Greek Mariners And Asbestos Disease Development
One interesting study is called, Asbestos-related chest X-ray changes among greek merchant marine seamen by Emmanuel G. Velonakis MD, Athina Tsorva MD, Anastasia Tzonou DMSc, Prof. Dr. Dimitrios Trichopoulos MD - American Journal of Medicine, Volume 15, Issue 5, pages 511-516 1989. Here is an excerpt: Abstract - One hundred forty-one retired Greek mariners were examined radiologically for asbestos-related lung disease. Thirty-eight (27%) had small opacities classified as ILO category 1/0 or more; 37 (26%) had radiologic evidence of pleural lesions; 17 (12%) had both parenchymal and pleural lesions; and a total of 58 (41%) had one or more radiologic findings of asbestos-related lung disease.
In discriminant analysis, duration of maritime employment was predictive of pleural lesions, but the association was not statistically significant (one-tail, p = 0.16). The prevalence of pleural lesions was also higher among sailors than among officers, and this association was statistically significant (one-tail, p = 0.05). In this group, none of the occupational variables studied (age, duration of maritime employment, and rank) was related to lung fibrosis.
After controlling by multiple regression for mutual confounding effects, suggestive negative associations for the presence of pleural lesions were found with FVC (one-tail, p = 0.13) as well as with FEF25% (one-tail, p = 0.09) and FEF50% (one-tail, p = 0.07). By contrast, no association was found between pulmonary fibrosis and any of the respiratory volumes. The results of this study suggest that mariners may present evidence of asbestos-related disease after many years from onset of exposure on ships.
Another interesting study is called, Investigation and analysis of asbestos fibers and accompanying minerals in biological materials by L. Le Bouffant - Environ Health Perspect. 1974 December; 9: 149153. Here is an excerpt: Abstract - A method is described for isolating asbestos fibers contained in biological tissues. It consists in incinerating the biological material in activated oxygen at 150C, and attacking the ash by 1N HC1 for 18 hr. The residue is then filtered on a membrane covered with a carbon film. Electron microscope examination of the deposit makes it possible to determine fiber concentrations when the weight or volume of primary material is known, and to make size analyses. By x-ray diffraction, the mineralogical nature of the asbestos is determined by comparison with an aluminum reference diagram. For x-ray diffraction, a micromethod is used, with an ash sample of about 10 g.These techniques are used for identifying and counting asbestos fibers in small fragments of lungs or other organs. It was found that asbestos fibers generally go along with other minerals which may be abundant. Most fibers found in lung are less than 5 m long. Counts on lungs of asbestos workers give concentrations often greater than 107 particles per gram of dry tissue. The evolution of inhaled chrysotile seems to be different from that of amphiboles. In the case of pleural mesothelioma, a comparison of fibers within the tumor with fibers in the adjacent parenchyma shows only slight differences in the particle sizes, but marked differences in their nature, with a chrysotile enrichment in the pleural zone. Pleural plaques were analyzed in the same way. After decalcification, many small sized asbestos fibers were found. The same technique is now being used for determining ingested particles. A great number of observations concerning fiber counts, their nature and sizes, and the presence of various clays minerals will be necessary to establish the role of the different factors in the formation of lesions caused by the inhalation or the ingestion of asbestos fibers.
A third study that is interesting is called, Present Status of Asbestos Mining and Related Health - Problems in India A Survey by AL. RAMANATHAN and V. SUBRAMANIAN - School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110 0067, India - Industrial Health 2001, 39, 309315. Here is an excerpt: Abstract: At present in India more than thirty mines are in operation. It produces 2800 tones of asbestos per month (mainly chrysotile and tremolite) and in recent years substantial quantity (-70%) is imported from Canada. The quality of asbestos produced in India is very poor. The mining and milling and other related processes expose the people to cancer and related diseases. Women are more affected by their exposure in processing unit compared to male who are generally working in mines. Direct and indirect employment in asbestos related industry and mine is around 100,000 workers. Latency period (length of the time between exposure and the onset of diseases) in India is estimated to be 2037 yr. The causes for lung and breathing problem are mainly due to obsolete technology and direct contact with the asbestos products without proper precaution, because in India asbestos are sold without statutory warning. This paper reviews health effects (such as fibrosis, sequelae, bronchogenic cancer, and malignant mesothelioma) on the Indian mine workers caused due to asbestos mining related activities with respect to their present day condition.
