What is acid rain
Gasoline-powered vehicles and coal- and oil-burning furnaces release sulfur dioxide, nitrogen oxide, and hydrocarbons into the air. These contaminants are known as primary pollutants. Sunlight reacts with these pollutants to form ozone, which, in turn, reacts with sulfur and nitrogen oxide to produce sulfuric acid and nitric acid. These sulfuric and nitric acids are stored in the droplets of water that make up clouds. In this form, the acids are carried great distances by the wind, and fall as acid rain.

Dying Forests
Millions of acres of forests have suffered from the effects of acid rain. Coniferous trees (cone-bearing evergreens) seem to be the hardest hit. Sulfur dioxide kills many trees by depleting the nutrients in the soil. Even slight damage to trees can easily kill them because it reduces their resistance to frost, fungi, and deadly pests. Studies conducted in the United States indicate that even in forests that show no external signs of acid rain damage, pollution is limiting their growth.

Poisoned Wildlife
Huge quantities of fish have died in Norway, Sweden, Scotland, Canada, and the eastern United States. Most have been killed by aluminum released into the water by acid rainfall. This, in turn, has affected fish-eating birds, such as the osprey, black- and red-throated divers, common tern, and goosander. These birds, along with the insect larbae on wich they feed, are now absent from many streams in which they were once common. Aluminum also causes songbirds like the blue-throat, reed bunting, and wilow warbler to lay eggs with thin shells, reducing their breeding success. Dead eggs and young found in surface water indicate that many aquatic vertebrates, including several species of frog and toad, are dying as well.

Acid Rain - The Global Facts
The term "acid rain" was first coined in Britain to describe conditions in Manchester 100 years ago. Today, Britain releases almost as much sulfur dioxide into the air as does all of western Europe combined. Forests and watercourses in Britain have been adversly affected by acid rain. The number of countries that are suffering from the effects of acid rain continues to grow. Sweden's lakes have acidified, and 4,000 of them have completely lost their fish stocks. In Norway, an estimated 60 percent of fish stocks have been lost because of acidified lakes. In Canada, an estimated 48,000 lakes are currently threatened. In the United States, acid rain poses a severe threat to both fish and waterfowl expecially on the East Coast.