A follow-up study of effects of chronic aircraft noise exposure on child stress responses and cognition.
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BACKGROUND: Children are a high-risk group vulnerable to the effects of chronic aircraft noise exposure. This study examines the effects of aircraft noise exposure on children's health and cognition around London Heathrow airport and tests sustained attention as an underlying mechanism of effects of noise on reading and examines the way children adapt to continued exposure to aircraft noise. METHODS: In this repeated measures epidemiological field study, the cognitive performance and health of 275 children aged 8-11 years attending four schools in high aircraft noise areas (16-h outdoor Leq > 66 dBA) was compared with children attending four matched control schools exposed to lower levels of aircraft noise (16-h outdoor Leq < 57 dBA). The children first examined at baseline were examined again after a period of one year at follow-up. Health questionnaires and cognitive tests were group administered to the children in the schools. RESULTS AND CONCLUSIONS: At follow-up chronic aircraft noise exposure was associated with higher levels of annoyance and perceived stress, poorer reading comprehension and sustained attention, measured by standardized scales after adjustment for age, social deprivation and main language spoken. These results do not support the sustained attention hypothesis previously used to account for the effects of noise on cognition in children. The reading and annoyance effects do not habituate over a one-year period and do not provide strong evidence of adaptation. (+info)
Increased prevalence of hypertension in a population exposed to aircraft noise.
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OBJECTIVES: To investigate whether there is a relation between residential exposure to aircraft noise and hypertension. METHODS: The study population comprised two random samples of subjects aged 19-80 years, one including 266 residents in the vicinity of Stockholm Arlanda airport, and another comprising 2693 inhabitants in other parts of Stockholm county. The subjects were classified according to the time weighted equal energy and maximum aircraft noise levels at their residence. A questionnaire provided information on individual characteristics including history of hypertension. RESULTS: The prevalence odds ratio for hypertension adjusted for age, sex, smoking, and education was 1.6 (95% confidence interval (95% CI) 1.0 to 2.5) among those with energy averaged aircraft noise levels exceeding 55 dBA, and 1.8 (95% CI 1.1 to 2.8) among those with maximum aircraft noise levels exceeding 72 dBA. An exposure-response relation was suggested for both exposure measures. The exposure to aircraft noise seemed particularly important for older subjects and for those not reporting impaired hearing ability. CONCLUSIONS: Community exposure to aircraft noise may be associated with hypertension. (+info)
Multilevel modelling of aircraft noise on performance tests in schools around Heathrow Airport London.
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STUDY OBJECTIVE: To examine the effects of chronic exposure to aircraft noise on children's school performance taking into account social class and school characteristics. DESIGN: This is a cross sectional study using the National Standardised Scores (SATs) in mathematics, science, and English (11 000 scores from children aged 11 years). The analyses used multilevel modelling to determine the effects of chronic aircraft noise exposure on childrens' school performance adjusting for demographic, socioeconomic and school factors in 123 primary schools around Heathrow Airport. Schools were assigned aircraft noise exposure level from the 1994 Civil Aviation Authority aircraft noise contour maps. SETTING: Primary schools. PARTICIPANTS: The sample were approximately 11 000 children in year 6 (approximately 11 years old) from 123 schools in the three boroughs surrounding Heathrow Airport. MAIN RESULTS: Chronic exposure to aircraft noise was significantly related to poorer reading and mathematics performance. After adjustment for the average socioeconomic status of the school intake (measured by percentage of pupils eligible for free school meals) these associations were no longer statistically significant. CONCLUSIONS: Chronic exposure to aircraft noise is associated with school performance in reading and mathematics in a dose-response function but this association is confounded by socioeconomic factors. (+info)
Noise control in the transportation corridor.
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This paper considers the opportunities for noise control within the route corridor required for construction of road, rail and other guided transport schemes. It deals with control of noise generation at source, and in the transmission path close to the point of generation. In this way it is possible to control the amount of acoustic power generated, and to absorb part of the radiated power at points of reflection. Purely reflective wayside barriers do little to absorb acoustic energy, merely reflecting it in a different direction. Whilst this has selfish benefits to the receptor in the shadow zone of the barrier, it makes things worse for others on the reflective side of the geometry. The paper therefore considers the options available to the engineer in the design of rolling and sliding interfaces and the use of acoustically absorptive finishes on all surfaces close to the point of noise generation. This includes the running surface itself, structural components, retaining walls, over and under passes, and the inner surfaces of track and wayside barriers. (+info)
The effects of chronic aircraft noise exposure on children's cognition and health: 3 field studies.
