I'm an ex-smoker so have no agenda to push, but the above report is not medically sound.
1) Smoking might do a whole lot of nasty things to your body, but one thing it doesn't do is affect blood pressure.
2) A survey based on a drop from 7 to 3, is no kind of survey at all, especially when the biggest cause of heart attacks in the US (and UK) is diet (or lack thereof).
3) Smoking can contribute to heart disease over time, but accidently sniffing someone's second-hand Marlboro will not give you a heart attack. A six month public space ban would make no difference to anyone (medically, that is).
Beware of the banners. They're not doing it to help your health, they're doing it beacuse they don't like you enjoying it. And what you like, may well be next.