The linear no-threshold theory: Readers weigh in
DOI: 10.1063/PT.3.3215
A letter in the January 2016 issue of Physics Today questioned the validity of the linear no-threshold (LNT) model of radiation damage. We would like to share the results of a study that shows a threshold effect in fruit flies. 1
In our experiment, we gave fruit flies one dose of radiation shortly after they hatched. The incident radiation exposures ranged from 0.1 J/kg to 1000 J/kg (10–100 000 roentgen). We tracked life spans and gene expression at 2 days, 10 days, and 20 days after irradiation.
We found that there was no measurable effect on lifetimes below a radiation threshold of 50 J/kg. Above that threshold, lifetimes decreased. Below it, whatever gene expression changes occur at 2 days and 10 days are corrected at 20 days. Above the threshold, the changes are not corrected.
Obviously, many questions remain, but our results clearly indicate that the LNT model is not applicable in our experiment.
References
1. M. Antosh et al., Dose–Response 12, 551 (2014). https://doi.org/10.2203/dose-response.13-047.Antosh
More about the Authors
Leon N. Cooper. (leon_cooper@brown.edu) Brown University, Providence, Rhode Island.
Michael Antosh. University of Rhode Island, Brown University, Providence, Rhode Island.
