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G M Kendall

Publications and source records attributed to G M Kendall.

12 recordsLinked to original sources
PubMed1992

Mortality and occupational exposure to radiation: first analysis of the National Registry for Radiation Workers.

OBJECTIVE: To study cause specific mortality of radiation workers with particular reference to associations between fatal neoplasms and level of exposure to radiation. DESIGN: Cohort study. SETTING: United Kingdom. SUBJECTS: 95,217 radiation workers at major sites of the nuclear industry. MAIN OUTCOME MEASURE: Cause of death. RESULTS: Most standardised mortality ratios were below 100: 83 unlagged, 85 with a 10 year lag for all causes; 84 unlagged, 86 lagged for all cancers; and 80 for all known other causes, indicating a "healthy worker effect." The deficit of lung cancer (75 unlagged, 76 lagged) was significant at the 0.1% level. Standardised mortality ratios were significantly raised (214 unlagged, 303 lagged) for thyroid cancer, but there was no evidence for any trend with external recorded radiation dose. Dose of external radiation and mortality from all cancers were weakly correlated (p = 0.10), and multiple myeloma was more strongly correlated (p = 0.06); for leukaemia, excluding chronic lymphatic, the trend was significant (p = 0.03; all tests one tailed). The central estimates of lifetime risk derived from these data were 10.0% per Sv (90% confidence interval less than 0 to 24%) for all cancers and 0.76% per Sv (0.07 to 2.4%) for leukaemia (excluding chronic lymphatic leukaemia). These are, respectively, 2.5 times and 1.9 times the risk estimates recommended by the International Commission on Radiological Protection, but 90% confidence intervals are large and the commission's risk factors fall well within the range. The positive trend with dose for all cancers, from which the risk estimate was derived, was not significant. The positive association between leukaemia (except chronic lymphatic leukaemia) was significant and robust in subsidiary analyses. This study showed no association between radiation exposure and prostatic cancer. CONCLUSION: There is evidence for an association between radiation exposure and mortality from cancer, in particular leukaemia (excluding chronic lymphatic leukaemia) and multiple myeloma, although mortality from these diseases in the study population overall was below that in the general population. The central estimates of risk from this study lie above the most recent estimates of the International Commission on Radiological Protection for leukaemia (excluding chronic lymphatic leukaemia) and for all malignancies. However, the commission's risk estimates are well within the 90% confidence intervals from this study. Analysis of combined cohorts of radiation workers in the United States indicated lower risk estimates than the commission recommends, and when the American data are combined with our analysis the overall risks are close to those estimated by the commission. This first analysis of the National Registry for Radiation Workers does not provide sufficient evidence to justify a revision in risk estimates for radiological protection purposes.

Adult↗
PubMed1991

Completeness of follow up in a cohort study of mortality using the United Kingdom National Health Service Central Registers and records held by the Department of Social Security.

STUDY OBJECTIVE: The aim was to evaluate and improve the completeness of follow up in a cohort study of mortality carried out using the UK National Health Service (NHS) Central Registers. SETTING: This was a follow up study of UK servicemen who served abroad in the 1950s and 1960s, including those who participated in the UK atmospheric nuclear weapon tests and experimental programmes. DESIGN: Details of men for whom follow up achieved using the NHS Central Registers was unsatisfactory were submitted to the Department of Social Security (DSS) for tracing, as were details of men born before 1916 and reported by the NHS Central Registers as currently registered with a general practitioner, and a 1% sample of remaining men born in or after 1916. MEASUREMENTS AND MAIN RESULTS: The additional follow up increased the number of deaths fully identified in the cohort by 6.5%. Mortality among those untraced on the NHS Central Registers was substantially greater than in the cohort as a whole (10.2% v 6.9%). Among those reported by the NHS Central Registers as not currently registered with a general practitioner, 2.7% were found to have died, as were 1.1% of men born before 1916 and currently reported to be registered with a general practitioner. As expected there was clear evidence that information about emigrations supplied by both the NHS Central Registers and DSS is far from complete. CONCLUSION: Standardised mortality ratios based on follow up via the NHS Central Registers alone are likely to be somewhat low, and this should be borne in mind when interpreting the data.

Adult↗
PubMed1990

Mortality among United Kingdom servicemen who served abroad in the 1950s and 1960s.

