Food not checked for radiation poses risk in Fukushima: study


Staff Writer

Eating unchecked homegrown vegetables and wild game from radiation-tainted areas on a regular basis can lead to high levels of internal radiation exposure, according to the results of a study published Tuesday in the U.S. online science journal PLOS ONE.

However, levels of radioactive cesium detected in the bodies of the study’s participants declined once they stopped eating highly contaminated food, said the researchers, who called for renewed efforts to raise people’s awareness of risky foods at a time when public interest appears to be dwindling.

The study focused on Minamisoma, which stretches about 14 to 38 km north of the Fukushima No. 1 nuclear plant. Researchers followed nine people, who were the only ones out of 30,622 examinees from the city to have internal cesium-137 levels greater than 50 becquerels per kilogram in screenings between March 11, 2012, and March 10, 2013. That’s roughly equal to 0.1 to 0.2 millisieverts per year.

Cesium-137 levels among the nine participants ranged from 3,230 to 15,918 becquerels per body, which corresponds to between 0.07 to 0.53 millisieverts per year, the report said. The International Commission on Radiological Protection set a radiation exposure limit under normal situations of 1 millisievert per year and said cumulative exposure of 100 millisieverts would increase the chance of death by cancer by 0.5 percent.

The study said the participants, aged 60 to 74, consumed “homegrown produce without radiation inspection, and often collected mushrooms in the wild or cultivated them on bed-logs in their homes.”

The person with the highest levels regularly ate wild boar meat and river fish, the report said. Wild game, river fish and wild mushrooms are highly contaminated and banned from being shipped out of Fukushima Prefecture.

A few months after being screened, the participants were advised to consume mainly food from supermarkets and to refrain from eating potentially contaminated foods, such as mushrooms, mountain vegetables and wild game, without having it inspected first. The researchers found that the degree of contamination fell across the board. Most of the cesium-137 levels were halved in about three months and dropped to less than a third in six months.

The study was led by Masaharu Tsubokura, a physician at the University of Tokyo’s Institute of Medical Science. He said even though most of the Minamisoma residents’ internal radiation exposure level are nondetectable, it’s time to think about ways to support those who have little knowledge about, or interest in food contamination, as prolonged internal exposure may increase their risk of developing cancer.

  • rupertmja

    The article states that the man`s exposure waas `roughly equal to 0.1 to 0.2 millisieverts per year.` However, I am aware that in calculating this, they take the amount of exposure and `dilute` the effect by calculating it against the entire body weight when in fact, the exposure in the body by a `hot particle` (conveniently not mentioned) will be far far higher in the immediate vicinity of where the said hot particle is located in the body. Sometimes, the numbers lie. And I am of the opinion that `they` lie on purpose.

  • badforu

    This article is only good in furthering the confusion between radiation and radioactive contamination. And once the Radioactive material is metabolized by the body, and it resides in the body, then its there. There isnt alot of known ways to cleanse the body once this happens. And they are only looking for 1 radio active element? They should look for all the elements that was released by fukushima.

    Here is a question i have been wondering. Once the radioactive material is metabolized into one system, does it maintain the half life it had before, like on the short half life idiones. If a childs thyroid got filled up with idione 131, and its half life is 18 days, after 18 days does the damage stop? I doubt it does, but i was just wondering.

  • badforu

    Mr Gilman, question for you. What is the number one defense against radioactive contamination? espeically young children, and especially around nuclear faclitys? Its iodine pills… of the several accidents that man has had concerning radioactive releases, how many times have they handed out iodine? They rather talk the accident down then hand out the pills and deal with the realitys of it. This is why they should not be allowed to deal with nuclear. They are not trustworthy to the degree necessary to have my life in there hands.

  • Phil Blank

    Cesium-137 and strontium-90 are the most dangerous radioisotopes to the environment in terms of their long-term effects.

    Any exposure to radiation is bad, there is NO safe limit of exposure.
    Cesium is one of only three metals that is a liquid near room temperature (83 °F). Thehalf of cesium-137 is 30 years. It decays by emission of a beta particle …