A study on the relationship between hearing impairment and blood pressure and hypertension in workers occupationally exposed to noise / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the correlation between noise and blood pressure and/or hypertension, and its age characteristic.</p><p><b>METHODS</b>The pure tone audiometric and blood pressure examinations were performed in 14537 workers from 157 factories. Hearing impairment was used as a surrogate indicator of cumulated noise exposure. The associations of hearing impairment and duration of noise exposure with blood pressure and hypertension were analyzed respectively after age and gender stratification.</p><p><b>RESULTS</b>Most of the objects were males (81.2%), younger than 35 years old (77.8%), and the duration of exposure to noise was less than 5 years (73.6%). The prevalence of hearing impairment in males was significantly higher than that in males, and increased with age and duration of noise exposure. Only in males with age younger than 35 years old, the systolic and diastolic blood pressures of subjects with sensorineural hearing loss significantly enhanced, and the diastolic blood pressure and prevalence of hypertension increased with duration of noise exposure. The risk of hypertension in males with sensorineural hearing loss significantly increased, the odds ratios in subjects with age younger than 35 years old and with age older than 35 years old were 3.0 (95%CI: 1.5 ∼ 6.1) and 2.1 (95%CI: 1.2 ∼ 3.4), respectively.</p><p><b>CONCLUSION</b>The severe hearing impairment induced by noise was associated with hypertension. It is suggested that people should pay attention to the effects of noise on hypertension in young workers.</p>

Effect of environmental risk factors in occupational noise exposure to noise-induced hearing loss / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>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).</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>Exposure to heat may be a high risk factor of NIHL.</p>