Wildfire smoke sparks an air quality dialogue in central San Francisco

As the Executive Director of Brightline Defense, Eddie Ahn works closely with stakeholders from community groups and government agencies across the Bay Area. Through conversations with the Central City SRO Collaborative (CCSROC) and other community organizations, Ahn came to realize that many of the city’s health and quality-of-life challenges could be traced to the same root cause: poor air quality.

As is the case in so many urban environments, air pollution in San Francisco has long been a health risk that is hidden in plain sight. 

Air quality is a hidden issue in the sense that it's become so embedded in aspects of urban life in San Francisco. It can be a challenge for residents who have been living in the neighborhood for a long time to articulate what their air quality issues are. Some have just accepted it as a way of life.”

- Eddie Ahn, Executive Director of Brightline Defense

Communities in San Francisco have long been plagued by air pollution from a range of sources, but because air pollution tends to be invisible to the naked eye, this environmental inequity had largely been overlooked. 

The South of Market (SoMa) neighborhood in San Francisco is a good example. Several highways and freeways are directly adjacent to SoMa, so as congestion increases across the region, it's always been SoMa that's impacted by those highway emissions. You have schools right next to the freeway in this neighborhood, and students are having to breathe in those pollutants that are coming from cars.”

- Eddie Ahn, Executive Director of Brightline Defense

Apart from freeways, several emission sources impact air quality in central San Francisco, such as the diesel emergency generators prevalent in the northeastern sector of the city. Larger commercial buildings rely on these emergency generators to keep the lights on in the event of power disruptions or blackouts - but while generators may be useful for reliable power supply, they can wreak havoc on local air quality. 

Aging buildings mean elevated air pollution exposure for SRO residents

Single-Room Occupancy (SRO) hotels tend to be aging buildings that were designed to accommodate an immigrant workforce around the turn of the 20th century. In recent years they have been transitioned into affordable housing, but many of the buildings themselves have not been retrofitted for over a century. These buildings have poor ventilation and out-of-date HVAC systems. They also tend to be overcrowded - often families of four or more individuals will share a small room of less than 100 square feet. 

Due to the location and architecture of these buildings, residents of SRO hotels face some of the most direct exposure to local air pollution. This population is especially impacted during catastrophic air quality events and wildfires because they don't have the modern infrastructure to help filter pollutants brought in by poor outdoor air quality. 

The Bay Area faced some of the worst air quality on record during the 2020 wildfire season, logging 30 consecutive Spare the Air days. San Francisco logged a maximum recorded 1-hour AQI of 247 per BAAQMD data on September 11th. These events brought air quality to the forefront of the dialogue at the CCSROC. 

Air quality issues have been embedded in these communities for years, but it has been the intensity of the wildfires over the past few years that prompted a dialogue. Once we started looking into how exposure to toxic wildfire smoke impacts these neighborhoods, we saw how critical improving air quality would be to improving the quality of life in these communities. It became clear that implementing an air quality monitoring program would be the first step to filling that gap.”

- Eddie Ahn, Executive Director of Brightline Defense

Brightline engages stakeholders across San Francisco to establish objectives for the city's air quality monitoring program

Ahn realized that while SRO communities would be some of the first to experience the benefits of an air quality monitoring program, a range of stakeholders across the city that could benefit from the accurate, high-resolution air quality data generated. He began thinking about policy objectives that would be supported by data from an air quality monitoring network. 

In addition to raising community awareness about air quality, there are longer-term policy issues we'd like to influence with data from the network. One example is cleaning up our vehicle fleet - converting city buses to electric, for instance. “Slow Streets”, or car-free streets, is another interesting program that has become more prevalent with the COVID-19 pandemic. A local air quality monitoring network would allow us to study the program’s impacts on traffic congestion and air quality in the surrounding area.” 

- Eddie Ahn, Executive Director of Brightline Defense

With objectives for the program identified, Ahn set out to find funding for an air quality monitoring network in central San Francisco. 

Brightline obtains funding for a high-resolution air quality monitoring network through AB 617

AB 617 air quality monitoring programs are funded through California Climate Investments

Ahn knew that funding was available for community-based air quality monitoring projects through an innovative new policy from the California state legislature known as AB 617, or the Community Air Protection Program. Through conversations with other nonprofits, he learned that Clarity Movement Co. (Clarity) had supported other communities establish air quality monitoring programs through the AB 617 program and could help Brightline apply for funding through this program, which is backed by California Climate Investments. 

