Acid Rain is Destroying Our World

Acid rain causes increasing, almost irreversible damage to the global environment every year and no country is immune to its effects. Bodies of water, plant life, animals, building structures, and historical monuments on the east coast of the United States and Canada, as well as European countries such as Germany, Norway, and Great Britain are among some of those affected by acidic rainfall. To understand the issues surrounding acid rain one must first understand how acid rain is formed, what it is formed from, as well as the problems it causes to our ecological environment. This paper will discuss these issues as well as some possible solutions to this wide spread problem.

One of the most important things to understand when discussing acid rain is how to interpret what is considered acidic and what is not. Acidity in liquids is determined by their pH levels and is measured on a pH scale ranging from zero to fourteen. Liquids containing a pH level that is less than seven are considered acidic, likewise, liquids with a pH level that is higher than seven are considered basic (also known as alkaline). According to Alters and Alters (2007) healthy environmental precipitation occurs at "slightly acidic" levels, approximately 5.7 pH. Acid rain is considered to fall between the pH levels of 3.5 and 5.5, although more drastic levels of acidic rain have been measured in certain parts of the United States (748). In other words, acid rain is usually somewhere around the same acid content as coffee or orange juice.

Acid rain is causes by various pollutants put into the air by human activity, such as emissions from diesel trucks, sports utility vehicles, busses, and other automobiles, as well as the burning of a number of fuels. The effects of these kinds of air pollution can be seen in large crowded cities such as New York, Los Angeles, Chicago and Shanghai, China, where the smog levels and unhealthy air quality are almost notorious and widely visible during the afternoon and evening hours. Acid rain is formed when the chemicals in the air pollutants, specifically sulfur dioxide (SO2) and nitrogen oxides (NO) combine with water molecules and becomes acidic. The combination of these two pollutants and water (H2O) then precipitate to the ground in what is known as "acid rain." According to the Bureau of Air Quality in Maine (2005), acid rain, also known as acid precipitation or acid deposition, can fall to the ground in many different forms other that just pure rain, such as "snow, sleet, hail, or fog; acid deposition may also occur as dry particles or dust settling out of the atmosphere." Since acidic fall out can happen in such varied forms the damage that it can cause to a variety of environments can be disastrous.

Acid rain is most prevalent in areas with a high volume of industrialization and ground traffic by nitrogen oxide (NO) emitting automobiles. Cities that are closer in proximity to one another must deal with the pollution not only within their cities parameters but also with the inward drift of pollution from surrounding cities as well. This makes a higher concentration of sulfur dioxide (SO2) and nitrogen oxide (NO2) molecules in the air to combine with the water (H2O) molecules to form acid rain. Alters and Alters (2007) cite a very specific example of pollutant drift into an already polluted area stating, "The eastern United States receives some of the emissions created in the Midwest as winds carry them eastward, while the wind takes emissions created in the north east into Canada" (748). Drift pollution and the acid rain that follows also affects numerous cities in and around central Europe and Asia, who also suffer from the devastating effects of acid rain.

The effects of acid rain on the natural environment have been well documented around the world. Acid rain affects various ecosystems in devastating ways; it poisons bodies of water by making its contents acidic, essentially changing the molecular structure of water and making it difficult for aquatic life to survive. It also damages the soil of affected areas causing high levels of metal to surface in the soil. Increased metal levels in the soil damages the roots of vegetation and poisons the ground water used for hydration in plants and animals, such as humans and trees. The fall of acid rain on vegetation also causes the leaves of the plants to be damaged and loose their healthy green color. The lack of pigmentation in the leaves blocks the plants or trees ability to process sunlight and thus stops photosynthesis. When a tree or plant is exposed to regular amounts of acid rain the damage continues to increase and eventually kills the organism.

