Many researchers are creating sensing equipment to crowdsource environmental data. These technologies could soon be used to supplement data collected by the city, with the benefit of being much cheaper than professional equipment. While data collected by professionals is highly accurate, a large enough number of low–cost sensors will produce results that are good enough to allow policymakers to make decisions about air quality.

One of the most promising examples of this technology is the PiMi Airbox developed by Tsinghua University. Individual devices achieve a much higher level of accuracy than similar low–cost sensors and they also upload all the data they collect to create a crowdsourced map of indoor air pollution in Beijing.

While researchers get a crowdsourced map of the air pollution in the city, volunteers who host the kit are more interested in what it can tell them about the air quality in their homes. The ability of the device to measure PM 2.5, the smallest and most dangerous type of particulate matter, is one of the reasons it has proved so popular. Over 500 people volunteered to host a PiMi Airbox within a day of the project being launched.