Being subjected daily to the noise of aircraft flying overhead may be risk factor for high blood pressure, suggests research in Occupational and Environmental Medicine.
The researchers studied two groups of people aged between 19 and 80: 266 people living close to Stockholm Arlanda Airport; and almost 2700 inhabitants living in another part of greater Stockholm.
Each person was sent a questionnaire in 1997, covering aspects of lifestyle such as diet, exercise, and smoking, as well as length of residence and type of housing. Among various questions relating to health, respondents were asked if they had been diagnosed with high blood pressure within the previous five years.
Maximum and average aircraft noise on a typical day were assessed for each location, using validated environmental data and air traffic statistics. Residential areas were divided into five decibel bands: from 50 decibels upwards for average levels; and from 70 decibels occurring at least three times within 24 hours for maximum levels.
In areas subjected to average noise levels above 55 decibels or to maximum noise levels over 72 decibels, the prevalence of high blood pressure was 20 per cent compared with 14 per cent among those exposed to less noise. After adjusting for other factors likely to have an impact on the findings, people who lived in the highest noise zones were 80 per cent more likely to have high blood pressure. The greatest effects seemed to be in areas of low average but high maximum noise.
There was no difference in risk between men and women, but older people and those with good hearing were more likely to report high blood pressure if they lived in areas of high ambient aircraft noise levels.
The authors conclude that aircraft noise may act as a stressor, so raising blood pressure. Aircraft noise might also therefore be a risk factor for cardiovascular disease, they say.
An accompanying editorial warns that this type of study is notoriously difficult to do, but nevertheless concludes that there is some evidence suggesting a link between aircraft noise and high blood pressure.
[Increased prevalence of hypertension in a population exposed to aircraft noise 2001; 58: 769-73]
Journal
Occupational and Environmental Medicine