As environmental hazards go, noise gets low billing. There is no Michael Pollan of sound; limiting your noise intake has none of the cachet of going paleo or doing a cleanse. When The New Yorker recently proposed noise pollution as the next public-health crisis, the internet scoffed. “Pollution pollution is the next big (and current) public health crisis,” chided one commenter. Noise is treated less as a health risk than an aesthetic nuisance—a cause for people who, in between rounds of golf and art openings, fuss over the leaf blowers outside their vacation homes. Complaining about noise elicits eye rolls. Nothing will get you labeled a crank faster.
Scientists have known for decades that noise—even at the seemingly innocuous volume of car traffic—is bad for us. “Calling noise a nuisance is like calling smog an inconvenience,” former U.S. Surgeon General William Stewart said in 1978. In the years since, numerous studies have only underscored his assertion that noise “must be considered a hazard to the health of people everywhere.” Say you’re trying to fall asleep. You may think you’ve tuned out the grumble of trucks downshifting outside, but your body has not: Your adrenal glands are pumping stress hormones, your blood pressure and heart rate are rising, your digestion is slowing down. Your brain continues to process sounds while you snooze, and your blood pressure spikes in response to clatter as low as 33 decibels—slightly louder than a purring cat.
Experts say your body does not adapt to noise. Large-scale studies show that if the din keeps up—over days, months, years—noise exposure increases your risk of high blood pressure, coronary heart disease, and heart attacks, as well as strokes, diabetes, dementia, and depression. Children suffer not only physically—18 months after a new airport opened in Munich, the blood pressure and stress-hormone levels of neighboring children soared—but also behaviorally and cognitively. A landmark study published in 1975 found that the reading scores of sixth graders whose classroom faced a clattering subway track lagged nearly a year behind those of students in quieter classrooms—a difference that disappeared once soundproofing materials were installed. Noise might also make us mean: A 1969 study suggested that test subjects exposed to noise, even the gentle fuzz of white noise, become more aggressive and more eager to zap fellow subjects with electric shocks.