Acid Rain
... particles will combine with other compounds to produce new, often harmful chemicals. Nitrogen oxide can spread far from the location where it originated because of acid rain. Acid rain is having harmful effects on both people and the natural ecosystems of the world. Scientists today are convinced that acid rain is severe in many areas, and that it is having an adverse effect on the environments of those locations. The problem of acid rain is rapidly spreading. Due to this problem being mainly caused by industrial processes, automobiles, and power plants, those countries that are considered “developed” have the most severe acid rain problems. However, as the undeveloped nations begin to individualize, the percentage of acid rain will increase greatly. Over a span of several years, scientists have noticed that some forests have been growing at a gradually slower rate without discernable cause. Trees no longer grow as fast as they did before and their leaves and pine needles now turn brown and fall off when they are supposed to be green. The forests of the Federal Republic of Germany, as well as other places in Western Europe, for example, are believed to be dying because of acid rain (Acid Rain, p.2). After conducting studies, collecting and recording information on the chemistry and biology of the forest, researchers have come to the conclusion that this was the work of acid rain. Toxic metals such as lead, zinc, copper, chromium, and aluminum are deposited in the forest from the atmosphere. The acid rain releases these metals and they stunt the growth of trees and other plants, as well as the growth of mosses, algae, fungi, and nitrogen-fixing bacteria needed for forest growth. The process is thought to begin with a forest rainstorm where the water that is not retained by the trees is absorbed into the soil. This soil, more than likely, may have neutralized some or all, of the acidity of the acid rainwater. The ability of neutralization is called buffering capacity, and, without it, the pH of the soil would change rapidly. High pH levels in the soil help accelerate soil weathering and removes nutrients. It also makes toxic elements, such as aluminum, more soluble. High aluminum concentrations in soil can prevent the use of nutrients by plants. Acid rain does not kill trees immediately or directly. Instead, it is more likely to weaken the tree by destroying its leaves, thus limiting the nutrients available to it. Another possible method of tree destruction is by acid rain seeping into the ground, poisoning the trees with toxic substances that are slowly being absorbed through the roots. When the acid rain falls, the acidic rainwater dissolves most of the nutrients and helpful minerals from the soil. These minerals are then washed away before the trees and other plants can use them to grow. When acid rain is frequent, leaves tend to lose their protective waxy coating and the plant becomes susceptible to any possible disease and interrupts the evaporation of water and gas exchange so that the plant can no longer breathe. By damaging the leaves, the plant cannot produce enough food energy for it to remain healthy. After becoming weak, a plant is vulnerable to disease, insects, and cold weather, which may ultimately destroy the plant. Perhaps the most important effects of acid rain on forests result from nutrient leaching, accumulation of toxic metals and the release of toxic aluminum. Nutrient leaching occurs when acid rain adds hydrogen ions to the soil that interact chemically with existing minerals. This displaces calcium, magnesium, and potassium from soil particles and deprives trees of nutrition. This processing damages the plants’ ability to survive and give life to other organisms. Acid rain does not only effect organisms on land, but it also impacts organisms in aquatic biomes. Most lakes and streams have a pH level between six and eight. Some lakes are naturally acidic without the effects of acid rain. There are several ways through which acid rain generally enters most lakes. Some chemical substances exist as dry particles in the atmosphere, while others enter directly into the lake through some form of precipitation. Acid rain that has fallen on land can be drained through sewage systems leading to lakes. Another way most acids come into the lake is by spring acid shock. This occurs in the spring when the snow melts and the acids from the snow seep into the ground. Some of this acid spreads from the ground and into the lakes. Acid rain effects lakes, rivers, ponds, streams, bays and other bodies of water by increasing their acidity until fish and other aquatic creatures can no longer live. Spring is a vulnerable time for most aquatic species because it is the time when most reproduce. The abrupt shift in pH levels is hazardous because of its ability to cause deformities in their young. Furthermore, not all species can tolerate the same amount of acid. At pH 6, freshwater shrimp cannot survive and at pH 5.5, bottom-dwelling bacterial decomposers begin to die and leave undecomposed leaf litter and other organic debris to collect on the bottom. This deprives plankton, known as the tiny creatures that form on the base of the food chain, of food, so that they also cease to exist. Below a pH of about 4.5, all fish die (Contaminant Hydrogeology, p.107) . Most importantly, acid rain is affecting the health and wellness of human beings. It can harm us through the soil from which our food is grown and eaten from or through our atmosphere. Dangerous toxic metals are being absorbed in humans by the drinking water, crops, and the animals they consume. These foods that are being consumed could cause nerve damage to children, severe brain damage, or even death. Scientists suspect that consumption of one metal in particular, aluminum, is directly related to Alzheimer’s disease (Atmospheric Pollutants, p.96). Respiratory problems are also a serious side effect of acid rain on humans. The sulfur dioxide and nitrogen oxide emission gives risk to respiratory problems such as dry coughs, asthma, headaches, eye, nose, and throat irritation. Polluted rainfall is especially harmful to people who have a hard time breathing or those who suffer from asthma. However, even seemingly healthy people can be at risk for lung damage by acid air pollutants. Modern science has proven that acid rain is a dangerous and highly destructive problem. As a result, various solutions to the acid rain problem have been devised. In 1991, the United States and Canada signed an air quality agreement in which both countries agreed to reduce their annual sulfur emission and, over a ten-year time period, reduce sulfur oxide emission by about 10 million tons (Global Challenge, p. 4). A year before the agreement, the Clean Air Pact Amendment tried to reduce nitrogen oxide by two million tons. This program focuses on the source that emits nitrogen oxide, automobiles, and coal-fired electric utility boilers. In order to reduce sulfur dioxide emission, utility plants are required to complete several steps. Before combustion, these utility plants have to go through a process called coal cleaning. This particular process is performed gravitationally, meaning that it is successful in removing pyritic sulfur due to its high specific gravity. However, it is ineffectual in removing chemica...