RADIATION MATTERS

As already foreshadowed, concern about health and safety associated with uranium mining and milling overwhelmingly focussed on the hazards posed by ionising radiation. An indication of the range of concern may be discerned from the variety of submissions in which these matters were raised. Apart from submissions from government agencies and mining companies, see, for example, Peter Milton (S 9, 4); Gavin Mudd (S 34); Frank Miller (S 35, 5); Michael Moore (S 36); Friends of the Earth Sydney (S 40, Part 2, 71-82); Social Action Office, Conference of Leaders of Religious Institutes, Queensland (S 55, 6); Peter Jones (S 66); Australian Nuclear Association (S 71, Part 4); Greenpeace (S 73, Part B); Roger Alsop (S 75, 2); Women Opposed to Uranium Mining (S 76, 3-4); Women's International League for Peace and Freedom (S 77, 6); Medical Association for Prevention of War (Australia) (S 79, 9-10); Uniting Church Social Responsibility and Justice Committee (S 83, 15-8); Movement Against Uranium Mining (ACT) (S 89, 5); and Conservation Council of South Australia/Friends of the Earth Nouveau (S 92, 22-8).

Much analysis of radiation matters pivots on a proposition attributed to the National Health and Medical Research Council that "[t]here is no safe level of exposure to ionising radiation" (Australian Conservation Foundation, S 81, 13). (Subsequently, the ACF informed the Committee that attribution of this statement to an NH&RMC publication was a "mistake" and that the NH&RMC had in fact said that "there is a small risk even at very low doses".)

Dr Keith Lokan, Director, Australian Radiation Laboratory, explained the proposition thus:

We would share the opinion of ICRP and the international agencies that that [proposition] is correct. It is an assumption, supported by the theories of radiation biologists, that one would not expect there to be a threshold, and that the consequences of exposure will increase with increasing exposure. It probably is not linear - that is, if you decrease a given dose to half that dose, it is likely at low doses that the future negative impacts would decrease by more than a factor of two. But, yes, it is true that conceptually there is no "safe dose." (11 February 1997, 1073)

In its submission the South Australian Government put the view that such an interpretation of "safe" was not consistent with usual community standards in assessing the risks of everyday activities:

It is frequently stated that "there is no safe level of radiation exposure". This is only true if "safe" is defined as "absolutely no risk at all". Such a statement is analogous to the statement "there is no safe speed in a motor car". If "safe" is taken to have its normal meaning that the level of risk is so low that it is acceptable in the particular circumstances, then "safe" levels of radiation exposure can be defined and an appropriate dose limitation system can be applied. (S 109, 4.2.1, 16)

As has been reported earlier, the occupational dose limit has been reduced to 20 milliSieverts (mSv) per year averaged over a period of five consecutive years with a maximum of 50 mSv in any one year. Both Australian mines, Ranger and the Olympic Dam Operation, are already within the new limit. As the Australian Radiation Laboratory informed the Committee:

For both mines, the annual radiation doses to workers are well below the recommended 50mSv of the Nuclear Codes Mining Code and about one third of the 20 mSv limit recommended by the NHMRC and the NOHSC in 1995. (S 80, 2)

A major reservation about the latest limits is that the trend has been consistently downwards. As described by the Australian Conservation Foundation, "[i]n 1950 the dose limit was reduced from 300 to 150 milliSv per annum. It was reduced again, in 1956, to 50 milliSv. In 1977 the ICRP reaffirmed the 50 milliSv limit. In 1985 the recommended public dose-limit was reduced from five to one milliSv per annum" (S 81, 13, citing Les Dalton, Radiation Exposures, 1991, 205).

