The fall out from Japan's nuclear crisis is getting into our food chain. The radioactive material leaking from the Fukushima nuclear power plant, are scattered by the sea and wind. It has been detected in the nearby farms. Radioactive material fell onto the surface of vegetables such as spinach and the pastures where dairy cows graze. Japanese government inspectors detected high levels of radioactive iodine and cesium exceeding legal limits in spinach, milk and other produce from Tohoku and Kanto. The prefectures of Fukushima, Ibaraki, Tochigi and Gunma had halted shipments of spinach, kakina greens and milk. Some countries, including Australia, Canada, Hong Kong, United States and Singapore have restricted the import of Japanese food products.
So what exactly is the risk from radiation contaminated food?
Ingesting radioactive material will leads to internal radiation exposure. For dairy products such as milk, the Nuclear Safety Commission has determined that 300 becquerel of radioactive iodine per kilogram and 200 becquerel of radioactive cesium per kilogram are safe for consumption. For vegetables, acceptable levels is 2,000 becquerel and 500 becquerel, respectively. These numerical standards for food and water are determined based on the premise of the radioactive material being ingested for a year. Based on this, the level of the radioactive substance absorbed by the body and the extent of health risk are calculated. The safety limits are then set at a level to avoid the health risks.
Low doses of radiation may not cause cancer. It is no worse than taking an X-ray or flying long distance. Past cases of radiation leaks have shown that nearly half of the people exposed to 3,000 millisieverts would die 60 days if they do not receive medical treatment.
At the levels that have been detected in food, people can still safely consume the food until safer alternatives are secured without facing health risks, according to the Japanese authority.So what exactly is the risk from radiation contaminated food?
Ingesting radioactive material will leads to internal radiation exposure. For dairy products such as milk, the Nuclear Safety Commission has determined that 300 becquerel of radioactive iodine per kilogram and 200 becquerel of radioactive cesium per kilogram are safe for consumption. For vegetables, acceptable levels is 2,000 becquerel and 500 becquerel, respectively. These numerical standards for food and water are determined based on the premise of the radioactive material being ingested for a year. Based on this, the level of the radioactive substance absorbed by the body and the extent of health risk are calculated. The safety limits are then set at a level to avoid the health risks.
Low doses of radiation may not cause cancer. It is no worse than taking an X-ray or flying long distance. Past cases of radiation leaks have shown that nearly half of the people exposed to 3,000 millisieverts would die 60 days if they do not receive medical treatment.
However, this is only based on studies on A-bomb survivors from Hiroshima and Nagasaki. About 28,000 people who were exposed to levels of up to 100 millisieverts were monitored over a 40-year period. About 4,400 of them developed cancer. This figure, however, is less than 2 percent--81 people--higher than the average for people who have not been exposed. Even nuclear experts are divided over the correlation between exposure to less than 100 millisieverts of radiation and higher risks of cancer. Hence, the risk line is set at 100 millisieverts.
In day-to-day life, people are exposed to about 2.4 millisieverts of naturally occurring radiation every year. No upper limits are set on exposure to radiation for medical treatments, such as CT scans, because benefits outweigh the risks. However, as long as there is uncertainty about the effects, people should avoid unnecessary exposure to radiation.
