Atmospheric pollutants and air quality effects: limitation costs and environmental advantages (a cost–benefit approach)

In order to improve the air quality in some very critical areas in Europe, it is required to limit the contaminant flux coming from different sources (thermal and industrial plants, transport systems, cars, and other technological apparatus). This limitation in many cases corresponds to important investment costs, and normally to a substantial increase in the operative costs; but, from the other side, by the intervention on the emitted pollutant loads it can be obtained a condition of better air quality, with consequent lower externality costs, chiefly with reference to the exposed population. By comparing the two aspects of increasing costs, and in particular the slope of the increasing trend, and from the other side the improvement in air quality, it is possible to identify as a compromise a convenient definition of the optimal intervention that must be realized, and it is possible to establish the performances that must be obtained, by arriving to an acceptable air quality with a sustainable cost. This strategy of identification of the optimal point between these two opposite trends has been illustrated in the present work, and some practical examples of implementation of different limitation strategies and consequent environmental results are presented; these results concern different scale solutions, and different geographic situations.