Acid Rain — Our Struggling Lakes and Forests
Rain might seem like the cleanest source of water on Earth — after all, the only place it has been is in the clouds. However, rain and snow are affected by what they pass through on their way to the ground. Some factories release nitrogen and sulfur from their smokestacks. This mixes with falling rainwater and forms weak nitric and sulfuric acids. Then the rain (or snow) carries the acid to the ground, into lakes, streams, and forests. It changes the pH, making the soil and water more acidic than they would be naturally. Scientists call this acid rain. Acid rain can make the soil too acid for some plants to grow and slow the growth of trees. In lakes and streams it can make the water environment too acid for fish, frog, and salamander eggs to hatch. If lakes and ponds become acid enough they will eventually become completely lifeless.
Don't Lower Your pHAcidity is measured on a pH scale. Something with a pH of 1 is the most acid and something with a pH of 14 the most base (or alkaline). Pure water is considered to be neutral (it has a pH of 7). Normal rainwater has a pH of about 6. That is a little acidic. That is because even pure rainwater falls through carbon dioxide in the air. Rain with a pH of less than about 5.3 is considered acid rain. Rain in the northeastern states has a pH between 4 and 5. This is serious acid rain.
How does acid rain affect plants? Try this experiment to see.
Plant 3 bean seeds in three separate pots, place them in the window and let them grow. When all three plants are about 4 inches high they are ready to be tested.
Label the plants 1 to 3.
Always water #1 with ½ cup fresh water.
Always water #2 with ½ cup fresh water mixed with 1 teaspoon of vinegar.
Always water #3 with ½ cup fresh water mixed with 2 tablespoons of vinegar.
After a week can you see a difference in how the plants look? How about after two weeks? Write down the effects of the weak acid and strong acid treatments.
This is what acid rain does to plants. It weakens them and in some cases can kill them.
In the United States acid rain is having its worst effect in the northeastern states. Some lakes in the Adirondack Mountains in upstate New York have gotten so acidic that fish and frog populations have begun to disappear. Acid rain even makes buildings and statues begin to corrode over time. Why is acid rain so bad in this area, when it has so few smokestacks of its own? There are three main reasons. One reason is the weather. The main winds in the United States blow from west to east. The second reason is where the pollution is made. Smokestacks in the industrial cities in the Great Lakes region of the United States and Canada belch out a lot of pollutants. The third reason is that to try and decrease local air pollution, the factories made their smokestacks taller. This pushed the pollution higher up in the atmosphere and it blew away in the strong winds. This made the local people much happier. The only problem was that it blew the pollutants right into the northeastern states.
In 1990, the U.S. Congress passed laws as part of the Clean Air Act to lower acid rain pollutants. Over time scientists hope that the decrease in sulfur and carbon emissions from factories will slow acid rain effects in the Northeast.
Water pollution comes in many forms! Break the Vowel Switch Code to learn what one silly kid wants to do about it.
