Amid efforts by the Trump administration to broadly loosen national air quality regulations, the city of Chicago has undertaken a significant air quality monitoring program with placement of 277 air sensors collecting data on fine particulate matter (PM2.5) and nitrogen dioxide (NO2).
Chicago first installed the Clarity Node-S sensors last summer, but in February began promoting the ability of residents and communities to track air pollution in various neighborhoods through an Open Air Chicago dashboard.
The effort so far does not appear to be pointed to any single polluting source for legal enforcement, but instead to raise the level of awareness for communities most affected in a data-gathering effort. The new sensors will supplement previous federal-grade monitoring systems.
City officials have said the deployment of its 277 sensors is expected to be among the largest number of air quality sensors in any one city globally. London operates a network of more than 400 sensors in the Breath London network.
Placement of the sensors is a notable achievement of smart city planning, with less than a mile between sensor locations. The placement relied on US EPA Clean Air Act Network Design Criteria but also Chicago Environmental Justice Index scores, community input and the location of light poles.
“Installing air sensors across our city is imperative in assessing what risks there are and protecting community members, especially those most vulnerable: children, older folks and people with respiratory illness,” said Chicago Department of Public Health Commissioner Olusimbo Ige, in a published statement. Data gathered will be used to “guide the development of interventions to improve the health of Chicagoans.”
Residents can now use an online map to identify air sensors nearby and assess air quality levels and 24 hour trends, as well as review health recommendations related to the current air quality, which can instruct them whether vulnerable people may need to wear masks or stay indoors. There is also an open data portal to download raw and weighted data for individual measurements, as well as day and hour aggregations.
Chicago health officials have long noted the correlation of air pollution to its impact on vulnerable populations that include children, older adults, pregnant women and their fetuses, people with asthma and other chronic diseases and people of color and those with lower incomes. Outdoor workers and people living near sources of pollution are also more vulnerable.
The tech behind Clarity Node-S sensors
The tech behind the installed Clarity sensors began emerging several years ago, but the Berkeley, CA, company has since expanded its work globally. Clarity Node-S sensors use a fan to draw air into a chamber, where a laser scattering beam identifies and counts particulates. Sensor modules also monitor NO2.
The sensor operates in cycles of 90 seconds of sampling, and up to 120 seconds of transmitting data via cellular to a Clarity Dashboard and a then a 15-minute sleep/low power mode. They are designed as solar powered and completely wireless, with battery backup. Data is calibrated remotely. Individual sensors vary widely in price from $200 to $1,300 apiece, according to several published user examples, depending on the volume and applications used, but the company offers a sensors-as-a-service approach as well. Hardware specs are online.
Environmental sensors are gaining credibility with cost-conscious governments and organizations, according to analyst Jack Gold, president of J. Gold Associates in comments to Fierce. “Deploying sensors to understand the environmental impact has taken on new meaning since many newer technologies built into the sensors both boost accuracy while also making it less costly and simpler to deploy. That means application areas that were not feasible before are now becoming possible," he said.
Chicago's strategic approach
Open Air Chicago is related to a comprehensive, data-driven approach to analyzing health of Chicagoans in the city’s Healthy Chicago 2025 Strategic Plan which aims to address health disparities and improve life expectancy among Chicagoans with a focus on racial equity and community health. It is a broad plan that looks well beyond the impact of air pollution and includes assessments of mental health, chronic disease, substance abuse and violence. The plan found that five communities in the city have as much as an 11-year lower life expectancy gap for black vs. non-black Chicagoans: West Garfield Park, North Lawndale, Englewood, West Englewood and East Garfield Park.
Trump's clean air policies
Nationally, clean air advocates have raised concerns about Trump administration programs to weaken or roll back rules about emissions from cars, power plants and industrial facilities. President Trump has justified his efforts as a means of promoting economic development, especially as industries have raised concerns about too much regulation limiting growth. Early in his second term Trump called for greater use of coal in creating energy, among other resources, and has backed the ability for data centers to co-locate energy generating operations with data centers vital to AI compute operations.
In November, the US EPA stopped defending national limits on particulate matter (PM2.5), also known as soot, which had been strengthened under the Biden administration. Soot can contain tiny toxic particles that lodge deep in the lungs, linked to premature death. Soot comes from vehicle exhaust, power plants and factories.