Trends in the use of protozoa in the assessment of wastewater treatment

Increasing environmental pollution and the continuous development of new ch emicals and drugs has led to ever growing concern about the potential effec ts of these compounds directly or indirectly on human health. As concerns w ater pollution, protozoa seem to be an excellent tool to assess both toxici ty and pollution: they are regarded as biological indicators of pollution w hen their presence or absence can be related to particular environmental co nditions, and they are considered test organisms when a species or populati on is used to evaluate the toxicity of relevant toxic compounds. Thus, an i ntegrated approach is being developed to assess how toxic compounds affect the different biological levels of organisation - from the community level to the species level - of ciliated protozoa. The present paper reports and discusses the current state of the art of this approach. (C) 2001 Editions scientifiques et medicales Elsevier SAS.