A similar observation is made by the Conservation Council of South Australia/Friends of the Earth Nouveau:

The recommended allowable exposure to ionising radiation has been steadily decreasing from the earliest days of radiological protection. There has not been a single case where the allowable dose has been increased. As our knowledge of the effects of ionising radiation increases so the risks associated with it have been found to be higher and higher. There is an irrefutable trend in the assessed risk yet the NH & MRC and other groups whose brief it is to protect people from ionising radiation have not taken this into account. (S 92, 23)

The NH & MRC explain the most recent approach thus:

Risks arising from exposure to radiation should be kept in perspective with other risks, so that society's resources are not inappropriately expended in attempting to contain one particular form of risk while providing too little protection from others. The Recommendations incorporate a system of radiation protection which, if implemented properly, should ensure that risks arising from exposure to radiation remain a minor component of the spectrum of risks to which all people are exposed. (NHMRC, Recommendations for limiting exposure to ionizing radiation (1995) (Guidance note [NOHSC: 3022 (1955)], Radiation Health Series No 39, r-1)

The matter of how conclusive the most recent limits will prove to be was covered during the Committee's public hearings.

Dr Lokan, Director of the Australian Radiation Laboratory, explained that:

. . . a careful and thorough re-evaluation of the radiation exposures indicated that they [the former limits] had been overestimated by about a factor of two. In addition, with the addition of further years of medical data as the exposed population aged, the emerging number of cancers exceeded earlier projections by about 50 per cent. (11 February 1997, 1071)

As a consequence, Dr Lokan concluded:

My opinion would be that they [the dose limits] will not drop further. (11 February 1997, 1073)

Officials from the South Australian Health Commission laid emphasis on the advance in knowledge upon which the 1991 values are based:

While our knowledge will obviously increase in the future, we already have a reasonably good knowledge of radiation effects. A lot of our knowledge depends on the study of the atomic bomb survivors in Japan. Until those who were exposed in that population have all died, we will not have the final information from that population. However, I believe we are now getting close to a very good estimate from that population, so I do not anticipate that there will be such very large changes in the future.

(Mrs J Fitch, Director, Radiation Protection Branch, South Australian Health Commission, 3 March 1997, 1726)

Mrs Fitch's observation was amplified by Dr Crouch, Senior Scientist, Radiation Protection Branch, South Australian Health Commission:

. . . the thing that is driving this discussion is the 50-millisievert limit which was set back in the 1950s or 1960s . . . [T]hat was not much more than an inspired guess because, at that stage, there was very little data from the Hiroshima and Nagasaki victims. So it is not at all surprising that now, when people have had an opportunity to follow them for 30 or 40 years after their exposure, the results are different. (3 March 1997, 1727)

Several submissions were very critical of the time which elapsed between the promulgation of the ICRP value in 1991 and eventual adoption in Australia nearly half a decade later. According to Greenpeace, ". . . Australian regulators have not responded in a timely or proper fashion" (S 73, Part B, 2). The Medical Association for Prevention of War (Australia) told the Committee that "[i]t is appalling to see radiation authorities drag their feet on these regulations" (S 79, 10). For the Conservation Council of South Australia/Friends of the Earth Nouveau the delinquency was even greater:

The recommendations in the document were based on 1991 International Committee on Radiological Protection (ICRP) recommendations, which followed the 1989 US recommendations (BEIR V report), which followed the 1987 UK (NRPB) guidelines, which followed general acceptance of the assessment of data from Hiroshima survivors which was known in 1981. It took the expert NH&MRC Committee 14 years to get to the stage of making recommendations.

This time lag is unacceptable and the delay can be attributed at least partly to the nuclear industry who challenged the analysis of the Hiroshima data and who have a large influence on committees such as ICRP. (S 92, 22-3)

Mr Tim Ferrari, National Industrial Coordinator, Australian Liquor, Hospitality and Miscellaneous Workers Union, was among those concerned by the delay:

I for the life of me cannot work out why there is such a problem with ICRP 60 and why there has been since 1990. Those who say that people have dragged their heels on ICRP 60 are correct. I am one person who can say from my experience that people have wanted to drag their heels on ICRP 60 and I cannot for the life of me think of any other reason than Jabiluka. I think it can be worked out but it is going to cost some money. If that is the problem, let people say so. (11 February 1997, 1404)

Dr Keith Lokan, Director, Australian Radiation Laboratory, explained the process of adopting the ICRP values thus:

You need to understand that in our federation processes like this, the development of new standards, can only proceed at a pace in which they can be developed in a consensual way by all the players. In this case, we produced a first draft document after the publication by ICRP of its recommendations. We circulated that draft amongst all of the afficionados. We went through seven drafts at various times exposing it to interested parties and, ultimately, issuing it for public comment in year four.

