[Impact of occupational noise in the development of arterial hypertension: A survey carried out in a company of electricity production]

Evaluation of the Impact of Noise Pollution on the Workers of the Bottling Line of the Limited Company of Breweries of Guinea (SOBRAGUI)

Introduction

Noise or noise pollution is a phenomenon that causes an auditory sensation considered unpleasant, undesirable, and annoying, which may present a danger to health in general and the auditory system in particular. The objective of this study was to evaluate the impact of noise pollution among workers in a brewery in the city of Conakry.

Patient and methods

This is a prospective descriptive study, of two months' duration (November 11, 2019, to January 10, 2020) carried out in the industrial unit of the Limited Company of Breweries of Guinea (SOBRAGUI). We included all the workers of the company exposed to noise pollution in their workplaces, after their informed consent.

Results

The age of the workers varied between 22 and 70 years, with a mean age of 44.14 ± 8.07 years. We noted a male predominance of 99.22% (n=128) cases. The average duration of exposure was 14.28 ± 6.78 years, with variations ranging from one year to 35 years. Among the auditory disorders, we noted tinnitus in 63.8% (n=74), hypoacusis in 56.9% (n=66), and auditory fatigue in 52.6% (n=61) of cases. These signs were often associated with each other and with other extra-auditory symptoms in the same worker. Audiometry revealed a moderate to severe hearing loss in 13.8% (n=16) and profound deafness in 0.9% (n=1) of cases. The impact of noise pollution on workers' performance was reflected in concentration difficulties in 57.7% (n=67) of cases.

Conclusion

Noise pollution is present in the SOBRAGUI bottling line. It has a negative impact on the health of workers and alters their work performance.

Occupational noise exposure and the prevalence of dyslipidemia in a cross-sectional study

BACKGROUND

Occupational noise exposure was related to cardiovascular disease, of which dyslipidemia was an important inducement. This study investigated the relationship between occupational noise exposure and dyslipidemia.

METHODS

Four hundred ninety-two occupational noise-exposed workers and 664 non-exposed workers were recruited to conduct environmental noise tests and personal occupational physical examinations. A lasso-logistic regression model was used to estimate the relative risk of dyslipidemia. A restricted cubic spline was used to estimate the association between noise exposure years and dyslipidemia after adjusting for potential confounding factors.

RESULTS

A crude association was observed between the occupational noise exposure (75-85 dB(A)) and dyslipidemia. After adjusting for confounding factors, there was a non-linear relationship between noise exposure years and dyslipidemia (P for non-linearity =0.01). Workers exposed to 75-85 dB(A) for 11 to 24.5 years had a higher risk of dyslipidemia than non-exposed workers.

CONCLUSIONS

A positive and non-linear exposure-response relationship was found in workers exposed to 75-85 dB(A) whose exposure years were between 11 and 24.5. Workers had the highest risk of dyslipidemia when exposed for 13.5 years.

Occupational Noise and Hypertension Risk: A Systematic Review and Meta-Analysis

A number of epidemiological studies report an association between occupational noise exposure and arterial hypertension. Existing systematic reviews report conflicting results, so we conducted an updated systematic review with meta-analysis. We registered the review protocol with PROSPERO (registration no.: CRD 42019147923) and searched for observational epidemiological studies in literature databases (Medline, Embase, Scopus, Web of Science). Two independent reviewers screened the titles/abstracts and full texts of the studies. Two reviewers also did the quality assessment and data extraction. Studies without adequate information on recruitment, response, or without a comparison group that was exposed to occupational noise under 80 dB(A) were excluded. The literature search yielded 4583 studies, and 58 studies were found through hand searching. Twenty-four studies were included in the review. The meta-analysis found a pooled effect size (ES) for hypertension (systolic/diastolic blood pressure ≥140/90 mmHg) due to noise exposures ≥80 dB(A) of 1.81 (95% CI 1.51–2.18). There is no substantial risk difference between men and women, but data concerning this question are limited. We found a positive dose-response-relationship: ES = 1.21 (95% CI 0.78–1.87) ≤ 80 dB(A), ES = 1.77 (95% CI 1.36–2.29) > 80–≤85 dB(A), and ES = 3.50 (95% CI 1.56–7.86) > 85–≤90 dB(A). We found high quality of evidence that occupational noise exposure increases the risk of hypertension.