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Are We There Yet? The Air Pollution Threat

Editor's Note: Living near freeways and major traffic thoroughfares is hazardous to your health. This week's excerpt from Are We There Yet? reviews the impact this air pollution continues to have on pregnant women and children.

Public-health advocates have also focused on the transportation and land-use planning arena because they are concerned about the threat posed by transportation-related air pollution. According to the Environmental Protection Agency (EPA), mobile sources of air pollution — cars, trucks, trains, planes — are the largest contributor of air toxics, including more than half the carbon monoxide, over a third of the nitrogen oxides, and almost a quarter of the hydrocarbons. “Particulate matter,” a catchall phrase often used to describe a number of pollutants, has been identified as a major cause of ill health, especially among children.

More than 2,000 peer-reviewed studies have been published since 1996, the last time that the EPA reviewed the standards for particle pollution. The new studies validate earlier research showing strong relationships between particulate pollution and illness, hospitalization and premature death. And they suggest that the health effects are more far-reaching than was previously believed.

Many of these studies have shown that children living next to highways are more likely to develop respiratory problems such as asthma, and to have a reduced life expectancy. University of Southern California researchers published a report in the New England Journal of Medicine in 2004 that found higher rates of decreased lung function, coughing and bronchitis in children living in more polluted areas. A follow-up study in 2005 expressly linked living near freeways to higher levels of nitrogen dioxide, and showed that children living near freeways were more likely to have asthma.

The evidence that poor air quality has on health keeps piling up. A group of researchers, including Rochelle Green from EPA, found in a 2009 study that pregnant African-American women who live within a half mile of freeways and busy roads were three times more likely to have miscarriages than women who don’t regularly breathe exhaust fumes. Dr. Joan Denton, director of the Office of Environmental Health Hazard Assessment at the California Environmental Protection Agency, says: “This study adds weight to the growing body of evidence that constant, heavy exposure to traffic exhaust significantly increases the risk of reproductive harm.”

Everything Easy Has Been Done

Cities in California continue to rank at the top of the American Lung Association’s annual ranking of places with the worst air, though the list also includes cities such as Cincinnati and Phoenix. “If Southern California is ever to have consistently clean air, we need to take dramatic new steps,” says Bonnie Holmes-Gen, the Lung Association’s senior policy director in California. “At this point, anything that’s easy has already been done. We need to transition away from petroleum fuel to plug-in electric vehicles and to redesign cities around public transit, biking and walking.”

The EPA has been working for years to help improve air quality, and research on the health impacts of poor air quality has led to higher emissions standards as well as cleaner fuel. Lawmakers in California began passing stricter regulations in the 1960s to reduce what was then and still is some of the worst air quality in the nation and in the world — regulations that had the effect of spurring auto industry innovations in emissions-control technology.

In a compelling op-ed in a Riverside County newspaper this year, three doctors sum up health professionals’ concerns about our dependence on the automobile. Riverside County is part of an area of Southern California known as the “Inland Empire,” which has consistently ranked among the top three regions with the worst air quality in the U.S.

“If doctors were in charge of planning our cities,” write Cameron Kaiser, Richard Rajartnamand and T. Allen Merrit in The Riverside Press- Enterprise, “our cities would look very different. Why? The answer is simple: The epidemic of air pollution and chronic disease in the Inland Empire is fundamentally linked to our built environment and dependence on vehicles.

“As doctors in Riverside County, we spend most of our time treating illnesses such as asthma, obesity, diabetes, heart disease and stroke. These are illnesses that are caused in part by the double whammy of air pollution and a lack of physical activity. We see too many children struggling to breathe from asthma and too many patients die prematurely from these chronic illnesses. Changing the way we plan our cities can help reduce this burden of disease.”

Diesel Death Zone

The corridor stretching from Long Beach north to East Los Angeles is called the “diesel death zone” because of the trucks that rumble up the 710 freeway from the ports of Los Angeles and Long Beach, the two largest ports in the U.S. Scientists have been studying residents of the low-income ethnic communities along the 710, and their conclusion, in the words of Linda Birnbaum, director of the National Institute of Environmental Health Sciences, is that “Living near major roads is hazardous to your health. Period.”

Birnbaum funds many of these researchers, many of whom were quoted in a 2011 Scientific American story about the health threats from traffic pollution. Half the residents of L.A. County — about 10 million people — live within a mile of a freeway, Cone notes, a distance that Dr. Ed Avol, a professor of preventive medicine at USC, describes as “dramatically close.” Dr. Frank Gilliland, director of the Southern California Environmental Health Sciences Center, says the lung function of children who grow up near freeways is about 10 percent lower due to the high levels of ultra-fine particles in the air. USC professor Heather Volk adds that children born to mothers living within 350 yards of a freeway appear to be twice as likely to have autism.

L.A. County environmental health director Angelo Bellamo told Cone that there are at least 90 schools in the Los Angeles Unified School District close enough to freeways that children are highly exposed to traffic fumes. The school district has adopted a policy that prohibits the siting of schools within 500 feet of a freeway unless the district determines there are no other possible sites. But Bellamo is concerned about the 90 schools that are already too close. And he notes that freeways and other heavily traveled roadways are moving closer to existing schools. “There’s a growing body of knowledge [about these health effects],” he says, “and the craziness is that we are still doing it.

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