Crowdsourced Air Monitors Could Help People Breathe Easier in Cities

by Michael Keller

People living in towns and cities across the U.S. generally rely on state and federal authorities to let them know when their community’s air quality is cause for concern.

Monitoring station coverage varies depending on what state you’re in. Even if a monitor is down the street from you, the number of pollutants it sniffs for might be very different from another unit acrosss town. One station might be monitoring for ozone and nitrogen oxides, while a distant one might be on the lookout for sulfur dioxide and tiny particulate matter. That isn’t a recipe to give a consistent or personally very useful assessment of the air you’re breathing.

And for many people, an air quality monitoring station isn’t nearby. The state of the air on individual blocks or in neighborhoods is often unknown. But what if the job could be shared, with sensitive government equipment remaining in a dispersed network across a city while interested citizens provide data between the stations?

A European project called Citi-Sense is looking to do just that. Their goal is to develop sensor-based networks that are crowdsourced by citizens who measure the environment and conditions in urban areas.

“Our ultimate goal is to develop this sensor-based citizens’ observatory community in urban areas,” said Alena Bartonova, the Citi-Sense project coordinator, during a recent meeting of the American Association for the Advancement of Science. “We are working to create the sensor infrastructure while also figuring out how to involve citizens in this. Involvement is one of our main challenges.”



Scientists in Europe and U.S. who are working on the technology part of the project recently showed the importance of getting more granular data about local conditions a person moving about a city will experience daily. In a paper published recently in the journal Environmental Science & Technology, they gave schoolchildren customized smartphone-based sensors that could measure airborne black carbon, an indicator of traffic-based air pollution. The device captured location, physical activity and continuously monitored black carbon levels. They found significant variation of exposure to air pollution as the students went from home to school and back again during the day, with the highest exposures coming during their commutes.

“Novel technologies, such as smartphones and small personal continuous air pollution sensors, can now facilitate better personal estimates of air pollution in relation to location,” the research team wrote. “Such information can provide us with a better understanding about whether and how personal exposures relate to residential air pollution estimates, which are normally used in epidemiological studies.”



(An example of the smartphone-based black carbon air pollution personal monitoring kit given to students to test the variability in their exposure during the day. Image courtesy of Nieuwenhuijsen et al./Environ. Sci. Technol.)

Bartonova said studies like the black carbon evaluation have shown that children would be the easiest group to get involved in the distributed monitoring initiative.

Key will also be developing a simple, practical device that monitors a basket of different air pollutants. The group also plans to launch a web portal that serves data to citizens, a necessary step to give those who choose to collect data something back for their efforts. This could also be the first stage to developing specialized apps for those involved in the Citi-Sense project. User specific programs could, for instance, guide cyclists around areas of heavier pollution onto routes with cleaner air. Other products could tell people when noxious gases or strong odors are coming their way.

“The aim is to empower people in environmental decision-making, to give them new tools to assess their environment and bring them together in a citizens’ observatory,” said Mark Nieuwenhuijsen, an epidemiology researcher at Spain’s Center for Research in Environmental Epidemiology who coauthored the study and works on the Citi-Sense project.



Top Gifs created from Vimeo video courtesy of the European Service Network.