chapter 15Review
In this chapter, we examined the major air pollutants and their natural and anthropogenic sources. We found that photochemical smog and acidic deposition are two air pollution problems that have had different outcomes, at least for now. Smog is still a problem in many locations around the world while acidic deposition has become less of a problem in North America and Europe. There are a variety of measures for controlling air pollution including pollution prevention and devices that remove pollutants from smokestacks before it is released into the atmosphere. Stratospheric ozone depletion has occurred because of the release of chlorofluorocarbons (CFCs) from refrigeration and air-
Air pollution Particulate matter (PM) Particulates Particles Haze Photochemical oxidant Ozone (O3) Smog Photochemical smog Los Angeles–type smog Brown smog Sulfurous smog London-type smog Gray smog Industrial smog Volatile organic compound (VOC) Primary pollutant Secondary pollutant Thermal inversion Inversion layer Asbestos Sick building syndrome | A secondary pollutant made up of three oxygen atoms bound together. Solid or liquid particles suspended in air. Also known as Particulates; Particulate matter (PM). A situation in which a relatively warm layer of air at mid-altitude covers a layer of cold, dense air below. Smog dominated by sulfur dioxide and sulfate compounds. Also known as Sulfurous smog; Gray smog; Industrial smog. Solid or liquid particles suspended in air. Also known as Particulates; Particles. An organic compound that evaporates at typical atmospheric temperatures. Smog dominated by sulfur dioxide and sulfate compounds. Also known as London-type smog; Sulfurous smog; Industrial smog. Smog that is dominated by oxidants such as ozone. Also known as Los Angeles–type Smog; Photochemical smog. A long, thin, fibrous silicate mineral with insulating properties, which can cause cancer when inhaled. Smog that is dominated by oxidants such as ozone. Also known as Photochemical smog; Brown smog. Smog dominated by sulfur dioxide and sulfate compounds. Also known as London-type smog; Gray smog; Sulfurous smog. A primary pollutant that has undergone transformation in the presence of sunlight, water, oxygen, or other compounds. Smog dominated by sulfur dioxide and sulfate compounds. Also known as London-type smog; Gray smog; Industrial smog. Reduced visibility. Smog that is dominated by oxidants such as ozone. Also known as Los Angeles–type Smog; Brown smog. Solid or liquid particles suspended in air. Also known as Particulate matter (PM); Particles. A class of air pollutants formed as a result of sunlight acting on compounds such as nitrogen oxides. The introduction of chemicals, particulate matter, or microorganisms into the atmosphere at concentrations high enough to harm plants, animals, and materials such as buildings, or to alter ecosystems. A buildup of toxic pollutants in an airtight space, seen in newer buildings. A type of air pollution that is a mixture of oxidants and particulate matter. A polluting compound that comes directly out of a smokestack, exhaust pipe, or natural emission source. The layer of warm air that traps emissions in a thermal inversion. |
Module 46 Major Air Pollutants and Their Sources
Identify and describe the major air pollutants.
Sulfur oxides, nitrogen oxides, carbon monoxide, carbon dioxide, particulates, and ozone are some of the major ground-
Describe the sources of air pollution.
Air pollution comes from both natural and human sources. Human activities that release these pollutants or their precursors include transportation, generation of electricity, space heating, and industrial processes.
Module 47 Photochemical Smog and Acid Rain
Explain how photochemical smog forms and why it is still a problem in the United States.
Smog forms when sunlight, nitrogen oxides, and volatile organic compounds are present. The secondary pollutant ozone is a major component of photochemical smog. Sulfur is the dominant ingredient in sulfurous smog. Smog impairs respiratory function in human beings. Because of an abundance of both nitrogen oxides and volatile organic compounds, smog occurs during daylight hours in many parts of the world, including the United States.
Describe how acid deposition forms and why it has improved in the United States and become worse elsewhere.
Acidic deposition, which is composed of hydrogen, sulfate, and nitrate ions, forms from both sulfur dioxide and nitrogen oxides. Acid deposition is harmful to aquatic organisms and can reduce forest productivity in sensitive ecosystems. Due to reductions in sulfur emissions in the United States, acidic deposition is much less of a problem than it used to be. Asia is a location today where acidic deposition is an environmental problem.
Module 48 Pollution Control Measures
Explain strategies and techniques for controlling sulfur dioxide, nitrogen oxides, and particulate matter.
Air pollution is best controlled by increasing the efficiency of processes that cause pollution, thereby reducing emissions, or by removing pollutants from fuel before combustion. After combustion occurs, filters and scrubbers remove pollutants from the exhaust stream before they can be released into the environment. The use of filters and scrubbers is preferable to trying to remove pollutants after they have been distributed throughout the environment.
Describe innovative pollution control measures.
Some innovative approaches to pollution control include targeting specific sources of certain kinds of pollution. Allowing for the buying and selling of permits to emit sulfur has been an effective means of reducing sulfur dioxide emissions and subsequent acidic deposition.
Module 49 Stratospheric Ozone Depletion
Explain the benefits of stratospheric ozone and how it forms.
Although ozone is the same gas that is a component of photochemical smog in the troposphere, in the stratosphere it is an important gas that absorbs harmful ultraviolet radiation. Its presence allows for plant and animal life to exist on the surface of Earth.
Describe the depletion of stratospheric ozone.
Chlorine-
Explain efforts to reduce ozone depletion.
International efforts to reduce CFC emissions have helped stratospheric ozone levels to recover. The Montreal Protocol on Substances That Deplete the Ozone Layer is regarded as one of the most successful international agreements of modern times.
Module 50 Indoor Air Pollution
Explain how indoor air pollution differs in developing and developed countries.
Indoor air pollution is a different kind of problem in developing than in developed countries. Cooking over open fires with inadequate ventilation exposes occupants to carbon monoxide in the developing world. Relatively well-
Describe the major indoor air pollutants and the risks associated with them.
Carbon monoxide and particulates are the most harmful aspects of indoor air pollution and account for 4 million deaths annually worldwide. Fifty-