Exposure risk assessment of polycyclic aromatic Hydrocarbons associated with the indoor air particulate Matters in selected indoor environments in Kandy, Sri Lanka

The present work investigates the health risks associated with the inhalation exposure of particulate bound polyaromatic hydrocarbons in selected indoor environment in Kandy city. Particulate samples from five different types of indoor environments were collected for chemical analysis of 16PAH priority pollutants listed by USEPA. Categorization of locations was based on the degree of urbanization, type of fuel used for cooking and proximity to road from the location. Key meteorological parameters such as wind speed, wind direction, ambient temperature and relative humidity were also measured. The collected samples were analysed using a high performance liquid chromatograph (HPLC), after the necessary extraction and cleaning up of the sample. The total concentrations of particulate PAHs are in the range of 0.386 ng/m3 to 14.65 ng/m3. The comparison of PAH levels at different categories of environment indicate that the degree of urbanization, fuel type and proximity to road influences the total concentrations of particulate PAHs. The dominant particulates of PAHs measured at the selected environments are naphthalene, acenaphthylene, acenaphthene. Then benzo[a]pyrene [B(a)P] indicating particulate PAHs are contributed by a mixture of both diesel and petrol engine type of vehicles, and biomass combustion. The total BaPeq concentrations at different environmental categories ranged from 0.06 to 3.08 ng/m3. The total BaP equivalency results showed the potential health risk to cancer due to inhalation exposure is of concern for residents living in high urban area with usage of wood as fuel. Since the total BaPeq concentrations for this category was higher. Very close to, or slightly exceeded the maximum permissible risk level of 1 ng/m3 of benzo(a)pyrene in other categories also