SSS 2011-01-26（在线收听）

This is Scientific American's 60-Second Science. I'm Christopher Intagliata. Got a minute?

Living in the city, you can't escape traffic noise. But it's not just a nuisance. If you're over 65, the noise might be a risk to your health, too—by increasing your risk of a stroke. That's according to a study in the European Heart Journal.

The researchers studied over 51,000 Danish city dwellers for about a decade. And they mapped out noise levels at each person's home over time, using a noise calculating program. After accounting for other variables, like smoking history, diet and air pollution, they found that for the over-65 set, the risk of stroke rose 27 percent higher for every 10 decibels of noise exposure. The baseline was the volume of a normal conversation.

This study doesn't prove that road noise causes strokes. But previous studies have linked noise to heart attacks and higher blood pressure, too—possibly due to increased stress and sleep disturbance. For older people who already have trouble sleeping, the researchers say that extra tossing and turning could be the cause. So don't just worry about the fumes if you're relocating to a busy city street—keep in mind your sound health, too.

Thanks for the minute. For Scientific American's 60-Second Science, I'm Christopher Intagliata.