Air Pollution Julieanne Quigley-2.2017

Air Students are sometimes told to stay home from school in Mexico city because the air pollution is so dangerous. At these times, some people wear dust masks when they go outside and hospitals are crowded with people suffering from respiratory problems. Birds sometimes drop out of the trees dead because they cannot escape the toxins!

Air Clean air consists mostly of nitrogen and oxygen gases along with very small amounts of argon, carbon dioxide and water vapor When harmful substances end up in the air at unhealthy levels, the result is air pollution

Air Most air pollution is the result of human activities, but pollutants can come from natural sources as well A volcano for example, can spew clouds of particles into the air and sulfur dioxide can harm animals. Other natural pollutants include: dust, pollen and spores.

Air Pollution A pollutant that is put directly into the air by human activities is called a primary pollutant Soot from smoke Carbon monoxide from cars, trucks and engines Nitrogen oxides from burning fossil fuels Volatile Organic Compounds from solvents, paints and glues Particulate matter from construction, agriculture and fires

Air Pollution A secondary pollutant is formed when a primary pollutant comes into contact with another primary pollutant or with a naturally occurring substance like water vapor and a chemical reaction takes place. These secondary pollutants are hugely responsible for breaking down the ozone layer that protects us from UV rays from the sun

Vehicle Pollution 1/3 of our air pollution comes from gasoline burned by motor vehicles The clean air act and the environmental protect agency have both made laws about emissions allowed from cars and encouraged alternative fuel sources for cars to reduce pollution In 1985 an average car got about 12 miles per gallon and in 2015 the average car got about 30 miles per gallon

Vehicle Pollution In addition to increasing MPG and lowering emissions some other ways to reduce vehicle pollution are: Drive less Carpool Take public transportation Bike Try to work closer to home

Industrial Pollution Many industries and power plants that generate electricity must burn fuel to get the energy they need. In most instances, this is a fossil fuel. Burning fossil fuels causes huge quantities of oxides to be released into the air Electric power plants produce at least 2/3 of all the sulfur dioxide, over 1/3 of nitrogen oxides and 1/3 of particulates that pollute the air

Industry Pollution Some industries also use volatile organic compounds (VOCs), which form toxic fumes. For example manufactures of electronic products, such as TV’s and computers. These manufactures use solvents to clean circuit boards during manufacturing

Industry Pollution The clean air act requires many industries to use “scrubbers” or other pollution-control devices Scrubbers remove some of the more noxious substances that would otherwise foul the air Electrostatic Precipitators are used on smoke stacks and they remove particles before they get into the air

Thermal Inversions As circulation in the atmosphere usually keeps air pollution from reaching dangerous levels. During the day, the sun heats the surface of the earth and the air near it The arm air rises through the cooler air above, carrying pollutants away from the earth’s surface and into the atmosphere

Thermal Inversions Sometimes, however, pollution is trapped near the Earth’s surface by a thermal inversion. Normally, air temperatures decrease with height, but in a thermal inversion, the air above is warmer than the air below. Thermal inversion traps pollutants near the earth’s surface, the warmer air above keeps the cooler air at the surface from moving upward

Thermal Inversion If a city is located in a valley, it has a greater chance of experiencing thermal inversions. Los Angeles, which lies on the pacific coast is surrounded on the other three sides by mountains Los Angeles has frequent thermal inversions that trap smog in the city

Thermal Inversion When air pollution hangs over urban areas and reduces visibility, it is called smog Smog is a term combining the words smoke and fog Smog results from chemical reactions involving sunlight, nitrogen oxides, and hydrocarbons. Pollutants from cars and industries are the main causes of smog Cities that suffer the most from smog have dense traffic and are located in dry, sunny areas: Los Angeles, Denver and Mexico City are well known high smog cities

Effects on Human Health Air pollution can cause serious health problems People who are very young or very old and those with heart or lung problems are the most susceptible to the effects of air pollutants

Chronic Bronchitis and Asthma If a person’s lungs are constantly irritated by pollutants, chromic bronchitis, a persistent inflammation of the bronchial linings may result Constant coughing weakens the bronchial tubes and eventually breathing becomes difficult

Chronic Bronchitis and Asthma Oxides, acids of sulfur and nitrogen are the main irritants that contribute to chronic bronchitis and asthma Asthma is a condition in which the bronchial passages constrict and becomes blocked with mucus. Most asthma is not caused by pollution, people with asthma experience worse symptoms because of pollution

Emphysema and Lung Cancer Air pollution has been linked to emphysema Emphysema results when the air sacs in the lungs lose their elasticity and can no longer push air out of the lungs People with emphysema cannot get enough oxygen and eventually die from long term suffocation

Emphysema and Lung Cancer Lung cancer is another respiratory disease that is linked to air pollution Although cigarette smoke is the major cause of lung cancer, automobile exhaust and particulates (especially asbestos, arsenic and chromium) contribute to lung cancer City-dwellers are 3 to 4 times more likely to develop lung cancer than nonsmoking people in rural areas

Indoor Air Pollution Air pollution is not limited to outdoors, air inside a building is sometimes worse than the air outside American’s spend 89% of their lives inside In buildings where windows are open regularly, pollutants will circulate and pass out of the building… In a building where things are tightly sealed, pollutants accumulate and reach higher levels than they could outdoors

Indoor Air Pollution Buildings with particularly poor air quality are said to have “sick-building syndrome”. For example, in Florida, a brand new tightly sealed court house had to be abandoned when half of the people who worked there developed allergic reactions to fungi that were growing in the air condition ducts, ceiling tiles, carpets and furniture

Indoor Air Pollution Radon Gas- radon gas is invisible, tasteless and odorless… it is also radioactive. Radon is one of the elements produced by the radioactive decay of uranium, which occurs naturally in the earth Houses built over radon heavy areas can have radon build up inside the house Radon gas can destroy the genetic material in cells lining the air passages and can lead to cancer.

Indoor Air Pollution Asbestos- a combination of several fibers containing silica that are valued for their strength and resistance to heat… For years asbestos was used in building/construction Exposure to asbestos has been known to cause mesothelioma a rare lung cancer related to breathing in these fibers Schools in the US have spent over 40 billion dollars removing asbestos from schools!

Acid Precipitation Acid precipitation is highly acidic precipitation (rain, sleet or snow) that results from the burning of fossil fuels When fossil fuels are burned, they release oxides of sulfur and nitrogen as by-products When the oxides combine with water from the atmosphere they create nitric acid and sulfuric acid

Acid Precipitation The acid precipitation can kill living things. Precipitation considered to be acid precipitation is anything with a pH lower than 5.6. The pH of pure water is 7.0

Acid Precipitation Animals are adapted to live in an environment with a particular pH If acid precipitation falls on a lake and changes the pH of the water aquatic plants, fish, amphibians and other animals die Acid shock is a sudden increase in pH due to snow melting in the spring. Acid shock kills eggs and many species lose their offspring for that year

Acid Precipitation Forest ecosystems are also affected by acid precipitation. Trees, like other organisms, can only tolerate a specific pH range If they water they take up through their roots is too acidic, they will die Acid precipitation can also burn off the leaves and needles of plants.

Acid Precipitation The biggest problem with controlling acid precipitation is that where the pollution is released is almost never where the acid precipitation falls. Wind and clouds carry the polluted water to other areas around the world. This is causing a serious problem all over the world For example: pollution in Denver can fall as acid rain all over the eastern US