Saliva cortisol and exposure to aircraft noise in six European countries

Long-term exposure to transportation noise and obesity: A pooled analysis of eleven Nordic cohorts

Background

Available evidence suggests a link between exposure to transportation noise and an increased risk of obesity. We aimed to assess exposure-response functions for long-term residential exposure to road traffic, railway and aircraft noise, and markers of obesity.

Methods

Our cross-sectional study is based on pooled data from 11 Nordic cohorts, including up to 162,639 individuals with either measured (69.2%) or self-reported obesity data. Residential exposure to transportation noise was estimated as a time-weighted average Lden 5 years before recruitment. Adjusted linear and logistic regression models were fitted to assess beta coefficients and odds ratios (OR) with 95% confidence intervals (CI) for body mass index, overweight, and obesity, as well as for waist circumference and central obesity. Furthermore, natural splines were fitted to assess the shape of the exposure-response functions.

Results

For road traffic noise, the OR for obesity was 1.06 (95% CI = 1.03, 1.08) and for central obesity 1.03 (95% CI = 1.01, 1.05) per 10 dB Lden. Thresholds were observed at around 50-55 and 55-60 dB Lden, respectively, above which there was an approximate 10% risk increase per 10 dB Lden increment for both outcomes. However, linear associations only occurred in participants with measured obesity markers and were strongly influenced by the largest cohort. Similar risk estimates as for road traffic noise were found for railway noise, with no clear thresholds. For aircraft noise, results were uncertain due to the low number of exposed participants.

Conclusion

Our results support an association between road traffic and railway noise and obesity.

Road traffic noise exposure and its impact on health: evidence from animal and human studies-chronic stress, inflammation, and oxidative stress as key components of the complex downstream pathway underlying noise-induced non-auditory health effects

In heavily urbanized world saturated with environmental pollutants, road traffic noise stands out as a significant factor contributing to widespread public health issues. It contributes in the development of a diverse range of non-communicable diseases, such as cardiovascular diseases, metabolic dysregulation, cognitive impairment, and neurodegenerative disorders. Although the exact mechanisms behind these non-auditory health effects remain unclear, the noise reaction model centres on the stress response to noise. When exposed to noise, the body activates the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, leading to the secretion of stress hormones like catecholamines and cortisol. Prolonged exposure to noise-induced stress results in chronic inflammation and oxidative stress. This review underscores the role of inflammation and oxidative stress in the progression of noise-induced vascular dysfunction, disruption of the circadian rhythm, accelerated aging, neuroinflammation, and changes in microbiome. Additionally, our focus is on understanding the interconnected nature of these health outcomes: These interconnected factors create a cascade effect, contributing to the accumulation of multiple risk factors that ultimately lead to severe adverse health effects.

Hair cortisol determinants in 11-year-old children: Environmental, social and individual factors

INTRODUCTION

Children's exposure to chronic stress is associated with several health problems. Measuring hair cortisol concentration is particularly useful for studying chronic stress but much is unknown about hair cortisol determinants in children and adolescents, and previous research has often not considered the simultaneous exposure of multiple variables. This research is focused on investigating the relationship between environmental, social and individual factors with hair cortisol concentration in children.

METHODS

The data used in this study are from the INMA prospective epidemiological cohort study. The assessment of chronic stress was made on the basis of hair samples taken at the age of 11 years in the INMA-Gipuzkoa cohort (n = 346). A metamodel summarizing the hypothesized relationships among environmental, social and individual factors and hair cortisol concentration was constructed based on previous literature. Structural Equation Modelling was performed to examine the relationships among the variables.

RESULTS

In the general model higher behavioural problems were associated with higher cortisol levels and an inverse relationship between environmental noise and cortisol levels was observed, explaining 5 % of the variance in HCC. Once stratified by sex these associations were only hold in boys, while no significant effect of any of the study variables was related with cortisol levels in girls. Importantly, maternal stress was positively related to behavioural difficulties in children. Finally, higher traffic-related air pollution and lower exposure to neighborhood greenness were related to higher environmental noise.

DISCUSSION

This study highlights that simultaneous exposure to different environmental, social and individual characteristics may determine the concentration of hair cortisol. More research is needed and future studies should include this complex view to better understanding of hair cortisol determinants in children.

Aircraft noise exposure and body mass index among female participants in two Nurses' Health Study prospective cohorts living around 90 airports in the United States

OBJECTIVE

Aircraft noise exposure is linked to cardiovascular disease risk. One understudied candidate pathway is obesity. This study investigates the association between aircraft noise and obesity among female participants in two prospective Nurses' Health Study (NHS and NHSII) cohorts.

METHODS

Aircraft day-night average sound levels (DNL) were estimated at participant residential addresses from modeled 1 dB (dB) noise contours above 44 dB for 90 United States (U.S.) airports in 5-year intervals 1995-2010. Biennial surveys (1994-2017) provided information on body mass index (BMI; dichotomized, categorical) and other individual characteristics. Change in BMI from age 18 (BMI18; tertiles) was also calculated. Aircraft noise exposures were dichotomized (45, 55 dB), categorized (<45, 45-54, ≥55 dB) or continuous for exposure ≥45 dB. Multivariable multinomial logistic regression using generalized estimating equations were adjusted for individual characteristics and neighborhood socioeconomic status, greenness, population density, and environmental noise. Effect modification was assessed by U.S. Census region, climate boundary, airline hub type, hearing loss, and smoking status.

RESULTS

At baseline, the 74,848 female participants averaged 50.1 years old, with 83.0%, 14.8%, and 2.2% exposed to <45, 45-54, and ≥55 dB of aircraft noise, respectively. In fully adjusted models, exposure ≥55 dB was associated with 11% higher odds (95% confidence interval [95%CI]: -1%, 24%) of BMIs ≥30.0, and 15% higher odds (95%CI: 3%, 29%) of membership in the highest tertile of BMI18 (ΔBMI 6.7 to 71.6). Less-pronounced associations were observed for the 2nd tertile of BMI18 (ΔBMI 2.9 to 6.6) and BMI 25.0-29.9 as well as exposures ≥45 versus <45 dB. There was evidence of DNL-BMI trends (ptrends ≤ 0.02). Stronger associations were observed among participants living in the West, arid climate areas, and among former smokers.

DISCUSSION

In two nationwide cohorts of female nurses, higher aircraft noise exposure was associated with higher BMI, adding evidence to an aircraft noise-obesity-disease pathway.

Transportation Noise Pollution and Cardiovascular Health

Epidemiological studies have found that transportation noise increases the risk for cardiovascular morbidity and mortality, with solid evidence for ischemic heart disease, heart failure, and stroke. According to the World Health Organization, at least 1.6 million healthy life years are lost annually from traffic-related noise in Western Europe. Traffic noise at night causes fragmentation and shortening of sleep, elevation of stress hormone levels, and increased oxidative stress in the vasculature and the brain. These factors can promote vascular (endothelial) dysfunction, inflammation, and arterial hypertension, thus elevating cardiovascular risk. The present review focusses on the indirect, nonauditory cardiovascular health effects of noise. We provide an updated overview of epidemiological research on the effects of transportation noise on cardiovascular risk factors and disease, and mechanistic insights based on the latest clinical and experimental studies and propose new risk markers to address noise-induced cardiovascular effects in the general population. We will discuss the potential effects of noise on vascular dysfunction, oxidative stress, and inflammation in humans and animals. We will elaborately explain the underlying pathomechanisms by alterations of gene networks, epigenetic pathways, circadian rhythm, signal transduction along the neuronal-cardiovascular axis, and metabolism. We will describe current and future noise mitigation strategies. Finally, we will conduct an overall evaluation of the status of the current evidence of noise as a significant cardiovascular risk factor.

Health position paper and redox perspectives - Disease burden by transportation noise

Transportation noise is a ubiquitous urban exposure. In 2018, the World Health Organization concluded that chronic exposure to road traffic noise is a risk factor for ischemic heart disease. In contrast, they concluded that the quality of evidence for a link to other diseases was very low to moderate. Since then, several studies on the impact of noise on various diseases have been published. Also, studies investigating the mechanistic pathways underlying noise-induced health effects are emerging. We review the current evidence regarding effects of noise on health and the related disease-mechanisms. Several high-quality cohort studies consistently found road traffic noise to be associated with a higher risk of ischemic heart disease, heart failure, diabetes, and all-cause mortality. Furthermore, recent studies have indicated that road traffic and railway noise may increase the risk of diseases not commonly investigated in an environmental noise context, including breast cancer, dementia, and tinnitus. The harmful effects of noise are related to activation of a physiological stress response and nighttime sleep disturbance. Oxidative stress and inflammation downstream of stress hormone signaling and dysregulated circadian rhythms are identified as major disease-relevant pathomechanistic drivers. We discuss the role of reactive oxygen species and present results from antioxidant interventions. Lastly, we provide an overview of oxidative stress markers and adverse redox processes reported for noise-exposed animals and humans. This position paper summarizes all available epidemiological, clinical, and preclinical evidence of transportation noise as an important environmental risk factor for public health and discusses its implications on the population level.