Brightline has worked with many private sector stakeholders in the past, and Clarity stands out to us as a company that cares. They have spent the time and effort listening to the concerns of the community and adapted their technology accordingly.” 

- Eddie Ahn, Executive Director of Brightline Defense

Brightline was awarded funding to deploy a network of 15 air quality monitoring devices in several San Francisco neighborhoods, which later expanded to 19 because of increased community demand. The timing could not have been better, as the funding came through just in time for Brightline to jump into action and deploy the monitoring network as wildfire season began across California. 

Through the smoke: deploying an air quality monitoring network under emergency conditions 

With funding approved and wildfire smoke clouding the region, Ahn teamed up with Brightline colleague Daniela Cortes to rapidly deploy the air quality monitors at select sites across the city.

Ahn works to install a Clarity Node-S air quality monitor on a San Francisco streetlight amidst wildfire smoke.


Having a self-sufficient device like the Clarity Node-S was key for rapid deployment during the wildfire events. Our nonprofit installed 19 monitors in less than 2 months. We were making emergency requests to city agencies, nonprofit affordable housing developers, and local businesses to gain access to their facilities or rooftops to install these devices. I can only imagine how much more difficult it would have been if we had to arrange access to Wi-Fi networks for connectivity or electrical outlets for power - fortunately, the Node-S is hearty, weatherproof, solar-powered, and operated by a cellular network.

- Eddie Ahn, Executive Director of Brightline Defense

As Ahn and Cortes worked to install the monitors, the Clarity team was there to support every step of the deployment process. Clarity helped Brightline to select deployment sites and provided real-time counsel via a messaging app while the Brightline team was in the field for deployment. Brightline sent photos to Clarity, who provided detailed recommendations on appropriate placement for the devices. 

The Clarity team provided real-time deployment support - having that kind of attention to detail was helpful. We sent photos of the devices, and Clarity provided detailed guidance on where to place the monitors so that there would be no impediments to accurately measuring AQI.”

- Eddie Ahn, Executive Director of Brightline Defense

After the grueling work of installing monitors amidst toxic wildfire smoke, Ahn and Cortes had deployed 19 air quality monitors and established a new foundation for the collection of local air quality data in San Francisco. 

Brightline air quality monitoring program coordinator Daniela Cortes installs a Clarity Node-S on a rooftop in the Tenderloin.  
The communities Brightline serves are disproportionately burdened by pollution exposure and have little to no access to adequate air filtration. Our sensor network not only empowers them with real-time local data but equips them with the tools and knowledge to make informed decisions in regards to their air and their health.”

- Daniela Cortes, Program Coordinator of Brightline Defense 

Taking ownership of air quality monitoring data with the Clarity Dashboard

With the network up and running, Brightline shifted focus to learning how to work with air quality data from the network. The Clarity customer support team helped Brightline set up their Clarity Dashboard and coached them on how to understand and analyze their data. 

The Clarity Dashboard is designed to help draw actionable insights from air quality data. 
As the administrative lead for this program, Brightline wants to make sure we can take all these data streams and analyze them to highlight important air quality issues that the community should know about. Breaking down these data streams is work that requires an understanding of how to look at AQI and the measurements coming in. Coming up the learning curve on air quality has been a challenge, but Clarity’s team helped facilitate our understanding of the air quality space as a whole. We are now checking in with the Clarity team about once a month to touch base about the network and learn how to use the Clarity Dashboard. Having all of our data available in a secure web portal is very useful, especially as we prepare data reports. ”

- Eddie Ahn, Executive Director of Brightline Defense

Brightline engages stakeholders across the community with an air quality monitoring network

Since the monitoring network was installed in August 2020, Brightline has already been able to provide valuable insights into San Francisco air quality trends for a range of other stakeholders including ten city agencies that have collaborated with the air quality monitoring program to date. City agencies are interested in more granular air pollution data and how it can help map out the air quality impacts of things like zoning policies. For example, when they're approving development projects they want to be able to measure air quality impacts from construction.

The air quality monitoring network is now managed through an ongoing partnership between Brightline and two other nonprofits, Community Youth Center of San Francisco (CYC) and CCSROC. CYC works to develop educational opportunities for youth across San Francisco, while CCSROC directs community organizing among tenants of SRO buildings in San Francisco.


The air quality monitoring network provides a unique opportunity for Brightline to engage with other community groups through a program that fosters local leadership and empowers community members to act on the issues facing their neighborhoods. With CYC we're building an Environmental Leadership program, where students can volunteer to analyze data from the network and share findings with the community. The CCSROC has a tenant empowerment program where representatives of each building act as leaders that convene to talk about the issues that have been facing their buildings and populations. The air quality monitoring network has provided this forum with data to support their conversations.” 

