Assessment of Dumpsite Soils in Mangrove Forest at Eagle Island, Nigeria: It’s Effect on Potential Bioavailability of Heavy Metals in the Environment

Abstract

Heavy metals can be absorbed by plants resulting to contamination of other organisms in the food chain. This study was intended to determine heavy metals in soil, their mobility factor and impact on flora and fauna. To determine bioavailability of metal ions in soil chemical speciation and mobility factor indices were calculated. The level of Fe, Pb, Zn and Cd in readily available forms were assessed in dumpsite soils within mangrove forest in the Eagle Island and compared with control (i.e., relatively undisturbed soil). The aim of the study was to evaluate the impact and contribution of municipal waste discharge on alteration of soil quality and bioavailability of metals within the soil matrix. Samples of soil were collected in triplicate from five locations across the dump area while the control point was established at a less impacted area. Sampling was done in November 2018. Concentration of metal ion/species was analysed using GBC Avanta PM A6600 atomic absorption spectrophotometer. Soils of the sampling area were acidic with pH values ranging between 4.55 and 5.74. The most important heavy metal fractions in the dumpsite soils were; Fe (residual fraction, 53.75%), Pb (residual fraction, 42.58%), Zn (Fe-Mn oxide fraction, 46.85%) and Cd (carbonate bound fraction, 37.77%). However, the less impacted soil was predominantly affiliated to the residual fractions of Fe (68.75%), Pb (54.86%), Zn (37.45%) and Cd (51.51%). Heavy metal mobility factor indices reflected the order: (Cd>Pb>Zn>Fe) for soils of both the solid waste dumpsite and control areas. Despite the prevalence of heavy metals to the inert fractions, the significant affiliation of Cd to the readily mobile fractions of waste dump soils may suggest its release to have come from toxic constituents such as petroleum products that are associated with municipal wastes.

Assessment of Heavy Metals Contamination of Water and Cupscale Grass (Sacciolepisafricana) along the Epie Creek in Bayelsa State, Nigeria

“…The spike in iron may be from the turbid appearance of water samples emanating from soil runoffs or leachates from increasing anthropic occurrences of waste dumpsites. A greater mobility factor of 0.84% for iron in dumpsite environments as compared to 0.71% in uncontaminated control habitats has been reported in a previous study [27].…”

A Survey of Concentrations and Source Characterization of Polycyclic Aromatic Hydrocarbons in Surface Waters of the Imiringi River System

“…Hence, river systems are often prone to contamination, which mostly emanates from anthropogenic activities. Consequently, complex mixtures of persistent organic pollutants (POPs) are released in the form of total petroleum (TPHs), polycyclic aromatic hydrocarbons (PAHs) and volatile aromatic mixtures (VAMs) such as phenol, benzene, toluene, ethylbenzene, xylene [1], inorganic micro-pollutant trace/heavy metals [2][3][4][5], as well as proliferating microbial densities [6], amongst others.…”

Impact of Human Disturbance on Fiddler Crab (<i>Uca tangeri</i>) Burrow Morphology, Distribution and Chemistry at Eagle Island, Niger Delta, Nigeria

“…The detection limit for the three metals analyzed in mg/l i.e. Zinc, Cadmium and Lead is 0.001, 0.001 and 0.002 respectively [19].…”