This week's Topic In Depth focuses on the use of biological organisms to reduce environmental contamination.

From the US Geological Survey, the first site (1) is a general introduction to bioremediation and includes links to several examples of successful bioremediation projects. Next (2) is a glossary of terms related to biological remediation. The third site is an educational resource (3) developed to teach high school students about environmental contamination and the use of plants to remove pollutants. The Bioremediation Discussion Group (4) includes a useful "archive of technical papers on bioremediation." The next two Web sites are specific to the process of phytoremediation, which uses plants to remediate contamination (5) (6 ). The next site (7) gives an example of an application using microbes from chicken compost to reduce air pollution. Lastly, this fact sheet (8) from the Ohio State University Extension Service focuses on bioremediation specific to wastewater treatment.