BACKGROUND: Exposure to environmental noise may have a negative impact on a population's mental health. We estimated the prevalence of exposure perception to high environmental noise in the Valencian Community, a region on the Mediterranean coast of Spain, and analysed its association with poor mental health risk, adjusting for demographic, socioeconomic and health status variables. METHODS: Cross-sectional study based on a sample of 5.485 subjects, aged 15 or above, of the 2016 Valencian Community Health Survey. The risk of poor mental health was assessed via Goldberg's questionnaire, a highly standardized self-reported questionnaire designed to screen for general psychological distress in the general population. Noise perception were determined in the home environment based on individuals' responses to the Valencian Survey question about external noise problems. Sociodemographic variables, such as sex, age, level of education, or country of birth, and health variables, such as self-perceived health, or chronic diseases, were also considered. Logistic regression was used to estimate the Odds Ratios and confidence intervals of association between variables according to sex. RESULTS: The prevalence of poor mental health was 26.2% [n = 2665; 95% CI: 24.5-27.9] in men and 33.6% [n = 2820; 95% CI: 31.9-35.3] in women. A total of 7.8% [n = 5485; 95% CI: 6.8-8.8] presented exposure to high noise perception, with no differences according to sex. Being at risk of poor mental health was significantly associated (p < 0.05) with high noise perception after adjusting for the rest of the variables (OR: 2.16 [95% CI: 1.46-3.19] in men; 2.46 [95% CI: 1.72-3.50] in women). CONCLUSIONS Although the prevalence of exposure perception to high noise was not very high, population subgroups presenting high values were detected. High noise perception was related to the risk of poor mental health, regardless of other variables. Poor mental health risk was associated with exposure perception to high noise, other socioeconomic determinants, and health status. Improving noise exposure conditions could reduce the risk of poor mental health.
Humans ; Spain/epidemiology* ; Male ; Female ; Adult ; Middle Aged ; Noise/adverse effects* ; Cross-Sectional Studies ; Young Adult ; Adolescent ; Environmental Exposure/adverse effects* ; Aged ; Mental Health/statistics & numerical data* ; Prevalence ; Mental Disorders/epidemiology* ; Risk Factors

BACKGROUND: Prolonged occupational noise exposure poses potential health risks, but its impact on mitochondrial DNA (mtDNA) damage and methylation patterns remains unclear. METHOD: We recruited 306 factory workers, using average binaural high-frequency hearing thresholds from pure-tone audiometry to assess noise exposure. MtDNA damage was evaluated through mitochondrial DNA copy number (mtDNAcn) and lesion rate, and mtDNA methylation changes were identified via pyrophosphate sequencing. RESULTS: There was a reduction in MT-RNR1 methylation of 4.52% (95% CI: -7.43% to -1.62%) among workers with abnormal hearing, whereas changes in the D-loop region were not statistically significant (β = -2.06%, 95% CI: -4.44% to 0.31%). MtDNAcn showed a negative association with MT-RNR1 methylation (β = -0.95, 95% CI: -1.23 to -0.66), while no significant link was found with D-loop methylation (β = -0.05, 95% CI: -0.58 to 0.48). Mediation analysis indicated a significant increase in mtDNAcn by 10.75 units (95% CI: 3.00 to 21.26) in those with abnormal hearing, with MT-RNR1 methylation mediating 35.9% of this effect. CONCLUSIONS These findings suggest that occupational noise exposure may influence compensatory increases in mtDNA content through altered MT-RNR1 methylation.
Humans ; DNA, Mitochondrial ; DNA Methylation ; Male ; Adult ; Noise, Occupational/adverse effects* ; Middle Aged ; Occupational Exposure/adverse effects* ; Biomarkers/blood* ; Female

