Transportation noise impairs cardiovascular function without altering sleep: The importance of autonomic arousals.

AIMS: Chronic exposure to nocturnal transportation noise has been linked to cardiovascular disorders with sleep impairment as the main mediator. Here we examined whether nocturnal transportation noise affects the main stress pathways, and whether it relates to changes in the macro and micro structure of sleep. METHODS AND RESULTS: Twenty-six young healthy participants (12 women, 24.6 ± 0.7 years, mean ± SE) spent five consecutive 24-h days and one last morning in the laboratory. The first (baseline) and last (recovery) nights comprised a quiet ambient scenario. In-between, four different noise scenarios (low/medium/high intermittent road or rail scenarios with an identical equivalent continuous sound level of 45 dB) were randomly presented during the 8-h nights. Participants felt more annoyed from the transportation noise scenarios compared to the quiet ambient scenario played back during the baseline and recovery nights (F5,117 = 10.2, p < 0.001). Nocturnal transportation noise did not significantly impact polysomnographically assessed sleep macrostructure, blood pressure, nocturnal catecholamine levels and morning cytokine levels. Evening cortisol levels increased after sleeping with highly intermittent road noise compared to baseline (p = 0.002, noise effect: F4,83 = 4.0, p = 0.005), a result related to increased cumulative duration of autonomic arousals during the noise nights (F5,106 = 3.4, p < 0.001; correlation: rpearson = 0.64, p = 0.006). CONCLUSION: Under controlled laboratory conditions, highly intermittent nocturnal road noise exposure at 45 dB increased the cumulative duration of autonomic arousals during sleep and next-day evening cortisol levels. Our results indicate that, without impairing sleep macrostructure, nocturnal transportation noise of 45 dB is a physiological stressor that affects the hypothalamic-pituitary-adrenal axis during the following day in healthy young good sleepers.

A systematic analysis of mutual effects of transportation noise and air pollution exposure on myocardial infarction mortality: a nationwide cohort study in Switzerland.

AIMS: The present study aimed to disentangle the risk of the three major transportation noise sources-road, railway, and aircraft traffic-and the air pollutants NO2 and PM2.5 on myocardial infarction (MI) mortality in Switzerland based on high quality/fine resolution exposure modelling. METHODS AND RESULTS: We modelled long-term exposure to outdoor road traffic, railway, and aircraft noise levels, as well as NO2 and PM2.5 concentration for each address of the 4.40 million adults (>30 years) in the Swiss National Cohort (SNC). We investigated the association between transportation noise/air pollution exposure and death due to MI during the follow-up period 2000-08, by adjusting noise [Lden(Road), Lden(Railway), and Lden(Air)] estimates for NO2 and/or PM2.5 and vice versa by multipollutant Cox regression models considering potential confounders. Adjusting noise risk estimates of MI for NO2 and/or PM2.5 did not change the hazard ratios (HRs) per 10 dB increase in road traffic (without air pollution: 1.032, 95% CI: 1.014-1.051, adjusted for NO2 and PM2.5: 1.034, 95% CI: 1.014-1.055), railway traffic (1.020, 95% CI: 1.007-1.033 vs. 1.020, 95% CI: 1.007-1.033), and aircraft traffic noise (1.025, 95% CI: 1.006-1.045 vs. 1.025, 95% CI: 1.005-1.046). Conversely, noise adjusted HRs for air pollutants were lower than corresponding estimates without noise adjustment. Hazard ratio per 10 µg/m³ increase with and without noise adjustment were 1.024 (1.005-1.043) vs. 0.990 (0.965-1.016) for NO2 and 1.054 (1.013-1.093) vs. 1.019 (0.971-1.071) for PM2.5. CONCLUSION: Our study suggests that transportation noise is associated with MI mortality, independent from air pollution. Air pollution studies not adequately adjusting for transportation noise exposure may overestimate the cardiovascular disease burden of air pollution.

Noise in the Operating Room Distracts Members of the Surgical Team. An Observational Study.

