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Biomedical subjects

C E Rossiter

Publications and source records attributed to C E Rossiter.

At least 19 recordsLinked to original sources
PubMed1991

Carcinogenicity of the insulation wools: reassessment of the IARC evaluation.

In assessing the health evidence concerning man-made mineral fibers, the chemical composition, surface activity, durability, and size of fibers have to be taken into account. Special-purpose fine glass fibers need to be separated from the insulation wools (glass, rock, and slag wool). The epidemiological evidence is sufficient to conclude that there has been no mesothelioma risk to workers producing or using glass wool, rock wool, or slag wool. The epidemiological studies have been large and powerful, and they show no evidence of a cause-effect relationship between lung cancer and exposure to glass wool, rock wool, or slag wool fibers. There is some evidence of a small cancer hazard attached to the manufacturing process in slag wool plants 20 to 50 years ago, when asbestos was used in some products and other carcinogenic substances were present. However, this hazard is not associated with any index of exposure to slag wool itself. Animal inhalation studies of ordinary insulation wools also show that there is no evidence of hazard associated with exposure to these relatively coarse, soluble fibers. The evidence of carcinogenicity is limited to experiments with special-purpose fine durable glass fibers or experimental fibers, and only when these fibers are injected directly into the pleural or peritoneal cavity. Multiple chronic inhalation studies of these same special-purpose fine glass fibers have not produced evidence of carcinogenicity. It is suggested that the present IARC evaluation of the carcinogenic risk of insulation wools should be revised to Category 3: not classifiable as to carcinogenicity to humans.

Animals↗
PubMed1990

Man-made mineral fibers and lung cancer. Epidemiologic evidence regarding the causal hypothesis.

Reviews of the epidemiologic literature point to a causal connection between lung cancer and exposure to airborne man-made mineral fibers. The present critical re-review starts with the requirements for epidemiologic evidence to be informative regarding a hypothesis on cancer etiology. The previous reviews relate lung cancer mortality to exposure that is too recent to be relevant. The relation to relevant (distant) exposure in the available data involves notable confounding by coexposure to other agents in the work environment, by the lower socioeconomic status of the exposed workers, and possibly by smoking. Moreover, analyses of trends in standardized mortality ratios according to timing and duration of exposure involve a lack of mutual comparability between the ratios. Given these problems, the available evidence is inadequate for testing the causal hypothesis. However, reanalyses of the available data, augmentation of the data with reanalyses, and new studies could eliminate the existing inadequacies.

Air Pollutants, Occupational↗
PubMed1989

Correlation between lung fibre content and disease in East London asbestos factory workers.

The lungs from 36 former workers at an East London asbestos factory dying of asbestos-related disease were compared with lung tissue from 56 matched control patients operated on in East London for carcinoma of the lung. The severity of asbestosis and the presence of pulmonary carcinoma or mesothelioma of the pleura or peritoneum were correlated with an asbestos exposure index and with the type and amount of mineral fibre of the lungs. Asbestosis was associated with far heavier fibre burdens than mesothelioma. Moderate or severe asbestosis was more common among those with carcinoma of the lung than in those with mesothelial tumours. Crocidolite and amosite asbestos were strongly associated with asbestosis, carcinoma of the lung and mesothelial tumours, whereas no such correlation was evident with chrysotile or mullite. It is suggested that greater emphasis should be placed on the biological differences between amphibole and serpentine asbestos fibre.

Aluminum Silicates↗
PubMed1988

A survey into the respiratory effects of prolonged exposure to pulverised fuel ash.

Previous studies of respiratory disorders in workers exposed to pulverised fuel ash (PFA) have been confined to radiological effects that were found to be minimal. The present survey included 268 men (88% of the defined population) with a history of more than 10 years exposure to PFA in six power stations in the south east of England. Respiratory questionnaires with full occupational histories were obtained from all of these subjects, of whom 207 were actively employed and 61 had retired; 243 had lung function tests and 208 had chest x ray examinations. The men were grouped, using their occupational histories, into high, medium, and low exposure categories. Dust concentrations were obtained by personal sampling on a representative sample of men from the three exposure categories. Lung function tests showed that a modest effect on forced vital capacity, vital capacity, forced expiratory volume in one second, peak flow, and gas transfer (DCO) was associated with prolonged heavy exposure to PFA. The men with prolonged heavy exposure also showed higher prevalences of respiratory symptoms. No definite relation between exposure and x ray changes was established. The results of this cross sectional survey indicate that exposures to PFA should not exceed the limits recommended by the Health and Safety Executive for low toxicity dusts.