OBJECTIVE: To explore the therapeutic effects and underlying mechanisms of Dendrobium officinale (Tiepi Shihu) extract (DOE) on insomnia. METHODS: Forty-two male Sprague-Dawley rats were randomly divided into 6 groups (n=7 per group): normal control, model control, melatonin (MT, 40 mg/kg), and 3-dose DOE (0.25, 0.50, and 1.00 g/kg) groups. Rats were raised in a strong-light (10,000 LUX) and -noise (>80 db) environment (12 h/d) for 16 weeks to induce insomnia, and from week 10 to week 16, MT and DOE were correspondingly administered to rats. The behavior tests including sodium pentobarbital-induced sleep experiment, sucrose preference test, and autonomous activity test were used to evaluate changes in sleep and emotions of rats. The metabolic-related indicators such as blood pressure, blood viscosity, blood glucose, and uric acid in rats were measured. The pathological changes in the cornu ammonis 1 (CA1) region of rat brain were evaluated using hematoxylin and eosin staining and Nissl staining. Additionally, the sleep-related factors gamma-aminobutyric acid (GABA), glutamate (GA), 5-hydroxytryptamine (5-HT), and interleukin-6 (IL-6) were measured using enzyme linked immunosorbent assay. Finally, we screened potential sleep-improving receptors of DOE using polymerase chain reaction (PCR) array and validated the results with quantitative PCR and immunohistochemistry. RESULTS: DOE significantly improved rats' sleep and mood, increased the sodium pentobarbital-induced sleep time and sucrose preference index, and reduced autonomic activity times (P<0.05 or P<0.01). DOE also had a good effect on metabolic abnormalities, significantly reducing triglyceride, blood glucose, blood pressure, and blood viscosity indicators (P<0.05 or P<0.01). DOE significantly increased the GABA content in hippocampus and reduced the GA/GABA ratio and IL-6 level (P<0.05 or P<0.01). In addition, DOE improved the pathological changes such as the disorder of cell arrangement in the hippocampus and the decrease of Nissel bodies. Seven differential genes were screened by PCR array, and the GABA_A receptors (Gabra5, Gabra6, Gabrq) were selected for verification. The results showed that DOE could up-regulate their expressions (P<0.05 or P<0.01). CONCLUSION DOE demonstrated remarkable potential for improving insomnia, which may be through regulating GABA_A receptors expressions and GA/GABA ratio.
Animals ; Dendrobium/chemistry* ; Rats, Sprague-Dawley ; Male ; Sleep Initiation and Maintenance Disorders/blood* ; Plant Extracts/therapeutic use* ; Receptors, GABA-A/metabolism* ; Noise/adverse effects* ; Light/adverse effects* ; gamma-Aminobutyric Acid/metabolism* ; Sleep/drug effects* ; Rats ; Receptors, GABA/metabolism*

Objective:This study aims to investigate the mechanism and potential effects of two exposures to 100 dB sound pressure level（SPL） broadband white noise, with a 14-days interval, on the myelin sheath of the cochlear auditory nerve in mice. The research provides experimental evidence for understanding the pathophysiological processes of noise-induced hearing loss and hidden hearing loss. Methods:Fifteen 6-week-old male C57BL/6J mice with normal hearing thresholds were randomly divided into three groups: a control group（no noise exposure）, a single noise exposure group, and a double noise exposure group. The single noise exposure group was exposed to 100 dB SPL white noise for 2 hours, and ABR thresholds were measured 1 day（P1） and 14 days（P14） after the exposure. The double noise exposure group was exposed to the same conditions of 100 dB SPL white noise for 2 hours, followed by a second identical exposure 14 days later. ABR thresholds were measured 1 day（P15） and 14 days（P28） after the second exposure. The cochleae of all three groups were then collected for immunofluorescence observation of the basilar membrane and transmission electron microscopy to observe changes in the structure of the auditory nerve myelin sheath. Results:In the single noise exposure group, ABR thresholds at all frequencies were significantly elevated compared to the control group at P1. There were no significant changes in ABR thresholds at any frequency at P14. In the double noise exposure group, ABR thresholds at all frequencies were significantly elevated compared to the control group at P15 and P28（P<0.001）. After the first noise exposure, immunofluorescence observation revealed no significant weakening of the auditory nerve myelin sheath signal; transmission electron microscopy showed no significant changes in myelin sheath morphology. However, after the second noise exposure, immunofluorescence observation revealed a weakening of the myelin sheath signal, and transmission electron microscopy showed thinning of the myelin sheath, disruption of the lamellar structure, and separation from the axon, indicating demyelination. Conclusion:Two exposures to 100 dB SPL broadband white noise can lead to damage to the auditory nerve myelin sheath in mice, whereas a single exposure does not cause significant changes.
Animals ; Male ; Myelin Sheath/pathology* ; Mice ; Cochlear Nerve/pathology* ; Mice, Inbred C57BL ; Noise/adverse effects* ; Hearing Loss, Noise-Induced/physiopathology* ; Cochlea ; Evoked Potentials, Auditory, Brain Stem

Noise is one of the most common environmental hazards to which people are exposed,and the exposure to noise can cause not only hearing but also non-hearing damage.Although noise under safety limits may not affect the auditory system,it can cause changes in stress hormone levels,which is harmful to health.However,the current studies about the impact of noise on health mainly focus on the auditory system,and little is known about the relationship between noise and stress hormone levels.Therefore,this paper reviews the studies involving noise exposure and stress hormone levels,aiming to provide ideas for strengthening the prevention and control of noise hazards.
Humans ; Hearing ; Noise/adverse effects* ; Hormones

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*

Alzheimer Disease/genetics* ; Animals ; Apolipoprotein E4/metabolism* ; Gene-Environment Interaction ; Hippocampus/metabolism* ; Male ; Noise/adverse effects* ; Rats

