Environmental Engineering Reference
In-Depth Information
It is likely that the main value of smog inspection systems is that they
allow the detection of the relatively small number of cars and trucks that
are responsible for a disproportionate share of vehicular emissions. A study
conducted by the National Research Council reported in 1991 that 50 per-
cent of the ozone-forming emissions from mobile sources come from fewer
than 10 percent of the vehicles in operation. Getting these “gross polluters”
into compliance (or off the road, if this is not possible) may be the most
cost-effective way of reducing automotive emissions.
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The issue of cost effectiveness must be faced squarely in any serious dis-
cussion of emissions control.
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Government-mandated technological fixes
have added hundreds of dollars to the cost of a car, while the costs of Cal-
ifornia's inspection program and required repairs come to about $500 mil-
lion annually. In return, Southern California has benefited from cleaner air,
but the region is still not in compliance with federal standards, and more
drastic (and expensive) measures may be required in the years to come.We
are well past the point where the installation of simple devices like PCV
valves, and even complex ones like catalytic converters can effect substan-
tial improvements. It is likely that diminishing returns have set in with
regard to the benefits obtained from anti-pollution expenditures.
At the same time, there is no easy consensus in regard to additional
expenses that should be borne in pursuit of cleaner skies.There is some evi-
dence that air pollution in Southern California is associated with higher
risks of bronchitis and asthma,
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but it can always be argued that all good
things, such as the personal mobility afforded by the automobile, will have
some unfortunate consequences. Greater precision can be brought to the
issue by conducting cost-benefit analyses that attempt to put a monetary
value on the illnesses engendered by air pollution, but carrying out a pre-
cise epidemiological study would be a very difficult task, given the many
factors involved in ill health, as well as the continual movement of people
into and out of Southern California. And there is simply no way to put a
dollar value on the ability to see the mountains or to play a game of tennis
without feeling that one's lungs are being reamed out.
The complexities of cost-benefit analysis aside, there can be no question
that the skies over Southern California are much better than they were
before the effort to build cleaner cars was launched. Reduced levels of air
pollution show that some problems can be successfully addressed through
the application of one or more technological fixes. Smog pollution has been