By the time we received the public comment, absorbed the public comment, changed it accordingly and took it back to the Radiation Health Committee, we had covered 4 1/2 years. Then it took another half a year for it to go through the formal processes of adoption by the Occupational Health and Safety Commission and the National Health and Medical Research Council.

If not the first, we are among the first countries in the world to have adopted the new recommendations. (11 February 1997, 1074)

Dr Lokan added that "[m]ost countries now are contemplating the adoption of new standards, and more than likely many will take advantage of the basic safety standards produced jointly by the International Atomic Energy Agency, International Labor Organisation, World Health Organisation and Food and Agriculture Organisation because they are tailor-made for adoption as regulatory instruments." (11 February 1997, 1074)

The Committee does not regard delays of several years as acceptable. The relevant authorities need to ensure that the processes are streamlined and operate much more promptly in future. This may be achieved by provisional promulgation of new standards in advance of confirmation following consultation.

Mr Ferrari was also critical of the variations proposed to ICRP which effectively use a 10-year rather than a 5-year averaging period (11 February 1997, 1404).

Dr Lokan explained these changes:

The points of difference between our recommendations and ICRP are: firstly, a more realistic recommendation regarding exposure of the foetus, once a woman employee notifies her employer that she is pregnant. Rather than a limit of two millisievert at the surface of the abdomen, which ICRP proposed, we have used more general words saying that the foetus should be afforded the same protection as members of the public. This allows the regulator to assess the importance of internal exposures from radioactive materials rather than only external exposure.

Secondly, Australian state and territory radiation protection regulators wish to retain an element of flexibility whereby they could consider exceptional circumstances and authorise temporary dose limits different from and greater than a time averaged 20 millisievert per year in order to correct the circumstance. Such circumstances - and none are visualised at this time - would have to be approved for good reason by the regulatory authority on a case by case basis. In all other respects - including the longstanding justification, optimisation, dose limitation philosophy and a commitment to ALARA - we have followed ICRP closely and are in close accord also with the basic safety standards. (11 February 1997, 1072)

Parenthetically it should be noted that not all informed observers endorse the 20 mSv per year value averaged over five years without qualification. Mr R M Fry (then the Supervising Scientist) and Mr M W Carter stated in a paper delivered at an international conference in 1992 that:

The new occupational effective dose limit recommended in ICRP Publication 60 (ICRP 1991) is 20 mSv per year averaged over defined periods of 5 years, with the further provision that the effective dose should not exceed 50 mSv in any single year. Some underground uranium mines may find difficulty in complying with this limit. No country is likely to forego underground uranium mining because of an inability to strictly comply with the new limit if it is considered essential in the national interest. For any departure from strict compliance to be acceptable it must not lead to increased risks to miners. This paper argues that the new ICRP limit, as formulated, is more prescriptive than it need be on strict radiobiological risk grounds. Provided the rate of radiation exposure is limited to avoid deterministic effects, the lifetime risk is largely determined by the accumulated dose, not the rate of dose accumulation. Whilst limiting average yearly exposure to 20 mSv has regulatory convenience, it is arbitrary and there may be industries in which occupational risk can be equally well controlled through a lifetime or career dose limit. It is suggested here that underground uranium mining may be regulated by setting an occupational lifetime effective dose limit, which may be accumulated at rates faster than 20 mSv per year. A career limit for underground uranium mining, which could, using a dose constraint, be set somewhat below the 940 mSv implied by the ICRP recommendations, and a continuing strong emphasis on ALARA, would ensure that miners are at least as well protected as they would be by strict compliance with ICRP 60. Indeed, if the effect of a career dose limit were to shorten the number of years uranium miners spend underground, this would have the benefit of reducing their exposure to the generally much higher conventional risks associated with underground mining. (Abstract. Text attached to S 82)

The Select Committee is not a scientific body and it is not equipped to enter a view on the scientific matters raised by the radiation question. On this basis it has reached the following conclusions.

First, the scientific question is not yet settled. As one witness remarked, "[t]he field is by no means mature" (Dr Philip Jennings, 20 January 1997, 949). The Committee believes that Australian health authorities should continue to assemble and test data to ensure that any stipulated dose level meets the claims made for it. This accords with a theme which has occurred earlier in this report, namely the continuing importance of research.

