A University of Utah expert in the measurement of radiation has returned from the Soviet Union where he met with scientists developing techniques for measuring radiation released dur-inr2]ing accidents such as the one at Chernobyl in 1986.
Edwin H. Haskell, research assistant professor in the Division of Radiobiology and director of the U. Thermoluminescence Laboratory, conferred with Galina Hutt, head of the Palaeodosimetry Laboratory, Institution of Geology, Estonian Academy of Sciences.Hutt received a grant from the Soviet government to develop an accident radiation dosimetry laboratory modeled largely after the one at the U. of U.
The U.'s TL Laboratory has pioneered development of sensitive techniques to measure thermoluminescence, the light given out when heat is applied to a substance that has been exposed to radiation.
"We take cores from commonly found building materials such as bricks, tiles and porcelain plumbing fixtures and examine the quartz crystals in them. They don't give out light when heated unless they've been dosed with radiation and then the amount of light is proportional to the radiation," Haskell said.
"The firing of the building brick during manufacture erases any history of radiation in the quartz, so this material is excellent for determining the amount of gamma radiation to which homes and other structures have been exposed after a nuclear accident or testing," he explained.
The U's TL Laboratory has made measurements of the 1950s and '60s fallout radiation from the Nevada Atomic Test Site near Las Vegas and also participated in studies at Hiroshima and Nagasaki where atomic bombs were dropped during World War II.
The Japanese TL study was in conjunction with a larger effort to assess the validity of international radiation exposure limits, Haskell said. These limits are based largely on the health effects of the 100,000 survivors of the atomic blasts.
In 1983-88, the laboratory worked in southern Utah where original estimates of radiation doses were based on theoretical calculations, extrapolations and meter readings made at the time of the atomic testing.
The TL techniques used by the U. laboratory allow for present-day measurements of radiation doses delivered decades earlier. The final report on fallout in Utah, as measured by the TL Laboratory, is expected to be released soon and will be a direct check on the validity of the original estimates, Haskell said.
"We feel confident of our southern Utah measurements. We went to Japan midway in the Utah project," he said. "That study involved blind interlaboratory comparisons and calibrations. In addition, several southern Utah samples were analyzed independently by two British laboratories as well as our own."
Other collaborators in Japan were the Nara University of Education and the National Institute of Radiological Science, both Japanese institutions, and Oxford University and Durham University, both in Great Britain.
Haskell and Hutt of the Soviet Union would like to develop an arrangement similar to that in Japan to assess the effects of the Chernobyl disaster, but international politics, he said, may be the determining factor.