Risk Based Approaches to Assessing the Environmental Burden of Acid Gas Emissions

This paper discusses simple risk-based ways of choosing locations where reductions in airborne emissions should be made, based on exceedences of environmental objectives. A major regulatory issue is how emissions should be managed within national emission limits, at the same time minimising exceedences of environmental objectives. As air quality models become more detailed, complex environmental optimisation becomes harder to manage. At the same time decisions involve other qualitative factors besides meeting air quality standards alone. In this paper a practical method is introduced for dealing with the risk posed by acid and nutrient deposition and exposure to particles based on describing the source-receptor relationship in terms of a Green’s function. The aim of the research is to produce a map (or maps) showing the relative importance of source locations for emissions from a specific type of source. The method allows one to decide where would be the best place to reduce current emissions. The examples are chosen to illustrate the approach to environmental decision making and in later examples show how social/demographic factors may be taken into account.