Secondly, it is also a field where ultimately individuals must make decisions for themselves and their families. The Committee recommends that responsible government health authorities together with mining companies and unions with coverage should ensure that employees are fully briefed on radiation and related hazards, personally, in some plain English documentation and perhaps also by video.

The cost of such briefing should be met by the respective mining companies.

This proposal is not advanced as a criticism of past or present performance. All the evidence available indicates that these have been satisfactory. But it is not sufficient in a field which remains so open and where individuals themselves are entitled to provision of full information as a basis for arriving at a personal decision.

The Committee, however, considers that the present range of practices, especially as currently demonstrated at Ranger, should be regarded as minimum standards. Annual medical checks of employees exposed to radiation should continue. Individuals should receive a post-examination report in plain English.

Any new mines which open should adopt these practices as a matter of routine.

Thirdly, in investigations about the various levels of radiation, the Committee has often been told that the working rule, whatever may be legally a maximum permissible limit, is ALARA - as low as reasonably achievable.

Both mining companies and regulatory authorities should actively continue their pursuit of the ALARA principle and report on the extent to which they succeed in operating well below prescribed levels.

There is also the matter of a national register of people occupationally exposed to ionising radiation in employment. Called the National Radiation Dose Register (NRDR), it is now being established by the Australian Radiation Laboratory following a forum organised in 1990 by the National Occupational Health and Safety Commission. The NRDR is a national database of the personal radiation dose records of all Australians who have been occupationally exposed to ionising radiation.

The NRDR is described by ARL:

The P[ersonal] R[adiation] M[onitoring] S[ervice] at ARL can provide to the NRDR records detailing the external radiation exposure to all workers in Australian uranium mines. Records of internal radiation dose, from the inhalation and ingestion of radioactivity, are held by State health authorities and the employers. Information and advice on the available internal dose records for uranium miners is now being collected by ARL and the NRDR has also approached the uranium mining companies directly for information on worker exposure. With the establishment of the NRDR it will be possible for a worker to obtain from a single source a complete history of radiation exposure throughout the worker's lifetime. It will also have benefits to regulators and users of radiation in the assessment of the effects of changes in practice on occupational exposure and will provide a useful set of data for any epidemiological studies of the effects of radiation exposure. It is expected that the database, including the external radiation dose records for the uranium mining workers, should be in place by late 1996. (S 80, 5)

Notwithstanding action to establish the Register several organisations advocated such a move in submissions to the Committee.

The Australian Conservation Foundation recommended that a national register of all uranium mine and mill workers be established (S 81, 13). Women Opposed to Uranium Mining recommended that "a national register for all radiation workers, not only those employed in mining and milling, should be established and all efforts should be made to track past radiation workers so that epidemiological studies can be undertaken" (S 76, 4). The Medical Association for Prevention of War (Australia) expressed its concern "about the fact that so far Australia has no national system to record the exposure of uranium miners to radioactivity" (S 79, 9).

The Australian Liquor, Hospitality and Miscellaneous Workers Union submitted that:

. . . the uranium industry in Australia has not adequately or responsibly participated in bringing forward comprehensive epidemiological data for each exposed worker in current mining operations to assist the world wide need for such information. Recording exposure levels is important but unless all lifetime factors are also recorded as possible confounding factors then there can never be conclusive results confirming either high or low responsibility levels relating to fatality levels.

Similarly the industry has not given support to maintaining a proper register of uranium workers both present and past, with regular contact maintained with workers who have left the industry or who are now working in other radiation exposed industries, eg mineral sands extraction and processing.

Fry and Carter also state:

"an adequate system of cumulative dose accounting and its strict surveillance for all workers within the industry, and a national mechanism to ensure transfer of health and dose records between employers would be required . . . " (S 82, 3)

There are, nevertheless, reservations about a national register. Mr Tim Harrington, a member of the Environment Committee, South Australian Chamber of Mines and Energy, considered that a national register could have two uses. The first is simply the matter of keeping records of individuals especially if they move from jurisdiction to jurisdiction. At present, Mr Harrington said, ". . . it is up to the receiving state to obtain the radiation records from the state or territory where the person was before. That mechanism actually does work. It may not be as reliable as a national register; therefore a national register has some merit." (24 January 1997, 1046)

But, he continued, discussions for a national register took place in "the context of a permanent repository of information for epidemiological follow-up."

