Study finds rates are 70 PER CENT higher in noisiest areas

Do YOU live under a flight path? You may be at risk of a heart attack: Study finds rates are 70 PER CENT higher in noisiest areas

  • New Jersey medics cross referenced heart attack data with noise pollution levels
  • Heart attack risk was 72% higher in areas with noise levels higher than 65 dB 
  • This meant noise pollution caused one in 20 of the state’s 16k heart attacks
  • Authors said noise pollution from transport can lead to stress and inflammation 

Not only is living under a noisy flight path or next to a busy road annoying, a study suggests it may increase your risk of a heart attack.

Scientists in New Jersey found the heart attack rate was 72 per cent higher in areas of the US state with the highest levels of noise pollution.

They estimate that one in 20 heart attacks could be attributed to traffic noise, which previous studies have suggested can disrupt sleep and cause chronic stress.

The study was presented at the American College of Cardiology’s Annual Scientific Session in Washington DC today. 

Lead author of the study Professor Abel Moreyra, a cardiologist at Rutgers Robert Wood Johnson Medical School, claimed noise pollution should be considered a risk factor for heart disease just like blood pressure and diet.

‘As cardiologists, we are used to thinking about many traditional risk factors such as smoking, hypertension or diabetes’ he said. 

‘This study and others suggest maybe we should start thinking about air pollution and noise pollution as additional risk factors for cardiovascular disease.’

A study from experts in New Jersey found the risk of having a heart attack was 72 per cent higher in areas of high noise pollution such as that caused by low flying aircraft

In the study researchers cross referenced heart attack admission data in the state in 2018 with government data on traffic noise for the same period, broken down by geographic areas.  

They divided around 16,000 heart attack patients by the average level of noise they were exposed to in a 24-hour period.

Examples of noise levels

10 decibels: Breathing. 

20 decibels: Whispers heard a metre away; light wind in trees. 

30 decibels: A low-voice conversation. 

40 decibels: A library, refrigerator, a quiet street at night. 

50 decibels: Moderate rain, washing machine. 

60 decibels: A normal conversation.

70 decibelsA busy street, vacuum cleaner. 

80 decibels: Alarm clock, factory, noisy restaurant. 

90 decibels: Subway, lawnmower, alarm.

100 decibels: A drill, chainsaw, motorcycle.

110 decibels: Loud concert, club. 

120 decibels: An emergency vehicle siren, airplane takeoff heard from about 300 metres.

130 decibelsA jackhammer, pneumatic tool. Human reaction: pain.

140 decibels:  An airplane takeoff heard from about 50 metres.

People exposed to an average noise level of 65 decibels or higher throughout the day were considered to be in a noise-polluted area.

This is equivalent to having someone constantly laughing in the same room as you the entire day and night.

The researchers found the heart attack rate was 72 per cent higher in noise polluted areas that breached the average daily decibel level.

These areas had 3,336 heart attacks per 100,000 people, compared with 1,938 per 100,000 people in the quieter areas.  

The study was observational, meaning it did not explore how noise pollution may lead to heart attacks. 

However, Professor Moreyra said it had previously been linked to stress, disturbances in sleep and emotional distress such as anxiety and depression, all of which could impact cardiovascular health.

Chronic stress in particular was linked to to inflammation of the blood vessels and subsequent risk of heart disease, he added. 

Professor Moreyra admitted that traffic pollution, which has a firmer link to heart problems, would have also played a role. 

Tiny airborne toxic particles can penetrate deep into the lungs causing a host of issues, including inflammation.   

Other limitations of the study included not accounting for noise levels people experienced at work, for example in construction, or other demographic, socioeconomic of the heart attack patients which may have influenced their risk. 

Professor Moreyra said future work could examine these areas to better identify the exact risk noise pollution posed to heart health. 

There are about 100,000 people are admitted to hospital after a heart attack each year in the UK, the equivalent of one admission every five minutes. 

The figure is much higher in the US with 850,000 heart attacks every year. 

An estimated 886,000 in England are estimated to be exposed to an average daily noise level in excess of 65 decibels according to a 2019 Department of Environment Food and Rural Affairs report.  

HOW NOISE POLLUTION AFFECTS HEALTH 

Noise can not only cause annoyance, but it can interfere with sleep, damage hearing and put people’s health at serious risk. 

The World Health Organisation recommends a guideline level of 30 dB LAeq for undisturbed sleep, and a daytime level for outdoor sound levels of 50dB to prevent people from becoming ‘moderately annoyed’.

Physiological effects of exposure to noise include constriction of blood vessels, tightening of muscles, increased heart rate and blood pressure and changes in stomach and abdomen movement.

A number of reports have made direct links between transport noise and cardiac health:

  • A study by Barts and the London School of Medicine in 2015, found that people surrounded by daytime traffic noise louder than 60db were 4 per cent more likely to die than those where noise levels were 55db – roughly the level of a loud conversation. 
  •  In the first study of its kind, researchers in Denmark in 2011 found that for every ten decibels more noise, the risk of a stroke increased by 14 per cent. The risk increased by 27 per cent for those aged 65 and over.
  •  Research published this year that tracked thousands of people living in Amsterdam over a four year period, found that being exposed to traffic noise over 70 decibels (db) were 65% more at risk of depression.

 The World Health Organization has calculated that at least 1m healthy life-years are lost every year in western European countries because of environmental noise. 

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