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Biomedical subjects

V Beral

Publications and source records attributed to V Beral.

At least 145 records · Page 8Linked to original sources
PubMed1988

Reproductive factors and risk of ovarian cancer: a prospective study.

Associations between reproductive factors and risk of ovarian cancer were examined in a prospective study of 60,565 women in Norway. A total of 445 women were diagnosed as having ovarian cancer during follow-up, from 1961 through 1980. The highest risk was observed among nulliparous women, and the risk decreased significantly with increasing parity. The estimated odds ratio for women with 5 or more births compared with one birth was 0.46, after adjustment for age, urban/rural place of residence and occupational class. Neither age at first or last birth, nor age at menarche or menopause, nor marital status, showed significant associations with ovarian cancer risk after adjustment for parity. The apparent protective effect of high parity was observed for epithelial as well as non-epithelial cancers, and for the separate histological types of epithelial cancer except mucinous cystadenocarcinomas.

Age Factors↗
PubMed1988

Mortality in women in relation to their childbearing history.

With data from the Office of Population Censuses and Surveys' longitudinal study the mortality of currently married women aged under 60 in 1971 was investigated in relation to the number of liveborn children reported at the 1971 census, adjusting for their husbands' social class. Women who had never had children experienced a higher mortality from many causes of death than the parous women, and this was probably due, at least in part, to selective factors. When the analysis was confined to parous women mortality from diabetes mellitus and cervical cancer increased significantly and oesophageal cancer decreased significantly with increasing number of liveborn children. Mortality from all circulatory diseases and from hypertensive disease, ischaemic heart disease, and subarachnoid haemorrhage tended to rise with parity, though the trends were not statistically significant. Mortality from breast cancer decreased significantly with the number of liveborn children, but only when nullipara were included in the analyses. These data suggest that there may be residual and cumulative effects of childbearing which influence patterns of disease in the long term.

Adolescent↗
PubMed1988

A review of epidemiological studies of the health effects of living near or working with electricity generation and transmission equipment.

In the last ten years there has been increasing concern that the extremely low frequency (ELF), non-ionising electromagnetic fields emitted by electrical installations and equipment using alternating current at 50-60 Hertz might have long-term effects on health. Studies of the association between disease and residence near installations transmitting or generating electricity and studies of the health of workers in the electrical industry are reviewed. Most of the investigations relate to cancer, although other conditions such as outcome of pregnancy have been studied. The most consistent finding is that electrical workers appear to be at increased risk of leukaemia, especially acute myeloid leukaemia. The effect is small. Combining the results of eleven separate investigations suggests an 18% increase in the risk of leukaemia (RR = 1.18, 95% confidence interval (CI) 1.09-1.29) which is partly or wholly due to a 46% increase in the risk of acute myeloid leukaemia (RR = 1.46, 95% CI 1.27-1.65). It is not clear whether this increase is specific to certain types of work within the electrical industry. Nor is it possible to determine from the available data if the increase in leukaemia is due to electromagnetic fields or to other factors to which electrical workers are exposed. There is no clear association between cancer risk and residence near sources transmitting electricity, although some data suggest that there may be small increases in leukaemia in those living very close to the sources. The relationship between adverse outcome of pregnancy and exposure to sources of ELF electromagnetic fields needs further investigation. Studies of the possible effects of ELF electromagnetic fields on health are hampered by problems in measuring exposure and by the ubiquity of exposure in the community.

Adolescent↗
PubMed1988

Adverse reproductive outcomes in women who subsequently develop rheumatoid arthritis.

The rates of adverse reproductive outcomes in 40 women with rheumatoid arthritis (RA) were compared with 67 of their unaffected female relatives. All women were aged between 35 and 65 years at the time of inquiry. Seven of the women with RA reported a perinatal death (six stillbirths, one early neonatal death) compared with one women in the unaffected group: estimated age adjusted relative risk (R) = 12.4, 95% confidence interval (95% CI) 1.6-91.1. The rate of spontaneous abortions was, however, not significantly different between the two groups (R = 1.2, 95% CI 0.5-2.9). All the perinatal deaths occurred before clinical disease onset in the women with RA. It is possible that in these two groups of women with a similar genetic background perinatal loss may be related, at least in part, to disease expression.

Abortion, Spontaneous↗
PubMed1987

Childhood leukaemia in the West Berkshire and Basingstoke and North Hampshire District Health Authorities in relation to nuclear establishments in the vicinity.

