Acid Rain Essay, Research Paper
ACID DEPOSITION
Picture a cancer, eating a human, a sister, a brother, away bit by bit. Destroying every organ, slowing every heart beat, weakening every muscle. Then finally, shutting the body down. Ending it?s existence. Acid deposition is the earth?s cancer. Every rain drop causing massive destruction throughout the world. Every downpour, killing another lake, stream, fish, tree, or human. Every smog, killing it?s inhabitants, weakening it?s life. Unlike many environmental problems, including CFCs (chlorofluro-carbons), which directly destroys the ozone, it?s effects touch more than just one thing directly. The precipitation, and the dry deposition kill or weaken anything and everything it touches. It can also effect everything indirect, as the chemicals and acids stored in the rain are transferred through leaves and soil to roots and lakes from runoff. This is the silent killing it performs, with obvious effects, and so close to home. Believe it or not, but Canada receives a lot of the acidic deposition. The Canadian government has even dubbed the problem, the most pressing environmental issue facing the nation. The United States is mainly to blame for this domestic epidemic. The United States creates over 130 million tons of sulfur dioxide (50 to 70% of overall sulfur dioxide emissions in Canada come over the border from the United States) , which is transported through the air to Canada, where it kills our lakes, our rivers, our trees, and our wildlife. Even though emissions have been cut down in Canada by 30%, the US still manages to produce millions of tones of harmful chemicals which end up polluting our nation, our home. Acidity, the pH scale, and measurements To understand what makes precipitation acidic, one must understand what an acid is and how it is measured. The acidity or alkalinity of a substance is measured on a potential hydrogen (pH) scale. This measures the amount of hydrogen ions in a substance. The more hydrogen ions, the lower the pH level. A reading below 7 indicates an acid, therefore one above 7 indicates a base. Clean, unpolluted precipitation is naturally acidic, with a pH of 5.6. When precipitation with pH levels lower than 5.6 fall, the number of hydrogen ions in the soils and plants increase, upsetting their natural balance, killing all life. Rain, in Pitlochry, Scotland, has been tested with pH levels as low as 2.4, almost that of lemon juice. The pH levels of acid deposition have been strong enough to wipe out whole lakes of water species. What is Acid Deposition? Acid deposition, by definition, is “the transfer of acids from the earth?s atmosphere to its surface.” This is done two ways: acid precipitation and dry deposition. Acid Rain, the most popular form of acid precipitation, attracts most of the attention of the media, and most environmentalist groups, but it isn?t the only form of acid precipitation there is. The acids can be transferred through acid fogs, acid sleets, acid snows, acid hails, acid fogs, and through acid mists. It is the biggest culprit when it comes to the damage caused by acid deposition. The other form of acid deposition, is very common, yet unknown to many environmentalists. Dry deposition, is the falling action of acidic particles (mainly sulfur dioxide, nitric oxide, and nitrogen oxides) during dry periods. Examples of such would be smog. Both examples contribute equally to the destruction of the earth?s environments and inhabitants. Causes Acid deposition is the result of smoke emissions from fossil fueled power plants, oil refineries, (such as Inco, Algoma Steel, and Falconbridge). It is also the result of every single person, who drives or rides a vehicle to work everyday. An unfortunate fact being that 90% of the sulfur dioxide and 95% of the nitrogen oxide emissions occurring in eastern North America are of human origin. “The burning of fossil fuels, such as coal and oil are largely to be blamed for half of the emissions of this gas (sulfur dioxide) in the world.” These environmental felons kill life everyday. Acid deposition is caused by the emissions of nitric oxide (NO), nitrogen oxide (NO2) and sulfur dioxide (SO2) into the atmosphere. These gases are emitted by natural sources such as volcanoes, sea spray, rotting vegetation, and plankton, but the amounts are not substantial enough to cause precipitation with pH levels that low. Acid precipitation is caused when emissions containing sulfur dioxide, nitric oxide, and nitrogen oxide, combine with moisture in the air to form acid precipitation. When combined with water, they complete a chemical formula, one that represents destruction and devastation. Dry Deposition is the particles of the chemicals themselves suspended in the air. Effects on the Environment All forms of acid precipitation damage all kinds of vegetation. The problems caused by it are numerous and in most cases cause death, whether it be a tree, shrub, lake, stream, or fish. The effects, though, depend on weather conditions, humidity, sunlight , presence of other pollutants, length of time the pollutants have remained in the atmosphere, and buffering capacity . They also depend on contact with: ? Primary receptors – come into direct contact with pollutants (e.g. building, trees, plants, etc.). ? Secondary receptors – come into contact after they?ve come into contact with other materials (e.g. foliage of plants, soil beneath vegetation, etc.). ? Tertiary receptors – indirectly affected (e.g. subsoil, bedrock, watercourses and lakes). All effects may come in combinations, separately, or all at once. Effects on crops Scientists have now received evidence that proves that acid deposition greatly effects agriculture, along with everything else. One some croplands, tomatoes grow to only half their full weight and the leaves of radishes wither. Nitrogen oxide is the culprit responsible for $2 billion to $4.5 billion worth of wheat, corn, soybeans, and peanuts. This decrease can hurt 3rd world countries, and augment the price of food worldwide. Thousands of people could starve due to this new scientific discovery. Effects on Forests A young man kills someone with his bare hands, and citizens cry out in rage. They say they will do anything to prevent him from hurting another, killing another. Yet silently, everyday, vegetation is weakened, threatened and killed, far away or close to their homes, and they sit back and watch. Scientists have known for twenty years now the effects that acid deposition has on the forests. The forests themselves grow thinner, and slower, than their predecessors, due to the damage it has caused. Coniferous tree needles die-back , their growth is stunted, they loose their resistance to disease and drought, and they experience a lack of natural regrowth. Deciduous trees, on the other hand, grow discolored or misshapen leaves, experience early leaf fall, have dead tree tops and/or damaged bark, loose their resistance to drought and disease, and experience a lack of natural regrowth. The loss of feeder roots and smaller tree rings are also effects. Basically, the forests are slowly dying off. Forests in high mountain regions receive additional acid from the acidic clouds and fog, which are often more acidic than the rainfall. When leaves are frequently bated in this acid fog their protective waxy coating can wear away. The loss of the coating damages the leaves and, and they become unable to produce enough food energy to remai
BIBILOGRAPHY
Books
Acid Rain, ? 1989, Wayland Publishers Ltd., East Sussex, England.
Kay, Kathleen – Acid Rain, ? 1983, Franklin Watts, New York. Howard, Ross and Perley
Poisoned Skies, ? 1991, Stoddart Publishing Co. Ltd., Toronto. Kahan
Web Sites
www.ns.ec.gc.ca/aeb/ssd/acid/acidfaq.html
www.ns.doe.ca/aeb/ssd/acid/poster1.html
www.ns.doe.ca/aeb/ssd/acid/index.html
www.econet.apc.org/acidrain/
www.gov.nb.ca/environm/operatin/air/acidrain.htm