BACKGROUND: Noise pollution in operation rooms may distract the surgical team members. In particular during phases of high task complexity, noise can jeopardize concentration. Phases of high complexity are related to task specificities and may thus be different for different members of the surgical team. STUDY DESIGN: Noise exposure was measured during 110 open abdominal surgeries. Distinguishing three phases (opening, main phase, and closing), noise was related to self-report of distraction levels by main and secondary surgeons, scrub nurses and anesthetists. RESULTS: Noise pollution was higher than recommended levels for concentrated work. Adjusted for duration, surgical type, and difficulty of the surgery, results showed that second surgeons are more likely distracted when noise pollution was high in the main phase; and anesthetists are more likely distracted when noise pollution was high during the closing phase. Main surgeons' and scrub nurses' concentration was not impaired by measured noise levels. CONCLUSIONS: In phases with higher concentration demands, noise pollution was particularly distracting for second surgeons and anesthetist, corresponding to their specific task demands (anesthetists) and experience (second surgeons). Reducing noise levels particularly in the main and closing phase of the surgery may reduce concentration impairments.

Transportation noise exposure and cardiovascular mortality: a nationwide cohort study from Switzerland.

Most studies published to date consider single noise sources and the reported noise metrics are not informative about the peaking characteristics of the source under investigation. Our study focuses on the association between cardiovascular mortality in Switzerland and the three major transportation noise sources-road, railway and aircraft traffic-along with a novel noise metric termed intermittency ratio (IR), expressing the percentage contribution of individual noise events to the total noise energy from all sources above background levels. We generated Swiss-wide exposure models for road, railway and aircraft noise for 2001. Noise from the most exposed façade was linked to geocodes at the residential floor height for each of the 4.41 million adult (>30 y) Swiss National Cohort participants. For the follow-up period 2000-2008, we investigated the association between all noise exposure variables [Lden(Road), Lden(Rail), Lden(Air), and IR at night] and various cardiovascular primary causes of death by multipollutant Cox regression models adjusted for potential confounders including NO2. The most consistent associations were seen for myocardial infarction: adjusted hazard ratios (HR) (95% CI) per 10 dB increase of exposure were 1.038 (1.019-1.058), 1.018 (1.004-1.031), and 1.026 (1.004-1.048) respectively for Lden(Road), Lden(Rail), and Lden(Air). In addition, total IR at night played a role: HRs for CVD were non-significant in the 1st, 2nd and 5th quintiles whereas they were 1.019 (1.002-1.037) and 1.021 (1.003-1.038) for the 3rd and 4th quintiles. Our study demonstrates the impact of all major transportation noise sources on cardiovascular diseases. Mid-range IR levels at night (i.e. between continuous and highly intermittent) are potentially more harmful than continuous noise levels of the same average level.

Noise exposure-response relationships established from repeated binary observations: Modeling approaches and applications.

Noise exposure-response relationships are used to estimate the effects of noise on individuals or a population. Such relationships may be derived from independent or repeated binary observations, and modeled by different statistical methods. Depending on the method by which they were established, their application in population risk assessment or estimation of individual responses may yield different results, i.e., predict "weaker" or "stronger" effects. As far as the present body of literature on noise effect studies is concerned, however, the underlying statistical methodology to establish exposure-response relationships has not always been paid sufficient attention. This paper gives an overview on two statistical approaches (subject-specific and population-averaged logistic regression analysis) to establish noise exposure-response relationships from repeated binary observations, and their appropriate applications. The considerations are illustrated with data from three noise effect studies, estimating also the magnitude of differences in results when applying exposure-response relationships derived from the two statistical approaches. Depending on the underlying data set and the probability range of the binary variable it covers, the two approaches yield similar to very different results. The adequate choice of a specific statistical approach and its application in subsequent studies, both depending on the research question, are therefore crucial.

Short-term annoyance reactions to stationary and time-varying wind turbine and road traffic noise: A laboratory study.

