Thursday, April 24, 2008

It's Not Just Raining Cats and Dogs Anymore

Acid Rain

Acid rain is the result of a pollutant such as sulfur dioxide or nitrogen oxide reacting with water vapor in the Earth's atmosphere. This can then fall to the Earth as rain or snow (Spaulding & Namowitz, 2005).

As you may know, acidity is measured using a pH scale. Click here to see a pH scale. On the pH scale, substances are labeled with numbers to tell which are more acidic and which are more basic. The lower numbers mean a substance is more acidic. 7 is neutral, neither acidic or basic. Numbers higher than 7 indicate the substance is more basic (Spaulding & Namowitz, 2005).

Normal rain is just a little acidic - it has a pH of 6. This means it is 10 times more acidic than pure water. Scientists have discovered that acid rain that has fallen in the northeastern United States has a pH between 4 and 5. Since the pH scale is ten-fold, this means acid rain with a pH of 5 is 10 times more acidic than regular rain and the pH 4 acid rain is 100 times more acidic than regular rain or 1,000 times more acidic than neutral pure water (Spaulding & Namowitz, 2005).

Acid rain can damage plants and animals. Most life on Earth is pretty fragile and can only survive within a small range on the pH scale. This is the reason why lakes full of fish die due to acid rain. Acid rain also damages forests since it strips the nutrients from the soil. Remember, trees help absorb pollutants and greenhouse gases which lead to global climate change and acid rain. It is a vicious cycle. Acid rain can also eat away at marble and limestone structures (Spaulding & Namowitz, 2005). Check out these sites which will give you more information on the damaging effects of acid rain.
References

Decelles, P. (2002). The pH scale. Retrieved April 24, 2008 from http://staff.jccc.net/PDECELL/chemistry/Phscale.html
Science Master (2008). Environmental effects of acid rain.
Jump start earth science. Retrieved April 25, 2008 from http://www.sciencemaster.com/jump/earth/acid_rain.php

Spaulding, N.E. & Namowitz, S.N. (2005). Earth science. Evanston, IL: McDougal Littell.

United States Environmental Protection Agency (2008). Acid rain. Retrieved April 25, 2008 from http://www.epa.gov/acidrain/

United States Environmental Protection Agency (n.d.) Acid rain kids' site. Retrieved April 25, 2008 from http://www.epa.gov/acidrain/education/site_kids/index.htm

United States Environmental Protection Agency (2007). Effects of acid rain: materials. Retrieved April 25, 2008 from http://www.epa.gov/acidrain/effects/materials.html

United States Geological Society (1997). What is acid rain? Retrieved April 25, 2008 from http://pubs.usgs.gov/gip/acidrain/2.html

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