Acid RainMy first question is , “What is Acid Rain?” You hear about it all the timein the news and it is very important to the earth’s ecosystem.
In simpleterms, acid rain is rain that is more acidic than normal. All objects in naturehave a certain level of acicicity but acid rain has too much acid in it. Acidrain is a complicated problem, caused by air pollution. Acid rain’s spread anddamage involves weather, chemistry, soil, and the life cycles of plants andanimals on the land and from acid rain in the water. Acidity is measured using apH scale, with the number 7 being neutral.
Therefore, a body with a pH value ofless than 7 is acidic. On the other hand, a value greater than 7 is basic. ThepH of 5. 6 has been used as the baseline in identifying acid rain, although thisvalue is controversial, therefore, acid ran is any rainfall that has an aciditylevel above what is expected in non-polluted rainfall. Any precipitation thathas a pH value of less than 5.
6 is considered to be acid precipitation. Readingsof pH 2. 4–as acidic as vinegar–were recorded during storms in New England. During one particularly acid summer storm, rain falling on a lime-greenautomobile leached away the yellow in the green paint, leaving blue raindropshaped spots on the car.
Scientists have found that pollution in the air fromthe burning of fossil fuels is the main cause of acid rain. The major chemicalsin air that help to create acid rain are sulfur dioxide, known as (SO2), andnitrogen oxides, known as (NOx). Acid rain is formed high in the clouds wheresulfur dioxide and nitrogen oxides react with water, oxygen, and oxidants. Thislethal mixture creates a mild solution of sulfuric acid and nitric acid. Sunlight often increases the speed at which the reaction occur.
Rainwater, snow,fog, and other forms of precipitation containing these new solutions of sulfuricand nitric acids fall to earth as acid rain. Acid rain does not make up all ofthe acidity that falls back to earth from pollutants. Only half of the acidityin the air falls back to earth through dry deposition as gases and dryparticles. The wind blows and then these acidic grains are blown onto buildings,cars, homes, and trees. In some cases, these particles can eat away the objectswhich they land on. Dry deposited gases are sometimes washed from trees andother surfaces by rainstorms.
When this occurs, the runoff water adds the newacids to the acid rain, making a more acidic combination than the falling rainby itself. One of the main causes of acid rain is the sulfur dioxide. Sulfurdioxide is one of the main ingredients which make up the deadly combination thatforms acid rain. Some of the natural sources that emit this gas are rottingvegetation, volcanoes, plankton, rotting animals and sea spray. However, theburning of fossil fuels, such as coal and oil, do not help the situation and arelargely to blame for approximately half of the emissions of this gas in theworld.
Water moves through living plants, animal, streams, lakes, and oceans inthe hydrologic cycle. In that cycle, water evaporates from the land and sea intothe atmosphere. Water in the atmosphere then condenses to form clouds. Cloudsrelease the water back to the earth as rain, snow, or fog. When water dropletsform and fall to the earth, they pick up particles and chemicals that float inthe air.
Even clean, unpolluted air has some particles such as dust or pollen. Clean air also contains naturally occurring gases such as carbon dioxide. Theinteraction between the water droplets and the carbon dioxide in the atmospheregives rain a pH of 5. 6, making even clean rain slightly acidic. Other naturalsources of acids and bases in the atmosphere may lower or raise the pH ofunpolluted rain.
However, when rain contains pollutants, especially sulfurdioxide and nitrogen oxides, the rain water can become very acidic. This problemis a problem of natures balance being tampered with. If not polluted, normalprecipitation would react with chemicals that are derived from bedrock in theair, soil, lakes, and streams and this rain would be neutralized. Since theprecipitation is highly acidic, these natural buffering chemicals will bedestroyed. When this occurs, the natural buffering effect does not occur, andnature won’t keep it’s balance Acid rain has been a big problem for a longtime.
Research on acid rain is just starting to make progress. In the past,little was known about the causes and effects of acid rain. Lakes, rivers,oceans, and other aquatic ecosystems are largely affected by acid rain. Thereason why acid rain has such a large affect on aquatic ecosystems is becausethere as so many routes in which acidic chemicals can enter the water.
Chemicalsubstances enter the water in different ways. Some of the ways acidic chemicalsenter waterways are as dry particles. These chemicals can also get into thewater in forms such as rain, hail, dew, fog and snow. Another way that acidsenter the lakes is called spring acid shock. An example of spring acid shock iswhen snow melts in the spring rapidly as a result of a sudden temperaturechange. The acids in the snow are then put into the soil.
The melted snow inreturn runs off to smaller water sources, and gradually make their way into thelarger water ecosystems. This causes a sudden drastic change in the pH level. The aquatic ecosystem doesn’t have time to adjust to the drastic change. Thisis also very dangerous because in the springtime many aquatic species arereproducing. Some of these species lay their eggs in the water to hatch.
