The article describes a large prospective study that "confirmed a strong association between cigarette smoking and lung cancer but found no link between the disease and secondhand smoke." The study tracked more than 76,000 women, 901 of whom eventually developed lung cancer. Although "the incidence of lung cancer was 13 times higher in current smokers and four times higher in former smokers than in never-smokers," says the JNCI article, there was no statistically significant association between reported exposure to secondhand smoke and subsequent development of lung cancer.
In some ways the findings aren't a big surprise, the link between passive smoking and lung cancer has always been more emotional than scientific. However, the obsession with this single risk factor has meant that lung cancer receives the smallest amount of research spending of any major cancer - just five per cent of total research spending into the 20% plus of cancer deaths that are from lung cancer. The research bodies have chosen instead to direct resources into campaigns for smoking bans, advertising bans, higher duty and now plain packaging.
The problem isn't that people want to reduce deaths that result from smoking but that they do so knowing that what they say is inaccurate, even incorrect:
...the U.S. Centers for Disease Control and Prevention will tell you that "secondhand smoke causes an estimated 3,400 lung cancer deaths among U.S. nonsmokers each year," scientists have long understood that the actual number might be closer to zero.
All those smoking bans - whether you agree with them or not - were introduced on the basis of, at best poorly understood epidemiology and probably with the absolute knowledge that the claims for passive smoking and lung cancer simply weren't true.
It was always about denormalising smoking:
"The strongest reason to avoid passive cigarette smoke is to change societal behavior: to not live in a society where smoking is a norm."
Of course they didn't give that as the reason when they kicked you out from the bar and onto the pavement, did they!