[Types and dimensions of mineral fibers in the atmosphere and from lungs of residents in the urban area].
OBJECTIVE
The objective of this study was to estimate the types and origin of the mineral fibers in the lungs of residents in the urban area.


METHODS
Mineral fibers in the atmosphere from 21 urban areas were analyzed by direct transfer-analytical transmission electron microscopy (ATEM). Lung tissues of 36 urban residents without occupational asbestos exposure were also analyzed by ATEM after low temperature ashing. Measurement of dimensions of all types of mineral fibers, identification of asbestos, and classification of nonasbestos fibers according to the combination of main elements were carried out.


RESULTS
1. Chrysotile, amosite, actinolite, tremolite and 11 types of nonasbestos fibers were found in both the lung tissues and the atmospheric samples. The fibers, mainly composed of Al and Si, contributed 16.3% and 62.3% of the atmospheric samples and lung tissues respectively. On the other hand, the proportion of the fibers mainly composed of S and Ca were 43.7% and 0.0% in the atmosphere and lung tissues respectively. Those fibers mainly composed of P and Fe were 0.4% and 18.4% in the atmosphere and lung tissues respectively. 2. Fifteen types of nonasbestos fibers were found exclusively in the atmosphere. The average proportions for ten of these were less than 0.5% each. 3. Crocidolite was found exclusively in the lung tissues. 4. No significant difference in the geometric mean of length and diameter of asbestos was found between the atmospheric samples and lung tissues. Some types of nonasbestos fibers had significantly larger length and diameter in the atmospheres than in the lung tissues (p < 0.01).


CONCLUSIONS
The results suggest that mineral fibers found in lung tissues could be classified into three groups on the basis of their behavior. 1) Some fibers, such as amphibole asbestos and fibers composed of Al and Si, are inhaled from the atmosphere and remain in the lung tissues for a long time. 2) Some fibers, such as those composed of S and Ca, are inhaled from the atmosphere and eliminated from the lung tissues within a relatively short time. 3) Some fibers found more in the lung tissues than in the atmospheres, such as those composed of P and Fe, are suspected to be generated in the lungs.
Sakai
K
K
Nagoya City Public Health Research Institute.
Hisanaga
N
N
Shibata
E
E
Kojima
A
A
Takeuchi
Y
Y
D000393:Air Pollutants / Q000032:analysis*; D005260:Female; D006801:Humans; D007564:Japan; D008168:Lung / Q000737:chemistry*; D008297:Male; D019016:Mineral Fibers / Q000032:analysis*; D014504:Urban Health
D000393:Air Pollutants; D019016:Mineral Fibers