Assessment of Heavy Metals Contamination in Soils from Open Dumpsite in Sagamu, Southwest Nigeria

Concerns over the possible health and ecological effects of accumulation of heavy metals contaminants in the soil have prompted numerous researches in recent times. This study assessed the environmental quality of soils from an open dumpsite in Sagamu to investigate the ecological risk of heavy metals. A total of 13 soil samples were collected and air o dried at 30 C. Heavy metal concentrations were determined using atomic absorption spectrophotometer. Mean heavy metal concentration in the soil were of the order Cu >Pb> Zn > Cd, which were higher than their control concentrations. It was revealed that Copper had the highest concentration (2214.25 mg/kg); based on Nemerow’s Synthetical Pollution Index (NSPI), the soils were polluted by Cu and Cd, while Pb and Zn were within the safety domain. The correlation coefficient of the heavy metals showed that Cu correlated positively with Cd and Zn (0.53 and 0.17 correlation coefficient respectively), while Pb correlated positively with Cd (correlation coefficient of 0.17). The lack of a significant correlation between Pb and other heavy metals shows that its sources were quite different from those of the others. The study further shows that Cu and Cd had high ecological risk factor than Pb and Zn. It was concluded that open dumpsite in Sagamu poses great environmental risk to water and land resources. While it was recommended that Open dumpsites should not be only sited far from residential areas but integrated waste management should be encouraged to reduce soil pollution.