[Effect of environmental risk factors in occupational noise exposure to noise-induced hearing loss].
OBJECTIVE
To observe the effect of environmental risk factors in occupational noise exposure on hearing loss and find out the susceptible population of noise induced hearing loss (NIHL).


METHODS
A case-control study was designed to study the effect of environmental risk factors on NIHL. 2400 workers exposed to 75 approximately 120 dB noises from an air conditioning factory in southern China served as the subjects. 202 workers were selected from 10% of population with the maximum hearing shift of the left ear to 3000 Hz noises as the NIHL susceptible group while 204 workers from 10% of population with the least hearing shift as the NIHL tolerant group. A questionnaire was designed to carry out an investigation, and an occupational health survey was used to identify the occupational risk factors which might affect the hearing system. The univariate analysis and multivariate analysis were used to observe the effect of environmental risk factors on NIHL.


RESULTS
The results of univariate analysis showed that smoking, alcohol drinking, organic solvent, heavy metal, heat, dust were significantly was associated with NIHL (P < 0.05). Multivariate analysis showed that only heat was associated with NIHL (P < 0.05), and OR value was 1.804 (95% CI: 1.101 approximately 2.958).


CONCLUSIONS
Exposure to heat may be a high risk factor of NIHL.
Liu
Yi-Min
YM
Guangzhou Occupational Disease Prevention & Treatment Centre, Guangzhou 510620, China.
Li
Xu-Dong
XD
Li
Yong-Sheng
YS
Guo
Xiao
X
Xiao
Lv-Wu
LW
Xiao
Qi-Hua
QH
He
Guo-Quan
GQ
Wu
Lin
L
D016022:Case-Control Studies; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000209:etiology*; D006801:Humans; D008297:Male; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D012307:Risk Factors; D011795:Surveys and Questionnaires