City officials are scrambling to install almost 300 high-quality air-pollution sensors across Chicago, a network that would be the largest in the U.S. and one of the biggest worldwide.
The plan is to have the monitors up by the end of summer as city officials try to get a handle on the poor air quality that severely affects the polluted Far South Side, Southwest Side and West Side neighborhoods.
The sensors will not be used to enforce pollution violations, however. Their use is intended to help shape city planning and practices around industrial development, planning, zoning and land use and establish public health safeguards to mitigate the pollution.
“This is going to be a very big network of air monitors — more than any place in the nation,” said Myrna Salgado-Romo, who has helped advise the city in her role as network manager for the Chicago Environmental Justice Network. “Hopefully, it informs future policies.”
In total, there are 277 monitors that are being installed across Chicago, according to the city. The devices were purchased with government and private grants awarded to University of Illinois Chicago, a partner in the city’s effort, and Chicago’s public health department.
So far, almost 140 air monitors have been installed on light poles around the city and almost half of them were put up this past Saturday. The city plans to install more this weekend to meet the end-of-summer deadline.
The race to get the monitors up by next month follows a promise by Chicago Public Health Commissioner Olusimbo Ige to City Council members earlier this year to get the sensors up and running in that time frame.
Ige was under pressure to act on pollution monitoring after she pushed out Raed Mansour, the city’s air pollution expert, late last year even as he seemed to be close to launching a network of sensors by early 2025.
The circumstances around Mansour’s ouster are still unclear. Mansour and a political appointee of Mayor Brandon Johnson had a disagreement during a public meeting. Shortly after, he was forced out of his job. Mansour, the architect of the plan now being deployed by the city, declined to comment.
The Los Angeles school district has the biggest network of air monitors in the country with more than 200. London has the biggest air-pollution sensor network in the world with more than 400. Chicago is using the same type of air monitors, produced by a company, Clarity Movement, which are considered relatively low-cost but high quality devices.
The Clarity sensors are higher-quality than inexpensive models by companies, such as Purple Air. But they’re not the high-grade devices used by the Environmental Protection Agency for enforcement.
Research by city health and other organizations over more than a decade has shown that West Side and South Side communities have the worst air quality.
Those areas of the city are hit with poor air well beyond the days when all of Chicago is blanketed with a smokey haze from wildfires raging in Canada or the Western United States. At times, those fires have elevated Chicago to the most-polluted big city in the world.
Johnson introduced a proposed environmental protection law earlier this year that aims to slow or end the practice of putting polluters in the same low-income communities of color on the South Side and West Side of Chicago that already suffer from bad air. Supporters hope the measure will be debated in the coming months.
There have been attempts in the past to create a citywide network of air sensors, most recently by Microsoft. But those efforts have had limitations. For instance, the Microsoft monitors didn’t cover the entire city and their placement on bus shelters raised questions about accurate readings.
Part of the University of Illinois Chicago’s funding for air monitors came from ComEd, which is interested in exploring the environmental impact of electric vehicles in areas affected by pollution.
“Investments to install air quality monitoring are geared toward better understanding the benefits of [electric vehicles] in areas experiencing poor air quality,” ComEd said in a statement.
Cars, trucks and other vehicles that use gas and diesel fuel are the biggest contributors to greenhouse gas emissions and are linked to premature deaths and diseases.
Data from the sensors will be available publicly most likely by early 2026, the health department said.