100% agree. It is super important to know the composition of the particles.

Unfortunately currently only super expensive instruments can measure this in real-time.

This is why I believe contextual information will become much more important in future.

Detect an indoor short PM2.5 spike around lunch time, probably a cooking event.

Detect medium elevated levels outdoor in a city in the morning and late afternoons, probably traffic related smoke.

I actually made a small tool to simulate different events that contain a quiz. Give it a try here [1].

[1] https://www.airgradient.com/air-quality-monitoring-toolkit/p...