Tell that to Roy Castle, and to my late grandfather, who didn’t smoke but was forced to inhale a load of second-hand smoke.
And on what basis do you feel that it is a myth? Crackpot theories and wishful thinking, or genuinely objective scientific research?
Second-hand smoke does not cause cancer. Says the World Health Organization.
"In epidemiologic research," noted a 1994 press release from the National Cancer Institute, "relative risks of less than 2 are considered small and are usually difficult to interpret. Such increases may be due to chance, statistical bias, or effects of confounding factors that are sometimes not evident." The press release concerned a study reported in the Journal of the National Cancer Institute that found that women who have abortions are 1.5 times as likely to get breast cancer as women who don't. An editorial that accompanied the study said that a 50 percent difference in risk "is small in epidemiologic terms and severely challenges our ability to distinguish if it reflects cause and effect or if it simply reflects bias."* At least seven studies have found a statistically significant link between abortion and breast cancer, and a 1996 meta-analysis yielded a risk ratio of 1.3 In response, public health authorities, reporters, and even the researchers themselves have emphasized the uncertainties associated with small relative risks. Such caution is equally appropriate in discussions of ETS and lung cancer, but it is rarely seen--perhaps because the right to smoke, unlike the right to abortion, is not very fashionable in journalistic and public health circles."--p. 168One of the largest case-controlled studies was led by Ross C. Brownson of the Missouri Department of Health. His focus was on lung cancer since the EPA had, in a politically inspired move, declared environmental tobacco smoke a carcinogen.
"...there was no overall association between lung cancer and childhood, spousal, or workplace exposure, and none of the subgroup results reported in the tables was statistically significant."--page 167, For Your Own Good.*Something overlooked by virtually everyone who likes to trumpet the increase in relative risk for breast cancer as a means of fighting abortion is this: Women with the greatest risk of breast cancer (those who don't have the BRCA mutations) are those who have never been pregnant and have never breast-fed. Women who have the lowest risk of breast cancer are those who have had the most children at the earliest age and breast-fed them for longer periods of time. The idea is that, in addition to any protective effects of breast feeding, the less ovulation cycles one has, the more decreased the risk of breast cancer. Pregnancy decreases the number of ovulation cycles a woman goes through. So a woman who has had an abortion is moved relatively along the continuum toward the nullparous woman in terms of risk for breast cancer because, through the abortion, she has decreased the protective effects of pregnancy and, because she has aborted a child, the protective effects of breast-feeding him.
He's right. It's a myth which has been disproven.