Environmental Management & Pollution SECONDARY ATMOSPHERIC POLLUTION

4.2 Acid Deposition Acid rain was first identified in the 19th century, when English pharmacist Robert Angus Smith measured high acidity levels in rain falling over industrial regions of England and much lower levels in less-polluted areas near the coast. However, this pattern did not receive sustained attention until biologists began to notice sharp declines in fish populations in lakes in Norway, the northeastern United States, and Canada in the 1950s and 1960s. In each case researchers found that acid precipitation was altering lake chemistry. These findings spurred research into the causes of acid rain.