Thesis
Potentially toxic elements in soils impacted by crude oil production and historical lead mining
- Creator
- Rights statement
- Awarding institution
- University of Strathclyde
- Date of award
- 2024
- Thesis identifier
- T17008
- Person Identifier (Local)
- 201989107
- Qualification Level
- Qualification Name
- Department, School or Faculty
- Abstract
- Exploration and exploitation of natural resources can contaminate soil and other environmental media with potentially toxic elements (PTE). These remain bound in the soil, bioaccumulate and pose risks to the environment and human health. This study was in two parts: optimization and application of a method to determine the pseudototal concentrations of PTE in crude oil contaminated soils collected from Rivers State, Nigeria; then determination of the pseudototal and bioaccessible concentrations of PTE in soils from the former lead mining village of Wanlockhead, Scotland. In both parts, the elements arsenic, cadmium, chromium, copper, nickel, lead, vanadium and zinc were determined by ICP-MS. Study of the influence of digestion method on the pseudototal PTE concentrations measured in crude oil contaminated soils indicated that microwave-assisted digestion using reverse aqua regia following 4 hours’ pre-digestion gave most efficient extraction. This method was used to determine PTE concentrations, while the SBET method was used to determine the oral bioaccessibility of PTE in selected soils. For most samples, both pseudototal and bioaccessible concentrations were below limits set by the Nigerian Department of Petroleum Resources and the FAO/Tanzanian Environmental Management Regulations for habitat and agricultural soils. Hence there was no evidence of risk from PTE to the local population. In contrast, many of the samples collected from public-access areas at Wanlockhead contained pseudototal and bioaccessible PTE concentrations higher – sometimes much higher – than soil guideline values for residential areas (as given in the UK Contaminated Land Exposure Assessment of 2009). Oral and inhalation bioaccessibility of PTE were found to be similar, with dermal contact representing the least significant exposure route. Some of the PTE presented potential non-cancer and cancer risks to adults and/or children. There were also risks from cumulative PTE exposure. Further study of human and environmental health in the area is therefore urgently required.
- Advisor / supervisor
- Davidson, Christine
- Resource Type
- DOI
- Funder
- Embargo Note