There may be many unpleasant local smells in Peru — diesel fumes, raw sewage, and dead chickens come to mind as a few — but generally, cigarette smoke isn't one of them. In my time in Peru so far, I've been pleasantly surprised to learn that most locals smoke infrequently, or not at all. I've only really suffered from passive smoking around here, while around other gringos, almost all of whom smoke non-stop. But apart from the fellow tourists, Peru seems to be a very friendly country for non-smokers such as myself.
I really am amazed that Peruanos don't smoke more than they do. I heard that in South-East Asia, for example, smoking is rampant among everyone. Cigarettes aren't that expensive here: but I guess they're expensive enough to be considered a luxury. The result is paradise: no people smoking outside buildings; no people smoking in front of you on the sidewalks; and no people smoking on buses or at bus stops. Less passive smoking than back home in Australia, really. Which is ironic, of course, because there are almost no anti-smoking laws around here.
Like I said, all you have to watch out for is gringos. They smoke in the hostels. They smoke in the bars and discos. They smoke when you share a taxi with them. They smoke everywhere, all the time. The worst are the French, the Germans, the Swedish, and the Israelis; but the English, the Irish, the Yanks, and my fellow Aussies are all bad as well (plus many others). So if you don't like smoke, then Peru's great — except for everyone else back home, who's come here to $#!& it up.