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On Oct. 13, 2017, during the North Bay fires, cars slow during rush hour traffic on Highway 280 in Cupertino. Haze from the fires is visible in the air.  Isha Salian/Peninsula Press
On Oct. 13, 2017, during the North Bay fires, cars slow during rush hour traffic on Highway 280 in Cupertino. Haze from the fires is visible in the air.  (Isha Salian/Peninsula Press)

California Tackles Air Pollution Disparities With Data, Policy Efforts

California Tackles Air Pollution Disparities With Data, Policy Efforts

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As the North Bay fires burned more than 100,000 acres over the course of a few weeks last October, 100 miles south, in Santa Clara, Sutter Health pediatrician Manisha Panchal was stunned at the number of patients coming to her with coughs and bronchospasms — even children who had never wheezed before.

During the fires, the entire Bay Area got a taste of what it’s like to walk around during a high pollution day in Beijing, China. The fires released as much pollution into the air as a full year of cars on California roads.

But on a typical day, air quality is not top of mind for most locals.

“It comes out when there’s the wildfires,” said Panchal, “and then it goes away, and people forget.”

As climate change continues, wildfires could become the “new normal” for California, Gov. Jerry Brown warned last year. Despite the strides California policymakers have made to reduce emissions, this natural phenomenon will contribute to climate change and short-term air pollution. However, it’s not the only concern state officials have about air quality.


While California holds a reputation as a leader in environmental policy, it still ranks worst out of all 50 states for average public exposure to particulate matter pollution — tiny particles measured in microns, a millionth of a meter — largely due to the state’s topography and population density. California is also home to seven of the 10 U.S. metropolitan areas with the highest short-term levels of particle pollution. In 2018, the Bay Area ranked sixth on the list, above the notoriously polluted Los Angeles-Long Beach area.

And though overall air quality statewide is improving, there are communities where pollution levels are the same or worse, University of Southern California lung health expert Ed Avol said. Startups and local air districts are working to reduce this disparity in the air people breathe, but they face several challenges to do so.

Understanding air quality at a hyperlocal level is a problem for both local residents and public officials. Data monitoring stations are spaced far apart, taking regional air measurements that differ drastically from what an individual may be actually breathing at any given time. As population and traffic congestion in the Bay Area grow, existing infrastructure keeps many local schools and athletic facilities a stone’s throw from emissions-heavy freeway routes. And as has been well-documented, low-income areas and communities of color face stronger impacts from polluted air.

“They get overexposed because we can afford to live in a more desirable place, and this becomes an issue of environmental justice, environmental racism,” said Avol.

To be sure, air quality in many areas around the world is far worse than it is in the Bay Area. Cities like Beijing and New Delhi rank far higher in pollution measures on a daily basis. But the issue is worth working on locally because today’s levels still produce negative health effects, researchers say, particularly for disadvantaged populations.

Filling in the Data Gap

On an average day, a Bay Area resident who looks at the Environmental Protection Agency’s AirNow air quality website sees nothing to be concerned about. However, startups taking a closer look find pollution can vary greatly from neighborhood to neighborhood.

San Francisco-based Aclima is a startup that says it’s “filling in the pixels” on air pollution data by collecting street-level measurements. Aclima works with companies like Google and researchers and public agencies like the EPA to measure air quality. The company drove two Google Street View cars, mounted with an air monitoring sensor the size of two shoeboxes, more than 100,000 miles across California. The sensors collected a billion data points over two years, according to vice president of communications Kim Hunter.

Air monitoring equipment set up on a roof.
Sensors on the roof of the Bay Area air district’s San Pablo monitoring station connect to equipment in a laboratory below. (Isha Salian/Peninsula Press)

The company’s street-by-street visualization of Oakland shows hot spots of pollutants near the Port of Oakland, as well as on Interstate 880 and other major roads. Pollution can increase by five to eight times from one end of a block to another, said the company’s chief scientist Melissa Lunden.

These variations can depend on factors less obvious than proximity to roadways or factories. Subtle features can make a difference, like wind patterns, the presence of trees between roads and residences and whether freeways are at ground level or elevated. Aclima says its granular data could help buildings and cities make informed decisions about emissions exposure.

Recent advances in sensor technology allow startups to develop cheaper, portable devices that could allow monitoring agencies to expand their data collection, said Lunden. The sensor Aclima is developing costs “100 to 1,000” times less than the equipment currently used by researchers and officials.

Installing a full Bay Area Air Quality Management District monitoring station costs around $250,000 and require more than half a full-time employee’s work hours to operate, said Eric Stevenson, the district's director of meteorology and measurements. Since it’s such a large investment, he said the district sites most stations to represent very large geographical areas.

The district currently runs 33 air monitoring stations in the region to measure ambient air quality for that area. Just four of the seven stations between Redwood City and Gilroy measure particulate matter.

