Title: The Low-Level Radiation Puzzle
Author: MATTHEW L. WALD
Date: May 2, 2012, 10:34 am
[In the Bulletin of the Atomic Scientists May-June issue Dr. Jan Beyea, an environmental scientist who has opposed nuclear reactors
for decades and worked on epidemiological studies at Three Mile Island,] challenges a concept adopted by American safety regulators about small doses of radiation. The prevailing theory is that the relationship between dose and effect is linear – that is, that if a big dose is bad for you, half that dose is half that bad [...]
Some radiation professionals disagree, arguing that there is no reason to protect against supposed effects that cannot be measured. But Dr. Beyea contends that small doses could actually be disproportionately worse.
Radiation experts have formed a consensus that if a given dose of radiation delivered over a short period poses a given hazard, that hazard will be smaller if the dose is spread out. To use an imprecise analogy, if swallowing an entire bottle of aspirin at one sitting could kill you, consuming it over a few days might merely make you sick. [...]
Dr. Beyea, however, proposes that doses spread out over time might be more dangerous than doses given all at once. He suggests two reasons: first, some effects may result from genetic damage that manifests itself only after several generations of cells have been exposed, and, second, a “bystander effect,” in which a cell absorbs radiation and seems unhurt but communicates damage to a neighboring cell, which can lead to cancer. [...]
The subject of low-dose radiation [...] has assumed renewed importance since the meltdown of the Fukushima Daiichi reactors in Japan in March 2011. The accident contaminated the surrounding area, and questions persist about whether residents should be allowed to return or whether the radiation doses they would receive are too big a threat to their health.
Read the report here
Published: May 2nd, 2012 at 3:22 pm ET