The Iron Phospho-Gypsum is 6Bq/g which is a very low non-hazardous product by International Standards. But this is above the Malaysian 1Mu/g regulatory standard.
A post by kryten on Hot Copper:
Yearly dose examples
- Maximum acceptable dose for the public from any man made facility: 1 mSv/year
- Dose from living near a nuclear power station: 0.0001-0.01 mSv/year
- Dose from living near a coal-fired power station: 0.0003 mSv/year
- Dose from sleeping next to a human for 8 hours every night: 0.02 mSv/year
- Dose from cosmic radiation (from sky) at sea level: 0.24 mSv/year
- Dose from terrestrial radiation (from ground): 0.28 mSv/year
- Dose from natural radiation in the human body: 0.40 mSv/year
- Dose from standing in front of the granite of the United States Capitol building: 0.85 mSv/year
- Average individual background radiation dose: 2 mSv/year; 1.5 mSv/year for Australians, 3.0 mSv/year for Americans
- Dose from atmospheric sources (mostly radon): 2 mSv/year
- Total average radiation dose for Americans: 6.2 mSv/year
- New York-Tokyo flights for airline crew: 9 mSv/year
- Current average dose limit for nuclear workers: 20 mSv/year
- Dose from background radiation in parts of Iran, India and Europe: 50 mSv/year
- Dose from smoking 30 cigarettes a day: 60-80 mSv/year
The radiation exposure limit set by AELB for the public is 1 mSv/year. Problem SMSL? Do any of your members smoke?
A post by praseo on Hot Copper:
The IAEA concluded in their Lynas report last June that the concentrate being shipped to Malaysia will have a Th-232 activity of about 6Bq/g. The material will be tested prior to shipping to verify. Even though the material is bagged within sealed containers what if some material escapes?
The IAEA report page 33, "A simple calculation shows that a daily ingestion of 100mg of material with a Th-232 activity concentration of about 6Bq/g would give rise to a worker dose of only 0.2 mSv per year."
Allow me to emphasize DAILY INGESTION and 0.2 mSv PER YEAR and consider 250 working days (5 days x 50 weeks) in a year.
" the NRC (U.S. Nuclear Regulatory Commission) requires that its licensees limit maximum radiation exposure to individual members of the public to 100 mrem (1mSv) per year, and limit occupational radiation exposure to adults working with radioactive material to 5,000mrem (50 mSv) per year."
Let's do the math to establish how much Lynas concentrate a worker in the U.S. could ingest and be under the allowable limit for radiation exposure according to the NRC.
If a worker ingests 100mg daily for 250 days and receives a radiation dose of 0.2 mSv per year as the IAEA states, he will have ingested 25,000 mg (100mg x 250 days = 25,000 mg). To receive 1mSv of radiation dose he needs to ingest 5 times the 0.2 mSv amount or 125,000 mg (25,000mg x 5 = 125,000mg). Per year, in the U.S. a worker is allowed 50 mSv exposure. Therefore 50 x 125,000mg = 6,250,000mg = 6250 grams = 6.25 kilograms.
If a U.S. worker eats less than 6.25 kilograms (13.75 pounds) of Lynas concentrate per year he is within the safety standard of 50 mSv of radiation dose per year.
Doubtless, Malaysian workers will be trained and supervised to achieve ingestion of less than 13 pounds of concentrate per year and will remain well within the established safety standards. However, vigilance must be maintained in recognition that it is safely edible (from a radiological point of view) and if found tasty, may be excessively consumed.