Noise an Environmental Pollutant

The harmful effect of the noise on human health has been known for many decades and it's first harmful effect on the hearing came to be known in the year 1831. According to the nature of the work, this di- sease was called Boiler Maker's deafness.  Noise due to the industrial machineries is one of the main cause of Environmental Poliution, and among the different industreis, Textile industry is the noisiest. As a result, the occupational health department from the start, has established research studies on this sub­ject which is still going on.  The result of a survey conducted at five textile fac­tories in Tehran shows that 25 up to 47 per cent of the workshops cf tr.ese factories have a noise level above T.L.V. (90 dBA for eight hours continuous work during a day for five days per week) and a few within the T.L.V., The effect of such exposures on the hearing is well apparent.  The findings of audiometric examinations show that the hearing loss in first years of work is in 4,000  C. P.S. and as the length of employment increases the hearing loss manifests itself in other frequencies too, the intensity being approximately the same in both ears. As this kind of deafness is a sensorineunal type and no treatment bs been found as yet, application of the below mentioned preventive measures are essen­tial. I. Selection of the workers. 2. Reduction of noise and its source 3. Improvement in architectural designs 4. Use of personal protective devices 5. Periodic Medical examination, including auuiLory check up.