RESUMO
The concentrations of the sixteen United States Environmental Protection Agency polycyclic aromatic hydrocarbons (PAHs) were determined in dusts from different land-use types in Benin City by means of gas chromatography-mass spectrometry. The results obtained were used to assess the ecological and human health risk and to determine the source apportionment. The Æ©16 PAH concentrations in dusts from Benin City ranged from 230 to 2300 µg kg-1 for industrial areas, 211-1330 µg kg-1 for commercial areas, 153-1170 µg kg-1 for residential areas, and from 216 to 1970 µg kg-1 for school playgrounds/parks. The ecological risk assessment suggested that the levels of PAHs in dusts from these land-use types are of low-to-moderate risk to organisms. The benzo(a)pyrene carcinogenic potency [BaPTEQ] (70.5-131 µg kg-1) and benzo(a)pyrene mutagenic potency [BaPMEQ] (62.9-122 µg kg-1) concentrations were below the Canadian soil quality guideline value of 600 µg kg-1. The incremental lifetime carcinogenic risk (ILCR) arising from exposure of adults and children to PAHs in dusts from Benin City were in the magnitude of 10-4-10-2, which exceeded the safe target levels of 10-6, implying a considerable cancer risk for residents of this city. The PAH source apportionment derived from isomeric ratios and multivariate statistics indicated that burning of biomass, wood, and charcoal, and vehicular traffic were the predominant sources of PAHs in dusts from Benin City.