Environmental risks: scientific concepts and social perception.

Using the example of air pollution, I criticize a restricted utilitarian view of environmental risks. It is likely that damage to health due to environmental pollution in Western countries is relatively modest in quantitative terms (especially when considering cancer and comparing such damage to the effects of some life-style exposures). However, a strictly quantitative approach, which ranks priorities according to the burden of disease attributable to single causes, is questionable because it does not consider such aspects as inequalities in the distribution of risks. Secondly, the ability of epidemiological research to identify some health effects is limited. Third, the environment has symbolic and aesthetic components that overcome a strict evaluation of damage based on the impairment of human health. It is not acceptable that priorities be set just balancing the burden of disease caused by pollution in the environment against economic constraints. As an example of a computation that inherently includes economic analysis, I refer to the proposal of an estimator of mortality in coal mining, i.e., a rate which puts deaths in the numerator and tons of coal extracted in the denominator. According to this estimator, mortality due to accidents decreased from 1.15 to 0.42 in the period 1950-1970 in the United States, for each million tons of coal extracted. However, considering the steep decline in the workforce in the same period, the traditional mortality rate (deaths over persons-time) actually increased. The proposal of a measure of mortality based on the amount of coal extracted is just one example of the attempts to influence decisions by including an economic element (productivity) in risk assessment. This paper has three purposes: One, to describe empirical research concerning the health effects of environmental pollutants; two, to discuss the scientific principles and methods used in the identification of environmental hazards; and three, to critically discuss some of the ethical principles which are applied in medicine and in the assessment and management of risk.