Setting air quality standards for carcinogens: an alternative to mathematical quantitative risk assessment — discussion paper

Abstract

1 It has been accepted in many countries that the regula tion of ambient air quality should involve the use of health-based air quality standards. 2 Setting standards for air pollutants which are genotox ic carcinogens presents difficult problems to the regu lator, in that the prediction of the effects on health of low levels of exposure is suspected to be inaccurate, and is not presently amenable to either experimental or epidemiological verification. 3 In some countries, techniques of Mathematical Quantitative Risk Assessment (MQRA) have been adopted to calculate acceptable levels of exposure to, or the unit risk factors for, genotoxic carcinogens. We regard these approaches as unsatisfactory. 4 An alternative approach, based upon a number of argued premises, a strategy which identifies decision points and the cautious application of uncertainty fac tors, is described.