Exposure to low-intensity noise exacerbates nonalcoholic fatty liver disease by activating hypothalamus pituitary adrenal axis

Noise exposure induces metabolic disorders, in a latent, chronic and complex way. However, there is no direct evidence elucidating the relationship between low-intensity noise exposure and nonalcoholic fatty liver disease (NAFLD). Male mice (n = 5) on high-fat diet (HFD) were exposed to an average of 75 dB SPL noise for 3 months to reveal the effect of noise exposure on NAFLD, where the potential mechanisms were explored. In vivo (n = 5) and in vitro models challenged with dexamethasone (DEX) were used to verify the role of hypothalamus pituitary adrenal (HPA) axis activation in hepatic lipid metabolism. Typical chronic-restraint stress (CRS, n = 8) was used to explore the role of depression in modifying activity of HPA axis. Finally, animal experiment (n = 8) was repeated to validate the roles of depression and HPA axis activation in NAFLD development. Chronic low-intensity noise exposure exacerbated NAFLD in mice on HFD characterized by hepatocyte steatosis, modified lipid metabolism and inflammation level. Plasma ACTH in H + N group was 1.5-fold higher than that in HFD group. Transcription of glucocorticoid receptor target genes was increased by chronic low-intensity noise exposure in HFD-treated mice. Excessive glucocorticoids mimicking HPA axis activation induced NAFLD in vivo and in vitro. Plasma ACTH increase and lipid storage also occurred in depressive mice stressed by CRS. More interestingly, the same noise exposure simultaneously induced depression in mice, disrupted the HPA axis homeostasis and exacerbated NAFLD in a repeated experiment. Thus, three-month exposure to 75 dB SPL noise was sufficient to exacerbate NAFLD progress in mice, where activation of HPA axis played a critical role. Depression played an intermediate role and contributed to HPA axis activation up-stream of the exacerbation.

Salivary cortisone as potential predictor of occupational exposure to noise and related stress

Salivary cortisone strongly correlates with serum cortisol, and since it is less invasive to measure salivary cortisone than serum cortisol and easier than to measure cortisol in saliva, as its concentrations are much lower, we wanted to compare salivary cortisone and cortisol levels as markers of noise-induced stress reaction. The study included 104 participants aged 19-30 years, 50 of whom were exposed to occupational noise ≥85 dB(A) and 54 non-exposed, control students. All participants took samples of their saliva with Salivette® Cortisol synthetic swabs on three consecutive working days first thing in the morning. Salivary cortisone and cortisol levels were determined with high-performance liquid chromatography. In addition, they completed a 10-item Perceived Stress Scale (PSS-10) questionnaire, and occupationally noise-exposed participants also completed the Health and Safety Executive (HSE) questionnaire on occupational psychosocial risks. The exposed participants had significantly higher cortisone (P<0.001) and cortisol (P<0.001) levels than controls, and the correlation between cortisone and cortisol levels in the exposed participants was strong (ϱ =0.692, P<0.001), which suggests that salivary cortisone can replace cortisol measurements in saliva as a more reliable method than salivary cortisol and less invasive than serum cortisol. However, the level of perceived stress scored on PSS-10 in the exposed participants did not differ significantly from stress reported by controls, but correlated negatively with cortisone levels, which is contrary to our expectations and raises questions as to why.

Noise exposure and the risk of cancer: a comprehensive systematic review

The association between noise exposure and increased risk of cancer has received little attention in the field of research. Therefore, the goal of this study was to conduct a systematic review on the relationship between noise exposure and the incidence of cancer in humans. In this study, four electronic bibliographic databases including Scopus, PubMed, Web of Science, and Embase were systematically searched up to 21 April 2022. All types of noise exposure were considered, including environmental noise, occupational noise, and leisure or recreational noise. Furthermore, all types of cancers were studied, regardless of the organs involved. In total, 1836 articles were excluded on the basis of containing exclusion criteria or lacking inclusion criteria, leaving 19 articles retained for this study. Five of nine case-control studies showed a significant relationship between occupational or leisure noise exposure and acoustic neuroma. Moreover, four of five case-control and cohort studies indicated statistically significant relationships between environmental noise exposure and breast cancer. Of other cancer types, two case-control studies highlighted the risk of Hodgkin and non-Hodgkin lymphoma and two cohort studies identified an increased risk of colon cancer associated with environmental noise exposure. No relationship between road traffic and railway noise and the risk of prostate cancer was observed. In total, results showed that noise exposure, particularly prolonged and continuous exposure to loud noise, can lead to the incidence of some cancers. However, confirmation of this requires further epidemiological studies and exploration of the exact biological mechanism and pathway for these effects.

The relationship between exposure to environmental noise and risk of atopic dermatitis, asthma, and allergic rhinitis

BACKGROUND

Noise is defined as unwanted sound. It may induce negative emotions and mental health problems and may even lead to increased suicide risk. However, the impact of noise exposure on environmental diseases and disease severity is not well understood. This study aimed to elucidate the association between night-time noise exposure and the prevalence of environmental diseases in South Korea.

METHODS

We conducted an analysis of the Environmental Disease Database provide by the National Health Insurance Service (NHIS) from 2013 to 2017. After spatially interpolating the noise data provided by the National Noise Information System (NNIS), night-time noise values in the district level were obtained by calculating the mean noise values at the administrative district level. The linear regression analyses were performed to test the association between the age-standardized prevalence ratio (SPR) and the night-time noise exposure in the district level.

RESULTS

In areas with high night-time noise exposure (≥55 dB), the SPR for atopic dermatitis and allergic rhinitis were 1.0515 (95 % confidence interval [CI]:1.0508-1.0521) and 1.0202 (95 % CI:1.0201-1.0204), respectively, which were higher than those in the general population. The SPR for environmental diseases, including atopic dermatitis, asthma, and allergic rhinitis, was 1.0104 (95 % CI:1.0103-1.0105). Additionally, a significant linear association was observed between the level of nocturnal noise exposure and the total hospitalization period for atopic dermatitis (β = 399.3, p < 0.01).

CONCLUSION

We provide evidence of a significant association between night-time environmental noise and environmental diseases, particularly atopic dermatitis and allergic rhinitis. Furthermore, we observed a significant linear association between night-time noise exposure and the severity of atopic dermatitis.

The contribution of the exposome to the burden of cardiovascular disease

Large epidemiological and health impact assessment studies at the global scale, such as the Global Burden of Disease project, indicate that chronic non-communicable diseases, such as atherosclerosis and diabetes mellitus, caused almost two-thirds of the annual global deaths in 2020. By 2030, 77% of all deaths are expected to be caused by non-communicable diseases. Although this increase is mainly due to the ageing of the general population in Western societies, other reasons include the increasing effects of soil, water, air and noise pollution on health, together with the effects of other environmental risk factors such as climate change, unhealthy city designs (including lack of green spaces), unhealthy lifestyle habits and psychosocial stress. The exposome concept was established in 2005 as a new strategy to study the effect of the environment on health. The exposome describes the harmful biochemical and metabolic changes that occur in our body owing to the totality of different environmental exposures throughout the life course, which ultimately lead to adverse health effects and premature deaths. In this Review, we describe the exposome concept with a focus on environmental physical and chemical exposures and their effects on the burden of cardiovascular disease. We discuss selected exposome studies and highlight the relevance of the exposome concept for future health research as well as preventive medicine. We also discuss the challenges and limitations of exposome studies.

Long-term measurement study of urban environmental low frequency noise

BACKGROUND

Environmental low frequency noise (LFN < 125 Hz), ubiquitous in urban areas, is an understudied area of exposure science and an overlooked threat to population health. Environmental noise has historically been measured and regulated by A-weighted decibel (dBA) metrics, which more heavily weight frequencies between 2000 and 5000 Hz. Limited research has been conducted to measure and characterize the LFN components of urban environmental noise.

OBJECTIVES

We characterized LFN noise at two urban sites in Greater Boston, Massachusetts (USA) using dBA and full spectrum noise measurements with aims to (1.) analyze spatio-temporal differences in the two datasets; (2.) compare and contrast LFN metrics with dBA noise metrics in the two sites; and (3.) assess meteorological covariate contributions to LFN in the dataset.

METHODS

We measured A- and C-weighted, and flat, unweighted noise levels and 1/3-octave band continuously for 5 months using sound level meters sampling at f = 1 Hz and we recorded sound samples at 44.1 kHz. Our measurement sites were located in two urban, densely populated communities, burdened by close proximity to bus, rail, and aircraft routes.

RESULTS

We found that (1.) LFN does not follow the same seasonal trends as A-weighted dBA loudness; there are spatial differences in LFN and its very low frequency noise components (VLFN) between two urban sites; (2.) VLFN and LFN are statistically significant drivers of LCeq (nearly independent of frequency) minus LAeq, (LCeq-LAeq) >10 dB, an accepted LFN metric; and (3.) LFN was minimally affected by high wind speeds at either Site.

IMPACT STATEMENT

Environmental low-frequency noise (LFN < 125 Hz), ubiquitous in urban areas, is an understudied area of exposure science and an overlooked risk to population health. We measured environmental noise across the full spectrum of frequencies continuously for five months at two urban sites located in Environmental Justice communities. We found that LFN did not follow the same seasonal trends as A-weighted (dBA) loudness, and we observed spatial differences in LFN and very low frequency noise (VLFN < 20 Hz) at the two sites. Not characterizing LFN and basing noise regulations only on A-weightings, a poor predictor of LFN, may expose populations to LFN levels of concern.

