Gösta Bluhm

Hypertension and exposure to noise near airports: the HYENA study.

Background An increasing number of people are exposed to aircraft and road traffic noise. Hypertension is an important risk factor for cardiovascular disease, and even a small contribution in risk from environmental factors may have a major impact on public health. Objectives The HYENA (Hypertension and Exposure to Noise near Airports) study aimed to assess the relations between noise from aircraft or road traffic near airports and the risk of hypertension. Methods We measured blood pressure and collected data on health, socioeconomic, and lifestyle factors, including diet and physical activity, via questionnaire at home visits for 4,861 persons 45–70 years of age, who had lived at least 5 years near any of six major European airports. We assessed noise exposure using detailed models with a resolution of 1 dB (5 dB for United Kingdom road traffic noise), and a spatial resolution of 250 × 250 m for aircraft and 10 × 10 m for road traffic noise. Results We found significant exposure–response relationships between night-time aircraft as well as average daily road traffic noise exposure and risk of hypertension after adjustment for major confounders. For night-time aircraft noise, a 10-dB increase in exposure was associated with an odds ratio (OR) of 1.14 [95% confidence interval (CI), 1.01–1.29]. The exposure–response relationships were similar for road traffic noise and stronger for men with an OR of 1.54 (95% CI, 0.99–2.40) in the highest exposure category (> 65 dB; ptrend = 0.008). Conclusions Our results indicate excess risks of hypertension related to long-term noise exposure, primarily for night-time aircraft noise and daily average road traffic noise.

Road traffic noise and hypertension

Background: It has been suggested that noise exposure increases the risk of hypertension. Road traffic is the dominant source of community noise exposure. Objective: To study the association between exposure to residential road traffic noise and hypertension in an urban municipality. Methods: The study population comprised randomly selected subjects aged 19–80 years. A postal questionnaire provided information on individual characteristics, including diagnosis of hypertension. The response rate was 77%, resulting in a study population of 667 subjects. The outdoor equivalent traffic noise level (Leq 24 h) at the residence of each individual was determined using noise-dispersion models and manual noise assessments. The individual noise exposure was classified in units of 5 dB(A), from <45 dB(A) to >65 dB(A). Results: The odds ratio (OR) for hypertension adjusted for age, smoking, occupational status and house type was 1.38 (95% confidence interval (CI) 1.06 to 1.80) per 5 dB(A) increase in noise exposure. The association seemed stronger among women (OR 1.71; 95% CI 1.17 to 2.50) and among those who had lived at the address for >10 years (OR 1.93; 95% CI 1.29 to 2.83). Analyses of categorical exposure variables suggested an exposure–response relationship. The strongest association between exposure to traffic noise and hypertension was found among those with the least expected misclassification of true individual exposure, as indicated by not having triple-glazed windows, living in an old house and having the bedroom window facing a street (OR 2.47; 95% CI 1.38 to 4.43). Conclusion: The results of our study suggest an association between exposure to residential road traffic noise and hypertension.

Long-Term Exposure to Road Traffic Noise and Myocardial Infarction

Background: An association has been reported between long-term exposure to road traffic noise and the risk of myocardial infarction (MI), but the evidence is limited and inconclusive. No previous study has simultaneously analyzed the role of exposure to noise and air pollution from road traffic in the risk of MI. Methods: A population-based case-control study on MI was conducted 1992–1994 in Stockholm County. Participants answered a questionnaire and underwent a physical examination. Residential exposure to noise and air pollution from road traffic between 1970 and 1992–1994 was assessed for 3666 participants (1571 cases of MI and 2095 controls), based on residential history combined with information on traffic intensity and distance to nearby roads. Information was also obtained on factors potentially affecting the relationship between noise exposure and MI, such as noise annoyance. Results: The correlation between long-term individual exposure to noise and air pollution from traffic was high (r = 0.6). The adjusted odds ratio for MI associated with long-term road traffic noise exposure of 50 dBA or higher was 1.12 (95% confidence interval = 0.95–1.33). In a subsample, defined by excluding persons with hearing loss or exposure to noise from other sources, the corresponding odds ratio was 1.38 (1.11–1.71), with a positive exposure–response trend. No strong effect modification was apparent by sex or cardiovascular risk factors, including air pollution from road traffic. Conclusions: The results lend some support to the hypothesis that long-term exposure to road traffic noise increases the risk for MI.

Increased prevalence of hypertension in a population exposed to aircraft noise

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. Main messages Exposure to aircraft noise may be a risk factor for hypertension. It is suggested that special attention be paid to maximum noise levels because of possible physiological effects from aircraft noise.

Acute effects of night-time noise exposure on blood pressure in populations living near airports

AIMS Within the framework of the HYENA (hypertension and exposure to noise near airports) project we investigated the effect of short-term changes of transportation or indoor noise levels on blood pressure (BP) and heart rate (HR) during night-time sleep in 140 subjects living near four major European airports. METHODS AND RESULTS Non-invasive ambulatory BP measurements at 15 min intervals were performed. Noise was measured during the night sleeping period and recorded digitally for the identification of the source of a noise event. Exposure variables included equivalent noise level over 1 and 15 min and presence/absence of event (with LAmax > 35 dB) before each BP measurement. Random effects models for repeated measurements were applied. An increase in BP (6.2 mmHg (0.63-12) for systolic and 7.4 mmHg (3.1, 12) for diastolic) was observed over 15 min intervals in which an aircraft event occurred. A non-significant increase in HR was also observed (by 5.4 b.p.m.). Less consistent effects were observed on HR. When the actual maximum noise level of an event was assessed there were no systematic differences in the effects according to the noise source. CONCLUSION Effects of noise exposure on elevated subsequent BP measurements were clearly shown. The effect size of the noise level appears to be independent of the noise source.

