LA Unified School District and CCA build the nation's largest school-based outdoor air quality sensor network

Protecting the health of >500K Los Angeles students from air pollution

The Los Angeles Unified School District (LA Unified) supports over half a million students across more than 1,400 schools in the city. This makes for a unique challenge for the District’s Office of Environmental Health and Safety, which is responsible for a wide range of environmental management duties — including protecting LA Unified students and staff from the air pollution issues the region faces. 

Los Angeles contends with the most severe ozone air pollution in the United States, along with frequently high particulate matter levels, due to vehicle and industrial facilities emissions. As climate change fuels wildfires raging longer and more intensely each year, the region also battles thick smoke descending into neighborhoods with increasing frequency. 

As heavy wildfire smoke became an increasing occurrence, exacerbated by already unsafe air quality, Carlos Torres, Director of LA Unified’s Office of Environmental Health and Safety, realized that they needed real-time, localized air quality data to help make immediate assessments to protect student and faculty health. 

Developing a high-resolution air quality monitoring network

The concept for investing in an air quality monitoring network originated from urgent inquiries regarding air pollution during severe wildfires. When smoke descends on Los Angeles, fine particulate matter pollution surges to hazardous levels — and as the air quality index skyrockets, so do inquiries from concerned administrators and parents.

At the time, the only way for me to answer leadership’s urgent questions was to get in my car or have someone get in their car and go out there.” 

—  Carlos Torres, Director of Office of Environmental Health and Safety at LA Unified

‍At the time, LA Unified relied chiefly on sparse government reference monitors from South Coast Air Quality Management District spread thinly across the immense 710 square mile district. But air quality levels can fluctuate neighborhood by neighborhood, leaving room for wide variability in air pollution concentration across such a large area. In most cases, assessment of air quality could only occur once safety inspectors would arrive at a school with handheld monitoring equipment, an inefficient and untimely process. 

To tackle this pervasive issue, LA Unified pioneered a groundbreaking solution — constructing the nation’s largest school-based ambient air quality monitoring network.

In partnership with the nonprofit Coalition for Clean Air (CCA) and Clarity Movement, LA Unified launched the Know Your Air monitoring network, consisting of more than 200 Clarity Node-S air pollution sensors spread strategically across LA Unified schools to deliver hyperlocal air quality data. 

Galvanized by outspoken advocates across LA Unified leadership — especially Board Member Nick Melvoin — Torres and CCA gained funding and support to pioneer a first-of-its-kind school-based air quality monitoring network. In 2019, CCA secured funding from the Wells Fargo Foundation and the Zolla Family Foundation for LA Unified to conduct a 22-unit pilot study, installing Clarity’s Node-S air quality sensors at select schools. 

The units transmit hyperlocal air quality data, providing reliable PM2.5 readings securely via cellular networks. Unlike other low-cost sensors, the Clarity Node-S had the attributes LA Unified needed — cellular data connectivity, solar-charged battery-powered operation, and superior data quality. As Joe Lyou, President and CEO of CCA described, Clarity’s attention to air pollution data quality was an important factor in selecting the Node-S for the project.

The devices worked and the data were much better than other low-cost sensor data — Clarity pays attention to and cares about trying to get as accurate data as possible.”

— Joe Lyou, President and CEO of CCA

Bolstered by a successful trial, LA Unified implemented Phase II in 2022, strategically deploying units at schools using an EPA neighborhood-scale model — with the outcome being an air quality sensor installed within 1.6 miles of each school in the district. 

Today, LA Unified's more than 200 air pollution sensors deliver live air quality data updated every 5-10 minutes. The solar-powered air quality sensors transmit real-time fine particulate matter (PM2.5) readings via cellular networks to the Clarity Cloud, where air pollution data are easily visible to Environmental Health & Safety personnel through the Clarity Dashboard. 

This real-time network enables decisions by LA Unified leadership, and individual schools to reduce student air pollution exposure. School Administrators, parents, and the public can also access real-time air quality levels through the public-facing LA Unified website or via notifications.

