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>

Effects of occupational noise exposure on norepinephrine in peripheral blood and cardiovascular system / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of noise on bioactivity of norepinephrine (NE) and cardiovascular system.</p><p><b>METHODS</b>A total of 130 workers exposed to the occupational noise in one enterprise were selected as noise exposure group, and 134 workers not exposed to the occupational noise and other poisons served as control group. Fasting venous blood was drawn to determine the content of NE in peripheral blood with ELISA. According to Occupational Health Surveillance Manage regulations, the occupational noise exposures crowd was examined.</p><p><b>RESULTS</b>The average of NE in exposure group was (0.1387 +/- 0.099) ng/ml, and (0.1019 +/- 0.080) ng/ml in control group. There was significant difference in NE between exposure and control group. There was significant difference in the detection rate of BP, HR and ECG between exposure and control group.</p><p><b>CONCLUSION</b>The occupation noise can increase the NE in peripheral blood, and maybe affects the cardiovascular system in this way.</p>