Aircraft noise and incidence of hypertension.

Background: An association between aircraft noise exposure and hypertension prevalence has been suggested but there are no longitudinal studies of this association. Our aim was to investigate the influence of aircraft noise on the incidence of hypertension. Methods: A cohort of 2754 men in 4 municipalities around Stockholm Arlanda airport was followed between 1992–1994 and 2002–2004. The cohort was based on the Stockholm Diabetes Preventive Program; half of the study subjects had a family history of diabetes. Residential aircraft noise exposure (expressed as time-weighted equal energy and maximal noise levels) was assessed by geographical information systems techniques among those living near the airport. Incident cases of hypertension were identified by physical examinations, including blood pressure measurements, and questionnaires in which subjects reported treatment or diagnosis of hypertension and information on cardiovascular risk factors. Analyses were restricted to 2027 subjects who completed the follow-up examination, were not treated for hypertension, and had a blood pressure below 140/90 mm Hg at enrollment. Results: For subjects exposed to energy-averaged levels above 50 dB(A) the adjusted relative risk for hypertension was 1.19 (95% CI = 1.03–1.37). Maximum aircraft noise levels presented similar results, with a relative risk of 1.20 (1.03–1.40) for those exposed above 70 dB(A). Stronger associations were suggested among older subjects, those with a normal glucose tolerance, nonsmokers, and subjects not annoyed by noise from other sources. Conclusion: These findings suggest that long-term aircraft noise exposure may increase the risk for hypertension.

Saliva cortisol and exposure to aircraft noise in six European countries.

Background Several studies show an association between exposure to aircraft or road traffic noise and cardiovascular effects, which may be mediated by a noise-induced release of stress hormones. Objective Our objective was to assess saliva cortisol concentration in relation to exposure to aircraft noise. Method A multicenter cross-sectional study, HYENA (Hypertension and Exposure to Noise near Airports), comprising 4,861 persons was carried out in six European countries. In a subgroup of 439 study participants, selected to enhance the contrast in exposure to aircraft noise, saliva cortisol was assessed three times (morning, lunch, and evening) during 1 day. Results We observed an elevation of 6.07 nmol/L [95% confidence interval (CI), 2.32–9.81 nmol/L] in morning saliva cortisol level in women exposed to aircraft noise at an average 24-hr sound level (LAeq,24h) > 60 dB, compared with women exposed to LAeq,24h ≤ 50 dB, corresponding to an increase of 34%. Employment status appeared to modify the response. We found no association between noise exposure and saliva cortisol levels in men. Conclusions Our results suggest that exposure to aircraft noise increases morning saliva cortisol levels in women, which could be of relevance for noise-related cardiovascular effects.

Hypertension and Exposure to Noise near Airports (HYENA) - study design and noise exposure assessment

An increasing number of people live near airports with considerable noise and air pollution. The Hypertension and Exposure to Noise near Airports (HYENA) project aims to assess the impact of airport-related noise exposure on blood pressure (BP) and cardiovascular disease using a cross-sectional study design. We selected 6,000 persons (45–70 years of age) who had lived at least 5 years near one of six major European airports. We used modeled aircraft noise contours, aiming to maximize exposure contrast. Automated BP instruments are used to reduce observer error. We designed a standardized questionnaire to collect data on annoyance, noise disturbance, and major confounders. Cortisol in saliva was collected in a subsample of the study population (n = 500) stratified by noise exposure level. To investigate short-term noise effects on BP and possible effects on nighttime BP dipping, we measured 24-hr BP and assessed continuous night noise in another sub-sample (n = 200). To ensure comparability between countries, we used common noise models to assess individual noise exposure, with a resolution of 1 dB(A). Modifiers of individual exposure, such as the orientation of living and bedroom toward roads, window-opening habits, and sound insulation, were assessed by the questionnaire. For four airports, we estimated exposure to air pollution to explore modifying effects of air pollution on cardiovascular disease. The project assesses exposure to traffic-related air pollutants, primarily using data from another project funded by the European Union (APMoSPHERE, Air Pollution Modelling for Support to Policy on Health and Environmental Risks in Europe).

Annoyance due to aircraft noise has increased over the years—Results of the HYENA study

In the HYENA study (HYpertension and Exposure to Noise near Airports) noise annoyances due to aircraft and road traffic noise were assessed in subjects that lived in the vicinity of 6 major European airports using the 11-point ICBEN scale (International Commission on Biological Effects of Noise). A distinction was made between the annoyance during the day and during the night. L(den) and L(night) were considered as indicators of noise exposure. Pooled data analyses showed clear exposure-response relationships between the noise level and the noise annoyance for both exposures. The exposure-response curves for road noise were congruent with the EU standard curves used for predicting the number of highly noise annoyed subjects in European communities. Annoyance ratings due to aircraft noise, however, were higher than predicted by the EU standard curves. The data supports other findings suggesting that the peoples attitude towards aircraft noise has changed over the years, and that the EU standard curve for aircraft noise should be modified.

Infrasound and low frequency noise from wind turbines: exposure and health effects

Wind turbines emit low frequency noise (LFN) and large turbines generally generate more LFN than small turbines. The dominant source of LFN is the interaction between incoming turbulence and the blades. Measurements suggest that indoor levels of LFN in dwellings typically are within recommended guideline values, provided that the outdoor level does not exceed corresponding guidelines for facade exposure. Three cross-sectional questionnaire studies show that annoyance from wind turbine noise is related to the immission level, but several explanations other than low frequency noise are probable. A statistically significant association between noise levels and self-reported sleep disturbance was found in two of the three studies. It has been suggested that LFN from wind turbines causes other, and more serious, health problems, but empirical support for these claims is lacking.