Current literature suggests that wind turbine noise is more annoying than transportation noise. To date, however, it is not known which acoustic characteristics of wind turbines alone, i.e., without effect modifiers such as visibility, are associated with annoyance. The objective of this study was therefore to investigate and compare the short-term noise annoyance reactions to wind turbines and road traffic in controlled laboratory listening tests. A set of acoustic scenarios was created which, combined with the factorial design of the listening tests, allowed separating the individual associations of three acoustic characteristics with annoyance, namely, source type (wind turbine, road traffic), A-weighted sound pressure level, and amplitude modulation (without, periodic, random). Sixty participants rated their annoyance to the sounds. At the same A-weighted sound pressure level, wind turbine noise was found to be associated with higher annoyance than road traffic noise, particularly with amplitude modulation. The increased annoyance to amplitude modulation of wind turbines is not related to its periodicity, but seems to depend on the modulation frequency range. The study discloses a direct link of different acoustic characteristics to annoyance, yet the generalizability to long-term exposure in the field still needs to be verified.

Auditory and non-auditory effects of noise on health.

Noise is pervasive in everyday life and can cause both auditory and non-auditory health effects. Noise-induced hearing loss remains highly prevalent in occupational settings, and is increasingly caused by social noise exposure (eg, through personal music players). Our understanding of molecular mechanisms involved in noise-induced hair-cell and nerve damage has substantially increased, and preventive and therapeutic drugs will probably become available within 10 years. Evidence of the non-auditory effects of environmental noise exposure on public health is growing. Observational and experimental studies have shown that noise exposure leads to annoyance, disturbs sleep and causes daytime sleepiness, affects patient outcomes and staff performance in hospitals, increases the occurrence of hypertension and cardiovascular disease, and impairs cognitive performance in schoolchildren. In this Review, we stress the importance of adequate noise prevention and mitigation strategies for public health.

ICBEN review of research on the biological effects of noise 2011-2014.

The mandate of the International Commission on Biological Effects of Noise (ICBEN) is to promote a high level of scientific research concerning all aspects of noise-induced effects on human beings and animals. In this review, ICBEN team chairs and co-chairs summarize relevant findings, publications, developments, and policies related to the biological effects of noise, with a focus on the period 2011-2014 and for the following topics: Noise-induced hearing loss; nonauditory effects of noise; effects of noise on performance and behavior; effects of noise on sleep; community response to noise; and interactions with other agents and contextual factors. Occupational settings and transport have been identified as the most prominent sources of noise that affect health. These reviews demonstrate that noise is a prevalent and often underestimated threat for both auditory and nonauditory health and that strategies for the prevention of noise and its associated negative health consequences are needed to promote public health.

Awakening effects of church bell noise: geographical extrapolation of the results of a polysomnographic field study 1.

Based on a previously published exposure-effect model of Electroencephalography (EEG)-awakening reactions (AWR) due to nightly church bell noise events, as well as on geocoded building and population data, we estimated the total number of the church bell noise induced awakenings on the population of the Canton of Zurich, in Switzerland. The calculated mean number of EEG awakenings per person in the studied region, triggered by church bell ringing, varied between 0 and about 5.5 per night. The results suggest that up to 120-150 m distance from churches, on average more than one additional EEG awakening occurs per night per person. An estimated 2.5-3.5 percent of the population in the Canton of Zurich experiences at least one additional awakening per night due to church bell noise. To provide a simple decision support tool for authorities that consider limiting bell ringing in the night in some form, we simulated different scenarios to estimate the effects of different sound attenuation measures at the belfry as well as the effects of different lengths and positions of nocturnal bell ringing suspension periods. The number of awakenings could be reduced by more than 99 percent by, for example, suspending church bell ringing between midnight and 06 h in the morning. A reduction of the number of AWRs of about 75 percent could be achieved by reducing the sound-pressure levels of bells by 5 dB.

How Do Road Traffic Noise and Residential Greenness Correlate with Noise Annoyance and Long-Term Stress? Protocol and Pilot Study for a Large Field Survey with a Cross-Sectional Design.

