Heavy metals are substances of great health and environmental concern owing to their high discharge rates into the environments in recent years, toxicity as well as persistence in nature. Several anthropogenic activities have been established to induce heavy metals into man's environment. Studies of this nature were lacking within the study area. Thus, this work centered on establishing the distributional patterns of heavy metal contamination indexes in soils within and around auto-mechanic workshop clusters in Yenagoa Metropolis, Nigeria. Soil samples were taken and analyzed from three soil layers (0 to 15 cm, 15 to 30 cm and 30-to 45 cm), over three distances (0 meter, 50 meters and 100 meters) from the auto-mechanic workshop clusters. Pb (5.85), Cd (5.63), Ni (4.62), Hg (4.52) and Cu (3.99) all showed evidence of considerable contamination; Cr (2.4) and Mn (2.22) showed moderate contaminations while Zn (0.73), Co (1.630 and Fe (0.82) implied evidence of low contamination. Overall degree of contamination (32.42) implied very high degree of contamination while Pollution Load Index (681.22) implied progressive deterioration of soils of auto-mechanic workshop clusters in the study area. It was noticed that levels Pb, Cu, Cd, Co, Cr, Ni, Mg and Hg encountered in this study showed evidence of anthropogenic input into soils of auto-mechanic workshop clusters, as against values of Zn and Fe which showed evidence of geogenic input. The progressive contamination scenario observed in soils of the auto-mechanic workshop clusters in this work were mainly attributable to anthropogenic activities arising from unprofessional ways artisans adopted in disposal of heavy metal-bearing wastes onto soils of the study area. This calls for serious concern as progressive deterioration of soil quality stands to induce negative health and environmental effects in no distant time.

ABSTRACT:The objective of this paper is to provide the non-existent data on land use/land cover changes in the Wilberforce Island for the purposes of determining the causes of deforestation and changes in the vegetation cover for a 13 -year period. Accordingly, 125 questionnaires were administered in five communities to determine the causes of deforestation. Satellite imageries for 2002 and 2015 were also acquired from Landsat 7 and 8 respectively and analysed with the Quantum Geography Information System (QGIS) software to obtain the various land use/land cover changes. The semi -Automatic Classification Plugin Version 4.9.1 of the QGIS was used for the land use/land cover classification with a supervised classification method. Each satellite imagery was classified into 8 categories using their reflectance values and the error matrix was used to show the level of accuracy of the classified imageries. Results from the study indicated that the major drivers of deforestation were logging, farming, building of houses and fuel wood fetching. Results from satellite imageries also showed that forest and sparse vegetation/grassland decreased from 73.34% and 10.32% to 51.34% and 8.08% between 2002 and 2015 respectively, while farmland and residential area increased from 10.71% and 0.44% to 30.575 and 1.72% for the same period respectively. It was concluded that land use/cover changes was due to deforestation to provide raw materials for wood industries, and space for agriculture and building of house for the increasing population in the area. The implications of deforestation for biodiversity and climate change have been highlighted. © JASEM https://dx

Heavy metals could be induced into new environments either naturally or anthropogenically. Anthropogenic input of heavy metals into soils has been on the increase in recent years in various towns and cities as it is a major means through which heavy metals that were not indigenous to a given geographical area could be introduced into new environments. The need to ascertain the exact anthropogenic activities responsible for discharge of heavy metals into man's environment can never be over-emphasized. Therefore, this work focused on ascertaining the current pollution status and contributory source of heavy metals around soils of auto-mechanic workshop clusters in Yenagoa Metropolis, Bayelsa State, Nigeria. Three upper soil layers (0 to 15 cm, 15 to 30 cm and 30 to 45 cm) were sampled over three distant extremes (0 meter, 50 meters and 100 meters) and analyzed. Values of i-geo showed that Zn (2.23) showed moderate to highly polluted geogenically while Pb (0.76), Cu (0.79), Cd (0.77), Co (0.63), Cr (0.65), Ni (0.83), Hg (0.48), Mn (0.94) and Fe (-0.13) showed unpolluted to moderately polluted geogenically around soils of auto-mechanic workshop clusters in the Yenagoa Metropolis. Enrichment factor has shown that Zn (1.47) was not delivered through anthropogenic but geogenic sources while Pb (11.54), Cu (10.18), Cd (13.54), Co (4.02), Cr (15.35), Ni (13.48), Hg (8.89) and Mn (4.16) were respectively delivered anthropogenically. Fe (1.00) was the normalizer. The progressive contamination scenario observed in soils of the auto-mechanic workshop clusters in this work were mainly attributable to anthropogenic activities arising from unprofessional ways artisans adopted in disposal of heavy metal-bearing wastes onto soils of the study area. This calls for serious concern as progressive deterioration of soil quality induces negative health and environmental effects which has tendencies for affecting living organisms, on the long run.

In this study, results of analyses were carried out on the physicochemical parameters of soils around auto-mechanic workshop clusters and a control site following standard procedures and methodologies within Yenagoa Metropolis for parameters like pH, conductivity, NO3, PO4, SOM, Ca, Mg, Na, K, CEC and THC.  Values for the parameters were observed, in most instances to have followed the Distance-Decay Model. In such cases, the parameters showed higher levels at the top soils (0 – 15cm) than in lower soil profiles (15 – 30cm and 30 – 45cm) and generally decreased with increasing distances (50m and 100m) from the reference points (0m) at the auto-mechanic workshop clusters, depending on influencing factors. At the auto-mechanic workshop clusters, pH varied from 6.0 to 6.8 indicating acidification of soils, conductivity varied from 594 to 10,258.20úS/cm, nitrates from 3.3 to 4.6mg/kg, phosphates from 0.4 to 0.6mg/kg, SOM from 4.4 to 6.0% and calcium from 11.4 to 26.7meq/100g. Others were magnesium from 4.8 to 9.2meq/100g, sodium from 6.7 to 17.5meq/100g, potassium from 3.5 to 5.1meq/100g, CEC from 26.5 to 44.9meq/100g and THC from 4.5 to 5.4mg/kg respectively. Thus, it could be safely stated that operational presence of auto-mechanic workshop clusters did impact the physicochemical parameters of soils within closer vicinities as topsoils (0 – 15cm) and reference points (0m) more significantly than soils farther away from their vicinities. This raises health, environmental and food productivity concerns in soils of the study area.