We all owe a debt of gratitude to these fine researchers for their important work. If you found any of these excerpts helpful, please read the studies in their entirety.
In discriminant analysis, duration of maritime employment was predictive of pleural lesions, but the association was not statistically significant (one-tail, p = 0.16). The prevalence of pleural lesions was also higher among sailors than among officers, and this association was statistically significant (one-tail, p = 0.05). In this group, none of the occupational variables studied (age, duration of maritime employment, and rank) was related to lung fibrosis.
After controlling by multiple regression for mutual confounding effects, suggestive negative associations for the presence of pleural lesions were found with FVC (one-tail, p = 0.13) as well as with FEF25% (one-tail, p = 0.09) and FEF50% (one-tail, p = 0.07). By contrast, no association was found between pulmonary fibrosis and any of the respiratory volumes. The results of this study suggest that mariners may present evidence of asbestos-related disease after many years from onset of exposure on ships.
Another interesting study is called, Investigation and analysis of asbestos fibers and accompanying minerals in biological materials by L. Le Bouffant - Environ Health Perspect. 1974 December; 9: 149153. Here is an excerpt: Abstract - A method is described for isolating asbestos fibers contained in biological tissues. It consists in incinerating the biological material in activated oxygen at 150C, and attacking the ash by 1N HC1 for 18 hr. The residue is then filtered on a membrane covered with a carbon film. Electron microscope examination of the deposit makes it possible to determine fiber concentrations when the weight or volume of primary material is known, and to make size analyses. By x-ray diffraction, the mineralogical nature of the asbestos is determined by comparison with an aluminum reference diagram. For x-ray diffraction, a micromethod is used, with an ash sample of about 10 g.These techniques are used for identifying and counting asbestos fibers in small fragments of lungs or other organs. It was found that asbestos fibers generally go along with other minerals which may be abundant. Most fibers found in lung are less than 5 m long. Counts on lungs of asbestos workers give concentrations often greater than 107 particles per gram of dry tissue. The evolution of inhaled chrysotile seems to be different from that of amphiboles. In the case of pleural mesothelioma, a comparison of fibers within the tumor with fibers in the adjacent parenchyma shows only slight differences in the particle sizes, but marked differences in their nature, with a chrysotile enrichment in the pleural zone. Pleural plaques were analyzed in the same way. After decalcification, many small sized asbestos fibers were found. The same technique is now being used for determining ingested particles. A great number of observations concerning fiber counts, their nature and sizes, and the presence of various clays minerals will be necessary to establish the role of the different factors in the formation of lesions caused by the inhalation or the ingestion of asbestos fibers.
A third study that is interesting is called, Present Status of Asbestos Mining and Related Health - Problems in India A Survey by AL. RAMANATHAN and V. SUBRAMANIAN - School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110 0067, India - Industrial Health 2001, 39, 309315. Here is an excerpt: Abstract: At present in India more than thirty mines are in operation. It produces 2800 tones of asbestos per month (mainly chrysotile and tremolite) and in recent years substantial quantity (-70%) is imported from Canada. The quality of asbestos produced in India is very poor. The mining and milling and other related processes expose the people to cancer and related diseases. Women are more affected by their exposure in processing unit compared to male who are generally working in mines. Direct and indirect employment in asbestos related industry and mine is around 100,000 workers. Latency period (length of the time between exposure and the onset of diseases) in India is estimated to be 2037 yr. The causes for lung and breathing problem are mainly due to obsolete technology and direct contact with the asbestos products without proper precaution, because in India asbestos are sold without statutory warning. This paper reviews health effects (such as fibrosis, sequelae, bronchogenic cancer, and malignant mesothelioma) on the Indian mine workers caused due to asbestos mining related activities with respect to their present day condition.
We all owe a debt of gratitude to these fine researchers for their important work. If you found any of these excerpts helpful, please read the studies in their entirety.
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