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Journal of the Royal Society of Medicine Volume 83 February 1990
claimed in vitro effects which might compromise the immune system. However these observations are from a very limited number of laboratories and ,th ei aigrklf ce would be increased if they were independently replicated. A plausible explanation for any harmful effect of such weak electric and magnetic fields as we are considering, would be surprising on two grounds. (1) The sort of currents and fields which would would be induced in the body by exposure to an ambient power frequency EMF would be much less than those which are occurring naturally. For example, the natural currents arising from the muscular activity of the heart or the neurotransmitting activity of the brain are in the region of 10 to 100 milli amps per square metre compared with the whole body induced current of about 3 milli amps per square metre from standing in a field of 10 kV per metre, the highest normally encountered by any member of the public. (2) The total energy imparted to a cell by such weak fields is extremely small. It is for this reason that it is necessary to invoke other explanations such as trigger effects or some sort of resonance to explain how such minute quantities of energy could have such apparently significant effects. A magnetic field may change the direction of motion of a charged particle but it can never change its kinetic energy which is why it would be surprising if an oscillating magnetic field was more effective in producing biological effects than an oscillating electric field. While, therefore, it is conceivable that electrophysiological processes in the organism may be affected by exposure to weak electrical or magnetic fields, it is difficult to envisage a mechanism by which such influences may effect cell transformation. The other factor lacking from all the epidemiology is any exposure measurement. Tomenius7 measured fields at the doors of dwellings and Myers et al.8 calculated fields from knowledge of loads and distances. Savitz3 measured fields in some dwellings but no epidemiological study has been based on measured personal exposure and all attempts to estimate this have been based on surrogate estimations such as the distance from lines or the number and proximity of distribution wires - the sow-alled 'wiring configuration'. Good measurements of actual exposures both of the general public of all ages and occupations and of employees in 'electrical industries' are needed
urgently. From the public health point of view Ahlbom9 has estimated that EMFs might cause 1000 childhood
Planning 'new' genetics services
The science of genetics has developed rapidly during the last few years. It is thought that all inherited disorders will be mapped to their chromosomal location by the year 20001. Research suggests that many ofthe major killer diseases have a genetic basis and that it will be possible to screen people for their propensity for serious disorders and ensure that
cancers annually in the USA if the estimated risk ratios from the Wertheimer and Leeperl and Savitz3 studies are confirmed. In the UK the equivalent number might be 150 to 200 cases. If EMFs are shown to have health effects in adults and at the levels postulated by Savitz of about 2 milligauss, then there could be a significant public health problem because of the ubiquity of fields of this magnitude. I think it is clear that the evidence at present is not sufficient to say that there is a problem and far less to quantify it. On the other hand it is not possible to say that there is no problem. Most independent researchers are doubtful that any problem concerning ill health in humans exists or will be found. On current evidence it is my opinion that electric and magnetic fields may have real effects on a broad spectrum of biological systems but that the fields from power frequency systems do not have any significant health effects for the general public. R A F Cox Chief Medical Officer CEGB References 1 Wertheimer N, Leeper E. Electrical wiring configurations and childhood cancer. Am JEpidemiol 1979;109:273-84 2 Repacholi MH. Non-ionising radiations: physical characteristics, biological effects and health hazard assessment. International Radiation Protection Association, 1988 3 Savitz D. Case-control study of childhood cancer and exposure to 60 Hz magnetic fields. Am J Epidemiol 1988;14:337-43 4 Ahlbom A. A review of the epidemiological literature on magnetic fields and cancer. Scand J Work Environ Health 1988;14:337-43 5 Lin R. Mortality patterns among employees of electric power company in Taiwan. Abstract presented to Contractors' Review Meeting, November, Kansas City, Kansas, USA 1987. 6 Milham S Jr. Mortality in workers exposed to electro
magnetic fields. Environ Health Perspect 1985;62:297-300 7 Tomenius L. 50-Hz electromagnetic environment and the incidence of childhood tumours in Stockholm county. Bioelectro-magnetics 1986;7:191-207 8 Myers A, Cartwright RA, Bonnell JA, Male JC, Cartwright SC. Overhead power lines and childhood cancer. In: Proceedings of the International Conference on Electric and Magnetic Fields in Medicine and Biology. London, 1985 9 Ahlbom A, Albert EN, Fraser-Smith A, et al. Biological effects of Power Line Fields. New York Power Lines Project Scientific Advisory Panel Final Report, 1 July 1987
they are aware of, and can avoid, environmental and dietary factors which may precipitate the disease. DNA probes which can read the human genome have provided the major advance in genetics. Much of the work on DNA has been pure research, but there comes a time when research has to be converted into service, with subsequent problems of planning and organization. There needs to be public debate about service development because there are difficult ethical issues to be faced. To achieve this, education of both public and professionals in genetics is essential to clarify the implications for current and future generations.
