Do the American home building standards not take account of this?
Fairly certain it's already law for a while in other places, e.g. if you have a gas stove or central heating then you need greater ventilation and maybe carbon monoxide alarms and so forth.
New houses in some places aren't allowed to have gas connections at all, which is partly greenhouse gas related, but the health benefits and cost savings are part of the discussion. No new home today should be built around the assumption that gas is a sensible fuel source.