Ecological vulnerability assessment of trace metals in topsoil around a newly established metal scrap factory in southwestern Nigeria: geochemical, geospatial and exposure risk analyses

Abstract

In this study, geochemical, geospatial and exposure risk analyses were combined to assess the ecological vulnerability to toxic metals of topsoil around a metal recycling factory in southwestern Nigeria. Samples of topsoil around the facility were collected and analyzed for Cd, Zn, Pb and Fe by atomic absorption spectrophotometer. Enrichment factors (EF) with reference to local background values were calculated to assess the extent of contamination of the topsoil. EF values showed that topsoil was moderately enriched with Cd and Zn, while the Pb level in the topsoil was close to the reference value. Spatial mapping of concentrations indicated potential ecological hazard (PEH) from Cd at the N, SW and SE of the factory; isolated zones of Pb within PEH at the N and SE, whereas 70 % of the area displayed Zn concentrations at the PEH threshold. Mapping of EF Cd showed a differential pattern of EF levels, with isolated hotspots of extreme and high enrichments at the N and S, respectively. Ninety-nine percent of the studied topsoil around the factor was minimally enriched in Pb, while EF Zn mapping indicated minimal to moderate enrichment. The immediate surroundings of the factory are moderately enriched in Zn, while the extreme N was minimally enriched. Exposure risk assessment gives an estimated hazard index that implies no current risk of health hazards for humans. However, it is advised that an effective pollution control should be implemented, because there is the possibility of increased hazard as production continues.

Health Risk Assessment of Children Exposed to the Soil Containing Potentially Toxic Elements: A Case Study from Coal Mining Areas

“…A human health risk model was applied in the land-use soils for the risk assessment of PTEs through three exposure routes (ingestion, inhalation, and dermal contact) in the children population. The potential health risk was assessed by calculating the hazard quotient (HQ), which is the ratio of the analyzed dose of PTEs through each exposure route and the corresponding reference exposure dose (RfD) [22]. The assessment of human health risk includes the following basic steps: (a) Hazard identification: identification of the available toxic element in the soils are the aim of the hazard identification step.…”

Sources, Transport Pathways and the Ecological Risks of Heavy Metals present in the Roadside Soil Environment in Urban Areas

“…Consequently, several recent studies have focused on the ecological risk assessment of heavy metals present in different soil environments, for example, in gold mine soil environment (Li et al, 2014), soil impacted by oil industry activities (Fatoba et al, 2016), soil at a waste disposal site (Ihedioha et al, 2016), soil around metal recycling plant (Ogunkunle et al, 2016) and around a cement factory (Ogunkunle et al, 2013). Similarly, many studies have investigated human health risks through plant uptake of heavy metals present in soil (Ogunkunle et al, 2015.…”

Scrap Metal Deposits as Potential Sources of Enhanced Risk in Soil and Vegetation

“…The dust originating from the scrap smelting process can also be a substantial environmental risk [10]. Karlaviciene et al [11] and Ogunkunle et al [12] identified Cd, Cr, Ci, Ni, Zn, and Pb as the risk elements predominantly connected with potential topsoil contamination around a metal recycling factory. According to Owoade et al [13], the atmospheric dissemination of the metal particles via particulate matter (PM) should be taken into account.…”