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Commission changes mind on beds that emit radon

May 17,2018
The Nuclear Safety and Security Commission has reversed the conclusion of an initial investigation into excessive amounts of radon, a radioactive chemical element that could cause lung cancer, emitted from seven mattresses by domestic bed producer Daijin.

On May 10, the state-run body said that radon emissions from the mattresses were below a government-designated safety ceiling. But on Tuesday, it said all seven violated safety standards for commercial products set by the Act on Safety Control of Radioactive Rays around Living Environment. The commission ordered the recall of the seven mattresses.

Under the act, a consumer is not supposed to be exposed to 1 millisievert (mSv) of radiation a year, but one of the mattresses emitted radon at a rate of nine times the limit.

The mattresses in question are: Green Health 2, which emitted 9.35 mSv of radiation; Neo Green Health (8.69 mSv); New Sleeper (7.6 mSv); Mosel (4.45 mSv); Bellaluce (1.59 mSv); Western Sleeper (1.94 mSv); and Neo Green Sleeper (2.18 mSv).

The emission levels were measured based on the assumption that users breath for 10 hours a day, 2 centimeters (0.78 inches) above the mattress. The 9.35 mSv is equivalent to the radiation dose from 100 X-ray examinations.

The commission reversed its conclusion because it first measured emission from the upper cover of the mattress. The second time, it measured an additional component: sponge in the inner cover.

“We visited Daijin Bed’s office in the initial investigation but had a hard time securing samples,” said an official from the commission. “Those samples we used for the second research were from those Daijin collected from a voluntary recall.”

The radon-laden mattresses consist of two layers of covers. The inner cover is coated with negative ion powder, which the commission identified as monazite, a type of crystal that contains a high percentage of thorium, a weakly radioactive metallic chemical element. Moissanite was the source of radon, it turned out.

Koreans believe negative ions are good for the health.

The commission advised owners of the mattresses to stop using them.


BY SEO JI-EUN [seo.jieun@joongang.co.kr]


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