Effects of occupational exposure to noise and dust on blood pressure in Chinese industrial workers

Long-Term Exposure to Dust and Noise Can Increase the Risk of Hypertension-A Population Based, Cross-sectional Study

OBJECTIVE

The aim of the study is to assess whether occupational groups exposed to dust and noise increase their risk of developing hypertension and to identify associated risk factors.

METHODS

Logistic regression analysis was used to analyze the influence of exposure factors on the occurrence of hypertension, and confounding factors were adjusted to identify independent effects. Stratified analysis and smoothed curve fitting were used to explore the effects in different populations.

RESULTS

Combined dust + noise exposure significantly increased the risk of hypertension in workers (model 1: odds ratio [OR], 2.75; model 2: OR, 2.66; model 3: OR, 2.85). Further analysis showed that when exposed to dust and noise for more than 17 years, the risk of hypertension increased by 15%.

CONCLUSIONS

The combined exposure of dust and noise significantly increases the risk of hypertension among occupational groups, especially among workers who have worked for more than 17 years.

Ensemble filters with harmonize PSO-SVM algorithm for optimal hearing disorder prediction

Discovering a hearing disorder at an earlier intervention is critical for reducing the effects of hearing loss and the approaches to increase the remaining hearing ability can be implemented to achieve the successful development of human communication. Recently, the explosive dataset features have increased the complexity for audiologists to decide the proper treatment for the patient. In most cases, data with irrelevant features and improper classifier parameters causes a crucial influence on the audiometry system in terms of accuracy. This is due to the dependent processes of these two, where the classification accuracy performance could be worsened if both processes are conducted independently. Although the filter algorithm is capable of eliminating irrelevant features, it still lacks the ability to consider feature reliance and results in a poor selection of significant features. Improper kernel parameter settings may also contribute to poor accuracy performance. In this paper, an ensemble filters feature selection based on Information Gain (IG), Gain Ratio (GR), Chi-squared (CS), and Relief-F (RF) with harmonize optimization of Particle Swarm Optimization (PSO) and Support Vector Machine (SVM) is presented to mitigate these problems. Ensemble filters are utilized so that the initial top dominant features relevant for classification can be considered. Then, PSO and SVM are optimized simultaneously to achieve the optimal solution. The results on a standard Audiology dataset show that the proposed method produces 96.50% accuracy with optimal solution compared to classical SVM, which signifies the proposed method is effective in handling high dimensional data for hearing disorder prediction.

Types, sources, socioeconomic impacts, and control strategies of environmental noise: a review

Noise exposure has reached an alarming degree over the years because of rapid growth in the industry, transportation, and urbanization. Therefore, it is a dire need to provide awareness of the sources and mitigation strategies of noise, and to highlight the health, and socio-economic impacts of noise. A few research studies have documented this emerging issue; however, there is no comprehensive document describing all types of noise, their impacts on living organisms, and control strategies. This review article summarizes the sources of noise; their effects on industrial workers, citizens, and animals; and the value of property in noisy areas. The plethora of literature is showing an increased level of noise in various cities of the world, which have various health consequences such as high blood pressure, insomnia, nausea, heart attack, exhaustion, dizziness, headache, and triggered hearing loss. Apart from humans, noise also affects animal habitat, preying, and reproduction ability; increases heart rate and hearing loss to even death and loss in property value; and impairs the hospital environment. Finally, we have discussed the possible strategies to mitigate the noise problem, policy statements, and regulations to be followed, with future research directions based on the identified research gaps.

Occupational risk factors for hypertension

The identification and characterization of the modifiable risk factors of hypertension is of great value for public health and clinical medicine to achieve primary prevention. A large amount of literature on the effects of occupational factors on blood pressure and hypertension has been published. In this review, I summarize current evidence regarding the role of occupational factors in hypertension. The results of this review suggest that there is sufficient evidence to support the association between increased risk of hypertension and job stress, shift work, occupational lead exposure, and noise exposure. The association of hypertension with physical inactivity, sedentary behavior, and occupational exposure to mercury, arsenic, cadmium, or carbon disulfide remains inconclusive, although several studies have reported this finding. This review will serve as a step toward future research and provide baseline information for developing strategic interventions to prevent hypertension in the working population.