Urban areas are continuously growing, and densification is a frequent strategy to limit urban expansion. This generally entails a loss of green spaces (GSs) and an increase in noise pollution, which has negative effects on health. Within the research project RESTORE (Restorative potential of green spaces in noise-polluted environments), an extended cross-sectional field study in the city of Zurich, Switzerland, is conducted. The aim is to assess the relationship between noise annoyance and stress (self-perceived and physiological) as well as their association with road traffic noise and GSs. A representative stratified sample of participants from more than 5000 inhabitants will be contacted to complete an online survey. In addition to the self-reported stress identified by the questionnaire, hair cortisol and cortisone probes from a subsample of participants will be obtained to determine physiological stress. Participants are selected according to their dwelling location using a spatial analysis to determine exposure to different road traffic noise levels and access to GSs. Further, characteristics of individuals as well as acoustical and non-acoustical attributes of GSs are accounted for. This paper presents the study protocol and reports the first results of a pilot study to test the feasibility of the protocol.

Response to "Comments on 'A field study of the exposure-annoyance relationship of military shooting noise' " [J. Acoust. Soc. Am. 127, 2301-2311 (2010)] (L).

This letter is a response to Meyer's recent paper ["Comment on 'A field study of the exposure-annoyance relationship of military shooting noise,' "J. Acoust. Soc. Am. 130, 677-678 (2011)]. The authors describe that "explained variance" in noise annoyance surveys can mean different things and that the fit parameters of the statistical models reported in the commented article are well within an expectable range. It is discussed that non-dose-related factors for the prediction of noise annoyance have become increasingly important in the last years and deserve to be more thoroughly studied.

Effects of environmental noise on sleep.

This paper summarizes the findings from the past 3 year's research on the effects of environmental noise on sleep and identifies key future research goals. The past 3 years have seen continued interest in both short term effects of noise on sleep (arousals, awakenings), as well as epidemiological studies focusing on long term health impacts of nocturnal noise exposure. This research corroborated findings that noise events induce arousals at relatively low exposure levels, and independent of the noise source (air, road, and rail traffic, neighbors, church bells) and the environment (home, laboratory, hospital). New epidemiological studies support already existing evidence that night-time noise is likely associated with cardiovascular disease and stroke in the elderly. These studies collectively also suggest that nocturnal noise exposure may be more relevant for the genesis of cardiovascular disease than daytime noise exposure. Relative to noise policy, new effect-oriented noise protection concepts, and rating methods based on limiting awakening reactions were introduced. The publications of WHO's ''Night Noise Guidelines for Europe'' and ''Burden of Disease from Environmental Noise'' both stress the importance of nocturnal noise exposure for health and well-being. However, studies demonstrating a causal pathway that directly link noise (at ecological levels) and disturbed sleep with cardiovascular disease and/or other long term health outcomes are still missing. These studies, as well as the quantification of the impact of emerging noise sources (e.g., high speed rail, wind turbines) have been identified as the most relevant issues that should be addressed in the field on the effects of noise on sleep in the near future.

Critical appraisal of methods for the assessment of noise effects on sleep.

Various sleep measurement techniques have been applied in past studies on the effects of environmental noise on sleep, complicating comparisons between studies and the derivation of pooled exposure-response relationships that could inform policy and legislation. To date, a consensus on a standard measurement technique for the assessment of environmental noise effects on sleep is missing. This would be desirable to increase comparability of future studies. This manuscript provides a detailed description of the sleep process, typical indicators of disturbed sleep, and how noise interferes with sleep. It also describes and discusses merits and drawbacks of five established methods commonly used for the assessment of noise effects on sleep (i.e., polysomnography, actigraphy, electrocardiography, behaviorally confirmed awakenings, and questionnaires). Arguments supporting the joint use of actigraphy and a single channel electrocardiogram as meaningful, robust, and inexpensive methods that would allow for the investigation of large representative subject samples are presented. These could be used as a starting point for the generation of an expert consensus.

