Burning unseasoned wood?

Wet or unseasoned wood makes more smoke. More smoke equals more particulate matter. In other words, more pollution. Domestic wood and coal fires account for over 39% of PM pollution in the UK.

"Particulate matter emitted from the burning of domestic fuels such as wood enters the bloodstream and has been found in internal organs resulting in long term damage to human health as well as having more immediate impacts for some people such as breathing problems or asthma attacks"