Air Quality and Health and Welfare

2.10 Methodologies and State of the Art for Quantifying the Health Impacts of Air Pollution

2.10.1 Introduction
As discussed in earlier sections of this chapter, air pollution can have a wide range of impacts. These impacts can vary from ugly vistas and reduced visibility to impacts on natural systems and human economies to increased illness and death in the human population. The main point of most air quality management programs is to reduce or eliminate these negative impacts. However, the reduction or elimination of these impacts almost always requires modifications to human economies and the lifestyle of the human population. Thus, there is almost always some debate about the balance between air quality management efforts and the need to main the existing economy and lifestyle. Policy makers and air quality managers are often confronted with the need to make these types of evaluations in society. The science of estimating air quality impacts has evolved out of this process.

In order to make comparisons between the different types of impacts, a common metric must be found for making these comparisons. For example, how is the loss of a job that is providing support for a family compared to reducing the illness of a child that is caused by air pollution. Or, how is the improvement in visibility in a region compared with the inability to by a new television. The feelings on these tradeoffs naturally vary with who is being impacted and the value systems that the impacted persons hold. Thus, there can be much debate on the issue.

The metric that is most often chosen to compare these widely varying issues is cost. All impacts to be debated are reduced to a cost basis and then compared with this common metric. This of course, unfortunately, requires that values be placed on vistas, wildlife, lifestyle, human health, and ultimately the worth of a human life. Economists and other scientists have carried out much research with respect to the evaluation of the variety of impacts due to environmental degradation, illness, loss of life, and impacts to the economy. It is this research that air quality managers must turn to when faced with the need to debate the tradeoffs between air quality improvement and changes in the economy.