Are children more vulnerable to mesothelioma than adults? A comparison of mesothelioma risk among children and adults exposed non-occupationally to blue asbestos at Wittenoom.

Objectives: The presence of asbestos in public buildings is a legacy of past asbestos use in many developed countries. Of particular concern is the amount and current condition in schools and the vulnerability of children to mesothelioma. Our aim was to compare the risk of mesothelioma between those exposed to blue asbestos as children and as adults at Wittenoom.

Familial aggregation of malignant mesothelioma in former workers and residents of Wittenoom, Western Australia.

Clustering of cases of malignant mesothelioma within families has often been observed, but disentangling genetic and exposure effects has not been done. Former workers and residents exposed to crocidolite at Wittenoom, Western Australia, where many families shared exposure to asbestos, have had high rates of mesothelioma. Our study aimed to estimate the additional risk of mesothelioma in relatives, after allowance for common exposure to crocidolite.

Retinol supplementation and mesothelioma incidence in workers earlier exposed to blue asbestos (Crocidolite) at Wittenoom, Western Australia.

Owing to the high rates of malignant mesothelioma in workers exposed to crocidolite earlier at Wittenoom and evidence of protection against cancer by vitamin A, a population-based cancer prevention programme providing retinol supplements (25 000 IU/day) was commenced in 1990. The former workers at Wittenoom known to be alive and living in Western Australia in June 1990 constitute the study population. The participants were classified into two groups: those who received supplemental retinol (intervention group) and those who received none (comparison group).

Prediction of mesothelioma and lung cancer in a cohort of asbestos exposed workers.

Background: Several papers have reported state-wide projections of mesothelioma deaths, but few have computed these predictions in selected exposed groups.

Objective: To predict the future deaths attributable to asbestos in a cohort of railway rolling stock workers.

Methods: The future mortality of the 1,146 living workers has been computed in term of individual probability of dying for three different risks: baseline mortality, lung cancer excess, mesothelioma mortality.

Mesothelioma and asbestos.

The current state of knowledge concerning mesothelioma risk estimates is reviewed. Estimates of the risk of mesothelioma exist for the commercial asbestos fiber types chrysotile, amosite and crocidolite. Data also exist on which to assess risks for winchite (sodic tremolite) and anthophyllite asbestos.

An overview of the risk of lung cancer in relation to exposure to asbestos and of taconite miners.

Exposure-response relationships between the relative risk of lung cancer and quantitative measures of exposure to asbestos are available from a number of epidemiological studies. Meta-analyses of these relationships have been published by Lash et al. (1997) [Lash, T.

Projected mesothelioma incidence in men in New South Wales.

Objectives: Based on observed numbers of incident mesotheliomas since 1972, to predict future numbers in men in New South Wales.

Methods: The incidence of mesothelioma was modelled in two ways. First by using an age/birth cohort model, and second by using a model based on potential exposure to asbestos in terms of age and calendar year.

Age and sex differences in malignant mesothelioma after residential exposure to blue asbestos (crocidolite).

Background: Blue asbestos was mined and milled at Wittenoom, Western Australia, from 1943 until 1966. Various public records were used to establish a cohort of residents of the nearby township. Mine tailings were distributed throughout the town.

Relative risk and acceleration in lung cancer.

For a substance that increases the relative risk of disease, it does not necessarily follow that the proportion of cases due to exposure to the substance is the same as the attributable fraction in the exposed. An alternative explanation is that the substance has accelerated the occurrence of disease and, therefore, played a role in all cases. When the incidence of disease with time follows the Weibull distribution, it is well known that the proportional hazards model and the accelerated failure time model are equivalent.

Comparing the part with the whole: should overlap be ignored in public health measures?

Background: In public health, health outcomes such as cancer incidence or mortality of subgroups are often compared with health outcomes of the whole population. Our objective was to explore the effect of overlap that occurs in such comparisons and to develop a correction factor to adjust the test statistics and confidence intervals to allow for the effect in situations where the full data are not available.

