My daughter participated in a study. I am so glad she did. In our area, a lot of people began burning wood to heat their homes when gas prices increased. Our community's air quality plummeted - and we had problems to begin with. My daughter was spending week on, week off between me and her Dad.
Anyway, the study was supposed to compare cleaner burning wood stoves with good air filters. Her dad's family wound up getting a free, cleaner burning wood stove to replace their less efficient model. She was given a digital peak flow meter to use during the study, and I found it so useful I bought her one to keep.
It was a great experience that helped her and led to a better understanding of how wood burning in a community can be managed safely for asthmatics.