Study of the count-to-mass conversion factor for asbestos fibres in samples collected at the emissions of three industrial plants.
Count-to-mass conversion factors for asbestos fibres in the stack emissions of three industrial plants were calculated. Dust samples deriving from different working processes were collected downstream from the fabric-based filtration systems. Gravimetric measurements were carried out utilizing an X-ray diffraction procedure based on the use of a silver filter that permits the correction for X-ray absorption by the sample. The number of fibres covered by regulations ('Regulated fibres') (F) was counted by phase-contrast optical microscopy (PCOM) on a section of the same filter as had been used for gravimetric measurements. The values of the conversion factors vary widely, ranging from 0.4 x 10(3) to 4.9 x 10(3) fibers per microgram (F microgram -1) according to the working process involved. They are always less than 20 x 10(3) F microgram -1, the value specified in the EEC Directive 217/87 concerning the prevention of asbestos pollution in the environment.
Puledda
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Laboratorio di Igiene Ambientale, Istituto Superiore di Sanità, Rome, Italy.
Marconi
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D000395:Air Pollutants, Occupational / Q000032:analysis*; D001194:Asbestos / Q000032:analysis*; D004391:Dust / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*
D000395:Air Pollutants, Occupational; D004391:Dust; D001194:Asbestos