| Abstract |
Correlation between Vibration Induced White
Finger and Hearing Loss in Miners: Szanto Cs., et al. Institute
of Public Health Cluj-Napoca, Romania-In the present investigation
age and duration of exposure to vibration and noise were matched
with the intention to confirm the earlier reported difference
in hearing threshold loss in miners with vibration-induced white
finger (VWF) and those without VWF. The case-referent study comprised
264 miners without VWF and 84 miners with VWF. Out of the two
groups were selected 65 pairs, having the same duration of exposure
to vibration and noise (in years) and a maximal difference in
age of 2 yr. The diagnosis of VWF was made after cold provocation
at 10 for 10 min, when the clinical sign appeared: whitening
of the fingers. The values for acceleration of vibration and
noise intensity exceeded the permissible level, when taking measurements
for P-90 type pneumatic hammers used in miners. The mean hearing
threshold level (HTL) was typical for hearing loss induced by
noise, reaching the highest value at 6 kHz both in the case-
and in the reference group. The HTL were lower in those suffering
from VWF than without VWF, for all the frequencies, but significant
differences exist only for 4, 6 and 8 kHz. The mean recovery
rate (RR) for the skin temperature tested at the fingertips after
5, 10 and 15 min indicated significantly high values in the reference
versus cases. The subjects were divided into three groups by
RR of skin temperature 5 min after cold provocation. The miners
having a smaller RR (<0.25) had the lowest HTL; but the subjects
with a prompt RR (>0.90) had hearing thresholds significantly
better at 4, 6 and 8 kHz. For the group with VWF a medium range
correlation between HTL loss and duration of exposure to vibration
at all frequencies was found. The same calculations for the reference
group did not indicate a significant correlation. The effects
of vibration in miners can appear in the hearing organ, far from
the part of the body through which this risk factor enters (the
hand/arm). The correlation between VWF and hearing loss is directly
related to the duration of exposure. |