Acid rain is precipitation contaminated with highly acidic particles. It occurs both as a result of natural activity, such as volcanic eruptions, and the collection of man-made particulate matter and emissions in the atmosphere. According to many environmental experts and scientists, severe environmental and even structural damage can be caused by acid rain, leading many to call for updated emission standards that would reduce man-made acid precipitation.
When certain chemical gases such as sulfur dioxide, ammonium, or nitrogen are expelled into the atmosphere, they can combine with water molecules to create acid-heavy clouds. These clouds may be propelled by the wind and atmospheric changes, eventually releasing precipitation in the form of acid rain, snow, sleet, fog, or other types of precipitation. Damage is caused when the acidic nature of this precipitation mixes with whatever it hits, including soil, stone, plants, or water.
Acid rain damage takes many forms and can have many outcomes. Generally, the precipitation causes alteration to the pH balance of whatever it touches, resulting in changes to the chemical makeup. According to studies, these chemical alterations can have devastating effects on all types of ecosystems and may even pose danger to human health and civilization.
Nutrient depletion in soil is one common type of acid rain damage. As the acidic water compounds hit the soil, they can leach out vital nutrients that make soil fertile. Enough contamination can lead to patches of soil becoming unable to support life, cutting off the nutritional feed line to any plants in the affected area. The chemical compounds in the rain disperse in the soil, allowing the accumulation of harmful chemicals, such as aluminum, that can kill plants. From this point on, the destruction accumulates, as the resulting die-off of plants leads to diminished habitat and food sources for resident animal, bird, and insect populations.
Acid rain damage can also be extremely dangerous to water-based ecosystems. As the acidic water falls into a lake or stream, the pH balance drops and harmful chemicals, like aluminum and mercury, are released into the body of water. Many aquatic species are extremely sensitive to acid and cannot hatch eggs or survive in contaminated waters; additionally, increased acid levels may kill aquatic plants and micro-organisms, destroying the main food sources of many aquatic creatures.
In human society, some studies have linked high acid rain damage to cancers and other illnesses. This dangerous precipitation also can be extremely destructive to certain types of stone, such as limestone and marble, and has caused severe damage to many ancient buildings, bridges, monuments, and works of art. Acid rain damage has caused many governments to enact protective and restoration efforts to preserve national monuments, including the Statue of Liberty in New York, and the Parthenon in Athens.