Magnetic Lung Measurements in Relation to Occupational Exposure in Asbestos Miners and Millers of Quebec

摘要

Fe3O4 particles (magnetic) are often attached to asbestos fibers (non-magnetic) in the primary asbestos industries; therefore, a measurement of Fe3O4 could help determine the amount of asbestos in the lungs of workers in these industries. As a first assessment of this method of determining retained dust, magnetic measurements were made of the amount of Fe3O4 in the lungs of 115 miners and millers of chrysotile asbestos. The performance of these measurements at an industrial site was found to be feasible and practical. A relatively large amount of Fe3O4 was seen in the lungs of those with welding experience, which masked the Fe3O4 contributed by asbestos, therefore this group was considered separately. For the remainder (non-welders), the amount of Fe3O4 was plotted against a total dust exposure index which was available for each individual. The correlation between these quantities was not high, but was statistically significant at the 0.01 level. For the non-smokers within that group, the correlation was higher and the amount of Fe3O4 was relatively greater. These results suggest that the magnetic measurement of a chrysotile miner and miller reflects, at least to some extent, the amount of asbestos in his lung; the scatter could be due to individual differences in deposition and clearance, to which this measurement should be sensitive. These results are also consistent with the possibility that less dust is deposited or retained in smokers than in non-smokers.