Assessment of soil metals status in parts of Rivers State, Nigeria

The study evaluates levels of metals in soils of 9 locations in Port Harcourt and its environs in Rivers State in Nigeria. Composite samples were collected by random sampling from each of the 9 test locations, 3 control samples were also collected from each of the study areas. Concentration levels of (Lead) Pb, (Copper) Cu, (Cadmium) Cd, (Zinc) Zn, (Calcium) Ca, (Nickel) Ni, (Sodium) Na, (Potassium) K, (Chromium) Cr, (Magnesium) Mg, (Manganese) Mn, and (Sulphur) S in soil were measured using Atomic Absorption Spectrophotometry. The obtained mean levels of Pb, Cu, Cd, Zn, Ca, Ni, Na, K, Cr, Mn and Mg were 1.45±0.16, 0.22±0.04, 0.04±0.01, 2.61±0.51, 12.99±4.81, 0.75±0.08, 173.64±35.31, 6.06±1.58, 0.27±0.03, 4.21±0.61 and 11.87±2.10 ppm respectively. There were significant differences in levels of Pb among the test and control samples (p=.048). There was significant difference in levels of Cu among the test and control samples (p=0.001). There was significant difference in levels of Zn among the test and control samples (p=0.016). The study establishes that urbanization, industrialization and agricultural activities do affect the level of metals in the soils of the study areas. The pollution of soils with metals in the studied sites is within permissible limits, however, levels of Zn, Cd and Ni should be on close monitoring to in the industrial areas and urbanized areas. The study establishes that oil and gas activities variedly affect the levels of metal pollution in urbanized, industrialized and agricultural areas.Keywords: Anthropogenic activities, Metals, Impact, Ecosystem, Integrit

Oil-Gas and Environmental Nexus: Impact of Human Actions on selected Soil Physicochemical Parameters in Port Harcourt and its environment, Nigeria

Impact of oil and gas activities on quality of soil in Port Harcourt and its environments was assessed. The study evaluates levels of physicochemical parameters associated with oil and gas industry in soils of 9 locations in Port Harcourt and its environs in Rivers State in Nigeria using standard methods. Composite samples were collected by random sampling from each of the 9 test locations, 3 control samples were also collected from each of the study areas. Benzene, Toluene, Ethyl-benzene, and Xylene (BTEX) and Total Petroleum Hydrocarbon (TPH) was measured using Gas Chromatography (Hewlett Packard 5890 Series II Gas Chromatograph FID). Total Organic Carbon (TOC) was measured using ASMD standard methods of analysis (ASMD 2579). Refinery Eleme and Aluu recorded the highest mean levels of BTEX (3.21±0.61 and 3.24±0.18 ppm respectively). The mean levels of TPH in soil were within the EPA acceptable optimum of 50 mg/kg except at A2 (Oquwi). There was significant difference among test samples and control samples as determined by one-way ANOVA (F11, 24=3.395; p=0.006). The highest mean levels of TPH was at A2 (56.70±25.77 ppm). ANOVA revealed that there were significant differences in TOC (p=0.023), BTEX (p=<0.001) and TPH (p=<0.001) among the study areas. Industrial areas I1 [Onne], I2 [Agbada] and I3 [Trans-Amadi] recorded highest levels of TOC. Oil and gas activities in industrial areas in Port Harcourt have highest impact on levels of TOC in soils as compared to agricultural and urbanized areas. Oil and gas activities have negative impact on levels of BTEX. Industrial areas recorded highest levels followed by agricultural areas and lastly urbanized areas. The study concludes that oil and gas activities are a threat to soil health and integrity in Port Harcourt.Keywords: oil, gas, environment, soil, pollution, physicochemical parameters, nexu

Evaluation of the Effects of Cadmium in Soil on the LC50 of Soil Bacteria and Fungi for Environmental Monitoring

Contamination of soil with heavy metals by is currently of global concern. Cadmium (Cd) is one of the metals of concern. In the current study, LC50 of Cd to soil bacteria and fungi was used to assess the impact of anthropogenicactivity in development of Cd tolerance in soil microorganisms. Levels of Bio-physicochemical parameters in soil were determined. Results show that the concentration of Total Petroleum Hydrocarbon (TPH) and Cd in soil ranged between 5.09±0.33 to 9261.94±287.67, and 0.023±0.015 to 0.057±0.012 ppm respectively. There was significant difference (p = 0.001) in LC50 for fungi between the study and control samples. Pearson correlation showed that there was significant relationship (r = 0.30) between LC50 for bacteria and TPH. There was significant difference (p = 0.017) in LC50 values among the study and control samples for fungi. Anthropogenic activities influenced the concentrations of TPH soil but did not influence levels of Cd

Assessment of Ni Toxicity to Fungi and Bacteria in Oil Tainted Soils in Greater Port Harcourt Area, Nigeria

Intensified urbanization and industrialization are rapidly triggering the release of pollutants to the environment. This study determined the extent of soil contamination with Nickel (Ni) in oil mining areas and its effect on the levels of Ni tolerance by fungi and bacteria. The total CFUs/g of soil were enumerated after a culture period of 7 days at 28°C and LC50 was determined using probit and regression analysis. The mean values of Ni were 1.38±0.23 in industrial area, 1.41±0.36 ppm in agricultural area and 1.02±0.64 in urban area. The mean values of Total Petroleum Hydrocarbon (TPH) were 4,405.46 ppm in industrial area, 55.65 ppm in agricultural area and 1,304.53 ppm in urban area. Nickel’s peak concentration indicating growth of both fungi and bacteria at 150 ppm. There was significant difference (p ≤ 0.000) in the mean levels of LC50 for fungi among the study sites. There was no significant correlation between the concentration of TPH in soil and LC50 of fungi (r = -0.169) and bacteria (r = 0.042). In conclusion, TPH influenced the levels of fungi and bacteria tolerance to Ni in soils. Moreover, it was observed that LC50 can be a reliable method for monitoring chemically resistant microorganisms directly in the environment to improve the use of microorganisms for the bioremediation of oil contaminated soils and in monitoring of antibiotic resistant microorganisms in natural ecosystems