Acid rain, and its negative impacts, have been an important topic in environmental science for many years. The U.S. Environmental Protection Agency (EPA) has defined acid rain as a term that refers to a mixture of dry and wet material containing higher than normal amounts of sulfuric and nitric acids that deposits out of the atmosphere. A combination of natural events, such as volcanic activity and decaying vegetation, and man-made phenomena, such as the combustion of fossil fuels, contributes to the formation of acid rain by emitting gases such as sulfur dioxide (SO2) and oxides of nitrogen (NOx). These gases react with atmospheric water, oxygen, and other gaseous substances, which eventually produces sulfuric and nitric acid. The impact of acid rain can be widespread, sometimes stretching over a hundred miles from the source of the emitted gases.
Over time, statues made of marble will suffer ill effects from exposure to acid rain.
The objectives in this investigation are (1) to demonstrate and measure the effect of acid rain on exposed stone surfaces, and (2) to calculate the rate of acid degradation of limestone.