Occupational and Environmental Noise Exposure and Extra-Auditory Effects on Humans: A Systematic Literature Review

Noise is a common harmful factor in our work and the environment. Most studies have investigated the auditory effects of noise exposure; however, few studies have focused on the extra-auditory effects of exposure to occupational or environmental noise. This study aimed to systematically review published studies on the extra-auditory effects of noise exposure. We reviewed literature from PubMed and Google Scholar databases up to July 2022, using the Patient, Intervention, Comparison, and Outcome criteria and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify studies that reported extra-auditory effects of occupational or environmental noise exposure. Studies were evaluated utilizing validated reporting tools (CONSORT, STROBE) appropriate to study design. A total of 263 articles were identified, of which 36 were finally selected and reviewed. Upon conducting a review of the articles, exposure to noise can elicit a variety of extra-auditory effects on humans. These effects include circulatory effects linked to higher risk of cardiovascular disease and decreased endothelial function, nervous system effects correlated with sleep disturbance, cognitive impairment, and mental health problems, immunological and endocrinal effects connected to increased physiological stress response and metabolic disorders, oncological and respiratory effects associated with an elevated risk of acoustic neuroma and respiratory disorders, gastrointestinal effects linked to an increased risk of gastric or duodenal ulcer, and obstetric effects connected to the risk of preterm birth. Our review suggests that there are numerous extra-auditory effects of noise exposure on human, and further investigations are needed to fully understand these effects.

Long-term exposure to traffic noise and risk of incident colon cancer: A pooled study of eleven Nordic cohorts

Background Colon cancer incidence is rising globally, and factors pertaining to urbanization have been proposed involved in this development. Traffic noise may increase colon cancer risk by causing sleep disturbance and stress, thereby inducing known colon cancer risk-factors, e.g. obesity, diabetes, physical inactivity, and alcohol consumption, but few studies have examined this. Objectives The objective of this study was to investigate the association between traffic noise and colon cancer (all, proximal, distal) in a pooled population of 11 Nordic cohorts, totaling 155,203 persons. Methods We identified residential address history and estimated road, railway, and aircraft noise, as well as air pollution, for all addresses, using similar exposure models across cohorts. Colon cancer cases were identified through national registries. We analyzed data using Cox Proportional Hazards Models, adjusting main models for harmonized sociodemographic and lifestyle data. Results During follow-up (median 18.8 years), 2757 colon cancer cases developed. We found a hazard ratio (HR) of 1.05 (95% confidence interval (CI): 0.99-1.10) per 10-dB higher 5-year mean time-weighted road traffic noise. In sub-type analyses, the association seemed confined to distal colon cancer: HR 1.06 (95% CI: 0.98-1.14). Railway and aircraft noise was not associated with colon cancer, albeit there was some indication in sub-type analyses that railway noise may also be associated with distal colon cancer. In interaction-analyses, the association between road traffic noise and colon cancer was strongest among obese persons and those with high NO₂-exposure. Discussion A prominent study strength is the large population with harmonized data across eleven cohorts, and the complete address-history during follow-up. However, each cohort estimated noise independently, and only at the most exposed façade, which may introduce exposure misclassification. Despite this, the results of this pooled study suggest that traffic noise may be a risk factor for colon cancer, especially of distal origin.

Air pollution and traffic noise interact to affect cognitive health in older Mexican Americans

BACKGROUND

Both air pollution and noise exposures have separately been shown to affect cognitive impairment. Here, we examine how air pollution and noise exposures interact to influence the development of incident dementia or cognitive impairment without dementia (CIND).

METHODS

We used 1,612 Mexican American participants from the Sacramento Area Latino Study on Aging conducted from 1998 to 2007. Air pollution (nitrogen dioxides, particulate matter, ozone) and noise exposure levels were modeled with a land-use regression and via the SoundPLAN software package implemented with the Traffic Noise Model applied to the greater Sacramento area, respectively. Using Cox proportional hazard models, we estimated the hazard of incident dementia or CIND from air pollution exposure at the residence up to 5-years prior to diagnosis for the members of each risk set at event time. Further, we investigated whether noise exposure modified the association between air pollution exposure and dementia or CIND.

RESULTS

In total, 104 incident dementia and 159 incident dementia/CIND cases were identified during the 10 years of follow-up. For each ∼2 µg/m3 increase in time-varying 1- and 5-year average PM2.5 exposure, the hazard of dementia increased 33% (HR = 1.33, 95%CI: 1.00, 1.76). The hazard ratios for NO2-related dementia/CIND and PM2.5-related dementia were stronger in high-noise (≥65 dB) exposed than low-noise (<65 dB) exposed participants.

CONCLUSION

Our study indicates that PM2.5 and NO2 air pollution adversely affect cognition in elderly Mexican Americans. Our findings also suggest that air pollutants may interact with traffic-related noise exposure to affect cognitive function in vulnerable populations.

Long-term aircraft noise exposure and risk of hypertension in postmenopausal women

BACKGROUND

Studies of the association between aircraft noise and hypertension are complicated by inadequate control for potential confounders and a lack of longitudinal assessments, and existing evidence is inconclusive.

OBJECTIVES

We evaluated the association between long-term aircraft noise exposure and risk of hypertension among post-menopausal women in the Women's Health Initiative Clinical Trials, an ongoing prospective U.S.

COHORT

METHODS

Day-night average (DNL) and night equivalent sound levels (Lnight) were modeled for 90 U.S. airports from 1995 to 2010 in 5-year intervals using the Aviation Environmental Design Tool and linked to participant geocoded addresses from 1993 to 2010. Participants with modeled exposures ≥45 A-weighted decibels (dB [A]) were considered exposed, and those outside of 45 dB(A) who also did not live in close proximity to unmodeled airports were considered unexposed. Hypertension was defined as systolic/diastolic blood pressure ≥140/90 mmHg or inventoried/self-reported antihypertensive medication use. Using time-varying Cox proportional hazards models, we estimated hazard ratios (HRs) for incident hypertension when exposed to DNL or Lnight ≥45 versus <45 dB(A), controlling for sociodemographic, behavioral, and environmental/contextual factors.

RESULTS/DISCUSSION

There were 18,783 participants with non-missing DNL exposure and 14,443 with non-missing Lnight exposure at risk of hypertension. In adjusted models, DNL and Lnight ≥45 db(A) were associated with HRs of 1.00 (95% confidence interval [CI]: 0.93, 1.08) and 1.06 (95%CI: 0.91, 1.24), respectively. There was no evidence supporting a positive exposure-response relationship, and findings were robust in sensitivity analyses. Indications of elevated risk were seen among certain subgroups, such as those living in areas with lower population density (HRinteraction: 0.84; 95%CI: 0.72, 0.98) or nitrogen dioxide concentrations (HRinteraction: 0.82; 95%CI: 0.71, 0.95), which may indicate lower ambient/road traffic noise. Our findings do not suggest a relationship between aircraft noise and incident hypertension among older women in the U.S., though associations in lower ambient noise settings merit further investigation.

Exposure to outdoor residential noise during pregnancy, embryonic size, fetal growth, and birth outcomes

INTRODUCTION

Previous literature suggested that noise exposure during pregnancy was not associated with adverse birth outcomes. However, no studies evaluated the association between noise exposure and embryonic and fetal growth, or mutually assessed other urban environmental exposures such as traffic-related air pollution or natural spaces.

METHODS

We included 7947 pregnant women from the Generation R Study, the Netherlands. We estimated total (road traffic, aircraft, railway, and industry), road traffic, and railway noise at the participants' home addresses during pregnancy using environmental noise maps. We estimated traffic-related air pollution using land-use regression models, greenness within a 300 m buffer using the normalized difference vegetation index, and distance to blue spaces using topographical maps at the home addresses. Embryonic size (crown-rump length) and fetal growth parameters (head circumference, femur length, and estimated fetal weight) were measured by ultrasound at several gestational ages. Information on neonatal anthropometrics at birth (head circumference, length, and weight) and adverse birth outcomes (preterm birth, low birth weight, and small for gestational age) were retrieved from medical records.

RESULTS

Higher total noise exposure during pregnancy was associated with larger crown-rump length (0.07 SDS [95%CI 0.00 to 0.14]). No association was found with fetal growth parameters, neonatal anthropometrics, and adverse birth outcomes. Similar results were observed for road traffic noise exposure, while railway noise exposure was not associated with any of the outcomes. Traffic-related air pollution was not associated with crown-rump length. Total noise exposure mediated 15% of the association between exposure to greenness and smaller crown-rump length. No association was observed between distance to blue spaces and total noise exposure.

CONCLUSION

Exposure to outdoor residential noise during pregnancy was associated with larger embryonic size. Moreover, a reduction of total noise exposure during pregnancy partially mediated the association between exposure to greenness and smaller embryonic size. Additional research is warranted to confirm and further understand these novel findings.

Co-exposure to urban particulate matter and aircraft noise adversely impacts the cerebro-pulmonary-cardiovascular axis in mice

Worldwide, up to 8.8 million excess deaths/year have been attributed to air pollution, mainly due to the exposure to fine particulate matter (PM). Traffic-related noise is an additional contributor to global mortality and morbidity. Both health risk factors substantially contribute to cardiovascular, metabolic and neuropsychiatric sequelae. Studies on the combined exposure are rare and urgently needed because of frequent co-occurrence of both risk factors in urban and industrial settings. To study the synergistic effects of PM and noise, we used an exposure system equipped with aerosol generator and loud-speakers, where C57BL/6 mice were acutely exposed for 3d to either ambient PM (NIST particles) and/or noise (aircraft landing and take-off events). The combination of both stressors caused endothelial dysfunction, increased blood pressure, oxidative stress and inflammation. An additive impairment of endothelial function was observed in isolated aortic rings and even more pronounced in cerebral and retinal arterioles. The increase in oxidative stress and inflammation markers together with RNA sequencing data indicate that noise particularly affects the brain and PM the lungs. The combination of both stressors has additive adverse effects on the cardiovascular system that are based on PM-induced systemic inflammation and noise-triggered stress hormone signaling. We demonstrate an additive upregulation of ACE-2 in the lung, suggesting that there may be an increased vulnerability to COVID-19 infection. The data warrant further mechanistic studies to characterize the propagation of primary target tissue damage (lung, brain) to remote organs such as aorta and heart by combined noise and PM exposure.

