LOS ANGELES _ Despite growing warnings about the health problems tied to traffic pollution, Los Angeles officials continue to approve a surge in residential development along freeways. And the crux of their effort to protect people's lungs is a requirement that developers install air filters.
But even the highest-quality filters capture only some of the dangerous ingredients of car and truck exhaust, and to be effective, experts say, they must be frequently replaced and the building's ventilation system must run virtually full time with all doors and windows closed.
The city inspects new projects' air-filtration systems, but the head of the Department of Building and Safety concedes that his office has no procedures for documenting whether the proper filters were installed and does not conduct follow-up inspections to ensure that they're being maintained and replaced.
Air-quality regulators and health experts warn that relying on air filtration and other mitigation measures will not solve the health threat to residents moving into new homes along freeways _ Southern California's biggest conduits of pollution.
They have for more than a decade urged cities to stop permitting new housing within 500 feet of heavy traffic to protect residents from asthma, cancer, heart attacks, preterm births and an array of other health problems that studies have associated with living close to major roadways.
Yet, Los Angeles in 2015 issued building permits for 4,300 homes close enough to freeways to threaten occupants' health _ more than in any year over the last decade. Since then the city has permitted more than 3,000 additional units within the 1,000-foot distance where the city advises developers that residents are at risk from air pollution, with at least one just 60 feet from freeway traffic.
Mayor Eric Garcetti and other local politicians have opposed limits on how many homes can be built near freeways on the grounds that it would hamper efforts to ease Los Angeles' severe housing shortage.
Builders agree, noting that additional restrictions on new construction will increase the cost of housing. "And we have a very, very high need for housing," said Tim Piasky, who heads the Building Industry Association Los Angeles/Ventura Chapter.
Environmental advocates and neighborhood groups, meanwhile, call for stricter development standards and freeway buffer zones to protect residents' health.
Doug Haines of the East Hollywood Neighborhood Council told City Council members at a recent hearing that fine particulates will damage the lungs of children in hundreds of new housing units proposed along the 101 Freeway.
"It passes through door jambs and window frames. There is no realistic way to filter it," Haines said. "The only way to stop this is to limit all construction next to freeways."
Researchers have for years studied how to protect the health of people living near traffic pollution.
In a report released in April, the California Air Resources Board reviewed more than a decade of scientific studies and highlighted what it said are "promising strategies" to help decrease pollution exposure for residents close to freeways when cities do not heed its warning against building homes within 500 feet.
Among the solutions endorsed by the agency are sound walls, vegetation barriers and "buildings with varying shapes and heights" to help disperse traffic pollutants.
"It's basically giving people a second set of solutions to the problem," said Bart Croes, research division chief at the Air Resources Board.
High-efficiency air filters are among the most effective tools, but neither the Air Resources Board nor most air-quality experts consider them an adequate fix.
"Filtering the air for particles is better than nothing," said Scott Fruin, a professor of preventive medicine at USC's Keck School of Medicine. But he's skeptical of cities that believe filters are an adequate solution. Studies show, for example, that high-quality air filters can capture some of the harmful particles in traffic emissions, but do not keep out toxic exhaust gases.
"The carbon monoxide, the volatile organics, benzene or 1,3-Butadiene, they're going to be too high, and the filtration won't take care of that," Fruin said.
Air-quality officials have also advised cities that the benefits of filters are significantly undermined if the building's heating, ventilation and air conditioning system isn't running at all times with all doors and windows closed.
UCLA doctoral student Amelia Mueller-Williams said that even though she tries to keep the windows of her student housing apartment near the 405 closed, she still finds black dust in tissues when she blows her nose.
"Our home is polluted in every sense of the word," she said.
And such housing keeps getting approved.
In 2013, over the objections of air-quality regulators, the Los Angeles City Council unanimously approved developer M. David Paul's 325-unit Il Villaggio Toscano project in Sherman Oaks right next to the 405-101 interchange. The city required only that the apartments have high-efficiency air filters and that certain windows facing the freeway can't be opened.
Attorney Robert P. Silverstein, who sued the city, challenging its approval of the project on behalf of a neighborhood group, called such restrictions "a joke."
"There's a reason they call these kinds of apartments 'black lung lofts,'" said Silverstein. "Some of these units are mere feet away from the busiest freeway intersection in the country."
Rick Coca, a spokesman for Councilman Jose Huizar, who chairs the city's Planning and Land Use Management committee, said Huizar voted for the Il Villaggio Toscano development because it had the support of the local council member at the time, Tom LaBonge.
Former Councilman LaBonge said he voted for the project because it had the support of the planning department, was located on an empty parcel next to the Sherman Oaks Galleria mall and would help satisfy "the need for housing."
