Abstract
The premises underlying the article by Pollycove and Feinendegen are unlikely to generate disagreement among most scientists. The authors do a good job of reviewing the scientific literature on the importnat topic of radiation-induced versus endogenous DNA damage, and they use the available data to calculate numerical estimates and comparisons of DNA damages induced by radiation versus metabolic processes. However, these numbers should in no way be confused with proof or disproof of the involvement of specific biological mechanisms. Many important questions for low-dose radiobiology remain unanswered, and there is no substitute for experimental demonstration.