Acid Rain and Inspectors: Buildings at Risk
It is fair to say that any industrialized region with power plants that burn fossil fuels will show some wear on its surrounding structures from acid rain. But buildings in arid regions are at greater risk because of dry deposition, in which acidic pollutants are present in gases, smoke and dust, which tend to stick to buildings, cars and other structures. When it rains or snows, the subsequent wet deposition of nitric and sulfuric acids becomes even more acidic, which then washes into the soil and aquifers.
Not all buildings or structures suffer the effects of acid rain. How big of a threat it is can be determined by the chemical makeup and interactions of a building's materials. Limestone and marble, which, historically, were used widely because of their availability and workability by artisans, are especially susceptible because they are composed of calcite, or calcium carbonate, which acidic chemicals can dissolve easily. To observe this first-hand, drop a piece of blackboard chalk into a glass of vinegar. Drop another piece of chalk into a glass of water. The next morning, you’ll see the alarming difference.
Modern buildings tend to use granite, which is composed of silicate minerals, such as quartz and feldspar. Silicate minerals resist acidic attacks from the atmosphere. Sandstone, another silica material, is also resistant. Stainless steel and aluminum tend to hold up better. But all minerals, including those found in paint and road overlay, are affected, to some degree.