Ambient and at-the-ear occupational noise exposure and serum lipid levels

Occupational noise and genetic variants in stress hormone biosynthesis-based genes and rates of blood lipid changes in China: A five-year longitudinal study

Lipid profiles are influenced by both noise and genetic variants. However, little is known about the associations of occupational noise and genetic variants with age-related changes in blood lipids, a crucial event in the initiation and evolution of atherosclerotic cardiovascular diseases. We aimed to evaluate the associations of blood lipid change rates with occupational noise and genetic variants in stress hormone biosynthesis-based genes. This cohort was established in 2012 and 2013 and was followed up until 2017. A total of 952 participants were included in the final analysis and all of them were categorized to two groups, the exposed group and control group, according to the exposed noise levels in their working area. Single nucleotide polymorphisms (SNPs) in stress hormone biosynthesis-based genes were genotyped. Five physical examinations were conducted from 2012 to 2017 and lipid measurements were repeated five times. The estimated annual changes (EACs) of blood lipid were calculated as the difference in blood lipid levels between any 2 adjacent examinations divided by their time interval (year). The generalized estimating equations for repeated measures analyses with exchangeable correlation structures were used to evaluate the influence of exposing to noise (versus being a control) and the SNPs mentioned above on the EACs of blood lipids. We found that the participants experienced accelerated age-related decline in high-density lipoprotein cholesterol (HDL-C) levels as they were exposed to noise (β = -0.38, 95% confidence interval (CI), -0.66 to -0.10, P = 0.007), after adjusting for work duration, gender, smoking, alcohol consumption, and pack-years. This trend was only found in participants with COMT-rs165815 TT genotype (β = -1.19, 95% CI, -1.80 to -0.58, P < 0.001), but not in those with the CC or CT genotypes. The interaction of noise exposure and rs165815 was marginally significant (Pinteraction = 0.010) after multiple adjustments. Compared with DDC-rs11978267 AA genotype carriers, participants carrying rs11978267 GG genotype had decreased EAC of triglycerides (TG) (β = -5.06, 95% CI, -9.07 to -1.05, P = 0.013). Participants carrying DBH-rs4740203 CC genotype had increased EAC of total cholesterol (TC) (β = 1.19, 95% CI, 0.06 to 2.33, P = 0.039). However, these findings were not statistically significant after multiple adjustments. These results indicated that Occupational noise exposure was associated with accelerated age-related decreases in HDL-C levels, and the COMT-rs165815 genotype appeared to modify the effect of noise exposure on HDL-C changes among the occupational population.

Association of noise exposure with lipid metabolism among Chinese adults: mediation role of obesity indices

PURPOSE

Noise exposure in the workplace has been linked to a number of health consequences. Our objectives were to explore the relationship between occupational noise and lipid metabolism and evaluate the possible mediating effect of obesity indices in those relationships with a cross-sectional study design.

METHODS

Cumulative noise exposure (CNE) was used to measure the level of noise exposure. Logistic regression models or generalized linear models were employed to evaluate the association of occupational noise and obesity with lipid metabolism markers. Cross-lagged analysis was conducted to explore temporal associations of obesity with lipid metabolism.

RESULTS

A total of 854 participants were included, with each one-unit increase in CNE, the values of total cholesterol/high-density lipoprotein cholesterol and low-density lipoprotein cholesterol/high-density lipoprotein cholesterol increased by 0.013 (95% confidence interval: 0.006, 0.020) and 0.009 (0.004, 0.014), as well as the prevalence of dyslipidemia increased by 1.030 (1.013, 1.048). Occupational noise and lipid metabolism markers were all positively associated with body mass index (BMI), waist circumference (WC), a Body Shape Index (ABSI) and a Body Shape Index and Body Roundness Index (BRI) (all P < 0.05). Moreover, BMI, WC, ABSI and BRI could mediate the associations of occupational noise with lipid metabolism; the proportions ranged from 21.51 to 24.45%, 23.84 to 30.14%, 4.86 to 5.94% and 25.59 to 28.23%, respectively (all P < 0.05).

CONCLUSIONS

Our study demonstrates a positive association between occupational noise and abnormal lipid metabolism, and obesity may partly mediate the association. Our findings reinforce the need to take practical steps to reduce or even eliminate the health risks associated with occupational noise.

