Showing papers by "Mathias Basner published in 2010"

Effects of nocturnal aircraft noise on cognitive performance in the following morning: dose-response relationships in laboratory and field.

Abstract: Nocturnal aircraft noise disturbs sleep and impairs recuperation. We investigated in laboratory and field studies whether noise-induced sleep fragmentation is associated with performance impairments in a psychomotor vigilance task (PVT) and a memory search task. In the laboratory, 112 participants were exposed to aircraft noise during 9 consecutive nights. In the field, 64 participants were examined during 9 consecutive nights in the vicinity of Cologne/Bonn airport. Reaction time, signal detection performance and subjective task load were recorded. Dose–response relationships showed significant, linear impairments in reaction times. In the laboratory, reaction time in PVT increased with 0.13 ms/dB equivalent noise level (LAeq) plus 0.02 ms/noise event. In the field study, reaction time increased with 0.3 ms/dB LAeq. Participants worked significantly less accurate after nocturnal noise exposure. Influences of LAeq and number of noise events on daytime performance were small but consistent and significant, stressing the potential public health impact of nocturnal noise exposure.

Aircraft noise effects on sleep: Mechanisms, mitigation and research needs

Abstract: There is an ample number of laboratory and field studies which provide sufficient evidence that aircraft noise disturbs sleep and, depending on traffic volume and noise levels, may impair behavior and well-being during the day. Although clinical sleep disorders have been shown to be associated with increased risk of cardiovascular diseases, only little is known about the long-term effects of aircraft noise disturbed sleep on health. National and international laws and guidelines try to limit aircraft noise exposure facilitating active and passive noise control to prevent relevant sleep disturbances and its consequences. Adopting the harmonized indicator of the European Union Directive 2002/49/EC, the WHO Night Noise Guideline for Europe (NNG) defines four Lnight , outside ranges associated with different risk levels of sleep disturbance and other health effects ( 55 dBA). Although traffic patterns differing in number and noise levels of events that lead to varying degrees of sleep disturbance may result in the same Lnight , simulations of nights with up to 200 aircraft noise events per night nicely corroborate expert opinion guidelines formulated in WHO's NNG. In the future, large scale field studies on the effects of nocturnal (aircraft) noise on sleep are needed. They should involve representative samples of the population including vulnerable groups like children and chronically ill subjects. Optimally, these studies are prospective in nature and examine the long-term consequences of noise-induced sleep disturbances. Furthermore, epidemiological case-control studies on the association of nocturnal (aircraft) noise exposure and cardiovascular disease are needed. Despite the existing gaps in knowledge on long-term health effects, sufficient data are available for defining limit values, guidelines and protection concepts, which should be updated with the availability of new data.

Aircraft Noise Indexes for Effect Oriented Noise Assessment

Abstract: This article discusses aircraft noise effect assessment with noise effect indexes, such as have recently been developed for noise monitoring purposes at the airports of Zurich and Frankfurt. Aircraft noise indexes are noise assessment instruments that express the overall effects of aircraft noise as a single figure which reflects the total amount of people that are in some way affected by the noise of a particular airport. By accounting for the most important effect measures (such as annoyance or awakening reactions) and by weighting these measures according to the population density at each grid point within a defined geographic perimeter, noise effect indexes provide residents and authorities with an integral picture of the total noise effect. The paper reviews basic features of noise effect indexes and reports about the development and the current practical application of such indexes. Moreover, it points to specific not yet fully resolved issues such as accounting for the diurnal variation of noise effects, the definition of calculation perimeters, and the weighting of day and night effects including the question of unification of different effect measures into one index.

Markov processes for the prediction of aircraft noise effects on sleep.

Abstract: Background. Aircraft noise disturbs sleep and impairs recuperation. Authorities plan to expand Frankfurt airport. Objective. To quantitatively assess the effects of a traffic curfew (11 PM to 5 AM) at Frankfurt Airport on sleep structure. Design. Experimental sleep study; polysomnography for 13 consecutive nights. Setting. Sleep laboratory. Subjects. 128 healthy subjects, mean age (SD) 38 (13) years, range 19 to 65, 59% female. Intervention. Exposure to aircraft noise via loudspeakers. Measurements. A 6-state Markov state transition sleep model was used to simulate 3 noise scenarios with first-order Monte Carlo simulations: 1) 2005 traffic at Frankfurt Airport, 2) as simulation 1 but flights between 11 PM and 5 AM cancelled, and 3) as simulation 2, with flights between 11 PM and 5 AM from simulation 1 rescheduled to periods before 11 PM and after 5 AM. Probabilities for transitions between sleep stages were estimated with autoregressive multinomial logistic regression. Results. Compared to a night without...

