William D. Ruckelshaus being sworn in as the first-ever administrator of the US Environmental Protection Agency in 1970 with President Richard M. Nixon who appointed him standing at his side. Two years later%2C Ruckelshaus%2C acting on a growing mound of scientific evidence recommended that Nixon ban biocides used to protect livestock. Nixon issued an executive order overturned by Ronald Reagan though the problems raised about the dangers of biocides have only grown. Photo courtesy US EPA