The elimination of emission sources

The most efficient method for reducing the amounts of emissions is obviously by eliminating their source. This may be achieved by changing the technology, raw materials, fuels or simply by changing the products produced, or in the limit, stopping the production processes leading to the exhalations. 

The change of raw material or fuel can be an important method for eliminating an emission source. For example, it is advantageous to use 

A typical example of replacing the products is the fairly recent production of bioinsecticides instead of the production of chemical insecticides. In agriculture, the replacement of powdered fertilizers (causing many problems during their application into the soil) by liquid fertilizers is also important. 

In connection with the problem of the destruction of the ozone layer (discussed in Section 5.2.4.3) it is of enormous importance to stop completely the further production of aerosol sprays using freon as the spraying agent and to replace it with a non-polluting agent. 

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