Hirayama, passive smoking and lung cancer: 30 years on and the numbers still don't lie

Early 2011 represents the 30th anniversary of a groundbreaking publication on the effects of passive smoking and its relationship with lung cancer. In the modern age it is difficult to remember what things were like thirty years ago, at a time when tobacco use was very common and one could freely light up in restaurants, bars and workplaces – pretty much wherever they wanted. Non-smokers in the vicinity had no choice but to inhale second hand smoke. And there was a lot of it. Depending on the country and demographic, between one-third and one-half of all people used tobacco, including many in the health care professions. Nonetheless, the tide was about to turn as the evidence against passive smoking steadily mounted. Indeed, the possibility that tobacco might harm non-smokers had actually been considered within the scientific community for some time. By the late 1970s for example, Enstrom had commented on a large relative increase in lung cancer cases among non-smokers in the United States that was observed between 1914 and 1968.