| Popis: |
Polycyclic aromatic hydrocarbons (PAHs), heavy metals (Ni, Mn, Zn, Pb, and Cd) in biota and water and Physico-chemical parameters [pH, temperature, oxidation-reduction potential (ORP), dissolved oxygen (DO), biological oxygen demand (BOD), alkalinity, sulphate, electrical conductivity, turbidity, salinity, chloride, phosphate, nitrate, sulphate, calcium, magnesium and water hardness] in water were measured in an oil drilling waste polluted freshwater swamp in the Mgbede Oil Fields of South-south Nigeria. Results showed that most of the parameters in the water column were within safe limits for biota except chromium, zinc, DO and PO4 3- that had concentrations that can trigger eutrophication and where acute and chronic impacts on biota could occur. All other contaminants had concentrations that could engender health problems. Cadmium concentrations ranged between 1.0-8.64; chromium (2.17-34.22), lead (1.29-9.07), nickel (2.53-12.7), zinc( 0.88-44.44), while PAH concentration was 0.0055 ppm in water and ranged between Pb>Ni>Cr>Zn) followed by the water lettuce (Ni>Cr>Cd>Zn>Pb), snail shell (Zn>Cd>Pb>Cr>Ni) and water [(Cd,Pb)>Ni>Cr>Zn]. Polycyclic aromatics also occurred at various cancer risk levels (10-5 in epiplatys and 10-6 in water lettuce and water snail). An official ban on the consumption of fish from this swamp and immediate remediation of the swamp are recommended. |
