Development and validation of a continuous particle alpha radioactivity sampler (PARS) to measure the gross alpha activity of ambient particulate matter

Ambient particle radioactivity (PR) predominantly originates from the attachment of short-lived (SL) radon radionuclides to accumulation mode ambient particles both indoors and outdoors. These radioactive particles can be inhaled and deposited in the lungs, where they continue to decay, resulting in internal exposures. Alpha-emitting radionuclides cause more biological damage internally than either beta- or gamma-emitting radionuclides due to their high linear energy transfer over short distances. Investigating the health effects of environmental exposures to PR, specifically particle alpha activity, is a relatively novel field of study. Recent epidemiological studies have shown associations between ambient PR exposures and a variety of human health effects; however, there is very little information available about ambient particle alpha activity exposures, especially since these are dominated by SL radionuclides. We have developed a particle alpha radioactivity sampler (PARS) which provides time-resolved/continuous measurement of SL particle gross alpha activity at environmentally relevant concentrations both indoors and outdoors. PARS measurements compare well with integrated gross alpha measurements. Collocated PARS have excellent precision during hourly measurement. PARS is suitable for use in exposure assessment or indoor/outdoor air chemistry studies and can be used to investigate the complex relationship between radon and ambient particle radioactivity. Copyright © 2025 American Association for Aerosol Research