is directing the county health department to review potential health hazards from coal trains that may run through the county en route to

s.

Cogen's request, to be formally announced today, focuses on diesel emissions from locomotives and coal dust from uncovered coal cars. He also wants the emergency management office to study potential delays in emergency response from mile–plus trains.

Activists have asked federal regulators for an independent health review and Gov. John Kitzhaber for a state health department review, to no avail thus far.

"There's been a lot of talk about this on regional, state and national level, but I think it's time for the local level to step up so we can understand how concerned we should be," said Cogen, also chair of the county's board of health.

Three of the five coal export terminals proposed in Oregon and Washington are likely to route coal trains through Multnomah County, as many as 32 a day -- half of them full, half empty. Those three terminals, one in Coos Bay and two along the Columbia River, would ship coal from Montana and Wyoming's Powder River Basin to Asia for electricity generation.

Coal clash

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Railroads and terminal developers say health impacts would be minimal. If they're all fully built out -- highly uncertain -- they'd add nearly 900 permanent jobs, plus construction work, developers say.

Trains account for less than 10 percent of total diesel particulate pollution in the Portland area, according to state estimates, and trains are far less polluting per ton of cargo than trucks. Federal limits will deeply cut emissions from

as fleets turn over.

is a problem near mines, the railroads acknowledge, but diminishes with distance. Coal dust from trains doesn't generate the fine particulates that do the most lung damage, coal terminal supporters say, and exposure near the tracks won't come close to the exposure shown to cause problems for miners.

Washington union leaders, whose members handle coal trains headed to British Columbia ports and the Centralia coal-fired power plant, say their members have reported no health issues related to coal dust. And both BNSF Railway and Union Pacific, the major lines in the West, are requiring mines to spray open-top coal loads with sticky

that the coal industry says cut dust emissions by 80 percent or more.

"Any kind of export business, any kind of transportation, is going to have impacts," said Lauri Hennessey, of the

, a trade group backed by mining companies, terminal developers, railroads and unions. Regulators will explore health issues during permitting, she said, and developers would mitigate problems that come up.

Opponents say older trains spew high amounts of carcinogenic diesel particulates, and there's no guarantee newer trains would be used in the Northwest.

That could harm people living or working close to the tracks, which tend to run through poorer neighborhoods.

On dust, opponents note that some coal-burning utilities are challenging the requirements to use surfactants. And railroad testing found an average of 225 pounds of coal lost from per car during a 567-mile trip. For a 135-car train, that's about 15 tons.

Cogen said he doesn't want to rely on permit reviews, which will lean heavily on data from terminal developers and their consultants.

"We don't have the ability to stop trains and we don't the ability to force (railroads) to cover the trains," he said. "We do have the ability to direct light at the problem and demand protective measures."

Cogen wants a report by year's end.

and a preventive medicine doctor, said staff will review the science to date, but can't take air samples near tracks or do other field work by then.

It's clear coal dust can harm miners, Oxman says -- think black lung disease. But the potential harm from "community exposures" will be much trickier to pin down.

The department will also assess diesel pollution risks from added trains. That will be complicated, too.

The railroads won't specify which routes they'll take. existing traffic varies by line, ranging from 85 a day over the Columbia River rail bridge to about 30 a day on southeast Portland's Brooklyn line to just a handful through the Linnton neighborhood in Northwest Portland.

Cogen is among critics who raise broader concerns about coal export, including global warming impacts. But the health department doesn't feel political pressure for a negative review, Oxman said: "We're here to speak from an objective perspective."