Acute Exposure to Simulated Nocturnal Train Noise Leads to Impaired Sleep Quality and Endothelial Dysfunction in Young Healthy Men and Women: A Sex-Specific Analysis

A series of human field studies demonstrated that simulated nocturnal traffic noise exposure impaired sleep quality and endothelial function, which could be significantly improved after intake of vitamin C in case of endothelial function. However, it remains unclear whether these changes follow a sex-specific pattern. Thus, we aimed to analyze the effect of simulated nocturnal train noise exposure on sleep quality, endothelial function and its associated changes after vitamin C intake, and other hemodynamic and biochemical parameters in young healthy men and women. We used data from a randomized crossover study, wherein 70 healthy volunteers (50% women) were each exposed to one control pattern (regular background noise) and two different train noise scenarios (30 or 60 train noise events per night, with average sound pressure levels of 52 and 54 dB(A), respectively, and peak sound level of 73-75 dB(A)) in their homes for three nights. After each night, participants visited the study center for the measurement of endothelial function as well as other hemodynamic and biochemical parameters. Sleep quality measured via self-report was significantly impaired after noise 30 and noise 60 nights in both men and women (p < 0.001 vs. control). Likewise, endothelial function measured by flow-mediated dilation (FMD) was significantly impaired after noise 30 and noise 60 nights in both men and women (p < 0.001 vs. control). While in women, vitamin C intake significantly improved FMD after both noise 30 and noise 60 study nights compared to control nights, no significant changes were observed in men. Exposure to simulated nocturnal train noise impairs sleep quality and endothelial function in both men and women, whereas a significant improvement of endothelial function after noise exposure and vitamin C intake could only be observed in women. These findings suggest for the first time that in men other mechanisms such as oxidative stress causing endothelial dysfunction may come into play.

Hair cortisol as a viable tool for the assessment of an association between environmental noise exposure and chronic stress

Entrenched in the well-established link between stress and health, noise exposure as a potential contributor to stress-related health effects receives tremendous attention. Indeed, exposure to noise can act as a stressor as evidenced through increased heart rate, blood pressure, adrenaline, epinephrine, and cortisol. Cortisol is secreted from the adrenal glands in response to stressor-induced activation of the hypothalamic-pituitary-adrenal axis. For assessment of environmental noise and stress, repeated sampling in blood, saliva, or urine is necessary to evaluate the association between environmental noise exposure and protracted changes in cortisol. Controlling for the many variables that influence the secretion of cortisol at discrete sampling intervals is challenging. Studies suggest that systemically produced cortisol integrates and remains in hair as it grows, providing a measure that integrates a cortisol response over a longer period, circumventing several limitations associated with multiple sampling. Robust evidence supports the integration of cortisol into hair, yet recent studies call into question the notion that cortisol is retained with growth. The current paper discusses the strengths and limitations of hair cortisol analysis with an emphasis on its utility as a measure of chronic stress in environmental noise studies.

Traffic noise and adiposity: a systematic review and meta-analysis of epidemiological studies

Traffic noise has attracted much attention as a significant and intractable public health threat. This study was designed as a systematical review to explore the association of traffic noise with different indicators of obesity, thus providing updated quantitative estimates for the pooled effect estimates of the existing literature. We conducted an extensive search for epidemiological studies that investigated the association of traffic noise with obesity in three electronic databases till February 23, 2021. We used random-effects meta-analysis to calculate the summary effect estimates for each 10-dB(A) increase in noise and compared the highest with the lowest category of noise in relation to seven obesity indicators. Meanwhile, we assessed the risk of bias and the overall quality of the evidence of each study as well as the level of evidence for each exposure-outcome pair. The initial search identified 30 studies, 13 of which were ultimately included. The meta-analysis for the highest versus the lowest category of noise exposure was generally associated with higher waist circumfluence (WC) ranging from 0.326 cm (95% confidence interval (CI) = 0.078, 0.574) to 0.705 cm (95% CI = 0.071, 1.340) and higher odds of central obesity ranging from 1.055 (95% CI = 1.000, 1.109) to 1.167 (95% CI = 1.037, 1.298). When the continuous exposure (each 10 dB(A) increase in noise) was introduced, similar results were found. This study indicated positive associations of traffic noise with WC and central obesity. However, in consideration of some limitations, there is an urgent need for future studies to increase the sample size, discriminate the etiological differences in different noise and obesity indicators, and thoroughly consider socioeconomic status.

Exposure to transportation noise and risk for cardiovascular disease in a nationwide cohort study from Denmark

BACKGROUND

Transportation noise increases the risk of ischemic heart disease (IHD), but few studies have investigated subtypes of IHD, such as myocardial infarction (MI), angina pectoris, or heart failure. We aimed to study whether exposure to road, railway and aircraft noise increased risk for ischemic heart disease (IHD), IHD subtypes, and heart failure in the entire adult Danish population, investigating exposures at both maximum exposed and silent façades of each residence.

METHODS

We modelled road, railway, and aircraft noise at the most and least exposed façades for the period 1995-2017 for all addresses in Denmark and calculated 10-year time-weighted running means for 2.5 million individuals age ≥50 years, of whom 122,523 developed IHD and 79,358 developed heart failure during follow-up (2005-2017). Data were analyzed using Cox proportional hazards models, adjusted for individual and area-level sociodemographic covariates and air pollution.

RESULTS

We found road traffic noise at the most exposed façade (L_den) to be associated with higher risk of IHD, myocardial infarction (MI), angina pectoris, and heart failure, with hazard ratios (HRs) (95% confidence intervals (CI)) of 1.052 (1.044-1.059), 1.041 (1.032-1.051), 1.095 (1.071-1.119), and 1.039 (1.033-1.045) per 10 dB higher 10-year mean exposure, respectively. These associations followed a near-linear exposure-response relationship and were robust to adjustment for air pollution with PM_2.5. Railway noise at the least exposed façade was associated with heart failure (HR 1.28; 95% CI: 1.004-1.053), but not the other outcomes. Exposure to aircraft noise (>45 dB) seemed associated with increased risk for MI and heart failure.

CONCLUSIONS

We found road traffic noise and potentially railway and aircraft noise to increase risk of various major cardiovascular outcomes, highlighting the importance of preventive actions towards transportation noise.

Long-term exposure to transportation noise and risk for atrial fibrillation: A Danish nationwide cohort study

BACKGROUND

Epidemiological studies have linked transportation noise and cardiovascular diseases, however, atrial fibrillation (AF) has received limited attention. We aimed to investigate the association between transportation noise and AF risk.

METHODS

Over the period 1990-2017 we estimated road and railway noise (L_den) at the most and least exposed façades for all residential addresses across Denmark. We estimated time-weighted mean noise exposure for 3.6 million individuals age ≥35 years. Of these, 269,756 incident cases of AF were identified with a mean follow-up of 13.0 years. Analyses were conducted using Cox proportional hazards models with adjustment for individual and area-level sociodemographic covariates and long-term residential air pollution.

RESULTS

A 10 dB higher 10-year mean road traffic noise at the most and least exposed façades were associated with incidence rate ratios (IRR) and 95% confidence intervals (CI) for AF of 1.006 (1.001-1.011) and 1.013 (1.007-1.019), respectively. After further adjustment for PM_2.5, the IRRs (CIs) were 1.000 (0.995-1.005) and 1.007 (1.000-1.013), respectively. For railway noise, the IRRs per 10 dB increase in 10-year mean exposure were 1.017 (1.007-1.026) and 1.035 (1.021-1.050) for the most and least exposed façades, respectively, and were slightly attenuated when adjusted for PM_2.5. Aircraft noise between 55 and 60 dB and ≥60 dB were associated with IRRs of 1.055 (0.996-1.116) and 1.036 (0.931-1.154), respectively, when compared to <45 dB.

CONCLUSION

Transportation noise seems to be associated with a small increase in AF risk, especially for exposure at the least exposed façade.

Long-Term Effects of Aircraft Noise Exposure on Vascular Oxidative Stress, Endothelial Function and Blood Pressure: No Evidence for Adaptation or Tolerance Development

Transportation noise is recognized as an important cardiovascular risk factor. Key mechanisms are noise-triggered vascular inflammation and oxidative stress with subsequent endothelial dysfunction. Here, we test for adaptation or tolerance mechanisms in mice in response to chronic noise exposure. C57BL/6J mice were exposed to aircraft noise for 0, 4, 7, 14 and 28d at a mean sound pressure level of 72 dB(A) and peak levels of 85 dB(A). Chronic aircraft noise exposure up to 28d caused persistent endothelial dysfunction and elevation of blood pressure. Likewise, reactive oxygen species (ROS) formation as determined by dihydroethidium (DHE) staining and HPLC-based measurement of superoxide formation in the aorta/heart/brain was time-dependently increased by noise. Oxidative burst in the whole blood showed a maximum at 4d or 7d of noise exposure. Increased superoxide formation in the brain was mirrored by a downregulation of neuronal nitric oxide synthase (Nos3) and transcription factor Foxo3 genes, whereas Vcam1 mRNA, a marker for inflammation was upregulated in all noise exposure groups. Induction of a pronounced hearing loss in the mice was excluded by auditory brainstem response audiometry. Endothelial dysfunction and inflammation were present during the entire 28d of aircraft noise exposure. ROS formation gradually increases with ongoing exposure without significant adaptation or tolerance in mice in response to chronic noise stress at moderate levels. These data further illustrate health side effects of long-term noise exposure and further strengthen a consequent implementation of the WHO noise guidelines in order to prevent the development of noise-related future cardiovascular disease.

