Starting July 11, a low-flying helicopter will measure background readiation levels around Puget Sound, making daily flights between through July 28.

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. Information about the project is available on the agency Aerial Radiological Survey website (www.doh.wa.gov/ehp/rp/rep/aerial.htm).

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. Helicopter survey maps urban radiation.

For more information, please visit www.doh.wa.gov/ehp/rp/rep/aerial.htm