Evaluating combined effect of noise and heat on blood pressure changes among males in climatic chamber

Occupational Noise-Induced Pre-Hypertension and Determinant Factors Among Metal Manufacturing Workers in Gondar City Administration, Northwest Ethiopia

Introduction

Cardiovascular disorders are one of the commonly recognized occupational diseases in the developed world. Individuals chronically exposed to noise at workplaces had a higher risk of developing elevated arterial blood pressure. There are limited studies in Ethiopia regarding this topic and thus this study determined the prevalence and determinant factors of occupational noise-induced pre-hypertension among metal manufacturing workers in Gondar city administration, Northwest Ethiopia.

Methods

An institution-based cross-sectional study design was carried out. In this study, 300 study participants were recruited by census sampling method. A sound level meter was used to measure the working area noise level. A semi-structured pre-tested interviewer-administered questionnaire was used to collect sociodemographic and clinical data. Blood pressure was measured in a quiet room in the morning using a mercurial sphygmomanometer. Both bivariable and multi-variable binary logistic regressions were used to identify factors associated with noise-induced prehypertension. Adjusted odds ratio with 95% confidence interval was reported, and variables with p < 0.05 were considered as statistically associated factors with pre-hypertension.

Results

The prevalence of noise-induced pre-hypertension was 27.7% (95% CI: 22.7-32.7). In multivariable logistic regression, working area noise level (AOR = 3.8, 95% CI: 6.8-8.9), 45-65 years' age (AOR = 9.8, 95% CI: 5.4-12.9), years of work experience ((6-10 years (AOR = 2.8, 95% CI: 1.98-5.90 and >10 years (AOR = 4.8, 95% CI: 7.8-9.75)), being a cigarette smoker (AOR = 3.6, 95% CI: 1.36-9.77), and alcohol consumption (AOR = 2.4, 95% CI: 1.06-1.04) were significantly associated with noise-induced prehypertension.

Conclusion

Workers in metal manufactures who were exposed to noise levels >85 dB developed elevated blood pressure. The odds of having prehypertension were increased by years of work experience, advanced age, smoking, and alcohol consumption. Our findings recommended that the real-world preventive strategies should be taken to lower the risk of noise-induced pre-hypertension hastened by occupational noise exposure.

Associations of Occupational Heat Stress and Noise Exposure with Carotid Atherosclerosis among Chinese Steelworkers: A Cross-Sectional Survey

Occupational exposure to heat stress and noise at the workplace are widespread physical hazards and have been associated with an increase in both morbidity and mortality. This study aims to examine the association between occupational heat stress and noise exposure and carotid atherosclerosis in Chinese steelworkers. A total of 3471 subjects were included in this study. Carotid plaque was measured using ultrasonography. The occupational information was collected by face-to-face personal interviews and all of the reported information was verified with the company's records. Workers were divided into non-exposure and exposure groups according to the company's records regarding previous and/or current heat stress and noise exposure status in the workplace. The prevalence of carotid plaque was 30.1% in the study population and workers exposed to both occupational heat stress and noise had the highest prevalence of carotid plaque at 37.2%. The odds of carotid plaque in individuals of different exposure status were significantly elevated after adjustment for potential confounders, especially in the heat stress and noise exposure combination group: OR = 1.32, 95% CI: 1.06 to 1.65, in individuals who had experienced heat stress exposure; OR = 1.49, 95% CI: 1.18 to 1.88, in individuals who had experienced noise exposure; OR = 2.02, 95% CI: 1.60 to 2.56, in the combination group. No significant association in female workers and no significant multiplicative or additive interactions were found between occupational heat stress and noise exposure and carotid plaque. Exposure to occupational heat stress and noise are statistically associated with carotid atherosclerosis among male steelworkers.

Can ultra short-term changes in ambient temperature trigger myocardial infarction?

BACKGROUND

Climate change is increasing global average temperatures, as well as the frequency of extreme weather events. Both low and high ambient temperatures have been associated with elevated mortality; however, little is known about the cardiovascular impacts of hourly temperature.

