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Biomedical subjects

A R Denman

Publications and source records attributed to A R Denman.

26 records · Page 2Linked to original sources
PubMed1999

Do the UK workplace Radon Action Levels reflect the radiation dose received by the occupants?

In the UK, Action Levels for radon have been established at 400 Bq m(-3) for the workplace and 200 Bq m(-3) for the home. We have estimated the dose received by occupants of rooms with radon levels near or above the Action Level, using hourly radon readings, and a questionnaire to record occupancy. In the workplace, results for 73 staff suggest that doses are lower than expected, partly due to part-time working and partly due to the mobility of staff. The 75% quantile for the series, corrected to a 37 hour week, is 5.2 mSv at 400 Bq m(-3). Compared to the current annual limit for radiation workers, the Action Level could be increased, but the current Action Level is compatible with the recent EEC Directive requiring a lower dose limit. However, when raised radon levels in the workplace were reduced by remediation in the series we studied, the dose reduction to staff was consistently around half of the radon level reduction. Although it would be appropriate to study more locations, this suggests an Action Level for remediated workplaces of 200 Bq m(-3). Finally, in a limited series of dose assessments in domestic properties, we found that doses could considerably exceed 5 mSv at the 200 Bq m(-3) Action Level, primarily because the sample included an example of high occupancy, in our case several Asian wives in purdah, whose occupancy was almost total.

Air Pollutants, Radioactive↗
PubMed1998

A review of the cost effectiveness of radon mitigation in domestic properties in Northamptonshire.

The costs of remedial work, and the radon level reduction achieved, have been studied in a series of domestic properties in Northamptonshire, which is a radon affected area. The cost-effectiveness of the series is similar to published theoretical estimates for proposed national remediation programmes, and five times more effective than our similar analysis for the National Health Service workplace, if it is assumed that 100% of householders discovering levels above 300 Bq m-3 implement remediation. In practice, in the UK, far fewer of those who arrange an initial radon test proceed to remediation, but this domestic programme could be cost effective if more than 5% carry out remediation. Our series confirms that a considerable number of householders with radon levels in the 200 to 300 Bq m-3 range do not seek or implement remediation work.

Air Pollution, Indoor↗
PubMed1998

The cost-effectiveness of radon mitigation in schools in Northamptonshire.

A comprehensive radon survey of 2372 rooms in 348 Northamptonshire schools is reported, together with results of the successful mitigation of the raised radon levels found in 20 schools. From analysis of the occupancy of affected rooms and the costs of remediation a total cost of 19,400 Pounds per man-sievert saved annually was derived. This is around four times more cost-effective than the radon remediation in Health Service premises in Northamptonshire, and slightly more cost-effective than a domestic programme where all householders with radon levels above the Action Level carry out remediation. As only a small percentage of householders undertook remediation, a schools' remediation programme is the most cost-effective programme to reduce radon in an Affected Area.

Adolescent↗
PubMed1997

Radon: a human carcinogen.

Radon is a naturally occurring, radioactive gas that is found in Group 0 of the periodic table. Normally, it is found in extremely low levels in air but can, in certain geological formations, be a significant component of soil gas. Doses from radon are the largest component of the average radiation exposure for the UK general population. Certain areas, e.g. Cornwall, of the UK have been found to have elevated levels of radon in dwellings and these have been classified as Affected Areas. Here authorities can declare that radon prevention measures are needed in new houses and that existing houses with high levels should be identified and remedied. In radon Affected Areas, individuals, in homes and the workplace, can be receiving high doses of radiation. There is overwhelming evidence that exposure to radon, at the levels found in mines, leads to lung cancer. But what happens when individuals are exposed to the lower levels found in homes and the majority of workplaces? There is clear biological evidence for the role of radon inducing lung cancer and the epidemiological evidence is now beginning to emerge. The population at large needs to act. When high levels are found in buildings, prompt action needs to be taken to reduce levels via proven technology.

Air Pollutants, Radioactive↗
PubMed1996

Short communication: estimates of radiation dose to National Health Service workers in Northamptonshire from raised radon levels.

Extensive surveys of the radon levels in hospital premises in Northamptonshire have shown that raised radon levels are present, but are localized to areas as small as a single office. Around 9% of sites are above the workplace action limit, and 1% of sites are over 1000 Bq m-3. In addition, radon levels vary throughout the day, and are usually higher at night. Staff in these areas could receive significant doses, and staff working shifts or at night could be at greater risk. Attempts to estimate staff dose using two methods are reported. It is concluded that, even though only a sample of the radon hot-spots was chosen, the radiation dose received by these staff is greater than the occupational exposure of radiographers, radiologists and other health workers.

Air Pollutants, Occupational↗