Investigation of the Relationship Between Noise-Induced Hearing Loss and Metabolic Syndrome in One of the Oil Industries in the South of Iran

Investigating the non-auditory effects of noise on humans has been of interest from different aspects. In this study, the relationship between noise-induced hearing loss (NIHL) and metabolic syndrome. This cross-sectional study was performed on 1380 male workers of one of the oil and gas companies in the south of Iran. The data was obtained via clinical examination and hearing status assessment to evaluate the metabolic syndrome and its components, intravenous blood samples were taken and tested according to NCEPATPIII criteria. For statistical analysis, the data were analyzed using SPSS software version 25 at a significant level of 0.05. The results showed that the body mass index variable increased the chance of developing metabolic syndrome by 11.4%. NIHL increases the chance of developing metabolic syndrome (OR = 1.291). Also, the same results were observed in hypertriglyceridemia OR = 1.255, waist circumference (OR = 1.163), fasting blood sugar (OR = 1.159), blood pressure (OR = 1.068) and HDL (OR = 1.051). Considering the effect of NIHL on metabolic syndrome, it is possible to help reducing the incidence of metabolic syndrome and any of its components by controlling noise exposure and accordingly reducing non-auditory injuries to individuals.

Wearable Sensor-Based Monitoring of Environmental Exposures and the Associated Health Effects: A Review

Recent advances in sensor technology have facilitated the development and use of personalized sensors in monitoring environmental factors and the associated health effects. No studies have reviewed the research advancement in examining population-based health responses to environmental exposure via portable sensors/instruments. This study aims to review studies that use portable sensors to measure environmental factors and health responses while exploring the environmental effects on health. With a thorough literature review using two major English databases (Web of Science and PubMed), 24 eligible studies were included and analyzed out of 16,751 total records. The 24 studies include 5 on physical factors, 19 on chemical factors, and none on biological factors. The results show that particles were the most considered environmental factor among all of the physical, chemical, and biological factors, followed by total volatile organic compounds and carbon monoxide. Heart rate and heart rate variability were the most considered health indicators among all cardiopulmonary outcomes, followed by respiratory function. The studies mostly had a sample size of fewer than 100 participants and a study period of less than a week due to the challenges in accessing low-cost, small, and light wearable sensors. This review guides future sensor-based environmental health studies on project design and sensor selection.

Impact of Noise Exposure on Risk of Developing Stress-Related Metabolic Effects: A Systematic Review and Meta-Analysis

Background

Exposure to noise can increase biological stress reactions, which may increase adverse health effects, including metabolic disorders; however, the certainty in the association between exposure to noise and metabolic outcomes has not been widely explored. The objective of this review is to evaluate the evidence between noise exposures and metabolic effects.

Materials and Methods

A systematic review of English and comparative studies available in PubMed, Cochrane Central, EMBASE, and CINAHL databases between January 1, 1980 and December 29, 2021 was performed. Risk of Bias of Nonrandomized Studies of Exposures was used to assess risk of bias of individual studies and certainty of the body of evidence for each outcome was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Results

Fifty-six primary studies reporting on cortisol, cholesterol levels, waist circumference, glucose levels, and adrenaline and/or noradrenaline were identified. Although meta-analyses suggested that there may be an increase in waist circumference and adrenaline with increased noise exposure, the certainty in the evidence is very low. Overall, the certainty in the evidence of an effect of increased noise on all the outcomes were low to very low due to concerns with risk of bias, inconsistency across exposure sources, populations, and studies, and imprecision in the estimates of effects.

Conclusions

The certainty of the evidence of increased noise on metabolic effects was low to very low, which likely reflects the inability to compare across the totality of the evidence for each outcome. The findings from this review may be used to inform policies involving noise reduction and mitigation strategies, and to direct further research in areas that currently have limited evidence available.

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.

Traffic-related Noise Exposure and Late-life Dementia and Cognitive Impairment in Mexican-Americans

BACKGROUND

Recently, it has been suggested that environmental exposures from traffic sources including noise may play a role in cognitive impairment in the elderly. The objective of the study was to investigate the association between local traffic-related noise pollution and incident dementia or cognitive impairment without dementia (CIND) during a 10-year follow-up period.

METHODS

1612 Mexican-American participants from the Sacramento Area Latino Study on Aging (SALSA) were followed every 12-15 months via home visits from 1998 to 2007. We used the SoundPLAN software package to estimate noise originating from local traffic with the input of Annual Average Daily Traffic (AADT) data from Metropolitan Planning Organizations (MPO) based on geocoded residential addresses at baseline (1998-1999). We estimated the risks of incident dementia or CIND from 24-hour and nighttime noise exposure using Cox proportional hazard models.

