Some things are hard to believe, like a prediction that Martians will land in Atlanta tomorrow.
Even harder to accept is the fact that some folks, including people in positions of substantial responsibility -- such as mayors, governors and other politicians -- don't believe that exposure to secondhand smoke is harmful.
It is. The evidence is very clear that exposure to secondhand smoke can cause illness and death.
Despite all of that evidence, we still seem to have barriers in place that prevent us from enacting laws that would protect those of us who are non-smokers (and I would also include former smokers) from the harmful effects of environmental tobacco smoke.
One remaining issue regarding the harms of secondhand smoke has been the question of how much lung cancer risk exists for non-smokers who are exposed to secondhand smoke in the workplace.
A study reported today in the American Journal of Public Health answers that question and takes us one step closer to understanding how dangerous secondhand smoke can be.
As the authors point out, most research on the topic of secondhand smoke and the risk of developing lung cancer has been done with the non-smoking spouses of smokers.
Where we don't have a clear picture is the lung cancer risk you face if you are a non-smoker and work in a place that permits smoking. For many folks, that means in restaurants, bars and casinos, among other locations.
To answer this question, the researchers examined a number of scientific papers published on the topic of lung cancer risk and secondhand smoke in the workplace.
They took the information from those papers and pooled the numbers so they could get an idea of whether non-smoking workers in those workplaces faced an increased risk of getting lung cancer.
The answer, simply stated, was "Yes."
When combining all of the papers and all of the subjects studied as part of those 22 reports, the researchers found there was a 24 percent increased risk of developing lung cancer in non-smoking employees who were exposed to secondhand smoke in the workplace.
However, they also noted that if you were a worker considered to be "highly exposed" to environmental tobacco smoke at work, then your risk of getting lung cancer was doubled compared to people who did not smoke.
That may not seem like much. After all, we know that almost all lung cancers are related to cigarette smoking. About 10 percent to 15 percent of lung cancers occur in people who don't smoke.
The chances of any one man getting lung cancer during his lifetime are 1 in 12, and for women, the risk is 1 in 16.
If you are a non-smoker, your odds of getting lung cancer are much less than that.
But, if you work in a smoky bar for a length of time, and you don't smoke yourself, then your chances of getting lung cancer increase significantly, according to this study.
The reason this is such a problem, as pointed out in the article, is that many folks -- even today -- work in smoky places. That means that many folks are at an unnecessary risk of getting lung cancer.
Let's not forget that a diagnosis of lung cancer is no minor issue. Most of the folks with this disease are diagnosed at late stages, and frequently the disease is fatal.