Adult↗
PubMed1988

Correlation between fibre content of the lung and disease in east London asbestos factory workers.

The lungs from 36 past workers at an east London asbestos factory who had died from asbestos related disease were compared with lung tissue from 56 matched control patients being operated on in east London for carcinoma of the lung, correlating the severity of asbestosis and the presence of pulmonary carcinoma or mesothelioma of the pleura or peritoneum with an asbestos exposure index and type and amount of mineral fibre in the lungs. Asbestosis was associated with far heavier fibre burdens than mesothelioma. There was also a striking difference in the degree of asbestosis between the subjects with mesothelioma and those with carcinoma of the lung, the asbestosis being more severe in the latter. A further finding was that crocidolite and amosite were strongly associated with asbestosis, carcinoma of the lung complicating asbestosis, and mesothelioma, whereas no such correlation was evident with chrysotile or mullite. It is suggested that more emphasis should be placed on the biological differences between amphibole and serpentine asbestos fibre.

Asbestosis↗
PubMed1988

International classification trial of AIA set of 100 radiographs of asbestos workers.

A series of 100 full size radiographs illustrating the range of asbestos related radiographic changes was collected by the Asbestos International Association to provide a demonstration and teaching supplement to the ILO 1980 International Classification of the Radiographic Appearances of Pneumoconioses. Each film was read by 12 experienced readers from ten countries; the readings have been summarised by a median reading, with the range covered by two thirds of the readers. The occupational histories and some relevant clinical information are also available. It is proposed that, in the use of this set, readers should classify each film using the ILO classification rules, particularly without reference to the summary reading or the additional information. Comparing the individual readings by the 12 readers, most of the variation in reading the profusion of small opacities was ascribable only to random variation, with little consistent bias between readers. By contrast, two readers recorded pleural changes much more frequently than their colleagues. This illustrated a major problem with the ILO 1980 Classification. Several others which occurred in this reading trial are also discussed.

Asbestos↗
PubMed1987

Asbestos blues.

Explore the source record for details and available documents.

Asbestos↗
PubMed1983

Erythropoietin and cord blood haemoglobin in the regulation of human fetal erythropoiesis.

Erythropoietin was estimated by radioimmunoassay in serum from 78 cord blood samples, collected in the second and third trimesters in 72 pregnancies. In 43 samples obtained during or after normal pregnancy (from 19 to 42 weeks gestation) erythropoietin levels increased with gestation. Cord blood haemoglobin also increased with gestation, but the rate of increase was less during the last weeks of pregnancy. Erythropoietin levels were similar in the cord blood of infants of the same gestation, whether born vaginally or by caesarean section. The fetus can respond to severe anaemia or hypoxia with increased erythropoietin levels as early as 24 weeks gestation. Elevated erythropoietin levels were found in two out of eight infants born after labour in which there was 'acute' fetal distress, suggesting the presence of unrecognized chronic fetal hypoxia in these pregnancies.

Blood Transfusion, Intrauterine↗
PubMed1982

Development of radiological and clinical evidence of parenchymal fibrosis in men with non-malignant asbestos-related pleural lesions.

After assessment of radiographs taken in 1966, 201 men employed at HM Dockyard, Devonport, were judged to have pleural abnormalities due to exposure to asbestos but to be free from small opacities (ILO U/C 1971 category 1/1 or more), mesothelioma, or bronchial carcinoma. By 1976, 32 of these men had died. Of the survivors, 155 were re-examined to determine the attack rates of parenchymal fibrosis or malignant disease, or both. In 1976, 16 (10.3%) of the survivors had radiographs showing small opacities of category 1/1 or more. When additional clinical criteria had to be satisfied before a diagnosis of parenchymal fibrosis was made the attack rate in the survivors was 4.5%. These attack rates were substantially higher than those observed in a sample of men with no initial pleural abnormality but were unrelated to age, smoking habit, occupation, duration of exposure to asbestos, or type of pleural abnormality. The number of cases of malignant disease was too small to allow any reliable conclusions.

