“Acid Rain,” or more precisely acidic precipitation, is the term used to describe
rainfall that has a pH level of less than 5.6–a pH of 7 being neutral. This form of air
pollution is currently a subject of great controversy because of the damage it does tot he
environment and property worldwide. For the last ten years, this occurrence has brought
destruction to thousands of lakes and streams in the United States, Canada, and parts of
Europe. It also leads to the deterioration of buildings and statues by reacting with several
minerals. Acid rain is formed when oxides of nitrogen and sulfite combine with moisture
in the atmosphere to make nitric and sulfuric acids. These acids can be carried away far
from its origin.
The two primary sources of acid rain are sulfur dioxide (SO2), and oxides of nitrogen
(NOx). Sulfur dioxide is a colorless gas released as a by-product of combusted fossil fuels
containing sulfur (Farnham, http://www.ems.psu.edu/info/explore/AcidRain.html). A
variety of industrial processes, such as the production of iron and steel, utility factories,
and crude oil processing produce this gas. Sulfur dioxide can also be emitted into the
atmosphere by natural disasters or means (Farnham,
http://www.ems.psu.edu/info/explore/AcidRain.html). This accounts for ten percent of all
sulfur dioxide emission, coming from volcanoes, sea spray, plankton, and rotting
vegetation. Overall, 69.4 percent of sulfur dioxide is produced by industrial combustion.
Only 3.7 percent is caused by transportation (Farnham,
http://www.ems.psu.edu/info/explore/AcidRain.html).
The other chemical that is also chiefly responsible for the make-up of acid rain is
nitrogen oxide. Oxides of nitrogen is a term used to describe any compound of nitrogen
with any amount of oxygen atoms. Nitrogen monoxide and nitrogen dioxide are all oxides
of nitrogen. These gases are by-products of firing processes of extreme high temperatures
(automobiles, utility plants), and in chemical industries (fertilizer production)
(Phamornsuwana,
http://www.geocities.com/CapeCanaveral/Hall/9111/DOC.HTML#SPECIFIC). Natural
processes such as bacterial action in soil, forest fires, volcanic action, and lightning make
up five percent of nitrogen oxide emission (Phamornsuwana,
http://www.geocities.com/CapeCanaveral/Hall/9111/DOC.HTML#SPECIFIC).
Transportation makes up 43 percent, and 32 percent belongs to industrial combustion.
Nitrogen oxide is a dangerous gas by itself. This gas attacks the membranes of the
respiratory organs and increases the likelihood of respiratory illness. It also contributes to
ozone damage, and forms smog (Phamornsuwana,
http://www.geocities.com/CapeCanaveral/Hall/9111/DOC.HTML#SPECIFIC). Nitrogen
oxide can spread far from the location it was originated by acid rain.
Changes in environment change the wildlife living in that environment. The lowering
of pH from 7 to 4 is a dramatic change in environment, and the changes in wildlife reflect
it. There are both direct and indirect effects of acid rain. Acid directly interferes with the
ability of fish to take in oxygen, salt, and other nutrients needed to stay alive. Acidic
conditions in the water cause mucus to form in the gills of fish, and prevents them from
absorbing oxygen from the surrounding waters (Farnham,
http://www.ems.psu.edu/info/explore/AcidRain.html). With a few exceptions adult fish
are unable to survive in waters with a pH below 4.8. However, fish eggs and baby fish are
unable to survive pHs below 5.5 (Farnham,
http://www.ems.psu.edu/info/explore/AcidRain.html). If reproduction is not possible a
given fish population will eventually die off even if the pH is not low enough to kill the
adult fish. Most importantly, acid rain can harm us through the atmosphere or through
the soil from which our food is grown. Acid rain causes toxic metals to break loose from
their natural chemical compounds, thus making the previously harmless metals
dangerous. They release toxic metals that might be absorbed by the drinking water,
crops, or animals that humans consume. These foods that are consumed could cause
nerve damage to children or severe brain damage–aluminum is suspected to relate to
Alzheimer’s disease (Farnham, http://www.ems.psu.edu/info/explore/AcidRain.html).
One of the serious side effects of acid rain on humans is respiratory problems. The
sulfur dioxide and nitrogen oxide emission gives risk to respiratory problems such as dry
coughs, asthma, headaches, eye, nose, and throat irritation (Phamornsuwana,
http://www.geocities.com/CapeCanaveral/Hall/9111/DOC.HTML#SPECIFIC). Polluted
rainfall and fog is especially harmful to those with breathing problems such as asthma.
Acid rain can also aggravate a person’s ability to breathe and may increase disease
possibly leading to death.
The repairs on building and monuments can due to acid rain damage can be quite
costly. In Westminster, England, up to ten million pounds was dedicated to repairs
damaged by acid rain (Phamornsuwana,
http://www.geocities.com/CapeCanaveral/Hall/9111/DOC.HTML#SPECIFIC). In 1990,
the United States spent thirty-five billion dollars on paint damage (Phamornsuwana,
http://www.geocities.com/CapeCanaveral/Hall/9111/DOC.HTML#SPECIFIC). In 1985,
the Cologne Cathedral cost the Germans approximately twenty million dollars in repairs.
The Roman monuments cost the Romans about two hundred million dollars to restore
(Phamornsuwana,
http://www.geocities.com/CapeCanaveral/Hall/9111/DOC.HTML#SPECIFIC).
In 1991, the United States and Canada signed an air quality agreement. Ever since that
time, both countries have taken actions to reduce sulfur dioxide emission (Farnham,
http://www.ems.psu.edu/info/explore/AcidRain.html). The United States agree to reduce
their annual sulfur dioxide emission by about ten million tons by the year 2000 (Farnham,
http://www.ems.psu.edu/info/explore/AcidRain.html). A year before the agreement, the
Clean Air Pact Amendment tried to reduce nitrogen oxide by two million tons. This
program focused on the source that emits nitrogen oxide, automobiles and coal-fired
electric utility boilers (Farnham, http://www.ems.psu.edu/info/explore/AcidRain.html).
What humans can do, as citizens, to reduce sulfur and nitrogen dioxide emission is to
reduce the use of fossil fuels. Car pools, public transportation, or walking can reduce
tons of nitrogen oxide emissions. Using less energy benefits the environment because the
energy used comes from fossil fuels which can lead to acid rain. For example, turning off
lights not being used, and reduce air conditioning and heat usage. Replacing old
appliances and electronics with newer energy efficient products is also an excellent idea.
Sulfur dioxide emission can be reduced by adding scrubbers to utility plants (Farnham,
http://www.ems.psu.edu/info/explore/AcidRain.html). An alternative power source can
also be used in power plants to reduce emissions. These alternatives are: geothermal
energy, solar power energy, wind energy, and water energy.
Bibliography
Sarn Phamornsuwana (1999). Causes, effects and solutions of acid rain. Retrieved 9 Feb.
from the World Wide Web:
.
Shayne Farnham (1999). Acid rain: Meteorology independent study. Retrieved 27 Mar.
from the World Wide Web:
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