If people who live in cities worry about anything it’s usually air pollution. But what about noise pollution? While studies have linked noise pollution to hypertension there was limited evidence that noise is linked to actual mortality. Until now.
The study measured daytime and nighttime traffic noise across the city of London. The researchers then compared the noise data to hospital admissions and mortality rates for 8.6 million residents.
The researchers found that median exposure to daytime traffic noise was 55 dB Traffic noise of greater than 60 dB was associated with a 5% increase in hospital admission for stroke in adults and a 9% increase in the elderly (75 or older). Daytime noise was also associated with a 4% increase in all-cause mortality. The results stood after adjusting for age, sex, area-level socioeconomic deprivation, ethnicity, smoking, air pollution, and neighborhood spatial structure.
Why does noise matter? Here’s what the researchers had to say:
Exposure to noise may affect the autonomic nervous system increasing heart rate, blood pressure, and concentrations of noradrenaline, a stress hormone. Noise can also affect the hypothalamus–pituitary–adrenal axis leading to increased levels of cortisol, another stress hormone. In the long term, these reactions are suggested to promote low-grade inflammation and cardiovascular morbidity. Another suggested pathway is via sleep disorders some of which have been linked to an increased risk of mortality.
Noise can have a modest, but noteworthy impact on your health. So next time you’re looking to move, aim for quieter parts of town. Also, another study found that it wasn’t so much noise level, as the difference in peak dB from the baseline noise level. So using a fan, white noise or earplugs could lessen the harmful impact.
Halonen, Jaana I., et al. “Road traffic noise is associated with increased cardiovascular morbidity and mortality and all-cause mortality in London.”European heart journal (2015): ehv216.
Stanchina, Michael L., et al. “The influence of white noise on sleep in subjects exposed to ICU noise.” Sleep medicine6.5 (2005): 423-428.