Acid deposition is a serious environmental problem that affects many parts of the United States. Acid rain is a combination of airborne acidic particles and precipitation that falls to the earth. Although rain is naturally acidic, air pollution resulting from human activities has increased the acidity of rainfall. Acid deposition can have negative effects on forest, stream, and lake ecosystems, as well as on man-made items. Pennsylvania is the acid rain capital of the country, receiving the most acidic deposition of any place for which records are kept.
In this exercise, students collect soil and water samples and measure the pH of each. Students take samples while learning how to properly and accurately use pH meters. From the data, they draw conclusions about the impact of acid deposition in their area. Other observations include the pH preferences of plant species at the sample site and the possible effects of recent rainfall.