Topic 16: Air Quality

What is the major function of stratospheric ozone? A. Ozone molecules reflect outgoing heat from Earth, keeping the surface warm enough for life. B. Ozone molecules protect life on Earth's surface by absorbing incoming ultraviolet (UV) radiation from the sun. C. Ozone binds with particulate matter to make it settle back to Earth faster. D. Ozone molecules absorb excess carbon dioxide molecules. E. Ozone molecules slow the formation of acid rain molecules.

B. Stratospheric ozone molecules protect life on Earth's surface by absorbing incoming ultraviolet (UV) radiation from the sun. Ozone does not prevent heat from escaping Earth. Pollutants such as particulate matter, carbon dioxide, and acid rain occur in the troposphere, which is lower than the stratosphere.

What is the main source of stratospheric-ozone-depleting pollutants? A. Human-made chlorofluorocarbons B. Volcanoes C. Lead D. Carbon dioxide E. Radon

A. Years of research by hundreds of scientists have shown that human-made chlorofluorocarbons are the major source of stratospheric-ozone-depleting pollutants.

In temperate latitudes, surface winds tend to blow __________. A. toward the equator B. away from the equator C. toward the west D. vertically E. toward mountain ranges

B. In temperate latitudes, surface winds tend to blow away from the equator. Cool air descends at 30° north and south. Some of this air blows back toward the equator, and some of this air blows in the other direction, toward 60° north or south.

One reason areas near the equator get more rainfall than areas about 30 degrees north or south do is that __________. A. air near the equator rises, warming as it rises and increasing its ability to hold water vapor B. air near the equator rises, cooling as it rises and losing its ability to hold water vapor C. air near the equator sinks, causing rain to fall D. air near the equator is more likely to be above warm water, so it is easy to pick up water vapor

B. One reason areas near the equator get more rainfall than areas about 30 degrees north or south do is that air near the equator rises, cooling as it rises and losing its ability to hold water vapor. As the equator is known for its tropical warmth, this air is continually rising and causing frequent rain events. Warm water also exists around 30°, and yet these areas are often dry. Therefore, the ability to pick up water vapor from the water is not a major factor in rainfall determination.

What is not a major impact of lead pollution on human health? A. All of the answers are a major impact of lead pollution on human health. B. Toxic at low concentrations C. Accumulates in body tissues D. Brain damage E. Damage to the nervous system

A. All of the answers are major impacts of lead pollution on human health. Lead from combustion of leaded gasoline, battery manufacturing, and smelters can cause all of these effects, and as a consequence, the use of leaded gasoline has been banned in most countries, and global emissions have decreased drastically.

Much of the damage to forests from acid precipitation is due to chemical interactions with the soil, which is caused by __________. A. insoluble toxic metal ions, such as aluminum, becoming soluble, which builds up concentrations in the soil and negatively affects the roots of plants B. increasing the amount of leaf litter falling to the ground C. increasing invasive species that live in the soil D. increasing the amount of basic nutrients, such as calcium and magnesium

A. Although nutrients such as nitrogen and sulfur may initially increase in the soil due to acid precipitation, these chemicals leach out buffering chemicals, such as calcium and magnesium salts. These buffering chemicals can no longer neutralize the acid rain, so that heavy metals, such as aluminum, become soluble, and are dissolved in the soil. These higher levels damage roots, reducing their ability to take up water and nutrients. Acid precipitation leaches nutrients and minerals from the soil and vegetation, damaging leaves and causing defoliation and reduced leaf litter that falls to the ground. Acid precipitation does not affect soil by increasing invasive species. Acid precipitation leaches out (removes) basic nutrients, such as calcium and magnesium salts from soil.

A ________ occurs when a layer of cool air is trapped under a layer of warm air in the troposphere. A. thermal (temperature) inversion B. low-pressure system C. high-pressure system photochemical effect convection current

A. In the troposphere, air becomes cooler as altitude increases. Sometimes, however, a thermal (or temperature) inversion occurs when a layer of cool air is trapped under a layer of warm air in the troposphere. This usually occurs on cold nights when air near the ground cools and is trapped. In a low-pressure system, warm air rises, expands, and cools, and precipitation occurs. A high-pressure system contains air that cools, descends, and spreads, bringing fair weather. A photochemical effect occurs when sunlight helps form air pollutants. A convection current results from differences in gas density, which results from differences in air temperature, where warm air rises and creates vertical currents.

