Community-led efforts to monitor air quality in Bayview, Eastern neighborhoods gain traction

San Francisco community groups are working to install high-quality sensors in the Bayview Hunters Point and other neighborhoods in an...

San Francisco community groups are working to install high-quality sensors in the Bayview Hunters Point and other neighborhoods in an effort to independently monitor air pollution and provide residents with publicly accessible, real-time data.

Air pollution in San Francisco and the greater Bay Area is monitored by the Bay Area Air Quality Management District, which operates a pricey but highly accurate sensor at one San Francisco location along standards set by the Environmental Protection Agency. However, the groups say there is a need for hyperlocal air monitoring on a neighborhood-by-neighborhood level to detect disparities and support community specific remediation efforts.

Urban planner Rebecca Skinner and electronics engineer Ken McGary this summer launched San Francisco AQ, an air quality project that aims to collect hyperlocalized measurements of particulate matter — microscopic solid and liquid droplets in the air that can be harmful if inhaled — by installing coffee-cup sized sensors outside of some two dozen homes in the Eastern neighborhoods, where environmental and health disparities persist.

“We want to create a public facing environmental data infrastructure that does not exist now — we want it to be a part of The City’s public infrastructure, with data that you can look up on a website through your computer or smartphone,” said Skinner.

“Hyperlocal data for the Eastern neighborhoods will make any connections that may well exist between high particulate levels and consequent severe, cumulative illness, evident,” she added, describing her project as aggregating “useful data for epidemiological and public health studies.”

Each sensor, called “Purple Air,” costs about $200. So far, seven have been deployed, with more than half located in the Bayview Hunters Point. The predominantly African American community suffers from higher rates of chronic obstructive pulmonary disease hospitalizations and asthma than in other communities.

Later this year, Greenaction for Health and Environmental Justice, in partnership with a number of Bayview community groups, will launch a separate effort to install 10 Dylos air monitors in the Bayview with funding from the California Environmental Resources Board, according to Greenaction Executive Director Bradley Angel. The groups are currently training youth on how to conduct air monitoring and community engagement.

For decades, the Bayview has been at the heart of community-led environmental justice campaigns. The neighborhood is intersected by two major highways and houses a landfill, a wholesale produce market that draws numerous trucks each day, a sewage treatment plant, a recycling center, and was once home to a PG&E power plant.

Residents have also long expressed concerns about ongoing radioactive remediation at the decommissioned Hunters Point naval shipyard and large scale housing construction.

“It’s really exciting that there are finally resources coming into the community that are being directed to the groups on the ground, for the community to address long standing pollution and health disparities,” said Angel, who added that members of the Bayview community suffer from a “wide range of respiratory and heart problems, high asthma rates, and so many pollution sources.”

“There are a lot of issues and our hope is that through community knowledge and community led air monitoring over the next few years, we will have more information to force the government to finally stop the pollution of Bayview Hunters Point,” he said.

In 2016, Skinner and McGary applied for a grant with the Supplemental Environmental Projects to collect air quality data locally and develop digital applications for presentation, a field that they indicated is somewhat in its infancy.

In the backyard of McGary’s Excelsior District home on Thursday, the pair demonstrated the equipment used to calibrate the sensors.

McGary explained that while the Air District’s San Francisco sensor is “very accurate,” it does not capture all sources of air pollution and reports on an hourly basis, not in real-time.

“If there are a whole bunch of trucks that come through a certain area but only last five minutes, there’s a big spike in pollution that gets lost in the shuffle. So you don’t really know that you might have a problem with truck emissions,” said McGary. “Ideally you’d want as many monitoring points as you can have. That’s called spatial density.”

In addition to the purple air sensors, Skinner and McGary will also install more elaborate pollution and wind sensors at three sites that will work as reference sensors to the Purple Air sensors. these also measure concentrations of Volatile Organic Compounds.

The pair plans to attach WIFI-powered smart bulbs to the sensors that change color in accordance to real-time air pollution levels. The bulbs will sync with the color scheme of the Air quality index set by the EPA, with green indicating “good” levels and magenta indicating “very unhealthy levels.”

Skinner and McGary said that the bulbs are meant to alert residents who volunteer to host the sensors as well as their neighborswhen airborne particles reach dangerous levels. They noted that many San Franciscans became familiar with the EPA Air Quality Index and corresponding colors during last year’s Northern California wildfires, which blanketed The City in smoke.

“A light bulb with a color is easy to understand. Tot everyone reads and not everyone speaks English, but at this point millions of people know the color coding for air quality and we want everyone to have access to this,” she said.

Purple Air sensors are deployed on a voluntary basis. Bayview resident Chris Whipple was the project first’s volunteer.

“We have a young son and we are concerned about the environment that he’s growing up in,” Whipple told the San Francisco Examiner.

Whipple said that his partner, who has lived in the Bayview for some three decades, recently suffered an asthma attack that landed her in the hospital.

“It was scary,” said Whipple. “Why isn’t The City putting up air quality monitors at every bus stop? Why does this have to be a citizen initiative? …the government should ultimately be taking care of our health needs.”

Whipple said that he volunteered for the project because he hopes that it will result in “some policy changes.”

“I wish the government would invest in infrastructure that would help them build the data they need to form better policies,” he said.

According to the Air District’s air monitoring officer, Eric Stevenson, the air district this year has also begun performing “hyperlocalized measurements throughout the Bay Area.”

“That data gives us the opportunity to see differences in concentrations that vary from neighborhood to neighborhood that may not be as well represented by the monitoring stations that are out there as part of EPA requirements,” said Stevenson.

“Those local trends may be different than the regional trends. That’s the whole purpose of trying to get at this hyperlocal scale — so we can concentrate our resources on removing disparities from location to location as far as air quality goes,” he said.

For more information on the San Francisco AQ project or to view data collected on particulate matter pollution, visit

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