Night flight health risk to airport neighbours
Night-time noise from aircraft or traffic can increase a person's blood pressure even if it does not wake them, a survey of people living near to major airports has found
The study was carried out as part of a four-year project known as Hypertension and Exposure to Noise near Airports, or HYENA, which is exploring the health effects associated with exposure to aircraft noise. Work is under way near London's Heathrow airport, in parallel with research in Berlin, Athens, Milan and Amsterdam.
For the British leg of the project, scientists from Imperial College monitored volunteers in their homes, measuring their blood pressure remotely at 15-minute intervals and then analysing how this related to the noise recorded in their bedrooms.
The researchers found that volunteers' blood pressure increased noticeably after they experienced a noise louder than 35 decibels - such as aircraft travelling overhead, traffic passing outside or a partner snoring. This effect could be seen even if the volunteer remained asleep and so was not consciously disturbed.
Writing in the European Heart Journal, the scientists report that increase in blood pressure was related to the loudness of the noise. For example, for every 5dB increase in aircraft noise at its loudest point, there was an increase of 0.66 mmHg in systolic blood pressure. Aircraft caused an average increase in systolic blood pressure of 6.2 mmHg and an average increase in diastolic blood pressure of 7.4 mmHg.
However, the decibel level and not the origin of the sound appeared to be the key factor in determining the effect of a noise event and similar increases in blood pressure were seen also for other noise sources such as road traffic.
The research follows recent findings by the same researchers, showing that people who have been living near an international airport for at least five years, under a flight path, have a greater risk of developing high blood pressure than a population living in quieter areas.
That study, published in the journal 'Environmental Health Perspectives', showed that an increase in night-time aeroplane noise of 10dB increased the risk of high blood pressure by 14 per cent in both men and women.
Dr Lars Jarup of the Department of Epidemiology and Public Health at Imperial College is principal investigator for HYENA. He believes measures need to be taken to reduce noise levels from aircraft, in particular at night-time, in order to protect the health of people living near airports.
"We know that noise from air traffic can be a source of irritation, but our research shows that it can also be damaging for people's health, which is particularly significant in light of plans to expand international airports," said Jarup. "Our studies show that night-time aircraft noise can affect your blood pressure instantly and increase the risk of hypertension."
Image: Living under a flight path may increase your risk of hypertension