Each day, thousands of tons of sulfur and nitrogen oxides are pumped into the air by fossil fuel burning plants and automobile exhaust systems. Sunlight converts these gases into sulfuric and nitric acids which then are absorbed by the water particles in clouds. Mixed with rain and snow, they fall back to earth, usually hundreds of miles from the original source of the pollution.The term acid rain is somewhat misleading. In addition to the "wet" substances of rain, snow, and fog, dry particles of sulfur and nitrogen oxides also fall and are absorbed by plants and soil. These particles, known as acid deposition, turn acidic when mixed with surface moisture.Acid rain releases aluminum from soil into the rivers and lakes restricting the growth of aquatic plant roots. Aluminum also clogs the gills of aquatic animals, attacks calcium in their bodies, and causes life-threatening deformities in their offspring.As plants, insects, fish, amphibians and reptiles disappear, the structure of the lake's ecosystem weakens and collapses. When the lake is completely unable to support life, mammals and birds which rely on the lake as a food source become endangered. Sadly, "dead" lakes and streams often appear clear and beautiful.
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