Asbestos contamination on brownfield development sites in the UK

Abstract

The development of brownfield sites in the UK requires site investigation for contamination as part of the regulatory planning process. This site investigation includes the collection of soil samples that are analysed for asbestos contamination. This research project analyses this untapped resource of brownfield asbestos data, using site investigation data submitted to a local Borough Council, in Surrey, UK. Over 100 site investigation reports were collected. This paper presents the trends in asbestos testing from 2001 to 2019 and data on the location, concentration, form and type of asbestos found in this Borough. The rate of asbestos detection has increased significantly, reflecting improvements in asbestos measuring techniques, to a rate of 22% for all samples tested between 2016 and 2019. The concentrations of asbestos found were very low, with 74% of samples having concentrations below the limit of detection of the laboratory and were predominantly of fibrous form. A significant proportion of samples contained more carcinogenic amphibole type. Most of the asbestos was found in the top 1 m of Made Ground soil. Site history was found to be important with gas works having the highest asbestos detection rate, though a detection rate of 10% was found in soil samples on former residential sites. This information is important to inform and update risk assessment for site workers and site remediation in relation to asbestos. Hence based upon these results, a qualitative risk chart for asbestos is presented to provide guidance and in-sight into asbestos on brownfield sites for local authorities and developers.