Use of in vivo and in vitro bioassays for environmental monitoring

Bioassays are used in environmental toxicology to examine the effects of man-made contaminants on individual organisms and ecosystems. These tests involve examining the effects of individual chemicals or complex mixtures, such as effluents, on representative biological systems or whole organisms, and are commonly incorporated into environmental monitoring programs. Bioassays can be conducted either in vitro by the use of cell culture techniques in the laboratory or in vivo in either the laboratory or the field. In vitro bioassays are frequently used to assess specific mechanisms of action of the contaminants that are present in an environmental sample, such as receptor-binding properties, whereas in vivo bioassays provide a more integrated organism response. However,there are many endpoints that can be measured using both types of approaches, such as effects on growth, endocrine function, and DNA damage. Both in vivo and in vitro bioassay approaches offer their own advantages and disadvantages, some of which can be addressed using the toxicity identification and evaluation procedure. Future development of a wider range of bioassays that more fully reflect the diversity of organisms in natural systems will contribute to more accurate understanding of the potential effects of environmental contaminants.