Association between physical hazardous agent exposure and mental health in the Korean working population: the 5th Korean Working Conditions Survey

Background

Mental health problems are emerging issues in occupational safety and health, whereas the findings on the relationship between physical hazards and mental health are not consistent. The aim of our study was to investigate the association between physical hazard exposure and mental health outcomes including depression and anxiety.

Methods

We included 48,476 participants from the fifth Korean Working Conditions Survey (KWCS) in this study. The χ² test and logistic regression analyses were conducted to assess the association between physical hazard exposures and mental health. All statistical analyses were performed sex-specifically.

Results

In logistic regression analysis, the odds ratios (ORs) of depression were significantly increased in male workers who were exposed to vibration (severe OR: 1.54, 95% confidence interval [CI]: 1.21–1.95) and noise (severe OR: 1.93, 95% CI: 1.49–2.48) whereas the ORs of depression were not significant in female workers from vibration (severe OR: 0.86, 95% CI: 0.50–1.38) or noise exposure (severe OR: 1.39, 95% CI: 0.84–2.17). The ORs of anxiety were significantly increased in male workers with vibration (severe OR: 1.76, 95% CI: 1.43–2.15) and noise exposure (severe OR: 2.12, 95% CI: 1.69–2.63) whereas the OR between vibration and anxiety (severe OR: 1.45, 95% CI: 0.91–2.21) was not significant in female workers. High or low temperature exposure had significant associations with depression and anxiety in both male and female subjects.

Conclusions

Results of our study suggest that physical hazard exposures may be associated with increased risk of mental health problems including depression and anxiety. These associations are more prominent in male workers in comparison with female workers.

The causal effect of household chaos on stress and caregiving: An experimental study

The correlational nature of previous studies on household chaos does not allow claims about causal effects of household chaos. The present study used an experimental design to assess the causal effect of household chaos on stress, negative emotions, and caregiving. Ninety-six female students (18–25 years) participated in our study. They took care of an infant simulator in a normal living room (neutral condition), and a chaotic living room (chaos condition), while caregiver sensitivity was observed, operationalized as perceiving, correctly interpreting, and responding accurately and promptly to the infant's signals. Participants reported on their current emotional state, and saliva was collected four times for analysis of salivary alpha-amylase (sAA). Results showed that there were no significant time or condition effects on negative emotional state. Yet, sAA levels were higher in the chaos condition compared to the neutral condition. We found no evidence for negative emotional state or sAA mediating the relation between household chaos and caregiver sensitivity. Because household chaos affected physiological stress in a parenting situation, it should not be ignored when using interventions aimed at reducing stress in parents. More research is needed on the effect of reduced (as opposed to increased) levels of household chaos on physiological stress levels in families with young children.

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Household chaos is causally related to physiological stress in a caregiving context.

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Household chaos does not affect self-reported negative emotions.

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No evidence for stress mediating the relation between household chaos and caregiving.

Residential exposure to transportation noise in Denmark and incidence of dementia: national cohort study

OBJECTIVE

To investigate the association between long term residential exposure to road traffic and railway noise and risk of incident dementia.

DESIGN

Nationwide prospective register based cohort study.

SETTING

Denmark.

PARTICIPANTS

1 938 994 adults aged ≥60 years living in Denmark between 1 January 2004 and 31 December 2017.

MAIN OUTCOME MEASURES

Incident cases of all cause dementia and dementia subtypes (Alzheimer's disease, vascular dementia, and Parkinson's disease related dementia), identified from national hospital and prescription registries.

RESULTS

The study population included 103 500 participants with incident dementia, and of those, 31 219 received a diagnosis of Alzheimer's disease, 8664 of vascular dementia, and 2192 of Parkinson's disease related dementia. Using Cox regression models, 10 year mean exposure to road traffic and railway noise at the most (L_denmax) and least (L_denmin) exposed façades of buildings were associated with a higher risk of all cause dementia. These associations showed a general pattern of higher hazard ratios with higher noise exposure, but with a levelling off or even small declines in risk at higher noise levels. In subtype analyses, both road traffic noise and railway noise were associated with a higher risk of Alzheimer's disease, with hazard ratios of 1.16 (95% confidence interval 1.11 to 1.22) for road L_denmax ≥65 dB compared with <45 dB, 1.27 (1.22 to 1.34) for road L_denmin ≥55 dB compared with <40 dB, 1.16 (1.10 to 1.23) for railway L_denmax ≥60 dB compared with <40 dB, and 1.24 (1.17 to 1.30) for railway L_denmin ≥50 dB compared with <40 dB. Road traffic, but not railway, noise was associated with an increased risk of vascular dementia. Results indicated associations between road traffic L_denmin and Parkinson's disease related dementia.

CONCLUSIONS

This nationwide cohort study found transportation noise to be associated with a higher risk of all cause dementia and dementia subtypes, especially Alzheimer's disease.

Aircraft noise exposure drives the activation of white blood cells and induces microvascular dysfunction in mice

Epidemiological studies showed that traffic noise has a dose-dependent association with increased cardiovascular morbidity and mortality. Whether microvascular dysfunction contributes significantly to the cardiovascular health effects by noise exposure remains to be established. The connection of inflammation and immune cell interaction with microvascular damage and functional impairment is also not well characterized. Male C57BL/6J mice or gp91phox^−/y mice with genetic deletion of the phagocytic NADPH oxidase catalytic subunit (gp91phox or NOX-2) were used at the age of 8 weeks, randomly instrumented with dorsal skinfold chambers and exposed or not exposed to aircraft noise for 4 days. Proteomic analysis (using mass spectrometry) revealed a pro-inflammatory phenotype induced by noise exposure that was less pronounced in noise-exposed gp91phox^−/y mice. Using in vivo fluorescence microscopy, we found a higher number of adhesive leukocytes in noise-exposed wild type mice. Dorsal microvascular diameter (by trend), red blood cell velocity, and segmental blood flow were also decreased by noise exposure indicating microvascular constriction. All adverse effects on functional parameters were normalized or improved at least by trend in noise-exposed gp91phox^−/y mice. Noise exposure also induced endothelial dysfunction in cerebral microvessels, which was associated with higher oxidative stress burden and inflammation, as measured using video microscopy. We here establish a link between a pro-inflammatory phenotype of plasma, activation of circulating leukocytes and microvascular dysfunction in mice exposed to aircraft noise. The phagocytic NADPH oxidase was identified as a central player in the underlying pathophysiological mechanisms.

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Noise exposure induces a pro-thrombo-inflammatory phenotype in mouse plasma.

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Aircraft noise increases leukocyte-endothelium interactions in dorsal microvessels.

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Noise decreases segmental blood flow/red blood cell velocity in dorsal microvessels.

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Noise increases cerebral microvascular dysfunction and oxidative stress.

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Nox2 deficiency (gp91phox^-/y) improves noise-induced adverse effects.

Ablation of lysozyme M-positive cells prevents aircraft noise-induced vascular damage without improving cerebral side effects

Aircraft noise induces vascular and cerebral inflammation and oxidative stress causing hypertension and cardiovascular/cerebral dysfunction. With the present studies, we sought to determine the role of myeloid cells in the vascular vs. cerebral consequences of exposure to aircraft noise. Toxin-mediated ablation of lysozyme M+ (LysM+) myeloid cells was performed in LysMCreiDTR mice carrying a cre-inducible diphtheria toxin receptor. In the last 4d of toxin treatment, the animals were exposed to noise at maximum and mean sound pressure levels of 85 and 72 dB(A), respectively. Flow cytometry analysis revealed accumulation of CD45+, CD11b+, F4/80+, and Ly6G-Ly6C+ cells in the aortas of noise-exposed mice, which was prevented by LysM+ cell ablation in the periphery, whereas brain infiltrates were even exacerbated upon ablation. Aircraft noise-induced increases in blood pressure and endothelial dysfunction of the aorta and retinal/mesenteric arterioles were almost completely normalized by ablation. Correspondingly, reactive oxygen species in the aorta, heart, and retinal/mesenteric vessels were attenuated in ablated noise-exposed mice, while microglial activation and abundance in the brain was greatly increased. Expression of phagocytic NADPH oxidase (NOX-2) and vascular cell adhesion molecule-1 (VCAM-1) mRNA in the aorta was reduced, while NFκB signaling appeared to be activated in the brain upon ablation. In sum, we show dissociation of cerebral and peripheral inflammatory reactions in response to aircraft noise after LysM+ cell ablation, wherein peripheral myeloid inflammatory cells represent a dominant part of the pathomechanism for noise stress-induced cardiovascular effects and their central nervous counterparts, microglia, as key mediators in stress responses.

Non-auditory effects of industrial chronic noise exposure on workers; change in salivary cortisol pattern

Background

Noise has different auditory and non-auditory effects on human. In noisy environments, noise as a non-specific stressor can activates the hypothalamic-pituitary-adrenal axis (HPA, cortisol). The aim of this study was to evaluate the effect of chronic exposure to noise on salivary cortisol on industrial workers.

Methods

This cross-sectional study had a case/control design. 136 male workers (68 workers were exposed to chronic industrial noise, and 68 other workers were exposed to background noise) voluntarily enrolled in the study. The equivalent noise level was measured at workstations and salivary cortisol for both case and control groups was measured at the beginning (6 AM) and also at the end of work shift (4 PM). The amount of change in the average of the values of the two groups were compared with each other.