Check out the interactive map below to see real-time air quality data for Los Angeles! 

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How teachers and administrators use hyperlocal air quality data

The Know Your Air Network equips LA Unified teachers, faculty, and headquarters staff with current, localized air quality data for daily operations and emergency response. During wildfires or air pollution events, administrators reference the network to identify impacted schools in real time and take action to mitigate student and staff exposure to harmful air quality. 

We can check the network and see if there are any outliers within seconds. That instant localized information is invaluable for quick and informed decision-making across a district of our scale.” 

—  Carlos Torres, Director of Office of Environmental Health and Safety at LA Unified

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The network also enables the detection and troubleshooting of pollution sources like idling vehicles — a common air quality concern at schools, especially when parents are waiting to pick their children up after class. 

Beyond emergency mitigation, LA Unified schools are utilizing Know Your Air data for their environmental science curriculums — Lyou believes engaging youth is crucial for building air quality awareness. 

There are studies that show the importance of doing everything we can to minimize exposure to air pollution. It’s really a perfect mechanism to start informing some of the curriculum."

— Joe Lyou, President and CEO of CCA

Students can examine air quality trends over seasons, years, and events to understand patterns. They can even view time-lapse videos of air quality trends (see, www.ccair.org/time-lapse/). They can also brainstorm solutions and engage in problem/solution projects to reduce neighborhood air pollution through personal, school, and community actions — fostering environmental awareness and stewardship skills that will serve them throughout their lives.

An air quality monitoring model for school districts worldwide

LA Unified’s Know Your Air Network provides a powerful blueprint for school districts across California, the US, and the world in addressing air pollution. 

While LA Unified is a massive district with a significant budget, Lyou emphasized that the model can scale. 

I would hope that other school districts would use this as a template. It makes sense for some of the bigger districts that have the resources and have a wider geographic area, but it would make sense for small districts too.”

— Joe Lyou, President and CEO of CCA

Lyou also explained that rolling out an air quality monitoring network doesn’t necessarily need to include complex logistics or planning. “As we’ve learned in the short time that we’ve been doing it, it really doesn't take a whole lot to get started," he said, referring to the initial 22-sensor trial LA Unified conducted. 

Districts can start with a small air quality monitoring pilot to prove value before scaling. Clarity and partners like CCA can provide guidance on planning, funding, sensor distribution, community engagement, and more to set the stage for success.

Access to hyperlocal real-time air quality data provides immense value to school districts small and large. During wildfires and air pollution episodes, administrators can instantly identify impacted campuses rather than relying on broad regional estimates. 

Installing on-site air quality sensors allows districts to take ownership of their air quality data, accelerating issue awareness and mitigation. Relying solely on government monitors creates information gaps while amassing local data fosters empowerment. Lyou believes that “the ability to crowdsource the data, the ability to have some control over where and what gets monitored” lies at the heart of community air quality improvement.

Looking into the future, LA Unified plans to expand the monitored pollutants across its network, incorporating additional critical data on air pollutants like ground-level ozone. This strengthens understanding across all air quality indicators. 

LA Unified also aims to continue integrating its air data further into more schools through curriculum and supplementary programs like CCA’s Clean Air Day. This drives greater student engagement toward solving neighborhood pollution.

Ultimately, Torres and Lyou hope to inspire replication globally. “I'd love to see other school districts implement similar networks,” Lyou said. “You can take care of this right away, easy.” As climate change accelerates regional air pollution challenges, school districts must safeguard respiratory health across their communities. 

LA Unified’s pioneering program provides a roadmap to start that journey with hyperlocal air quality data as the compass guiding decisions. One day in the not-so-distant future, we may wake to find air quality sensors as ubiquitous on school buildings as security cameras or wifi routers. 

Through efforts like LA Unified’s Know Your Air Network, we can move closer to a world where every student breathes clean air at school.