0141-0768/90/ 020064-02/S02.00/0 © 1990 The Royal Society of Medicine
Journal of the Royal Society of Medicine Volume 83 February 1990
Genetics services in Britain will be developed as regional specialties2. All parts of genetic services need to be developed evenly in conjunction with associated services so that demand for one service (such as DNA analysis) does not put a demand that cannot be met on another (such as the obstetric facilities for obtaining specimens from fetuses). Genetics services plans should start with a list of diseases to be covered. Rare disorders, including most of the single gene and chromosomal defects, are irrelevant to the majority ofthe population but needs and demands for services for these can be predicted accurately and met within available resources. However, concentrating on only the rare disorders would rule out carrier testing for whole populations. Most regions will opt to cover only rare diseases initially, but common polygenic disorders, such as diabetes, need to be brought into a genetics programme when the DNA probes needed to investigate such disorders become available. The cost of services will depend on the type of tests done to diagnose a disorder. Biochemical tests to detect an abnormal chemical or protein produced as a result of inheriting a faulty gene (for example, in phenylketonuria or sickle cell anaemia) are relatively cheap, but in many diseases, the abnormal gene product is not known and testing will have to depend on detection of the gene itself with DNA probes, a process which is more complex and expensive than biochemical tests. However, DNA laboratories are not expensive when compared to the facilities needed for other regional specialties such as heart transplant programmes. Antenatal diagnosis and termination of affected pregnancies is cost effective when compared with the cost of looking after handicapped individuals for the whole of their lives. A study in North West and South East Thames RHAs3 showed that the economics of DNA services is such that detection and termination of only 19 affected pregnancies each year in a Region of 3.5 million residents would result in savings of about £7000 a year in hospital costs alone. The range of detectable disorders expands with each new DNA probe, but laboratory costs are relatively static, so DNA technology becomes more cost effective as the range of diseases detectable expands. The real difficulties in genetic services will be supplying the human side of this new technology. People are needed to diagnose disorders, offer services, obtain informed consent, counsel families on tests available and their results, keep confidential records, arrange storage of DNA for future testing, conduct research, and educate medical students, doctors, other NHS staff, the public and, above all, the media. There have been cogent arguments that only medically qualified staff can absorb and impart all this information and expertise to the public, but the reality is that there will not be enough clinical geneticists in the future to take on the work load. There are currently less than 30 consultants and 10 senior registrars in post in the whole of the United Kingdom4. Work is needed to increase recruitment into the specialty and to train other appropriate health professionals to take on some of these tasks, perhaps using the model of the non-medical genetic counsellors working in the USA.