Approximately 80 percent of our atmosphere is made up of which of the following? A. N2 B. O2 C. CO2 D. H2O

A. Nitrogen gas (N2) makes up 80 percent of the atmosphere. By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.

Which form of pollution would be decreased by using catalytic converters on cars? A. Photochemical smog B. Industrial smog C. Sulfur dioxide D. Stratospheric ozone E. All of these would be reduced.

A. Of the listed pollutants, photochemical smog is the only pollutant best controlled by catalytic converters. Photochemical smog is produced when pollutants from automobile exhausts are acted upon by sunlight. Industrial smog is controlled by smokestack scrubbers, while sulfur dioxide is controlled by technologies used on coal-burning electrical facilities. Ozone in the stratosphere is not a pollutant.

When discussing air pollution, what is a primary pollutant? A. A harmful substance produced when pollutants interact or react with other atmospheric components B. A pollutant that can cause harm directly or can react with other chemicals to form harmful substances C. Pollution formed from the combination of sulfur and water D. A pollutant that has been formed by sunlight acting on chemicals E. Fine droplets of water that reflect sunlight back into space

B. A primary pollutant is a pollutant that can cause harm directly or can react with other chemicals to form harmful substances. Primary pollutants may undergo further reactions in the atmosphere to produce secondary pollutants. Acid rain is a secondary pollutant formed when sulfur dioxide in the atmosphere reacts with oxygen and water to produce sulfuric acid. Aerosols are fine droplets of pollutants that reflect sunlight back into space and cool the atmosphere and Earth's surface.

The climate in an area is determined primarily by analyzing __________. A. the area's global longitude and altitude B. the area's average annual temperature and precipitation and annual variation in temperature and precipitation C. the area's species composition and average annual temperature and precipitation D. the area's altitude and average annual temperature and precipitation throughout the year

B. The climate in an area is determined primarily by analyzing the area's average annual temperature and precipitation and annual variation in temperature and precipitation, as well as the pressure, humidity, cloudiness, and wind. Climate is dictated by both the average and variation of temperature and precipitation in an area. Altitude does affect both of these factors, but not all altitudes have the same effect on temperature and precipitation. Therefore, directly examining the temperature and precipitation is a more reliable measure. The Earth's longitude has no effect on these factors, but the latitude (N to S) does. Species composition is a result of climatic factors, not the cause of them.

What is a major consequence of a thermal inversion? A. Pollutants mix vertically. B. Pollutants are diluted. C. Air pollutants become trapped and accumulate below the inversion layer. D. Convection currents are slowed down. E. A warm front forms.

C. A major consequence of thermal inversions is that air pollutants become trapped and accumulate below the inversion layer. With thermal inversions, vertical mixing does not occur, and air pollutants are not diluted but become trapped below the inversion layer. Under normal conditions, warm air rises, which allows pollutants to be carried upward and diluted. Convection currents result from differences in air temperatures, where warm air rises and creates vertical currents. A warm front forms when a mass of warm, moist air replaces a mass of cooler, drier air.

Compared with 1970, what happened to emissions of the five primary pollutants in the United States in 2011? A. They are much higher. B. They are about the same. C. They have been significantly reduced. D. We don't know; we didn't take measurements in 1970. E. They are so low, we no longer monitor them.

C. In 2011, U.S. emissions of carbon monoxide, nitrous oxides, volatile organic compounds, sulfur dioxide, and particulate matter have been significantly reduced compared to 1970.

Where would a person be most exposed to photochemical smog? A. New York City, New York B. Pittsburgh, Pennsylvania C. Los Angeles, California D. Cleveland, Ohio E. London, England

C. Photochemical smog is produced when pollutants from automobile exhausts are acted upon by sunlight and occurs in sunny, warm areas such as Los Angeles, California. New York City, Pittsburgh, Cleveland, and London are cities in colder, wetter climates that often use coal in industrial processes and home heating.

