Acid Rain If you have ever wondered why precious monuments are fading away, or the reason your car starts to look old, or if you can't understand why the bricks on the side of your house are breaking, look up the term Acid rain in your encyclopedia. Acid rain is the cause of all of this and much more. Acid rain is a widespread term used to describe all forms of acid precipitation (rain, snow, hail, fog, etc. ) (). Precipitation is naturally acidic because of carbon dioxide in the atmosphere. Acid rain begins with the production of sulfur dioxide and nitrogen oxides from the burning of fossil fuels, such as coal, natural gas, oil, and from certain kinds of manufacturing.

Sulfur dioxide and nitrogen oxides react with water and other chemicals in the air to from sulfuric acid, nitric acid, and other pollutants (). What was once a local problem for towns and cities is now an international problem. The spread of this problem originated from tall chimneys dispersing pollutants high into the atmosphere, which then traveled with the wind for thousands of kilometers until once again reaching the ground in an invisible state. The effect of acid rain when it reaches the ground reacts chemically with any object it comes in contact with. Acids are corrosive chemicals that react with other chemicals by giving up hydrogen atoms (). The acidity of a substance comes from the abundance of free hydrogen atoms when the substance is dissolved in water ().

Acidity can be measured using a 'pH's cale with units from 0 to 14. Rain (snow, fog, etc. ) measured at a pH below 5. 6 is considered acid rain.

Acid rain is responsible for a widespread of environmental damage. Such examples of this include soil and plant degradation, depleted life in lakes and streams, and erosion of man-made structures (). When acid rain enters the soil it dissolves and washes away the nutrients needed by plants. It can also dissolve toxic substances, such as aluminum and mercury, which are naturally present in some soils, freeing these toxins to pollute water or to poison plants that absorb them (). After events like this take place animals and humans are soon effected. If one plant or animal is adversely affected by acid rain, animals that feed on that organism may suffer and animals that feed on that animal may suffer also (usually humans).

The end result could be an entire ecosystem becoming endangered. There has already been plenty of damage done by acid rain. There has been as many as 10, 000 lakes in Sweden polluted by mercury released from soils because of acid rain (). In air acids join with other chemicals to produce urban smog, which can irritate the lungs and make breathing difficult, especially for people with pre-existing respiratory problems.

Acid rain in most all cases is a horrible thing and we need to do something to slow the process. Acid pollution does have one beneficial effect though. Sulfates in the upper atmosphere reflect some sunlight out into space, and thus tend to slow down global warming ().