Thought will have to be given to what role genetic services play at different times in an individual's life. The polymerase chain reaction (PCR) tests means that DNA testing can be done on minute tissue samples and that Guthrie spots (already taken in the neonatal period to detect babies with phenylketonuria and hypothyroidism) could be used to detect babies who are carriers or suffer from other inherited disorders. Some couples will opt to have a carrier profile done when they plan a family. One can only guess how many people want to know their own genetic status, but experience from the United States, where private biotechnology companies already offer services to families willing to pay for it, suggests that there will be a demand for testing in this country. Whether this will be available free under the health service or will become a source of income generation for Regions or the private sector remains to be seen. Facilities will also be needed to store tissue samples taken during an individual's lifetime for reference when other family members want to trace their own inheritance after grandparents or other relatives have died5. Regions also need to make decisions about siting genetic services. Existing laboratories and clinical services have usually developed on sites where interested doctors and scientists work rather than where there is a population needing a service. Laboratories will be sited in hospitals, but some regions may opt to send their specimens to laboratories in other Regions or the private sector. Much of the counselling and educational work can, and should, be done in GP surgeries and people's homes. The use of specialist genetic health visitors to take family histories at home, track down relatives, take blood samples and encourage clinic attendance can greatly enhance the effectiveness and efficiency of peripheral clinics held outside the major service sites by clinical geneticists. They can also ensure that families receive help and counselling after difficult decisions about terminating a pregnancy. The 'New Genetics' offers an exciting challenge for the health professionals of the next century, creating demand for services which did not previously exist and needing a large input into health education and service planning and organization. It remains to be seen whether the health service can rise to the challenge. Jean Chapple Consultant in Obstetric and Perinatal Epidemiology North West Thames Regional Health Authority References 1 Cooper DN, Schimidtke J. Human gene cloning and diseases analysis. Lancet 1987;i:273 2 Department of Health Circular 1988 EU88)P/195 Genetics Services 3 Chapple JO, Dale R, Evans BG. The New Genetics: can it pay its way? Lancet 1987;i:1189-92 4 Harris R. Make way for the New Genetics. Br Med J
1987;295:349-50 5 Meredith AL, Upadhyaya M, Harper PS. Molecular genetics in clinical practice: evolution of a DNA diagnostic service. Br Med J 1988;297:843-6
65
Journal of the Royal Society of Medicine Volume 83 February 1990
claimed in vitro effects which might compromise the immune system. However these observations are from a very limited number of laboratories and ,th ei aigrklf ce would be increased if they were independently replicated. A plausible explanation for any harmful effect of such weak electric and magnetic fields as we are considering, would be surprising on two grounds. (1) The sort of currents and fields which would would be induced in the body by exposure to an ambient power frequency EMF would be much less than those which are occurring naturally. For example, the natural currents arising from the muscular activity of the heart or the neurotransmitting activity of the brain are in the region of 10 to 100 milli amps per square metre compared with the whole body induced current of about 3 milli amps per square metre from standing in a field of 10 kV per metre, the highest normally encountered by any member of the public. (2) The total energy imparted to a cell by such weak fields is extremely small. It is for this reason that it is necessary to invoke other explanations such as trigger effects or some sort of resonance to explain how such minute quantities of energy could have such apparently significant effects. A magnetic field may change the direction of motion of a charged particle but it can never change its kinetic energy which is why it would be surprising if an oscillating magnetic field was more effective in producing