Low Dose-Rate Radiation Poses Little Risk to DNA?

The Science

A new study by scientists at the Massachusetts Institute of Technology suggests that the guidelines governments use to determine when to evacuate people following a nuclear accident may be too conservative. The study, led by Bevin Engelward and Jacquelyn Yanch, found that mice exposed to radiation doses about 400 times greater than background levels for five weeks had no detectable DNA. Until now, very few studies have measured the effects of low doses of radiation delivered over an extended period of time. This study is the first to measure the genetic damage seen at a level as low as 400 times background (0.0002 centigray per minute, or 105 cGy in a year). Current U.S. regulations require that residents of any area that reaches radiation levels eight times higher than background should be evacuated. The researchers say that financial and emotional cost of such relocation may not be worthwhile.

BER Program Manager

Resham Kulkarni

U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]


Olipitz, W., D. Wiktor-Brown, J. Shuga, B. Pang, J. McFaline, P. Lonkar, A. Thomas, J. T. Mutamba, J. S. Greenberger, L. D. Samson, P. C. Dedon, J. C. Yanch, and B. P. Engelward. 2012. “Integrated Molecular Analysis Indicates Undetectable DNA Damage in Mice after Continuous Irradiation at ~400-Fold Natural Background Radiation,” Environmental Health Perspectives 120(8), 1130-36. DOI:10.1289/ehp.1104294.