Acid Rain

Acid Rain is caused by nitrogen and sulphur oxide pollution. These chemicals can be found in nature but 95% of the nitrogen and sulphur oxide pollution comes from coal fired power plants, fuel combustion in vehicles and metal smelting. These two pollutants combine and form sulphuric acid, which dissolves easily into moisture. They form acidic water droplets and can be carried very far by wind before falling to the earth as rain, fog or snow. Sometimes the sulphuric acid falls to the ground in gas form as a grain of salt. It still has the same effect as other acid rain because it eventually is absorbed by the ground or water where it falls.

When the acid rain (more commonly called acid deposition) falls into water it changes the natural balance between alkaline and acidity in the water, called the water's pH level. The pH level is normally 6-8 but acid rain can alter that level to as low as 4 pH! As the water level approaches...

• 6.0- Crustaceans, plankton and some insect species begin to disappear.
• 5.0- There is a major change in the plankton composition and less desirable species of water plants and mosses move into the stream. This affects fish populations and the most desirable sport fishing species are the most vulnerable.
• Below 5.0- The stream is devoid of fish, the bottom is covered in undecayed material and there aren't many plants around the shore either.

All this triggers a chain reaction in animal species. Animals that feed on fish or water plants are affected, then their predators are affected and the acid rain that affected the stream has now affected the entire food chain in the ecosystem. Acid rain also makes it harder for animals to reproduce.

On land, acid rain can effect plants by altering the surface of their leaves and leaving them more susceptible to disease. It can also remove nutrients from the soil and make it harder for plants to grow.

Acid Rain affects humans too. It has been linked with breathing problems such as asthma and it increases the levels of other pollutants in drinking water. Acid Rain is corrosive and it cause billions of dollars of damage every year to buildings in Canada and the US. It also costs billions of dollars in lost profit in the fishing, logging and maple syrup industries because it destroys fish habitat and forests.

Progress has been made on acid rain in the last 20 years but much more needs to take place. Ways you can help are to limit your use of electricity, and limit your driving. 40% of nitrogen pollution comes from transportation and 10% is from sources in your home. Most of the problems of acid rain come from the industrial areas of southern Ontario and the Ohio Valley of the US. Prevailing winds blow spread the smog around eastern Canada and the US. If everyone works together we can put a stop to Acid Rain once and for all.