What is Acid Rain and Smog?

Rain will be acidic or burning (at-Tabarani, al-Hakim)

What is Acid Rain?

Carbon dioxide in the air dissolves in atmospheric water to form carbonic acid. Carbonic is a weak acid, meaning it only partially ionizes to release H+(aq) ions, which results in a decrease in pH measure. For better clarification, acid precipitation is denoted as precipitation having a pH of 5.0 or lower.

Acid rain is “…caused by the reaction of water with deposits of nitrogen and sulphur oxides which result from fossil fuel combustion” (Kirkwood 7). Automobile exhaust produces nitrogen oxide, and sulphur oxides are produced “…mainly by electricity-generating plants, smelters, and industrial boilers that burn coal and oil” (Ramphal 36). These nitrogen and sulfur oxides enter the atmosphere and combine with other chemicals to give powerful reactions and form acid rain. Sulfur oxide enters the atmosphere and naturally mixes with water. The sulfurous acid reacts with water to yield partially ionized H+ (aq) because it is a weak acid. Other reactions besides sulfurous acid reacting with water can occur. Sulfur dioxide can react with oxygen or ozone to form sulfur trioxide. This chemical reacts with water molecules to form sulfuric acid. Sulfuric acid completely ionizes into its constituent ions. As additional H+ (aq) ions are released, the rain water becomes more acidic (Sources of Acid Rain 1).

Why is Acid Rain a Problem?

Through various forms of precipitation including rain, snow, mist and dew, acids formed by various chemical reactions in the atmosphere return to the earth and are deposited throughout nature and all over the globe. This relatively new phenomena gained more attention less than half a century ago when scientists in Sweden and Norway first attributed great ecological damage of the planet to it. At the beginning of the 1900s, most rivers and lakes in Norway were relatively “normal.” By 1926, signs of death were beginning to show: countless dead fish were found along the banks of many rivers, as well as at the bottom. When live fish from the rivers were examined, very small amounts of sodium were found in their blood, a symptom of acid poisoning. When the acid enters the fish’s gills, it prevents the fish from being able to extract salt from the water to maintain needed sodium levels (Anonymous2).

Until recently, the major loss of fish was contained to southern Europe. But as air pollution continues, lakes all over the world have turned dangerously acidic. As bodies of water become more acidic, the biodiversity of the water changes. The eggs of fish are killed when the pH level drops to 5.0. At this pH level, aquatic plants, insects and invertebrates on which fish depend on for food die out as well. At pH levels below 5.0, adult fish will die. Fish born in acid lakes do not survive because they usually have birth defects, such as twisted or deformed spinal columns, because they are not able to extract enough calcium from the water to completely develop (Anonymous3). Scientists have also found that “acidity also alters the body chemistry, destroys gills and prevents oxygen uptake, causes bone decalcification and disrupts muscle contraction” (Cunningham 408). The lake pollution exists not only in Europe, but around the globe, including in North America. Acid rain is also capable of extracting toxic metals out of rocks and soil, such as aluminum and mercury. Aluminum is an irritant for the fish, and the fish builds up mucus at the gills to stop the irritation. When the aluminum does not go away, the mucus inhibits the fish from breathing and they die.

Spreading across other forms of nature, acid rain's destructive force is inflicted upon soil and forests. The “…soils are experiencing elevated accumulations of nitrogen and sulfur. When deposition is reduced, sulfur bleeds out of the soil. With the uptake of sulfur and nitrogen, soils exhibit a significant loss of nutrient cations, principally calcium and magnesium” (Acid Rain 18). As acid deposition forces the soil to become more acidic, the aluminum that is toxic to many life forms is also released. Low pH levels in the soil assist the acceleration of soil weathering and eradicate nutrients and crucial cations such as calcium, sodium and potassium. Acid rain destroys the trees’ leaves, thus limiting their photosynthesis-derived nutrients and energy, causing them to be more vulnerable to disease, insects, and cold weather. Acid rain also impedes the growth of other plants and of mosses, algae, nitrogen-fixing bacteria and fungi that are essential for forest growth.

Acid rain not only destroys nature, but synthetic materials. Most structures are built out of marble and limestone due to the materials' durability. Both marble and limestone contain calcium carbonate (CaCO3); the difference between the two substances occurs at a crystalline structure level (Casiday 1). The calcium carbonate reacts with acid rain chemicals like sulfuric acid, resulting in corrosion. Repairing the damage of acid rain is very expensive. The following reaction describes how sulfuric acid is reacting with to destroy manmade structures.

CaCO3(s) + H2SO4(aq) à Ca2+(aq) + SO42-(aq)+ H2O(l) + CO2(g) (Casiday 1).

Aside from the various wildlife and objects that are destroyed by acid rain, human lives are also at stake. Acid rain releases poisonous metals that can be absorbed by drinking water, crops, or other food sources that humans consume. Consumption of those contaminated materials can cause nerve damage in children or severe brain damage or death. Other side effects are respiratory problems such as dry coughs, asthma, headaches, eye, nose, and throat irritation, and lung damage. “Because they are strong oxidizing agents, sulfates, SO2, NOx, and O3 act as irritants that damage delicate tissues in the eyes and respiratory passages” (Cunningham 406). When these materials get deep into the lungs of creatures, it causes heart problems because the heart begins to beat faster and harder to make up for the loss of oxygen experienced in the body. Acid rain is responsible for 550 premature deaths and 1,520 emergency room visits in the U.S. and Canada per year (All About Acid Rain 3).

