Investigation of screening methods for identifying population susceptible to noise-induced hearing loss / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the screening methods for identifying the populations susceptible and resistant to noise-induced hearing loss (NIHL) and to provide a reference for future research.</p><p><b>METHODS</b>Workers who were exposed to 75 ∼ 120 dB noise in enterprises were included in the study. Field investigation of occupational health was conducted; workers' basic information and data on hearing threshold levels were collected. Paired chi-square test was used to compare each two of three screening methods, which were used at home and abroad to identify noise-susceptible and noise-sensitive populations, in terms of noise exposure level, general information, and noise-induced hearing threshold shift.</p><p><b>RESULTS</b>There were no significant differences in the noise exposure level, basic information, and left and right ears' hearing threshold levels of noise-susceptible and noise-sensitive populations between each two of the three screening methods (P > 0.05), according to the paired chi-square test. However, high-frequency hearing threshold had statistically significant difference among the three methods. As a whole, methods B and C were superior to method A.</p><p><b>CONCLUSION</b>The workers in China are younger than before, with more awareness of self-protection, and individual protection is enhanced in them. Currently, method B is more suitable for screening out the population susceptible to NIHL in China.</p>

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>

Analysis of the situation of occupational health surveillance and the morbidity of occupational diseases in Guangzhou / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To analyze the situation of occupational health surveillance and the characteristics of occupational diseases in Guangzhou.</p><p><b>METHODS</b>The situation of occupational health surveillance and the morbidity of occupational diseases were studied retrospectively by use of the physical examination data collected from the labour hygienic reports of the city from 1993 to 2002. The data were divided into two groups: the first group from 1993 to 1997, and the second from 1998 to 2002.</p><p><b>RESULTS</b>Annual average of occupational health examination in the past 10 years was over 75%. The data in the second group (1998 - 2002) showed that the number of hearing loss observed subjects, noise surveilled personnels, dust and chemicals contraindicated personnels were significantly higher than those in the 1st group (P < 0.01). The morbidity of chronic occupational disease newly occurred was 91 cases in lst group, and 181 cases in 2nd group (P < 0.05), in which the incidence of chemical poisoning and noise induced hearing loss increased significantly but that of pneumoconiosis between two groups was not significantly different (P > 0.05). In the past 10 years, 581 cases of occupational diseases were diagnosed, of which, 309 cases (53.18%) were acute poisonings, while 272 cases (46.82%) were chronic occupational diseases. Pneumoconiosis, lead and benzene poisoning were common in chronic occupational diseases (16.70%, 16.87% respectively). With the passage of time, the incidence ages of pneumoconiosis, chemical poisoning and total occupational diseases tended towards younger. The difference was statistically significant (P < 0.01)</p><p><b>CONCLUSION</b>A normal system for occupational health surveillance has been developed in Guangzhou. Detectable rates in focused surveillance and contraindication have been obviously increasing. The incidence of occupational disease (mainly including acute occupational poisoning, pneumoconiosis, lead and benzene poisonings) is also going up. The incidence age of chronic occupational diseases tends to be younger accompanied with a shorter work history.</p>