Heavy Metals Concentration in Some Selected Dumpsites and Groundwater in Calabar, Cross River State, Nigeria

Abstract

Heavy metals concentration in soil from dumpsites and borehole water in Calabar, Nigeria was analysed. Four dumpsites: Lemna (008°21'55.912"E and 05°2'08.725"N), Nassarawa (008°21'35.168"E and 05°4'51.544"N), University of Calabar female hostel (008°20'57.937"E and 04°56'16.612"N) and Goldie market (008°20'29.34"E and 04°56'29.198"N) were selected as sampling locations while a plot of land (008°21'43.9"E and 040'58.04 227"N) was selected as a control which were labeled S1, S2, S3, S4 and PC respectively. Soil and water samples were collected for a period of twelve months following a standard procedure and analysed for heavy metals using atomic absorption spectrophotometer (AAS) while physicochemical properties of water were analysed using their respective meters. The results obtained showed that in dumpsites soil: Cadmium was the highest occurring metal with a mean concentration of 1.457±0.493 mg/kg in S4 while As in S1 was the lowest occurring metal with a concentration of 0.001 ± 0.000 mg/kg and Hg was below detection limit in all sampling locations. In water: Chromium was the highest occurring metal with a concentration of 0.006 ± 0.001 mg/l and the lowest was Cobalt and Lead with concentrations of 0.001 ± 0.000 in about all the sampling locations while Arsenic and Mercury were below detection limit in all the sampling locations. Cd, Pb and Cr in S4 soil, Cd and Cr in S4 water and TDS, electrical conductivity and hardness of water from all dumpsites were above the WHO limit while strong positive correlation was found between some heavy metals concentration in soil and water.