Secondhand smoke health effects
I've actually read the study in question (it's available at
http://www.epa.gov/nceawww1/ets/etsindex.htm
if you want to do so too before you respond to this post). It seems pretty clear-cut to me. The most important message is, if you have children, don't smoke in your home.
This was a study of long-term exposure. Nobody is seriously suggesting that walking past a smoker on the street will do you any serious harm. But if you work in an office with smokers, or if you live with smokers, studies have shown that you inhale almost exactly the same pollutants smokers do, just in smaller quantities.
This is why the adult lung cancer section of the study was so controversial. Because there was already significant evidence of a connection, EPA thought a 90% confidence level was appropriate. In other words, since exactly the same substances are present in the lungs of active and passive smokers, even smaller correlations are likely to be significant.
What's not controversial, and what pro-smoking critics usually ignore, is the rest of the report. EPA reviewed data on children living with parents who smoked. The data, reviewed at a standard 95% confidence rating, was incredibly clear. If you smoke, your children will be more likely to get ear infections, throat infections, pneumonia, and bronchitis. They are more likely to develop chronic athsma. If they already have athsma, their attacks will be more severe and are more likely to be life-threatening. They will cough and wheeze more, and will have diminished lung function. They are more likely to spend time in the hospital than other children. Children of smoking mothers are more likely to die of SIDS, although it's unclear whether this is related to ETS or smoking during pregnancy.
This is a pretty clear signal to anyone who smokes: if you have kids, don't smoke in your home or in your car, and don't allow anyone else to. The numbers are less clear but still suggestive for spouses of people who smoke and for adults who are exposed to secondhand smoke in the workplace. The fact is, this is a difficult area to study, since it's impossible to measure actual exposure, and so scientists must rely on proxies such as how much a spouse or parent smokes, as estimated by a nonsmoker. We can't expect crystal clarity on long-term risks like cancers. But to say that the EPA metaanalysis proves nothing is just plain untrue.
To summarize: secondhand smoke in the home is bad for children, and long-term exposure in the home or workplace seems to be bad for everyone. I'd be glad to hear opposing points of view, but please read the study before you criticize it.
