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Noise
is ubiquitous in industry. Continuous exposure to noise levels
above 90 dBA can produce adverse auditory and non-auditory
health effects. Studies carried out by NIOH showed that the
sound pressure levels were very high in various industries,
ranging from 102-114 dBA in textile industries, 93-103 dBA in
pharmaceutical firms, 90-102 dBA in fertilizer plants, 90-119
dBA in oil and natural gas complexes in Bombay High, 60-102
dBA due to road traffic in Ahmedabad city, 90-102 dBA in
surface rail traffic, 70-111 dBA in metro rail, 90-112 dBA for
air traffic. The following health effects were observed due to
excessive noise.
Hearing
acuity of textile weavers aged 25-39 years, exposed to a noise
level of 102-104 dBA was found to be poor. Noise induced
hearing loss (NIHL) at 4000Hz was as high as 30 dB in the age
range 25-29 yrs, 40 dB in the age range 30-34 yrs and 45 dB in
the age range 35-39. The NIHL at 4000Hz is known to be
irreversible.
In
addition to hearing loss, exposure of workers to noise levels
of 90-119 dBA was also found to result in sleep disorders,
mental fatigue, annoyance and reduced alertness,
compared
to those working in a relatively quiet room (60-75 dBA).
Further, it was seen that the speed of performance was
impaired significantly by noise. Adverse effects of noise were
observed in tweezer dexterity with higher degree of
degradation observed at moderately different levels of the
task. Similar observation was also noticeable in two hand
coordination. Reaction time was enhanced under high noise
condition. Certain physiological measures (oral temperature,
pulse rate and skin temperature) were also found to be high in
workers engaged at high noise condition.
The
production data of each weaver collected for at least 15 days
after the weavers were found to have had worn hearing
protection devices (ear plug and ear muff) for 30 successive
days was examined. The results showed that the production of
the weavers wearing ear-muffs aided with ear plugs was
significantly higher than the other weavers. The
findings thus suggest that the weavers with hearing protection
devices had an increased rate of production, parallel to the
increasing degree of protection from noise rendered by the
protective devices.
The
interaction effects of noise and heat on neuromotor based
functions were studied in acoustic chamber. The combined
effect of heat (35°C) and noise (100 dB) caused higher error
rate in card sorting (face value) and decreased accuracy in
reasoning ability.
The
interaction effect of noise and illumination on performance
efficiency examined under six experimental conditions of three
levels of illumination (50, 150 and 300 Lux) and two levels of
noise (70 and 100 dB) revealed significant slowing of response
rate in letter cancellation test in noise condition of 100 dB
and progressive improvement with the gradual rise of
illumination level. The combined effect of noise and
illumination on the accuracy scores reflected performance
decrement under high illumination level (300 Lux) and under
high noise condition (100 dB). The rate of decline in the
accuracy and efficiency of performance in hand precision test
under high illumination level was significantly more
pronounced under noise condition than in the quiet condition
(70 dB)
Asbestosis
Byssinosis
Pneumoconiosis and Other Respiratory Morbidities Among Coal
Miners In India
Noise Pollution and Health Effects
Occupational Exposure to Heavy Metals
Occupational Exposure to Organochlorine Pesticides
Agricultural Ergonomics
Women in Industry: Health and safety
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