PORTLAND, Ore. – Residents in The Dalles finally have the results from an air monitoring study the Oregon Department of Environmental Quality conducted last year, but officials aren’t announcing any immediate changes pertaining to the railroad tie plant at the center of air quality concerns.
The DEQ has fielded hundreds of complaints from The Dalles residents about the century-old plant Amerities, which treats wooden railroad ties for Union Pacific using the coal-tar byproduct creosote. After the ties are dunked in creosote, they’re dried in open air near the small community’s downtown core.
The process releases chemicals including an acrid-smelling polycyclic aromatic hydrocarbon (PAH) called naphthalene. The levels released by Amerities are within the limits of what the DEQ allows, but some residents say the smell is overwhelming and they worry it causes health problems.
According to the DEQ, naphthalene can cause cancer over time. At high levels, it can also cause immediate health problems including headaches, skin lesions and the potentially life-threatening condition of hemolytic anemia.
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The DEQ’s study found levels of naphthalene and other PAHs that were higher than the long-term health benchmark set by the Oregon Health Authority of 0.03 micrograms per cubic meter, which means what OHA says is unhealthy to breathe over 70 years. The levels were all lower than the newly created short-term benchmark of 200 micrograms per cubic meter, which would cause health problems if someone breathed the air for 24 hours. There is no medium-term benchmark set by OHA.
It was the first long-term air quality study to ever take place in The Dalles.
“At times these chemicals were present at levels of concern,” the DEQ assessment said.
The initial study ran from June to August and tested three locations in The Dalles. All of the locations had levels higher than the long-term benchmark but none reached the short-term benchmark.
The highest levels were found at the Wasco County Building, which is located near the Amerities plant in downtown The Dalles. Those levels were up to 190 times higher than the long-term benchmark. High levels of other PAHs were also found at the county building.
The DEQ moved one monitor in August and tested a new location on Old Dufur Road for a month. Levels at that location were as high as 1.95 micrograms per cubic meter, or 60 times the long-term benchmark.
The study also found as the air temperature increased, so did naphthalene levels. On hot days naphthalene levels were particularly bad.
The DEQ said Amerities is a significant contributor to naphthalene in The Dalles but other sources also release naphthalene. Cities often have naphthalene levels of around 1 microgram per cubic meter due to vehicle exhaust and asphalt.
In December, Amerities switched its creosote formula to one that has less naphthalene. Some residents have reported that they continue to smell naphthalene strongly, according to DEQ complaints.
The Oregon Health Authority said they aren’t advising residents to take special precautions based on the data, but anyone with concerns should talk with their doctor.
The federal Agency for Toxic Substances and Disease Registry will analyze the data and determine whether long-term exposure of that level of naphthalene is harmful to the community.
The DEQ said they plan to conduct another air quality assessment in The Dalles this year.
A public meeting to discuss the air quality data is scheduled for March 21 at 6 p.m. at Columbia Gorge Community College.