It is extremely unlikely - and some research was published quite a number of years ago - that any future epidemiological study will find concrete evidence of the results of exposure at the sort of radiation doses that people in the mining industry are commonly exposed to. It is a statistical fact that it is going to be extremely difficult and probably unlikely . . . [T]here are people who think that those records will supply concrete evidence of deleterious effects. I do not think, on a statistical basis, that that body of evidence will show that. (24 January 1997, 1046-7)

Relevant to this question of a national register is a matter Dr Leigh raised. He drew attention to differences in methods used by the two mines, Ranger, an open cut mine, and the Olympic Dam Operation, an underground mine, in measuring radiation exposures. Dr Leigh expressed a view that there should be greater consistency in methods used by Ranger, Olympic Dam Operation and any new mines so that there is "standardised confounder data which is essential to any future epidemiological study, ie data on other exposures (eg smoking, asbestos, chemical) which can cause cancer or lung disease which may distort any epidemiological attempt to relate radiation exposure to future cancers or other disease" (J Leigh, 35-6).

The Committee, whilst having regard to various reservations about the statistical feasibility of epidemiological studies in Australia, agrees that Dr Leigh's recommendation should be seriously considered.

Indeed, the Committee recommends that the ARL ensure that a uniform method of measuring, calculating and recording dose limits is adopted and applied in all mines. Public concern about radiation is such that it is not sufficient for mining companies alone to determine how they record exposure to radiation. The purpose of a national register is to find consistency.

The Committee is not satisfied that the matter of career dosage has been examined sufficiently thoroughly by scientific and medical authorities. It is persuaded that the concern about this longer-term aspect of health in the uranium mining and milling industries needs a more coherent response than, as far as the Committee knows, has been yet given. Among the matters to be addressed are the method of determining the career dose limit, and the industry's own response.

It believes that this is a topic on which the ARL could take the lead in consultation with mining companies and unions.

Health authorities should examine a means of compensation for employees who exceed a career dose limit (when determined) prior to retirement age.

When the Committee was finalising its report its attention was alerted to a paper by Professor Wolfgang Kohnlein of Munster, Germany and Rudi H. Nussbaum of Oregon, United States. They summarise their perspective thus:

. . . for decades radiation researchers have focused their attention somewhat myopically on delayed cancer and genetic effects among A-bomb survivors - a highly selected group of individuals - and on much animal and radio-biological research at very high doses. Specific low-dose or low dose-rate studies of populations or human cells, that suggested that ionizing radiation might actually have an increased rather than a reduced biological effectiveness at low doses, have either been rejected outright, or ignored in reviews of radiation health effects. Only very recently have there been persistent suggestions in the literature that such unexpected effects which clash with firmly held beliefs among a majority of radiation experts, might involve hitherto unknown and rapidly saturating complex radio-biophysical or radiobiochemical mechanisms at very low doses, very different from the well-known mutational effects, proportional to dose, . . . ("Reduced Radio-Biological Effectiveness at Low-Rate, Low-Dose Exposures [DREF] : An Unwarranted Conjecture", n.d., 9-10).

The Committee, in the short time available, received brief comment on the Kohnlein/Nussbaum view from Mr P.A. Burns of the Australian Radiation Laboratory:

In their paper, Dr Kohnlein and Dr Nussbaum claim that the risk of developing a fatal cancer is greater than that predicted in ICRP 60. In ICRP 60 this risk is estimated at 5% per Sievert for the general population whereas in their paper this risk is estimated to be 25% . . . Whilst there is some uncertainty regarding these risks estimates it is considered unlikely that they could be wrong by a factor of five. If the risks were as high as suggested then nearly 30% of all cancers in Australia would be attributable to background radiation and it should be possible to observe variations of cancer rates with background radiation. Such variations cannot be observed even with large variations of background radiation, which can vary by a factor of ten around the world.

Further analytical comment from the Australian Radiation Laboratory is in Appendix 4.1.