On Jun. 14, 1972, an end to the continued domestic usage of the pesticide DDT was decreed when William D. Ruckelshaus, the first Administrator of the Environmental Protection Agency (EPA), issued an order cancelling nearly all remaining Federal registrations of DDT products. Public health, quarantine, and a few minor crop uses were excepted, as well as export of the material.

The EPA issued a cancellation order for DDT based on its adverse environmental effects, such as those to wildlife, as well as its potential human health risks. Since then, studies have continued, and a relationship between DDT exposure and reproductive effects in humans is suspected, based on studies in animals. In addition, some animals exposed to DDT in studies developed liver tumors. As a result, today, DDT is classified as a probable human carcinogen by U.S. and international authorities.

Ruckelshaus, an Indiana native, moved his family to Seattle in 1975 where he accepted a position as Senior Vice President of Legal Affairs of the Weyerhaeuser Company.