Benzene ; adverse effects ; Hearing ; Humans ; Noise, Occupational ; adverse effects

Non-steady state noise has become the main type of workplace noise. Compared with steady state noise, non-steady state noise may cause more serious hearing loss. This paper reviews the new situation of occupational hearing loss caused by non-steady state noise exposure, the overview of international noise exposure assessment standards and new challenges, and the new evidence of non-steady state noise induced hearing loss, so as to provide the basis for the future research of non-steady state noise induced hearing loss.
Auditory Threshold ; Hearing Loss, Noise-Induced ; Humans ; Noise ; Noise, Occupational/adverse effects* ; Occupational Diseases/epidemiology*

Humans ; Noise, Occupational ; adverse effects ; Occupational Exposure ; standards

Adult ; Benzene ; adverse effects ; Hearing ; drug effects ; Humans ; Noise, Occupational ; adverse effects ; Occupational Exposure ; adverse effects

Occupational noise is one of the most common occupational hazards in the workplace. Long-term exposure to occupational noise could not only lead to the damage of the hearing system, but also may cause a certain impact on the cardiovascular system. Studies have shown that occupational noise exposure was positively associated with cardiovascular diseases, including hypertension, coronary heart disease and myocardial infarction. However, the results of studies on occupational noise exposure and stroke are still controversial. This paper reviews the relationship between occupational noise exposure and hypertension, coronary heart disease, stroke, myocardial infarction by summarizing the epidemiological data of domestic and foreign population in recent years. Our study could provide evidence for the design and implementation of well-designed epidemiological and mechanism studies, and the recognition of the role of occupational noise exposure in the occurrence and development of cardiovascular diseases, so as to better protect workers' health.
Cardiovascular Diseases/etiology* ; Hearing Loss, Noise-Induced ; Humans ; Hypertension/etiology* ; Noise, Occupational/adverse effects* ; Occupational Diseases ; Occupational Exposure/adverse effects*

Objective: To explore the change of hearing threshold of workers exposed to noise, establish an individual-based hearing loss early warning model, accurately and differentiated the health of workers exposed to noise. Methods: In September 2019, all physical examination data of 561 workers exposed to noise from an enterprise were collected since their employment. Three indicators of average hearing threshold of the better ear, namely, at high frequency, 4000 Hz and speech frequency, were constructed. The generalized estimating equation (GEE) was used to adjust gender and age and establish the warning model of each indicator. Finally, sensitive indicators and warning models were screened according to AUC and Yoden index. Results: Among the 561 workers exposed to noise, 26 (4.6%) workers had hearing loss. The sensitivity indicators were the average hearing threshold at speech frequency ≥20 dB, high frequency ≥30 dB and 4000 Hz ≥25 dB. The AUC of each index was 0.602, 0.794 and 0.804, and the Youden indexes were 0.204, 0.588 and 0.608, respectively. In GEE of hearing loss warning models, high-frequency hearing threshold ≥20 dB and 4000 Hz hearing threshold ≥25 dB were the optimal models, with AUC of 0.862. Conclusion: Combined with the changes of individual hearing threshold over the years, can accurately assess the risk of individual hearing loss of workers exposed to noise.
Humans ; Hearing Loss, Noise-Induced/diagnosis* ; Noise, Occupational/adverse effects* ; Audiometry ; Deafness ; Employment ; Occupational Exposure/adverse effects* ; Occupational Diseases/diagnosis*

OBJECTIVETo compare the difference of effects on hearing injury between punching machine noise and steady state noise.

METHODSThe subjects of present study were 100 workers, included 38 workers exposed to punching machine noise from forging shops and 62 workers exposed to steady state noise from drawbench or abrasive dust workshops. The individual noise dosimetries were used to detect noise that workers exposed, and cumulative noise exposure (CNE) was then calculated. On the basis of GBZ 49-2007, the worker hearing was tested, and the results were assessed.

RESULTSThere were no differences of CNE between group exposed to punching machine noise and group exposed to steady state noise. The hearing loss rate (55.3%) at high frequency in workers exposed to punching machine noise was significantly higher than that (32.3%) in workers exposed to steady state noise (P < 0.01). CNE and the hearing loss rate at high frequency showed dose-response relationship (P < 0.01).

CONCLUSIONwhen the exposure levels of workers were similar, the hearing injury induced by punching machine noise may be significantly higher than that induced by steady state noise.

OBJECTIVETo investigate the effect of infrasonic field of minesweeper on psychology of minesweeper crews.

METHODSAn experimental ship was selected to conduct infrasonic minesweeping, a control ship of the same type was selected to operate likewise with the infrasound generator turned off, and another group of coast-servicemen was chosen as blank control. Attention-span test, digit memory test, two-digital numbers list and profile of mood states (POMS) were used to test the ship crews and coast-servicemen.

RESULTSThere were no significant differences in psychological parameters between the two ship crews before the experiment. But the scores of two-digit figures list in ship crews were significant lower than that in coast-servicemen, (31.2 +/- 11.8, 36.4 +/- 14.5 respectively vs 45.8 +/- 13.9, P < 0.05). POMS showed that the scores of anger-hostility, fatigue-inertia, and confusion-bewilderment in both ship crew groups [(15.5 +/- 6.4, 18.3 +/- 6.8), (12.1 +/- 5.0,12.3 +/- 4.9), (11.6 +/- 4.4, 12.5 +/- 4.8), respectively] were higher than those in coast-servicemen (13.9 +/- 7.0, 7.6 +/- 4.1, 8.2 +/- 4.3, respectively, P < 0.05 or 0.01), while vigor-activity in experimental group (15.0 +/- 5.9) was lower than that in coast-servicemen (19.7 +/- 4.7). After the experiment, the scores of experimental crews in digit memory test (14.5 +/- 5.0), vigor-activity (12.2 +/- 5.8), fatigue-inertia (15.8 +/- 6.2) were significantly different from those of control crews (17.3 +/- 4.8, 16.5 +/- 4.6, 11.3 +/- 5.1).

CONCLUSIONSThe infrasonic field from minesweeper may injure the crew's psychological health and some neurobehavioral function.

Humans ; Noise, Occupational ; adverse effects ; prevention & control ; Ships

Hearing ; Hearing Loss, Noise-Induced/etiology* ; Humans ; Male ; Manufacturing Industry ; Noise, Occupational/adverse effects* ; Occupational Exposure/adverse effects* ; Surveys and Questionnaires