Tobacco companies obstructed science, history professor says

 https://news.stanford.edu/pr/2007/pr-proctor-021407.html

Proctor has used poll results stretching back to the 1940s to show that in fact some people were ignorant of the risks. "Millions of people in the '60s, '70s and '80s didn't know that tobacco caused lung cancer or heart disease," Proctor said. "An increasing number knew, but not everyone knew. And not everyone knew because the industry was manufacturing doubt, fomenting ignorance. Industry executives created a climate of untruth that people bought into and died from."