scholarly journals Soil Invertebrates As Bio-Monitors of Toxic Metals Pollution in Impacted Soils

2015 ◽  
Vol 10 (2) ◽  
pp. 367-385 ◽  
Author(s):  
Imaobong Udousoro ◽  
I. U Umoren ◽  
J. M Izuagie ◽  
C. U Ikpo ◽  
S. F Ngeri ◽  
...  

The bio-indicator potentials of two invertebrate species, Eudrilus eugeniae (earthworm) and Pachybolus ligulatus (millipede) in toxic metals impacted soils in Akwa Ibom State, in the Niger Delta region of Nigeria were assessed. The study involved collection of Eudrilus eugeniae and Pachybolus ligulatus, and their site soil samples from different impacted and non-impacted soils in ten locations spread over four Local Government Areas. Toxic metals (Pb, Fe, Zn, Ni and Cd) in soils and in the bio-indicator organisms were analysed using Atomic Absorption Spectrometry, after acid digestion. Geo-accumulation Index (Igeo) was used to measure the extent of soil pollution; Bio-Accumulation Factor (BAF) to compute the metal uptake from soil by bio-indicators; and multivariate statistics to identify interrelationships among metals and the pollution sources. Metals in all soils were higher than the background levels, and were classified as unpolluted to very strongly polluted. Pb, Fe, Zn and Cd were higher in Eudrilus eugeniae, and Ni in Pachybolus ligulatus at 0.05 level. The organisms absorbed all metals (BAF<1), but Eudrilus eugeniae accumulated Cd and Fe and Pachybolus ligulatus, Ni and Fe (BAF>1). Metals were clustered into three (Eudrilus eugeniae) and two (Pachybolus ligulatus) dissimilar groups. Two principal components extracted, each for Eudrilus eugeniae and Pachybolus ligulatus accounted for 64% and 72% of total variations, respectively. The invertebrates exhibited varying levels of affinity in metals uptake. Eudrilus eugeniae appeared to accumulate Pb, Fe and Cd more, and could serve as a better bio-indicator for monitoring these metals. Pachybolus ligulatus accumulated 3-folds more Ni, and could provide a monitoring tool especially in agriculture, in the Niger Delta Region of Nigeria, plagued by crude oil pollution of its land and water bodies.

2021 ◽  
Vol 8 (1) ◽  
pp. 81-93
Author(s):  
Etiese Etuk ◽  
Kingsley C. Ogboi ◽  
C. A. Nwadinigwe ◽  
Wali Elekwachi

The Niger Delta region has witnessed environmental pollution arising from oil activities over the years of oil exploration and production. Soil fertility in both the Lowland Forest Ecological Zone and Island Forest Ecological Zone were investigated to establish the consequences of oil pollution on the soil and remedial actions to restore back quality and fertility of the soil. A suitable cost effective and environmentally friendly technology to handle the pollutions in the Niger Delta region can be found in Remediation by Enhanced Natural Attenuation Process (ENAP) which facilitates the activities of microorganisms to biodegrade the hydrocarbon impacted soil. The study compared the bio-physicochemical parameters of the oil spill polluted soil with particular reference to areas of oil production of the two Ecological Systems with those of the unaffected soil as well as their response to bioremediation interventions using ENAP. The results demonstrated significant decrease in the values of the key indicator parameter, the Total Petroleum Hydrocarbons (TPH). But for the unenhanced process, the result showed low level of reduction of TPH values for the polluted soils. A degradation trend was demonstrated with time leading to significant TPH reductions and improved key soil fertility indices. The result showed that the level of the nutrient status of soil in the region can be improved through the natural attenuation process.


2021 ◽  
Author(s):  
Deinkuro Nimisngha Sanchez ◽  
Charles W. Knapp ◽  
Raimi Morufu Olalekan ◽  
Nimlang Henry Nanalok

Abstract Background: Over the years, the issue of environmental degradation of ecological resources from crude oil pollution and its human health impacts is receiving more global attention. The utilization of environmental models capable of predicting the fate, transport and toxicity of chemicals in spilled crude oil can provide essential knowledge required to deal with the complexity associated with the fate of volatile petroleum chemicals in the environment. Objective: This paper explores environmental fate of toxic volatile organics from oil spill in the Niger Delta Region of Nigeria.Methods: A critical analysis of available literatures/data from PubMed, Scopus, ResearchGate, Google Scholar, Jstor, including expert working group reports and environmental modeling using a screening tool (USEPA EPI Suite™) was carried out to determine the environmental partitioning of Benzene, Toluene and Naphthalene (BTN) respectively. The organic-carbon partitioning coefficient (Koc) was computed as a function of soil-water distribution coefficient (Kd) and percentage organic matter (%OM). This was utilized to determine the distribution of BTN in the environment and the possible risk posed on delicate ecological resources from crude oil pollution due to exploration and production activities within the Niger Delta Region (NDR), Nigeria. Results: Results from literature implicated sabotage and operational failures from pipelines as primary causes of crude oil spillages. Generation of a fugacity model using EPI Suite™ revealed that the behavior of BTN is greatly influenced by Koc values. The default Molecular Connectivity Index (MCI) showed that benzene and toluene will partition more into the water compartment while naphthalene will partition into the soil compartment. However, user-entered values showed all three chemicals partitioning more into the soil compartment. Aquatic toxicology estimation using Ecological Structural Activity Relationship (ECOSAR) revealed all chemicals not to be toxic even at over-estimated Koc values. Conclusion: This research established the usefulness of screening level environmental modelling tools in assessing environmental risk and hence helpful in developing site-specific models for monitoring chemicals in the environment which can assist governments, policy makers and industries in the design of appropriate regional disaster management plans.


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