Acid PrecipitationAcid Precipitation

Environmental ScienceEnvironmental Science

What is Acid Precipitation?What is Acid Precipitation?

Rain, sleet, or snow that Rain, sleet, or snow that contains a high contains a high concentration of acid concentration of acid because of pollution in because of pollution in the atmosphere the atmosphere

SOSO22 and NO and NO22 combine combine

with water in the with water in the atmosphere to create atmosphere to create acid precipitationacid precipitation

How is acidity measured?How is acidity measured?

pH is a number that indicates the acidity of a solutionpH is a number that indicates the acidity of a solution

A pH of 7 is neutral, a pH of less than 7 is acidic, and A pH of 7 is neutral, a pH of less than 7 is acidic, and a pH of greater than 7 is basic.a pH of greater than 7 is basic.

How is acidity measured?How is acidity measured?

Normal precipitation is slightly acidic because Normal precipitation is slightly acidic because atmospheric carbon dioxide dissolves into the atmospheric carbon dioxide dissolves into the precipitation and forms carbonic acid.precipitation and forms carbonic acid.

Precipitation is considered acid precipitation if Precipitation is considered acid precipitation if it has a pH of less than 5.0it has a pH of less than 5.0

How acid precipitation effects plants How acid precipitation effects plants and soiland soil

Acid precipitation can cause a drop in the pH in soil Acid precipitation can cause a drop in the pH in soil or water – called or water – called acidificationacidification

Nutrients in the soil are dissolved and wash awayNutrients in the soil are dissolved and wash away

Aluminum and other toxic metals are more easily Aluminum and other toxic metals are more easily absorbed by plants – causes root damageabsorbed by plants – causes root damage

SOSO22 in water vapor can clog openings in plant leaves in water vapor can clog openings in plant leaves

Acid Precipitation and Aquatic Acid Precipitation and Aquatic EcosystemsEcosystems

If the water’s pH changes, it can kill aquatic If the water’s pH changes, it can kill aquatic organismsorganisms

Acid precipitation also can cause aluminum to Acid precipitation also can cause aluminum to leach out of the soil and into a lake.leach out of the soil and into a lake.

The aluminum accumulates in the gills of fish The aluminum accumulates in the gills of fish and interferes with oxygen and salt exchange and interferes with oxygen and salt exchange so the fish slowly suffocate.so the fish slowly suffocate.

Acid Precipitation and Aquatic Acid Precipitation and Aquatic EcosystemsEcosystems

Acid shockAcid shock – when large amounts of highly – when large amounts of highly acidic run off enters an aquatic ecosystemacidic run off enters an aquatic ecosystem Most often happens when snow melts in the spring Most often happens when snow melts in the spring

or heavy rains after a droughtor heavy rains after a drought

Causes fish to die and those that don’t die lay Causes fish to die and those that don’t die lay fewer eggs and most of the eggs don’t hatchfewer eggs and most of the eggs don’t hatch

The offspring that do hatch often have birth The offspring that do hatch often have birth defects and cannot reproducedefects and cannot reproduce

Acid Precipitation and HumansAcid Precipitation and Humans

Acid Precipitation releases aluminum and Acid Precipitation releases aluminum and toxic metals into the soil that gets into crops, toxic metals into the soil that gets into crops, water and fish.water and fish.

Research also indicates a relationship between Research also indicates a relationship between large amounts of acid precipitation and large amounts of acid precipitation and respiratory problems in childrenrespiratory problems in children

International CooperationInternational Cooperation

One problem in controlling acid precipitation One problem in controlling acid precipitation is that pollutants can be release in one place is that pollutants can be release in one place and fall hundreds of miles awayand fall hundreds of miles away It can be especially difficult to solve on an It can be especially difficult to solve on an

international levelinternational level

Canada and the United States signed the Canada and the United States signed the Canada-U.S. Air Quality Agreement in 1991. Canada-U.S. Air Quality Agreement in 1991.