find it’s way to the city’s water when acid rain comes in contact with the
cement. Effects On Man Made Structures Scientists are becoming increasingly
concerned with acid rain’s destruction of the ‘built environment’. There are
objects in our built environment that are irreplaceable. Historic landmarks and
statues, old cathedrals and temples, paintings and sculpture – all are part of
the built environment and are slowly being damaged. Some of these objects are
practical, making life easier, safer or more comfortable. Many factors determine
how much damage acid rain will do, including the amount of rain, the location,
and direction of wind. All influence the amount of corrosion done. Areas that
have a large amount fog or humidity tend to suffer more than dry areas, which is
why many steel bridges located over water get rusted and corroded by acid. When
metal is decayed, it cannot take the same amount of stress of weight as when it
was originally created. Acid rain has been blamed in several collapses of
bridges around the world. Acid rain corrodes the steel track used on railroads,
thus the tracks must be constantly checked. Metal in air planes can also be
eaten away by acid rain. The United States Air Force spends more that $1 billion
every year to repair or replace damaged parts.6 A study done in Sweden showed
that metal rusts four times faster in areas that receive a lot of acid rain.
This figure is staggering, and yet, metal is not the only material damaged by
acid rain. Houses and buildings made of brick and stone are affected as well.
Acid rain can dissolve the mortar, which is used in cement to hold bricks
together. When the mortar is worn away, the bricks crumble more easily, because
they shift and cannot stay intact against the heavy weight of the bricks
pressuring from above. The corrosive effects of acid rain are particularly
obvious on limestone, because it is composed of calcium carbonate, which is
highly reactive with acid rain. Tombstones made of marble (which is
metamorphosed or heated limestone) have been badly damaged, while older
tombstones made of slate remain intact. Famous buildings such as the Taj Mahal,
The United States Capitol building and the Lincoln Memorial in Washington, are
all being continually damaged by acid rain. Statues made of bronze and copper
are particularly susceptible to corrosion. These statues turn green naturally,
and this covering, called a patina, acts as a protective shield against the
elements. Acid rain eats away at the patina, and where the acid dissolves the
green covering, it leaves a streaky black coat. This process ruins statues
throughout the world. How Does Acid Rain Affect the Economy? Canada/American
Relations Canada is particularly susceptible to the effects of acid rain. Its
geographical location places it directly in the path of a large amount of U.S.
emission, and the granite bedrock of the Canadian Shield has a poor buffering
quality. (A buffer is a material that can chemically weaken acid soil and is
less harmful to the environment, such as lime or baking soda.) The lack of such
a quality renders Eastern Canada highly vulnerable to damage due to United
States pollution. Canada suffers more from acid rain than the United States
does, even though much of the pollution originates in the United States. Acid
rain costs Canadians hundreds of millions of dollars every year. To try and
decrease the large amounts of money the pollution is costing tax payers, Canada
has passed laws to force its electrical companies to cut down on harmful
emissions. However, no matter what laws are passed in Canada, it is not possible
to stop U.S. power plants from sending acid in its direction. Figure 1-3
displays amounts of emissions created by the United States and Canada. The Gavin
power plant is an excellent example of how the United States sends tonnes of
acid to Canada every year. Every hour, this power plant burns 600 tonnes of
coal. The higher the smokestack, the further the dangerous gases will travel,
and the Gavin smokestack is 1 103 feet tall.7 Obviously, The Gavin can not be
solely blamed for the pollution, but it is power plants such as these that have
caused trouble between the two countries. It is estimated that about 50% of the
sulfate deposited in Canada derived from American sources.8 Sixty of the largest
plants and thus largest polluters are located in the Ohio Valley, a short
distance away from vulnerable Canadian land. In 1980, Canada and the United
States signed a Memorandum of Intent, an agreement that both countries would
make acid rain control a priority. They both promised to focus on developing
ideas to cut down the amount of sulfur dioxide and nitrogen oxide emissions
being pumped into the air. In the past, Canada has presented devastatingly large
figures to the United States, in an attempt to have them change laws and
regulations regarding pollution. Unfortunately, the attempts thus far have been
unsuccessful, as the US government requests more testing and studies instead of
altering laws. In the recent past, the negotiations between Canada and United
States representatives have been hardly reminiscent of efforts put forth by
Canadian officials. Many U.S. politicians still qualify acid rain as a ‘minor’
problem, and it is treated as such, according to Raymond Robinson, chairman of
the Canadian Environmental Assembly.