Heavy Metals Concentration and Arthropod Population in Some Selected Dumpsites from Calabar, Cross River State, Nigeria

Abstract

The aim of this research is to investigate the influence of refuse dumping on arthropods population and heavy metals concentration in Calabar Cross River state, Nigeria. Soil, and arthropod samples were collected from Lemna, Nassarawa, University of Calabar female hostel and Goldie market dumpsites which were labeled S1, S2, S3, and S4, respectively while same samples were picked from a plot of land labeled PC as a control. Arthropods were identified using light microscope and identification guide while heavy metals Cd, Pb, Cr, Ni, Co, As and Hg were analysed in soil and arthropods using Atomic absorption spectrophotometer (AAS). The results obtained showed 8363 arthropod individuals consisting of 19 species dominated by Muscidae (flies) family which constitutes about 20.39% whose presence indicates high level of pollution of the dumpsite and a possible health implication on people living around the dumpsites because these organisms are vectors for diseases such as yellow fever, malaria, Heavycholera and typhoid fever. Cadmium was the highest occurring heavy metal in dumpsites soil with a concentration of 1.457±0.493 mg/kg in S4 while As was the lowest with a concentration of 0.001 ± 0.000 mg/kg in S1 and Hg was below detection limit in all dumpsites. In arthropods, Cd had the highest occurrence with a concentration of 0.020 ± 0.001 mg/kg in S4 while Pb in S2 and Co in S1 with concentration of 0.001 ± 0.000 each were the lowest occurring metals. Heavy metals concentration in soil and arthropods from the dumpsites was higher than that of the control which shows the influences of refuse dumping and strong (> 5) positive correlation between mean metal concentrations in soil and arthropods suggests that these arthropods can be used as bio-indicators of heavy metals contamination and accumulation. It is therefore recommended that wastes be segregated and proper disposal methods should be adopted.