My romantic views of wood smoke hit reality when I first camped in Canada's Banff-Jasper national parks, where you could buy unlimited firewood for the night for $5. Everyone bought it, it seemed. Trying to breathe downwind of a campground was a rude wakeup call. It should definitely be restricted in denser residential areas. I can't imagine some of the towns in Germany or Poland where residents depend on wood fires for heat.