Workplace radon in Northamptonshire

Northamptonshire is classified as a radon affected area, with greater than 1 per cent of domestic dwellings being above the UK Action Level of 200Bq m–3. Workplace radon is also a health risk in Northamptonshire, with a significant number of premises being predicted to be above this Action Level (400Bq m–3). After an extensive survey in National Health Service premises, using track etch detectors and real time monitoring systems, it was found that certain staff were receiving very high doses – up to around 20mSv. The annual collective dose from radon, in the rooms with elevated levels, was 285mSv, an average of 4.45mSv. After remediation of the rooms the average dose fell to 0.5mSv. The average cost of radon remediation in National Health Service premises was £3,950 per location. This compares to a value of £1,953 for locations in schools in Northamptonshire. It is possible that remediation costs for the majority of small to medium enterprises in the country will, on our conservative estimate of 6 per cent being above the Action Level, be in the region of £1,460,000. Further monitoring of workplace radon is taking place across the county in an attempt to determine more accurately the full extent of the problem. Introduction