The City's most happening hood is also its least healthy.
And only one thing can save residents of the Mission district from breathing San Francisco's dirtiest air: going green, and going greener in 2014 than in the past year.
Nearly all San Franciscans live within 1.5 miles of a major freeway, according to a recently released study from the Massachusetts Institute of Technology. The resulting exposure to particulate matter makes lung ailments like cancer and chronic obstructive pulmonary disease (COPD) two of the most common health problems in The City.
But despite being bracketed in by two busy freeways -- Interstate 280 and U.S. Highway 101 - places like the Outer Mission aren't The City's least-healthy neighborhoods. In fact, the air is cleaner at Mission Street and Geneva Avenue than it is at Mission and 24th streets.
Mission district proper has the poorest health of any San Francisco neighborhood, according to the MIT report "Health and Urbanism." A key reason is open space - as in less of it.
In places like the Outer Mission, homes have backyards that abut one another. That makes for 10 times the green area and three times the amount of street trees than in the development-happy, denser Mission. Trees and "permeable open space" make the air more breathable and less unhealthy, the report found.
The City has set ambitious goals for reducing greenhouse gas emissions, despite a rising population and increased electricity use. But there's not much any city department can do to move big rigs and shuttle buses off freeways - or move the freeways somewhere less populated.
And more than 25 percent of San Francisco's surface is paved streets and sidewalks, a greater land area than all of The City's parks, according to the Department of Public Works. That means the area isn't about to become permeable anytime soon.
Luckily, planting trees and putting in shrubs are exactly how The City can best clear the air, the MIT researchers found. That happened last year, but environment watchers want more in 2014.
In 2013, DPW issued 228 permits for property owners to tear up concrete sidewalks in favor of green space, according to Mindy Linetzky, a department spokeswoman.
The City also added to its stock of 105,000 street trees another 1,200 or so, while also lining Great Highway with 11,000 shrubs and planting drought-resistant plants between Wawona Street and Lincoln Way on 19th Avenue, Linetzky added.
When city employees travel, The City collects a "pollution fee" that goes into a pot of money called the Carbon Fund. Last year, the Carbon Fund doled out $200,000 for neighborhood-level greening projects, according to the Department of the Environment. But none of that went to groups in the Mission, some of which found the application process too difficult to navigate, according to Joshua Arce, who chairs The City's Environment Commission.
"That's not going to happen next time around," he said.
The City reduced its carbon footprint to 14.5 percent of 1990 levels, Mayor Ed Lee said in August, which is admirable but short of The City's stated goal of 20 percent reduction by 2012.
San Francisco could always do more to encourage more green space: The MIT scholars suggested providing private property owners a tax credit to turn their roofs green.