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Radioactive iodine detected in air samples in Hong Kong

Activity of Iodine-131 in Air Sample of King's Park
Activity of Iodine-131 in Air Sample of Yuen Ng Fan
Activity of Iodine-131 in Air Sample of Sha Tau Kok

Remarks:

  • Daily air samples are collected at King's Park and Yuen Ng Fan.
  • Weekly air samples are routinely collected at Sha Tau Kok.
  • Half-life of artificial radionuclide Iodine-131 is 8 days. This means that after 8 days, the radioactivity of Iodine-131 drops to half of its original level, and after 16 days to a quarter and so on.
  • The concentration level required for taking protective actions is called "Derived intervention level" (DIL). The DIL for inhalation of Iodine-131 from the air is 661.38 Bq/m3. (Reference: Report No. 1 of the Radiological Protection Advisory Group, HKSARG: Derived Intervention Levels)
  • The amount of radioactive iodine detected in the air sample is very minute and will have no effect on public health.