The city completed installation of 277 pollution sensors and said it will make data publicly available early next year, allowing residents to get a detailed look at air quality in their own neighborhoods.
The devices are located throughout the city and all 50 wards have at least one sensor, according to Chicago public health officials.
The effort is believed to be the largest of its kind in the U.S. and has been a priority for residents who live in the most polluted areas of the city, including West Side and South Side communities. Past air-quality assessments have shown that areas with a lot of industry or heavy traffic are more polluted and have greater health risks than other parts of the city.
The devices, located on lightpoles, will measure levels of a fine particle pollution, known as PM 2.5 as well as nitrogen dioxide, which is a gas that forms from the burning of fuel, such as diesel.
Both types of pollution have a severe effect on respiratory systems and can be particularly dangerous for people with asthma, lung disease and similar conditions, even leading to premature deaths. Analyzing the local conditions can help inform policies around health protections.
“You can’t make decisions without data, and air quality is something that varies block to block,” said Charlie Catlett, senior computer scientist at Argonne National Laboratory.
Catlett worked more than a decade ago on Chicago’s first large-scale system of sophisticated air sensors. Known as Array of Things, the Argonne and University of Chicago-led effort ended after a few years.
The sensors that the city recently installed are far more advanced than those used under that program, Catlett said.
For this latest effort, the city partnered with the University of Illinois Chicago to purchase the sensors and launch the monitoring effort. This is the first time that the city has taken the lead on the pollution monitoring.
The new plan marks the third time that a pollution-monitoring network has been installed in Chicago.
Following Array of Things, Microsoft installed more than 100 sensors on bus shelters, though that network left large areas of the city unmonitored. The placement on bus shelters raised questions about accuracy of the air readings. The company ended its project after less than two years, saying it would invest in other programs.
Chicago Public Health Commissioner Olusimbo Ige promised City Council members earlier this year that the sensors would be up and running before the end of summer. That pledge followed a delay in the monitor program after Ige pushed out the city’s expert on air pollution.
“Installing air sensors across our city is imperative in assessing what risks there are and protecting our community members,” Ige said in a statement to the Sun-Times Thursday.
Until now, the Los Angeles school district had the largest network of air monitors in the country with more than 200. An air-pollution sensor network London is the biggest in the world with more than 400.