By John Stang Herald staff writer Hanford's most analyzed mulberry tree shows barely detectable levels of radioactive strontium 90, according to lab tests ordered by the state Department of Health. A human would have to eat 25 tons of mulberries from the tree within one year to absorb a radiation dose of 100 millirem, which is the annual federal limit for someone who does not routinely work in a radiation zone, a draft report states. The site's most scrutinized mulberries grow on a tree near H Reactor. A second tree near the old Hanford townsite that also was tested showed no detectable strontium. The draft report is on the latest study of mulberry trees monitored to track how strontium-laced ground water seeps toward the Columbia River.
Excessive strontium can cause bone cancer.
The matter became an issue after a maverick scientist released two reports theorizing that strontium is flowing into salmon-spawning areas near H and KE reactors. Norm Buske of Spokane, a scientist working with the watchdog organization Government Accountability Project, has been promoting his theory for four months. He has studied mulberry leaves from the Hanford Reach's shoreline for several years. The trees suck up contaminated ground water and retain its radioactive substances. The state health department routinely collects mulberries and other vegetation from the shoreline and tests them for strontium and radionuclides, and Pacific Northwest National Laboratory conducts extensive samplings and tests of mulberry trees, vegetation and ground water from the 300 Area upstream past the Vernita Bridge.