biological effects than an oscillating electric field. While, therefore, it is conceivable that electrophysiological processes in the organism may be affected by exposure to weak electrical or magnetic fields, it is difficult to envisage a mechanism by which such influences may effect cell transformation. The other factor lacking from all the epidemiology is any exposure measurement. Tomenius7 measured fields at the doors of dwellings and Myers et al.8 calculated fields from knowledge of loads and distances. Savitz3 measured fields in some dwellings but no epidemiological study has been based on measured personal exposure and all attempts to estimate this have been based on surrogate estimations such as the distance from lines or the number and proximity of distribution wires - the sow-alled 'wiring configuration'. Good measurements of actual exposures both of the general public of all ages and occupations and of employees in 'electrical industries' are needed
urgently. From the public health point of view Ahlbom9 has estimated that EMFs might cause 1000 childhood
Planning 'new' genetics services
The science of genetics has developed rapidly during the last few years. It is thought that all inherited disorders will be mapped to their chromosomal location by the year 20001. Research suggests that many ofthe major killer diseases have a genetic basis and that it will be possible to screen people for their propensity for serious disorders and ensure that
cancers annually in the USA if the estimated risk ratios from the Wertheimer and Leeperl and Savitz3 studies are confirmed. In the UK the equivalent number might be 150 to 200 cases. If EMFs are shown to have health effects in adults and at the levels postulated by Savitz of about 2 milligauss, then there could be a significant public health problem because of the ubiquity of fields of this magnitude. I think it is clear that the evidence at present is not sufficient to say that there is a problem and far less to quantify it. On the other hand it is not possible to say that there is no problem. Most independent researchers are doubtful that any problem concerning ill health in humans exists or will be found. On current evidence it is my opinion that electric and magnetic fields may have real effects on a broad spectrum of biological systems but that the fields from power frequency systems do not have any significant health effects for the general public. R A F Cox Chief Medical Officer CEGB References 1 Wertheimer N, Leeper E. Electrical wiring configurations and childhood cancer. Am JEpidemiol 1979;109:273-84 2 Repacholi MH. Non-ionising radiations: physical characteristics, biological effects and health hazard assessment. International Radiation Protection Association, 1988 3 Savitz D. Case-control study of childhood cancer and exposure to 60 Hz magnetic fields. Am J Epidemiol 1988;14:337-43 4 Ahlbom A. A review of the epidemiological literature on magnetic fields and cancer. Scand J Work Environ Health 1988;14:337-43 5 Lin R. Mortality patterns among employees of electric power company in Taiwan. Abstract presented to Contractors' Review Meeting, November, Kansas City, Kansas, USA 1987. 6 Milham S Jr. Mortality in workers exposed to electro
magnetic fields. Environ Health Perspect 1985;62:297-300 7 Tomenius L. 50-Hz electromagnetic environment and the incidence of childhood tumours in Stockholm county. Bioelectro-magnetics 1986;7:191-207 8 Myers A, Cartwright RA, Bonnell JA, Male JC, Cartwright SC. Overhead power lines and childhood cancer. In: Proceedings of the International Conference on Electric and Magnetic Fields in Medicine and Biology. London, 1985 9 Ahlbom A, Albert EN, Fraser-Smith A, et al. Biological effects of Power Line Fields. New York Power Lines Project Scientific Advisory Panel Final Report, 1 July 1987
they are aware of, and can avoid, environmental and dietary factors which may precipitate the disease. DNA probes which can read the human genome have provided the major advance in genetics. Much of the work on DNA has been pure research, but there comes a time when research has to be converted into service, with subsequent problems of planning and organization. There needs to be public debate about service development because there are difficult ethical issues to be faced. To achieve this, education of both public and professionals in genetics is essential to clarify the implications for current and future generations.
