Wild mushrooms, a seasonal delicacy in many parts of Japan, have lost their magic.

Tourism industry officials and restaurant operators have been aghast to learn that wild mushrooms picked far from the site of the nuclear disaster in Fukushima Prefecture last year are showing high levels of radioactive cesium.

Last year, only wild mushrooms picked in Fukushima Prefecture were found to have cesium levels that exceeded legal standards.

This year, however, wild mushrooms from as far away as Aomori, Nagano and Shizuoka prefectures, all more than 200 kilometers from Fukushima, have been found to be contaminated with cesium....

One reason for the increase in such restrictions this year is a lowering of the legal standard for cesium from 500 becquerels per kilogram to 100 becquerels.

As of Nov. 16, officials said 93 municipalities in 10 prefectures, including Fukushima, had a shipment restriction in place.

For five prefectures--Aomori, Saitama, Yamanashi, Nagano and Shizuoka--wild mushrooms constitute the only produce for which a shipment ban is in effect.

Cesium levels have also risen in various areas compared with last year.

According to tests requested by the central government, the highest levels recorded this year were 120 becquerels in Aomori Prefecture, up from only 60 becquerels last year; 2,100 becquerels in Nagano Prefecture (1,320 becquerels last year); and 3,000 becquerels in Tochigi Prefecture (134 becquerels last year)...