Which federal agency is responsible for tracking trends in national emissions of primary pollutants from all sources? A. USDA B. FDA C. EPA D. DOI E. DOD

C. The U.S. Environmental Protection Agency (EPA) is responsible for tracking trends in national emissions of primary pollutants, regardless of the source of emissions. The U.S. Department of Agriculture (USDA), the Food and Drug Administration (FDA), the Department of the Interior (DOI), and the Department of Defense (DOD) are federal agencies that have other responsibilities.

What is the main difference between climate and weather? A. Weather typically describes a larger area than climate. B. Climate typically describes shorter-term conditions. C. Climate typically describes longer-term conditions. D. Weather includes temperature, and climate does not. E. Climate is primarily a term used by ecologists; weather is primarily a term used by the general public.

C. The main difference between climate and weather is that climate typically describes longer-term conditions. Climate is defined by the longer-term averages of things like temperature and precipitation levels rather than shorter-term events like weather. Both terms are used by ecologists and include descriptions of temperature.

Which region on Earth receives the most solar radiation per unit area over a year? A. North Pole B. South Pole C. 30° N and 30° S latitude D. Equator

D. Due to the tilt of the Earth's rotational axis, the equator is the region on Earth that receives the most solar radiation per unit area over a year. This tilt also makes it so that the poles receive the least solar radiation, and the 30° latitudes receive an intermediate level of solar radiation throughout the year.

Generalized global air circulation and precipitation patterns are caused by __________. A. air masses that are dried and heated over continental areas that rise, cool aloft, and descend over oceanic areas followed by a return flow of moist air from ocean to land, delivering high amounts of precipitation to coastal areas B. polar, cool, moist high-pressure air masses from the poles that move along the surface, releasing precipitation along the way to the equator, where they are heated and dried C. the revolution of Earth around the sun D. rising, warm, moist air masses that cool and release precipitation as they rise and then, at high altitude, cool and sink back to the surface as dry air masses after moving north or south of the tropics E. mountain ranges that deflect air masses containing variable amounts of moisture

D. Generalized global air circulation and precipitation patterns are caused by rising, warm, moist air masses that cool and release precipitation as they rise and then, at high altitude, cool and sink back to the surface as dry air masses after moving north or south of the tropics. These patterns are referred to as Hadley cells in which warm wet air masses release precipitation as they rise and move away from the equator. This is the cause of the massive amounts of rainfall in the tropics. If the air masses were emerging from the poles, one would find very wet northern and southern areas and dry areas along the equator. The tilt of Earth combined with its movement around the sun is the cause of seasons, but not global air circulation. Mountain ranges exhibit this same effect of causing moist air masses to release precipitation as these air masses move up and over the mountains, but they are not deflecting them in any significant manner at a global scale.

In tropical areas, surface winds tend to blow toward the equator because __________. A. air flows "downhill" from the North Pole B. Earth's rotational speed is fastest at the equator C. the oceans are broadest at the equator D. equatorial air is heated by the sun and rises E. this is a very rainy area

D. In tropical areas, surface winds tend to blow toward the equator because equatorial air is heated by the sun and rises, creating an area of calm or very light winds known as the doldrums. As warm equatorial air rises, it cools and releases much of its water content. After losing their moisture over equatorial zones, high-altitude air masses spread away from the equator until they cool and descend again at latitudes of about 30° north and south.

Which of the following is not a primary pollutant? A. Sulfur dioxide B. Carbon monoxide C. Nitrogen oxide D. Industrial smog E. Lead

D. Industrial smog is not a primary pollutant. It is a secondary pollutant that is formed when coal is burned and is a combination of soot, sulfur dioxide, and carbon monoxide. Carbon monoxide is released by the incomplete combusion of fossil fuels. Nitrogen oxides are released from combustion in vehicle engines. Sulfur dioxide is released from burning coal for electrical generation. Lead is a primary pollutant that comes from burning leaded gasoline.

What is a major health effect of particulate air pollution? A. Death from lack of oxygen delivery to tissues B. A variety of cancers C. Radon poisoning D. Effects on the respiratory system E. Brain damage in children

D. Particulate air pollution has major effects on the respiratory system. If inhaled, particulate matter such as dust and soot can reduce lung function and affect respiration. Carbon monoxide binds to hemoglobin in the blood and blocks oxygen delivery to cells. Toxic chemicals such as benzene and asbestos can cause cancer. Radon is an invisible and odorless radioactive gas that can accumulate inside homes. Lead can cause brain damage in children.

