Both the state and federal government say a spike in airborne radiation recorded May 5 in the Tri-City area does not appear to be related to the Hanford nuclear reservation.
The U.S. Environmental Protection Agency and the Washington State Department of Health agree that radiation from naturally occurring radon was measured on an EPA monitor.
That does not mean the public should ignore it, however.
It’s a good reminder that radon is common in the Mid-Columbia and people with basements should have them checked, said Earl Fordham, deputy director of the Office of Radiation Protection at the Department of Health. Residents can buy home-testing canisters at some hardware stores or on the internet for as little as $10.
Part of an EPA graph showing the spike in radiation early May 5 has circulated on some blogs, a Russian news outlet and social media, with posters alleging it was caused by releases from Hanford.
Heart of America Northwest in Seattle sent out a news release linking the radiation to a sudden, uncontrolled emission from one of the Hanford nuclear reservation’s underground tanks holding radioactive waste.
The scientists determined that the cause was a temporary elevation of radon levels from the natural decay of certain types of elements.
The Department of Health said that was not possible because the wind was blowing the wrong direction for the radiation to have come from Hanford at the time the reading was taken. The state adjusted the graph to reflect the Pacific time zone and then matched it with wind data.
Increases in airborne radon levels near the earth’s surface can be detected during temperature inversions with low wind, Fordham said.
Other West Coast air monitoring stations also showed increased levels of radiation May 5, he said.
Scientists at EPA’s National Analytical Radiation Environmental Laboratory were automatically notified of the reading of increased gamma radiation at its Tri-City-area air monitor on May 5.
“The scientists determined that the cause was a temporary elevation of radon levels from the natural decay of certain types of elements found in nearly all rocks and soil,” EPA said in a statement.
EPA’s RadNet program monitors the air for radiation to determine levels and trends of natural background radiation and to detect abnormalities, EPA said. It can assist officials in determining whether the public needs to be protected in the case of a radiological incident.