Relevance of radon progeny measurements for the assessment of inhalation doses in groundwater utilities
Tyrväinen, Jukka T; Naarala, Jonne; Turtiainen, Tuukka (2024-04-23)
Tätä artikkelia/julkaisua ei ole tallennettu Julkariin. Julkaisun tiedoissa voi kuitenkin olla linkki toisaalle tallennettuun artikkeliin/julkaisuun.
Tyrväinen, Jukka T
Naarala, Jonne
Turtiainen, Tuukka
Published on behalf of the Society for Radiological Protection by IOP Publishing Ltd
23.04.2024
This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.
Journal of Radiological Protection : 2
Tiivistelmä
The high radon concentrations measured in the indoor air of groundwater facilities and the
prevalence of the problem have been known for several years. Unlike in other workplaces, in
groundwater plants, radon is released into the air from the water treatment processes. During the
measurements of this study, the average radon concentrations varied from 500 to 8800 Bq m–³. In
addition, the indoor air of the treatment plants is filtered and there are no significant internal
aerosol sources. However, only a few published studies on groundwater plants have investigated the
properties of the radon progeny aerosol, such as the equilibrium factor (F) or the size
distribution of the aerosol, which are important for assessing the dose received by workers.
Moreover, the International Commission on Radiological Protection has not provided generic aerosol
parameter values for dose assessment in groundwater treatment facilities. In this study, radon and
radon progeny measurements were carried out at three groundwater plants. The results indicate
surprisingly high unattached fractions (fp = 0.27–0.58), suggesting a low aerosol concentration in
indoor air. The corresponding F values were 0.09–0.42, well below those measured in previous
studies. Based on a comparison of the effective dose rate calculations, either the determination of
the fp or, with certain limitations, the measurement of radon is recommended. Dose rate
calculation based on the potential alpha energy concentration alone proved unreliable.
prevalence of the problem have been known for several years. Unlike in other workplaces, in
groundwater plants, radon is released into the air from the water treatment processes. During the
measurements of this study, the average radon concentrations varied from 500 to 8800 Bq m–³. In
addition, the indoor air of the treatment plants is filtered and there are no significant internal
aerosol sources. However, only a few published studies on groundwater plants have investigated the
properties of the radon progeny aerosol, such as the equilibrium factor (F) or the size
distribution of the aerosol, which are important for assessing the dose received by workers.
Moreover, the International Commission on Radiological Protection has not provided generic aerosol
parameter values for dose assessment in groundwater treatment facilities. In this study, radon and
radon progeny measurements were carried out at three groundwater plants. The results indicate
surprisingly high unattached fractions (fp = 0.27–0.58), suggesting a low aerosol concentration in
indoor air. The corresponding F values were 0.09–0.42, well below those measured in previous
studies. Based on a comparison of the effective dose rate calculations, either the determination of
the fp or, with certain limitations, the measurement of radon is recommended. Dose rate
calculation based on the potential alpha energy concentration alone proved unreliable.