Emission sources and full spectrum of health impacts of black carbon associated polycyclic aromatic hydrocarbons (PAHs) in urban environment: A review

With increased urbanization and industrialization, the global burden of anthropogenic emissions through biomass and fossil fuel combustion has increased significantly, threatening the global climate system, air quality and human health. Half of the aerosol particles emitted as a result of combustion are in the form of black carbon (BC), co-emitted with polycyclic aromatic hydrocarbons (PAHs). Due to strong sorption efficiency, BC act as a carrier for highly toxic and carcinogenic PAHs in air, water and soil, causing serious health issues. Scientific literature shows that the global burden of diseases has increased due to the high pollution levels of these pollutants in the environment. BC in association with PAHs can pose acute and chronic health problems such as respiratory problems, acute bronchitis, heart problems, lung cancer, aggravation of preexisting heart and lung disease, and asthma. In addition, most of the PAHs released into the environment, due to combustion activities, are categorized as type 2A or 2B human carcinogens by US EPA. In light of environmental significance of BC associated PAHs, this article stipulated a critical overview regarding the properties, pollution sources and worldwide pollution status of BC and associated PAHs along with the health risk these pollutants can pose.