According to this project’s Hybrid Ecologies writeup, in 2013, air pollution was estimated to have caused 3.7 million deaths. The primary cause of this were particulates of 10 microns or less, which can lead to the development of cardiovascular and respiratory diseases. To help with this problem, the MyPart team developed a particle sensor that can be worn on one’s wrist like a watch.
It works by sucking air into its measurement chamber, then measuring laser light that’s passed over it. Depending on how this light responds, these “particle watches” can then report their findings to a user’s smartphone using an RFduino to communicate via Bluetooth.