|[This is a further reply to the comment by Fang, 20 Dec 2004, in response to Luan's original comment 19 Dec 2004].
The incident of the Co-60 contaminated apartments in Taiwan has developed to be an important case for reexamining of the health effects of radiation and their biological impact. A report appearance in the English Taipei Times in Taiwan was brought to you a month ago by Jim Muckerheide in account for the a sad story of this incident. And another report appeared last week again in the Taipei Times to tell a newly discovery of a Co-60 contaminated apartments. Of course there was also a lot commotion in all the Chinese newspapers and TVs about this matter. This is a common topic that could raise the fear, worry and anxiety of the public I would like to make more explanation about this case, for you to keep abreast and deep understand of the possible impact to the present radiation protection theory, practices and system we are dealing (search radiation on http//www. taipeitimes.com /news /local/2004/ 12/02).
From the account of the new discovery of the contaminated building of the English Taipei Times and other Chinese newspaper and TV, I would remind you the following significant facts:
1. Most contaminated apartments were scattered in Taipei City, Keelung City, Taipei county and Taoyuan county, except the new discovered one is located at Ta-Hu village, Hsin-chu City. It is not supposed to have a contaminated building in this district. So that AEC would plan to have further investigation for all the buildings built between 1982 and 1984 in all counties in Taiwan. The total contaminated apartments might not limit to ~1700, but could be as high as up to 3000, which had often been considered possible.
2. Dr. H.L.Yin, the new director of the radiation departments of AEC disclosed to the Taipei Times that, the highest radiation dose rate measured by AEC on Oct. 19/ 2004 in one of the new discovered building was about 10.4 uSv/hr (natural back ground of 11-13 uSv/hr not included), and the annul dose rate would be about 20.000 uSv/y. AEC is going to measure all the apartments in this building. The total contaminated buildings at present might be over 180, and the total irradiated residents lived in the the contaminated apartments might up to 10,000.
3. If those dose rates were measured with the methods developed by the Institute of the Nuclear Energy Research (INER) and traced them back to 1982-1984 ( for about four half-life in 21 years), the hour dose rates would be 166.4 uSv/hr, (0.166 mSv/hr or 16 mrem/hr) the annul dose rate would be 320,000 uSv ( 320 mSv/y.or 32 rem/y ) Both dose rates are in quite high level. A resident in the apartments might receive many Sv (many hundred rem) of doses in 21 years. AEC did not expressed whether they might be harmful based on LNT model, or beneficial to man as observed by a group of scientists from some institutes in Taiwan. AEC is still waiting the medical health authority in Taiwan to tell public how the residents could be affected by radiation.
About the new discovered of Co-60 apartments, Dr. W.P. Chang, the new head of International Division of the Department of the Health (DOH) did not tell anything to the Taipei Times, but told the Union Times, a important newspaper that, 89 cancer incidences totally had been observed in the residents, most of Thyroid, breast, and leukemia cancers, but such data still had not appeared in the national and international conferences and journals, and the number of cancer incidences could not be interpreted exactly to be the cancer mortality. Mr. Y.L. Wang the chairman of the National Association of Radiation Protection ( former RSPAT) and the winner of lawsuit against AEC, told the Union Times reporter that 27 residents totally died in cancers, but this figure were not ever mentioned and used as evidence in the lawsuit, and never cited by scientists in the conference and journals. Even if Wang¡¦s figure is correct, the mortality of the residents was only about 12.8 persons /100,000 person- year (27/10,000x21 = 27/210,000= 12.8/100,000), which is still much smaller than the cancer mortality of the general population in 2003 which was 156.01 /100,000, and the average cancer mortality during 1982-2003 in about 116/100,000 in Taiwan. That means the 90% of cancers of the residents had been prevented.
The incident of the Co-60 contaminated apartments was incidentally occurred in Taiwan, the radiation doses delivered to the residents individually and collectively were higher than the doses that exposed to the atomic survivors in Japan and emergency workers in Russia, yet they serendipitously demonstrated that chronic radiation was greatly beneficial to the residents. And the radiation from peaceful use of nuclear energy and medical application of radiation is also chronic radiation which should be also always beneficial to man. If such beneficial effects of radiation are true to man, they should be further confirmed by all the national and international radiation scientists and communities in the hoping the nuclear energy not only could benefit to man, but have no radiation risk. Even when a nuclear accident occurred, it could only cause a few workers dead, majority of the public will be benefited. The chronic radiation was also discovered might be effective in immune of cancers and hereditary diseases, it might be used as an important vaccine for man.