“Do you glow in the dark?”
This is a question many Tri-Citians have been asked when we visit the west side of the state. While it’s usually meant as joke, it reveals a lack of knowledge of radiation and its effects.
How much do we, as Tri-Citians who bear the brunt of these jokes, know about radiation and its effects?
For instance, many people believe that a unit of man-made radiation is different from the same unit of natural radiation. It is not.
Or that radiation levels in the Tri-Cities are appreciably different than any other part of the state. Again, they are not.
One question, which is not so easy to answer, is whether or not any level of radiation exposure is safe.
Current radiation protection standards originated over 70 years ago and are based largely upon the deaths and radiation effects to the atomic bomb victims at Hiroshima and Nagasaki.
Extensive, international studies of the victims have been conducted to establish a relationship between dose and effect. It has been well established that there is a direct and linear relationship between the high radiation dose received and the health effects, which range from death to latent cancer.
At Hiroshima and Nagasaki effects resulted from very high doses of radiation delivered in a very short period of time. It was subsequently assumed, though not observed, that even very low doses of radiation over an extended period of time also had harmful effects.
This is known as the “Linear No Threshold” or LNT principle. It was considered to be a conservative approach and prudent for the safety of radiation workers and the public.
Based upon this assumption, any level of radiation was considered to carry some risk and it became a regulatory requirement to keep radiation exposure “As Low As Reasonably Achievable” or the ALARA principle.
Until recently it was felt that the primary negative effect of the LNT model and ALARA principle were economic, for example increasing the cost of nuclear power production, cleanup and waste management.
Another effect was the reluctance, fear and avoidance of beneficial medical diagnostics and treatment.
Even more significantly, recent studies have identified deaths from evacuations after Fukushima to avoid exposure to low levels of radiation.
Approximately 19,000 people died as a result of the earthquake and tsunami in Japan on March 11, 2011. While the reactors at Fukushima shutdown safely after the earthquake, three reactors at the site were destroyed when their fuel melted and large quantities of radioactivity were released due to the improper location of backup generators.
As a result of this release of radioactivity, large-scale evacuations were conducted. While some evacuations may have been prudent, many were not.
Indeed, while there have been no fatalities or casualties due to radiation, there have been estimates of 760 to 1600 “disaster related deaths” from trauma caused by the evacuations. These evacuation-related deaths show that the conservative assumption of the LNT can have a measurable downside that needs to be reexamined.
A joint American Nuclear Society-Health Physics Society Conference on the “Applicability of Radiation-Response Models to Low Dose Protection” will be Sept. 30 to Oct. 3 in Pasco. More information can be found at LowDoseRad.org.
The conference coincides with the 75th Anniversary of the Hanford site. Experts from around the world will be here to explore the current scientific knowledge and understanding of low dose radiation effects, consider their applicability to current radiation protection standards, and recommend a path forward.
Advances in science now allow us to observe the repair mechanisms of cells to low dose radiation exposure.
Hopefully, a thorough review of this new scientific evidence will result in a sound basis for understanding radiation effects at low doses.
Based upon this scientific understanding, regulators can then consider potential changes to radiation protection standards. And if you choose to attend, you may even have a good response to the question, “Do you glow in the dark?”
Mike Lawrence was DOE Manager of Hanford from 1984 to 1990; Associate Laboratory Director for Energy at PNNL from 2002 to 2006; and Managing Director of the UK National Nuclear Laboratory 2009-2010.