TITLE:
Ecotoxicological Dynamics of the Coastal Soil Ecosystem of Oil Producing Regions of Ondo State, Nigeria
AUTHORS:
Adenike A. Akinsemolu, Felix A. Akinyosoye, Daniel J. Arotupin
KEYWORDS:
Anthropogenic Growth, Crude Oil Extraction, Ecotoxicity, Toxic Heavy Metals, Ilaje
JOURNAL NAME:
Open Journal of Ecology,
Vol.8 No.4,
April
27,
2018
ABSTRACT: The industrial revolution
marked the beginning of unprecedented anthropogenic growth and technological
advancement that also inadvertently led to acute environmental degradation.
This technological advancement was driven by the use fossil fuels such as crude
oil. Crude oil extraction through drilling has resulted in widespread
environmental pollution and deterioration of natural habitats. The Ondo State
region in Nigeria presents one such expanse where large scale crude extraction
operations have caused hazardous environmental pollution and toxic substance
contamination. This study is a comprehensive and holistic study of the
terrestrial soil ecosystem aimed towards elucidating the potential ecotoxicity
that may have adversely affected the area. The results indicated that the
terrestrial soil ecosystem was largely acidic (~pH6) and the organic matter
content ranged from 6% to 12% indicating the soil was hydric. The results also
indicated that the terrestrial soil environment was contaminated with toxic
heavy metals including cadmium (Cd), chromium (Cr), lead (Pb) and arsenic (As).
The toxic heavy metal concentration of the soil ecosystem was higher during the
dry season. The Cr concentration in the soil samples was >3 ppm in most of
the sampling sites, which exceeded WHO maximum permissible limit. Mean
concentrations of the heavy metals in the soil samples in both seasons were of
the order: Cr > Pb > Cd > As. The soil ecosystem was also characterized by a diverse and large
population of microorganisms including bacteria like Enterobacter, Escherichia
coli, and several species of fungi.