Asbestos↗
PubMed1982

Comparison of independent randomised reading of radiographs with direct progression scoring for assessing change in asbestos-related pulmonary and pleural lesions.

Direct scoring of progression of pleural and parenchymal lesions was compared with change assessed by independent readings to the ILO classification among 155 men from HM Dockyard, Devonport, followed-up for 10 years. For pleural calcification the two methods agreed closely, whereas direct scoring yielded relatively too little progression of small opacities and too much progression of pleural thickening. The choice of method for assessing progression should depend on objectives.

Asbestos↗
PubMed1980

Royal Naval dockyards asbestosis research project: nine-year follow-up study of men exposed to asbestos in Devonport Dockyard.

Progression of asbestos-related disease was assessed in a group of 253 dockyard workers examined in 1966 and 1975. Despite the almost complete protection from exposure to asbestos since 1966, radiographic parenchymal abnormalities increased and occurred more frequently during the next 9 years in those men who had been more heavily exposed to asbestos. Lung function values were lower in those most heavily exposed and were declining at a faster rate than in those with less dust exposure. The most sensitive lung function index was the transfer factor.Those men with persistent crackles in 1966 exhibited a restrictive pattern of lung function, whereas an obstructive pattern was seen in men with wheezes in 1966. The men with irregular small opacities of category 1/1 or more or with diffuse pleural change in 1966 and who survived to 1975 had worse lung functions than any other groups.Progression of disease was greater for smokers than non-smokers, with those who gave up smoking between 1966 and 1975 suffering the greatest changes. This latter group showed most increase in small opacities and included almost all new cases of diffuse pleural changes. They also showed the greatest declines in forced expiratory volume and forced vital capacity.

Asbestos↗
PubMed1980

HM Dockyard, Devonport: 1947 mortality study.

To investigate the effect of occupational exposure to asbestos on mortality, names of all 6292 men born on or after 1 January 1910 and employed as industrial workers in the RN Dockyard, Devonport on 1 January 1947 were submitted to the Office of Population Censuses and Surveys for tracing. Follow-up continued until the end of 1978: over 99% were traced; 3% emigrated; and there were 1043 (17%) deaths. On the basis of the mortality in England and Wales for each five years of age and each five calendar years, the standardized mortality ratio (SMR) was 96. Adjusting the rates for the lower mortality in south-west England, the SMR was 104. No relation was found between SMR and date of birth, and there was only a very slight excess among those more heavily exposed to asbestos. Thirty-one men died with mesothelioma and a further 14 with asbestosis or pulmonary fibrosis. The circulatory disease death rate was slightly raised (SMR = 118), but no more than might have been expected for manual workers. Asbestos-related deaths accounted for at least 4% of all deaths, but probably not many more.

Aged↗
PubMed1979

UK Naval Dockyards asbestosis study: survey of the sample population aged 50-59 years.

As part of a general morbidity study of all civilian employees in the four Royal Naval Dockyards, the clinical, radiological and physiological effects of exposure to asbestos in 1200 men aged 50-59 years were studied in detail. The sample included all men on the Register of Asbestos Workers, one in three of those currently in occupations where intermittent exposure to asbestos may occur, and one in 30 of the remainder. The conclusions are mainly in accord with those of the comprehensive morbidity study of all the civilian dockyard workers, and show that smoking played a large part in increasing prevalence rates of radiographic, clinical, and physiological abnormalities in this population. A sub-group of 39 men, who were working as asbestos laggers or sprayers before 1957, was identified. These men showed much more extensive disease than any other sub-group, yet, even so, the smokers were worse than the non-smokers. Of these smokers, 48% had small opacities of category 1/1 or more, 76% reported that they coughed during the day and 53% had crepitations; forced expiratory volume and transfer factor were also markedly reduced in these 21 smokers. Although asbestos exposure had been intermittent for the majority of the population, the prevalences of pleural thickening, small opacities, current respiratory symptoms and crepitations were shown to be related to duration of exposure to asbestos.

Asbestosis↗