Spatiality, seasonality and ecological risks of heavy metals in the vicinity of a degenerate municipal central dumpsite in Enugu, Nigeria

Background: improper waste disposal is responsible for the contamination of both surface and ground waterresources. heavy metals leached from improperly disposed solid waste constitute grave environmental and healthhazards because of their toxic and persistent nature. there are thousands of open dumps in nigeria one of which isthe enugu state waste management authority dumpsite.method: forty sampling nodes were systematically established around the enugu state waste managementauthority central dumpsite located at ugwuaji, enugu state, nigeria. ten heavy metals (arsenic, cadmium, cobalt,copper, chromium, iron, lead, manganese, nickel and zinc) were sampled at different depths of each node in bothrainy and dry seasons.result: iron and lead were the predominant metals in the vicinity of the waste dump with average values of132.10 mg/kg and 117.52 mg/kg respectively. the order of abundance of the ten heavy metals monitored ispb > fe > as > zn > cu > co > ni > cd > cr > mn. generally, there was significant correlation (0.25 to 0.74) among allthe metals except between cobalt and manganese in the rainy season. in the dry season, all the metals weresignificantly correlated (0.29 to 0.813) except for copper and lead, copper and arsenic, zinc and arsenic, and cobaltand manganese. the concentrations of most of the heavy metals approached a constant level at a depth of 1 m.on the other hand, the concentrations of arsenic, cobalt and iron continued to decrease even at a depth of 2 m.the pollution loading index values for the soil are 1.706 for rainy season and 2.54 for dry season.conclusion: the high pollution loading index represents a significant level of deterioration. it can be concludedthat the dumpsite constitute a serious environmental and health hazard.