Introduction
Pollution entails the introduction of substances into the environment in quantities that can change environmental conditions and in turn, harm organisms. Acid rain and ozone pollution are a form of pollution, which entails the release of gaseous and dust particles in quantities that destroy the integrity of the atmosphere and affect organisms in their respective habitats and ecosystems.
Essentially, the atmosphere is an integral natural resource of the earth because it contains and maintains gases in appropriate proportions, which are essential for the survival of organisms in nature. In this case, the occurrence of acid rain and ozone pollution is due to the emission of gases in huge quantities, which have the capacity to pollute the air. Singh and Agrawal state that human activities such as the burning of fossil fuels and natural causes such as volcanic eruptions release nitrogen oxides, sulfur dioxides, and ozone, which are precursors of acid rain (15).
These oxides combine with atmospheric water and form acid rain. Aggarwal et al. state that the interaction of nitrogen oxides and volatile organic compounds contributes to the formation of terrestrial ozone, which is a pollutant responsible for global warming (1991). In this view, to enhance understanding of air pollution, the research paper examines the nature of acid rain and ozone pollution and subsequently discusses its causes and effects.
The Nature of Acid Rain and Ozone Pollution
Acid rain is a form of pollution characterized by the presence of nitric acid and sulfuric acid in the rain, snow, hailstones, dew, and fog. The presence of nitrogen oxides (NOx) and sulfur dioxide (SO2) in the atmosphere leads to the formation of acid rain. According to National Atmospheric Deposition Program, carbon dioxide, oxygen, sunlight, ozone, and water catalyze the conversion of nitrogen oxides and sulfur dioxide into nitric acid and sulfuric acid, respectively (par. 2).
These acids then accumulate in the atmosphere and fall to the earth’s surface as rain, snow, dew, fog, and hailstones. The amount of nitric acid and sulfuric acid is proportional to the number of nitrogen oxides and sulfur dioxide that are present in the atmosphere (Singh and Agrawal 15). Hence, acid rain occurs when there are high proportions of nitrogen oxides and sulfur dioxide in the atmosphere.
Ozone pollution is a form of air pollution, which occurs when the amount of ozone (O3) increases in the atmosphere. Although ozone that is present in the stratospheric layer is important because it protects humans and organisms against harmful ultra-violet radiation, its presence in the tropospheric layer is harmful. Aggarwal et al. argue that the presence of ozone in the tropospheric layer constitutes pollution because it acts as particulate matter that scatters sunlight, promotes absorption of ultra-violet radiation, and causes global warming (1990). Hence, terrestrial ozone is a very harmful pollutant to humanity and organisms.
Causes of Acid Rain and Ozone Pollution
Human activities and natural processes are the cause of acid rain. The human activities that emit nitrogen oxides and sulfur dioxide are exhaust fumes from motor vehicles, industrial emissions from smelters and fossil fuels, and power stations that use fossil fuels (Singh and Agrawal 15). Given that exhaust fumes from motor vehicles and industrial emissions are common in urban centers, the emissions of nitrogen oxides and sulfur dioxides are very high.
National Atmospheric Deposition Program states that urban centers with high population density, automobile traffic, and industrial activities experience high levels of nitrogen oxides and sulfur dioxide emissions (par. 9). Natural sources of nitrogen oxides and sulfur dioxide are lightenings, oceans, and volcanic eruptions (Singh and Agrawal 15). However, these natural sources do not contribute significantly to acid rain.
An increased amount of terrestrial ozone occurs due to human activities, which release nitrogen oxides and hydrocarbons into the atmosphere. According to Aggarwal et al., motor vehicles, industries, and power plants burn fossil fuels and emit nitrogen oxides and hydrocarbons, which interact in the presence of ultra-violet radiation and lead to the formation of ozone (1990). The number of ozone peaks late in the afternoon after the emitted gases have absorbed enough heat to catalyze the formation of ozone.
Effects of Acid Rain and Ozone Pollution
Acid rain and ozone pollution have harmful effects on organisms because they have scorching effects on the leaves of plants. Given that acids have scorching effects, they destroy the integrity of the leaves and interfere with their functions. National Atmospheric Deposition Program states that acid damages leave and make them susceptible to environmental stresses and diseases (p. 12).
