I recently saw an ad taken out, I think by everyone's fsvourite mayor, on the back of a London bus demonising wood burning.
I'm not sure if its still true but the claims made about woodburning stoves being significantly damaging were because of shoddy statistical work.
Air pollution in London is measured as a total. Then they worked out how much was caused by gas heating, by motor vehicles, by buses etc. and then attributed the rest to woodburning stoves without any measurement. The problem being that they used manufacturers' official test data for estimating the emissions of buses, which is completely inapplicable to the way buses are driven - one pedal or other is hard on the floor all the time.
I think they also don't take proper account of the massive emissions of fast food shops and restaurants.