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			Acid Rain Naval Meterological and Oceanography Command 03.19.01 The atmosphere is like an enormous chemist's beaker - a vessel where gases mix, mingle, and react, often turning into poisonous substances capable of returning to earth as rain or snow. Acid rain has been blamed for the "death" of several lakes and rivers in North America and may be responsible for world-wide forest depletion as well. 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. A substance's pH factor, a figure on a scale of 0 - 14, determines a substance's acidity. A pH value of 7 is average. A figure less than 7 indicates higher acidity, more than 7 greater alkilinity. Rainfall with a pH lower than 5.6 is considered abnormally acidic. 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 young. 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. Some scientists think that acid rain affects forest growth by weakening trees so that they are less likely to survive droughts, insect attacks, diseases, or storm damage. Natural habitats are not the only ones endangered. Man-made office buildings, houses, and automobiles also erode due to repeated soakings of acid rain Several government agencies are currently investigating acid rain. They are expected to recommend technology which will clean up sulfur emissions made by factories


			Naval Meterological and Oceanography Command Public Affairs Office 1100 Balch Boulevard Stennis Space Center, Mississippi 39529