- Eddie Ahn, Executive Director of Brightline Defense

The air quality monitoring program will connect these community groups to several regional and local government agencies and open a long-needed line of communication about how air quality impacts local communities. The agencies involved include the Bay Area Air Quality Management District (BAAQMD), SF Municipal Transportation Agency (SFMTA), SF Department of Public Health, SF Planning Department, and SF Department of Environment, among others. 

Ahn shows a Clarity Node-S air quality monitor to media during an interview about the new community monitoring network.

Through the Environmental Leadership program, Brightline will be graduating eight leaders representing different high schools across San Francisco each year. And of the forty individuals involved with the CCSROC Tenant Leadership Program, Brightline works directly with fifteen of them on air quality issues. 

With student and tenant leaders in place to act as community organizers, Brightline was able to ramp up community outreach around the air quality monitoring program. Brightline engaged a Stanford University class to design promotional materials for the network, and community organizers put up 500 posters across impacted neighborhoods in San Francisco to raise awareness. These Brightline Air Quality Fellows also put together an "Introduction to Air Quality" guide that was published in early 2021 to help community members interpret data from the air quality monitoring network, as covered by the CARB environmental justice blog.

Clarity was also involved with getting the word out about the network, making team members available to participate in guest talks, and educate community organizers to make sure they understood how to use the Dashboard. 

Clarity has always been very accessible to make sure all of the different pieces of this program - technical and nontechnical - were able to move forward. There is a lot of value in working with an air quality monitoring service provider that acts as a partner rather than a vendor.” 

- Eddie Ahn, Executive Director of Brightline Defense
Sustainable Cities, a community-engaged learning course offered through the Program on Urban Studies and Earth Systems Program at Stanford University, taught by Professor Deland Chan.

Through ongoing outreach, each student community organizer is expected to reach about five hundred different businesses and households to talk about air quality and inform stakeholders about the new monitoring network. The tenant leaders will reach an additional thousand SRO tenants each - adding up to a population in the thousands. Outreach includes activities like flyering, surveying residents to learn more about their air quality issues and concerns, and raising awareness about the air quality data map that is now available via Clarity’s OpenMap. 

Moving from data to action with quarterly data reports

Collecting accurate and local data is an important first step toward improving air quality, but the real work is in moving from data to action. Capturing the data required to make the invisible, visible, serves to illustrate a narrative that many residents are experiencing but had previously been largely undocumented. But for that narrative to come to life and affect positive change requires sustained collaboration among the San Francisco communities and government partners to determine an action plan to rewrite this narrative and improve air quality.

That narrative is beginning to take shape - over the first three months, data from Brightline’s air quality monitoring network has demonstrated that certain neighborhoods are especially vulnerable to wildfires. These neighborhoods had the highest average daily AQI during the 2020 wildfire season. Future reports will delve deeper into an evaluation of hourly AQI trends to identify air pollution spikes related to specific emission sources such as construction, commuter traffic, and emergency diesel generators.

A Clarity Node-S installed on a street lamp to monitor particular matter air pollution near a construction site in San Fran

Brightline is also working with the Bay Area Air Quality Management District (BAAQMD) to co-locate an additional sensor with a government air monitoring station in San Francisco, which will provide improved calibration capabilities for data accuracy. 

Brightline is just getting started with this network, but it is already making an impact on diverse groups across San Francisco. We look forward to seeing how Brightline and their air quality monitoring partners can leverage their Clarity network to improve air quality in the city of San Francisco. 

We asked Eddie if he has any tips for other community groups looking to implement an air quality monitoring network

It takes a lot of research, preparation, and conversation with the communities you serve to effectively plan and deploy an air quality monitoring program. If you're starting with air quality monitoring, I would recommend you take the following steps: 

1. Ask yourself what problems you are trying to solve. What are the key issues? 

2. Find a good technical partner like Clarity to help think through how you're going to track those issues.

3. Ultimately, think through the policies you would like to change and try to project how long you think it will take to achieve policy change for the better? Will it be six months to two years down the line?”

What’s next for Brightline Defense? 

After successfully mobilizing an outdoor air quality monitoring network for San Francisco, Brightline is now looking to indoor air quality projects as its next challenge. SRO hotels are aging buildings that sorely need retrofitting with modern filtration to protect against poor outdoor air quality. Keep an eye out for more groundbreaking air quality work from Brightline in the coming years!