The sound of an airplane flying overhead at night may be the last thing you hear, while the study finds that noise can trigger a heart attack in two hours.
- Experts studied 24,886 deaths from cardiovascular disease between 2000 and 2015
- All the cases the team considered were located in the vicinity of Zurich Airport
- They analyzed the deaths compared to the night noise pollution of the aircraft
- Those exposed to noise of 40-50 decibels had a third higher risk of heart failure
Living under a crowded airway could have disadvantages beyond declining property values - it could increase the risk of dying from a heart attack, experts warned.
Researchers in Switzerland analyzed thousands of deaths from cardiovascular disease in the area around Zurich airport between 2000 and 2015.
They found that people exposed to night-time noises of the order of 40-50 decibels – similar to the thrombus of a refrigerator – were one-third more likely to have heart failure.
For those susceptible, the effect of planes flying overhead – as well as episodes of intense emotion – can lead to death in just two hours, the researchers said.
Living under a crowded flight path could have disadvantages beyond the decline in property value – it could also increase the risk of dying from a heart attack, experts warned
“We found that aircraft noise contributed to about 800 of the 25,000 cardiovascular deaths that occurred between 2000 and 2015 near Zurich airport,” said epidemiologist Martin Röösli of the Swiss Institute of Tropical and Public Health.
This represents 3% of the total cardiovascular deaths observed.
Previous research has found that noise pollution is responsible for approximately 48,000 cases of ischemic (or coronary) heart disease each year in Europe.
In their study, Dr. Röösli and colleagues analyzed data on 24,886 deaths from cardiovascular disease that occurred in the vicinity of Zurich airport between 2000 and 2015.
They used a so-called “case-crossover” model to determine whether the subject’s noise exposure around the time of death was unusually high compared to the sound levels they experienced at other randomly selected times.
To do this, the model combined a recording of all aircraft movements in and out of Zurich Airport during the 15-year study period with pre-existing calculations of noise exposure from different aircraft, traveling on given routes at different times.
“This study project is very useful to study the acute effects of noise exposure, with high daily variability – such as aircraft noise, given changing weather conditions or flight delays,” said the author and epidemiologist. Apolline Saucy.
“With this temporal analysis approach, we can isolate the effect of unusually high or low noise levels on the mortality of other factors.”
“Lifestyle characteristics such as smoking or diet cannot be a prejudice in this study project,” she added.
The team model suggested that the risk of cardiovascular death increases by 33% for people exposed to night noise in the order of 40-50 decibels – equivalent to the sound of a refrigerator in operation.
People exposed to night noise over 55 decibels – close to the normal conversation volume – had a 44% increase in the risk of cardiovascular death.
For comparison, being subjected to noises above 85 decibels – such as hair dryers, blenders and power tools – continuously for more than 30 minutes can lead to permanent hearing loss.
The results are similar to the effects that emotions, such as anger or arousal, have on cardiovascular mortality, Dr. Röösli noted.
“The associations were more pronounced for [women,] for people living in low-noise areas on the railway – and in buildings built before 1970. ”
In these cases, the subjects probably had less insulation to protect them from all the sounds – or less background noise to acclimatize to – leaving them more vulnerable to the sound of aircraft passing overhead, the researchers said.
Many airports – including Zurich, as well as London Gatwick and Heathrow – implement a flight curfew to reduce aircraft-related noise pollution between 11:30 pm and 6:00 am the next morning.
“Based on the results of our study, we can deduce that this night flight ban prevents further cardiovascular death,” concluded Dr. Röösli..
The full results of the study were published in the European Heart Journal.