He testified before the United States Congress three times on behalf of tobacco industry in the 1960s and 1970s, attempting to discredit the fact that smoking causes illness.
[1] From 1964–1971 he was a research pharmacologist at a veterans' hospital in North Hills, Los Angeles; from 1969–1971 he was a pharmacological consultant for the California Department of Public Health.
[4] Okun testified before Congress on behalf of the tobacco industry in 1969,[1] 1972, and 1976[4] saying, in part, that he could not find "persuasive evidence that cigarette smoking causes lung cancer".
[5] From 1973–1976, Okun was one of four physicians in California responsible for nearly all pharmaceutical testing on prisoners in the state, along with J. Alfred Rider, William L. Epstein, and Howard Maibach.
[8] Some of Okun's most-cited publications include: In 1973, he was the president of the American Academy of Clinical Toxicology;[4] he was elected as a fellow to the society in 1976.