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N D McGlashan

Publications and source records attributed to N D McGlashan.

At least 19 recordsLinked to original sources
PubMed2003

Changes in the geographical and temporal patterns of cancer incidence among black gold miners working in South Africa, 1964-1996.

We describe here the results of the final 8 years of geographical and temporal data of a 33-year study of the cancer experience of 12.8 million man-years of black miners working on the gold fields of South Africa over the period 1964-96. These workers were recruited from 15 territories, the major areas during the most recent period being Lesotho (26.8%), Transkei (21.5%) and Mozambique (15%). The earliest analyses, 1964-71 and 1972-79, showed hepatocellular and oesophageal cancers to be the most frequent cancers. The final analysis, for 1989-96, however, shows marked temporal changes in the relative position of four cancers or grouped malignancies: respiratory cancer up by 236%, hepatocellular carcinoma down to 32%, oesophageal holding steady, and lymphatic system cancers up by 420%, almost certainly because of association with HIV/AIDS infection. Significant geographical variations occurring between the home areas of the miners are important, as mining operations have little to do with the cancers that develop. The causes are essentially socio-environmental rather than occupational, and this means that the rates of the major cancers in the miners are surrogate measures of the same cancers in the home areas.

Black People↗
PubMed1998

South African asbestos: production, exports, and destinations, 1959-1993.

Production and export figures of South African asbestos were analyzed over 1959-1993. They show stable sales of chrysotile. Those of crocidolite and amosite reached their peaks in the mid-1970s, after which trade fell drastically, crocidolite to 5% of its earlier peak and amosite to nil. Factors responsible for these virtual collapses were health issues, stricter legislation in First World countries, and litigation. In 1992, 21 countries continued to import crocidolite, although in reduced quantities. In the early 1960s, Europe and North America were the major recipients of South African asbestos. By 1989-91, these regions were surpassed by the Far East, which took over 90% of chrysotile and 70% of amosite. For crocidolite at that time, the Middle East took nearly 40%, Europe 28%, and Africa 21%. This implies that the newly importing countries can confidently expect an increase in asbestos-related disease and death well into the twenty-first century, even if the trade ceased now.

Asbestos↗
PubMed1996

Maternal selenium levels and sudden infant death syndrome (SIDS).

BACKGROUND: The possibility is tested that low anti-oxidant status and/or low levels of selenium (Se) might predispose to Sudden Infant Death Syndrome (SIDS). AIM: This study was undertaken to collect evidence on the Se status of pregnant and non-pregnant women and newborn babies and to establish whether babies who later died of cot death had significantly divergent levels of blood Se at birth. METHODOLOGY: Aliquots of blood were collected from all newly pregnant mothers in Tasmania and from the cords of all newborn babies. These were analysed for Se and glutathione peroxidase (GPx) content and compared by season and with non-pregnant, age standardised blood donors in three areas of Tasmania and three mainland Australian States. RESULTS: Cot death babies' cordbloods were not significantly different in Se or GPx-status, in this small sample, from those of other babies, nor was a seasonal variation in these parameters demonstrated among 390 randomly selected Tasmanian mothers. Mothers-to-be showed a decrease in enzyme levels during pregnancy and Tasmanian blood donors had significantly lower levels than donors from other States. CONCLUSION: While no evidence can safely be drawn about a relationship between Se or GPx-status and SIDS, this study provides base level measures for populations showing that Tasmanian residents have low levels of these anti-oxidants.

Adult↗
PubMed1991

Low selenium status and cot deaths.

Selenium is a naturally occurring trace element essential to the health of many mammal and avian species. Low levels of selenium are evidenced by a variety of symptoms, mainly in the cardiac and musculo-skeletal systems. Tasmania and South Island, New Zealand, both have low soil levels of selenium and high rates of cot death. Evidence is presented to suggest that these may be related via a pathway involving maternal selenium status during gestation or low selenium content in mothers' milk.

Female↗
PubMed1989

Sudden infant deaths in Tasmania, 1980-1986: a seven year prospective study.

This investigation was carried out by questionnaire to parents of SIDS cases and two controls for each case and aimed to follow up the fact that Tasmania has been shown to have an unusually high rate of this cause of death. Both chi 2 and relative risk calculations were employed. The high rate of SIDS of the 1970s has been confirmed in this series in the 1980s. Many of the epidemiological findings are closely in line with those found internationally. Of particular usefulness are new indications which lie within parental choice; cigarette smoking by parents leading to passive smoking by the baby carries a high relative risk (RR = 3.0, P less than 0.001) as does sleeping in the prone position (RR = 1.9, P less than 0.01) as against sleeping in a lateral position. Tenants of Housing Department homes are at raised risk of SIDS (RR = 2.6, P = 0.001). Density of persons within the home also raises the risks to babies (P less than 0.001) and a well ventilated bedroom lowers the risk (P less than 0.001).

Female↗
PubMed1988

Southern African cardiomyopathy in the Republic of South Africa, 1978-1980.

