Some areas are currently experiencing health warnings to stay inside due to poor air quality caused by smoke from wildfires causing high PM2.5 levels. How does the health risk depend on the PM2.5 level of particular matter in the atmosphere and the duration of exposure? Is there a quantitative model to predict the risk? (e.g., x amount of μg/m3-hours leads to a y amount of risk of death)
I found a study (https://doi.org/10.1136%2Fbmj.f7412) which reported that a 5 μg/m3 increase for a year leads to a 13% increase of coronary events. If we crudely estimate about 0.0025 coronary events per year, and estimate that 80% of them are fatal, then 43800 μg/m3-hours corresponds to about 0.002 extra deaths per year per person, or about 0.05 micromorts per μg/m3-hour of increase in PM2.5. There are any number of ways this estimate might be off, though. Is there a better estimate? Also, is the risk expected to be a linear function of the PM2.5 level multipled by the number of hours of exposure, or is it a nonlinear function? Does it depend on the level of activity as well, or the age of the individual?