Air pollution damage estimates: the cost per kilogram of pollutant

To optimise environmental regulations such as emission limits, pollution taxes or tradable permits, it is necessary to know the damage cost per kilogram of emitted pollutant. It is calculated by means of an impact pathway analysis which involves the calculation of the increased pollutant concentration in all affected regions due to an incremental emission (e.g. µg/m² of particles, using models of atmospheric dispersion and chemistry), followed by the calculation of physical impacts (e.g. number of cases of asthma due to these particles, using a concentration-response function) and multiplication by the corresponding cost. The numbers are summed over all receptors (population, crops, buildings, and so on) of concern. We show that in a uniform world (linear dose-response function, uniform receptor density and uniform atmospheric removal rate) conservation of matter implies a very simple formula for the total damage. The generalisation to secondary pollutants is straightforward. By detailed numerical evaluation, using real data for atmospheric dispersion and geographic receptor distribution, we demonstrate that this simple formula is an excellent representation of typical damages. Results are shown for the principal air pollutants emitted by smokestacks at industrial installations or by road transport.