[bregma]

I dunno. I have an airtight stove as the only source of heat. We don't have gas or oil available out in the remote parts of Canada so wood heat is much healthier than freezing to death. Cutting, splitting, and hauling the wood keeps me in remarkably good health and the design of an airtight stove and functional lined chimney stack means I don't breathe smoke or particular matter and efficiency is remarkably high.

The wood used is not fed with industrial fertilizer, it doesn't require clearing the land to grow, and it doesn't require irrigation or ongoing maintenance. 100% of the carbon it contains was sucked out of the air not mined from the foundations of the Earth. It is completely carbon neutral.

I would go as far as saying wood heat is fantastic for human health.