Rose Flores University of Houston – Downtown Biology 1312

What is Acid Deposition? Acid Rain refers to the deposition of acidic components in either wet or dry forms Defined by the pH of the liquid. Less than 7 pH is acidic, more than 7 is basic “Clean” rain has a natural acidity of about 5.2 on the pH scale due to water reacting with carbon dioxide in the air to form carbonic acid

 Where is this happening? Today, acid deposition is present in the northeastern United States, southeastern Canada, and much of Europe including portions of Sweden, Norway, and Germany. In addition, parts of South Asia, South Africa, Sri Lanka, and Southern India are all in danger of being impacted by acid deposition in the future.

Acid rain causes acidification of lakes and streams and contributes to the damage of trees and many sensitive forest soils. Acid rain accelerates the decay of building materials and paints, including irreplaceable buildings, statues, and sculptures that are part of our nation's cultural heritage.  Aquatic Organisms  Forests and Ecosystems  Human Health  Visibility

 Acid rain causes a cascade of effects that harm or kill individual fish, reduce fish population numbers, completely eliminate fish. Both low pH and increased aluminum levels are directly toxic to fish.  Low pH and increased aluminum levels cause chronic stress that may not kill individual fish, but leads to lower body weight and smaller size and makes fish less able to compete for food and habitat.

 The plants and animals living within an ecosystem are highly interdependent. Frogs may tolerate relatively high levels of acidity, but if they eat insects like the mayfly, they may be affected because part of their food supply may disappear.  As lakes and streams become more acidic, the numbers and types of fish and other aquatic plants and animals that live in these waters decrease.

 Pollutants that cause acid rain—sulfur dioxide (SO 2 ) and nitrogen oxides (NO x )—do damage human health.  Based on health concerns, SO 2 and NO x have historically been regulated under the Clean Air Act, including the Acid Rain Program.Acid Rain Program  When fully implemented by the year 2015, the public health benefits of the Acid Rain Program are estimated to be valued at $50 billion annually, due to decreased mortality, hospital admissions, and emergency room visits.

 Pollutants that cause acid rain—sulfur dioxide (SO 2 ) and nitrogen oxides (NO x )—do damage human health.  Emissions contribute to visibility impairment, meaning we cannot see as far or as clearly through the air.  In the western part of the U.S., nitrates and carbon also play roles, but sulfates have been implicated as an important source of visibility impairment

 Clean up smokestacks and exhaust pipes  Use alternative energy sources  Restore a damaged environment  Take action as individuals

The overall goal of the Acid Rain Program is to:  Achieve environmental and public health benefits through the reduction of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ).  The program also encourages energy efficiency and pollution prevention. Sulfur dioxide (SO 2 ) and Nitrogen oxides (NO x )- Main cause of Acid Rain

U.S. Environmental Protection Agency Homes Safe Guide: SFGATE Acid Rain: Abstract and Overview