Explain how acid deposition occurs?

Acid deposition occurs when acid-forming pollutants in the air are deposited on the earth’s surface, by emissions of carbon dioxide, sulfur dioxide and nitrogen oxides which react with the water molecules in the atmosphere to produce acids that return to the earth in four ways:

• mixed with rain to form acid rain;

• mixed with snow or hail, which form acids as they melt;

• as particles of solid matter, which form an acid when they mix with water in lakes and rivers; and

• as dry deposition of gases and particles.

Acidic soils cannot neutralize acid; therefore acids build up faster in these soils.

Acid rain produces complex changes in normal soil chemistry. Minerals like calcium, magnesium, potassium and sodium are leached from the soil and carried away. Toxic metals like aluminum, manganese, mercury, cadmium and lead become more soluble by the chemical action of the acids.

It can have harmful effects on plants, aquatic animals, and infrastructure.

You can help by reducing further contamination:

• Keeping industrial and vehicle emissions to minimum (“Right” size your vehicle, Reduce the amount of driving, Trade an old beat-up car in for a new vehicle)

• Keeping your pollution control devices in good working order

• Reducing, reusing and recycling products to help reduce the amount of pollution generated in manufacturing/production.

• Turning off lights and computers when they are not being used

:)