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This article provides a review of three of the most important field studies to have examined the non-auditory effects of chronic aircraft noise exposure on children's cognition and health. The design of each of the studies is outlined, relevant methodological issues are highlighted and the findings from the studies are reported. Effects are reported on annoyance and quality of life, motivation and helplessness, stress responses as indexed by neuroendocrine tests and blood pressure measurements. In terms of cognitive performance, effects are reported on reading, attention and long-term and working memory. (+info)
Respiratory and dermatological diseases in children with long-term exposure to road traffic immissions.
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The pathogenesis of allergies can be stimulated by adjuvant effects--i.e. air pollutants such as NO(2) and particles from diesel exhausts as well as noise--the latter especially during night-time. During sleep, noise signals which are associated with danger (i.e. lorry noise) have the potential to trigger stress reactions even if the noise level is low. Increases of cortisol in the first half of the night seem to play an important role. In a blind interview study, the combined effects of chronic exposure to traffic related air pollution and noise, upon the risk of skin and respiratory diseases in children were studied. All children between 5-12 years, who had consulted one of two participating paediatricians were included in the study. The paediatricians diagnoses of 400 children were analysed together with their parents answers regarding the density of road traffic on their street and several confounding factors. Multiple regression analyses resulted in relative risks of asthma, chronic bronchitis and neurodermitis, which increased significantly with increasing traffic load. A comparison with the literature on such effects caused by air pollution alone, showed that traffic noise during the night might have an adjuvant effect on the pathogenesis of the mentioned diseases. (+info)
Health status as a potential effect modifier of the relation between noise annoyance and incidence of ischaemic heart disease.
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AIMS: Traffic noise is a psychosocial stressor. Epidemiological studies suggest chronic noise stress to be a risk factor for cardiovascular disorders. METHODS: In a prospective cohort study, the association between annoyance and disturbances due to road traffic noise and the incidence of ischaemic heart disease (IHD) was studied in 3950 middle aged men. RESULTS: Depending on the questionnaire item, non-significant odds ratios for IHD incidence ranging from 0.9 to 1.4 were found for the highly noise annoyed/disturbed subjects when compared with the less annoyed/disturbed subjects, over the six year follow up period. However, this relation was strongly modified by the prevalence of pre-existing chronic diseases. In subjects free of any chronic disease at the beginning of the follow up, significant odds ratios between 1.7 and 3.0 were seen. In the subgroup with chronic diseases no such noise effects were seen. This surprising result of no effect in the group of people with a potential risk, due to pre-existing health problems, may be because of the dilution of the true effect due to recall bias. CONCLUSIONS: Annoyance and disturbance due to road traffic noise is associated with a higher incidence of IHD. Prevalence of disease can be an important effect modifier of the relation between noise annoyance and health outcomes. (+info)
A descriptive cross-sectional study of annoyance from low frequency noise installations in an urban environment.
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In order to improve the living conditions for respondents highly exposed to traffic noise, it has been recommended that one side of the building should face a "quiet side". Quiet may, however, be spoilt by noise from installations such as ventilation and air-conditioning systems. The noises generated by installations of this kind often have a dominant portion of low frequencies (20-200 Hz) and may be a source of great annoyance and sleep disturbance. This paper describes the cross-sectional part of an intended intervention study among residents exposed to traffic noise on one side of the building and to low frequency noise from installations on the other side of the building. A questionnaire masked as a general living environment study was delivered to a randomly selected person in each household. In total 41 respondents answered the questionnaire (71% response rate). Noise from installations was measured indoors in a bedroom facing the courtyard in a selection of apartments and outdoors in the yard. 24h traffic noise outdoor and indoor levels were calculated. The noise levels from installations were slightly above or at the Swedish recommendations for low frequency noise indoors with the window closed and exceeded the recommendations by about 10 dB SPL when the window was slightly opened. The proportion of persons who reported that they were very or extremely annoyed indoors from noise from installations was more than twice as high as for traffic noise. Installation noise also affected respondents' willingness to have their windows open and to sleep with an open window. The high disturbance of installation noises found in this study indicates the importance of also regulating the noise exposure on the "quiet side" of buildings. Further studies will give a better base for the extent of annoyance and acceptable levels of installation noises. (+info)