Puget Sound area ranks high in cancer risk from toxic air pollution, reports say

The cancer risk from toxic air pollution in the Puget Sound region ranks among the highest in the nation, on a par with other major urban areas, according to new federal and state analyses.

But the reports probably overestimate the danger because the data used are 7 years old and don't take into account recent efforts to reduce pollution, particularly from diesel-powered trucks and ships, experts say.

"We feel we've made a lot of progress since 2002," said Seth Preston, spokesman for the Washington Department of Ecology's air-quality programs.

Still, the new reports provide a sobering view of the potential health threat of living in big cities and along major transportation corridors. In a few neighborhoods in Seattle and Tacoma — all close to freeways, ports or industrial areas — the Puget Sound Clean Air Agency (PSCAA) estimates the risk from breathing air pollutants exceeds 1,000 potential cancer cases per million people. That's more than 27 times higher than the national average cancer risk due to toxic air pollutants, estimated at 36 potential cancer cases per million people.

Most neighborhoods throughout the Puget Sound corridor have risk levels of 200 or more potential cancer cases per million, according to PSCAA's analysis.

The calculations come with caveats, including the assumption that a person spends a lifetime in the same neighborhood.

"When you look at these numbers, we still have a huge challenge ahead of us," said Kathy Himes, of PSCAA. "We would love to see potential cancer risk be down at one to 10 in a million."

PSCAA's report is based on data in the Environmental Protection Agency's (EPA) National Air Toxics Assessment, which was released Wednesday. EPA analyzed 2002 emissions for 80 cancer-causing air pollutants and mapped out the relative U.S. risks.

Cancer risks were highest in parts of Los Angeles and Madison County, Ill. They were lowest in parts of Coconino County, Ariz., and Lyon County, Nev.

The study found that emissions of toxic air pollutants declined 42 percent between 1999 and 2002, said Madonna Narvaez, air-toxics team leader in EPA's Seattle office. A study released in 2006 was based on 1999 emissions data.

But EPA does not factor in the cancer risk posed by diesel fumes, which is a big oversight, says Stu Clark, leader of the state DOE's air-quality programs.

"Diesel is the thing that drives the bulk of this risk," Clark said. More than 70 percent of the health risk from air pollution is due to diesel fumes, he said.

Narvaez said that risk is still "controversial."

State and regional experts say there's ample evidence of diesel's dangers, so they included it in their analysis.

Rather than predicting actual disease rates, these studies are valuable for pointing out pollution hot spots and emissions that need to be reduced, Clark said.

Options may be limited for people who live in areas where air pollution is high.

"If you personally want to reduce your exposure, avoiding diesel would be the most important thing," Clark said. "But if you happen to have a house near the freeway, I'm not sure there's much you can do about it."

But new regulations are slashing diesel emissions. In 2006, low-sulfur diesel fuel was introduced. In 2007, tailpipe standards were tightened for new diesel-powered trucks and buses.

In Washington, 7,000 government vehicles, including school and transit buses and dump trucks, have been retrofitted with better emissions controls. And nearly $2 million of federal stimulus money will help retrofit cargo-handling vehicles at the ports of Seattle, Tacoma and Vancouver, Wash.

Information from

The Associated Press

is included in this report.

Sandi Doughton: 206-464-2491