[Effects of exposure to noise in oil-drilling well sites on cochlea in guinea pigs].
OBJECTIVE
To prevent from hearing damage caused by noise in the sites with drilling wells.


METHODS
Intensity and spectrum of the noise produced in the sites with drilling wells were measured and analyzed. Measures, such as sound insulation, vibration damping and changing layouts of the drilling platform, were adopted, and electrocochleography (ECochG) and scanning electron microscopy were used to observe the effects of noise in the sites where drilling wells located on the hearing organs in guinea pigs after exposure.


RESULTS
There was no significant difference in APN1 latency of ECochG before and after exposure to noise. There were significant difference in hearing threshold values between the groups in a room with sound isolation, in moving status and beside the diesel engine, and no significant difference in those between the groups placed one meter horizontally and vertically away from the diesel engine on the drilling platform. Damage to hairy cell under scanning electron microscope was more severe in the guinea pigs placed beside the diesel engine and at the drilling well platform, with inclination and exfoliation of static pili of outer hairy cells, especially in the second and third lines, and part exfoliation of inner hairy cell. Hairy cells of the guinea pigs in a room with sound insulation and in moving status were basically normal. Inclination of hairy cells only could be seen in the third line.


CONCLUSIONS
Animal experiments indicated that the measures mentioned above are effective and should be applied widely for preventing from hearing damage.
D000818:Animals; D001300:Audiometry, Evoked Response; D003051:Cochlea / Q000503:physiopathology*; D005260:Female; D006168:Guinea Pigs; D006317:Hearing Loss, Noise-Induced / Q000517:prevention & control*; D008297:Male; D008906:Mining; D009623:Noise, Occupational / Q000009:adverse effects*; D016273:Occupational Exposure / Q000517:prevention & control; D010578:Petroleum; D011897:Random Allocation