Answer to Question #10907 Submitted to "Ask the Experts"

Category: Nuclear Power, Devices, and Accidents — Nuclear Accidents

The following question was answered by an expert in the appropriate field:


Before the nuclear accident in Fukushima, I regularly ordered green tea online directly from a Japanese grower in Kyoto. I also bought special brewing vessels made of clay from the Aichi region that help bring out the full taste of the tea. After the accident, I felt I could not obtain enough information to help me assess the risk of radioactive contamination of the tea or of the brewing vessels.

My question has three parts:

  1. How likely is it at this time that tea from the Kyoto region, or clay pots from the Aichi region, have radioactive levels that would pose a health risk? Would teas from the most southern areas (farthest away from Fukushima) be at a lower risk? Although it has now been almost three years, radioactive material is still leaking from the nuclear plant.
  2. How reliable is the testing done by the U.S. government on products from Japan entering the United States in 2013 and 2014? Certainly, they can't test every individual shipment.
  3. Could you recommend labs that would be able to perform radioactive tests on samples submitted by individuals? I am not a scientist myself and would need help to make sure tests are designed such that they would accurately and reliably detect radioactivity.

Thank you for your question to the Health Physics Society regarding possible radioactive contamination in Japanese tea and Japanese clay tea-brewing pots following the Fukushima accident. During the accident, contamination was spread by the winds and through water leaking from the reactor complex itself. Winds during the actual event blew from west to east, meaning the majority of the air releases went out toward the Pacific Ocean and away from Japan. The current releases from the damaged nuclear facilities are mostly water leaking from the complex. That material is migrating toward the Pacific Ocean and has not impacted any tea-growing regions in Japan.

The major tea-growing regions of Japan are mainly east or north of Kyoto. In fact, Kyoto produces only about 5 percent of Japanese teas as compared to the major tea-growing areas. The tea-growing region closest to Fukushima, the Saitama Prefecture, has not had any shipping restrictions due to radioactive contamination of its teas since 2012, as reported by the Japanese Citizens' Nuclear Information Center.

With respect to teas from the Kyoto region, the Kyoto region of Japan is about 560 km southwest of Fukushima. The Kyoto region was not greatly impacted by the atmospheric releases, so teas from Kyoto would not contain any accident-related materials that would be a public health concern. Early into the accident, the U.S. Food and Drug Administration (FDA), which has regulatory oversight of most food products sold in the United States, detected elevated levels of radioactive cesium in one sample of green tea and one sample of ginger powder. It is not clear where these samples were collected and although radioactive cesium was detected in them, the very low concentrations found were within the allowable levels for cesium in foods. Since September 2013, the FDA has not found any Fukushima-related contaminants in the U.S. food supply, as reported on its website. The FDA continues to monitor the import of specific foods from Japan which includes teas from specific areas, but not those from the Kyoto region.

Your question regarding the use of clay pots from the Aichi region is important because clays can bind radioactive materials such as cesium. The Aichi region is about 440 km southwest of Fukushima and about 120 km from the Kyoto area. As in Kyoto, the Aichi area was not adversely impacted by the releases from Fukushima. Clay pots produced there would not contain any accident-related materials that would be a public health concern.

As a professional organization, the Health Physics Society's policy is that we cannot recommend any labs that would test materials for you. We do, however, recommend that you contact your state, county, or provincial health department or radiation protection division for assistance.

Paul Charp, PhD

Answer posted on 3 March 2014. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.