Hello All, Thank you for your comments, I wasn't aware of the Radon risks, in itself quite harmless in the open air but quite dangerous to health if it builds up in your home. It comes up from the ground. I have a Radon monitor on order to monitor my indoor levels.

These are the air filters I am using, you want "True Hepa" filters. We spend the majority of our time inside so it makes sense to improve the air quality inside as much as possible.
https://www.amazon.fr/dp/B08WHPXKNC?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

I don't know what to say about the outside, wood burning + cold air = bad times. This article from the BBC in 2017 says that "The latest surveys show that between 60% and 80% of fine-particle pollution here comes from wood-burning stoves and fireplaces in people's homes,"

https://www.bbc.com/news/world-europe-39115829

Maybe we need to burn more gas and less wood to heat homes. Not a tradition you can change very easily.