Indoor Air Quality Assessment. A Pilot Study at the University of Ghana

Abstract

Polycyclic Aromatic Hydrocarbons (PAHs) are a class of unique carcinogenic and mutagenic pollutants and are the byproducts of incomplete combustion of organic materials such as fossil fuels, wood and tobacco. PAHs are distributed in the environment (i.e. air, soil and water). The health effects of PAHs are driven by exposure. Assessment of human exposure to PAHs in ambient air can be accomplished by monitoring the concentration of PAHs in the environment. The concentrations and compositional patterns of the 16 PAHs prioritized by US Environmental Protection Agency (EPA) were determined in organic film on glass window surfaces in different buildings on University of Ghana (UG) campus with the view of providing the information on the extent of contamination, sources of pollution and human health risk of PAHs in the organic film. The analyses were performed by means of GC-MS after soxhlex extraction with hexane and acetone (1:1). The concentration levels of the 16 USEPA PAHs in the organic film ranged from 126.8μg/kg to 628.8μg/kg with a mean value of 336 ± 190 μg/kg. A concentration gradient of the total PAHs was observed as follows; African Studies Department Library˃ Jones Quartey˃ Sarbah Dining Hall˃ Balme Library˃ Central Cafeteria˃ University of Ghana Basic School> Chemistry Lower Lecture Theater. The distribution was characterized by 2-4 rings PAHs contributing about 82% of the total PAHs in the studied area. Assessment of their sources using diagnostic ratio showed that emission of PAHs was mostly from fossil fuel combustion. The Σ8PAH (carcinogenic) concentration ranged from 38.9μg/kg to 75μg/kg. The estimated BaPeq (Cancer Risk Level) varied from 13.0μg/kg to 17.7μg/kg. The results show low BaPeq as compared to 600μg/kg which according to Canadian ministry of Ecology corresponds to a carcinogenic risk for persons (based on an incremental lifetime cancer risk (ILCR) of 10-6).