5. Results and discussions
Twenty personal samples and one bulk samples have been col-
lected and tested. It was found that the bulk sample contained sil-
ica and 93% of silica existed as quartz. Therefore, only the quartz
was tested during the X-ray analysis.
Twenty respirable samples have been collected and eighteen of
them were valid. They show in Table 2, the results indicated that
none of the measurements exceeded the exposure limits for the
respirable dust concentration (5 mg/m
3
) and seven samples
exceeded the respirable quartz limit (0.05 mg/m
3
). Since there