During the years 1972-85, 89 children aged 0-14 were registered with leukaemia in the West Berkshire and Basingstoke and North Hampshire District Health Authorities. Two nuclear establishments are located within the health authorities, and a third is situated nearby. Fifty of the 143 electoral wards in the two district health authorities lie wholly within, or have at least half their area lying within, a circle of radius 10 km around the establishments. In those 50 electoral wards 41 children aged 0-14 were registered with leukaemia, 28.6 registrations being expected on the basis of leukaemia registration rates in England and Wales (incidence ratio = 1.4, p less than 0.05). This excess was confined to children aged 0-4, among whom there were 29 registrations of leukaemia, 14.4 being expected (incidence ratio = 2.0, p less than 0.001). In the remaining 93 electoral wards there was a small and non-significant increase in the number of registrations of leukaemia at age 0-14 (48 observed, 40.8 expected; incidence ratio = 1.2). There was no obvious trend in the incidence of childhood leukaemia over the 14 years and the overall occurrence of the malignancy in the 143 electoral wards was consistent with a random distribution. In the surrounding Oxford and Wessex Regional Health Authorities the number of registrations of leukaemia at age 0-14 was virtually identical with that expected on the basis of registration rates in England and Wales (362 observed, 372.5 expected; incidence ratio = 1.0). These data indicate that in the two district health authorities studied there was an excess incidence of childhood leukaemia during 1972-85 in the vicinity of the nuclear establishments. In the West Berkshire and Basingstoke and North Hampshire District Health Authorities an average of 60,000 children aged 0-14 lived within a 10 km radius of a nuclear establishment each year. The normal expectation of leukaemia in these children was two cases a year, whereas the recorded incidence was three cases per year, representing one extra case of leukaemia each year among these 60,000 children.

Adolescent↗
PubMed1987

Further assessment of the effects of occupational radiation exposure in the United Kingdom Atomic Energy Authority mortality study.

The United Kingdom Atomic Energy Authority mortality study was designed to investigate the relation between exposure to ionising radiation and mortality among the authority's employees. The present paper describes some of the problems encountered in assessing occupational exposure to low dose radiation and examines whether the study's conclusions about the relation between exposure and mortality could be affected by the methods used. The study covered the years 1946 to 1979 during which time the frequency with which personal film dosimeters were issued changed from weekly to monthly, and the threshold level below which measurements were not made decreased 20-fold. Exposure from "below threshold" readings made an important contribution to total exposure in the early years. Estimates, based on the remeasurement of a sample of old films, indicated that the average whole body exposure before 1961 may have been about double that which was measured. Furthermore, although records were kept of when dosimeters were lost or damaged, the associated exposures were unknown and could only be estimated. Workers whose dosimeter readings were missing for more than 5% of the time during which they were monitored had higher all cause mortality (p = 0.04) and higher mortality from accidents and violence (p = 0.05) than other radiation workers. The results of analyses of mortality in relation to whole body exposure were compared when the exposures included estimates of the below threshold and missing exposures and when these exposures were assumed to be zero. Some of the findings differed, but none changed sufficiently to alter the general conclusions. Although the trend in mortality from all cancers changed from one in which the increase with exposure was far from statistically significant (p = 0.3) when the below threshold and missing values were assumed to be zero to one that approached significance (p = 0.06) after they were estimated, calculations of the annual excess deaths from cancer per unit dose resulted in broadly similar estimates. Studies of workers exposed to ionising radiation usually focus on mortality in relation to whole body exposure. In the present paper its relation to neutron and surface exposure is also examined. Workers with measured neutron exposures had significantly lower all cause mortality than other workers with a radiation record (p = 0.03). Surface exposure was significantly related to mortality from all cancers (p = 0.02) and prostatic cancer (p less than 0.001). Some data on cancer registration are presented but these cannot be readily interpreted because cancer registration details were available only for ex-employees who may not be typical of the workforce as a whole.

Humans↗
PubMed1985

Collection and validation of data in the United Kingdom Atomic Energy Authority mortality study.

The United Kingdom Atomic Energy Authority mortality study investigated the relation between mortality and recorded exposure to ionising radiation among employees working at the authority's seven establishments between 1946 and 1979. This report examines the design of the study and methods of data collection and validation. The completeness of the study population was deemed to be unsatisfactory at two establishments, where records of employment before 1965 had been destroyed. Assessment of the magnitude of the deficit led to the conclusion that the data from these establishments were too incomplete for inclusion in the mortality analysis. At the other establishments validation showed that the data collected were accurate and unbiased. Certain characteristics of the 39 546 employees included in the mortality analysis were identified which were relevant in interpreting the findings.

Data Collection↗
PubMed1985

Mortality of employees of the United Kingdom Atomic Energy Authority, 1946-1979.

