September 13, 2013

Neighborhoods and UW team up to measure diesel exhaust pollution in South Seattle

Environmental & Occupational Health

To measure exposure to diesel exhaust at homes in Georgetown and South Park neighborhoods, UW researchers put up air sampling monitors.

Sam Keller

To measure exposure to diesel exhaust at homes in Georgetown and South Park neighborhoods, UW researchers put up air sampling monitors.

The residents of the Georgetown and South Park neighborhoods in Seattle’s Duwamish Valley now know how much diesel exhaust they are exposed to. The data were collected by the University of Washington School of Public Health and Puget Sound Sage, a nonprofit coalition in Seattle. A report on findings from the air pollution study are published online Sept. 13.

A large volume of traffic travels through these South Seattle communities due to nearby highways, industry, train routes, and the Port of Seattle. Sixty percent of neighborhood residents surveyed in 2009 by Puget Sound Sage believed pollution from commercial trucks affected the health of their families.  Long-term occupational exposures to high concentrations of diesel exhaust have been linked to respiratory and cardiovascular health problems as well as cancer.

“Residents were most concerned about commercial truck traffic. They see these trucks travel through their neighborhoods every day. They wanted us to monitor pollution levels where people lived,” said Dr. Julie Fox, a senior fellow in environmental and occupational health sciences at the UW School of Public Health.

It was in response to community concerns and support from the Kresge Foundation that the UW School of Public Health partnered with Puget Sound Sage to help residents measure levels of diesel exhaust in the South Park and Georgetown neighborhoods.

“We were able to develop a much more refined understanding of exposure  and the impacts of various sources of exposure  for this particular area of the city. Using the skills and expertise from UW scientists to respond to community concerns, we were able to provide detailed community-level data on pollutants that are markers of diesel exhaust,” said Fox.

Researchers collected data over a two-week period in summer 2012 and winter 2012-2013 on four primary pollutants that serve as markers of traffic-related air pollution. They are 1-nitropyrene, a polycyclic aromatic hydrocarbon that is a by-product of combustion from diesel engines; black carbon, oxides of nitrogen, and particulate matter less than 2.5 μm in diameter.

The researchers also compared these measurements to pollutants measured in residential sites in Queen Anne and Beacon Hill, which are located atop hills and have less commercial truck traffic.

Pollution levels in Seattle fall within Environmental Protection Agency national standards for air pollution., The study, however,  was not designed to determine compliance with standards, and 1-nitropyrene and black carbon are not regulated.

“Choosing diesel-specific markers limits direct comparison to other metropolitan areas, but gives us confidence that among the different sources of air pollution we characterized diesel exhaust,” said Fox.

Results indicate that residents of South Park and Georgetown are likely exposed to higher levels of diesel exhaust than residents of  Beacon Hill and Queen Anne. Also, within the two Duwamish Valley neighborhoods, pollution levels varied, even across small areas. Residents near busy roads and industrial areas faced higher levels of diesel exhaust pollution.

Other UW Environmental and Occupational Health Sciences researchers  who worked on the Diesel Exhaust Exposure in the Duwamish Study, also known as DEEDS,  include Dr. Joel Kaufman, Jill Schulte,  Dr. Sheryl Magzamen, a former postdoctoral research scientist, and Nancy Beaudet, of the UW Occupational and Environmental Medicine Clinic.

The project is funded by The Kresge Foundation’s Healthy Environments Program.

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