Lowering urban speed limits to 30 km/h reduces noise annoyance and shifts exposure-response relationships: Evidence from a field study in Zurich.

BACKGROUND: The city of Zurich progressively pursuits a strategy of reducing road traffic noise by lowering the speed limit to 30 km/h on street sections that exceed the legal noise limits. Aim of this study was to evaluate the effects of the reduced speed limit on noise levels (Lday and Lnight), noise annoyance, self-reported sleep disturbance, perceived road safety, and in particular, to elucidate if the reduced speed limit leads to a shift of exposure-response relationships towards lower effects. METHODS: We surveyed about 1300 randomly sampled inhabitants, in a repeated measures study, before and after the speed rule changeover from 50 km/h to 30 km/h along 15 city street sections, by postal questionnaire. Concurrently, individual noise exposure calculations based on traffic counts and on-site speed measurements were carried out before and after the changeover. RESULTS: Road traffic noise Leq's at the loudest façade point dropped by an average of 1.6 dB during day and 1.7 dB at night. A statistically significant decrease of noise annoyance and of self-reported sleep disturbances was observed, as well as a moderate but significant increase of perceived road safety. Most importantly, the exposure-response relationships for annoyance and sleep disturbance were shifted towards lower effects in the 30 km/h condition by, depending on receiver point, between about 2 dB and 4 dB during the day and about 4 dB at night, indicating lower effects at the same average level. This is a hint that, in addition to lower average exposure levels alone, other factors related to the lower driving speed additionally reduce noise annoyance and sleep disturbance. CONCLUSIONS: City dwellers probably benefit from traffic speed reductions to a greater degree than would be expected from the reduction in average level attained by the lower driving speed alone.

Does the Macro-Temporal Pattern of Road Traffic Noise Affect Noise Annoyance and Cognitive Performance?

Noise annoyance is usually estimated based on time-averaged noise metrics. However, such metrics ignore other potentially important acoustic characteristics, in particular the macro-temporal pattern of sounds as constituted by quiet periods (noise breaks). Little is known to date about its effect on noise annoyance and cognitive performance, e.g., during work. This study investigated how the macro-temporal pattern of road traffic noise affects short-term noise annoyance and cognitive performance in an attention-based task. In two laboratory experiments, participants worked on the Stroop task, in which performance relies predominantly on attentional functions, while being exposed to different road traffic noise scenarios. These were systematically varied in macro-temporal pattern regarding break duration and distribution (regular, irregular), and played back with moderate LAeq of 42-45 dB(A). Noise annoyance ratings were collected after each scenario. Annoyance was found to vary with the macro-temporal pattern: It decreased with increasing total duration of quiet periods. Further, shorter but more regular breaks were somewhat less annoying than longer but irregular breaks. Since Stroop task performance did not systematically vary with different noise scenarios, differences in annoyance are not moderated by experiencing worsened performance but can be attributed to differences in the macro-temporal pattern of road traffic noise.

Effects of noise from non-traffic-related ambient sources on sleep: review of the literature of 1990-2010.

This article reviews the literature about the effects of specific non-traffic-related ambient noise sources on sleep that appeared in the last two decades. Although everybody is faced with noise of non-traffic and non-industry origin (e.g. sounds made by neighbors, talk, laughter, music, slamming doors, structural equipment, ventilation, heat pumps, noise from animals, barking dogs, outdoor events etc.), little scientific knowledge exists about its effects on sleep. The findings of the present extensive literature search and review are as follows: Only a small number of surveys, laboratory and field studies about mainly neighborhood, leisure and animal noise have been carried out. Most of them indicate that ambient noise has some effect on human sleep. However, a quantitative meta-analysis and comparison is not possible due to the small number of studies available and at times large differences in quality.

Pooling and Comparing Noise Annoyance Scores and "High Annoyance" (HA) Responses on the 5-Point and 11-Point Scales: Principles and Practical Advice.

