With a sprinkling of hardware and software, he was able to get these cheap laser particle sensors working on his ... gives a running output of the PM1, PM2.5, and PM10 measurements.

Given such a sensor, you can measure VOCs and NOCs (Volatile and Non-Volatile Organic Compounds), as well as PM1, PM2.5, PM4 and PM10 particulate matter indices, with temperature and humidity ...