A Cross-Sectional Study of Occupational Noise Exposure and Hypertension in Malaysia.

Introduction Noise is an occupational hazard that has been linked to negative effects beyond the auditory system, including hypertension. This study investigated the associations between occupational noise exposure and the risk of hypertension. Methods This cross-sectional study was conducted among state government employees. Data were collected through an online, self-administered questionnaire. Participants were divided into noise-exposed and non-noise-exposed groups based on their self-reported speech communication effort. Hypertension status was also self-reported. Descriptive analysis was performed on sociodemographic, lifestyle, medical history, and occupational characteristics to determine frequency and prevalence. Multiple logistic regression was conducted to compute the odds ratio (OR) and 95% confidence interval (CI) while adjusting for potential confounders. Results A total of 1005 state government employees were analyzed. The prevalence of hypertension was 18.8% among noise-exposed employees. After adjusting for age, sex, diabetes, dyslipidemia, BMI, and family history of hypertension, diabetes, and dyslipidemia, noise-exposed employees had a higher risk of hypertension, with an OR of 1.70 (95% CI = 1.09-2.66, p = 0.020), compared to non-exposed employees. Noise-exposed employees who had been exposed to occupational noise hazards for more than 10 years had a higher risk of hypertension (OR 2.04, 95% CI = 1.26-3.29, p = 0.004) compared to those who were unexposed. Conclusion Occupational noise exposure was associated with an increased risk of hypertension. These findings underscore the need to address noise exposure in the workplace and implement appropriate strategies to reduce its potential negative impact on employees' health.

Assessment of Real-Time Active Noise Control Devices in Dental Treatment Conditions.

Dental clinics are exposed to various uncomfortable noises. The aim of this study was to quantify the effectiveness of active noise control devices in dental treatment conditions. Two types of commercial headsets (Airpods Pro, QC30) and two types of dental headsets (Alltalk, Quieton Dental) were used for the experiment. Three sounds (high-speed handpiece, low-speed handpiece, and suction system) were measured at three different distances from the dental teeth model, typodont. The distances of 10, 40, and 70 cm reflected the positions of the patient, assistant, and practitioner's ears, respectively. Sound analysis was performed, and the significance of differences in the maximum noise level using each device was determined with the Kruskal−Wallis test. Dental noise was characterized by the peak in sound pressure level (SPL) at 4−5 kHz and >15 kHz frequencies. The commercial headsets efficiently blocked 1 kHz and 10 kHz of noise. The dental headsets efficiently reduced 4−6 and >15 kHz noise. Quieton had the highest maximum SPL in all situations and positions among the four devices. For a better dental clinic, however, active noise control devices more suitable for the characteristics of dental noise should be developed.

Noise Mapping, Prevalence and Risk Factors of Noise-Induced Hearing Loss among Workers at Muscat International Airport.

Noise-induced hearing loss (NIHL) is a common occupational hazard and a major cause of deafness among airport workers. However, few studies have been conducted to investigate the various risk factors related to hearing loss. PURPOSE: the purpose of this study was to measure the prevalence and risk factors of NIHL among Muscat International Airport airside workers. METHOD: Their daily noise exposure level at the airport was measured, and the time-weighted average (TWA) was calculated for each airside department. A cross-sectional study design involving 312 workers from the eight departments of the airport was chosen and the prevalence of NIHL among workers was assessed. The study participants then completed a self-administered questionnaire that covered their socio-demographic characteristics, occupational exposure history and the health-related risk factors of NIHL. RESULTS: The TWA recorded for the workers was above the accepted limit in some departments, namely, cabin appearance, ramp, line maintenance and hangar. The prevalence of NIHL among participants was 21.79% (n = 68). Of these 68 participants with NIHL, 22.30% were exposed to job-related high noise levels. NIHL was common among participants aged 40 or above (57.35%, n = 39) and high school degree holders (29.60%, n = 29), as well as those who were exposed to higher noise levels (84.89%, n = 191) or who did not wear their hearing protection devices (HPDs) regularly (53.65%, n = 125). CONCLUSION: around a quarter of our study participants who were exposed to high noise levels suffer from NIHL.

Analysis of noise hazard characteristics in automobile sand casting industry / 公共卫生与预防医学

Objective To study the characteristics of noise hazards in automobile sand casting industry and understand the impact of noise on the health of automobile foundry workers, and to provide scientific data support for the control of noise hazards. Methods An automobile sand casting enterprise was selected as the research object. The post noise intensity test results from 2010 to 2019, the noise spectrum test results of each post in 2019, and the prevalence of occupational noise deafness in the 10 years from 2010 to 2019 were analyzed and sorted out. Using chi-square test and t-test the noise hazard characteristics and noise intensity changes were statistically analyzed. Results 1. The noise LEX.8h exceeding standard rate of foundry enterprises in the 10 years from 2010 to 2019 was not statistically significant（χ2=6.76, P=0.66), and the mean value of noise LEX.8h fluctuated horizontally in the 10 years, which was basically stable between 80 - 90 dB (A). 2. The mean value of noise intensity of sand falling, sand preparation, cleaning and shot blasting in the first five years was significantly different compared to that in the last five years. There was no statistically significant difference in other posts. 3. Among all posts in the foundry sand casting industry, the noise spectrum of core-making and cleaning posts was mainly medium and high frequency, while the noise spectrum of other posts was mainly medium and low frequency. 4, Cases of occupational noise deafness were mainly concentrated in cleaning and polishing workers, melting chemical workers, inspectors and other types of workers. Conclusions The noise hazards in the automobile foundry sand casting industry are mainly concentrated on the posts of molding, and sand falling, and the noise intensity and the over standard rate remain high in the past 10 years. The noise of each post is mainly medium and low frequency, and the noise of a few individual posts is mainly medium and high frequency. In recent years, due to the automatic renewal of equipment, the noise intensity of some posts such as sand dropping, sand mixing, cleaning and shot blasting has decreased, but the overall noise exceeding standard rate has basically not changed, and the noise hazard is still serious. The noise hazard of foundry sand casting enterprises is difficult to be controlled, and the risk of hearing loss of foundry workers is still high.