Walter Giger

Walter Giger (born September 6, 1943 in Zürich) is a Swiss chemist. He had been working at the Swiss Federal Institute of Aquatic Science and Technology (Eawag), where he was the head of the division ''Chemische Problemstoffe''. He has been a professor for environmental chemistry at the ETH Zurich since 1995.

Giger is a pioneer who advanced the field of trace organic analysis and its application to significant environmental problems. His research topics include development of analytical techniques for identification of organic pollutants in drinking water, wastewater and natural waters. He investigates their sources, occurrence and fate. In 1984, he discovered that in wastewater treatment plants nonylphenol ethoxylates are transformed to 4-nonylphenols, which are toxic to aquatic life. After several additional studies the use of nonylphenols and nonylphenol ethoxylates was restricted in the European Union in 2003. Provided by Wikipedia