The Registrar General's decennial supplements on occupational mortality provide only limited information on mortality in the armed forces in the United Kingdom. Mortality has therefore been studied among a group of 30,619 United Kingdom servicemen who served abroad in tropical or desert areas in the 1950s and 1960s, and who remained in the services for a total of at least five years. Mortality from all causes of death, all neoplasms, and all other known non-violent causes was lower than that expected from rates for all men in England and Wales, whereas mortality from accidents and violence was raised. These differences remained after adjustment for social class, affected both officers and other ranks, and had not disappeared even after the men had been followed up for at least 20 years. When mortality from 20 specific cancers and 10 other disease groups was examined there were significant excesses for cancers of the oesophagus (standardised mortality ratio (SMR) = 146; p = 0.03) and prostate (SMR = 156; p = 0.03), and significant deficits for cancers of the lung (SMR = 73; p less than 0.001), stomach (SMR = 66; p = 0.002), bladder (SMR = 53; p = 0.02), other specified neoplasms (SMR = 48; p = 0.001), coronary heart disease (SMR = 76; p less than 0.001), bronchitis, emphysema, and chronic obstructive lung disease (SMR = 42; p less than 0.001), and for five further groups of diseases unrelated to smoking or alcohol. Examination of mortality in each of the three services separately identified two specific hazards in the Royal Navy; seven deaths from mesothelioma occurred compared with less than 2.06 expected (p less than 0.005), and there was also an excess of neoplasms and of other diseases associated with alcohol (SMRs of 181 and 229; p = 0.002 and less than 0.001). Mortality from smoking related diseases other than those associated with alcohol was low in all three services, particularly among officers.

Accidents↗
PubMed1988

A summary of mortality and incidence of cancer in men from the United Kingdom who participated in the United Kingdom's atmospheric nuclear weapon tests and experimental programmes.

Altogether 22,347 men who participated in the United Kingdom's atmospheric nuclear weapon tests and experimental programmes in Australia and the Pacific Ocean between 1952 and 1967 were identified from the archives of the Ministry of Defence and followed up. Their mortality and incidence of cancer were compared with those in 22,326 matched controls selected from the same archives. The risk of mortality in the participants relative to that in the controls was 1.01 for all causes and 0.96 for all neoplasms. Thirty eight causes of death were examined separately. Significant differences in mortality were found for leukaemia, multiple myeloma, and other injury and poisoning, with higher rates in the participants, and for cancers of the prostate and kidney and chronic bronchitis, with higher rates in the controls. The mortality from leukaemia and multiple myeloma in the participants was slightly greater than would have been expected from national values (standardised mortality ratios of 113 and 111, respectively), but in the controls it was substantially lower (standardised mortality ratios of 32 and 0, respectively). Examination of the rates of leukaemia and multiple myeloma in groups of participants showed very little difference between groups characterised by recorded doses of external radiation or type of test participation and failed to indicate any specific hazard. Evidence obtained from participants who reported themselves voluntarily (or were reported by relatives or friends) suggested that 17% of participants may have been omitted from the main study group but that any resulting bias was small. Most of the differences observed between the participants and controls were interpreted as due to chance, but some may be due to differences in smoking habits. Participation in the test programme did not seem, in itself, to have caused any detectable effect on the participants' expectation of life, apart from possibly causing small risks of developing leukaemia and multiple myeloma.

Environmental Exposure↗
PubMed1986

A study of worker dose distributions with respect to ICRP dose limitation recommendations.

This paper describes an investigation into the distribution of radiation doses to workers, undertaken at the request of ICRP Committee 4. Three main questions are considered. Firstly, the distribution of annual doses to workers is described. Doses are generally well below the ICRP dose limits and most are below 15 mSv y-1. However, doses are not distributed randomly from year to year. The second part of the paper examines recording levels in use and the implications of using the recording level recommended by the ICRP. The data presented here show that little dosimetric information would be lost and many fewer doses would need to be stored if the ICRP-recommended recording level were used. The last part of the paper considers the distribution of doses in individual monitoring periods. It is shown that the distribution of doses to all individuals in a particular monitoring period is not necessarily the same as the distribution of doses to a particular individual in all monitoring periods. This places limitations on the extent to which missing doses may be estimated from doses to the workforce as a whole.

