Effects of Acid Deposition

Acidification of surface waters (lakes, rivers, etc.) and subsequent damage to aquatic ecosystems 

FIGURE 20.10 Measurements of average precipitation pH in the United States during 2004 (data from National Deposition Program 2005). 

FIGURE 20.11 Historical trends in precipitation acidity in eastern North America and northern 

Lake Acidification Lakes acidify when they lose alkalinity (Roth et al. 1985). The total alkalinity or acid-neutralizing capacity is the reservoir of bases in solution. The acidneutralizing capacity of a lake buffers it against large changes in pH. In natural clean waters, most of the acid-neutralizing capacity consists of bicarbonate ion, HCOJ. Carbonate alkalinity is defined by 

When strong acids such as sulfuric acid enter bicarbonate waters, the additional acidity can be neutralized by reacting with the bicarbonate. In other terms, addition of acidity can be balanced by a shifting of the equilibrium, 

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One of the major effects of acidic deposition is felt by aquatic ecosystems in mountainous terrain, where considerable precipitation occurs due to orographic lifting. The maximum effect is felt where there is little buffering of the acid by soil or rock structures and where steep lakeshore slopes allow little time for precipitation to remain on the ground surface before entering the lake. Maximum fish kills occur in the early spring due to the "acid shock" of the first meltwater, which releases the pollution accumulated in the winter snowpack. This first melt may be 5-10 times more acidic than rainfall. 

Controlling the effects of acid deposition by the use oflime or other acid-neutralizing compounds has been tried, but mainly on an experimental basis. Adding lime to lakes usually has only a short-term effect in terms of neutralizing lake acidity. The longevity of the effect is directly related to lake s... 

Cronan, C. S. (1984). Biogeochemical responses of forest canopies to acid precipitation. In "Direct and Indirect Effects of Acidic Deposition on Vegetation" (R. A. Linthurst, ed.), pp. 65-79. Butterworth, Boston, MA. 

Jeffries, D. S., Lam, D. C. L. (1993). Assessment of the effect of acidic deposition on Canadian lakes determination of critical loads for sulfate deposition. Water Science Technology, 28, 183-187. 

Kozlov, M. Ya., Towprayoon, S., Sirikarnjanawing S. (1997). Application of critical load methodology for assessment of the effects of acidic deposition in Northern Thailand. In Proceedings of International Workshop on Monitoring and Prediction of Acid Rain, Seoul, 29.09-1.10.1997, pp. 141-146. 

Steingruber SM, Colombo L (2010) Effect of acid deposition on chemistry and biology of high Alpine lakes. In Bundi U (ed.) Alpine Waters. Handbook of Environmental Chemistry, vol. 6. Springer, Heidelberg... 

Effect of Acid Deposition on Chemistry and Biology of High-Altitude Alpine Lakes... 

Part 1, Alpine Water Resources, examines the hydrological basics, the impacts of climate change in the Swiss Alps, and human interventions in mountain waters. Part 11, Biogeochemistry and Pollution of Alpine Waters, deals with the chemistry of mountain rivers, the effects of acid deposition on high elevation lakes, the glaciers as archives of atmospheric deposition, and the occurrence of persistent organic contaminants. 

The environmental effects of acid deposition that have been most thoroughly studied are probably those on lakes, ponds, and other bodies of fresh water. When acid and oxides of sulfur and nitrogen are added to such bodies of water, the pH of the lake or pond tends... 

The effect of acid deposition on forests remains a topic of some dispute among experts. While there is little doubt that sulfur dioxide and other forms of acid deposition do cause damage to trees, a number of other factors may also be responsible for the widespread die-off of trees observed in forests in Europe and North America over the past 50 years. For example, other elements of polluted air, such as ozone or heavy metals, may also contribute to at least some extent to these disasters. 

Some of the most dramatic environmental effects of acid deposition have involved buildings, statues, monuments, and other structures made of metal and stone. The explanation of this kind of damage is obvious Acids in acid deposition react with metals and with many of the compounds of which rock and other building material are made. For example, corrosion occurs when metals such as iron are exposed to hydrogen ions in the presence of oxygen ... 

Acid rain primarily affects sensitive bodies of water, that is, those that rest atop soil with a limited ability to neutralize acidic compounds (called buffering capacity ). Many lakes and streams examined in a National Surface Water Survey (NSWS) suffer from chronic acidity, a condition m which water lias a constant low (acidic) pH level. The survey investigated tlie effects of acidic deposition in over 1,000 lakes larger than 10 acres and in thousands of miles of streams believed to be sensitive to acidification. Of the lakes and streams surveyed in the NSWS, arid rain has been determined to cause acidity in 75 percent of the acidic lakes and about 50 percent of tlie acidic streams. Several regions in the U.S. were identified as containing many of the surface waters sensitive to acidification. They include, but are not limited to, the Adirondacks. the mid-Appalachian highlands, the upper Midwest, and the high elevation West. 

Raab D, Stumm W. 1993. Effect of acid deposition on the displacement of Al(III) in soils. Water Air Soil Pollut 68 199-212. 

The Cooperative program for monitoring and evaluation of long-range transmission of air pollutants in Europe (EMEP) was launched in 1977 as a response to the growing concern over the environmental effects of acid deposition. EMEP was organized under the auspices of the United... 

National Acid Precipitation Assessment Program. Interim Assessment. The Causes and Effects of Acidic Deposition. Vols. 

Balik, C.M. Fornes, R.E. Gilbert, R.D. Williams, R.S. The Micro-Macro Effects of Acid Deposition on Painted Wood Substrates, draft report to U.S. Environmental Protection Agency, 1989. 

The Causes and Effects of Acidic Deposition. National Acid Precipitation Assessment Program, Interim Assessment, Vol. I, U.S. Gov t Printing Office Washington, DC, Sept. 1987. 

Effects of Acidic Deposition on Forest Ecosystems in the Northeastern United States An Evaluation of Current Evidence, R.L. Burgess, ed. ESF-84-016, State University of New York, College of Environmental Science and Forestry, Syracuse, NY, January 1984. 

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