Berotec

Nuclear power and biologic effects

(fenoterol hydrobromide)

PRESCRIBING INFORMATION INDICATIONS AND CUNICAL USES Berotec is indicated for the symptomatic relief of bronchial asthma and other conditions in which reversible bronchospasm is a complicating factor such as a chronic bronchitis or emphysema. CONTRAINDICATIONS Like other sympathomimetic amines, Berotec should not be used in patients with tachyarrhythmias or in those with known sensitivity to sympathomimetic amines. Beta-blocking agents, e.g., propranolol, effectively antagonize the action of Berotec. Their concomitant use is therefore contraindicated. WARNINGS Special care and supervision is required in patients with thyrotoxicosis, cardiac arrhythmias and idiopathic hypertrophic subvalvular aortic stenosis, when an increase in the pressure gradient between the left ventricle and the aorta may occur causing increased strain on the left ventricle. Use In Pregnancy: The safety of Berotec in pregnancy has not been established. Use In Children: There is insufficient data at this time to establish the safety and efficacy of Berotec in childre.i. PRECAUTIONS Berotec should be used with care in asthmatic or emphysematous patients whO also have systemic hypertension. coronary artery disease, acute and recurring congestive heart failure, diabetes mellitus, glaucoma or hyperthyroidism. Care must also be exercised in the concomitant use of Berotec with other sympathomimetic amines or MAO inhibitors. As with all sympathomimetic aerosol drugs, failure to respond to a previously effective dose usually indicates a significant deterioration in the patient's asthmatic condition. He should be instructed to contact his physician immediately in these circumstances, and on no account should he exceed the recommended dose of aerosol. Occasional patients have been reported to have developed severe paradoxical airway resistance with repeated use of sympathomimetic inhalant preparations. Fatalities have been reported following excessive use of aerosol preparations containing sympathomimetic amines, the exact cause of which is unknown. ADVERSE REACTIONS The following adverse reactions have been reported at therapeutic dosage levels (1-2 whiffs): tremor, restlessness, palpitations, dizziness, headache, nausea, lightheadedness and weakness. Other occasional reactions include vomiting, heartburn, sweating, nervousness, bad taste, fatigue, prickling and tingling sensations over the body, and agitation. SYMPTOMS AND TREATMENT OF OVERDOSAGE The symptoms of overdosage are those of excess beta stimulation listed under ADVERSE REACTIONS. The use of a beta-blocker should be considered in cases of severe overdosage. DOSAGE AND ADMINISTRATION

Berotec Inhaler:

A single dose of one or two inhalations (0.2-0.4 mg) to control bronchospasm. If required, this dose of 1 or 2 inhalations may be repeated up to 4 times daily. With repeated dosing, drug should not be given more often than every 4 hours. Patients should not exceed a total of 8 inhalations per day (See PRECAUTIONS). AVAILABILITY Berotec Inhaler: Each valve depression delivers 0.2 mg of Berotec as a micronized powder. Each Inhaler Unit contains 200 doses of 0.2 mg Berotec. REFERENCES 1. Leifer, K., and Wittig, H.: /12 sympathomimetic aerosols in the treatment of asthma. Ann. Allergy 35(2):69-80, 1g75. 2. Benjamin, C.: A comparative study of the broncho-dilator effects of five /3-adrenoceptor stimulant drugs in patients with reversible broncho-obetruction. Medical Proceedings 18:1, 35-40, July 1972.

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With major nuclear power stations operating at Pickering and Bruce in Ontario, and after more than 30 years of research and development, Canada has achieved a position of leadership in nuclear technology. Concerns have been expressed about the implications of this technology for the health of the community, and the question is one that has been considered with care. No industrial activity is absolutely safe. Any undertaking entails a biologic cost that must be measured and eventually met by the community, and to this rule the generation of electricity, by whatever means, is no exception. It is not for the scientist, the technologist, or indeed the physician to tell the community what risks should or should not be accepted, but an analysis of operating experience with Canadian nuclear reactors and of the associated hazards is timely. The hazards of concern in exposure to ionizing radiation are carcinogenesis, mutagenesis and shortening of life span. In human populations exposed to ionizing radiation there is an association between the level of exposure and the frequency of cancer. Equally it is clear that radiation is but one of the environmental factors to which Higginson1 has attributed about 80% of all human cancer. The genetic effects of radiation have been demonstrated experimentally, but there is at present no evidence of such effects in the children of heavily irradiated humans. The situation has been summarized in a recently published report,2 the first recommendation of which reads: "At the levels of radiation likely to be permitted in relation to possible somatic effects, the genetic effects should be of little concern." A shortening of life span in human populations exposed to radiation has been suggested by studies on American radiologists who, during the course of their work in the first half of this century, were quite heavily exposed to radiation. However, it is probable that the effect was confined to this particular cohort, which has now moved through the population. Eleven years ago the International Commission on Radiological Protection commented: "The possibility that small doses of radiation have a nonspecific and deleterious effect on life expectancy is not excluded, but the weight of evidence in favour of such an effect is not sufficient to justify any quantitative estimate of risk."3 Therefore of the three possible radiation effects - carcinogenesis,

