Environmental Engineering Reference
In-Depth Information
Figure 4.5
The geography of acid rain, showing areas with pH below 5.0
Source:
After Park (1991)
the auspices of the World Bank has been designed
to change that. The study will be based on a
computer model called RAINS similar to one
developed by the International Institute for
Applied Systems Analysis for the European
Community. Results from the model will allow
researchers to alert Asian governments to the
extent and intensity of the acid rain problem, and
to recommend ways of dealing with it (Hunt
1992).
Acid emissions remain limited outside the
major industrial nations, but concern has been
expressed over growing levels of air pollution
which may already have provided a base for acid
rain in some Third World countries (Park 1987).
The future extent of the problem will depend
upon the rate at which these countries
industrialize, and the nature of that
industrialization. Experience in the developed
world shows that other possibilities exist also.
For example, large conurbations—such as Los
Angeles—with few sulphur producing industries,
but with large volumes of vehicular traffic, have
been identified as sources of acidic pollution (Ellis
et al.
1984). Many developing nations are
becoming rapidly urbanized, and, as a result, may
provide increased quantities of the ingredients
of acid rain in the future (Pearce 1982c). Thus,
although at present the geographical distribution
of acid rain is largely restricted to the
industrialized nations of the northern hemisphere,
it has the potential to expand to a near-global
scale in the future (see Figure 4.5).
All of the areas presently producing large
amounts of acidic pollution lie within the mid-
latitude westerly wind belt. Emissions from
industrial activity are therefore normally carried
eastwards, or perhaps northeastwards, often for
several hundred kilometres before being
redeposited. The distance and rate of travel are