Is Time for Sleep Declining Among Americans

Abstract: THE MILLIONS OF AMERICANS WHO DO NOT GET ENOUGH SLEEP NIGHT AFTER NIGHT RISK DEVELOPING CUMULATIVE NEUROBEHAVIORAL DEFICITS and experiencing sleepiness-related errors and accidents.1–3 Since reduced sleep duration has frequently been associated with a higher prevalence of obesity,4 morbidity, and mortality,5 these people may also be incurring health risks, although it remains uncertain whether these relationships are causal. In this issue of SLEEP, Knutson and colleagues6 attempt to address the question of whether sleep duration among Americans has been steadily decreasing, using time use studies. Although many who believe Americans are sleeping less each decade attribute this to a culture that increasingly perceives sleep as a flexible commodity that can be exchanged for waking activities considered more essential or of greater value,7 the investigation of secular trends in the prevalence of sleep duration is complicated by inconsistent methodologies for establishing sleep time using surveys. This is what makes the study of Knutson et al.,6 which focuses on 8 nationally representative time use studies performed between 1975 and 2006, unique and important. Looking at the combined data of all studies with more than 73,000 respondents and adjusting for many important confounders, they find a small and statistically non-significant increase in the odds of being a short sleeper (< 6 hours) from 1975 to 2006 (OR 1.08, P = 0.29). Also, there was no strictly monotonous increase in the prevalence of short sleepers across years, with the highest prevalence being observed in the 1998-99 survey (11.8%) followed by the 1985 survey (9.9%). It is unclear how much of the differences among studies in findings of sleep duration is due to residual differences in survey methodology (i.e. subject sampling, data sampling, or activity coding). This stresses the importance of consistent study methodology for the investigation of secular trends in sleep time. With constantly emerging new ideas and research avenues, it is by no means trivial to hold on to a once established study design. The American Time Use Survey (ATUS) completed its 6th year in 2008, and there is a 22 page document addressing the changes between 2003-2008 data files. Nevertheless, it was extremely important that the 2008 initiative to discontinue the ATUS could be stopped, so that this study will likely provide us with important insight into secular trends in sleep time and waking activity time in the future. However, the ATUS should not be our only resource. There is a wealth of prospective studies collecting data on relevant health outcomes and, sometimes, also on sleep quality and quantity. However, different surveys often also use different questions to assess sleep quality and quantity. For example, the boundaries of sleep time categories vary greatly between studies and complicate merging or comparing data from different studies. The sleep research community should propagate a set of questions addressing both sleep quality and quantity that, comparable to the SF-36 for quality of life, could be routinely used in different surveys and would guarantee comparability across surveys and over time. Does the fact that Knutson et al.6 found no significant secular trend in the prevalence of short sleepers reassure us that sleep time is not decreasing among Americans? It certainly does not give us a reason to panic, but the fact that sleep time has not significantly decreased during the past 30 years does not diminish the public health relevance of chronic partial sleep deprivation. As Knutson et al.6 correctly point out time use surveys greatly overestimate sleep time, because both daytime sleep and activities that usually do not qualify as sleep (e.g., falling asleep, dozing off, waking up) are coded as sleep. It is likely that time use surveys may overestimate physiologic sleep by approximately two hours.7,8 Therefore, as Knutson et al.6 discuss correctly, the proportion of the population sleeping less than 6 hours per night may be significantly higher than the time use survey based estimates of 7.5% to 11.8%. Furthermore, when Knutson et al. restricted their analysis to full-time workers, there was a significant secular trend in the odds of being a short sleeper (OR 1.19, P = 0.05). This corroborates results of previous studies showing that work is the dominant waking activity exchanged for (less) sleep,7 and it designates full-time workers as a group at risk for short sleep and its related consequences. The question remains why large parts of the population hazard the consequences of chronic sleep debt? First, many studies have demonstrated a large variability of individual sleep need,9 so we have to acknowledge the fact that at least some of the short sleepers actually do not need more sleep. Second, a 14-day study on chronic partial sleep deprivation1 suggests that those who do need more sleep simply may have habituated to feeling sleepy; although objective measures of neurobehavioral performance deteriorated continuously with time in study in the group allowed 4 or 6 hours of sleep per night, subjective assessments of sleepiness saturated quickly and showed only minor increases during days 4 to 14 of restriction. It is possible, therefore, that many of the short sleepers may have “forgotten” how well they could feel and perform if they satisfied their individual sleep need. Third, people differ in their position of circadian phase, with larks and owls representing the extremes. Especially late phase chronotypes may accumulate a sleep debt during the week, as these individuals may have to get up early due to social demands without being able to advance their circadian controlled sleep-onset. This misalignment of biological and social time was recently coined “social jet lag” by Roonneberg and coworkers.10 However, even early phase or indifferent types engage in chronic sleep debt. Fourth, a recent study facilitating ATUS data found that long workers (≥ 8 hours) terminated bed time on average 0.68 h earlier than short workers (< 8 hours) and 1.31 h earlier than respondents not working on the interview day, but time of going to bed did not differ among groups.3 Watching television was the primary activity people engaged in before going to bed, accounting for 46.3% of the 2h pre-bed. This shows, on the one hand, that television may be an important social Zeitgeber for the time of going to bed,11 and, on the other hand, that many long-workers may not be willing to pass on leisure time in order to increase sleep time. Finally, we have to acknowledge how little we know about chronic partial sleep loss, its consequences, and recovery from it. Despite the much higher prevalence of life-style induced chronic partial sleep deprivation, acute total sleep deprivation still dominates experimental reports and theoretical models of sleep-wake dynamics, even though we know that mathematical models of sleep homeostasis based on acute total sleep deprivation do not accurately predict the consequences of chronic partial sleep loss.12 If we are interested in the long-term effects of short sleep, epidemiological studies could give us the answers, and they have thus attracted more and more attention during the past few years. However, only a minority of these studies was prospective, sleep time was usually measured subjectively, the degree of adjustment for confounding varied greatly between studies, and, finally, it is unclear whether the reduced sleep times per se lead to higher risks of morbidity and mortality,5 or whether this is rather due to the associated changes in waking activity. Clearly more objective epidemiology is needed on sleep time and its associated health risks. Sleep is one of the basic human needs that both affects, and is affected by, numerous lifestyle, socioeconomic, and health related factors.13 Therefore, causality is likely to flow in both directions. Although we know that individual sleep need differs greatly between subjects, we presently have practically no ways of predicting who will respond to sleep loss.14 We expect to gain major insight from studies relating specific genotypes to the effects of sleep deprivation, but we have to acknowledge that these studies are still in the fledgling stages.15 All of the above point out important future research avenues. The manuscript by Knutson et al.6 reminds us, among other things, of the importance of consistent research methodologies in order to be able to make comparisons across studies and over time of sleep duration and its role in health and safety.

