Personal Radon Dosimetry from Eyeglass Lenses

Abstract

Eyeglass lenses are commonly composed of allyl-diglycol carbonate (CR-39), an alpha-particle detecting plastic, thus making such lenses personal radon dosemeters. Samples of such lenses have been obtained, etched to reveal that radon and radon progeny alpha tracks can be seen in abundance, and sensitivities have been calibrated in radon chambers as a primary calibration, and with a uranium-based source of alpha particles as a convenient secondary standard. With one exception natural, environmental (fossil) track densities ranged from less than 3,000 to nearly 70,000 per cm2 for eyeglasses that had been worn for various times from one to nearly five years. Average radon concentrations to which those wearers were exposed are inferred to be in the range 14 to 130 Bq x m(-3) (0.4 to 3.5 pCi x l(-1)). A protocol for consistent, meaningful readout is derived and used. In the exceptional case the fossil track density was 1,780,000 cm(-2) and the inferred (24 h) average radon concentration was 6500 Bq x m(-3) (175 pCi x l(-1)) for a worker at an inactive uranium mine that is used for therapy.

The Cellular and Molecular Carcinogenic Effects of Radon Exposure: A Review

“…However, there is an inherent difficult in accurately predicting or determining personal exposure dosimetry based upon values derived using alpha track detectors as often individuals can spend varying amounts of time in areas away from those that have been measured. In response, a number of studies have tried to derive a more accurate quantification of exposure through the use of plastics and other materials that a sensitive to tracks produced by alpha particles with examples including eye-glass lenses [49], passive personal dosimeters [50] and wrist watch detectors [51]. Nevertheless, accurate exposure estimates to the general population can often remain difficult to accurately obtain and the requirement for cheap, portable and reliable personal dosimeters has been acknowledged [51] and until such devices are routinely employed across multiple in vivo studies the effective comparison of exposures between laboratory based biological studies and those at physiological exposures will remain difficult to compare effectively.…”

Radon retrospective measurements

“…A prospect along this line has been suggested by Fleicher [2], the etching of alpha tracks in glasses with plastic lenses. A pair of spectacles has the potential of revealing personal exposure, but unfortunately, the wearing time of spectacles is typically only a few years.…”