Results

The measured Leq_8h (equivalent continuous sound level) in case and control groups were 87.43 dB-A and 67.6 dB-A, respectively. Comparison of salivary cortisol levels change in groups shows a significant differences in control groups for salivary cortisol in the morning and in the evening samples (p < 0.05); but not in the case group (p = 0.052). Also, comparison of salivary cortisol levels changes with noise exposure experience in the case subgroups revealed no significant difference (p > 0.05).

Conclusion

This study showed that chronic exposure to industrial noise can lead to a change in pattern of salivary cortisol secretion especially in the evening (at the end of the work shift), in a way that instead of its normal decrease, an increase happened.

The role of aircraft noise annoyance and noise sensitivity in the association between aircraft noise levels and medication use: results of a pooled-analysis from seven European countries

BACKGROUND

Few studies have considered aircraft noise annoyance and noise sensitivity in analyses of the health effects of aircraft noise, especially in relation to medication use. This study aims to investigate the moderating and mediating role of these two factors in the relationship between aircraft noise levels and medication use among 5860 residents of ten European airports included in the HYENA and DEBATS studies.

METHODS

Information on aircraft noise annoyance, noise sensitivity, medication use, and demographic, socio-economic and lifestyle factors was collected during a face-to-face interview at home. Medication was coded according to the Anatomical Therapeutic Chemical (ATC) classification. Outdoor aircraft noise exposure was estimated by linking the participant's home address to noise contours using Geographical Information Systems (GIS) methods. Logistic regressions with adjustment for potential confounding factors were used. In addition, Baron and Kenny's recommendations were followed to investigate the moderating and mediating effects of aircraft noise annoyance and noise sensitivity.

RESULTS

A significant association was found between aircraft noise levels at night and antihypertensive medication only in the UK (OR = 1.43, 95%CI 1.19-1.73 for a 10 dB(A)-increase in L_night). No association was found with other medications. Aircraft noise annoyance was significantly associated with the use of antihypertensive medication (OR = 1.33, 95%CI 1.14-1.56), anxiolytics (OR = 1.48, 95%CI 1.08-2.05), hypnotics and sedatives (OR = 1.60, 95%CI 1.07-2.39), and antasthmatics (OR = 1.44, 95%CI 1.07-1.96), with no difference between countries. Noise sensitivity was significantly associated with almost all medications, with the exception of the use of antasthmatics, showing an increase in ORs with the level of noise sensitivity, with differences in ORs among countries only for the use of antihypertensive medication. The results also suggested a mediating role of aircraft noise annoyance and a modifying role of both aircraft noise annoyance and noise sensitivity in the association between aircraft noise levels and medication use.

CONCLUSIONS

The present study is consistent with the results of the small number of studies available to date suggesting that both aircraft noise annoyance and noise sensitivity should be taken into account in analyses of the health effects of exposure to aircraft noise.

The role of aircraft noise annoyance and noise sensitivity in the association between aircraft noise levels and hypertension risk: Results of a pooled analysis from seven European countries

INTRODUCTION

Many studies, including the HYENA and the DEBATS studies, showed a significant association between aircraft noise exposure and the risk of hypertension. Few studies have considered aircraft noise annoyance and noise sensitivity as factors of interest, especially in relation to hypertension risk, or as mediating or modifying factors. The present study aims 1) to investigate the risk of hypertension in relation to aircraft noise annoyance or noise sensitivity; and 2) to examine the role of modifier or mediator of these two factors in the association between aircraft noise levels and the risk of hypertension.

METHODS

This study included 6,105 residents of ten European airports from the HYENA and DEBATS studies. Information on aircraft noise annoyance, noise sensitivity, and demographic, socioeconomic and lifestyle factors was collected during an interview performed at home. Participants were classified as hypertensive if they had either blood pressure levels above the WHO cut-off points or physician-diagnosed hypertension in conjunction with the use of antihypertensive medication. Outdoor aircraft noise exposure was estimated for each participant's home address. Poisson regression models with adjustment for potential confounders were used. Interactions between noise exposure and country were tested to consider possible differences between countries.

RESULTS

An increase in aircraft noise levels at night was weekly but significantly associated with an increased risk of hypertension (RR = 1.03, 95% CI 1.01-1.06 for a 10-dB(A) increase in L_night). A significant association was found between aircraft noise annoyance and hypertension risk (RR = 1.06, 95%CI 1.00-1.13 for highly annoyed people compared to those who were not highly annoyed). The risk of hypertension was slightly higher for people highly sensitive to noise compared to people with low sensitivity in the UK (RR = 1.29, 95%CI 1.05-1.59) and in France (RR = 1.11, 95%CI 0.68-1.82), but not in the other countries. The association between aircraft noise levels and the risk of hypertension was higher among highly sensitive participants (RR = 1.00, 95%CI 0.96-1.04; RR = 1.03, 95%CI 0.90-1.11; RR = 1.12, 95%CI 1.01-1.24, with a 10-dB(A) increase in L_night for low, medium, and high sensitive people respectively) or, to a lesser extent, among highly annoyed participants (RR = 1.06, 95%CI 0.95-1.18 for a 10-dB(A) increase in L_night among highly annoyed participants, and RR = 1.02, 95%CI 0.99-1.06 among those not highly annoyed).

CONCLUSIONS

The present study confirms findings in the small number of available studies to date suggesting adverse health effects associated with aircraft noise annoyance and noise sensitivity. The findings also indicate possible modifier effects of aircraft noise annoyance and noise sensitivity in the relationship between aircraft noise levels and the risk of hypertension. However, further investigations are needed to better understand this role using specific methodology and tools related to mediation analysis and causal inference.

Long-term residential road traffic noise and mortality in a Danish cohort

Transportation noise is a growing public health concern worldwide and epidemiological evidence has linked road traffic noise with mortality. However, incongruent effect estimates have been reported between incidence and mortality studies. Therefore, the present study aimed to investigate whether long-term exposure to residential road traffic noise at the most and least exposed façades was associated with all-cause, cardiovascular disease (CVD), ischemic heart disease (IHD), stroke, respiratory, or cancer mortality in a Danish cohort study. In a cohort of 52,758 individuals from Copenhagen and Aarhus, we estimated road traffic noise at the most and least exposed façades, as well as ambient air pollution, at all present and historical residential addresses from 1987 to 2016. Using the Danish cause of death register we identified cause-specific mortality. Analyses were conducted using Cox proportional hazards models. Ten-year time-weighted mean road traffic noise exposure at the most exposed façade was associated with an 8% higher risk for all-cause mortality per interquartile range (IQR; 10.4 dB) higher exposure level (95% CI: 1.05-1.11). Higher risks were also observed for CVD (HR = 1.13, 95% CI: 1.06-1.19) and stroke (HR = 1.11, 95% CI: 0.99-1.25) mortality. Road traffic noise at the least exposed façade (per IQR; 8.4 dB) was associated with CVD (HR = 1.09, 95% CI: 1.03-1.15), IHD (HR = 1.10, 95% CI: 1.01-1.21) and stroke (HR = 1.06, 95% CI: 0.95-1.19) mortality. Results were robust to adjustment for PM_2.5 and NO₂. In conclusion, this study adds to the body of evidence linking exposure to road traffic noise with higher risk of mortality.

Noise exposure and childhood asthma up to adolescence

OBJECTIVE

Increasing evidence indicates aggravation of immune-mediated diseases due to physiological and psychological stress. Noise is a stressor, however, little is known about its effects on children's respiratory health. This study investigates the association between pre- or postnatal road traffic or occupational noise exposure and asthma as well as related symptoms from infancy to adolescence.

METHODS

The study was conducted in the Swedish birth cohort BAMSE, including over 4000 participants followed with repeated questionnaires and clinical tests until 16 years of age. Pre- and postnatal residential road traffic noise was assessed by estimating time-weighted average noise levels at the most exposed façade. Maternal occupational noise exposure during pregnancy was evaluated using a job-exposure-matrix. The associations between noise exposure and asthma-related outcomes were explored using logistic regression and generalised estimating equations.

RESULTS

We observed non-significant associations for asthma ever up to 16 years with residential road traffic noise exposure in infancy ≥55 dB_Lden (adjusted OR = 1.22; 95% CI 0.90-1.65), as well as prenatal occupational noise exposure ≥80 dB_LAeq,8h (1.18, 0.85-1.62). In longitudinal analyses, however, no clear associations between pre- or postnatal exposure to residential road traffic noise, or average exposure to noise since birth, were detected in relation to asthma or wheeze until 16 years.

CONCLUSION

We did not find a clear overall association between exposure to noise during different time periods and asthma or wheeze up to adolescence.

Road Traffic Noise Exposure and Filled Prescriptions for Antihypertensive Medication: A Danish Cohort Study

BACKGROUND

Epidemiological research on effects of transportation noise on incident hypertension is inconsistent.

OBJECTIVES

We aimed to investigate whether residential road traffic noise increases the risk for hypertension.

METHODS

In a population-based cohort of 57,053 individuals 50-64 years of age at enrollment, we identified 21,241 individuals who fulfilled our case definition of filling ≥2 prescriptions and ≥180 defined daily doses of antihypertensive drugs (AHTs) within a year, during a mean follow-up time of 14.0 y. Residential addresses from 1987 to 2016 were obtained from national registers, and road traffic noise at the most exposed façade as well as the least exposed façade was modeled for all addresses. Analyses were conducted using Cox proportional hazards models.

RESULTS

We found no associations between the 10-y mean exposure to road traffic noise and filled prescriptions for AHTs, with incidence rate ratios (IRRs) of 0.999 [95% confidence intervals (CI): 0.980, 1.019)] per 10-dB increase in road traffic noise at the most exposed façade and of 1.001 (95% CI: 0.977, 1.026) at the least exposed façade. Interaction analyses suggested an association with road traffic noise at the least exposed façade among subpopulations of current smokers and obese individuals.