Investigating the effects of occupational and environmental noise on cardiovascular diseases: a systematic review and meta-analysis

The present study aimed to use a meta-analysis to investigate the relationship between occupational and non-occupational noise exposure expressed in various studies with cardiovascular disease. This is a systematic review and meta-analysis study based on PRISMA checklist. In this study, the researchers searched five international databases of Medline/PubMed, Embase, Scopus, ISI/web of knowledge, and Google Scholar. Search keywords included two categories noise and noise pollution, cardiovascular disease, and hypertension. The Joanna Briggs Institute checklist was used to review and control the quality of the articles. After all screening stage 139 articles entered the final analysis. The results show that except for East African environmental studies and workplace studies in East Asia, Western Asia, and Northern Europe, there was a significant association between noise exposure and cardiovascular disease. Also, there was a significant difference between the intensity of sound and blood pressure in workers (OR = 1.28, CI 95%: 1.15-1.42, P < 0.001). Based on the results of environmental noise, there was a significant difference between ambient noise intensity and blood pressure (OR = 1.55, CI 95%: 1.53-1.57, P < 0.001). It can be concluded that it is very important to study and identify jobs or living environments with less than the recommended noise level and in addition to hearing aids that occur in over-standard exposures, such as cardiovascular disease.

Evaluating the Effects of Noise Pollution on the Levels of Blood Cortisol, Testosterone, and Thyroid in Male Wistar Rats

Background: Noise pollution is a global problem causing changes in the secretion of various hormones and consequently affecting social well-being and quality of life in cities. Objectives: This study aimed to investigate the effect of noise pollution on the levels of testosterone, thyroid, and cortisol hormones in male rats. Methods: In this experimental study, a total of 70 male Wistar rats (200 - 250 g) were randomly assigned into one control and six experimental groups, with 10 rats in each group. Experimental groups were exposed to noise with different intensity (dB) and time (min) as follows: (I) 60 dB, 30 min; (II) 60 dB, 60 min; (III) 85 dB, 30 min; (IV) 85 dB, 60 min; (V) 110 dB, 30 min; (VI) 110 dB, 60 min; (VII) controls. Animals in the experimental groups were exposed to noise in an acoustic chamber designed for this purpose for 50 days. The Noise.exe software was used to generate noise, and the sound level meter (model TES 1358) was used to determine the accuracy of the intensity and frequency of sound. To determine plasma levels of the hormones, appropriate research and commercial kits were used, which were based on the ELISA method. To determine the concentration of hormones other than TSH, human assay kits were used. All statistical tests were performed in SPSS software version 21. Results: Serum levels of cortisol in the 110-dB (30 and 60 min), 65-dB (60 min), and 85-dB (60 min) groups were significantly higher than the control group (P ≤ 0.05). Also, cortisol levels in the 65-dB and 85-dB (30 minutes) groups were higher than the control group; however, the increase was not significant (P > 0.05). The levels of T4, T3, and TSH in the 60-dB and 85-dB groups were significantly lower than in the control group (P ≤ 0.05). The serum levels of T4, T3, and TSH hormones in the 110-dB group were insignificantly lower than the control group (P > 0.05). The serum level of testosterone in the 110-dB group was significantly lower than the control group (P ≤ 0.05). The mean serum levels of testosterone in the 65-dB and 85-dB groups were insignificantly lower than the control group (P > 0.05). Conclusions: Based on this study, exposure to noise pollution increased cortisol secretion and decreased T4, T3, TSH, and testosterone levels in rats. As this hormonal imbalance may create direct and indirect effects, studies and strategies are recommended to control the imbalance of hormones in the polluted environments.

Weighing and modelling factors influencing serum cortisol and melatonin concentration among workers that are exposed to various sound pressure levels using neural network algorithm: An empirical study

BACKGROUND

Noise is one of the most common harmful agents in the workplace. Exposure to excessive noise can lead to complications such as cardiovascular disorders, disturbance of body hormones' rhythm and hearing loss. This study aimed at weighing and modelling factors influencing serum cortisol and melatonin concentrations of workers that are exposed to various sound pressure levels using neural network algorithm.

METHODOLOGY

A case-control design was adopted in the current research. The required data were collected from 75 industrial and mining firm staff members. They were assigned to three groups with equal sample sizes (25 workers). In developing the conceptual model in regard to variables that may affect workers' serum cortisol and melatonin concentration, SPL, age, weight, and height were included. The influence of SPL on serum cortisol concentration as assessed in the three shifts. Moreover, radioimmunoassay (RIA) was utilized to assess serum cortisol and melatonin concentrations. Neural network algorithm was subsequently exploited to weigh and model predictor factors. IBM SPSS Modeler 18.0 was the software program used for data analysis.