Objective: To explore the association between occupational noise exposure and cardiovascular disease (CVD) risk in a large Chinese population. Methods: In December 2019, the study included 21412 retired participants from the Dongfeng-Tongji Cohort Study at baseline from September 2008 to June 2010, occupational noise exposure was evaluated through workplace noise level and/or the job titles. In a subsample of 8931 subjects, bilateral hearing loss was defined as a pure-tone mean of 25 dB or higher at 0.5, 1 , 2, and 4 kHz in both ears. Logistic regression models were used to explore the association of occupational noise exposure, bilateral hearing loss with 10-year CVD risk. Results: Compared with participants without occupational noise exposure, the 10-year CVD risk was significantly higher for noise exposure duration ≥20 years (OR=1.20, 95%CI:1.01-1.41 , P=0.001) after adjusting for potential confounders. In the sex-specific analysis, the association was only statistically significant in males (OR=2.34, 95%CI: 1.18-4.66, P<0.001) , but not in females (OR=1.15, 95%CI:0.97-1.37, P=0.153). In the subsample analyses, bilateral hearing loss, which was an indicator for exposure to loud noise, was also associated with a higher risk of 10-year CVD (OR= 1.17, 95% CI:1.05-1.44, P <0.001) , especially for participants who were males (OR =1.24, 95% CI:1.07-2.30, P<0.001) , aged equal and over 60 years old (OR=2.30, 95%CI: 1.84-2.88, P<0.001) , and exposed to occupational noise (OR=1.66, 95%CI: 1.02-2.70, P=0.001). Conclusion: Occupational noise exposure may be a risk factor for CVD.
Aged ; Cardiovascular Diseases/epidemiology* ; Cohort Studies ; Female ; Hearing Loss, Bilateral/complications* ; Hearing Loss, Noise-Induced/epidemiology* ; Humans ; Male ; Middle Aged ; Noise, Occupational/adverse effects* ; Occupational Diseases/epidemiology* ; Occupational Exposure/adverse effects*

Objective: To explore the applicability of three different kinds of noise occupational health risk assessment methods to the occupational health risk assessment of noise exposed positions in an automobile foundry enterprise. Methods: In July 2020, the occupational-health risk assessment of noise-exposed positions was conducted by using the Guidelines for risk management of occupational noise hazard (guideline method) , the International Commission on Mining and Metals Guidelines for Occupational Health Risk Assessment (ICMM) method and the Occupational-health risk index method (index method) respectively, and the results were analyzed and compared. Results: Through the occupational health field investigation, the noise exposure level of the enterprise's main workstations was between 80.3 and 94.8 dB (A) , among which the noise of the posts of shaking-sand, cleaning and modeling was greater than 85 dB (A) ; The noise risk of each position was evaluated by the three methods, and the adjustment risk level was between 2 and 5 assessed using the guideline method, between 2 and 3 assessed using the index method, and 5 evaluated using the ICMM model. Conclusion: Each of the three risk assessment methods has its own advantages and disadvantages. The ICMM model has a large difference in value assignment, and values in the results are larger than expected. The evaluation results of the guideline method and the index method are consistent in some positions, there is certain subjectivity in the evaluation using the index method, and the guideline method is more objective.
Automobiles ; Noise, Occupational/adverse effects* ; Occupational Exposure ; Occupational Health ; Risk Assessment/methods*

Objective: To analyze the literature of related research reports on occupational hearing loss (ONIHL) , study the characteristics of the subject and determine the research hotspots. Methods: In December 2020, PubMed database was searched by bibliometrics for ONIHL published in PubMed database from January 1971 to December 2020. Bicomb 2.03 software was used to extract the subject. The publication year, publication country, source magazine and subject words were summarized and analyzed. Results: A total of 1 473 papers were included in this study, and the number of papers was 66 from 1971 to 1980, and 628 from 2011 to 2020, an increase of nearly 10 times. The top three countries were the United States, China and Germany, with 31.5% (464/1473) , 11.5% (171/1473) and 6.2% (91/1473) ; The cross-sectional study was the most applied type; The top five words for 2011-2020: Mental Illness, polymorphism, cardiovascular disease, high frequency hearing impairment and standards and regulations. Conclusion: Susceptibility Genes, Psychological Disorders, Cardiovascular Diseases and Risk Assessment are hot areas in ONIHL at present. Researchers should focus on major fields and grasp future trends as a whole.
Bibliometrics ; Cardiovascular Diseases ; Cross-Sectional Studies ; Hearing Loss, Noise-Induced ; Humans ; Noise, Occupational/adverse effects* ; Occupational Diseases ; PubMed ; United States