Companies like Purple Air and IQAir, with air pollution sensors that cost under $300, have brought air quality monitoring to the masses. But when Lawrence Berkeley National Laboratory (Berkeley Lab) scientist Tom Kirchstetter looked at Purple Air’s map last year during wildfire season, he noticed a big hole in Richmond, a city of 110,000 to the north of Berkeley.
“You can see what appears to be hundreds of the sensors in Berkeley and Marin County, for example,” said Kirchstetter, director of Berkeley Lab’s Energy Analysis & Environmental Impacts Division. “In contrast, there were very few sensors in Richmond. Whether there were cost barriers or maybe lack of awareness, I’m not sure, but unfortunately it really showed that even with these low-cost sensors, which make air pollution exposure more personal, there’s still inequity in their adoption.”
To address that gap, Berkeley Lab scientists are teaming with Oakland-based nonprofit Physicians, Scientists and Engineers (PSE) for Healthy Energy to install sensors that will give residents data to understand air pollution sources and patterns. The project is supported by a grant from the California Air Resources Board under a program created by AB 617, a law passed in 2017 to establish a community-based framework to improve air quality and reduce exposure to toxic air pollutants in communities most impacted by air pollution.
Air quality in the city of Richmond, located on the San Francisco Bay, is impacted by freight activity, port operations, an oil refinery, and a nearby freeway. The population is predominantly people of color, and the city includes census tracts that have been designated as disadvantaged communities.
Traditional air quality monitoring involves the local regulatory agency installing expensive analyzers at usually only one location within a city like Richmond. “That one community monitoring station can be very informative for the purposes of understanding long-term regional trends and whether an area is compliant with national standards,” Kirchstetter said.
“But as we know, the amount of some pollutants varies a lot over short distances. Many communities are concerned with things that are very local, such as, locomotives carrying coal and emitting soot or coal dust, refineries emitting volatile organic compounds, or trucks driving through or adjacent to their neighborhoods to access ports or distribution centers,” added Rebecca Sugrue, a UC Berkeley PhD candidate, who is leading the black carbon monitoring effort in Richmond.
Working with PSE, the Berkeley Lab team installed 50 low-cost air pollution sensors at businesses, residences, and schools throughout Richmond and San Pablo. The PSE sensors monitor for ozone, fine particulate matter (PM2.5), and nitrogen dioxide (NO2). “Berkeley Lab’s sensors monitor for black carbon, which is a primary component of diesel particulate matter,” said Chelsea Preble, a research scientist at UC Berkeley and Berkeley Lab who has also done research with the black carbon monitors. “This was a good opportunity for us to leverage a device developed at the Lab for a similar project in West Oakland four years ago.”
“Diesel engines emit diesel particulate matter, which is considered to be a toxic air contaminant and is a primary air pollutant, but it’s only a small portion of ambient particulate matter. If you’re measuring just particulate matter, you’re not really getting a good signal for the local air pollution from truck activity in your community,” Kirchstetter said. “Black carbon is much more specific to diesel engine activity in the communities, which is why it’s a nice addition to this community air monitoring program.”
Data was collected for a month last year during wildfire season, a month in winter, and now for a month in the summer. “The meteorology changes a lot here between winter and summer, such that air pollution concentrations change a lot,” Sugrue noted.
The data generated will power an online map of black carbon concentrations in Richmond, similar to the online Purple Air map. “My goal is to create this open-source resource for the community that is accessible and data-driven, to add to the information that communities need to advocate for policies to reduce emissions,” said Sugrue.
The Berkeley Lab researchers stress that working with the community has been key. “I’m really happy that the community groups are the ones that are able to tell you the local knowledge, and that they are involved in the process,” said James Butler, another UC Berkeley graduate student on the team. “It’s important to realize that you’re there to help the community and that it’s not the other way around. This data is really meant to serve them. It’s science for the betterment of society.”