Air Quality 2006 Prentice Hall Science Explorer- Earth Science

Pollution  Pollutants are harmful substances in the air, water, or soil.  Air that contains harmful particles and gases is said to be polluted.  Pollutants are harmful substances in the air, water, or soil.  Air that contains harmful particles and gases is said to be polluted.

Sources of Pollution Some air pollution occurs naturally. But many types of air pollution are the result of human activities.

Natural Sources of Pollution G Natural processes add particles to the atmosphere. Some examples of natural sources would be: G Forest fires, soil erosion, and dust storms release a great deal of smoke and dust into the air. G The wind carries particles of mold and pollen. G Erupting volcanoes spew out clouds of dust, ash and poisonous gases. G Natural processes add particles to the atmosphere. Some examples of natural sources would be: G Forest fires, soil erosion, and dust storms release a great deal of smoke and dust into the air. G The wind carries particles of mold and pollen. G Erupting volcanoes spew out clouds of dust, ash and poisonous gases.

Human Activities as Sources of Pollution »Most pollution comes from the burning of fossil fuels, such as coal, oil, gasoline, and diesel fuel. Almost 1/2 of this pollution comes from motor vehicles. »Burning fossil fuels produces a variety of pollutants, including carbon monoxide, nitrogen oxides, and sulfur oxides. »Farming and construction can send soil and dust in the air.

Smog  Smog is a term created from combining the words smoke and fog.  The two types of fog are London-type smog and Photochemical smog  Smog is a term created from combining the words smoke and fog.  The two types of fog are London-type smog and Photochemical smog

London-Type Smog »In the 1900’s London’s air was so polluted with soot from factories burning coal and homes being heated by coal that the city was dark and dirty. »This coal smoke combined with humidity in the air creates this type of smog.

Photochemical Smog Photo- means “light”. Photochemical smog is formed by the action of sunlight on pollutants such as hydrocarbons and nitrogen oxides. These chemical react to form a brownish mixture of ozone and other pollutants.

Acid Rain  Rain is naturally slightly acidic, but rain that contains more acid than normal is known as acid rain.

How Does Acid Rain Form? F Acid rain forms when sulfur is produced from the burning of coal. This sulfur combines with oxygen in the air producing sulfur oxide. When nitrogen oxides and sulfur oxides combine with water they form nitric acid and sulfuric acid. Rain, sleet, snow and fog carries these two acids to trees and lakes. F Acid rain is can be strong enough to damage the surface of buildings and statues. F Acid rain can make water so acidic that plants, amphibians, fish and insects can no longer survive. F Acid rain forms when sulfur is produced from the burning of coal. This sulfur combines with oxygen in the air producing sulfur oxide. When nitrogen oxides and sulfur oxides combine with water they form nitric acid and sulfuric acid. Rain, sleet, snow and fog carries these two acids to trees and lakes. F Acid rain is can be strong enough to damage the surface of buildings and statues. F Acid rain can make water so acidic that plants, amphibians, fish and insects can no longer survive.

Improving Air Quality In the US, the federal and state governments have passed a number of laws and regulations to reduce air pollution. The Environmental Protection Agency (EPA) monitors air pollutants in the US. Air quality in this country has generally improved over the last 30 years. What are some ways we can help improve air quality?