METHODS

We assessed the association between hourly ambient temperature and risk of myocardial infarction (MI) across adult residents of New York State (NYS). We identified cases across NYS hospitals from 2000 to 2015 in the New York Department of Health Statewide Planning and Research Cooperative System dataset, using ICD codes. Hourly ambient temperature was assessed at each patient's residential ZIP code, up to 48 hours prior to MI. We employed a time-stratified case-crossover study design matching case to control periods on hour of day, day of week, month and year.

RESULTS

Of the 791,695 primary MI hospital admissions, 45% were female, the mean (standard deviation; SD) age was 70 (15) years, and 49% of cases occurred among New York City residents. The observed temperature range was -29 °C to 39 °C, with a mean of 10.8 °C (10.5 °C). Temperature in the 6 h preceding the MI was positively associated with risk of MI, across the range of observed temperatures, with null or nearly null associations for earlier hours. We estimated a cumulative percent increase in hourly myocardial infarction rate of 7.9% (95% confidence interval [CI]: 5.2%, 10.6%) for an 11 °C (median) to 27 °C (95th percentile) temperature increase for lag hours 0-5. Men, Medicare-ineligible individuals (age < 65), and those experiencing their first MI were most sensitive.

CONCLUSION

Our study provides evidence that increases in hourly ambient temperature can trigger myocardial infarction. Health-based definitions of extreme heat events may better capture the deleterious effects of heat by accounting for hourly temperature. Our findings can inform the design of more effective preparedness strategies for the increasingly frequent extreme heat events.

The Influence of Occupational Noise Exposure on Cardiovascular and Hearing Conditions among Industrial Workers

This study was conducted to estimate the current prevalence of hypertension, cardiovascular condition and hearing difficulty of workers exposure to occupational noise, and to analyze any associations between these abnormal signs and occupational noise exposure. The subjects included 5205 noise-exposed workers. Workers with high noise exposure were more likely to have a higher threshold value than low exposure ones (P < 0.05). Subjects in the high exposure group had a significantly higher risk of hypertension and hearing loss than the ones in low exposure group. Between the ages of 30 and 45, high-level occupational noise exposure led to a significantly raising risk of both hypertension (Adjusted OR = 1.59, 95% CI, 1.19-2.11) and hearing loss (Adjusted OR = 1.28, 95% CI, 1.03-1.60) when comparing to low-level noise exposure. In male workers, the prevalence of hearing difficulty in high exposure group was approximately 1.2 times worse than in low group (P = 0.006). In addition, exposure to high noise level demonstrated a significant association with hypertension and hearing loss when the duration time to occupational noise was longer than 10 years. Hypertension and hearing difficulty is more prevalent in the noise-exposed group (higher than 85 dB[A]). Steps to reduce workplace noise levels and to improve workplace-based health are thus urgently needed.

The combined effects of occupational exposure to noise and other risk factors - a systematic review

PURPOSE

Noise-induced health effects exacerbate by many other risk factors. This systematic review aims at shedding light on the combined effects of co-exposure to occupational noise and other factors.

MATERIAL AND METHODS

A literature search in Web of Science, Scopus, PubMed, Science Direct, and Google Scholar, with appropriate keywords on combined effects of occupational noise, and co-exposure to noise and other factors, revealed 7928 articles which were screened by two researchers. A total of 775 articles were reviewed in full text. We found 149 articles that were relevant and had sufficient quality for analysis.

RESULTS

We identified 16 risk factors that exacerbate occupational noise-induced health effects. These factors were classified into four groups: chemical (carbon monoxide (CO), solvents, heavy metals, and other chemicals), physical (lighting, heat, vibration, and cold), personal (age, gender, genetics, smoking, medication, contextual diseases) and occupational (workload and shift work). Hearing loss, hypertension, reduced performance, and cardiovascular strains, are the most important risk factors combined effects due to concurrent exposure to noise and other risk factors.

CONCLUSION

Evidences of combined effects of solvents, vibration, heavy metals, CO, smoking, chemicals, aging, heat, and shiftwork were respectively stronger than for other factors. Most of the studies have investigated only the combined effects of risk factors on hearing, and the evidence for non-auditory effects is still limited, and more studies are warranted. Therefore, in the Hearing Conservation Programs, besides noise, aggravating factors of noise effects should also be taken into account.