A group of nuclear energy executives and consultants refuted the nearly 80-year-old belief that low doses of radiation can eventually cause cancer, instead positing that it produces a beneficial biological response, in an article published in the Journal of Nuclear Medicine.
They argue the long-held Linear No-Threshold Hypothesis is flawed, citing data from a long-term lifespan study (LSS) conducted by the Radiation Effects Research Foundation. Government regulatory committees using that data determined that repeated low doses can have harmful effects, but the authors point to different conclusions drawn from the LSS dataset, most notably in a 2005 French Academy of Sciences report.
According to the authors, those rival reports showed the LNTH-predicted harm wasn’t present below doses of 200 microsievert (mSv) while imaging scans are usually between five and 15 mSv. In fact, those reports demonstrate a protective biological response to radiation, reducing a patient’s cancer risk.
“It has been repeatedly shown that the dose-response relationship may reasonably be considered to be linear but only down to a threshold, below which there is no demonstrable harm and even often benefit. Yet, the Linear No-Threshold Hypothesis still rules radiation regulatory policy,” said author Jeffrey Siegel, PhD, president and CEO of Nuclear Physics Enterprises.
According to the authors, imaging philosophies such as “As Low As Reasonably Achievable” (ALARA) are misguided and flawed, reducing both the clinical benefits and the body’s adaptive response. Presuming harm at all levels of exposure creates fear of radiation among the public, possibly causing avoidance of screening or imaging procedures.
“The task before us is to undo the public’s groundless fears of low-dose radiation exposure. The medical profession must be properly re-educated, beginning with diagnostic radiologists and nuclear medicine physicians, and only then can the public be given valid information that they can trust,” said Siegel. “Furthermore, defeating the LNTH and its offspring ALARA may lead to new ways of diagnosing and treating illness, and, even more importantly, preventing it.”
However, many large governmental organizations still support the LNTH, including the National Research Council, the National Council on Radiation Protection and Measurements, and the Environmental Protection Agency.