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Acid rain
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1. History of acid rain
In the end of the seventies the problem with acid rain was discovered. There were a lot of extensive forest diebacks and lakes became acid. First observations were made in Sweden where you could see absolute clean lakes. It turned out that these lakes were so clean because there was no life any more. In some lakes the ph-value was already three. This is a normal ph-value of acetic acid. In the following a big hype was produced and the perception of acid or toxic rain was formed. The cause of the acid rain people supposed was the greenhouse effect. But now of course it is detected that acid rain is for example produced by exhaust gases also by air pollution or thunderstorms which will be more explained in the following part.
The effects of acid rain
On lakes
Especially lakes which own little nutriments are swiftly acid resistant. That way in Scandinavia lakes have ph-values of about three. This leads to die off from micro-organisms and plants and finally of the whole ecosystem. If lakes are linked with rivers, which have passed before through an acid forest soil, the ph-value will depreciate supplementary. On the picture you can see what acid rain arranges on animals which live in lakes. In addition fish-eating birds or other animals are also affected.
On buildings
The fact that there is an amount of protons in rain water causes that limestone cancelled materially faster. So for example limestone reacts with sulphuric acid to cement. Because of that the stone crumbles away and in a similar way the sandstone will also be destructed. On account of this scores of cultural monuments will be destroyed.
The picture shows us the changing on statues concerning acid rain.
The sandstone statue from 1702 on the left was taken in 1908 and the right in 1968.
You can see how the stonework has been affected.
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