RESULTS

During the follow-up, we identified 159 incident dementia or CIND cases in total. Per 11.6 dB (interquartile range width) increase in 24-hour noise, the hazard of developing dementia or CIND increased (hazard ratio = 1.3 [1.0, 1.6]) during follow-up; estimates were slightly lower (hazard ratio = 1.2 [0.97, 1.6]) when adjusting for modeled local air pollution exposure from traffic sources. Overall, the risk of dementia/CIND was elevated when 24-hour and nighttime noise were higher than 75 and 65 dB respectively. See video Abstract: http://links.lww.com/EDE/B728.

CONCLUSIONS

In our study, traffic-related noise exposure was associated with increased risk of dementia or CIND in elderly Mexican-Americans. Future studies taking into account other noise sources and occupational noise exposure before retirement are needed.

The Association between Noise Exposure and Metabolic Syndrome: A Longitudinal Cohort Study in Taiwan

Metabolic syndrome is becoming more common worldwide. Studies suggest environmental pollution, including traffic noise, might be linked with metabolic syndrome. This study sought to evaluate how noise exposure is linked to the development of metabolic syndrome and its components in Taiwan. Using data from a cohort of 42,509 participants and Cox proportional hazards regression models, the effects of noise exposure on metabolic syndrome and its components were quantified. After adjustment for covariates (age, gender, body mass index, and physical activity), the hazard ratio for metabolic syndrome was 1.13 (95% CI: 1.04–1.22) for medium noise exposure and 1.24 (95% CI: 1.13–1.36) for high noise exposure. Noise exposure was also positively associated with all of metabolic syndrome’s components. This finding suggests noise exposure might contribute to metabolic syndrome and its components. Policies aiming to reduce noise pollution might reduce the risks of metabolic syndrome and its components.

A Quantitative General Population Job Exposure Matrix for Occupational Noise Exposure

Occupational noise exposure is a known risk factor for hearing loss and also adverse cardiovascular effects have been suggested. A job exposure matrix (JEM) would enable studies of noise and health on a large scale. The objective of this study was to create a quantitative JEM for occupational noise exposure assessment of the general working population. Between 2001–2003 and 2009–2010, we recruited workers from companies within the 10 industries with the highest reporting of noise-induced hearing loss according to the Danish Working Environment Authority and in addition workers of financial services and children day care to optimize the range in exposure levels. We obtained 1343 personal occupational noise dosimeter measurements among 1140 workers representing 100 different jobs according to the Danish version of the International Standard Classification of Occupations 1988 (DISCO 88). Four experts used 35 of these jobs as benchmarks and rated noise levels for the remaining 337 jobs within DISCO 88. To estimate noise levels for all 372 jobs, we included expert ratings together with sex, age, occupational class, and calendar year as fixed effects, while job and worker were included as random effects in a linear mixed regression model. The fixed effects explained 40% of the total variance: 72% of the between-jobs variance, −6% of the between-workers variance and 4% of the within-worker variance. Modelled noise levels showed a monotonic increase with increasing expert score and a 20 dB difference between the highest and lowest exposed jobs. Based on the JEM estimates, metal wheel-grinders were among the highest and finance and sales professionals among the lowest exposed. This JEM of occupational noise exposure can be used to prioritize preventive efforts of occupational noise exposure and to provide quantitative estimates of contemporary exposure levels in epidemiological studies of health effects potentially associated with noise exposure.

Air pollution, noise exposure, and metabolic syndrome - A cohort study in elderly Mexican-Americans in Sacramento area

BACKGROUND

Previous studies suggested that air pollutants may increase the incidence of metabolic syndrome, but the potential impact from traffic sources is not well-understood. This study aimed to investigate associations between traffic-related nitrogen oxides (NOx) or noise pollution and risk of incident metabolic syndrome and its components in an elderly Mexican-American population.

METHODS

A total of 1,554 Mexican-American participants of the Sacramento Area Latino Study on Aging (SALSA) cohort were followed from 1998 to 2007. We used anthropometric measures and biomarkers to define metabolic syndrome according to the recommendations of the Third Adult Treatment Panel of the National Cholesterol Education Program (NCEP ATP III). Based on participants' residential addresses at baseline, estimates of local traffic-related NOx were generated using the California Line Source Dispersion Model version 4 (CALINE4), and of noise employing the SoundPLAN software package. We used Cox regression models with calendar time as the underlying time scale to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of air pollution or noise with metabolic syndrome or its components.

RESULTS

Each per unit increase of traffic-related NOx (2.29 parts per billion (ppb)) was associated with a 15% (HR = 1.15, 95% CI: 1.04-1.28) lower level of high-density lipoprotein cholesterol (HDL-cholesterol), and each 11.6 decibels (dB) increase in noise increased the risk of developing metabolic syndrome by 17% (HR = 1.17, 95% CI: 1.01-1.35).

