Unattached radon progeny as an experimental tool for dosimetry of nanoaerosols: proposed method and research strategy.

In this paper the authors discuss a method using 1-nm particulate radon decay products as an experimental tool in the study of local lung deposition and dosimetry for nanoaerosols. The study of aerosol exposure and dosimetry measurements, and related quantitative assessment of health effects, are important to the understanding of the consequences of air pollution, and are discussed widely in the scientific literature. During the last 10 years the need to correlate aerosol exposure and biological effects has become especially important due to rapid development of a new, revolutionary industry--nanotechnology. Quantitative assessment of aerosol particle behavior in air, in lung deposition, and dosimetry in different parts of the lung, particularly for nanoaerosols, remains poor despite several decades of study. Direct nanoparticle dose measurements on humans are still needed in order to validate the hollow cast, animal studies, and lung deposition modeling. The issue of the safe use of radon progeny in such measurements is discussed. One of the properties of radon progeny is that they consist partly of 1-nm radioactive particles called unattached activity; having extremely small size and high diffusion coefficients, these particles can be potentially useful as radioactive tracers in the study of nanometer-sized aerosols.