acid rain

            Acid rain may possibly be the leading cause of death in North America. Of course, this statement does not directly refer to human mortality, but to the mortality of forests and the plants that inhabit them. This rapid deforestation creates a loss of habitat for forest dwelling animals, which ultimately leads to further loss of life. Even if this destruction does not mean imminent peril for the human population, it will certainly mean a reduction in the quality of life for all of us. The purpose of this report is to describe the causes and implications of acid deposition, or as it is more commonly known, acid rain.
             Although rain is the most recognized form of acid deposition, it may also come in many other forms such as snow, sleet, hail, fog, or dry particles. Dry particle deposition accounts for about half of all acid deposition. Acid deposition occurs when sulfur dioxides (SO2) and nitrogen dioxides (NOx) are emitted from the burning of fossil fuels and released into the atmosphere. These acids then fall to earth in dry form or combined with water molecules to form acid precipitation (rain). The acidity of these depositions is measured using the pH scale. The pH scale is a logarithmic scale ranging from 1 to 14, with 1 being the most acidic, 14 being the most caustic, and 7 being neutral. Pure water has a pH of 7. Normal rain is slightly acidic because of the carbon dioxide that naturally dissolves into it, so it has a pH of about 5.5. As of the year 2000, the most acidic rain falling in the US has a pH of about 4.3. (1).
             Almost all of the electricity that powers modern life comes from the burning of fossil fuels such as coal, natural gas, and oil. The burning of coal accounts for almost all of the SO2 emissions, because sulfur is found as an impurity in coal (1). NOx is released when any fossil fuel is burned, but automotive emissions are the largest source of the over-abundance of nitrogen dioxide in the atmosphere.