New Air Quality Monitoring App Aims to Protect Students in Polluted Bay Area Communities 

In Richmond, Peres K–8 School is surrounded by a Chevron oil refinery, a Phillips 66 petroleum pipeline and Interstates 80 and 580. When students go outside for recess, they inhale pollutants like fine particulate matter from those sources, which can lead to respiratory problems. The prevalence of asthma among the city’s residents is 25% compared with 13% statewide. 

Peres is one of many schools in polluted Bay Area neighborhoods. A new app aims to provide school administrators and teachers in these communities with real-time data that can help them protect students from harmful air pollution. When air quality is especially poor, teachers might keep kids inside during recess and a coach might cancel or move a sports team practice, said Kristina Hill, an associate professor at the University of California, Berkeley. Hill and her research team developed the tool in collaboration with Charisma Acey, also an associate professor at UB Berkeley, and a focus group of advocates from five Bay Area communities with high levels of air pollution. 

The app offers an interactive map where Bay Area residents can see hourly readings of the air quality in their area. It draws on the existing PurpleAir monitor network but adds key improvements like correcting for errors caused by fog and combining data from multiple monitors to paint a clearer picture of air quality in a neighborhood. 

The tool, called the Bay Area Community Air Quality Map, is available in beta version. After final refinements, its developers will begin encouraging schools to adopt it. They hope the tool will help usher in a culture of regularly checking air quality in communities with air pollution. 

Marisol Cantú, a project supervisor for the Richmond Progressive Alliance who participated in the focus group, wants to see schools use the app when classes resume in the fall. She believes people in Richmond will welcome the tool. 

“Because we live by the Chevron refinery, there is not a single moment when Richmond residents aren’t thinking about our environment,” Cantú said. “It’s in our blood. It’s in how we move.” 

The health costs of bad air

Besides asthma, air pollution can boost risk of a range of ailments including diabetes, heart disease and stroke. Fine particulate matter, the pollutant the PurpleAir network measures, has been linked to developmental delays in children and various cancers. Research is still emerging on its effects, and its harm is likely much greater than we yet know, said Hill. 

Because children’s brains, lungs and other organs are still developing, they are especially vulnerable to the harmful effects of air pollution, she added. And the health costs of air pollution exposure build up over time, she said. 

“It’s like your lungs are fly paper,” said Hill. “It’s damaging and adds up over your lifetime.” 

Improving air quality maps

While readings from individual PurpleAir monitors were already publicly available, that data often wasn’t useful in Bay Area communities with the most air pollution, said Hill. Because the monitors typically cost between $200 and $300 each, they were common in affluent neighborhoods and rare in poor and working-class neighborhoods. That often left holes in the network’s coverage where air quality was the worst. The new tool smooths the data across available monitors to give people an estimate on their local air quality, even if there isn’t a monitor close to them. 

Though PurpleAir monitors are widespread because they are cheap relative to more high-tech sensors, they are notoriously imprecise because they get befuddled by fog. Hill added a correction factor that adjusts for humidity, which has enabled the app to offer hyperlocal and accurate air quality readings. 

Hill said other publicly available air quality maps draw on information from sensors that are mounted several stories off the ground, while the new app draws on sensors closer to the ground, at what some call “breathing level.” In communities burdened with heavy industry, a sudden event like a flare from a refinery or a truck idling can affect hyperlocal air quality. Other public maps might not display such granular details.

The new app also offers a feature that enables users to report incidents like a flare to the Bay Area Air Quality Management District, which regulates air pollution locally. 

Until now, available air quality maps were unintuitive to use, said focus group member Sharifa Taylor, the Northern California staff researcher at the advocacy organization Communities for a Better Environment. 

When opened, the standard PurpleAir network map presents a world map from which users must navigate to their community. Not everyone knows how to navigate a world map, said Taylor, and that interface simply wasn’t built for people to check on a daily basis. 

The new map offers a hyperlocal measurement network and is color-coded to give people quick feedback on the hazard level of the air quality outside. Most people will intuit the meaning of colors like red and green based on their experience with traffic signals, said Taylor. Hill hopes to add a “favorite” feature soon to enable people to immediately learn the air quality at a school near them. 

“A tool like this is vital because it lets people know: ‘Am I safe or not safe?’” said Taylor. 

The development team built the app to help people decide how to go about their day. Hill hopes to encourage a culture of checking air quality regularly to help people protect themselves. 

“Everybody who’s going to go on a run or a bike ride should check the map first,” said Hill. 

UC Berkeley undergraduates on her team are planning a promotional push that includes swag and a social media campaign — an unusual turn for university research. But meeting regular people in their own communities is a guiding principle of the app, said Hill. 

“The project really tore down the ivory tower wall between academia and communities,” said Cantú of the Richmond Progressive Alliance.

As the Trump administration removes data and slashes federal funding for environmental justice initiatives, this app is providing critical information to help Bay Area residents protect themselves, said focus group member Arieann Harrison, executive director of the Marie Harrison Community Foundation, an environmental justice organization. 

“We’re in an environmental sacrifice zone from San Francisco’s Bayview-Hunters Point to Richmond to Oakland,” said Harrison, who lives and works in Bayview-Hunters Point. “To me, it’s not just about creating long-term policy changes, it’s about creating tools to protect the most vulnerable right now.”

Editor’s Note, 6/24/25: This story has been updated to more accurately characterize the details captured by the Bay Area Community Air Quality Map that are not available on other public air quality maps.