I have just seen the episode of Penn & Teller's B.S. where they rail against a guy in New York fighting for smoking bans. I'm not in total agreement with them, and they aired smokers using fallacies to argue against the bans, which seems foolish, but I know where they're coming from. For this thread however, I don't care about the bans or the reasoning behind them. What I want to know is,
What the crunk is the truth about secondhand smoke?
I've heard all my life that secondhand smoke is bad for your health. Now, I'm not so attached to that belief that I didn't doubt it immediately while watching the episode. So what I understand is that the EPA did a very questionable study that concluded secondhand smoke caused lung cancer. And that major anti-smoking or cancer-related organizations cite that study to support their claim that secondhand smoke is dangerous. But is that the bottom line?
I mean obviously, absence of evidence is not evidence of absence, but is there really no other credible study that concludes secondhand smoke is dangerous? If not, then why would tobacco companies allow the government of Ontario to print labels on their packages extolling the effects of secondhand smoke? If there's no strong evidence, then wouldn't they fight that all the way?
Now, looking at the anti-smoking essays, I do see some curious side-stepping, such as in this factsheet where the actual statement about secondhand smoke being dangerous is in a little block that's unsourced.
But what about the Paediatrician-in-Chief at Toronto's Hospital for Sick Children
This Ontario Medical Association position paper does cite the EPA study, and also one from 1964(!), but also has a number of others such as
What the crunk is the truth about secondhand smoke?
I've heard all my life that secondhand smoke is bad for your health. Now, I'm not so attached to that belief that I didn't doubt it immediately while watching the episode. So what I understand is that the EPA did a very questionable study that concluded secondhand smoke caused lung cancer. And that major anti-smoking or cancer-related organizations cite that study to support their claim that secondhand smoke is dangerous. But is that the bottom line?
I mean obviously, absence of evidence is not evidence of absence, but is there really no other credible study that concludes secondhand smoke is dangerous? If not, then why would tobacco companies allow the government of Ontario to print labels on their packages extolling the effects of secondhand smoke? If there's no strong evidence, then wouldn't they fight that all the way?
Now, looking at the anti-smoking essays, I do see some curious side-stepping, such as in this factsheet where the actual statement about secondhand smoke being dangerous is in a little block that's unsourced.
Emphasis mine. And I do remember Penn explaining how they came up with the 25% figure, and how they estimate how many die of lung cancer from exposure....an estimated 3,500 men and 2,900 women died from the disease.
* Source: Canadian Cancer Statistics 2004
* A non-smoker exposed to second-hand smoke has a 25% increased chance of lung cancer. Increased chances of cancer of the sinuses, brain, breast, uterine, cervix, thyroid, as well as leukemia and lymphoma are also noted. Health Canada estimates that more than 300 non-smokers die from lung cancer each year because of exposure to second-hand smoke.
* Several studies and significant medical experience show that those who chew tobacco have an increased risk of cancer of the oral cavity. Snuff increases the risk of cancer of the oral cavity and larynx.
* Smoking is also a contributory factor for the development of cancer of the throat, mouth, bladder, kidney, cervix and pancreas.
The encouraging news
* Tobacco use is the single most important preventable cause of death in the world...
But what about the Paediatrician-in-Chief at Toronto's Hospital for Sick Children
Yes? No?We know that second-hand smoke contributes to disease and death in childhood and later life:
*
When a pregnant woman breathes second-hand smoke, the growing fetus is also exposed to nicotine and carbon monoxide. This decreases blood flow, deprives the baby of oxygen, and can lead to low birth weight. Nicotine also reaches the fetus and affects the heart, blood vessels, digestive system, and central nervous system.
*
Several recent studies have shown that children whose mothers were exposed to second-hand smoke during pregnancy have poorer attention, cognition, and behaviour.
*
Babies whose mothers smoke before or after birth may also be more likely to develop colic during the first six months of life.
*
Second-hand smoke is a risk factor for Sudden Infant Death Syndrome (SIDS). Babies are more likely to die of SIDS if any person in the home smokes.
*
Children who are exposed to second-hand smoke are more likely to develop asthma, ear infections, and lung infections such as bronchitis and pneumonia. Children with asthma make more emergency room visits if there is second-hand smoke in their home.
*
The effects of second-hand smoke continue into later life — new evidence suggests that adults who were exposed to it as children are at higher risk for heart disease and some forms of cancer.
This Ontario Medical Association position paper does cite the EPA study, and also one from 1964(!), but also has a number of others such as
Is this all misdirection? The WHO apparently found "weak" evidence for connecting secondhand smoke and cancer. Penn says the risk is "not statistically significant". Are we talking the kind of odds such that it is possible to die in a plane crash, but statistically unlikely... to the point of statistical insignificance? Or more likely than that? Less?1. Glantz SA, Parmley WW. Passive smoking and heart disease: Epidemiology, physiology, and biochemistry. Circulation , 1991:83;1-12.
5. National Research Council. Environmental tobacco smoke: Measuring Exposure and Assessing Health Effects. Washington, D.C., National Academy Press, 1986.