Levels of Polycyclic Aromatic Hydrocarbons and Heavy Metals in Surface Soil at Auto-Mechanic Workshops Within the Accra Metropolis, Ghana

ABSTRACT

This study investigated the concentrations of Polycyclic aromatic hydrocarbons (PAHs) and five selected heavy metals (Pb, Cd, Ni, Zn and Cu) in water and soil at some selected auto-mechanic shops within the Accra Metropolis. In all 57 soil samples and 36 water samples were collected between December 2015 and February 2016 from eighteen (18) selected auto-mechanic workshops, three (3) hand-dug wells and two (2) control sites. The samples were extracted and analyzed for PAHs (naphthalene, acenaphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo (a) anthracene, chrysene, benzo (b) flouranthene, benzo (k) fluoranthene, benzo (a) pyrene, indeno (1,2,3-c,d) pyrene, dibenzo (a,h) anthracene, benzo (g,h,i) perylene) and heavy metals (Pb, Cd, Ni, Zn and Cu) using the Gas chromatography equipped with combiPal autosampler and Ni electron capture detector (ECD) and the Atomic Absorption Spectroscopy (AAS) respectively. Physicochemical properties of soil and water were determined to evaluate the quality of soil and drinking water. In addition, two hundred and thirty (230) respondents (made up of 150 auto-mechanics and 80 household representatives) were randomly selected and interviewed using a structured questionnaire. Information on knowledge of chemical hazards, occupational habits, and health-related risks associated with the handling of used engine oil was sought. The results obtained showed that soil and water samples analyzed from the various sites recorded concentrations of PAHs below 0.01 µg/g and 0.01 µg/L detection limit respectively. The ranges of heavy metal concentration in water samples analyzed were: