ABSTRACT
It has been claimed that ‘the solution to pollution is dilution’. Tall chimneys operate on the ‘safe dilution’ approach to discharges to the envi-
ronment. For example, pollution from the nickel smelting works at Sudbury, Canada, caused severe ecological disruption to the surrounding countryside. The ‘solution’ was to increase the height of the chimney so that metal particulates were carried further from the factory. Although the total amount of pollutants discharged remains the same, the concentration locally has markedly reduced, so that plants have begun to recolonize the vicinity of the factory, but the ‘solution’ has added to the acid rain of eastern North America.
