Discounting in assessment of future radiation effects

Abstract

There is a question as to whether cancer fatalities to be experienced in the distant future as a result of radioactivity produced today should be treated on a par with those experienced now, or whether there should be discounting in analogy with accounting principles for money to be spent in the future. It is shown that recent trends in cancer cure rates justify about an 0.7% per yr discounting. Other rationales for discounting are developed. Money can, and always will be usable for saving lives; setting up a trust fund far future generations to use for this purpose is much more cost-effective than spending money now to reduce their exposure to radiation. The history of interest rates over the past 5000 yr indicates that at least 3% real annual interest can be expected. It may not be necessary to actually set up a trust fund as its purpose is largely accomplished by the decrease in the public debt when money is not spent. The trust fund approach is mathematically equivalent to discounting lives lost in the far future at 3% per yr. As an alternative to the trust fund, money can be invested in biomedical research. It is shown that per dollar spent, this is usually far more beneficial to the health of future generations than protecting them from radiation as that art is currently practiced, and for purposes of cost-benefit analysis, it corresponds to discounting lives lost in the future by a factor of the order of the number of years before they are lost; e.g. The number of lives calculated to be lost 1000 yr from now should be divided by 1000. Implementation of the biomedical research alternative requires only that about 0.1% of taxes from nuclear plants and 0.1% of government support for biomedical research be re-defined as contributions from nuclear plants to this research. © 1983 Health Physics Society Pergamon Press Ltd.