DISTRIBUTION OF HEAVY METALS CONTAMINANTS IN SURFACE SOIL, WATER, LIVER, HEART AND KIDNEY OF AMPHIBIANS PtychadenapumilioAND AmietophrynusmaculatusIN SELECTED AREAS OF LAGOS STATE.
Abstract
The increasing rate of pollution necessitates proper and effective management of environmental health by monitoring the soil, water and animal components of the environment. The study investigated distribution of selected heavy metals contaminants in soil, water samples and bioaccumulation in heart, liver and kidney of two amphibian species, Amietophrynusmaculatus and Ptychadenapumilio in selected sites such as Ibafo (bordering Lagos and Ogun States), Iwaya, Makoko 1, Makoko 2 and University of Lagos (Unilag) located in Lagos state. Heavy metals were analyzed using the Analyst 200 Perkin Elmer series of Atomic Absorption Spectrophotometer. The overall mean concentrations of the heavy metals (mg/g) in the soil samples were as follows: Fe 3.12, Cu 0.41, Ni 0.30, Cr 0.05, Cd 0.07, Pb 0.04, Zn 0.19 and Mn 0.39 thus Fe > Cu >Mn> Ni > Zn > Cd > Cr >Pb which were significantly (P < 0.05) different across the sites except for Mn, which was not significantly (P > 0.05) different (df = 4, x2 = 2.739). In water samples, the mean concentrations (mg/L) were as follows: Fe 1.80, Cu 0.74, Ni 0.78, Cr 0.06, Cd 0.05, Pb 0.03, Zn 0.54 and Mn 0.30. Zinc bioaccumulated highest in both species and in all the locations, followed by Mn and Pb.  Mn, Zn and Pb concentrated more in the liver, while Ni was highest in the heart, not significantly (P > 0.05) different in both anuran species. Cr concentration in the liver of both anuran species was significantly (P < 0.05) different (df = 8, x2 = 2.717). The study has revealed the prevailing environmental health with anurans as excellent bioindicators acting as an early warning signal of potential harm to the environment.
