Jornal de Biorremediação e Biodegradação

Abstrato

Heavy Metals and Polycyclic Aromatic Hydrocarbon Contents of Soil and Selected Vegetable from Waste Disposal Sites in Rivers State

Uchenna C Ileagu, Wegwu Matthew Owhondah, Essien Eka Bassey

This experiment was designed to evaluate the levels of heavy metals and polycyclic aromatic hydrocarbons in edible vegetables grown around dumpsites and are consumed by people living within the communities. The concentration of heavy metals and PAHs in soils and vegetables from five waste disposal sites in Rivers State were investigated using standard analytical procedures. End determination of the heavy metals and PAHs was achieved with a flame type atomic absorption spectrophotometer (AAS), and Gas chromatography flame ionization detector (GC-FID) respectively. Some results obtained from the soil sample show the range of various heavy metals included Pb, 3.55-6.14 mg/kg; As, 0.425-2.43 mg/kg; Cr, 4.07-9.79 mg/kg and Zn, 3.34-9.05 mg/kg. The results from the Talinum triangulare leaf sample show the range of various heavy metals-Pb, 0.33-1.55 mg/kg; As, 0.308-0.618 mg/kg; Cr, 0.038-0.072 mg/kg; Zn, 4.118-11.242 mg/kg; Co, 0.301-0.520 mg/kg; and Cu, 2.862-7.242 mg/kg. All the concentration of the 16 PAHs obtained from the analysis had relatively lower concentrations than the maximum allowable concentration. Their control samples showed no trace of PAHs in both the soil and leaf samples. Among the analysed PAHs, there was a predominance of phenanthrene (0.842 mg/kg) for soil and (0.58 mg/kg) for the vegetable, which was above the maximum limit of 0.14 mg/kg and can pose serious health risks to consumers of these dumpsite vegetables. Treatment of industrial effluents and phyto-extraction of excess metals from polluted environments could reduce health risk. Also recommendations on the proper handling of wastes to reduce possible toxic metal and PAH loads at dumpsites have also been highlighted.