Ecological Implications and Source Apportionment of Heavy Metal and Hydrocarbon Contaminants in the Soil of a Poorly Crude Oil Remediated Site in Nigeria: A Case of Ikot Ada Udo Community

Abstract

The ecological risk and source apportionment of heavy metals and hydrocarbons in soil from the study site was carried out. Composite soil samples (n = 48) were collected from 3 sampling points (SP 1, SP 2, SP 3) within the site at 50, 200, and 500 meters, respectively, from the oil well and from a control site (Ibagwa, Abak) at 10,000 meters from the study site, using a hand-held auger. The samples were analyzed for heavy metals using inductively coupled plasma atomic emission spectrometry (ICP-AES, Yobin Yvon JY-24) and total petroleum hydrocarbon (TPH) using Agilent 6890N Gas Chromatography -Flame Ionization Detector (GC-FID model, Japan). Mean levels of heavy metals and TPH were higher in the study site compared to the control. The mean levels of heavy metals were 0.748 mg/kg (Pb), 0.754 mg/kg (Cd), 1.577 mg/kg (Ni), 0.274 mg/kg (Cr), 4.749 mg/kg (Fe), 0.020 mg/kg (V), 0.103 mg/kg (Co), 0.181 mg/kg (As), 5.544 mg/kg (Mn), and 5.187 mg/kg (TPH). The heavy metals in the soil had an increasing sequence of V<Co<As<Cr<Pb<Cd<Ni<Fe<Mn. The soil recorded the Cd, Cr, Fe, V, and As levels above the WHO permissible limits for soil. Ecological risk assessment revealed that Cd had the highest contamination (C i f ) (91.47%) and ecological factor (E i r ) (99.29%) in the soil, denoting that Cd contributed the most to the ecological instability and contamination of the soil. Co-relation, principal component analysis (PCA), and coefficient of variation (CV) revealed that Pb, Cd, Ni, Cr, Fe, V, As, Mn, and TPH were introduced into the soil through the crude oil spill (artificial sources), while Co originated from natural sources. A thorough clean-up of the spill site is therefore recommended to ecologically restore the soil. More of similar studies are required in other crude oil impacted soils in Niger Delta, Nigeria.

Evaluation of the Effects of Heavy Metals on Water From Illegal Crude Oil Refineries: A Case Study of Three Selected Communities in the Niger Delta Region, Nigeria

“…4), Fe (798.32%) had the highest Coefficient of variation (CV), followed by Cd (747.33%), and finally Cd (95.65%). For the apportionment of heavy metal sources, famous researchers from around the world have successfully employed statistical analysis CV (Akaninyene et al, 2021;Wang et al, 2021;Eyankware et al, 2022). With the exception of Mn, Pb, Zn, Cr, and As, which ranged from 26.83%, 27.06%, 2.642%, 26.72%, and 26.77%, respectively, the conducted study showed that the CV of Cu, Fe, Cd, and Fe pollutants were above 60%.…”

“…The region still struggles with oil pollution and contamination, which has a big impact on people despite having a rich, diverse ecology and wildlife (Amnesty International Nigeria, 2009;Ordinioha and Brisibe, 2013). The Gulf of Mexico in 2010, Canadian marine waters, and Prince Williams Sound, Alaska, all reportedly experienced oil spillage occurrences (Akaninyene et al, 2021). As about 13 million tonnes of crude oil have flowed into the Niger Delta ecosystem since crude oil was discovered there (Orisakwe, 2021).…”

“…Studies conducted revealed that the difficulties faced in managing these adverse effects posed by the activities of illegal refiners have potentially contaminated the water in the immediate environment, which has raised a significant concern in the area (Ojewumi et al, 2017;Akaninyene et al, 2021;Ikezam et al, 2021). Additional research has demonstrated that the suppression of the primary functions of the flora and fauna caused by the buildup of heavy metals in aquatic ecosystems, which makes the water unsafe to drink, is caused by the use of crude oil and other petroleum products (Barenboim et al, 2015;Agoha, 2019).…”

Heavy metal co-resistance with antibiotics amongst bacteria isolates from an open dumpsite soil

“…Sources of these metals such as mercury, cadmium, copper, and zinc vary and they include solid wastes [ 20 , 21 ] as well as agriculture and aquaculture [ 11 , 35 ]. As these metals accumulate in the environment, at certain critical levels, they trigger co-selection mechanism with antibiotics resistance [ 53 ].…”

“…The limits of detections were 0.052 (Pb), 0.018 (Cd), 0.015 (Mn), 0.025 (Ni), 1.790 (Zn), 0.079 mg/kg (Cr), 0.02 mg/kg (Fe) and 0.01 mg/kg (Co). Concentrations of heavy metals were expressed in mg/kg dry weight [ 35 ].…”