Radionuclides in soils in urban regions.

This PhD concerns the collection, analysis and health impact assessment of soil geochemical data in order to:

• Assess the geochemical background concentration of a number of elements, including potentially harmful radioactive elements such as uranium (U) and thorium (Th) and in soils, particularly in urban and developed areas

• Inform and support local councils, developers and the general public of any environmental or health risks. Hazard maps will be produced as part of this process utilising appropriate GIS based techniques

This project will compare and contrast soils from a number of geographical regions. The primary focus is in the London area, being supported by the British Geological Surveys London Earth project (2005-2010, published 2011; where data was collected for over 50 elements), as well as collecting and analysing new material. The London Earth project was a systematic high-density geochemical topsoil survey of the Greater London Area aimed at giving an insight into the environmental impacts of urbanisation and industrialisation as well as the characterisation of the geochemical baseline of the UK’s most populous city. This was part of a nationwide project to determine the distribution of chemical elements in the surface environment, namely the Geochemical Baseline Survey of the Environment (G-BASE).
In the process of collecting the above baseline geochemistry data it became clear that there were anomalies and patterns of associated distribution that required further analysis and investigation. One element in particular that was perhaps unexpected was raised occurrences of thorium. As a result some preliminary investigations were undertaken by Kingston University who identified one hot spot as an ex clock and munitions factory.

Other regions to be explored within the project include India where Monazite (thorium-rich) sands have been the subject of investigation from a health assessment perspective, and also from a potential energy resource perspective. There have been investigations of uranium in soils and water supplies which have highlighted potential health concerns in parts of the Punjab. Bajwa et al. (2017) undertook a pilot study to investigate uranium concentration levels of ground water being used for drinking purposes to determine health effects to the local population. Analysis revealed that 60% of 800 samples had uranium concentration higher than 30 μg/l, the WHO (2011) recommended safe limit. This may be because of urbanization and the establishment of industries (cement, chemical and fertilizer factories, coal fired thermal power plants etc.) and anthropogenic activities such as the usage of fertilizers/pesticides.

The University has a number of soil samples collected from locations such as the Chernobyl nuclear site which will be used for comparative purposes.

Analytical techniques applied to date include X-ray fluorescence spectrometry (XRFS) at the laboratories of the British Geological Survey (BGS) in Keyworth, Nottingham. This project will employ ICP-MS, XRF, SEM analysis with microprobe, gamma spectroscopy approaches as well as alpha measurement techniques.