Environmental Protection Agency , acid rain

Fig. 10-11. The pH scale is a measure of hydrogen ion concentration. The pH of common substances is shown with various values along the scale. The Adirondack Lakes are located in the state of New York and are considered to be receptors of acidic deposition. Source U.S. Environmental Protection Agency, Acid Rain—Research Summary," EPA-600/8-79-028, Cincinnati, 1979.

U.S. Environmental Protection Agency. Acid rain. Available online. URL http //www.epa.gov/acidrain/index.html. Accessed on March 19,2008. 

Atmospheric emissions of sulphur dioxide are either measured or estimated at their source and are thus calculated on a provincial or state basis for both Canada and the United States (Figure 2). While much research and debate continues, computer-based simulation models can use this emission information to provide reasonable estimates of how sulphur dioxide and sulphate (the final oxidized form of sulphur dioxide) are transported, transformed, and deposited via atmospheric air masses to selected regions. Such "source-receptor" models are of varying complexity but all are evaluated on their ability to reproduce the measured pattern of sulphate deposition over a network of acid rain monitoring stations across United States and Canada. In a joint effort of the U.S. Environmental Protection Agency and the Canadian Atmospheric Environment Service, eleven linear-chemistry atmospheric models of sulphur deposition were evaluated using data from 1980. It was found that on an annual basis, all but three models were able to simulate the observed deposition patterns within the uncertainty limits of the observations (22). 

The Environmental Protection Agency s Web site explains how acid rain forms, what it does to the environment, and ways we can all help reduce the presence of acid rain. 

Environmental Effects of Acid Rain. Acid Rain Program, United States Environmental Protection Agency, http //www.epa.gov/airmarkets/acidrain/index.html... 

Go to this home pagefor the Environmental Protection Agency and use acid rain as a keyword in the agency s search engine to find numerous articles on this subject. 

UN Conference on Human Environment/UNEP held in Stockholm under the leadership of Maurice Strong. The conference is rooted in the regional pollution and acid rain problems of northern Europe. The conference leads to establishing many national environmental protection agencies and the United Nations Environment Programme (UNEP), http //www.unep.org/... 

Acid Rain Program. U.S. Environmental Protection Agency. 

United States Environmental Protection Agency (2005). EPA Acid Rain Program 2004 Progress Report, EPA 430-R-05-012. Clean Air Markets Division, U.S. Environmental Protection Agency (www.epa.gov/airmarkets). 

The impact of the emission cuts is beginning to be noticed, although more with respect to deposition than ecosystem recovery. The U.S. Environmental Protection Agency soon reported declines in wet sulphate deposition in the order of 10 to 25% across the eastern United States. There are also possible improvements with respect to dry deposition of sulphates, fine particulate matter concentrations, and visibility. Aquatic and terrestrial ecosystems respond slowly, and it is not surprising that evidence of ecosystem improvements would trail behind trends in reduced atmospheric transport and deposition. The EPA, while modest in its assessment of the environmental benefits to be accrued from reduced acidification, has been rather bullish about the investment in human health benefits represented by acid rain controls. It expects SO emission cuts to reduce American health costs by 10 billion annually, through reduced morbidity and mortality, and these savings are projected to rise to 40 billion annually by 2010 (EPA 1995). 

U.S. Environmental Protection Agency, March 22, 1994, Acid Rain Program Nitrogen Oxides Emission Reduction Program, (59 Federal Register 13539). 

In the US, the Clean Air Act was introduced in 1963 as a federal law to control air pollution. The Environmental Protection Agency is responsible for enforcing the regulations and for protecting the public from airborne contaminants that are hazardorrs to health arising from domestic and industrial sources. There have been subsequent amendments to the Act, particularly to address airborne pollution such as acid rain and effects of ozone depletion. 

Environmental Protection Agency (1986) Acid Rain, OPA-86-009, EPA, Washington DC. 

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