Chapter 18 Air Pollution Alyssa Weibe 4/28/14

What is the nature of the atmosphere The two innermost layers of the atmosphere are the troposphere, which supports life, and the stratosphere, which contains the protective ozone layer. South Asia had this massive thick set of clouds hover over called “brown clouds” and the clouds contained small particles of dust, smoke, and ash resulting from drought and the clearing and burning of forests for planting crops. These brown clouds do not stay put, they move across continents within three to four days.

The atmosphere consists of several layers. We live under a thin blanket of gases The lower layers have more gases in them than upper layers do the air we breathe at sea level has a higher density than the air we would inhale on top of a high mountain About 99% of the volume of air you inhaled consists of two gases: nitrogen (78%) and oxygen (21%). The UV filtering effect of ozone in the lower stratosphere allows us and other forms of life to exist on land and helps to protect us from sunburn, skin and eye cancers, cataracts, and damage to our immune systems Rising and falling air currents, winds, and concentrations of CO2 and other greenhouse gases in the troposphere play a major role in the planet’s short-term weather and long-term climate.

Vocabulary Atmospheric pressure- the force, or mass, per unit area of a column of air Troposphere- the atmospheric layer closest to the earths surface Stratosphere- atmospheres second layer

What are the major outdoor air pollution Pollutants mix in the air to form industrial smog, primarily as a result of burning coal, and photochemical smog, caused by emissions from motor vehicles, industrial facilities, and power plant

Air pollution comes from natural and human sources Natural sources include wind-blown dust, pollutants from wildfires and volcanic eruptions, and volatile organic chemicals released by some plants. almost any chemical in the atmosphere can become a pollutant if it occurs in a high enough concentration Some pollutants in the atmosphere combine to form other pollutants high concentrations of cars and factories, urban areas normally have higher outdoor air pollution levels than rural areas have There is no place on the planet that has not been affected by air pollution caused mostly by the burning of forests and the use of fossil fuels

Carbon monoxide can combine with hemoglobin in red blood cells, which prevents the normal binding of oxygen with hemoglobin molecules This can contribute to human health problems such as heat exhaustion and to the reduction of food supplies in some areas, while causing water shortages, prolonged drought, or excessive flooding in other areas. About one- third of the SO2 in the atmosphere comes from natural sources as part of the sulfur cycle

What is acid deposition and why is it a problem? Acid deposition is caused mainly by coal- burning power plants and motor vehicle emissions, and in some regions it threatens human health, aquatic life and ecosystems, forests, and human-built structures

Most coal-burning power plants, ore smelters, and other industrial facilities in more-developed countries use tall smokestacks to vent the exhausts from burned fuel, which contain sulfur dioxide, suspended particles, and nitrogen oxides, high into the atmosphere where wind can dilute and disperse them Most dry deposition occurs within 2–3 days of emission, fairly near the industrial sources, whereas most wet deposition takes place within 4–14 days in more distant downwind areas. Acid deposition is mostly a regional air pollution problem in areas that lie downwind from coal-burning facilities and from urban areas with large numbers of cars In the United States, older coal-burning power and industrial plants without adequate pollution controls, mostly located in the Midwest, emit the largest quanti- ties of SO2 and other pollutants that cause acid depo- sition

Acid deposition damages statues and buildings, contributes to human respiratory diseases, and can leach toxic metals from soils and rocks into lakes used as sources of drinking water. Acid deposition often along with other air pollutants such as ozone can harm crops, especially when the soil pH is below 5.1. You can prevent acid deposition by, reducing coal use, burn low-sulfur coal, an tax emissions of SO2 According to the U.S. National Emissions Inventory, between 1980 and 2008, air pollution laws in the United States helped to reduce sulfur dioxide emissions from all sources in the United States by 56% and nitrogen oxide missions by 40%.

What are the major indoor air pollution problems The most threatening indoor air pollutants are smoke and soot from the burning of wood and coal in cooking fires (mostly in less-developed countries), cigarette smoke, and chemicals used in building materials and cleaning products.

Indoor air pollution is a serious problem The most threatening air pollutant are smoke and soot from the burning of wood, and chemicals A serious problem in developed areas because of the chemicals used in the building materials and products Living organisms and their excrements can also pollute indoor air Another living source of indoor air pollution is toxic airborne spores of fungal growths such as molds and mildew that can cause headaches and allergic reactions and aggravate asthma and other respiratory diseases.

When radon gas from such deposits seeps upward through the soil and is released outdoors, it disperses quickly in the air and decays to harmless levels. About 90% of radon-related lung cancers occur among current or former smokers 1 of every 5,000 people who live in manufactured homes for more than 10 years are likely to develop cancer from formaldehyde exposure

What are the health effects of air pollution Air pollution can contribute to asthma, chronic bronchitis, emphysema, lung cancer, heart attack, and stroke.

Your body’s natural defenses against air pollution can be overwhelmed Your respiratory system (Figure 18-21) has a number of ways to help protect you from air pollution. Prolonged or acute exposure to air pollutants, including tobacco smoke, can overload or break down these natural defenses

Air pollution is a big killer at least 2.4 million people worldwide die prematurely each year from the effects of air pollution According to recent EPA studies, each year, more than 125,000 Americans get cancer from breathing soot- laden diesel fumes emitted by buses and trucks

How should we deal with air pollution Legal, economic, and technological tools can help us to clean up air pollution, but the best solution is to prevent it.

Laws and regulations can reduce outdoor air pollution The TRI law passed and required power plants, mines, factories, and chemical manufacturers to report release and waste management We can use the market place to reduce outdoor air pollution reducing pollutant emissions has been to allow producers of air pollutants to buy and sell government air pollution allotments in the marketplace. There are many ways to reduce outdoor air pollution You can prevent motor vehicle air pollution by walking, a bike, or mass transit

Reducing indoor air pollution should be a priority Little effort has been devoted to reducing indoor air pollution even though it poses a much greater threat to human health than does outdoor air pollution. In more-developed countries, where VOCs present the greatest indoor air pollution threats, houseplants may provide some relief You can prevent indoor air pollution by ban indoor smoking, prevent radon infiltration, and use less polluting cleaning agents, paints, and other products

3 big ideas Outdoor air pollution, in the forms of industrial smog, photochemical smog, and acid deposition, and indoor air pollution are serious global problems. Each year, at least 2.4 million people die prematurely from the effects of air pollution; indoor air pollution, primarily in less-developed countries, causes about two-thirds of these deaths. We need to put our primary emphasis on preventing outdoor and indoor air pollution throughout the world.