The U. S. National Council on Radiation Protection (NCRP) held its annual meeting in Bethesda, MD on March 16 and 17. On the second day of the meeting, Jacques Lochard, Vice Chair of the International Commission on Radiation Protection (ICRP), gave a talk titled The Ethics of Radiation Protection. The slides from that talk are not yet available, but Mr. Lochard gave a similar talk in July 2014 titled ￼￼An Introduction to the Ethical Foundations of the Radiation Protection System.
Lochard started by quoting the purpose of the radiation protection system from ICRP publication 103.
“To contribute to an appropriate level of protection of people and the environment against the detrimental effects of ionizing radiation exposure without unduly limiting the desirable human actions that may be associated with such exposure.”
He focused on the human dimension, indicating that including any details about the environmental considerations would have made the talk far too long for the amount of available time. He said that achieving the purposes of the radiation protection system requires scientific knowledge, considerations about societal and economic aspects, and value judgements about different kinds of risk and balancing risks and benefits.
He acknowledged there are substantial uncertainties in the science. He told the audience that the uncertainties make the ICRP believe that the linear, no threshold (LNT) dose model is prudent, even if it overestimates the actual risk.
He made the following statement. (Time mark 14:30 in the audio file available at the bottom of this post.)
Prudence implies the duty of vigilance which means to relentlessly pursue research to try to reduce the uncertainties particularly as far as stochastic effects are concerned.
Aside: History does not provide any indication that radiation protection professionals have relentlessly pursued research to reduce uncertainties. There was little resistance from that community when the Department of Energy steadily reduced the funding for the Low Dose Radiation research program from about $20 million per year in FY2010 to zero in FY2014.
There has been little investment or political pressure to support research to reduce uncertainties in the dose response model from the international radiation protection bodies. End Aside.
Lochard then repeated the fact that the ICRP continues to assume that there is no threshold for stochastic (probabilistic) effects of radiation and that every dose, no matter how small, carries some amount of genetic risk to future generations. The organization believes that such a model leads to prudent protection measures and follows the well known medical profession ethic of “first, do no harm.”
I submitted the following question on one of the cards provided to the audience.
A model that overestimates risk might be conservative and prevent exposures through standards with margins of safety. Is it prudent, or ethical, to exaggerate risk after people have been exposed with a model that asserts hidden, undetectable damage that cannot be healed, treated or repaired.
My card made it to the top of the stack, so it was the first question asked. Don Cool, the meeting program chair, was assigned as the question reader added the following comment to my question.
Obviously there are some assumptions in there. I would take, and I am probably reading into this more than the questioner asked, the difference between a conservative approach prospectively and the use of conservative values when you actually have a particular individual and an exposure.
Here is how Lochard answered.
[Chuckled nervously] Well, I mean this is an endless debate. [Audience chuckles] We could try to elaborate on the distinction between precaution, conservatism and so on. Personally, I think that the system has to be used wisely. Which means that when you are dealing with trivial doses, you keep in mind they are trivial doses. When you are dealing with significant doses, you treat them with what they merit to be treated.
I said right from the beginning that the system is a combination of science, value judgement — social and ethical values, and experience. Experience is very, very important too. And I think by making decisions we have to combine these three components, what I call the three pillars.
If we just focus on science and discuss whether LNT is the right extrapolation but we also have radiobiology saying that maybe there could be some threshold for some particular situation, we go nowhere. The problem is action. Radiation protection is turned toward action. What do we do to protect people?
I think it’s very important that we recognize that there are uncertainties in our system, in the scientific basis of the system. It’s important that we try, as I mentioned, to reduce these uncertainties. This is the role of science. This is extremely important. It is a duty, a moral duty to always try to improve the scientific basis of our system. But as soon as we are in action, we have to act wisely and forget a little bit about all of the cooking of the science.
Mr. Lochard and other radiation protection professional should begin worrying about the lifetime of negative health effects from stress and a feeling of victimization that the LNT model imposes on people who have already been exposed to radiation.
If exposed people accept the model that the professionals have repeatedly promoted and defended ever since 1956, they must logically conclude that they are carrying the equivalent of a lottery card with some extremely negative consequences if their number comes up. That lottery never ends; they can never breathe a sigh of relief by finding out that someone else was the one who contracted cancer or passed on a genetic defect. They cannot make any lifestyle changes that will correct for the already received dose and any new dose they receive will simply make matters worse.
If they are trained radiation workers who had to accept a dose that is higher than current standards in order to correct a dangerous situation, they might never be allowed to work in their field again, even if the dose was still quite modest and did not result in any detectable damage.
Most distressingly, if they live in a culture that places a high value on genetic purity and generational equity, they might find themselves treated as outcasts and untouchables who should never have children. After all the LNT model asserts that they could be carrying an undetected and unrepairable mutation that could result in harm to future progeny.
The tragedy of the hibakusha in Japan following the atomic bombings of Hiroshima and Nagasaki was stimulated by acceptance of the genetic defect assumption; that human tragedy is repeating itself with the way that some victims of Fukushima are being treated by their society.
During Lochard’s talk, and those of others during the meeting, there was some consternation and concern expressed about the difficulty of helping people to get on with their lives after they had received a dose that professionals agree — amongst themselves — is trivial.
Those same professionals, however, do not seem to understand that it is perfectly logical for people who are not highly trained in statistics or probabilities to reason that they might be the one that gets the cancer or passes on a genetic defect. The fear and worry are caused directly from the assumption that there is “no safe dose” and that there is no recovery from any already received dose.
If you insistently tell people that there is no safe dose, you should not be surprised when they believe you. It should not be any surprise to radiation protection professionals that there is No Threshold For Fear.
The solution is obvious. Review all of the available dose response science without making an initial assumption that the LNT is correct.
If five or six decades of science that contradicts the linear hypothesis is not enough to persuade radiation protection professionals that their model is not conservative, but simply incorrect, then they should relentlessly pursue whatever research they believe is necessary to eliminate any remaining uncertainties.