RESULTS

The average cortisol concentration values for administrative, condensing, and pelletizing units respectively were 10.24 ± 2.35, 12.15 ± 3.46, and 14.91 ± 4.16μ g d l . On the other hand, the average melatonin concentration values for administrative, condensing, and pelletizing units respectively were 37 ± 12.52, 34 ± 13.15, and 27 ± 9.54μ g d l . According to the results of the developed model for cortisol, SPL3 (32%) and age (5%) respectively had the highest and lowest impact. On the other hand, considering the model developed for melatonin, height (27%) and SPL1 (10%) were the most and least influential factors in that order. The accuracy rates of the model were also found to be 95% for cortisol and 97% for melatonin.

CONCLUSION

Comparing cortisol concentrations during various shifts revealed a significant reduction (from the beginning to the end of the shift) in all the three groups. Further, the rise of SPL would result in higher secretion of cortisol. Moreover, in all the three groups, the average serum melatonin concentration went up from the beginning to the middle of the shift and then declined to the end of the shift. Considering the accuracy rates of the models developed to predict hormones, neural network algorithm is a suitable and powerful tool for weighing and modelling factors influencing serum cortisol and melatonin concentrations.

Current Status and Future Directions of Chronic Cough in China

Chronic cough is one of the most common complaints for which patients in China seek medical attention. However, there are no nationwide data on the prevalence and socioeconomic burden of chronic cough. Although approximately 50% of Chinese men smoke, the vast majority of patients presenting for evaluation of chronic cough are never smokers. An equal sex distribution and a middle-aged predominance have been observed in the Chinese chronic cough population, despite demonstration of a higher cough reflex sensitivity in females and older patients. The role of air pollution in the distinct age and sex distribution requires further study. In terms of the etiologies of chronic cough in China, cough-variant asthma, upper airway cough syndrome, nonasthmatic eosinophilic bronchitis, and atopic cough are the most common causes, comprising 75.2% to 87.6% of cases across different regions. Chinese Guidelines for Diagnosis and Treatment of Cough were initially published in 2005, and updated in 2009 and 2016. In addition, the China Cough Coalition was established in 2016. Great progress has been made in both cough-related clinical practice and research in recent years, however, there are still challenges ahead. To facilitate optimal management of chronic cough in China, efforts promoting the dissemination and application of published guidelines will be essential, especially in community-based healthcare and in rural regions. As chronic refractory cough has been identified as a huge challenge to clinicians worldwide, continued international cooperation will be essential in optimizing evaluation and management of chronic cough.

Age and Sex Distribution of Chinese Chronic Cough Patients and Their Relationship With Capsaicin Cough Sensitivity

PURPOSE

An older female predominance has been reported among chronic cough patients in Western countries, which is considered to be associated with a higher cough sensitivity in females. However, the characteristics of Chinese chronic cough patients remain unclear. This study aimed to explore the age and sex distribution as well as their relationship with cough reflex sensitivity to capsaicin in Chinese chronic cough patients.

METHODS

We analyzed the demographic features of 1,882 consecutive chronic cough patients who attended our cough clinic in Guangzhou, China. Cough sensitivity to capsaicin, which was defined as the lowest concentration of capsaicin causing 5 coughs or more (C5), was measured in 539 of the 1,882 patients and 68 healthy volunteers.

RESULTS

The mean age of the patients was 43.0 ± 13.7 years and patients aged <50 years accounted for more than two-thirds of the study population. Around 87% of the patients were never-smokers. The proportion of females (51.5%) was almost equal to that of males (48.5%). The pattern of the age and sex distribution was consistently reflected within most common causes of chronic cough, while a female predominance was shown in patients with cough-variant asthma and patients aged ≥50 years. Female patients had higher cough sensitivity to capsaicin than male patients (log C5: 1.58 ± 0.84 vs. 2.04 ± 0.84 μmol/L, P = 0.001), and patients aged ≥50 years had higher cough sensitivity to capsaicin than patients aged <50 years.

CONCLUSIONS

In China, patients with chronic cough have a roughly equal sex distribution and a middle-aged predominance, irrespective of a higher cough sensitivity to capsaicin in females and older patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02591550.