CONCLUSION

Policies aiming to reduce traffic-related air pollution and noise might mitigate the risk of metabolic syndrome and its components in vulnerable populations.

Occupational noise exposure: A review of its effects, epidemiology, and impact with recommendations for reducing its burden

Exposure to hazardous noise is one of the most common occupational risks, both in the U.S. and worldwide. Repeated overexposure to noise at or above 85 dBA can cause permanent hearing loss, tinnitus, and difficulty understanding speech in noise. It is also associated with cardiovascular disease, depression, balance problems, and lower income. About 22 million U.S. workers are currently exposed to hazardous occupational noise. Approximately 33% of working-age adults with a history of occupational noise exposure have audiometric evidence of noise-induced hearing damage, and 16% of noise-exposed workers have material hearing impairment. While the Mining, Construction, and Manufacturing sectors typically have the highest prevalence of noise exposure and hearing loss, there are noise-exposed workers in every sector and every sector has workers with hearing loss. Noise-induced hearing loss is preventable. Increased understanding of the biological processes underlying noise damage may lead to protective pharmacologic or genetic therapies. For now, an integrated public health approach that (1) emphasizes noise control over reliance on hearing protection, (2) illustrates the full impact of hearing loss on quality of life, and (3) challenges the cultural acceptance of loud noise can substantially reduce the impact of noise on worker health.

Cardiovascular conditions, hearing difficulty, and occupational noise exposure within US industries and occupations

BACKGROUND

The purpose of this study was to estimate the prevalence of occupational noise exposure, hearing difficulty and cardiovascular conditions within US industries and occupations, and to examine any associations of these outcomes with occupational noise exposure.

METHODS

National Health Interview Survey data from 2014 were examined. Weighted prevalence and adjusted prevalence ratios of self-reported hearing difficulty, hypertension, elevated cholesterol, and coronary heart disease or stroke were estimated by level of occupational noise exposure, industry, and occupation.

RESULTS

Twenty-five percent of current workers had a history of occupational noise exposure (14% exposed in the last year), 12% had hearing difficulty, 24% had hypertension, 28% had elevated cholesterol; 58%, 14%, and 9% of these cases can be attributed to occupational noise exposure, respectively.

CONCLUSIONS

Hypertension, elevated cholesterol, and hearing difficulty are more prevalent among noise-exposed workers. Reducing workplace noise levels is critical. Workplace-based health and wellness programs should also be considered.

Long-term exposure to road traffic noise, ambient air pollution, and cardiovascular risk factors in the HUNT and lifelines cohorts

Aims

Blood biochemistry may provide information on associations between road traffic noise, air pollution, and cardiovascular disease risk. We evaluated this in two large European cohorts (HUNT3, Lifelines).

Methods and results

Road traffic noise exposure was modelled for 2009 using a simplified version of the Common Noise Assessment Methods in Europe (CNOSSOS-EU). Annual ambient air pollution (PM10, NO2) at residence was estimated for 2007 using a Land Use Regression model. The statistical platform DataSHIELD was used to pool data from 144 082 participants aged ≥20 years to enable individual-level analysis. Generalized linear models were fitted to assess cross-sectional associations between pollutants and high-sensitivity C-reactive protein (hsCRP), blood lipids and for (Lifelines only) fasting blood glucose, for samples taken during recruitment in 2006-2013. Pooling both cohorts, an inter-quartile range (IQR) higher day-time noise (5.1 dB(A)) was associated with 1.1% [95% confidence interval (95% CI: 0.02-2.2%)] higher hsCRP, 0.7% (95% CI: 0.3-1.1%) higher triglycerides, and 0.5% (95% CI: 0.3-0.7%) higher high-density lipoprotein (HDL); only the association with HDL was robust to adjustment for air pollution. An IQR higher PM10 (2.0 µg/m3) or NO2 (7.4 µg/m3) was associated with higher triglycerides (1.9%, 95% CI: 1.5-2.4% and 2.2%, 95% CI: 1.6-2.7%), independent of adjustment for noise. Additionally for NO2, a significant association with hsCRP (1.9%, 95% CI: 0.5-3.3%) was seen. In Lifelines, an IQR higher noise (4.2 dB(A)) and PM10 (2.4 µg/m3) was associated with 0.2% (95% CI: 0.1-0.3%) and 0.6% (95% CI: 0.4-0.7%) higher fasting glucose respectively, with both remaining robust to adjustment for air/noise pollution.

Conclusion

Long-term exposures to road traffic noise and ambient air pollution were associated with blood biochemistry, providing a possible link between road traffic noise/air pollution and cardio-metabolic disease risk.