In 1961, Lee went on to obtain a doctorate from the Tokyo University of Agriculture with a dissertation on the leaching and migration of the pesticide Endrin, after which Endrin was banned by the US Food and Drug Administration.
1961 年更以「安特靈農藥的滲透移行性」研究，獲得東京農業大學農學博士學位。後來，美國「食品暨藥物管理局」宣佈禁用安特靈農藥。