Evergreen Public Schools found elevated levels of radon in one of six schools tested in its latest round of campus tests, according to the district’s website.
Radon mitigation company Cascade Radon found elevated levels of the radioactive gas at Mill Plain Elementary School between 4.2 and 6.9 picocuries per liter of air. Radon levels about 4 picocuries are considered unsafe for long-term exposure.
Radon is the second leading cause of lung cancer.
A letter from the district to families circulating on social media reports that Cascade Radon adjusted the school’s ventilation system, increasing the amount of outside air circulating in the building. That reduced the amount of radon in the building, but some areas — though the letter does not specify where — remain at elevated levels.
Riverview Elementary, Fisher’s Landing Elementary, Columbia Valley Elementary, HeLa High School and Wy’east Middle School, meanwhile, were not found to have elevated levels of radon.
The district found elevated levels at some of its campuses in the process of testing this spring. Work is still underway at Orchards Elementary School and Marrion Elementary School to reduce elevated radon levels at those campuses.
