Notes:
The workers in LCMCo report the rock drill machine, blasting, the hoist mechanism and the crusher machines as the primary sources of noise. The need to use light signals or sign language or to shout is an indication that noise levels are above 85-90 dB most of the time. NIOSH requires hearing protection at the exposure limit of 90dBA over an 8-hour period.[i] The Philippines has similar standards.
An example of noise-induced hearing loss is the hoistman who developed hearing loss in his right ear. He identified the fan and cooling motor as being the noisiest parts of the hoist mechanism. These are located at his right side.
The high prevalence of ruptured eardrum (19.32%) and ear discharge (4.55%) during the physical examination must be further investigated in relation to this.
[i] Mining Safety and Health Administration, New Standards Add Protections for Miners Exposed to Noise, News Release, United States of America, September 1999.