Data

Pollution Data Map Plots Hardest-Hit San Francisco Neighborhoods

A new data map shows which neighborhoods in San Francisco are the most impacted by pollution.

by Rachel Swan, San Francisco Chronicle / September 5, 2017
San Francisco (Shutterstock)

(TNS) — Black dust cakes the poplar trees in South Park, the San Francisco waterfront neighborhood at the western end of the Bay Bridge.

The soot piles up on stairwells and speckles window blinds. It stains the surfaces of magnolia branches. It covers the leaves that fall into nearby Alice Street Community Gardens, where low-income seniors tend vegetable plots.

“For a while, I was collecting it in a container with the intent of presenting it to the Board of Supervisors,” said Alice Rogers, a retired graphic designer who bought a condominium on South Park Street in 1993.

A few years ago, Rogers discovered that her gentrifying neighborhood is among the most polluted in the city. SoMa is the locus of San Francisco’s building boom, so people are pouring in and cars are jamming the streets, many of which funnel traffic to and from the Bay Bridge.

Asthma-related emergency room visits

Reported cases for every 10,000 people between 2013 and 2015 show big differences based on neighborhood proximity to freeways:

93 Bayview

74 South of Market

12 West Portal

The most recent figures available from the Bay Area Air Quality Management District — a map based on 2010 data — show that air pollution runs along the city’s highways, and Interstate 80 cuts straight through SoMa, South Park, South Beach and the city’s new high-rise neighborhood, Rincon Hill. The map also shows that even before the construction spree of the past few years, parts of SoMa had particulate matter concentrations higher than San Francisco’s safety threshold of 10 micrograms per cubic meter of air.

Some residents wonder what, if anything, can be done.

“Congestion, that’s our No. 1 issue,” said Katy Liddell, president of the South Beach/Rincon/Mission Bay Neighborhood Association. “We are ground zero for people coming and leaving the city, and now we have all these idling cars and trucks trying to get onto the bridge.”

Data from the Metropolitan Transportation Commission corroborates what Liddell and others see when they look out their apartment windows. Congestion — defined as traffic flowing below 35 miles per hour on the city’s freeways — increased from 3.8 percent of the time in 2010 to 5.7 percent in 2015.

And figures from the traffic analytics firm Inrix show travel times on the Bay Bridge went up significantly between 2014 and 2017, with the largest increase being westbound trips on Interstate 80 at 1 p.m., which now take 6.4 minutes longer than they did three years ago. Thirty-nine percent of drivers heading westbound into San Francisco end their trip in SoMa.

More people, more cars, more pollution

79%

Increase in population for the ZIP codes that include Rincon Hill, South Beach and Mission Bay, according to census numbers for 2000 and 2015

As traffic has increased, so has population: Between 2000 and 2015 the number of people living in the ZIP codes that include Rincon Hill, South Beach and Mission Bay nearly doubled, from 19,426 to 34,749, according to U.S. Census figures.

Despite that bump, residents say the city hasn’t provided enough new public transit to accommodate the ballooning population.

“People think of our area as transit-centric, but it’s not,” said Rincon Hill resident Jamie Whitaker, who complained there aren’t enough Muni buses running along the Embarcadero. He fears new projects like the Warriors’ Chase Arena in Mission Bay and the California Pacific Medical Center on Van Ness Avenue will encourage more people to drive into the city — many of them straight through his neighborhood.

The question is whether the air has gotten dirtier or whether dirty air is merely affecting more people. Virginia Lau, an advanced project adviser for the air quality district, noted that consumers have shifted to buying hybrids and fuel efficient cars, which emit fewer particulates. But even if air quality has improved overall, neighborhoods around freeways still get the most pollution, she conceded. And it’s especially bad near heavily congested roadways like the Bay Bridge, where constant braking and idling causes bits of tire and brake pads to erode and drift into the atmosphere.

“While the (city’s) overall air quality can improve, that doesn’t preclude there being a disproportionate burden on certain neighborhoods,” said Karen Cohn, who manages the Children’s Environmental Health Promotion Program for the city’s Department of Public Health.

City officials are taking incremental steps to help.

In 2008, San Francisco enacted a law requiring ventilation systems and filters in new residential buildings, child care centers and private schools, which affected a lot of the projects being built South of Market. And in 2015, it mandated that contractors use cleaner equipment in the city’s most polluted areas, which also include parts of the Bayview, isolated areas around Fisherman’s Wharf and along Highway 101 through Potrero Hill and Visitacion Valley.

The city has also shifted away from diesel and toward more fuel-efficient vehicles: The Third Street Light Rail replaced several diesel bus routes, and Caltrain is expected to run on electricity instead of diesel by 2023.

Public health officials are working on a new Community Risk Reduction Plan to protect residents from the harmful effects of air pollution. The plan, which they expect to roll out next year, will include a new map highlighting areas that are most exposed to lung-damaging particulates.

The idea is to inspire new policies to protect people in the most polluted areas, and then try to shrink those areas over time, said city environmental planner Josh Pollak. He wasn’t sure what sorts of policies would emerge from the process.

Liddell and Rogers are both working with the city on the new risk reduction plan, but Rogers is wary.

“Politically, there’s no low-hanging fruit, and this is not going to be easy to fix,” she said. Rogers noted that it may take something radical, like congestion pricing — adding tolls on busy roadways and using the money to fund public transit — to solve the problem.

Before the eastern waterfront became a hotbed of development, air pollution mostly affected San Francisco’s lower-income neighborhoods to the south. In past decades, the main sources of contaminants were the PG&E’s Hunters Point power plant, which was shuttered in 2006, and the Potrero Generating Station, which closed in 2011.

Statistics from the California Office of Statewide Health Planning and Development show that between 2013 and 2015, the Bayview — which is surrounded by freeways, cement plants and other industry — had 93 asthma emergency room visits for every 10,000 people. South of Market had 74 visits. West Portal, which is on the other side of the city and relatively insulated from freeways and major streets, had significantly fewer visits — about 12 for every 10,000 people.

“The health equity concerns that impacted low-income communities for a long time are now impacting the upper-income communities that we’re building around the freeway,” said Supervisor Jane Kim, who represents SoMa and lives two blocks from I-80.

Kim supports aggressive measures to reduce the number of cars on the road — like adding carpool lanes on Highway 101 or collecting tolls in the city’s most congested areas. Such measures would have to be imposed by the state and would likely stir controversy in SoMa. But they could protect residents from pollutants, Kim said.

“One woman wrote to me from a condo in Rincon Hill and asked if it was safe to raise children here,” Kim said. “That was heartbreaking.”

 

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