mutagenesis and shortening of life span - carcinogenesis warrants the most careful consideration in relation to the exposure, of populations to radiation as a result of the development of nuclear power programs in Canada and elsewhere. There is general acceptance of the cautious assumption that a linear relation between radiation dose and carcinogenic effect represents an upper limit of risk. The corollary of this hypothesis is that there is no level of exposure to radiation below which there is no risk of a deleterious effect, although at very low doses this risk may be so small as to be, for practical purposes, negligible. The hypothetical exclusion of a threshold for radiation effect is conservative, but there is as yet no convincing evidence that such a threshold exists. The information on radiation carcinogenesis in man has been examined in two major reports4'5 that consider in detail the effects of ionizing radiation on exposed human populations. From this information it has been concluded that if each member of a population of 1 million people is exposed to 1 rem (a unit of radiation) approximately 150 will die from carcinoma.4 This concept has been questioned, as it involves the extrapolation of data derived from heavily exposed populations to those exposed at much lower levels. While this conservative approach may lead to an overestimate of cancer risk at low levels of exposure, it is properly the present basis for risk calculations. Such a figure must be put into perspective if it is to be used to assess the biologic effects of a nuclear power program. The nuclear power station at Pickering, near Toronto, is one of the largest in the world. The effluents from this station are monitored and surveillance is undertaken of the surrounding environment. From the information obtained it can be calculated that an individual who in 1975 spent the entire year at the plant boundary would have been exposed to less than 5 mrem (5/1000th rem). For the population living in the surrounding area the average exposure would have been probably less than 1 mrem. These figures should be compared with natural background radiation, which amounts to 100 to 150 mrem/yr in most parts of North America. From the risk estimate figure it can be calculated that of the approximately 1500 cancer deaths that will occur annually in any group of 1 million Canadians7 less than one case in such a group living in the

Pickering area may be attributable to radiation from the reactor. This effect cannot be detected by epidemiologic techniques. While it may be reasonable to suggest that no member of the general public should be disturbed by the health risks of a normally operating nuclear reactor, it would be unwise to ignore the fact that people are more disturbed by the possible consequences of an accident in such a reactor. During the 20 years that have elapsed since the first nuclear power reactor in the world became operational in the United Kingdom, there has been no accident in a power reactor that has resulted in the loss of appreciable quantities of radioactivity to the environment. In Canada, during more than 30 years of nuclear research, development and operations, there has not been one radiation injury that has resulted in the loss of a day's work. This is the experience and it has been quantified by sophisticated mathematical models that suggest serious accidents will happen less than once in 1000 reactor-years. Whether or not one accepts the validity of these models, the experience remains a demonstrable fact indicating that although reactor accidents are possible they are improbable. The risk, by reasonable analysis, is sufficiently small that it should not be considered a contraindication to the development of nuclear power in Canada. The nuclear power plant is but one part of the nuclear fuel cycle. For any estimate of total biologic effect to be derived the whole cycle must be considered, from the mining of uranium, through reactor operations to the handling of wastes generated at different stages of the cycle. This type of exercise is equally necessary for hydroelectric power and for electric power generated from other energy sources, such as coal, oil and natural gas. The chief radiation hazard in uranium mining is the release to the working environment of radon, a radioactive gas that is formed during the decay of radium. This gas, together with its radioactive decay products, can be in-