Method: The standard error of a difference between a statistic calculated for a subgroup and for the whole population was derived theoretically both ignoring and allowing for overlap.

Nonuniform risk of bloodstream infection with increasing central venous catheter-days.

Objective: To determine whether the conventional rate for central venous catheter (CVC)-associated bloodstream infection (BSI) accurately reflects risk for patients exposed for a variety of in situ periods.

Patients And Methods: Intensive care unit patients (n = 1,375) were monitored for 7,467 CVC-days. They were monitored until catheter removal, until diagnosis of CVC-associated BSI, or for 24 hours after discharge.

A randomized controlled trial of cyclosporine withdrawal in renal-transplant recipients: 15-year results.

Background: In renal transplantation, the immunosuppressive efficacy of cyclosporine is counterbalanced by its nephrotoxicity. Although cyclosporine improves short-term graft survival, its long-term effects are unclear.

Methods: Recipients of first cadaver renal transplants were randomized into three groups between 1983 and 1986: azathioprine and prednisolone alone (AP, n = 158), long term cyclosporine alone (Cy, n = 166), and short-term cyclosporine followed by azathioprine and prednisolone (CyAP, n = 165).

Silicosis and lung cancer: a mortality study of compensated men with silicosis in New South Wales, Australia.

Background: Lung cancer mortality has been found to be in excess in several groups with silicosis, but allowance for smoking was not always possible. We investigated the lung cancer mortality in men with silicosis in New South Wales, Australia, who were compensated, making allowance for smoking habits.

Methods: A mortality study of 1467 men with silicosis in New South Wales who were compensated was carried out comparing observed mortality with that expected from the New South Wales death rates adjusting for age and period.

Health impacts of pesticide exposure in a cohort of outdoor workers.

We compared mortality of 1,999 outdoor staff working as part of an insecticide application program during 1935-1996 with that of 1,984 outdoor workers not occupationally exposed to insecticides, and with the Australian population. Surviving subjects also completed a morbidity questionnaire. Mortality was significantly higher in both exposed and control subjects compared with the Australian population.

Differences in muscle fiber growth in slow-twitch muscles of the forelimb and hindlimb of the rat: role of the pituitary and food intake.

This investigation tested the hypothesis that differences in the growth of fore- and hindlimb muscles in the rat are regulated by the pituitary and food intake. Using morphometric techniques, the growth of muscle fibers was compared in two slow-twitch muscles, the flexor carpi ulnaris (FCU) of the forelimb, and the soleus of the hindlimb, in male Wistar rats fed ad libitum, food restricted (FR) or hypophysectomized (hypox) from age 60 days. Growth was defined as an increase in fiber diameter and/or type 1 fiber percentage.

Socio-economic mortality differentials in Sydney over a quarter of a century, 1970-94.

Objective: To examine trends in socio-economic differentials in all-cause mortality in Sydney over a 25-year period (1970-94).

Methods: Five measures of single indicators (two for occupation, two for education and one for income) and a composite measure of socio-economic disadvantage based on Census data (the Australian Bureau of Statistics' Index of Relative Socio-Economic Disadvantage) were used as indicators of socio-economic status by local govemment area. The relationship between mortality and socio-economic status was examined using quintiles based on these six measures of socio-economic status.

Analytic methods for comparing two dichotomous screening or diagnostic tests applied to two populations of differing disease prevalence when individuals negative on both tests are unverified.

Two dichotomous screening tests may be compared by applying both tests to all members of a sampled population. For individuals with a positive result on either test the disease status may be verified by a reference standard, but for individuals negative on both tests the disease status may be unverified because the probability of disease is so low that further investigation is costly, unacceptable and perhaps unethical. If the tests have been applied to samples from two populations which have different disease prevalences then unbiased estimates of the true positive and false positive rates of each test, the prevalences in the two populations, and two parameters representing dependence between the two tests can be estimated using maximum likelihood methods.