In addition to ASH's claim (that 30 minutes of secondhand smoke exposure increases the risk of a fatal heart attack among nonsmokers to that of smokers) being problematic because it is scientifically invalid, I think it is also problematic because it may do damage to smoking education efforts. Here's why:
If smokers actually believe ASH and think that their own risk of a heart attack is as low as that of a nonsmoker exposed to secondhand smoke for 30 minutes, then they may very well completely dismiss the idea that they are at any substantially increased risk of a heart attack. Their perception of their own risk of fatal heart disease due to smoking will likely become grossly underestimated.
After all, it is not irrational for a smoker to believe, as I do, that the risk of a nonsmoker having a fatal heart attack after 30 minutes of secondhand smoke exposure to be miniscule. Therefore, by inference, ASH could easily be perceived as implying that the risk of a fatal heart attack among smokers is miniscule.
This could be quite damaging to anti-smoking education efforts, because it may well undermine efforts to try to convince smokers of the serious health hazards associated with tobacco use.
Heart disease is, in fact, probably the most important health concern associated with smoking (it is by far the most prevalent chronic disease and the leading cause of death) and therefore, in many ways, smokers' perceptions of their own risk for heart attacks may drive their overall perception of risk from smoking.
So not only is the message that is being sent to the public wrong, but it is actually one that could well undermine efforts to impress upon smokers the serious consequences of tobacco use in terms of their own risk for dying from a heart attack.