Thesudden pH change can cause serious deformities in their young or even kill offthe whole species since the young spend a lot of their crucial primary lifecycle in the water. Sulfuric acid in water can affect the fish in the water intwo ways: directly and indirectly. Sulfuric acid directly interferes with thefish’s ability to take in salt, oxygen and nutrients crucial for daily life. Osmoregulation is the process of maintaining the delicate balance of salts andminerals in their tissues. For freshwater fish, maintaining osmoregulation iskey in their survival. Acid molecules, which are a result of acid rain in thewater, cause mucus to form in the fish’s gills.
This in return prevents thefish from absorbing oxygen. If the fish are unable to absorb oxygen, theconsequence could be the eventual suffocation of fish and the low pH could throwoff the balance of salts in the fish tissue. Salt levels such, as the calcium(Ca+2), levels of some fish cannot be maintained due to pH change. This canresults in poor reproduction. The fish’s eggs produced would be damaged, theycould either be too brittle or too weak. The decreased Ca+2 levels also resultin weak spines and deformities.
Acid Rain is very tragic when it come to thelife of fish, but when nitrogen-containing fertilizers are washed off into thelakes, the nitrogen stimulates the growth of algae, which logically would meanan increase in oxygen production, thus benefiting the fish. This can bebeneficial, but because of increased deaths in the fish population due to acidrain, the decomposition process uses up a lot of the oxygen, which leaves lessfor the surviving fish to take in. Indirectly, sulfuric acid releases heavymetals present in soils to be dissociated and released. For example, aluminum(Al+2) is harmless as part of a compound, but because acid rain causes Al+2 tobe released into the soils and gradually into the lakes, it becomes lethal tothe health of the fish in the lakes on its life forms. Some of the pH leveleffects are ; At pH level six basic forms of food die off for fish. The foodsources cannot survive at this pH level.
At a pH level of 5. 5 there are moredeformed adult fish due to lack of nutrients. The fish cannot reproduce. Theyoung have difficulty staying alive, and eventually the older fish will die ofsuffocation. At pH level 5.
0 the whole fish population will die off. At pH level4. 0 all life forms will die. Fish, being one of the most important members ofthe food chain, provide nourishment for other creators. Since acid rain isaffecting fish, this makes it dangerous for other creators including humans toeat the fish. Other sea dwellers such as amphibians are also affected by acidran.
The amphibian embryos have membranes that are too tough because of theacids, such that they are unable to break through at the proper time. So, theycontinue to grow, only to have deformed spines. The affects on water forms arethe greatest and most tragic of all of the things that acid rain affects. Acidrain affects all that eat seafood or any other water dwelling life form.
Anotherthings impacted by acid rain are forests and soil. When acid rain falls onto theearth’s surface it causes a lot of damage. The soil is robbed of some vitalthings. Aluminum that is always present in the soil is freed, and the toxicelement is absorbed by the roots of trees. The trees in turn are starved anddeprived of vital nutrients such as calcium and magnesium. Sulfuric acid returnsto earth.
When the sulfuric acid returns, it clogs up the stomata in the leaves,stopping photosynthesis. In addition, severe frosts may also further aggravatethis situation. With sulfur dioxide, ammonia and ozone present in the air, thefrost-hardiness of trees are reduced. Ammonia mixes with sulfur dioxide andforms ammonium sulfate.
This product forms on the surface of the trees. Whenammonium sulfate reaches the soils, it reacts to form both sulfuric and nitricacid. Such conditions also stimulate the growth of fungi and pests like theambrosia beetle. When trees are under such stress, they release chemicals suchas terpenes which attract the ambrosia beetle. Acid rain also affects theatmosphere. The affects on the atmosphere are mostly due to dry deposition thatwas mentioned earlier.
The floating particles can contribute to haze, whichaffects visibility. This makes navigation especially hard for air pilots. Theacid haze also inhibits the flow of sunlight from the sun to the earth and back. Acid rain also affects architecture. Architecture is affected by both dryprecipitation and wet precipitation.
When these particles land on building theyeat into the concrete eventually destroying them. This is a potential dangerbecause the infrastructure of the buildings can be destroyed, thus hurtingpeople occupying the building Acid Rain also has a direct affect on you and I. The SO2 and NO2 emissions give rise to respiratory problems such as asthma, drycoughs, headaches, eye, nose and throat irritations. The indirect affect of acidrain are on the food that we eat. Acid rain is absorbed in fruits, and in thetissues of animals.
Although these toxic metals do not directly affect theanimals, they have serious affects on humans when they are being consumed. Acidrain is a huge problem which affects every person living in the world in somesort of way. Acid rain is a problem that can be reduced but not stoppedcompletely due to the needs of our modern society. Some ways that we could helpto reduce acid rain is by recycling, carpooling, and reducing. Acid rain is aproblem that can be controlled but it is up to the people of earth to controlthe problem. Bibliography1.
Heij, G. J. and J. W.
Erisman (Editors). Acid Rain Research: Do we haveenough answers? New York: Elsevier, 1995. 2. Comptons New Media Encyclopedia 19963.
White, James C. (Editor). Acid Rain: The Relationship between Sources andReceptors. New York: Elsevier, 1988.
4.FAQ on Acid Rain(http://ns.doe.ca/aeb/ssd/acid/acidFAQ.html)