0141-0768/90/ 020064-02/S02.00/0 © 1990 The Royal Society of Medicine
Journal of the Royal Society of Medicine Volume 83 February 1990
Genetics services in Britain will be developed as regional specialties2. All parts of genetic services need to be developed evenly in conjunction with associated services so that demand for one service (such as DNA analysis) does not put a demand that cannot be met on another (such as the obstetric facilities for obtaining specimens from fetuses). Genetics services plans should start with a list of diseases to be covered. Rare disorders, including most of the single gene and chromosomal defects, are irrelevant to the majority ofthe population but needs and demands for services for these can be predicted accurately and met within available resources. However, concentrating on only the rare disorders would rule out carrier testing for whole populations. Most regions will opt to cover only rare diseases initially, but common polygenic disorders, such as diabetes, need to be brought into a genetics programme when the DNA probes needed to investigate such disorders become available. The cost of services will depend on the type of tests done to diagnose a disorder. Biochemical tests to detect an abnormal chemical or protein produced as a result of inheriting a faulty gene (for example, in phenylketonuria or sickle cell anaemia) are relatively cheap, but in many diseases, the abnormal gene product is not known and testing will have to depend on detection of the gene itself with DNA probes, a process which is more complex and expensive than biochemical tests. However, DNA laboratories are not expensive when compared to the facilities needed for other regional specialties such as heart transplant programmes. Antenatal diagnosis and termination of affected pregnancies is cost effective when compared with the cost of looking after handicapped individuals for the whole of their lives. A study in North West and South East Thames RHAs3 showed that the economics of DNA services is such that detection and termination of only 19 affected pregnancies each year in a Region of 3.5 million residents would result in savings of about £7000 a year in hospital costs alone. The range of detectable disorders expands with each new DNA probe, but laboratory costs are relatively static, so DNA technology becomes more cost effective as the range of diseases detectable expands. The real difficulties in genetic services will be supplying the human side of this new technology. People are needed to diagnose disorders, offer services, obtain informed consent, counsel families on tests available and their results, keep confidential records, arrange storage of DNA for future testing, conduct research, and educate medical students, doctors, other NHS staff, the public and, above all, the media. There have been cogent arguments that only medically qualified staff can absorb and impart all this information and expertise to the public, but the reality is that there will not be enough clinical geneticists in the future to take on the work load. There are currently less than 30 consultants and 10 senior registrars in post in the whole of the United Kingdom4. Work is needed to increase recruitment into the specialty and to train other appropriate health professionals to take on some of these tasks, perhaps using the model of the non-medical genetic counsellors working in the USA.
Thought will have to be given to what role genetic services play at different times in an individual's life. The polymerase chain reaction (PCR) tests means that DNA testing can be done on minute tissue samples and that Guthrie spots (already taken in the neonatal period to detect babies with phenylketonuria and hypothyroidism) could be used to detect babies who are carriers or suffer from other inherited disorders. Some couples will opt to have a carrier profile done when they plan a family. One can only guess how many people want to know their own genetic status, but experience from the United States, where private biotechnology companies already offer services to families willing to pay for it, suggests that there will be a demand for testing in this country. Whether this will be available free under the health service or will become a source of income generation for Regions or the private sector remains to be seen. Facilities will also be needed to store tissue samples taken during an individual's lifetime for reference when other family members want to trace their own inheritance after grandparents or other relatives have died5. Regions also need to make decisions about siting genetic services. Existing laboratories and clinical services have usually developed on sites where interested doctors and scientists work rather than where there is a population needing a service. Laboratories will be sited in hospitals, but some regions may opt to send their specimens to laboratories in other Regions or the private sector. Much of the counselling and educational work can, and should, be done in GP surgeries and people's homes. The use of specialist genetic health visitors to take family histories at home, track down relatives, take blood samples and encourage clinic attendance can greatly enhance the effectiveness and efficiency of peripheral clinics held outside the major service sites by clinical geneticists. They can also ensure that families receive help and counselling after difficult decisions about terminating a pregnancy. The 'New Genetics' offers an exciting challenge for the health professionals of the next century, creating demand for services which did not previously exist and needing a large input into health education and service planning and organization. It remains to be seen whether the health service can rise to the challenge. Jean Chapple Consultant in Obstetric and Perinatal Epidemiology North West Thames Regional Health Authority References 1 Cooper DN, Schimidtke J. Human gene cloning and diseases analysis. Lancet 1987;i:273 2 Department of Health Circular 1988 EU88)P/195 Genetics Services 3 Chapple JO, Dale R, Evans BG. The New Genetics: can it pay its way? Lancet 1987;i:1189-92 4 Harris R. Make way for the New Genetics. Br Med J
1987;295:349-50 5 Meredith AL, Upadhyaya M, Harper PS. Molecular genetics in clinical practice: evolution of a DNA diagnostic service. Br Med J 1988;297:843-6
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