Lessons from the  nuclear incidents in Fukushima, Japan show the value of a project to measure  background radiation levels in several parts of the state. A low-flying  helicopter will gather radiological readings this summer, starting next week  around Puget Sound.

Radiation detection equipment mounted in a helicopter  will measure “gamma emitters” like cesium and radioactive iodine — materials  that would likely increase in a radiation emergency. This kind of material  releases X-rays, or gamma radiation, a type that can be easily measured from the  helicopter. State radiation experts expect to find natural radioactivity and  material produced by licensed radioactive material users such as hospitals.

The helicopter will fly a grid pattern at an altitude of  about 300 feet to collect data. Mapping the normal amounts and location of  radioactive material will provide a baseline for comparison to assess  contamination if there were a nuclear incident like the events in Fukushima.  Sampling in that area of Japan after the nuclear reactors were damaged produced  radiation readings, but there was no baseline for comparison so it was unclear  how much higher the levels had grown.

The Washington State Department of Health is overseeing the project as the U.S.  Department of Energy’s Remote Sensing Laboratory Aerial Measurement System  conducts the flyover. The project has been in planning since 2009 and is funded  by a grant from the U.S. Department of Homeland Security.

The data collected will be part of a report after quality  assurance review. The report will be available to the public, though some  information may be withheld for national security reasons. If levels of  radioactivity are high enough to pose any health concern, the source will be  investigated.

The flyovers will start in Seattle and Bellevue before  moving to other areas of King and Pierce Counties, including Tacoma. During the  Puget Sound flyovers, the helicopter will be based at Boeing Air Field and will  make daily flights between July 11 and 28.