[mhax]

I wonder if these stats hold up when looking at modern stoves (which have burning efficiencies upwards of 70%). Bundling open fires, which are highly inefficient along with these stoves seems a little unreasonable. Lots of modern stoves, in the UK at least, come with defra ( http://smokecontrol.defra.gov.uk/) exemption, meaning they can be used in smoke controlled (i.e. built up urban) areas. These controls are more to do with air pollution, rather than direct human harm, but the two measures must be somewhat correlated.