Health: Sounds from planes flying overhead at night can cause a heart attack

Living under a busy flight path can have drawbacks beyond lowering the value of your property – it can increase your risk of death from a heart attack, experts have warned.

Researchers from Switzerland analyzed thousands of deaths from cardiovascular disease in the area around Zurich airport between 2000 and 2015.

They found that people exposed to nighttime noises on the order of 40-50 decibels – comparable to the thumping of a refrigerator – were one third more likely to have heart failure.

For those who are susceptible, the effect of planes flying overhead – like episodes of intense emotion – can lead to death within just two hours, the researchers said.

“We found that aircraft noise contributed to about 800 of the 25,000 cardiovascular disease deaths that occurred near Zurich Airport between 2000 and 2015,” said epidemiologist Martin Röösli of the Swiss Institute of Tropical and Public Health.

“This represents three percent of all observed cardiovascular deaths.”

Previous research has shown that noise pollution is responsible for approximately 48,000 cases of ischemic (or coronary) heart disease across Europe every year.

In their study, Dr. Röösli and colleagues analyzed data on 24,886 deaths from cardiovascular disease in the Zurich airport area during the period 2000–2015.

They used a so-called ‘case-crossover’ model to determine if the subject’s noise exposure around the time of death was unusually high compared to the noise levels they experienced at other randomly selected times.

To do this, the model combined a record of all aircraft movements in and out of Zurich airport during the 15-year study period with pre-existing calculations of the noise exposure of different aircraft traveling on certain routes at different times.

“This research design is very useful to study acute effects of noise exposure with high daily variability – such as aircraft noise, given changing weather conditions or flight delays,” said author and epidemiologist Apolline Saucy.

‘With this temporal analysis we can isolate the effect of unusually high or low noise levels on mortality from other factors.’

“Lifestyle characteristics such as smoking or diet should not be biased in this study design,” she added.

The team’s model suggested that the risk of cardiovascular death increases by 33 percent for individuals exposed to nighttime noise on the order of 40-50 decibels – equivalent to the noise of a working refrigerator.

People exposed to nighttime noise greater than 55 decibels – almost the volume of a normal conversation – had a 44 percent increase in their risk of cardiovascular death.

In comparison, exposure to sounds greater than 85 decibels – such as hairdryers, blenders, and power tools – continuously for more than 30 minutes can lead to permanent hearing loss.

“The results are similar to the effects emotions such as anger or excitement have on cardiovascular mortality,” noted Dr. Röösli.

Associations were more outspoken in favor [women,] for people who live in areas with little background noise from roads and railways – and in buildings built before 1970. ‘

In these cases, the subjects likely either had less insulation to protect them from all sounds – or less background noise to acclimate to – making them more vulnerable to the sound of planes flying overhead, the researchers said.

Many airports – including Zurich, as well as London Gatwick and Heathrow – have a curfew to reduce aircraft-related noise nuisance between 11.30pm and 6am the following morning.

“Based on our study results, we can conclude that this nocturnal flight ban prevents additional cardiovascular deaths,” concluded Dr. Röösli..

The full findings of the study are published in the European Heart Journal.