PM2.5 have decent accuracy and are certainly useful at low price points, RH/temp work fine, particularly with separate sensors. Pressure works fine but is pretty useless. NDIR based CO2 (ex. Sensirion SCD31 or 41) also work fine.

TOC is a bit of a mystery, it can probably detect relative change. I've used them in a lab to monitor solvent vapor and you can detect changes, hard to quantify but don't need to most of the time.