This is the age of ecology when we have at last realized that the state of our
environment matters and that maintaining a healthy environment carries a price -
often a very high one. We are beginning to assess that price and to brace ourselves to
meet it. But before we can make the cost-benefit assessment we must first decide
‘what is a healthy environment’?
I know of no example of ‘environmental pollution’ that does not have some
positive aspects, but there is usually a strong consensus in favour of avoiding
extremes. Thus, when the UK Clean Air Act removed visible air pollution in the UK
during the 1960s and 1970s, gardeners and horticulturalists noted a massive increase
in the level of plant disease (both fungal and aphid) and this is said to have led to a big
increase in the need to use pesticides and fungicides in urban gardens. Nevertheless,
few would dispute the majority view that the Clean Air Act was a very good statute
for environmental protection. Similarly, only interested industrialists dispute the
need to decrease or control the levels of industrial pollution of river water.