CONCLUSION

The present study does not support an association between road traffic noise and filled prescriptions for AHTs. https://doi.org/10.1289/EHP6273.

Maternal exposure to air pollution during pregnancy and cortisol level in cord blood

Exposure to air pollution has been associated with disorders of the endocrine system and hypothalamic-pituitary-adrenal (HPA) axis; however, the available evidence on these associations is still scarce. This study aimed to investigate, for the first time, the association of exposure to PM₁, PM_2.5, and PM₁₀, as well as traffic indicators (distance to major roads and total street length in different buffers around maternal residential address) during pregnancy with cortisol level in cord blood samples. This cross-sectional study was carried out based on 150 mother-newborn pairs in Sabzevar, Iran (2018). Land use regression models were applied to estimate air pollution exposure during the entire pregnancy at maternal residential addresses. Multiple linear regression models were applied to estimate the association of exposure to air pollution during pregnancy and cord blood cortisol levels, controlled for relevant covariates. There was a significant positive association between exposure to PM_2.5 and PM₁₀ and cortisol levels in cord blood (β = 2.55, 95% confidence intervals (CI) = 0.57, 4.52, P-value = 0.01, and β = 3.09, 95% CI: 1.28, 4.90, P-value < 0.01, respectively). Moreover, there was a significant positive association between total street length in a 100 m buffer around maternal residence and cortisol level. Each one interquartile range (IQR) increase in distance from home to major roads was associated with a -2.58 (95% CI: -4.85, -0.30, P-value = 0.03) decrease in cord blood cortisol level. The median (IQR) of the cord blood cortisol levels for the first and fourth quartiles of distance to major roads were 50.7 (19.5) and 38.2 (20.4) ng/mL, respectively. The associations for total street length in 300 m and 500 m buffers and PM₁ exposure were not statistically significant. Our findings suggest a direct association of exposure to air pollution during pregnancy and cortisol levels at cord blood.

Adverse Cardiovascular Effects of Traffic Noise with a Focus on Nighttime Noise and the New WHO Noise Guidelines

Exposure to traffic noise is associated with stress and sleep disturbances. The World Health Organization (WHO) recently concluded that road traffic noise increases the risk for ischemic heart disease and potentially other cardiometabolic diseases, including stroke, obesity, and diabetes. The WHO report focused on whole-day noise exposure, but new epidemiological and translational field noise studies indicate that nighttime noise, in particular,is an important risk factor for cardiovascular disease (CVD) through increased levels of stress hormones and vascular oxidative stress, leading to endothelial dysfunction and subsequent development of various CVDs. Novel experimental studies found noise to be associated with oxidative stress-induced vascular and brain damage, mediated by activation of the NADPH oxidase, uncoupling of endothelial and neuronal nitric oxide synthase, and vascular/brain infiltration with inflammatory cells. Noise-induced pathophysiology was more pronounced in response to nighttime as compared with daytime noise. This review focuses on the consequences of nighttime noise.

Crucial role for Nox2 and sleep deprivation in aircraft noise-induced vascular and cerebral oxidative stress, inflammation, and gene regulation

Aims

Aircraft noise causes endothelial dysfunction, oxidative stress, and inflammation. Transportation noise increases the incidence of coronary artery disease, hypertension, and stroke. The underlying mechanisms are not well understood. Herein, we investigated effects of phagocyte-type NADPH oxidase (Nox2) knockout and different noise protocols (around-the-clock, sleep/awake phase noise) on vascular and cerebral complications in mice.

Methods and results

C57BL/6j and Nox2^−/− (gp91phox^−/−) mice were exposed to aircraft noise (maximum sound level of 85 dB(A), average sound pressure level of 72 dB(A)) around-the-clock or during sleep/awake phases for 1, 2, and 4 days. Adverse effects of around-the-clock noise on the vasculature and brain were mostly prevented by Nox2 deficiency. Around-the-clock aircraft noise of the mice caused the most pronounced vascular effects and dysregulation of Foxo3/circadian clock as revealed by next generation sequencing (NGS), suggesting impaired sleep quality in exposed mice. Accordingly, sleep but not awake phase noise caused increased blood pressure, endothelial dysfunction, increased markers of vascular/systemic oxidative stress, and inflammation. Noise also caused cerebral oxidative stress and inflammation, endothelial and neuronal nitric oxide synthase (e/nNOS) uncoupling, nNOS mRNA and protein down-regulation, and Nox2 activation. NGS revealed similarities in adverse gene regulation between around-the-clock and sleep phase noise. In patients with established coronary artery disease, night-time aircraft noise increased oxidative stress, and inflammation biomarkers in serum.

Conclusion

Aircraft noise increases vascular and cerebral oxidative stress via Nox2. Sleep deprivation and/or fragmentation caused by noise triggers vascular dysfunction. Thus, preventive measures that reduce night-time aircraft noise are warranted.

Saliva cortisol in relation to aircraft noise exposure: pooled-analysis results from seven European countries

BACKGROUND

Many studies have demonstrated adverse effects of exposure to aircraft noise on health. Possible biological pathways for these effects include hormonal disturbances. Few studies deal with aircraft noise effects on saliva cortisol in adults, and results are inconsistent.

OBJECTIVE

We aimed to assess the effects of aircraft noise exposure on saliva cortisol levels and its variation in people living near airports.

METHODS

This study focused on the 1300 residents included in the HYENA and DEBATS cross-sectional studies, with complete information on cortisol sampling. All the participants followed a similar procedure aiming to collect both a morning and an evening saliva cortisol samples. Socioeconomic and lifestyle information were obtained during a face-to-face interview. Outdoor aircraft noise exposure was estimated for each participant's home address. Associations between aircraft noise exposure and cortisol outcomes were investigated a priori for male and female separately, using linear regression models adjusted for relevant confounders. Different approaches were used to characterize cortisol levels, such as morning and evening cortisol concentrations and the absolute and relative variations between morning and evening levels.

RESULTS

Statistically significant increases of evening cortisol levels were shown in women with a 10-dB(A) increase in aircraft noise exposure in terms of LA_{eq, 16h} (exp(β) = 1.08; CI95% = 1.00-1.16), L_den (exp(β) = 1.09; CI95% = 1.01-1.18), L_night (exp(β) = 1.11; CI95% = 1.02-1.20). A statistically significant association was also found in women between a 10-dB(A) increase in terms of L_night and the absolute variation per hour (exp(β) = 0.90; CI95% = 0.80-1.00). Statistically significant decreases in relative variation per hour were also evidenced in women, with stronger effects with the L_night (exp(β) = 0.89; CI95% = 0.83-0.96) than with other noise indicators. The morning cortisol levels were unchanged whatever noise exposure indicator considered. There was no statistically significant association between aircraft noise exposure and cortisol outcomes in men.

CONCLUSIONS

The results of the present study show statistically significant associations between aircraft noise exposure and evening cortisol levels and related flattening in the (absolute and relative) variations per hour in women. Further biological research is needed to deepen knowledge of the pathway between noise exposure and disturbed hormonal regulation, and specially the difference in effects between genders.

Acute exposure to nocturnal train noise induces endothelial dysfunction and pro-thromboinflammatory changes of the plasma proteome in healthy subjects

Nocturnal train noise exposure has been associated with hypertension and myocardial infarction. It remains unclear whether acute nighttime train exposure may induce subclinical atherosclerosis, such as endothelial dysfunction and other functional and/or biochemical changes. Thus, we aimed to expose healthy subjects to nocturnal train noise and to assess endothelial function, changes in plasma protein levels and clinical parameters. In a randomized crossover study, we exposed 70 healthy volunteers to either background or two different simulated train noise scenarios in their homes during three nights. After each night, participants visited the study center for measurement of vascular function and assessment of other biomedical and biochemical parameters. The three nighttime noise scenarios were exposure to either background noise (control), 30 or 60 train noise events (Noise30 or Noise60), with average sound pressure levels of 33, 52 and 54 dB(A), respectively. Flow-mediated dilation (FMD) of the brachial artery was 11.23 ± 4.68% for control, compared to 8.71 ± 3.83% for Noise30 and 8.47 ± 3.73% for Noise60 (p < 0.001 vs. control). Sleep quality was impaired after both Noise30 and Noise60 nights (p < 0.001 vs. control). Targeted proteomic analysis showed substantial changes of plasma proteins after the Noise60 night, mainly centered on redox, pro-thrombotic and proinflammatory pathways. Exposure to simulated nocturnal train noise impaired endothelial function. The proteomic changes point toward a proinflammatory and pro-thrombotic phenotype in response to nocturnal train noise and provide a molecular basis to explain the increased cardiovascular risk observed in epidemiological noise studies.

A profile of noise sensitivity on the health-related quality of life among young motorcyclists

Introduction:

Motorcycle riders with noise sensitivity (NS) may suffer from degraded health-related quality of life (HRQOL) because they are exposed to acute noise levels on a daily basis.

Materials and Methods:

This study was aimed to identify the relationship between NS and HRQOL among young motorcycle riders (undergraduate university students) aged between 19 and 25 years (n = 301) through a cross-sectional questionnaire-based study, that is, Weinstein noise sensitivity scale and the World Health Organization Quality of Life. The effects of NS on HRQOL were assessed based on gender, the years of motorcycle driving experience, and noise sensitive among groups using one-way analysis of variances with an alpha value of 0.05.

