Geoscience Reference
In-Depth Information
problem in this fast-growing region of the world, with China
'
s coal-burning power
plants a major source of sulphur dioxide emissions.
After the Second World War, air pollution problems associated with mass car
ownership began to accelerate,
rst in the developed and then in the developing
world. Emissions of nitrogen oxides from automobile exhausts are a signi
cant
source of acid rain. And until recently, vehicle exhausts spewed millions of tons of
toxic lead into the atmosphere (tetraethyl lead was used as an additive in petrol to
help the engine run smoothly), impairing the normal intellectual development of
children in urban areas. Other vehicle pollutants known to have direct or indirect
adverse effects on human health include carbon monoxide, sulphur dioxide,
ne
airborne particulates and volatile organic compounds (VOCs) such as benzene,
which contribute to the increase or severity of cardio-respiratory conditions and
even pose a cancer risk to city dwellers.
51
Studies have shown that children and the
elderly are particularly at risk from exposure to these pollutants. Somewhat ironi-
cally, from the mid-1950s smoke control initiatives in Western cities allowed more
sunlight to penetrate to the streets, where it reacted with pollutants such as VOCs
and nitrogen oxides emitted from vehicle exhaust pipes to form dangerous ozone-
laden photochemical smog. Excessive ozone in the air can cause breathing prob-
lems and trigger asthma attacks. But laws that controlled smoke in urban areas did
not cover less visible emissions from cars (initially thought to be a minor issue in
comparison with industrial sources of pollution). The rapid rise of automobile-
centred transport systems
—
with high levels of individual car use
—
led to an air
cult to control.
52
Concerns about the effects of air pollution from automobiles on human health
pollution problem that was dif
as its
residents began to complain of smarting eyes and a wide range of respiratory
ailments. Suggested measures to limit exhaust emissions proposed during the
1950s, as vehicle ownership in California topped 7 million, included encouraging
car pools, prohibiting car use at certain times in certain places, and imposing a
'
rst emerged as early as the 1940s in Los Angeles
—
a city built for cars
—
tax on drivers.
53
However,
s personal
freedoms, and that increased the cost of motoring, unsurprisingly proved to be
unpopular with the public
smog
'
'
solutions
'
that infringed on people
'
c pollution problems
were emerging elsewhere in the world, with, for example, photochemical smog
episodes in Athens, Greece, (called nephos locally), rivalling those of Los Angeles
and damaging both human health and its historic buildings. At the turn of the
twenty-
—
then and now. By the 1970s, traf
rst century, there were around 600 million cars registered worldwide,
200 million of them in the United States alone. But as car ownership has risen
sharply in the developing world, places like Bangkok, Buenos Aires, Mexico City
and Mumbai now rank among the most heavily polluted
. Globally,
there has been a tendency for older, more polluting cars to be exported from the
'
smog cities
'
51
Read (
1994
) and McMichael (
2001
).
52
Read (
1994
), Elsom (
1992
), Dupuis (
2004
) and McNeill (
2000
).
53
Elsom (
1992
) and Rajan (
2004
).
