That is not at all what that article says. From your link: “Passive smoking has many downstream health effects—asthma, upper respiratory infections, other pulm

That is not at all what that article says. From your link: “Passive smoking has many downstream health effects—asthma, upper respiratory infections, other pulmonary diseases, cardiovascular disease—but only borderline increased risk of lung cancer,” said Patel. ...So does secondhand smoke cause lung cancer or not? “We can’t say it’s not a risk factor,” said Wang. ...“It’s hard to say anything conclusive with such small numbers,” said Wakelee. ...Moreover, of the nearly 40,000 nonsmokers in the WHI-OS, only about 4,000 reported no exposure to cigarette smoke. “That means almost everybody had passive-smoking exposure,” said Wakelee, “so it’s very hard to say that that exposure is causing the problem—it’s hard to tease out a difference. “We don’t want people to conclude that passive smoking has no effect on lung cancer,” she said. “We think the message is, this analysis doesn’t tell us what the risk is, or even if there is a risk.”