There is evidence, although not conclusive, linking second hand smoking with the development of lung cancer. The risk of lung cancer being approximately 30% higher in nonsmoking spouses of smokers than for nonsmoking spouses of nonsmokers.
After a five-day meeting in Lyons, France, this week, they suggested non-smokers who are exposed to second-hand smoke are between 20% and 30% more likely to develop lung cancer
I also saw a penn & teller episode about second hand smoking that said the same thing, that there was a 50% raise in lung cancer risks. However they also said that the risks were minor, that it was something along the lines of 10 per 100000 vs 15 per 100000, making the difference irrelevant.
So is second hand smoke dangerous, or worth worrying about? i cant find stats on how common lung cancer is among non smokers but i’d assume pretty rare, and a 50% jump could be pretty minor.
Here is an example of how figures regarding health are presented:
A smoker aged under 45 is 15 times more likely to die of heart disease than a non smoker.
The death rates per 100,000 are 104 and 7 respectively.
Presented differently this means that a smoker has 99,896 chances in 100,000 of not dying of heart disease. The nonsmokers chances are 99,993 in 100,000. Dividing 99,896 by 99,993 we find that the smoker has 99.9% of the chance of a nonsmoker of not dying from heart disease.
The use of research involving spouses of smokers is notoriously unreliable in that it does not take in to account the fact that all other lifestyle are shared as well - diet, exercise, drinking sex life …whatever.
Here is a bluntly titled thread **Have we been lied to about secondhand smoke? **
I presume that this is per year? Because heart disease is a lot more common than .1% of all deaths. Or were those invented numbers, just to illustrate the concept?
Are you wondering whether it’s dangerous overall, or just whether it’s a significant cause of lung cancer? Secondhand smoke can aggravate other health issues, such as asthma.
In addition, there is a correlation between exposure to cigarette smoke and cervical cancer:
“The health risks caused by cigarette smoking are not limited to smokers—exposure to secondhand smoke, or environmental tobacco smoke (ETS), significantly increases a nonsmoker’s risk of developing lung cancer (1, 2). (Secondhand smoke is a combination of the smoke that is released from the end of a burning cigarette and the smoke exhaled from the lungs of smokers.) According to the Centers for Disease Control and Prevention (CDC), exposure to secondhand smoke causes about 3,000 lung cancer deaths among nonsmokers and is responsible for lower respiratory tract infections in an estimated 300,000 children each year (3). The U.S. Environmental Protection Agency (EPA) released a risk assessment report in December 1992 that classified secondhand smoke as a Group A (known human) carcinogen—a category reserved for only the most dangerous cancer-causing agents (4, 5). “
From the EPA, “Respiratory Health Effects of Smoking: Lung Cancer and Other Disorders” (large .pdf file):
You are correct these are annual death rates. When I first started using this example some years ago the figures were just as I stated. I do lots of work with numbers and statistics and love to keep track of clever misrepresentative presentations of data. The health industry and advertising are the most fertile sources.