Pollution

More waste is being produced which, unless properly handled, may pollute:
− water – with sewage, fertiliser or toxic chemicals
− air – with smoke and gases such as sulphur dioxide which contribute to acid rain
− land – with toxic chemicals, such as pesticides and herbicides, which may be washed from land into water.
Living organisms can be used as indicators of pollution:
− lichens can be used as air pollution indicators
− invertebrate animals can be used as water pollution indicators.

Humans produce waste. Each family in the UK produces more than 1.5 tonnes of waste each year which ends up in landfill. Industry, including farming, also produces a lot of waste.

We pollute the land, the air and the water with our rubbish and chemicals. (see above)

Pollution Indicators

Different species are more or less sensitive to different chemicals. By surveying what species are present in a certain area we can figure out the degree of air pollution in that area.

Lichens are very sensitive to air pollution such as sulphur dioxide.

This species tolerates oxides of Sulphur	This species tolerates oxides of Nitrogen	Air must be clean for this species to thrive

Many tiny animals called invertebrates live in most freshwater streams. (Invertebrates have no backbone). generally the more species of these animals are present in a certain location then the cleaner the water is. This is called the biotic index. Certain species are also good indicators.

If Stonefly larvae are present then this is a good indicator that the water is clean. If they are not but Mayfly larvae are present then the water is reasonable.

If neither are present then the water is badly polluted.