Data on deaths from all cardiovascular conditions (CV) and from cardiomyopathy (MY) are analysed from death certificates for the black populations of the Republic of South Africa. Current rates of death, compared with rates standardized against the notional world standard, suggest that marked increases of CV mortality are to be expected. Regional patterns of MY contrast markedly with the distributions of CV deaths, and Zulu seem less liable to either CV or MY than Xhosa or Tswana. A sample of hospitals also recorded CV and MY for a year among admitted patients, and this morbidity information is compared with the mortality data. Overall it seems likely that increasing numbers of black CV patients pose a threat to the viability of the nation's medical services and warrant stringent surveillance for both economic and humanitarian reasons.

Black People↗
PubMed1985

Lung cancer 1978-1981 in the black peoples of South Africa.

Mortality data on lung cancer among the black populations of South Africa, newly available from the first ever nation-wide enumerations, are analysed for age-specific rates and significant geographical and intertribal variations. This study finds a higher incidence at younger ages than among whites, an urban excess similar to other population groups in South Africa and a higher incidence among the Xhosa than Zulu. It is suggested that an anti-smoking campaign is urgently required among blacks in South Africa.

Adult↗
PubMed1984

Geographical distribution of certain cancers in South Africa, 1968-1972.

The geographical distributions of six major causes of cancer mortality in South Africa have been analysed for three population groups: White, Coloured and Asian. Because of the lack of comparable data, the majority Black population is not included. Geographical patterns are compared and discussed in the light of findings from other countries. In several cases the potential for aetiological follow-up is demonstrated.

Age Factors↗
PubMed1983

Geographical distribution of lung and stomach cancers in South Africa, 1968-1972.

The geographical distribution of lung and stomach cancer among three races in South Africa (Whites, Coloureds and Asians) has been investigated for the years 1968-1972, and the patterns of the occurrence of cases of cancer have been tested stochastically and mapped both separately and together. Information was not available for the Black population. Distinct differences in the distribution of lung and stomach cancer were found. Possible explanations for these differences are discussed.

Black or African American↗
PubMed1983

The Black heart in southern Africa--a geographical view of the future.

The dearth of geographical analyses of heart conditions among the Blacks of southern Africa is contrasted with the well-defined patterns in several countries. By analogy with studies of cancer among Blacks it is argued that similar-order spatial variations of heart-related morbidity are likely to exist, and that knowledge of them is essential in planning services for a health problem of growing urgency.

Africa, Southern↗
PubMed1983

Sudden infant deaths and seasonality in Tasmania, 1970-1976.

Analyses of monthly minimum temperatures and daily minimum temperatures show that significantly more Sudden Infant Deaths and 'pneumonitis' deaths occur in colder conditions in southern Tasmania. Low minimum monthly and low minimum daily temperatures 'explain' part of the observed winter seasonal peak of deaths. However, a sharp change of temperature over 24 hours, either upwards or downwards, is associated with fewer deaths than occurred when little or no change of temperature had been experienced. Utilising the additional data of the Tasmania-wide series it is shown that the winter seasonal effect is especially evident in infants over 3 months of age compared with those aged only 0-3 months, in whom seasonal variation did not occur.

Australia↗
PubMed1982

Cancer of the oesophagus and the use of tobacco and alcoholic beverages in Transkei, 1975-6.

A large questionnaire-based sample survey over a period of 2 years has collected information on tobacco and alcohol use among young and old, male and female respondents in three regions of Transkei selected on the basis of having proved contrasts of incidence experience from oesophageal cancer. Results show significant gradients of social fabric and of customary usage of tobacco and alcohol across the three incidence regions. In particular the concept is supported of a synergistic relationship between tobacco and alcohol when both are used by one individual, with the major role being played by tobacco, especially when smoked in pipes. Stress is also laid on contrasts between old and young on the assumption that dynamic shifts of mortality may be expected to follow as the young of today alter the patterns of intake established by their elders.

Adult↗
PubMed1982

Analyses of cancer incidence in black gold miners from Southern Africa (1964-79).

As an extension of an earlier study covering the 8-year period 1965-71 (t1), the incidence of cancer in black gold miners over a second 8-year period, 1972-79 (t2) has been investigated. The population again totalled 2.9 million man-years of employment, an average of 363,800 men per year. Of the 903 cancers found in t2, primary liver cancer accounted for 45.4%, oesophageal cancer 19.8%, cancer of the respiratory system 11.2% and bladder cancer 2.7%. Analysis of these 4 common cancers by country or region of origin of the miners confirms for the most part the patterns of incidence found in the earlier survey and consolidated rates are therefore presented for the full 16-year period, 1964-79 (t3). The spatial distribution of primary liver cancer within Mozambique and oesphageal cancer within Transkei have been investigated for the periods t1, t2 and t3 and temporal changes of rate have been examined by individual years from 1964 to 1979. The geographical gradient of incidence for cancer of the oesophagus in Transkei has become less marked during the second period of the survey and the crude incidence rate for primary liver cancer in gold miners from Mozambique has continued to drop throughout the period of the survey.

Africa, Southern↗