27 Mars 2012
March 28, 2012
As stricter limits on radioactive cesium in food will go into effect Sunday, authorities and institutions affected by the new limits are making final preparations.
The Chiba prefectural government has introduced the new limits ahead of schedule, and makers of instruments for measuring cesium are receiving last-minute inquiries from customers concerned about the new limits, which are stricter than global standards.
Consumers continue to eye food warily after the outbreak of the crisis at the Fukushima No. 1 nuclear power plant that has shaken public trust in food safety. "To restore people'zs trust in food, we must conduct inspections thoroughly," an official in charge of enforcing new limits said.
In the morning of March 21, officials of the Chiba prefectural government and the Asahi municipal government collected cauliflower and cabbage for inspection before shipment from a farm in Asahi, which was hit by the March 11, 2011, tsunami, resulting in the death or disappearance of 15 people. The officials sealed the vegetables carefully in plastic bags to prevent anything from tainting the samples.
The farmer who provided the vegetables looked serious while watching the officials. "I'm confident nothing will be detected on my vegetables. However, I want people to eat my vegetables without worrying," he said.
The samples were sent to an inspection facility in Tokyo the same day.
Based on the Food Sanitation Law, the new limits were mandated by the Health, Labor and Welfare Ministry to minimize people's food radiation exposure.
The limits require that cesium not exceed 100 becquerels per kilogram for regular food items such as meat and vegetables. Considering the effect of radiation on children, the limits on milk and baby food are set at 50 becquerels per kilogram. For drinking water, the limit is set at 10 becquerels per kilogram.
With some exceptions food shipped after Sunday must meet the new criteria. The Chiba prefectural government calculated that it would take about 10 days for newly harvested vegetables to be put on sale to apply the new limits. Municipalities in the prefecture were instructed to apply the new limits from inspections conducted on March 21.
Chiba is one of the nation's largest agricultural producers, shipping a variety of vegetables to Tokyo and surrounding prefectures.
The prefecture was included in areas subject to the stricter inspections under the health ministry's guidelines on inspections, which were made in accordance with the new cesium limits. The prefecture is required to conduct inspections more frequently than prefectures such as neighboring Saitama.
A Chiba prefectural government official in charge of enforcing the new limits said, "I believe none of our food will exceed the limits, but to relieve consumer anxiety, we must conduct strict inspections regularly."
The new cesium limits on drinking water will be 20 times stricter than the current limits. To inspect drinking water accurately, measuring instruments--such as germanium semiconductor detectors--need to accurately measure cesium at the level of about one-tenth the limit for drinking water.
The Kanagawa Water Supply Authority, which provides water to Yokohama, Kawasaki and other cities, received a germanium semiconductor detector on March 19 after ordering it in autumn. "It took about six months to receive the detector due to short supplies, but I'm relieved it arrived just in time," an authority official said.
In some areas, it takes two days to deliver water to households. Observing extra caution, the organization began testing water to an accuracy of 1 becquerel on Monday.
Some inspection instruments owned by local governments will be unable to handle the new cesium limits without updates as the new limits require more accurate instruments. Inspection accuracy can be improved if more time is spent on inspections, but that decreases the amount of food that can be inspected daily.
Hitachi Aloka Medical, Ltd., a measuring instrument maker based in Mitaka, Tokyo, has received about a dozen inquiries every day recently from local governments and companies asking how to comply with the new limits without increasing inspection time.
The company said it had advised callers to update their instruments' software or use more efficient containers for testing.