Another example of the effects of acid rain are highlighted by the BBC News (2002) who cites a large decline in a particular species of bird known as the wood thrush, which is native to North America. They further explain the reason for this decline stating, "Pollution in the form of acid rain causes a number of effects on trees- from the loss of pine needles and leaves, to their complete destruction. The implication for birds include fewer insects to eat, more danger from predators and changes to nesting and roosting habits" (BBC News, 2002). The implications of the destruction of a food chain and habitat loss in a region in North American affect the entire food web and habitat of a larger ecosystem of organisms. Other documented loss in vegetation and damage to lakes, ponds, rivers, and fish due to acid deposition and precipitation include areas of Canada and New England (McGee, 1997), though the effects of acid rain can be traced through out the globe.

Acid rain not only damages the natural environment, it also devastates building structures and monuments susceptible to the unnaturally acidic water. Limestone Granite, and Marble were three very popular building materials used before the 1900's. Among those three building materials two of them, Limestone and Marble, "dissolve readily in weak acid" (McGee, 1997), such as an acidic precipitation. Monuments in European countries as well as early buildings in colonial America, such as Philadelphia and Boston are dealing with structural problems (from dissolving Marble and Limestone) due to acid rain damage. Historical monuments are at risk of being destroyed if acid rain cannot be neutralized in a timely and effective manner.

Rapid reduction of air pollutants in our environment is necessary to reduce or eliminate the effects of acid rain before it is too late. According to the Bureau of Air Quality (2005) in Maine, "Studies suggest that it is possible for ecosystems damaged by acid deposition (precipitation) to recover. The rate at which recovery occurs and the extent to which the recovery happens is dependent upon the magnitude of the reductions in sulfur dioxide (SO2) and nitrogen oxide (NO) emissions." Solutions to acid rain are essentially the same as those used to solve the overwhelming problem of air pollution within our cities. Industrial and power plants need to reduce their use of fossil fuels, such as coal and oil, and change to more environmentally friendly energy sources such as wind, water, wave, solar, or biothermal power. Exhaust from cars, sports utility vehicles and diesel trucks contribute a big part of the air pollution people breathe a day, thus adding chemicals to the air and aiding in the production of acid rain. To help fix this problem, large cities should to focus their efforts on producing effective mass transit to aid in the decongestion of highways and the over usage of automobiles to get around. Alters and Alters (2007) also suggest the usage of "coal-fired power plant scrubbers (if coal power plants are used), energy conservation, and the recycling of resources" (748). All of these combined efforts can effectively reduce pollutants in the air and curb the acidity in rain. This would allow each affected ecosystem to return to its natural state and regain a healthy balance within our environment for all the organisms residing in it.

References

Alters, S., Alters B. (2007). Biology: Understanding Life. Hoboken: Wiley & Sons, Inc.

-From this book I learned about the pH levels of natural rain and pollutant drift and how it affects the production of acid rain. In addition, this book gave a few good solutions to deal with the problem of acid rain in the environment.

BBC News. (2002). "Forests Fall Silent with Acid Rain." BBC News World Report. Retrieved Aug. 2, 2007, from http://www.news.bbc.co.uk/2/hi/science/nature/2189151.stm

-This website provided a specific example of the devastating effects of acid rain on a population of wood thrush birds. It taught me how problems within a small food chain can grow and spread to problems with an entire food web.

Bureau of Air Quality. (2005). "Acid Rain." Department of Environmental Protection: State of Maine. Retrieved Aug. 2, 2007, from http://www.maine.gov/dep/air/acidrain/

-This website provided me with information about what acid rain actually is and how it falls to the ground in many different ways. This website also gave some positive insight on the possibility of the environment healing if acid rain can effectively be dealt with.

McGee, Elaine. (1997). "What is Acid Rain." USGS. Retrieved Aug 2, 2007, from http://www.pubs.usgs.gov/gip/acidrain/index.html-This website provided me with valuable information about the ecosystems in which acid rain affects heavily (in North America). It also gave a vast amount of information concerning building materials and their susceptibility to acid rain.