The USGS has been at the forefront of studying the impacts of acid rain for decades. How does acid rain form? What does it do to the landscape? Can it burn you like battery acid? Keep reading to find out more...
BACKGROUND
Acid rain is the term commonly used by scientists to describe rain that is abnormally acidic. What does that mean? Well, plain distilled water, like that used in laboratories, is neutral (not acidic or basic). Since rain naturally has things dissolved in it, it will always be slightly acidic. However, when rain reacts with certain air pollutants, such as sulfur or nitrogen oxides, the water vapor converts into very diluted forms of sulfuric or nitric acids. The acidity of this rain is on par with that of grapefruit juice, which may not seem like much, but is much more caustic than plain water.
The main sources of pollutants that trigger acid rain are vehicles and industrial and power-generating plants. The areas of greatest acidity are in the northeastern United States. This pattern of high acidity is caused by the large number of cities, the dense population, and the concentration of power and industrial plants in the Northeast. In addition, the prevailing wind direction brings storms and pollution to the Northeast from the Midwest.
IMPACT OF ACID RAIN ON FORESTS
Acid rain can dissolve certain more soluble elements from the soil, like aluminum. The dissolved aluminum begins to accumulate and can reach toxic levels as it enters local streams and wetlands. Acid rain also removes important nutrients from the soil, such as calcium, potassium, and magnesium. The lack of nutrients can negatively affect the health of plants and animals. Lastly, the combination of reduced calcium and excessive aluminum can make forests more susceptible to pests, disease, and injury from freezing and drought, as a proper balance of these nutrients is vital to forest health.

WHAT USGS AND OTHERS DOING ABOUT ACID RAIN?
Scientists from many disciplines study acid rain and its impact. The National Acid Precipitation Assessment Program (NAPAP), a Federal program involving representatives from more than a dozen Federal agencies, has sponsored studies on how acid rain forms and how it affects lakes, crops, forests, and materials. Because buildings and monuments cannot adapt to changes in the environment, as plants and animals can, historic structures may be particularly affected by acid precipitation. Scientists are studying effective control technologies to limit the emissions from power plants and automobiles that cause acid rain. The impact and usefulness of regulations that would require limits on air pollution are also being studied. Finally, scientists are examining the processes of deterioration to find effective ways to protect and repair our historic buildings and monuments. Agencies like the National Park Service, which are charged with protecting and preserving our national heritage, are particularly concerned not only about the impact of acid rain but also about making the best choices for maintaining and preserving our historic buildings and monuments.
RELATED USGS RESEARCH
The USGS investigates the chemistry, source, fate, and transport of airborne pollutants and their affect on the landscape.
- Acid Rain, Atmospheric Deposition and Precipitation Chemistry
- Acid Rain: Do you need to start wearing a rain hat?
- Acid Rain and Our Nation's Capital
ADDITIONAL RESOURCES
National Atmospheric Deposition Program
U.S. Environmental Protection Agency
Examples of research USGS conducts on acid rain.
Acid Rain - The USGS Water Science School
National Atmospheric Deposition Program National Trends Network
The USGS reports on the occurence, magnitude, and impacts of acid rain across the country. Here are a few useful publications that showcase USGS acid rain science.
Volcanic air pollution hazards in Hawaii
Acid rain and its environmental effects: Recent scientific advances
Protecting national parks from air pollution effects: Making sausage from science and policy
Long-term trends in alkalinity in large rivers of the conterminous US in relation to acidification, agriculture, and hydrologic modification
Acid rain in Shenandoah National Park, Virginia
USGS Tracks Acid Rain
The USGS newsroom distributes media alerts, press releases, and technical memos that highlight new and relevant research.
Below are frequently asked questions associated with acid rain.
How does acid precipitation affect marble and limestone buildings?
When sulfurous, sulfuric, and nitric acids in polluted air and rain react with the calcite in marble and limestone, the calcite dissolves. In exposed areas of buildings and statues, we see roughened surfaces, removal of material, and loss of carved details. Stone surface material may be lost all over or only in spots that are more reactive. You might expect that sheltered areas of stone buildings...
- Overview
The USGS has been at the forefront of studying the impacts of acid rain for decades. How does acid rain form? What does it do to the landscape? Can it burn you like battery acid? Keep reading to find out more...
BACKGROUND
Acid rain is the term commonly used by scientists to describe rain that is abnormally acidic. What does that mean? Well, plain distilled water, like that used in laboratories, is neutral (not acidic or basic). Since rain naturally has things dissolved in it, it will always be slightly acidic. However, when rain reacts with certain air pollutants, such as sulfur or nitrogen oxides, the water vapor converts into very diluted forms of sulfuric or nitric acids. The acidity of this rain is on par with that of grapefruit juice, which may not seem like much, but is much more caustic than plain water.
The main sources of pollutants that trigger acid rain are vehicles and industrial and power-generating plants. The areas of greatest acidity are in the northeastern United States. This pattern of high acidity is caused by the large number of cities, the dense population, and the concentration of power and industrial plants in the Northeast. In addition, the prevailing wind direction brings storms and pollution to the Northeast from the Midwest.
Acid rain doesn't look any different then regular rain, however the effect it has on the landscape is considerably different. (Credit: Pixabay. Public domain.) IMPACT OF ACID RAIN ON FORESTS
Acid rain can dissolve certain more soluble elements from the soil, like aluminum. The dissolved aluminum begins to accumulate and can reach toxic levels as it enters local streams and wetlands. Acid rain also removes important nutrients from the soil, such as calcium, potassium, and magnesium. The lack of nutrients can negatively affect the health of plants and animals. Lastly, the combination of reduced calcium and excessive aluminum can make forests more susceptible to pests, disease, and injury from freezing and drought, as a proper balance of these nutrients is vital to forest health.
