A Review on the Abundance, Distribution and Eco-Biological Risks of PAHs in the Key Environmental Matrices of South Asia.

Polycyclic aromatic hydrocarbons (PAHs) are consistently posing high risks to human/biota in developing countries of South Asia where domestic areas are exposed to biomass burning and commercial/industrial activities. This review article summarized the available data on PAHs occurrence, distribution, potential sources and their possible risks in the key environmental matrices (i.e., Air, Soil/Sediments, Water) from South Asian Region (SAR). Available literature reviewed suggested that PAHs concentration levels were strongly influenced by the monsoonal rainfall system in the region and it has been supported by many studies that higher concentrations were measured during the winter season as compared to summer. Biomass burning (household and brick kilns activities), open burning of solid wastes and industrial and vehicular emissions were categorized as major sources of PAHs in the region. Regional comparison revealed that the contamination levels of PAHs in the water bodies and soil/sediments in SAR remained higher relatively to the reports from other regions of the world. Our findings highlight that there is still a general lack of reliable data, inventories and research studies addressing PAHs related issues in the context of environmental and human health in SAR. There is therefore a critical need to improve the current knowledge base, which should build upon the research experience from other regions which have experienced similar situations in the past. Further research into these issues in South Asia is considered vital to help inform future policies/control strategies as already successfully implemented in other countries.

Occurrence of polycyclic aromatic hydrocarbons in the Soan River, Pakistan: insights into distribution, composition, sources and ecological risk assessment.

Present study investigates the occurrence, distribution and sources of ∑17 polycyclic aromatic hydrocarbons (PAHs) in the surface water of Soan River, Pakistan. The concentrations of total PAHs ranged from 61 to 207 ng/l. Low molecular weight (LMW) PAHs were recorded higher in concentrations (64.7 percent) as compared to high molecular weight (HMW) PAHs (35.6 percent). Principal component analysis (PCA) revealed domestic and industrial wastewater discharge, vehicular exhaust, petroleum residues and biomass combustion as the main sources for PAHs contamination. Using the USEPA toxic equivalency factor (TEF) approach: Benzo(a)Pyrene and Dibenzo(a,h)Anthracene contributed highly carcinogenic exposure equivalent. The surface water of the Soan River is found to be slightly polluted with PAHs thereby posing health risks to aquatic bodies.