haled in biologically significant quantities if mine ventilation is inadequate. There is a clear relation between the level of radioactivity in mine air and the frequency of lung cancer in uranium miners. A cohort of miners heavily exposed to radiation during the early years of uranium mining is now moving through the population. In this cohort one may expect to find an incidence of lung cancer accounting for approximately 15 deaths per 10 000 manyears of mining.6 This situation has been discussed at length in the report of the Ontario Royal Commission on the Health and Safety of Workers in Mines7 and a number of recommendations have been made. It is apparent, however, that measures taken prior to the publication of the royal commission report have achieved substantial reductions in the levels of radioactivity in the working areas of uranium mines. While there can be no complacency about this problem, it should be recognized that, in terms of electricity produced, the death rate for persons working in coal mining is estimated to be roughly 18 times greater than that for persons working in uranium mining.8 The milling and processing of uranium ores, together with the fabrication of nuclear fuel, are other areas that must be considered. There is no indication that occupational health costs specific to these activities must be met. From the viewpoint of community health, proper provision for the management of wastes arising from these operations is mandatory. This in turn raises the question of how radioactive wastes should be managed. It is one that has aroused considerable public interest because some of these wastes remain radioactive for many thousands of years. The problem is not technically difficult to solve. The technology is available and it is necessary only to ensure that it is operational by the mid-1980s, when it will be required in Canada. Provided that this is done the dose commitment to the public that results from waste management will be so low as to be unmeasurable.

Consideration of the biologic effects of the increased use of nuclear power cannot be separated from the wider question of the extent to which an increase in electric generating capacity is needed. If the community, in its collective wisdom, decides that such a need exists, then in 1977 the options available are limited. It appears unlikely that wind, solar or biomass energies can contribute any substantial segment of power within the next 25 to 30 years, though research should be done to determine the biologic and fiscal economics of these resources. This leaves coal and uranium as the available energy options, and in all probability the needs of the next 25 years will be met by a combination of these two resources. Of the two options, coal has the familiarity associated with long usage, but a great deal more is known about the potential hazards of nuclear energy, and the evidence does not suggest that these hazards are any greater than those that are an accepted part of everyday life. It remains to ensure that the standards of safety already achieved are maintained into the distant future. J.L. WEEKS, MD, IMH Director Health and safety division Atomic Energy of Canada Limited Pinawa, Man.

References 1. HiGoiNsoN J: Present Trends in Cancer Epidemiology, Oxford, Pergamon, 1968, pp 40-75 2. Royal Commission on Environmental Pollution: Sixth Report - Nuclear Power and the Environment, Cmd 6618, London, HMSO, 1976 3. International Commission on Radiological Protection: The Evaluation of Risks from Radiation, pubi no 8, Oxford, Pergamon, 1966, p 15 4. Biological Effects of Ionizing Radiation Report: The Effects on Populations of Exposure to Low Levels of Ionizing Radiation, Washington, National Academy of SciencesNational Research Council, division of medical sciences, 1972 5. United Nations Scientific Committee on the Effects of Atomic Radiation Report: Ionizing Radiation: Levels and Effects, New York, United Nations, 1972 6. PocHIN EE: Estimated Population Exposure from Nuclear Power Production and Other Radiation Sources, Paris, OECD, 1976, p 24 7. Report of the Royal Commission on the Health and Safety of Workers in Mines, Toronto, Ministry of the Attorney General, Province of Ontario, 1976, recommendations 31-53 8. LAva LB, Fasasuso LC: Health effects of electricity generation from coal, oil and nu-

clear fuel. Nucl Saf 14: 409, 1973

The mentally retarded and sexuality The National Institute on Mental Retardation, York University, Toronto, has stated that 3% of Canadians are mentally retarded. Recently there has been an increased effort to assimilate mentally retarded persons into society - to keep them at

home, in school and in jobs - so that they can live to their fullest individual potential. Therefore, personal and social factors that until recently were thought to be beyond the comprehension of mentally retarded people must now be considered. Among these fac-

tors are sexuality and sex education. Daily those who work closely with retarded people seek help, information and material on human sexuality. Physicians, parents and volunteers who work with and teach the mentally retarded have identified and articulated

CMA JOURNAL/SEPTEMBER 17, 1977/VOL. 117 567

Nuclear power and biologic effects.

Berotec Nuclear power and biologic effects (fenoterol hydrobromide) PRESCRIBING INFORMATION INDICATIONS AND CUNICAL USES Berotec is indicated for t...
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