Sources/Usage: Some content may have restrictions. Visit Media to see details.A forest of dead trees damaged by acid rain (Credit: Pixabay). WHAT USGS AND OTHERS DOING ABOUT ACID RAIN?
Scientists from many disciplines study acid rain and its impact. The National Acid Precipitation Assessment Program (NAPAP), a Federal program involving representatives from more than a dozen Federal agencies, has sponsored studies on how acid rain forms and how it affects lakes, crops, forests, and materials. Because buildings and monuments cannot adapt to changes in the environment, as plants and animals can, historic structures may be particularly affected by acid precipitation. Scientists are studying effective control technologies to limit the emissions from power plants and automobiles that cause acid rain. The impact and usefulness of regulations that would require limits on air pollution are also being studied. Finally, scientists are examining the processes of deterioration to find effective ways to protect and repair our historic buildings and monuments. Agencies like the National Park Service, which are charged with protecting and preserving our national heritage, are particularly concerned not only about the impact of acid rain but also about making the best choices for maintaining and preserving our historic buildings and monuments.
RELATED USGS RESEARCH
The USGS investigates the chemistry, source, fate, and transport of airborne pollutants and their affect on the landscape.
- Acid Rain, Atmospheric Deposition and Precipitation Chemistry
- Acid Rain: Do you need to start wearing a rain hat?
- Acid Rain and Our Nation's Capital
ADDITIONAL RESOURCES
National Atmospheric Deposition Program
U.S. Environmental Protection Agency
- Science
Examples of research USGS conducts on acid rain.
Acid Rain - The USGS Water Science School
The USGS Water Science School is the place for anyone of any age to learn all about water.National Atmospheric Deposition Program National Trends Network
The National Atmospheric Deposition Program (NADP) is a 40-year old organization of federal, state, local, academic, tribal, and private entities who support operation of 5 national monitoring networks. Kentucky and Indiana operate 3 National Trends Network (NTN) sites as part of the National Atmospheric Deposition Program (NADP). Monitoring for NTN is consistent, standardized, high quality... - Multimedia
- Publications
The USGS reports on the occurence, magnitude, and impacts of acid rain across the country. Here are a few useful publications that showcase USGS acid rain science.
Volcanic air pollution hazards in Hawaii
Noxious sulfur dioxide gas and other air pollutants emitted from Kīlauea Volcano on the Island of Hawai‘i react with oxygen, atmospheric moisture, and sunlight to produce volcanic smog (vog) and acid rain. Vog can negatively affect human health and agriculture, and acid rain can contaminate household water supplies by leaching metals from building and plumbing materials in rooftop rainwater-catchmAuthorsTamar Elias, A. Jeff SuttonAcid rain and its environmental effects: Recent scientific advances
The term ‘acid rain’ refers to atmospheric deposition of acidic constituents that impact the earth as rain, snow, particulates, gases, and vapor. Acid rain was first recognized by Ducros (1845) and subsequently described by the English chemist Robert Angus Smith (Smith, 1852) whose pioneering studies linked the sources to industrial emissions and included early observations of deleterious environmAuthorsDouglas A. Burns, Julian Aherne, David A. Gay, Christopher M.B. LehmannProtecting national parks from air pollution effects: Making sausage from science and policy
The story of air pollution research, policy development, and management in national parks is a fascinating blend of cultural change, vision, interdisciplinary and interagency collaboration, and science-policy-management-stakeholder collaborations. Unable to ignore the loss of iconic vistas from regional haze and loss of fish from acid rain in the 1980s, the National Park Service (NPS) embraced anAuthorsJill S. Baron, Tamara Blett, William C. Malm, Ruth Alexander, Holly DoremusLong-term trends in alkalinity in large rivers of the conterminous US in relation to acidification, agriculture, and hydrologic modification
Alkalinity increases in large rivers of the conterminous US are well known, but less is understood about the processes leading to these trends as compared with headwater systems more intensively examined in conjunction with acid deposition studies. Nevertheless, large rivers are important conduits of inorganic carbon and other solutes to coastal areas and may have substantial influence on coastalAuthorsEdward G. Stets, Valerie J. Kelly, Charles G. CrawfordAcid rain in Shenandoah National Park, Virginia
Visitors to Shenandoah National Park (SNP) enjoy the animal and plant life and the scenery but may not realize how vulnerable these features are to various threats, such as invasion of exotic plants and insects, improper use of park resources by humans, and air and water pollution. The National Park Service strives to protect natural resources from such threats to ensure that the resources will beAuthorsKaren C. Rice, Frank A. Deviney, Gordon OlsonUSGS Tracks Acid Rain
The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that inAuthorsJohn D. Gordon, Mark A. Nilles, LeRoy J. Schroder - News
The USGS newsroom distributes media alerts, press releases, and technical memos that highlight new and relevant research.
- FAQ
Below are frequently asked questions associated with acid rain.
How does acid precipitation affect marble and limestone buildings?
When sulfurous, sulfuric, and nitric acids in polluted air and rain react with the calcite in marble and limestone, the calcite dissolves. In exposed areas of buildings and statues, we see roughened surfaces, removal of material, and loss of carved details. Stone surface material may be lost all over or only in spots that are more reactive. You might expect that sheltered areas of stone buildings...