries in the world. Rapid industrialization and urbanization in the last decades have caused emission of pollutants in the environment. The aim of the study was to assess atmospheric 16 polycyclic aromatic hydrocarbons (Σ16PAH) in Bangladesh using PUF-PASs deployed in 5 metropolitan cities and one large non-metropolitan city from December 2017 to September 2018. Spatial distribution of Σ16PAH ranged from 3.6 ± 1.1 to 22.4 ± 6.9 ng/m3. The maximum concentration of 22.4 ± 6.69 ng/m3 was found on the site-23 (urban), a newly established metropolitan city. Reasonably, the lowest concentration (3.6 ± 1.1 ng/m3) was recorded at the rural site (site-7). Seasonal variation of ∑16PAH was found to be 4.8–28.4, 2.2–12.0 and 2.7–30.5 ng/m3 in the winter, pre-monsoon and monsoon, respectively. Among the PAH isomers, phenanthrene, fluoranthene and pyrene significantly contributed to the total concentrations of PAHs with 30.4, 27.8 and 20.1% in the winter, 18.9, 29.4 and 21.9% in pre-monsoon and 14.2, 29.9 and 21.9% in monsoon, respectively. Seasonal variation of PAHs followed the decreasing order: winter > monsoon > pre-monsoon. Molecular weight-based results revealed that 4- and 3-rings PAHs (4-rings: 53–60%; 3-rings: 23–37%) mostly contributed to the total concentration of PAHs. Diagnostic ratios, PMF model and PCA results suggested that combustion of coal, petroleum, and incineration of biomass/plastics and municipal solid waste are the primary sources of PAHs in Bangladesh. Calculated BaPTEQ and BaPMEQ and ICR values were higher for the children than that of the adults. The higher values of the BaPTEQ and BaPMEQ and ICR compared to those suggested by the WHO and USEPA, imply that population of Bangladesh, particularly children, may be at high risk for health problems from PAHs.