Abstract Salt mining along with natural and human-induced salt dissolution affects the ground over Permian and Triassic strata in the UK. In England, subsidence caused by salt mining, brine extraction and natural dissolution is known to have occurred in parts of Cheshire (including Northwich, Nantwich, Middlewich), Stafford, Blackpool, Preesall, Droitwich and Teeside/Middlesbrough; it also occurs around Carrickfergus in Northern Ireland. Subsidence ranges from rapid and catastrophic failure to gentle sagging of the ground, both forms being problematical for development, drainage and the installation of assets and infrastructure such as ground source heat pumps. This paper reviews the areas affected by salt subsidence and details the mitigation measures that have been used; the implications for planning in such areas are also considered.

Abstract Radon ( 222 Rn) is a natural radioactive gas that occurs in rocks and soils and can only be detected with special equipment. Radon is a major cause of lung cancer. Therefore, early detection is essential. The British Geological Survey and Public Health England have produced a series of maps showing radon affected areas based on underlying geology and indoor radon measurements, which help to identify radon-affected buildings. Many factors influence how much radon accumulates in buildings. Remedial work can be undertaken to reduce its passage into homes and workplaces and new buildings can be built with radon preventative measures.

Abstract Radon ( 222 Rn) has been highlighted by a number of authors as a significant public health concern. For example, it is the second most significant cause of lung cancer after tobacco smoking ( c. 1000–2000 and 21 000 deaths per year in the UK and USA, respectively), yet a very high proportion of the general public appears to be unaware of the risk. This chapter deals with topical radon issues, such as: radon in the workplace; radon in homes; exposure to radon during leisure activities; radon and water; measurement and monitoring; seasonal correction; remediation; cancer risks; cost–benefit analysis and cost-effectiveness; mapping; future policies; and further research. This assessment of the state of radon research is focused on the UK as an example of a country where radon has been on the governmental agenda since the late 1970s, but also highlights radon issues throughout the world in, for example, the USA, Europe and Asia.