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Wednesday, 16 August 1972
Page: 209

Mr HOWSON - The report of the National Radiation Advisory Committee on the Biological Aspects of the Fallout in Australia from French Nuclear Weapons 1971, which was distributed in printed form recently, falls into 2 parts. The main part of the report is the assessment made by the NRAC of the biological significance of fallout from the 1971 nuclear tests in the Pacific. Appended to this assessment is Report AWTSC No. 3 of the Atomic Weapons Tests Safety Committee on the levels of fallout over Australia from nuclear weapons tested by France in Polynesia from June to August 1971. This latter report was tabled by my colleague, the Minister for Supply (Mr Garland), in April 1972.

The Atomic Weapons Tests Safety Committee is responsible to the Minister for Supply for safety aspects of the use of testing of nuclear explosive devices in Australia, for evaluation of proposals by other countries to explode nuclear devices outside Australia which might give rise to increased levels of radioactivity in Australia, and for monitoring of levels of radioactivity in the Australian environment arising from activities with nuclear explosive devices either in this country or elsewhere. Its members are all physicists in the fields of nuclear, radiation and meteorological physics. The Committee has particular operational responsibilities to monitor fallout in Australia and reports the results of its monitoring on a continuing basis to the Minister for Supply. All its measurements are published as soon as possible and are made available to interested parties. In contrast to the operation role of the Atomic Weapons Tests Safety Committee, the National Radiation Advisory Committee has a purely advisory function. The latter Committee was established by the Government in 1957 to provide scientific information in matters associated with the effects of ionising radiation on the Australian community arising from any source. Since its responsibility is to consider the effects of ionising radiation, including those which might arise from fallout from nuclear explosions, the membership of the Committee is biased towards the biological sciences - genetics, public health, experimental pathology, radiobiology - but also includes several physical scientists with particular expertise in the nuclear sciences. The NRAC is, therefore, a body of scientists with wide experience in appropriate scientific disciplines, charged with making its own independent judgment on the effects of the various sources of ionising radiation on the Australian community.

The National Radiation Advisory Committee has reported in the past on the possible biological consequences of a wide range of sources of ionising radiation including the medical use of X-rays, the tuberculosis case-finding programmes and radiation control programmes as well as fallout from each French nuclear test series in the Pacific. In addition the Committee has from time to time reviewed, in language comprehensible to the lay reader, the current status of knowledge with respect to biological effects of ionising radiation. The most recent report of the Committee of this nature is that dated October 1965. I am informed by the Committee that it is now undertaking another such review in the light of additional knowledge acquired since that time. The future role of the Committee will also, I am sure, include assessments of safety factors in the development of a uranium industry in Australia. (Quorum formed) In its present report the National Radiation Advisory Committee has stated that fallout from the 1971 French nuclear weapons tests presents no hazard to the Australian population. In making this assessment the Committee has, in 2 instances, compared the levels of radiation dose due to fallout with the dose received from natural background to which populations have been exposed since the beginning of life on this earth. In the other instance, the Committee has compared the radiation doses with a radiation protection guide it established in 1965 which is consistent with a similar guide established at about the same time and for the same purpose by the British Medical Research Council.

I have been advised that a wide range of biological effects can be produced in experimental animals or in human being by exposure to large doses of ionising radiation delivered in a short period of time - that is, at high dose rates. The effects may include radiation sickness, cancers of various kinds including leukaemia, opacity of the lens of the eye, some shortening of the life span and hereditary effects. There are, I understand, many technical difficulties which prevent direct evaluation of any effects of radiation doses on experimental animals at low levels approaching that of natural background radiation and even more so at the still lower levels resulting from fallout in Australia. The effects, if any, are so small that their recognition would be extremely difficult even in large and strictly controlled experiments, if these could be undertaken. The difficulties are even greater in the case of man.

On the basis of experimental animal data, and the limited human data, obtained at high doses, international and national bodies have recommended standards for protecting persons against the effects which might arise from sources of ionising radiation. They have considered it prudent to make the working assumption that even down to the lowest radiation dose the risk of producing particular biological effects - for example, cancer or hereditary effects - in humans is directly proportional to dose, without a minimum or threshold dose at which no effect occurs. However, the International Commission on Radiological Protection, a non-governmental international body, has referred to such assumptions as being both 'cautious' and conservative' and stated 'that some effects may require a minimum or threshold dose'. In part of its evaluation of the hazards to health of the 1971 French tests the National Radiation Advisory Committee followed a practice adopted by the United Nations Scientific Committee on the Effects of Atomic Radiation, namely, that of comparing the radiation doses from nuclear weapons tests with the doses inevitably received by the community from natural background radiation.

The average natural background radiation dose to a person in the Australian communities is about 100 millirad a year. However the natural background varies from place to place due to such factors as altitude and the amount of naturally occurring radioactive material in the soil. In a given location the annual dose due to natural sources also varies from person to person due to such factors as the materials used in the construction of buildings in which they live and work, and the amount of time they spend indoors and out of doors. Taking all these factors into account, the actual radiation dose due to natural background radiation received by persons would vary, one from the other, from the annual average by up to about 10 millirad a year. Some of the population living at altitude or in areas of high natural radioactivity would receive annual radiation doses greater than the average by SO per cent or more.

The Appendix to the report of the NRAC shows, for example, that the total external radiation dose from fallout deposited on the ground from the 1971 French nuclear tests was, when reduction factors due to shielding are applied, in all cases less than 0.7 millirad. If the conservative assumption of direct proportionality between dose and biological effects, without a minimum or threshold dose, is applied it follows that this dose would have given rise as a total to less than 1 per cent of the same biological effects in each and every year which are due to the average natural background radiation dose. Any biological effects would have been less than those which would result from the variations which occur in natural background radiation from place to place and for individual to individual. I wish to emphasise that I am not in any way supporting the French tests. The Government has made known its opposition to atmospheric nuclear weapons testing by any nation. However, I believe that it is important to reassure the Australian population that, on the basis of the best independent advice available and contrary to some alarmist views, fallout from the French tests to dale does not constitute a hazard to the health of the Australian population.

I present the following paper:

French Nuclear Weapons Explosions m the Pacific - Ministerial Statement, 16th August 1972.

Motion (by Mr Chipp) proposed:

That the House take note of the paper.

Suggest corrections