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

Ajah KC, Ademiluyi J, Nnaji CC - J Environ Health Sci Eng (2015)

Bottom Line: On the other hand, the concentrations of arsenic, cobalt and iron continued to decrease even at a depth of 2 m.The high pollution loading index represents a significant level of deterioration.It can be concluded that the dumpsite constitute a serious environmental and health hazard.

View Article: PubMed Central - PubMed

Affiliation: Department of Civil Engineering, University of Nigeria, Nsukka, Enugu State Nigeria.

ABSTRACT

Background: Improper waste disposal is responsible for the contamination of both surface and ground water resources. Heavy metals leached from improperly disposed solid waste constitute grave environmental and health hazards because of their toxic and persistent nature. There are thousands of open dumps in Nigeria one of which is the Enugu State Waste Management Authority dumpsite.

Method: Forty sampling nodes were systematically established around the Enugu State waste Management Authority 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 both rainy and dry seasons.

Result: Iron and lead were the predominant metals in the vicinity of the waste dump with average values of 132.10 mg/kg and 117.52 mg/kg respectively. The order of abundance of the ten heavy metals monitored is Pb > Fe > As > Zn > Cu > Co > Ni > Cd > Cr > Mn. Generally, there was significant correlation (0.25 to 0.74) among all the metals except between cobalt and manganese in the rainy season. In the dry season, all the metals were significantly correlated (0.29 to 0.813) except for copper and lead, copper and arsenic, zinc and arsenic, and cobalt and 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 concluded that the dumpsite constitute a serious environmental and health hazard.

No MeSH data available.


Related in: MedlinePlus

Seasonal variation of geoaccumulation index.
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Fig6: Seasonal variation of geoaccumulation index.

Mentions: The values of Igeo obtained for the individual metals (Figure 6) serve to further buttress the results of the PI values. Iron, manganese, copper and arsenic have the highest Igeo values, while cobalt, chromium, cadmium and zinc have Igeo values less than zero. From the Igeo values, it can be deduced that the soil is currently uncontaminated with respect to cobalt, cadmium, chromium and zinc; moderately to heavily contaminated with respect to iron and manganese; and moderately contaminated with respect to copper, lead, arsenic and nickel. From Figure 7, it appears that a substantial concentration of heavy metals is confined within the first 1 m of soil depth. This suggests that the mobility of heavy metals is affected by the concentration in the top soil. The concentrations of most of the heavy metals, specifically, chromium, manganese, copper, nickel, cadmium and zinc 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. This phenomenon confirms the suggestion that individual heavy metals, move at different rates in the soil [50]. It also suggests that individual heavy metals move in plumes. Hence the plumes or copper, lead, chromium, nickel, manganese, cadmium, and zinc are lagging behind the plume of arsenic, iron and cobalt. The rate of movement of this plume is dependent on the loading of the heavy metals on the top soil and other site characteristics. It can further be deduced that the mobility of arsenic, cobalt and iron is most favoured by condition prevailing in this site. It is also likely that these heavy metals will breakthrough to groundwater faster than other metals.Figure 6


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

Ajah KC, Ademiluyi J, Nnaji CC - J Environ Health Sci Eng (2015)

Seasonal variation of geoaccumulation index.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4363377&req=5

Fig6: Seasonal variation of geoaccumulation index.
Mentions: The values of Igeo obtained for the individual metals (Figure 6) serve to further buttress the results of the PI values. Iron, manganese, copper and arsenic have the highest Igeo values, while cobalt, chromium, cadmium and zinc have Igeo values less than zero. From the Igeo values, it can be deduced that the soil is currently uncontaminated with respect to cobalt, cadmium, chromium and zinc; moderately to heavily contaminated with respect to iron and manganese; and moderately contaminated with respect to copper, lead, arsenic and nickel. From Figure 7, it appears that a substantial concentration of heavy metals is confined within the first 1 m of soil depth. This suggests that the mobility of heavy metals is affected by the concentration in the top soil. The concentrations of most of the heavy metals, specifically, chromium, manganese, copper, nickel, cadmium and zinc 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. This phenomenon confirms the suggestion that individual heavy metals, move at different rates in the soil [50]. It also suggests that individual heavy metals move in plumes. Hence the plumes or copper, lead, chromium, nickel, manganese, cadmium, and zinc are lagging behind the plume of arsenic, iron and cobalt. The rate of movement of this plume is dependent on the loading of the heavy metals on the top soil and other site characteristics. It can further be deduced that the mobility of arsenic, cobalt and iron is most favoured by condition prevailing in this site. It is also likely that these heavy metals will breakthrough to groundwater faster than other metals.Figure 6

Bottom Line: On the other hand, the concentrations of arsenic, cobalt and iron continued to decrease even at a depth of 2 m.The high pollution loading index represents a significant level of deterioration.It can be concluded that the dumpsite constitute a serious environmental and health hazard.

View Article: PubMed Central - PubMed

Affiliation: Department of Civil Engineering, University of Nigeria, Nsukka, Enugu State Nigeria.

ABSTRACT

Background: Improper waste disposal is responsible for the contamination of both surface and ground water resources. Heavy metals leached from improperly disposed solid waste constitute grave environmental and health hazards because of their toxic and persistent nature. There are thousands of open dumps in Nigeria one of which is the Enugu State Waste Management Authority dumpsite.

Method: Forty sampling nodes were systematically established around the Enugu State waste Management Authority 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 both rainy and dry seasons.

Result: Iron and lead were the predominant metals in the vicinity of the waste dump with average values of 132.10 mg/kg and 117.52 mg/kg respectively. The order of abundance of the ten heavy metals monitored is Pb > Fe > As > Zn > Cu > Co > Ni > Cd > Cr > Mn. Generally, there was significant correlation (0.25 to 0.74) among all the metals except between cobalt and manganese in the rainy season. In the dry season, all the metals were significantly correlated (0.29 to 0.813) except for copper and lead, copper and arsenic, zinc and arsenic, and cobalt and 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 concluded that the dumpsite constitute a serious environmental and health hazard.

No MeSH data available.


Related in: MedlinePlus