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    • Highway goods corridor surrounded by residential neighborhood /iStockPhoto

Route of a Problem


Goods movement corridors represent a major health concern for the populations that live along them. An FSPH team is studying the impact of an aggressive statewide effort to address the issue.

THE HEAVY-DUTY TRUCKS, trains, ships and equipment involved in the efficient, safe delivery of goods to and from California’s ports are vital to the state’s economic well-being and quality of life. But the environmental and public health impacts of the goods movement and logistics industry are also a source of considerable concern – particularly in Southern California, where each day approximately 40,000 trucks travel the routes to and from the ports of Long Beach and Los Angeles, transporting more than 40 percent of the imports that enter the U.S. in containers.

The increased levels of air pollution in areas along the transit routes, also known as goods movement corridors, are responsible for thousands of deaths and billions of dollars in health-related costs each year, according to a 2011 report from the South Coast Air Quality Management District, whose executive officer, Fielding School alum Barry Wallerstein (D.Env. ’88), has called goods-movement-related pollutants the largest source of air pollution in Southern California. Dr. Michael Jerrett, professor and chair of the Fielding School’s Department of Environmental Health Sciences, notes that the problem also raises concerns about environmental inequities. “The populations living close to these truck routes tend to be low-income and communities of color,” he says.

Each day in Southern California, approximately 40,000 trucks travel the routes to and from the ports of Long Beach and Los Angeles, transporting more than 40 percent of the imports that enter the U.S. in containers.

Jerrett is part of an FSPH team that has been evaluating the impact of a major statewide effort, begun nearly a decade ago, to address the problem. In 2006, the California Air Resources Board and local air quality management districts implemented a comprehensive emissions reduction program for the international and domestic goods movement industry. The aggressive plan identified approximately 200 actions – including mandating that nearly all trucks install diesel exhaust filters on their rigs by 2014 – to reduce the statewide particulate matter emitted from goods movement by 85 percent.

A team that included Jerrett as well as Drs. Ying-Ying Meng (who led the study) and Beate Ritz from the Fielding School faculty conducted measurements at 71 sites in L.A. County and 49 sites in the San Francisco Bay Area to assess the traffic-related pollution levels in 2012 and 2013, in an effort to determine the impact the goods movement emissions reduction plan has had on air quality. Specifically, they wanted to know whether goods movement corridors (defined as places within 500 meters of truck-permitted freeways or main ports in the state) experienced greater reductions in air pollutants in the post-policy years than non-goods movement corridors (locations within 500 meters of freeways where trucks are prohibited) and residential areas.

The study team found that reductions in traffic-related air pollutants in goods movement corridors were significantly greater than in other areas as a result of the policies. “These findings show what we would hope – that the regulatory policies are working as intended, to the particular benefit of these vulnerable populations within 500 meters of major truck routes,” says Jerrett.

Now, the group is preparing to follow up with a study examining whether the exposure reductions have resulted in improvements in public health. Past studies have shown that people exposed to elevated levels of traffic-related pollutants have higher rates of asthma symptoms and reduced lung function, as well as greater susceptibility to cardiovascular disease and certain cancers. Using a large data set of California Medicaid recipients, the FSPH group will analyze the impact of the reduced exposures on health indicators such as medication use, emergency department visits and hospitalizations among populations with chronic conditions living in goods movement corridors.  •