The radium legacy: contaminated land and the committed effective dose from the ingestion of radium contaminated materials

Tyler, A.N., Dale, P., Copplestone, D., Bradley, S., Ewan, H., McGuire, C. and Scott, E.M. (2013) The radium legacy: contaminated land and the committed effective dose from the ingestion of radium contaminated materials. Environment International, 59, pp. 449-455. (doi: 10.1016/j.envint.2013.06.016)

Abstract

The manufacture and use of radium in the early to mid-20th century within industrial, medicinal and recre- 37 ational products have resulted in a large number of contaminated sites across a number of countries with no- 38 table examples in the USA and Europe. These sites, represent a significant number of unregulated sources of 39 potential radiological exposure that have collectively and hitherto not been well characterised. In 2007, the 40 Radioactive Contaminated Land (RCL) Regulations came into force in the UK, providing the statutory guid- 41 ance for regulators to classify and deal with RCL. Here we report on results derived from digestion experi- 42 ments to estimate committed effective dose, a key aspect of the RCL Regulations, from the ingestion of 43 radium contaminated sources that can be found in the environment. This case study includes particles, clin- 44 ker and artefacts that arise from past military activities on a site that was once an airfield at Dalgety Bay on 45 the Firth of Forth, UK. Since 2011 the number of radium contaminated finds has increased by one order of 46 magnitude on the foreshore areas of Dalgety Bay. The increase in finds may in large part be attributed to a 47 change in monitoring practice. A subsample of sixty sources was selected, on the basis of their activity and 48 dimensions, and subjected to digestion in simulated stomach and lower intestine solutions. The study dem- 49 onstrated that more radium-226 (226Ra) and lead-210 (210Pb; driven by Polonium solubility) are dissolved 50 from sources in artificial ‘stomach’ solutions compared with ‘lower intestine’ solutions. The combined ‘gut’ 51 solubility for 226Ra and apparent 210Pb varied from less than 1% to up to 35% ICRP 72 conversion factors 52 were used to convert the activities measured in solution to committed effective dose. A little over 10% of 53 the sources tested dissolved sufficient radioactivity to result in 100 mSv committed effective dose to an in- 54 fant. Using the solubility of 35% as a worst case, minimum source activities necessary to deliver 100 mSv to 55 the full age range of users of the foreshore were estimated. All the estimated activities have been detected 56 and recovered through routine monitoring.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Scott, Professor Marian
• Authors: Tyler, A.N., Dale, P., Copplestone, D., Bradley, S., Ewan, H., McGuire, C., and Scott, E.M.
• College/School: College of Science and Engineering > School of Mathematics and Statistics > Statistics
• Journal Name: Environment International
• Publisher: Elsevier
• ISSN: 0160-4120
• ISSN (Online): 1873-6750