The Effects Of Acid Rain.
Acid Rain refers to all types of precipitation (rain, snow, sleet, hail, fog) that is acidic in nature. Acidic means that these forms of water have a pH lower than the 5.6 average of rainwater. Acid rain kills aquatic life, trees, crops and other vegetation, damages buildings and monuments, corrodes copper and lead piping, reduces soil fertility and can cause toxic metals to leach into underground drinking water sources.
Natural precipitation is not pH neutral (pH 7) in nature. It is more acidic than this, about pH 5.6. This is due to the presence of Carbon Dioxide in the atmosphere. Carbon Dioxide dissolves in water forming Carbonic Acid, lowering the pH of precipitation.
The actual term "acid rain" was first used over one hundred years ago by British chemist Robert Angus Smith. At that time, he realised that smoke and fumes from human activities could change the acidity of precipitation. Despite this awareness, acid rain was not considered an environmental concern until the 1950's. Around this time, increased levels of acidity were discovered in lakes in both Canada and Scandinavia. At first, this was looked at as simply an interesting situation, rather than a problem. Since that time, much research has gone into identifying the sources of acid rain and the damage that it causes. As research continued, the situation reached crisis proportions in the late 1970's.
The author has sought permission from the authors of the pictures used on this site, but in some cases this has not been possible. If the images belong to you please email me at cha02jrb@shef.ac.uk to update the source.