The use of different noise annoyance scales across studies and socio-acoustic surveys, in particular the popular 5-point verbal and 11-point numerical scales, has made the evaluation, comparison, and pooling of noise annoyance responses among studies a taxing issue. This is particularly the case when "high annoyance" (HA) responses need to be compared and when the original studies used different scales; thus, there are different so-called cutoff points that define the part of the scale that indicates the HA status. This paper provides practical guidance on pooling and comparing the respective annoyance data in both the linear and logistic regression context in a statistically adequate manner. It caters to researchers who want to carry out pooled analyses on annoyance data that have been collected on different scales or need to compare exposure-HA relationships between the 5-point and 11-point scales. The necessary simulation of a cutoff point non-native to an original scale can be achieved with a random assignment approach, which is exemplified in the paper using original response data from a range of recent noise annoyance surveys. A code example in the R language is provided for easy implementation of the pertinent procedures with one's own survey data. Lastly, the not insignificant limitations of combining and/or comparing responses from different noise annoyance scales are discussed.

A field study of the exposure-annoyance relationship of military shooting noise.

This article reports a field study on noise annoyance from military shooting with small, midsize, and heavy weapons that was carried out among 1002 residents living near eight different training grounds of the Swiss army. The goal of the study was to derive the exposure-annoyance relationship for military shooting noise in communities in the vicinity of average military training grounds. Annoyance was determined in a telephone survey by means of the 5-point verbal and 11-point numerical annoyance scale recommended by the International Commission on Biological Effects of Noise. Exposure was calculated using acoustical source models of weapons and numbers of shots fired, as recorded by the army. Annoyance predictor variables investigated were L(AE), L(CE), L(CE)-L(AE), number of shots above threshold, as well as individual moderators. Exposure-annoyance relationships were modeled by means of linear and logistic regression analyses. The sound exposure level L(E) of shooting noise better explained variations in annoyance than other operational and/or acoustical predictors. Annoyance on the 5-point scale was more closely related to noise exposure than expressed on the 11-point scale. The inclusion of the C-A frequency weighting difference as a second explaining variable, as suggested earlier, did not substantially enhance the predictability of high annoyance.

Residential green is associated with reduced annoyance to road traffic and railway noise but increased annoyance to aircraft noise exposure.

BACKGROUND: In recent years, residential green and availability of neighbourhood green spaces came into focus as a potential means to reduce transportation noise annoyance. Literature suggests that various characteristics of residential green may play a role, namely, greenness of the residential areas as quantified by the normalized difference vegetation index (NDVI), visible vegetation from home, and the presence of public green spaces as identified by land use classification data (LU-green), as well as their accessibility and noise pollution (i.e., transportation noise exposure within green areas, how loud/quiet they are). So far, studies mostly focused on road traffic noise in urban areas. OBJECTIVE: We investigated the effects of residential green on noise annoyance, accounting for different transportation noise sources as well as for the degree of urbanisation. METHODS: We complemented the data set of the recent Swiss SiRENE survey on road traffic, railway and aircraft noise annoyance with a wide range of "green" metrics, and investigated their association with annoyance by means of logistic regression analysis (generalized estimating equations). RESULTS: Increasing residential green was found to be associated with reduced road traffic and railway noise annoyance, but increased aircraft noise annoyance. The overall effect corresponded to equivalent level reductions of about 6 dB for road traffic and 3 dB for railway noise, but to an increase of about 10 dB for aircraft noise, when residential green increased from "not much green" (5th percentile of the study sample distribution) to "a lot of green" (95th percentile). Overall, NDVI and LU-green were particularly strongly linked to annoyance. The effects of visible vegetation from home and accessibility and/or quietness of green spaces were, overall, less strong, but depended on the degree of urbanisation. For road traffic noise, visible vegetation and accessibility of green spaces seem to particularly strongly reduce annoyance in cities, while quiet green spaces are more effective in rural areas. CONCLUSIONS: Our study emphasizes that residential green should be fostered by city planners, particularly in densely populated areas.