The significance of dose rate in assessing the hazards of domestic radon exposure.
Health Phys 1994 Jul; 67(1):76-79
The possibility that domestic radon exposure is underestimated by studies performed on uranium (7440611) miners because domestic exposure occurs at lower rates than uranium miners was examined. A biophysical model which suggested that cells in a certain period of their growth cycle were more sensitive to radiation than cells not in this period was used. Basic biophysical arguments implied that if a target cell is hit by one or zero alpha particles, it cannot show a dose rate effect of any kind. The resulting overall effects result from a complex interplay between cumulative exposure and exposure rate. The protraction effect increases as the exposure rate decreases, and decreases as the cumulative exposure itself decreases. Domestically, an average lifetime exposure of about 14 working level months results in less than 1% of segmental bronchioepithelial cell nuclei receiving a multiple traversal. In miner studies, even though exposure rates are higher, it is compensated for by higher exposure, which results in significant protraction related enhancement. The author cautions that this conclusion is essentially model independent, depending only on the theory that a significant dose rate effect of any kind requires the exposure of target cells to multiple alpha particle traversals.
NIOSH-Publication; NIOSH-Grant; Pulmonary-system-disorders; Dose-response; Biophysics; Ionizing-radiation; Uranium-miners; Mining-industry; Analytical-models
Radiology Columbia University Health SCi6 30 West 168Th St New York, NY 10032