Which major international treaty agreed to phase out production and use of CFCs to protect stratospheric ozone? A. Kyoto Protocol B. Clean Air Act C. National Ambient Air Quality Standards D. Montreal Protocol E. Ozone Protection Act

D. The Montreal Protocol, signed by 196 UN member countries, agreed to phase out production and use of CFCs to protect stratospheric ozone. They agreed to scale back CFC production 50% by 2000; an amendment to the protocol in 1990 agreed to phase out CFCs by 2000 in developed countries and by 2010 in developing countries. The Kyoto Protocol addressed reducing greenhouse gas emissions responsible for climate change. The Clean Air Act and National Ambient Air Quality Standards (NAAQS) deal with U.S. air pollution. There is no Ozone Protection Act.

Which statement about radon is not correct? A. It is a colorless, oderless radioactive gas. B. You have to test the building's air to tell if radon is entering a building. C. Radon kills thousands of people each year in the U.S. alone. D. It is a leading cause of cancer in the developed world. E. It is a major problem in developing nations, because very few people in developed nations are exposed to radon.

E. Buildings in developed nations are built to be more energy efficient, which means they often have windows that do not open, and have less ventilation. Also, people in developed nations spend most of their time indoors. People in developing nations spend more time outside, and their buildings have windows that can open, and many do not have basements, where radon can seep in. Radon is the second-leading cause of lung cancer in the developed world, and causes 15% of lung cancer cases worldwide. Radon is a colorless, odorless radioactive gas, which results from the natural decay of fissionable material (uranium) in rocks and soil. The only way to see if radon is entering a building is to sample the air with a test kit. Radon kills at least 21,000 people each year in the U.S.

Which secondary air pollutant is found mainly around cities and is formed from burning coal or oil, which releases a combination of soot, carbon monoxide, and sulfur dioxide? A. Photochemical smog B. Carbon monoxide C. Lead D. Tropospheric ozone E. Industrial smog

E. Industrial smog is a secondary pollutant that is found mainly around cities and is formed when coal is burned, releasing soot, sulfur dioxide, and carbon monoxide. Photochemical smog is formed when certain primary pollutants interact with sunlight. Carbon monoxide is a primary pollutant released by the incomplete combusion of fossil fuels. Lead, a primary pollutant, is released from burning lead-containing gasoline and smelting operations. Tropospheric ozone is a pollutant in photochemical smog.

Acid deposition is formed when _____ and _____, released from combustion of fossil fuels, reacts with oxygen and water in the atmosphere. A. tropospheric ozone and nitrogen dioxide B. carbon monoxide and lead C. particulate matter and lead D. heavy metals and photochemical smog E. sulfur dioxide (SO2) and nitrogen oxide (NOx)

E. Sulfur dioxide (SO2) and nitrogen oxide (NOX) gases come from burning fossil fuels in coal-fired power plants and vehicle exhaust, and are the most abundant acidifying pollutants. They react with water and oxygen in the atmosphere to produce sulfuric and nitric acids. Acid deposition negatively affects forests and lakes. Tropospheric ozone is a secondary pollutant, created by the reaction of nitrogen oxides and volatile carbon-containing chemicals in the presence of sunlight. This pollutant can cause respiratory problems. Nitrogen dioxide is a source of acid deposition, because they combine with oxygen and hydrogen in the air to form nitric acid. Carbon monoxide is a colorless, odorless gas produced by the combusion of fuel. It is hazardous because it binds to the hemoglobin in red blood cells, and can cause death. Lead is a heavy metal that enters the atmosphere as a particulate pollutant. It accumulates in body tissues and can damage the nervous system. Particulate matter, composed of small, suspended particles in the air, include dust, soot, sulfates, and nitrates. Small particles can damage the lung, heart, and brain. Lead is a heavy metal that enters the atmosphere as a particulate pollutant. It accumulates in body tissues and can damage the nervous system. Heavy metals, including lead and mercury, are toxic to humans and other animals, and are released from the combustion of fossil fuels, waste incineration, and metal smelting. Heavy metals can accumulate to toxic levels, and can cause death. Photochemical smog is created when sunlight drives certain chemical reactions between primary pollutants and compounds in the atmosphere. It contains NO2, and appears as a brownish haze over cities.