A line chart of particulate matter in Redwood City
A line graph showing the reduction in particulate matter pollution in Redwood City between 1998 and 2012. The median PM 2.5 reading in 1998 was 20 micrograms per cubic meter. In 2012, it was down to 6. Data from the Environmental Protection Agency’s Air Quality System Data Mart. (Isha Salian/Peninsula Press)

“I think it’s a failing of the air districts, and the state government, which doesn’t require the air districts to do more,” said Bill Magavern, policy director at the Coalition for Clean Air.

Magavern says the air monitoring network does what’s required to comply with EPA rules about pollutant reporting, but this level of monitoring does not capture important neighborhood-level data.

His coalition has begun a project to install cheaper, portable monitors at schools and residences in the Los Angeles area. Once communities and government officials have a better understanding of hyperlocal air data, they can begin taking action to mitigate pollution.

California is now making strides to collect this kind of data on more narrow pockets of the state.

The aim: for all residents to be breathing the same quality air.

Getting Down to the Neighborhood Level

Growing up in Bell Gardens, a city in Los Angeles County, state Assemblywoman Cristina Garcia saw truck and freight traffic from the Port of Long Beach go by every day, spewing pollution into the air. Six freeways and a rail yard “choke my community,” she said.

Garcia noticed that districts like hers — working-class areas, communities of color, were often located in regions with poorer air quality. This experience prompted Garcia to take up the cause of environmental justice as a state legislator.

“My community has been treated like a wasteland,” she said. Garcia always heard that as the environment of California improved overall, her district would catch up, too. But she wasn’t seeing the results: “We’ve been calling it trickle-down environmentalism for a few years now.”

So Garcia proposed Assembly Bill 617, a regulation that mandates local air districts identify disadvantaged communities in each region for closer monitoring. The districts must then implement action plans to decrease pollution in those specific areas.

The bill passed last year, and local air districts had to submit a draft description of the first target communities by April 30. Garcia said she expects some positive results in air quality by 2023.

For now, the Bay Area air district is looking primarily at West Oakland as a site for action plans to reduce emissions, and at Richmond as a site for additional air monitoring. The Port of Oakland and highway traffic are major emitters for the region.

“The important thing is that we protect the health of every resident of the Bay Area,” Stevenson said. “No one else is doing this — no one else in the country.”

A woman marking up a map for air monitoring.
At an air district event, Point Richmond resident Lori Goldwin marks a potential site for community air monitoring. (Isha Salian/Peninsula Press)

On a recent Wednesday night in Richmond, around 60 community members gathered to discuss the air district’s plans for additional air monitoring in the city. The air district responded to community concerns about whether monitoring data would be easily accessible online, and that the data would lead to action.

“These are human rights violations when you’re talking about disproportionate impact,” Henry Clark, executive director of the advocacy group West County Toxics Coalition, at the meeting.

In an effort to include local residents in the monitoring process, the air district asked attendees to suggest potential sites for placing new air monitors. They could out fill a form online, or place a neon sticker on a large map of Richmond pinned to the wall.

“I put a dot where I live at the top of the hill,” said attendee Lori Goldwin, a resident of Point Richmond. In the past six months, she’s started to notice odors from polluted air in her neighborhood.

“Maybe I’ll be run out of town by this,” she said. “I don’t want to move, but I could move.”

Rethinking School Design

Children are more vulnerable to irritation from traffic and air pollution because their lungs are still developing, said Avol. And while children are exposed to air pollution at home, another major factor is the location of their schools. California Air Resources Board lung researcher Barbara Weller said even in Bay Area, where overall pollution is fairly low, having schools near traffic is associated with increased wheeze in children.

These schools are more prevalent in disadvantaged communities. Statewide, 58.7 percent of students were eligible for free or reduced-price school lunches during the 2014-2015 school year. For schools located within 500 feet of major roads, that figure jumps to 67.2 percent.

A 2003 California guideline recommends that no new schools should be built within 500 feet of a major road or freeway. But while “it’s wonderful that new schools are sited away from traffic ... a lot of schools were already built,” Weller said. California has more than 1,000 active public schools located within 500 feet of major roads – a third of which opened in 2004 or later, an analysis of data collected by the Center for Public Integrity shows.

Dr. Panchal’s children attend one of those schools – Bullis Charter School in Los Altos, opened in 2004. She says the lunch tables are located right next to San Antonio Road, separated by a fence. “Why would they put the tables there?” she said. “For that one hour the kids are just breathing these particles.”

A Google map of Cupertino Middle School and Homestead High School and its location a few hundred feet away from the freeway.
Cupertino Middle School (upper left) is located within 500 feet of Highway 85. Neighboring Homestead High School’s playing fields directly border Interstate 280. The average annual daily vehicles on the interstate in Sunnyvale jumped from 85,000 in 1993 to 120,000 in 2016. (Isha Salian/Peninsula Press)

The air resources board says the layout of the campus makes a difference for students’ exposure levels to polluted air. Weller recommends moving playgrounds, fields and other outdoor areas further from roads as a solution to lessen the health impacts of vehicle emissions. Parking lots or enclosed areas could border the road instead, Avol said.


“We should not be thinking, ‘If we get to this one level everything will be fine,’” said Avol. “There is no threshold, there is no safe line.”

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