Dual filter

In the early 1960s, Philip Morris' (PM) Tareyton cigarettes sported a "dual filter" that contained carbon particles. There were subsequent reports that smokers of these "dual filter" cigarettes were experiencing a higher incidence of chronic coughing. Philip Morris CEO Hugh Cullman asked PM's Director of Research, Dr. Helmut Wakeham, to design a test to see if any of the carbon particles were being sucked out of the cigarettes and inhaled. A handwritten note on the original memo from Cullman stated, "... Virginia Johnson said she did this four years ago and carbon particles were sucked out of the cigarettes when smoked. She is looking for the negatives showing the carbon particles of transmitted carbon. RHB 1/10/62"

In another memo, Wakeham responds by minimizing the problem, saying "All cigarette filters can be shown to transmit particles...Medical and industrial hygiene literature abounds in studies of the abilities of humans to inhale copious quantities of solid particles of all kinds without suffering ill effects ... " He concludes by saying,

"Let's worry about the chemical constituents of smoke. There's a real problem!"