A REVIEW OF CENTRAL EUROPEAN METHODS FOR THE BIOLOGICAL ESTIMATION OF WATER POLLUTION LEVELS.

With the increasing amount and variety of pollution of surface and other waters in the modern world, there is an increasing need for simple, rapid and reliable methods for assessing the degree of purity or contamination of water. Partly for historical reasons, chemical methods have been used more widely than biological ones, although the latter possess certain advantages not shared by the former.Much important work on the biological assessment of water pollution has been done in Central Europe, and the author of this paper reviews the more significant of the modern methods evolved there. Some are ecological, some physiological; and certain of them merit consideration as standardizable procedures, applicable over a wider range of waters than those for which they were developed. To this end it will be necessary to conduct carefully controlled field trials under varying climatic and other conditions.