Results:

The results showed no significant difference in NS between males and females. On the other hand, motorcycle driving experience for <4 years displayed a higher tendency toward NS. Moreover, a significantly (P = 0.004) decreasing trend among low, moderate, and high NS with their respective HRQOL was observed, while a high NS showed significantly (P = 0.015) lower scores on the social domain of the quality of life.

Conclusion:

The overall premise of the study has statistical significance and shows that individuals with high NS tend to have degraded HRQOL compared to individuals with low NS. Furthermore, in-depth studies are required from the other demographical background of participants to investigate the motorcyclist’s NS and HRQOL as an integral requirement for the rider’s safety and health.

Environmental noise induces the release of stress hormones and inflammatory signaling molecules leading to oxidative stress and vascular dysfunction-Signatures of the internal exposome

Environmental noise is a well-recognized health risk and part of the external exposome-the World Health Organization estimates that 1 million healthy life years are lost annually in Western Europe alone due to noise-related complications, including increased incidence of hypertension, heart failure, myocardial infarction, and stroke. Previous data suggest that noise works through two paired pathways in a proposed reaction model for noise exposure. As a nonspecific stressor, chronic low-level noise exposure can cause a disruption of sleep and communication leading to annoyance and subsequent sympathetic and endocrine stress responses leading to increased blood pressure, heart rate, stress hormone levels, and in particular more oxidative stress, being responsible for vascular dysfunction and representing changes of the internal exposome. Chronic stress generates cardiovascular risk factors on its own such as increased blood pressure, blood viscosity, blood glucose, and activation of blood coagulation. To this end, persistent chronic noise exposure increases cardiometabolic diseases, including arterial hypertension, coronary artery disease, arrhythmia, heart failure, diabetes mellitus type 2, and stroke. The present review discusses the mechanisms of the nonauditory noise-induced cardiovascular and metabolic consequences, focusing on mental stress signaling pathways, activation of the hypothalamic-pituitary-adrenocortical axis and sympathetic nervous system, the association of these activations with inflammation, and the subsequent onset of oxidative stress and vascular dysfunction. © 2019 BioFactors, 45 (4):495-506, 2019.

The effectiveness of noise interventions in the ICU

PURPOSE OF REVIEW

Excessive noise has direct adverse physiological and psychological effects, and may also have indirect negative health consequences by reducing sleep quality and quantity. This review presents a synthesis of the epidemiology of noise in the ICU, and the potential interventions designed to attenuate noise and protect patients.

RECENT FINDINGS

Noise increases cortisol release, oxygen consumption, and vasoconstriction. ICU noise levels are excessive throughout the 24-h cycle, irrespective of level of intervention or whether the patient is in a side room or open ward. Direct measurement suggests that noise is a substantial contributor to poor sleep quantity and quality in the ICU and is frequently recalled by survivors of critical illness as a negative experience of ICU admission. Noise abatement, environmental masking and pharmacological interventions may all reduce the impact of noise on patients. However, the sustainability of behavioural interventions remains uncertain and high-quality evidence demonstrating the benefit of any intervention on patient-centered outcomes is lacking.

SUMMARY

Noise levels in the ICU are consistently reported to reach levels likely to have both direct and indirect adverse health consequences for both patients and staff. Noise reduction, abating the transmission of noise and pharmacological modulation of the adverse neural effects of noise are all potentially beneficial strategies, although definitive evidence of improved patient-centered outcomes is lacking.

Road traffic noise and markers of adiposity in the Danish Nurse Cohort: A cross-sectional study

BACKGROUND

Studies have suggested that traffic noise is associated with markers of obesity. We investigated the association of exposure to road traffic noise with body mass index (BMI) and waist circumference in the Danish Nurse Cohort.

METHODS

We used data on 15,501 female nurses (aged >44 years) from the nationwide Danish Nurse Cohort who, in 1999, reported information on self-measured height, weight, and waist circumference, together with information on socioeconomic status, lifestyle, work and health. Road traffic noise at the most exposed façade of the residence was estimated using Nord2000 as the annual mean of a weighted 24-h average (L_den). We used multiple linear regression models to examine associations of road traffic noise levels in 1999 (1-year mean) with BMI and waist circumference, adjusting for potential confounders, and evaluated effect modification by degree of urbanization, air pollution levels, night shift work, job strain, sedative use, sleep aid use, and family history of obesity.

RESULTS

We did not observe associations between road traffic noise (per 10 dB increase in the 1-year mean L_den) and BMI (kg/m²) (β: 0.00; 95% confidence interval (CI): -0.07, 0.07) or waist circumference (cm) (β: -0.09; 95% CI: -0.31, 0.31) in the fully adjusted model. We found significant effect modification of job strain and degree of urbanization on the associations between L_den and both BMI and waist circumference. Job strained nurses were associated with a 0.41 BMI-point increase, (95% CI: 0.06, 0.76) and a 1.00 cm increase in waist circumference (95% CI: 0.00, 2.00). Nurses living in urban areas had a statistically significant positive association of L_den with BMI (β: 0.26; 95% CI: 0.11, 0.42), whilst no association was found for nurses living in suburban and rural areas.

CONCLUSION

Our results suggest that road traffic noise exposure in nurses with particular susceptibilities, such as those with job strain, or living in urban areas, may lead to increased BMI, a marker of adiposity.

Long-term transportation noise exposure and incidence of ischaemic heart disease and stroke: a cohort study

BACKGROUND

There is limited evidence from longitudinal studies on transportation noise from different sources and development of ischaemic heart disease (IHD) and stroke.

OBJECTIVES

This cohort study assessed associations between exposure to noise from road traffic, railway or aircraft and incidence of IHD and stroke.

METHODS

In a cohort of 20 012 individuals from Stockholm County, we estimated long-term residential exposure to road traffic, railway and aircraft noise. National Patient and Cause-of-Death Registers were used to identify IHD and stroke events. Information on risk factors was obtained from questionnaires and registers. Adjusted HR for cardiovascular outcomes related to source-specific noise exposure were computed using Cox proportional hazards regression.

RESULTS

No clear or consistent associations were observed between transportation noise and incidence of IHD or stroke. However, noise exposure from road traffic and aircraft was related to IHD incidence in women, with HR of 1.11 (95% CI 1.00 to 1.22) and 1.25 (95% CI 1.09 to 1.44) per 10 dB L_den, respectively. For both sexes taken together, we observed a particularly high risk of IHD in those exposed to all three transportation noise sources at≥45 dB L_den, with a HR of 1.57 (95% CI 1.06 to 2.32), and a similar tendency for stroke (HR 1.42; 95% CI 0.87 to 2.32).

CONCLUSION

No overall associations were observed between transportation noise exposure and incidence of IHD or stroke. However, there appeared to be an increased risk of IHD in women exposed to road traffic or aircraft noise as well as in those exposed to multiple sources of transportation noise.

Full-time exposure to occupational noise during pregnancy was associated with reduced birth weight in a nationwide cohort study of Swedish women

Noise is a common exposure in the occupational work environment. Earlier studies of occupational noise and pregnancy outcome are few and show mixed results. To investigate if objectively assessed exposure to occupational noise during pregnancy is associated with reduced intrauterine growth and/or preterm birth a nationwide cohort study of 857,010 single births was initiated. Individual information on occupation and risk factors was retrieved from prenatal care interviews at pregnancy week 10. Occupational noise was classified into three exposure categories <75, 75-85, >85 dBA by a job exposure matrix. Odds ratios were adjusted for BMI, smoking, parity, education, physically strenuous work and low job control. Exposure to high (>85 dBA) levels of occupational noise throughout the pregnancy (full time workers) was associated with an increased risk of the child being born small for gestational age, OR 1.44 (95% CI 1.01 to 2.03) compared to noise exposure <75 dBA. A similar increase was seen for low birth weight OR 1.36 (95% CI 1.03 to 1.80) for high levels of noise. No clear association was seen for preterm birth. No consistent effects on birth outcome was observed in women who had worked part-time or were on leave of absence >21 days (median). In summary, full-time exposure to high levels of noise during pregnancy was associated with a slightly reduced fetal growth but not with preterm birth. The effect of intermediate occupational noise exposure (75-85 dBA) showed a small, but statistically increased risk for all studied birth outcomes. The study strengthens the evidence that pregnant women should not be long-term exposed to high levels >85 dBA of occupational noise during pregnancy. Intermediate exposure should be studied further.

Assessment of noise in the airplane cabin environment

OBJECTIVE

To measure sound levels in the aircraft cabin during different phases of flight.

METHODS

Sound level was measured on 200 flights, representing six aircraft groups using continuous monitors. A linear mixed-effects model with random intercept was used to test for significant differences in mean sound level by aircraft model and across each flight phase as well as by flight phase, airplane type, measurement location and proximity to engine noise.

RESULTS

Mean sound levels across all flight phases and aircraft groups ranged from 37.6 to >110 dB(A) with a median of 83.5 dB(A). Significant differences in noise levels were also observed based on proximity to the engines and between aircraft with fuselage- and wing mounted engines. Nine flights (4.5%) exceeded the recommended 8-h TWA exposure limit of 85 dB(A) by the NIOSH and ACGIH approach, three flights (1.5%) exceeded the 8-h TWA action level of 85 dB(A) by the OSHA approach, and none of the flights exceeded the 8-h TWA action level of 90 dB(A) by the OSHA PEL approach.

CONCLUSIONS

Additional characterization studies, including personal noise dosimetry, are necessary to document accurate occupational exposures in the aircraft cabin environment and identify appropriate response actions. FAA should consider applying the more health-protective NIOSH/ACGIH occupational noise recommendations to the aircraft cabin environment.