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

• Published in: Environment international Vol. 59; pp. 449 - 455
• Main Authors: Tyler, A.N., Dale, P., Copplestone, D., Bradley, S., Ewen, H., McGuire, C., Scott, E.M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-09-2013; Elsevier
• Subjects: Beaches; Biological and medical sciences; Biological effects of radiation; Committed effective dose; Contaminated land; Contamination; Dalgety Bay; Digestion; Dissolution; Dose-Response Relationship, Radiation; Eating; Environment. Living conditions; Environmental Exposure - legislation & jurisprudence; Environmental pollutants toxicology; Fundamental and applied biological sciences. Psychology; Hot particles; Humans; Ingestion; Intestine, Large; Intestines; Medical sciences; Public health. Hygiene; Public health. Hygiene-occupational medicine; Radiocontamination; Radium; Radium - analysis; Radium - standards; Regulations; Soil Pollutants, Radioactive - analysis; Soil Pollutants, Radioactive - standards; Solubility; Stomach; Tissues, organs and organisms biophysics; Toxicology; United Kingdom; United Kingdom; Europe; ANE, British Isles, Scotland, Firth of Forth; USA; British Isles; ANE, Europe; Contaminated land; Hot particles; Beaches; Committed effective dose; Dalgety Bay; Radium; Military installation; Oral administration; Radioactive contamination; Soil pollution; Ingestion; Bay; Effective dose; Alpha particle
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/j.envint.2013.06.016

The manufacture and use of radium in the early to mid-20th century within industrial, medicinal and recreational products have resulted in a large number of contaminated sites across a number of countries with notable examples in the USA and Europe. These sites, represent a significant number of unregulated sources of potential radiological exposure that have collectively and hitherto not been well characterised. In 2007, the Radioactive Contaminated Land (RCL) Regulations came into force in the UK, providing the statutory guidance for regulators to classify and deal with RCL. Here we report on results derived from digestion experiments to estimate committed effective dose, a key aspect of the RCL Regulations, from the ingestion of radium contaminated sources that can be found in the environment. This case study includes particles, clinker and artefacts that arise from past military activities on a site that was once an airfield at Dalgety Bay on the Firth of Forth, UK. Since 2011 the number of radium contaminated finds has increased by one order of magnitude on the foreshore areas of Dalgety Bay. The increase in finds may in large part be attributed to a change in monitoring practice. A subsample of sixty sources was selected, on the basis of their activity and dimensions, and subjected to digestion in simulated stomach and lower intestine solutions. The study demonstrated that more radium-226 (226Ra) and lead-210 (210Pb; driven by Polonium solubility) are dissolved from sources in artificial ‘stomach’ solutions compared with ‘lower intestine’ solutions. The combined ‘gut’ solubility for 226Ra and apparent 210Pb varied from less than 1% to up to 35% ICRP 72 conversion factors were used to convert the activities measured in solution to committed effective dose. A little over 10% of the sources tested dissolved sufficient radioactivity to result in 100mSv committed effective dose to an infant. Using the solubility of 35% as a worst case, minimum source activities necessary to deliver 100mSv to the full age range of users of the foreshore were estimated. All the estimated activities have been detected and recovered through routine monitoring.
•The contemporary importance of radium contamination from early 20th century uses•Assessment of committed effective dose from the ingestion of radium particles•Case study from Dalgety Bay; a high profile ex-military airfield in the UK•Demonstration of the availability of radium and the age groups at particular risk•Interpretation within the UK's Radioactively Contaminated Land Regulations