Researchers at Germany's Karlsruhe Institute of Technology have developed a smartphone-connected tool that can sense dust levels, which can be an important metric for some public health issues. When tested, the technology showed a good initial performance, but a paper describing the research explains that future iterations of the tool will offer increased sensitivity so that the device can detect even lower concentrations of dust.

"Past studies have shown that exposure to fine dust can pose a serious health hazard," the study authors write in the paper. "Beyond omnipresent sources of particulate matter (PM), e.g. traffic, risks can also occur at home or in a working environment. A good example are laser printers, the fine toner dust from which can even result in permanent disability if inhaled over years."

While portable devices that monitor dust currently exist, researchers say they currently range from $1,000 to several thousand dollars. 

So far the research team has developed an active version of the device that uses an external LED and a passive version of the device that re-routes light from phone’s LED flash. To use the device, users would attach the sensor their smartphones and take the measurement via photo or video. The app would then assess the pollution and display this data for the user, but also send the information to a computer system that receives dust level updates from all users.

In future research, researchers hope to improve the device's form factor and design an online calibration procedure for scenarios in which people are sending in data from many different regions.

A similar dust-sensing system was developed a few years ago. Doctoral students from the University of California San Diego developed an app in 2012 that connected to pollution sensing wearable devices. The group used to tool to conduct a study in which 16 people who used different methods of transport but all had a 20 minute daily commute measured pollution while traveling. The study found that the participants' measurements varied significantly from those provided by official regional pollution monitoring stations.