Food Safety Focus Banner

To the main pageNext Article

Food Safety Focus (205th Issue, August 2023) – Article 1

Food Safety Concern on Radioactive Contamination

Reported by Dr. Tony CHOW, Principal Medical And Health Officer,
Risk Assessment & Communication Division, Centre for Food Safety

Recently, the media has been voicing concerns over the discharge of nuclear-contaminated water from the Fukushima nuclear power station (FNPS) and its possible contamination of the marine environment and seafood. Ensuring food safety is the Hong Kong SAR Government's prime consideration. Following the FNPS incident (Fukushima incident) in 2011, the Administration has imposed import control measures on Japanese food. In light of the latest findings and development, the Administration has been reviewing the import control measures on food products imported from Japan.

Japan's Discharge Plan

The Government of Japan plans to discharge the nuclear-contaminated water generated in the process of cooling the reactors at the FNPS into the ocean in the summer of 2023. The nuclear-contaminated water had direct contact with active raw materials of the nuclear reactor and thus contains a high concentration of radioactive substances. If Japan proceeds with the discharge as planned, it will last for 30 years. During this long period of time, if the purification system fails to operate effectively, it can pose significant risks to food safety and marine ecology. The plan has aroused concern from the international community and the public.

International Atomic Energy Agency's Review

The Task Force set up by the International Atomic Energy Agency (IAEA) has been reviewing Japan's discharge plan. The Task Force conducted visits to Japan and published review reports to make suggestions on some technical and regulatory aspects of the discharge plan to the Japanese authorities. The IAEA published the report in July 2023 on the review before the discharge, and indicated that the review will continue during the discharge.

Enhanced Testing on Imported Japanese Aquatic Products

According to a report issued by Tokyo Electric Power Company Holdings (TEPCO) earlier, a fish sampled from the port area of the FNPS was found to contain 18 times the Codex guideline level of the radioactive substance Caesium. Caesium can be taken into the body by eating food or drinking water. After ingestion, it is absorbed into the bloodstream, distributes throughout the body, and tends to concentrate in muscles. The fish, if consumed, may pose a risk to health and increase the likelihood of inducing cancer.

In view of the report of the fish sampled in Fukushima exceeding the Codex guideline level, the Centre for Food Safety (CFS) has adjusted the corresponding monitoring work and enhanced the testing on imported Japanese aquatic products. The concerned fish was caught in May 2023 and the analytical report was uploaded on TEPCO's website on 5 June 2023. In fact, the CFS has since mid-June expanded the scope of testing to cover all Japanese aquatic products.

Myth 1: Consumption of iodine-rich foods such as iodized salt as a prophylactic measure

In the previous nuclear emergencies where radioactive iodine might have been involved, iodide tablets would be distributed by the health authority as some form of protection against radiation effects by preventing the uptake of radioactive iodine by the thyroid gland.

However, there is no scientific evidence to suggest that iodine-rich foods and iodized salt, would have similar radiation protective effect as iodide tablets. For iodized salt, its iodine content is relatively low. Moreover, one has to take about 2.5 to 5 kg of iodized salt a day in order to absorb the equivalent dose of iodine that is contained in an iodide tablet. Consuming an excessive amount of salt is harmful to health especially for those with high blood pressure, heart disease or kidney disease.

Myth 2: Measurement of radiation with self-purchased portable radiation detectors

Ionising radiation detectors (commonly known as nuclear radiation detectors) for professional uses need to have the required accuracy and sensitivity and to be calibrated regularly by professional bodies to make sure they give accurate and reliable results. On the contrary, self-purchased portable radiation detectors may not have the required measurement capability as well as relevant professional certification and calibration, and cannot replace radiation monitoring and assessment by professional equipment and personnel. Hence, members of the public may not be able to determine radiation levels in food by using self-purchased nuclear radiation detectors.

Advice to the Public

Advice to Trade