ABSTRACT
In our pollution analyses we have so far considered discharges as deterministic variables. Furthermore, we have assumed that the effects of discharges on environmental indicators can be predicted with certainty. In many actual situations, on the other hand, it would be realistic to assume that both discharges and effects on the environment of given discharges are stochastic variables. Discharges ‘measured at the factory gate’ may be stochastic on account of random variations in the course of production and/or purifying processes due to mechanical defects, accidents, and the like. Discharges reaching recipients may vary at random as a result of weather conditions. As far as the relationship between discharge reaching the recipient and ‘environmental service production’ measured in terms of the value of environmental indicators are concerned, these can also be affected by wind and weather conditions. Damage caused by discharge to a river may depend on the water level; wind and precipitation will also have a bearing on the effects in the actual recipient of supplies of given quantities of discharge. An example that springs to mind is the formation of photochemical smog.
