Static air samplers (SAS) are commonly used to monitor workplace conditions, but can underestimate concentrations in air in the breathing zone of a worker. Marshall and Stevens [26] reported that PAS:SAS air concentration ratios can vary from less than 1 up to 50, depending on the nature of the work. Britcher and Strong [27] concluded from their review of monitoring data for Magnox plant workers that intakes assessed from PAS data were about an order of magnitude greater than those implied by SAS data. Nevertheless, if SAS devices are sited appropriately, a comparison of PAS and SAS measurements can be used to define a fixed PAS:SAS air concentration ratio which can be used in the interpretation of SAS measurements for dose assessment purposes. It should, however, be recognised that the use of SAS is a relatively indirect method for assessing doses, and use of the results to estimate individual dose requires a careful assessment of exposure conditions and working practices. Apart from their potential use for dose estimation, SAS devices can also provide useful information on radionuclide composition, and on particle size if used with a size analyser such as a cascade impactor.

 

Overall the use of PASs and SASs can be an important part of a comprehensive workplace monitoring programme and is able to provide an early indication of risk of exposure., However, experience of the use of PASs and SASs indicates that body activity measurements and/or excreta analysis are to be preferred for the assessment of individual intakes of airborne radionuclides and doses.