Auswirkungen des nächtlichen Bahnlärms auf den Schlaf - Ergebinisse einer Studie im Köln-Bonner Raum

Abstract: Im Rahmen der deutsch-franzosischen Kooperation in der Verkehrsforschung (DeuFrako), hat das DLR-Institut fur Luft- und Raumfahrtmedizin in einer 15-monatigen Feldstudie die Auswirkungen nachtlichen Bahnlarms auf den Schlaf untersucht (Teil des Projektes RAPS – Railway noise, Annoyance, Performance, Sleep). In dieser Studie wurden insgesamt 33 Probanden in je neun aufeinander folgenden Nachten polysomnographisch in ihrer hauslichen Umgebung untersucht. Zudem erfassten drei Klasse1 – Schallpegelmesser kontinuierlich die Schalldruckpegel LAS und LAF am Ohr des Schlafers und ausen an der Hausfassade vor dem Schlafraum. Jedes Gerausch, das den Hintergrundpegel L90 um mindestens 3 dB(A) uberschritt, wurde zudem aufgezeichnet. Sowohl die Metaanalyse fruherer Schlaflaborstudien am Deutschen Zentrum fur Luft- und Raumfahrt e.V. (DLR) und am Institut fur Arbeitsphysiologie in Dortmund (IfaDo) als auch die Auswertung dieser Feldstudie zeigen, dass die Aufwachwahrscheinlichkeiten durch Guterzuge, so wie sie derzeit im Rheintal eingesetzt werden, in Abhangigkeit von Maximalpegel und Pegelanstiegssteilheit hoher liegen als durch Flugzeuge, deren Auswirkungen auf den Schlaf in einer fruheren Feldstudie vom DLR untersucht wurden, und durch Strasenverkehr (der nur in den Laborstudien untersucht wurde). Im Gegensatz hierzu steht der uberwiegende Teil der Belastigungsstudien, der den Schienenverkehr als am wenigsten belastigend einstuft. Neben den Ergebnissen zum Schlaf werden ausfuhrlich die akustischen Auswertungen fur die Messorte und die psychologischen Wirkungen des nachtlichen Bahnlarms dargestellt.