Government tests that detected levels of radioactive cesium exceeding the legal limit in tea products made with famous "Sayama tea," a high-end brand of green tea leaves produced mainly in the southwestern region of Saitama Prefecture, have left a bitter taste in producers' mouths.
Government tests that detected levels of radioactive cesium exceeding the legal limit in tea products made with famous "Sayama tea," a high-end brand of green tea leaves produced mainly in the southwestern region of Saitama Prefecture, have left a bitter taste in producers' mouths.
The association of green tea producers in the prefecture announced on Sept. 14 that it will voluntarily stop shipments and sales of tea leaves produced this year.
But the news about cesium contamination of Sayama tea is all the more shocking to these producers--not just because it threatens the reputation of one of the most highly prized brands of green tea in Japan--but also because earlier sampling inspections by the prefectural government found no problem with locally produced tea leaves.
The results of the surprise radiation tests on food products that the Ministry of Health, Labor and Welfare started in August stunned the green tea industry in Saitama Prefecture.
On Sept. 2 and 5, the ministry announced the results of such tests on 59 food items, including vegetables and seafood. Among them, five tea products were found to contain levels of cesium above the legal limit of 500 becquerels per kilogram. Four of them were products of Saitama Prefecture, and they contained 800 to 1,530 becquerels.
The prefecture accounts for only about 1 percent of Japan’s overall tea production, but Sayama tea is one of the most famous varieties of tea in Japan.
The tea products that were discovered to contain high levels of cesium by the government’s tests are all high-grade articles priced several thousand yen per 100 grams. They were made with the rarest kind of the first picking of tea leaves--plucked very early as young buds. That’s why their contamination was not detected by the prefecture’s earlier inspections.
In May, immediately after cesium exceeding the maximum limit was detected in tea leaves produced in western parts of Kanagawa Prefecture, the Saitama Prefecture government hastily conducted radiation tests on raw tea leaves produced in the prefecture.
The prefectural government examined samples from one growing place each in the three cities of Iruma, Sayama and Tokorozawa, which combined account for 70-80 percent of the prefecture’s total production, according to the local government’s production promotion section.
In June, the local government carried out inspections of tea products, using samples from the three cities plus the additional three cities of Tsurugashima, Hanno and Hidaka. The six cities produce 90 percent of the prefecture’s overall tea output, according to the prefecture’s agricultural product safety section.
But the samples were chosen from widely available products. The prefectural government bought tea products priced 300 to 1,000 yen ($3.90 to $13) per 100 grams through local tea dealers for the radiation tests.
During the period from May through July, the Saitama prefectural government checked 38 kinds of tea products in total. The results of the inspections prompted Governor Kiyoshi Ueda to declare that tea leaves produced in the prefecture were safe.
But the series of tests didn’t cover tea leaves plucked early as young buds.
In June, however, the National Institute of Vegetable and Tea Science issued a warning about possible contamination of young buds. The institution published an analysis showing that cesium that has fallen onto old tea leaves is likely to transfer to young buds just as nutrients transfer from old leaves to new buds as they come out in spring.
The Tea Industry Research Institute of the Saitama Prefectural Agriculture and Forestry Research Center noticed the warning. “We were aware of the theory about (cesium’s) transfer (from old leaves) to young buds, but we didn't think such high levels (of cesium) would be found in buds,” said an official at the research institute.
The prefectural government defends its decision to sample only tea products that are sold in high volume. “We have to check various farm products with our limited inspection capacity,” says an official in charge of the inspections at the government. “We thought we should choose representative products distributed and produced in large quantities for the sampling tests.”
On Sept. 14, the prefecture and the green tea association jointly announced that all the brands of green tea produced in the prefecture will be tested for cesium.
Some 50 to 100 kinds of tea products made with young buds and all other tea products made in the prefecture, which number about 2,500, will be tested. Those that are found to meet the radiation safety standards will immediately be allowed to be shipped, according to the plan.
“We have decided to subject all tea products to radiation tests in order to restore consumers’ confidence in Sayama tea,” said Akira Kaihoku, chief of the prefectural government’s agriculture and forestry bureau.
There are limitations to sampling tests
When the central government first told prefectures to conduct radiation tests on various farm products, tea was not on the list.
After levels of cesium exceeding the safety limit were found in May in tea leaves produced in western Kanagawa Prefecture, however, the health ministry urged tea production areas to expand radiation tests.
Shizuoka Prefecture, which accounts for 40 percent of the nation's tea production, immediately responded to the move and carried out tests on 140 tea products, nearly four times the number checked in Saitama Prefecture.
In principle, Shizuoka Prefecture's radiation tests involve checking one sample each from the 19 production areas in the prefecture for each of the picking periods through the second tea crops.
Like Saitama Prefecture, however, Kanagawa also selects “the most standard products representing the production areas” for the sampling tests, according to the prefecture's tea and agricultural production section.
The central government makes decisions on a shipment ban only for products that have not been shipped yet.
Since tea products from Saitama Prefecture have already hit the market, they are not subject to a shipment ban.
At the moment, such a ban is imposed only on tea leaves produced in Ibaraki Prefecture and certain parts of Kanagawa, Chiba, Tochigi and Gunma prefectures. These prefectures are conducting tests to lift the ban.
“There are inevitably limitations to sampling tests,” said a senior official at the Ministry of Agriculture, Forestry and Fisheries, which supervises farm production. “We need to expand the scope of tests to reduce the number of contaminated products that go undetected.”