H. Hori et al., MEASUREMENT OF AIRBORNE CERAMIC FIBERS IN MANUFACTURING AND PROCESSING FACTORIES, The Annals of occupational hygiene, 37(6), 1993, pp. 623-629
Airborne aluminium-silicate ceramic fibre concentrations and fibre siz
es in work environments were measured. Samples were collected from two
factories (A and B), including fibre manufacturing and processing wor
kplaces. In each workplace, five measuring points were chosen for the
stationary sampling. The personal sampling was also carried out simult
aneously. The fibre concentration was determined by counting collected
fibres under the phase contrast optical microscope and the diameter a
nd length distributions were obtained from photographs taken under a s
canning electron microscope. The geometric average concentrations by t
he stationary sampling were 0.10-0.66 fibres per cm(3) (f cm(-3)). The
personal exposure levels for these factories were twice, or more, the
average fibre concentrations by the stationary sampling. The co unt m
edian diameter (CMD) and the count median length (CML) of the fibres i
n the manufact uring workplaces were 1.16 and 14.7 mu m in factory A,
and 0.86 and 12.5 mu m in factory B, respectively. The geometric stand
ard deviation (GSD) of the fibre length was generally larger than that
of the fibre diameter. The values of CMD, CML and GSD by the personal
sampling were almost identical with those by the stationary sampling.