ANS National
 Meetings/
 Sessions

November 1995

Jerry J. Cohen

(Cohen Consult)

3. Rethinking ALARA

                "The recommendation to keep exposures to ionizing radiation 'as low as reasonably achievable' (ALARA) has been a long-standing component of radiation safety programs. This recommendation is based on the assumption that there is no dose threshold below which harmful biological effects will not occur. With this assumption, it logically follows that there is no 'safe' level of exposure and that any exposure, no matter how low, carries with it some risk of harm. This presumption was a departure from a previously established principle in public health that could be paraphrased 'the dose makes the poison,' which held that high-dose effects of harmful agents are not necessarily indicative of low-dose effects. The concept of further minimizing radiation exposures to levels well below specified dose limits originated in the 1950s with the Inter- national Commission on Radiological Protection (ICRP) recommendation that doses be kept 'as low as possible' (ALAP). In 1959, ICRP replaced 'possible' with 'practicable,' and in 1973, ALAP was changed to ALARA to convey ICRP's intent to achieve dose minimization with 'economic and social considerations being taken into account.' To implement this guidance, ICRP recommended application of cost-benefit analysis to balance economic costs against benefits of dose reduction."

                "Implementation of ALARA in radiation protection programs is a regulatory requirement in the United States; however, ICRP recommendations on use of cost-benefit analysis are largely ignored. Under U.S. Nuclear Regulatory Commission (NRC) rules, required ALARA programs can essentially be defined as 'dose reduction' programs. A cursory survey of nuclear installations in the United States revealed numerous instances of 'ALARA horror stories' where ALARA is the cited basis for making enormous expenditures to achieve relatively trivial levels of dose reduction. This observation has led to a questioning of the basic premises upon which ALARA is founded.

                "ALARA is clearly predicated on the assumption that there is no threshold below which biological effects are nonexistent or possibly even beneficial in nature. This assumption has been used as a basis for regulatory decisions for so long now that it has come to be regarded by the public as an immutable truth. However, there is currently a considerable body of evidence indicating that the assumption is false. This evidence has been largely ignored in the regulatory decision-making process for the stated reason that it is 'not convincing.' Because, at very low doses, it would be statistically impossible to prove the occurrence of any effects (either harmful or beneficial), it is highly unlikely that clear, absolute proof will ever be gained. However, the preponderance of direct low-dose (< 100 mrem/yr) evidence that does exist indicates that beneficial effects would be more likely.

                "The argument may be made that even if the no-threshold assumption is wrong, it still provides a 'prudent' basis for regulatory decisions. If, in fact, low-dose radiation exposure produces no adverse effects, then accepting this assumption as a basis for regulatory decisions is certainly not prudent. The resulting policies can and have caused the expenditure of vast amounts of limited resources toward meeting requirements that produce no public benefit. These resources necessarily become unavailable for other areas of public health and safety where they might actually do some good.

                "It may also be argued that highly restrictive regulation, as is the case with the NRC's ALARA requirements, can be justified as a reflection of inordinate public fears toward radiation. On the other hand, a strong case may also be made to the effect that such regulatory policies are a major cause for those fears, because it could logically be inferred that severe controls would be unnecessary if radiation was not extremely dangerous.

                "Despite the existence of scientific evidence indicating the likelihood that ALARA is technologically unfounded, one should not be optimistic that current policies will be relaxed. Considering the deep-seated public fear of radiation (regardless of dose level), such relaxation would likely prove to be politically unpopular. It is also unlikely that the idea that ALARA is an unsound policy would gain widespread acceptance among radiation protection professionals, because it is estimated that >50% of this group is gainfully employed in work that is directly or indirectly related to ALARA. Nonetheless, from a public health standpoint, ALARA is at best a highly questionable policy that should be subjected to an objective and unbiased reassessment in light of all current evidence on low-dose radiation effects. A serious problem in this regard might be the assembly of a knowledgeable group of experts to review ALARA policies, who have no vested interest in its perpetuation."