An analysis was conducted of 3373 deaths among 39 546 people employed by the United Kingdom Atomic Energy Authority between 1946 and 1979, the population having been followed up for an average of 16 years. Overall the death rates were below those prevailing in England and Wales but consistent with those expected in a normal workforce. At ages 15-74 years the standardised mortality ratios (SMRs) were 74 for deaths from all causes and 79 for deaths from all cancers. Mortality from only four causes was above the national average--namely, testicular cancer (SMR 153; 10 deaths), leukaemia (SMR 123; 35 deaths), thyroid cancer (SMR 122; three deaths), non-Hodgkin's lymphoma (SMR 107; 20 deaths)--but in none was the increase significant at the 5% level. Half of the authority's employees were recorded as having been monitored for exposure to radiation, their collective recorded exposure being 660 Sv (65 954 rem). Among these prostatic cancer was the only condition with a clearly increased mortality in relation to exposure. Of the 19 men who had a radiation record and died from prostatic cancer at ages 15-74 years, nine had been monitored for several different sources of exposure to radiation. The standardised mortality ratios were 889 (six deaths) in employees monitored for contamination by tritium, 254 (nine deaths) in those monitored for contamination by other radionuclides, and 385 (nine deaths) in those with dosimeter readings totalling more than 50 mSv (5 rem); but the same nine subjects tended to account for each of these significantly raised ratios. Because multiple exposures were common and other relevant information was not available the reason for the increased mortality from prostatic cancer in this population could not be determined and requires further investigation. Excess mortality rates of 2.2 and 12.5 deaths per million person years per 10 mSv (1 rem) were estimated for leukaemia and all cancers, respectively. The confidence limits around these estimates were wide, included zero, and made it unlikely that the International Commission on Radiological Protection's cancer risk coefficients were underestimated by more than 15-fold. Thus despite this being the largest British workforce whose mortality has been reported in relation to low level ionising radiation exposure, even larger populations will need to be followed up over longer periods before narrower ranges of risk estimates can be derived.

Adolescent↗
PubMed1985

Occupational mortality among women in England and Wales.

Occupational mortality in women who died in England and Wales from 1970 to 1972 was analysed. Many of the associations found were consistent with those that have been described for men, with high mortality ratios for cirrhosis in barmaids and publicans, for suicide in the medical and allied professions, and for respiratory disease in textile workers. Parity is a determinant of patterns of disease in working women, and the relative excess of cancer of the breast, ovary, and uterine body in professional and clerical workers probably reflected the high proportion of nulliparous women in these groups. Other associations may have reflected true occupational hazards; one observation requiring further attention was the high proportional mortality ratio for anaemia in textile and clothing workers. The description of the occupational mortality among women in England and Wales is hampered by the incomplete recording of information about women's occupations at registration of death. As women now constitute 40% of the workforce, often have their own specific occupations, and possibly also have their own diseases related to specific occupations it is time for the registrar's guidelines on the recording of women's occupation--last reviewed at the beginning of this century--to be revised.

Adolescent↗
PubMed1985

Long term effects of childbearing on health.

Information on whether a woman had ever had any children was recorded for all deaths registered to ever-married women in England and Wales between 1938 and 1960. Analysis of the relation between parity and cause of death for 1.2 million women aged 45-74 years revealed that parous women had lower mortality from breast, ovarian, and endometrial cancer than did nulliparous women but a higher mortality from diabetes mellitus, gallbladder disease, cancer of the uterine cervix, nephritis and nephrosis, hypertension, ischaemic and degenerative heart disease, cerebrovascular disease, and all causes of death. There is a parallel between the long term effects of pregnancy and of oral contraceptives on health.

England↗
PubMed1984

Home births in England and Wales, 1979: perinatal mortality according to intended place of delivery.

A survey was carried out of all 8856 births occurring at home in England and Wales in 1979. Of these births, 67% had been booked for delivery at home, 21% had been booked for delivery in hospital, 3% had not been booked, and for 9% the intended place of delivery was unknown. The perinatal mortality varied almost 50-fold according to the intended place of delivery, ranging from 4.1/1000 births in those booked for delivery at home to 196.6/1000 unbooked births. Deliveries that occurred at home but had been booked for a hospital consultant unit were associated with a perinatal mortality of 67.5/1000. Births that had been booked for delivery at home included the smallest proportion of babies of low birth weight: 2.5% weighed 2500 g or less compared with 18% of those booked for consultant units and 29% of those not booked. Within these low birthweight groups there were noticeable differences in perinatal mortality; births booked to occur at home had the lowest mortality and unbooked births had the highest. Perinatal mortality among babies who weighed more than 2500 g was generally low irrespective of the intended place of delivery; the only exception was in babies whose delivery had not been booked. In all groups perinatal mortality was considerably higher in nulliparous than parous women. Women booking a delivery at home are clearly a selected group, and some may have been transferred to hospital during labour and were thus not included in the survey. Nevertheless, these data suggest that the perinatal mortality among births booked to occur at home is low, especially for parous women.

Adult↗