5.2 Detection and Monitoring of Pollution
5.2.1 Describe two direct methods of monitoring pollution.
There are two ways of measuring pollution: direct and indirect.
Direct measurements record the amount of pollutant. Indirect measurements record changes in a biotic or an abiotic factors cause by the pollutants.
Indicator species – Species that are directly affected by the pollution. And Number of pollutants in a system define the size of their population. For example: leafy lichens on trees if the air is unpolluted
5.2.2 Define the term biochemical oxygen demand (BOD) and explain how this indirect method is used to assess pollution levels in water.
The biochemical oxygen demand is a measure of the amount of dissolved oxygen required to break down organic materials. The greater the amount of polluting organic matter, the more microbes are required to break it down. (So, high dissolved oxygen, high levels of pollution)
5.2.3 Describe and explain an indirect method of measuring pollution levels using a biotic index.
Biotic index isa scale 1-10 that gives a measure of the quality of an ecosystem by the presence and abundance of the species living in it . Using this index and indicator species is another indirect method of measuring pollution. The pollutant are not measured directly but their effect on biodiversity is measured. |
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