Singh and Agrawal also indicate that ozone damages leave by causing desiccation and changing coloration (1992). The damaged leaves lose their physiological functions of photosynthesis and cause plants to experience retardation in their growth and development. The ability to regulate the loss of water is lost; hence, predisposing plants to physiological drought. Moreover, the scorching effects of acids destroy the protective membranes of plants and make them susceptible to diseases.
Since organisms in the environment live within a narrow range of pH, acid rain causes a significant drop in the normal pH. Singh and Agrawal explain that acid rain causes acidification of water bodies and results in massive deaths of aquatic organisms such as fishes, amphibians, planktons, and microorganisms (18).
A slight change in aquatic pH has deleterious effects on organisms because it affects their biochemical and physiological processes. A normal aquatic environment has a pH of 6.5 or more, but a few organisms can survive at a pH of 5; however, none can survive on a pH of less than 5 (National Atmospheric Deposition Program par. 15). Therefore, acid rain has the potential to kill all aquatic organisms if it occurs on a large scale.
Acid rain also has a considerable impact on agriculture because it affects the availability of nutrients in the soil. National Atmospheric Deposition Program reports that acid rain lowers agricultural production by reducing soil nutrients, changing the proportion of chemicals in the soil, and killing important microbes in the soil (par. 16). Acid rain reduces soil nutrients because it dissolves and leaches them away. Singh and Agrawal’s state explain that acid rain reduces the pH of the soil and causes the liberation of cations such as potassium, magnesium, and calcium, which are important in the growth and development of plants (18).
When leaching occurs, the proportion of nutrients in the soil reduces, while the proportion of toxic heavy metal increases. A decrease in pH harms microbes in the soil, hence, reducing the rate at which important microbial processes occur in the soil. Ozone is a greenhouse house gas, which has the capacity to cause global warming and affect the distribution of rainfall patterns in various places globally. Aggarwal et al. assert that the increased concentration of terrestrial ozone contributes to global warming because it has a greenhouse effect.
Acid rain has harmful effects on humanity because it dissolves heavy metals and causes respiratory diseases. National Atmospheric Deposition Program states that acid rain pollutes water by dissolving lead and copper, which are harmful metals, and inhalation of acidic fog causes respiratory illnesses such as asthma (par. 19). Exposure to lead and copper causes mental and systemic illnesses. The elderly are prone to respiratory diseases owing to their aging respiratory system.
Despite the fact that ozone in the stratosphere is protective against ultra-violet radiation from the sun, its presence in the troposphere is harmful to humanity and organisms. Ozone pollution has harmful effects on humanity because long-term exposure increases the occurrence of asthma, skin diseases, and lung cancer among individuals (“Green Facts: Air Pollution” par. 3). Aggarwal et al. argue that the combined effect of ozone and carbon monoxide causes acid rain and subsequently contributes to the damage of lung tissue (1990). In this view, acid rain and ozone pollution are responsible for the increasing cases of lung cancer and asthma.
Given that acid has corroding effects, acid rain corrodes human structures. National Atmospheric Deposition Program reports that buildings, statues, monuments, vehicles, metallic structures, and tombstones corrode faster in acid rain than in normal rain (par. 21). In this case, acid rain hastens deterioration of human structures, and thus, reduces their longevity.
Conclusion
Acid rain and ozone pollution are the dominant forms of air pollution because they emanate from human activities. Emissions of nitrogen oxides and sulfur dioxide do not only lead to the formation of acid rain but also act as catalysts in the formation of ozone.
The combined effect of acid rain and ozone leads to the destruction of terrestrial plants, death of aquatic organisms, reduced agricultural production, the emergence of human diseases such as lung cancer, asthma, and skin diseases, and deterioration of human structures. Therefore, acid rain and ozone pollution are public and environmental health issues that require effective mitigation measures.
Works Cited
Aggarwal, Anjali, Reeta Kumari, Neeti Mehla, Rishi Singh, Sonal Bhatnagar, Kameshwar Sharma, Kuldeep Sharma, Amit Vashishtha, and Brijesh Rathi. “Depletion of the ozone layer and its consequences: A review.” American Journal of Plant Sciences 4.10 (2013): 1990-1997. Print.
Singh, Anita, and Madhoolika Agrawal. “Acid rain and its ecological consequences.” Journal of Environmental Biology 29.1(2008): 15-24. Print.
National Atmospheric Deposition Program. Acid Rain. 2014. Web.
Green Facts: Air Pollution Ozone 2015. Web.