Air Pollutants, Occupational↗
PubMed1986

Doses to patients from routine diagnostic X-ray examinations in England.

A collaborative survey between the National Radiological Protection Board and the Hospital Physicists' Association has been conducted to ascertain current levels of exposure for patients undergoing 10 routine types of X-ray examination in England. The main part of this study consisted of measurements on nearly 3200 patients attending 20 randomly selected English hospitals. The energy imparted to each patient was determined from a measurement of the total exposure-area product for the examination. In addition, thermoluminescent dosemeters were attached to the patient's skin to enable the derivation of doses to the major radiosensitive organs, either directly or using appropriate conversion factors calculated for a mathematical phantom by a Monte Carlo technique. Histograms are presented showing the wide distributions often observed in the doses for each type of examination. Mean values of exposure-area product, energy imparted to the patient, entrance skin dose per film and organ dose are reported, together with coefficients of variation. Comparison of the results with those from similar surveys in the UK and abroad is complicated by inconsistencies in the reporting of such data, but substantial differences are sometimes apparent, particularly for the estimates of organ doses. The present measurements will provide a useful baseline for future measurements and will be used to evaluate the collective dose to the population from medical exposures and the radiation risks from the various radiological procedures.

Humans↗
PubMed1985

Nuclear medicine activity in the United Kingdom.

A survey of the extent of diagnostic and therapeutic nuclear medicine procedures in the UK has been conducted, and information collected on the types of imaging equipment employed and the typical activities of radiopharmaceuticals administered to patients. A total of 380,000 administrations took place in 1982, corresponding to approximately 6.8 per thousand head of population. 84% were imaging investigations, 13% were non-imaging diagnostic procedures and about 3% were for therapy. Bone scans accounted for 25% of all procedures and 99Tcm was the radionuclide of choice for 75% of investigations. Gamma cameras are superseding rectilinear scanners and most are being purchased together with dedicated image processing computers. Their average annual workload is 922 patients per year. There was considerable variation between the typical administered activities reported by different hospitals for the same procedure, and in some cases the figures reported exceeded the maximum usual activities recommended by the Administration of Radioactive Substances Advisory Committee.

Humans↗
PubMed1983

Dental X-rays.

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Humans↗
PubMed1983

Collective doses and risks from dental radiology in Great Britain.

The continued expansion of dental radiology in Britain up to the end of 1981 is demonstrated, with a rate of increase much in excess of that seen for general medical radiography. Of the total of 7.8 X 10(6) dental X-ray examinations undertaken in 1981 approximately 6.7 X 10(6) were intra-oral, 1.5 X 10(5) were extra-oral and 9.1 X 10(5) were pantomographic. Weighted dose equivalents for typical examinations in each of these categories were calculated using specific weighting factors for the important "remainder" organs. Values of 20 muSv, 30 muSv and 80 muSv were obtained for intra-oral, extra-oral and pantomographic techniques, respectively, corresponding to risks of fatal malignancy of 0.33, 0.5 and 1.3 per million. The estimated collective weighted dose equivalent of 212 man Sv to the population of Britain from the current level of dental radiology is predicted to result in no more than about three extra cases of fatal cancer when the age- and sex-related opportunity for manifestation of radiation-induced cancers is taken into account.

Age Factors↗
PubMed1981

A reappraisal of the genetic consequences of diagnostic radiology in Great Britain.

The National Radiological Protection Board has recently carried out a reappraisal of the annual genetically significant dose (GSD) to the population of Great Britain arising from the practice of diagnostic radiology. The current value of 120 muGy (12 mrad) is indistinguishable from the value determined 20 years ago despite a 48% increase in the number of X-ray examinations performed per head of the population. This is mostly due to a large decrease in the contribution from obstetric radiology and to a marked reduction in the gonadal doses delivered to children for nearly all types of examination. The GSD and the frequency of X-ray examinations in Great Britain would appear to be considerably lower than those found in other industrialized countries and seem unlikely to result in more than 100 cases of serious hereditary ill-health per year at genetic equilibrium. On the other hand, diagnostic radiology is responsible for 87% of the GSD from all man-made sources of population exposure in Great Britain and there is evidence from the data collected for this reappraisal that radiological protection measures could be improved so as to reduce significantly this large contribution without detriment to patient care.

Adolescent↗