Acid rain is rain that contains nitric and sulfuric acid. Snow and fog can also contain nitric and sulfuric acid, and the dangerous effects are the same whether the acid is falling to the earth by rain or snow, or dancing in the air via fog. Any precipitation or dust particle that contains abnormal levels of sulfur dioxide and nitrogen oxides is considered acid rain. Acid rain primarily affects the United States, Europe, and China.
Acid rain directly affects the chemical and pH balances in ground water. The excess aluminum created by acid rain makes aquatic environments such as the sea, lakes, and streams, toxic. The animals that can withstand the imbalance of the water's natural minerals might survive, but quickly lose their food source as the weaker creatures die off. Animals that cannot withstand the chemical imbalances die, fail to reproduce, become deformed due to bone decalcification, or fail to grow normally. Algae growth is increased by acid rain, and rock scaling microbial and invertebrate herbivores lose habitation and die.
Acid rain leaches calcium out of the soil when it is absorbed by the earth. This directly affects the mineral levels of the soil and the creatures, such as snails, that rely on that calcium for shell growth. Consequently, snails die off and birds, which eat them for calcium, lay eggs with shells that are weak and brittle and therefore fail to hatch. Decreased calcium also creates excess aluminum in the soil, preventing trees and other plant life from absorbing water. Weakened plant life cannot tolerate extreme temperatures or fight off insects and disease.
Those seeking an expensive paint job on their car might want to think twice in areas directly affected by acid rain. The excess sulfur dioxide and nitrogen oxides in acid rain damages automobile paint and corrodes surfaces. It is believed that the acid rain causes the damage as it dries on, and evaporates from, the surface. Auto and paint coating manufacturers are trying to develop protective coatings that prevent acid rain corrosion.
Acid rain directly impacts forest ecosystems and their inhabitants. The damage to the forest trees and plants is widespread. Acid rain damages leaves as it falls. Acid rain runoff from the trees and forest floors infiltrates the forest's water supplies; runoff that doesn't enter the water supply is absorbed by the soil. The consequence of this is just as it is for any soil or water source infected with acid rain: the plants and creatures die off, and the creatures that rely on those plants and smaller creatures lose their food source and die, as well.
Plants and animals aren't the only victims of acid rain. Acid rain is dangerous to humans. The same sulphate and nitrate particles that directly affect the soil and water pH balances can cause serious damage to the respiratory system if inhaled deeply. A damaged respiratory system means decreased oxygen in the blood supply, which eventually damages the heart. Studies show an increase of chronic conditions, such as asthma and bronchitis, in people who are regularly exposed to acid rain.
Preventing acid rain is the only way to stop its deadly impact on the environment. Acid rain is caused by pollution. It is released into the air naturally during a volcanic eruption, but the primary cause of excess nitric and sulfuric acid in the environment is manmade. Conserving energy is the number one way humans can prevent acid rain. Using less energy at home decreases the need for power plants. People also need to get out of their car. Using public transportation, biking or walking to destinations leaves fewer cars on the road, less emissions in the air, and a decreased dependency upon fossil fuels. Finally, manufacturing plants can reduce the emissions that cause acid rain by using scrubbers to clean and remove the dangerous chemicals from the pipes before they are released into the air.
National Geographic - National Geographic reports on the causes of acid rain.
SUNY at Plattsburgh - Dr. Tom Wolosz presents a comprehensive report on the effects of acid rain.
Elmhurst College - Virtual chemistry book on acid rain effects and solutions.
Young People's Trust for the Environment - A kid-friendly look at acid rain, what causes it, and how to prevent it.
Upper Midwest Aerospace Consortium - A discussion on the environmental effects of acid rain.
Environmental Protection Agency - Advice on how to reduce the production of acid rain.
United States Geological Survey - The USGS' Water Science for Schools page on acid rain.
The Encyclopedia of Earth - Dr. Gene E. Likens' presents a detailed report on acid rain.
Washington University - An outline of the chemical composition of acid rain.
National Atmospheric Deposition Program - A discussion of the causes and effects of acid rain.
NASA - Scientists hunt for acid rain and methane in wetlands.
National Park Service - Air quality monitoring in the Great Smoky Mountains.
New York State - Department of Environmental Conservation's Q & A on acid rain.
Congress of the United States - Congressional Budget Office's 2008 Policy Options for Reducing CO2 Emissions
Hofstra University: Dr. Jean-Paul Rodrigue and Dr. Claude Comtois' report on the environmental impacts of transportation.
Princeton University - Environmental effects of particulate matter.
Columbia University - Dr. Stephen H. Schneider's paper: The Greenhouse Effect: Science and Policy.
The Environmental Literacy Council - A discussion on acid precipitation and links to helpful resources.
Environment Canada - Frequently asked questions about acid rain.
Department of Health and Human Services Office on Women's Health - A fact sheet on the environment and how it impacts women's health.
National Oceanic and Atmospheric Administration - The 2005 National Acid Precipitation Assessment Program Report presented to Congress.
Hubbard Brook Research Foundation - Links to reports and fact sheets on acid rain.
Cornell University - Atmospheric Dust and Acid Rain, a presentation by Lars O. Hedin and Gene E. Likens.
Purdue University - Sulfur Dioxide Control Technologies, a report by Brian H. Bowen and Marty W. Irwin.
The National Academies Press - A report on programs to control air pollution and acid rain in China.