Experts believe that the emissions from power plants reduces visibility by as much as 80 percent. An enormous type of cloud spans 2,000 miles across the eastern part of the U.S. during the summer, tainting the air’s clarity (Cunningham 410). For change to occur, it is important to be aware of the existing problem, how it originates, and measures that can be taken to reduce its impact.

How Can This Problem Be Remediated?

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What is Smog?

Smog in the Northern Adriatic Sea

Smog will appear over cities because of the evil that they are doing.

The term "smog" was first used in London during the early 1900's to describe the combination of smoke and fog. What we typically call "smog" today is a mixture of pollutants but is primarily made up of ground-level ozone.

Ozone can be beneficial or harmful depending on its location. The ozone located high above the Earth in the stratosphere protects human health and the environment, but ground-level ozone is responsible for the choking, coughing, and stinging eyes associated with smog.

Where Does Smog Come From?

Smog usually is produced through a complex set of photochemical reactions involving volatile organic compounds (VOC's) and nitrogen oxides in the presence of sunlight that result in the production of ozone. Smog-forming pollutants come from many sources, such as automobile exhausts, power plants, factories, and many consumer products, including paints, hair spray, charcoal starter fluid, solvents, and even plastic popcorn packaging. In typical urban areas, at least half of the smog precursors come from cars, buses, trucks, and boats.

Major smog occurrences often are linked to heavy motor vehicle traffic, high temperatures, sunshine, and calm winds. Weather and geography affect the location and severity of smog. Because temperature regulates the length of time it takes for smog to form, smog can form faster and be more severe on a hot and sunny day. When temperature inversions occur (warm air stays near the ground instead of rising) and winds are calm, smog may stay trapped over your city for days. As traffic and other sources add more pollutants to the air, the smog gets worse. Smog is often more severe away from the pollution sources because the chemical reactions that cause smog occur in the atmosphere while the reacting chemicals are being moved by the wind.

Severe smog and ground-level ozone problems exist in many major cities, including much of California from San Francisco to San Diego, the mid-Atlantic seaboard from Washington, DC, to southern Maine, and over major cities of the South and Midwest. To varying degrees, the majority of U.S. cities with greater than 250,000 population have experienced problems with ground level ozone.

What Are Its Effects?

Smog is made up of a combination of air pollutants that can injure health, harm the environment, and cause property damage. It has been estimated that about 90 million Americans live in areas with ozone levels above the established standards for health safety. These individuals can be severely influenced by pollutants on a daily basis.

Smog causes health problems such as difficulty in breathing, asthma, reduced resistance to lung infections and colds, and eye irritation. The ozone in smog also inhibits plants growth and can cause widespread damage to crops and forest, and the haze reduces visibility. The smog or haze, is particularly noticeable from mountains and other beautiful vistas, such those in National Parks.

How Do We Recognize/Detect It?

Smog is a visible example of air pollution. You can look at the horizon during the day to see how much haze there is in the air. In addition, most cities measure the concentrations of pollutants in the air and report the results to the public. Standardized measures have been established, like the Pollution Standards Index (PSI) (also called the Air Quality Index), which allow comparison of pollution levels from city to city.

How Do We Reduce Its Effects?

The 1990 Clean Air Act established a comprehensive approach to reducing the widespread "criteria" pollutants, which include the ozone, nitrogen oxides, and particulates in smog. EPA sets national standards for criteria pollutants, and the states must take action to ensure that the standards are met. Areas that fail to meet the standards for at least one criteria air pollutant are called "nonattainment areas."

Areas of nonattainment for criteria pollutants have been classified according to the extent of pollution. The five classes for ozone nonattainment range from marginal (relatively easy to clean up quickly) to extreme (will take a lot of work and a long time to clean up). The 1990 Clean Air Act uses these classes to tailor cleanup requirements to the severity of the pollution and to set realistic guidelines for reaching cleanup goals. Many of the smog cleanup requirements involve motor vehicles (cars, trucks, buses). Also, as the pollution gets worse, pollution controls are required for smaller sources.

Strategies that may be required by law to reduce and control air emissions include state permitting programs, changes in the composition of gasoline, use of alternative fuels (such as natural gas and electricity), and use restrictions imposed by individual communities. Innovative approaches are being taken by local governments across the country to reduce air pollution in nonattainment areas. These include: banning charcoal barbecues and wood burning in stoves or fireplaces when pollution levels are high; developing programs to encourage carpooling and voluntary "ozone actions"; restricting traffic in congested areas; expanding or improving public transportation systems; requiring employers to contribute to employee mass transit costs; assessing "smog fees" on cars in proportion to the number of miles driven and vehicle emissions produced; and even buying and scrapping older, "super-dirty" cars.

More Information on Smog

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