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Journalism of Courage
In the beginning there was silence, and it was good. From silence came sound, not all of which was good. And the sound that was not welcome was called noise. And there got to be more and more of it.
A growing body of evidence confirms that the chronic din of jet traffic, construction crews and road projects, is taking a toll on our health and happiness. Providing scientific proof of this has not been easy 8212; in part because noise, defined as 8220;unwanted sound8221;, is to a large degree a matter of taste.
People pay good money to hear the same rock-and-roll that was used to torture the holed-up Panamanian dictator Manuel Noriega and induce cooperation from prisoners in Iraq and Guantanamo Bay.
But study after study has found that community noise is interrupting our sleep, interfering with our children8217;s learning, suppressing our immune systems and even increasing, albeit just a little, our chances of a heart attack. It is also reducing people8217;s inclination to help one another.
It is modern transportation, cars, motorcycles, trucks and air traffic, which accounts for most of the background noise that disturbs and even sickens people. A now-classic study conducted in the 1970s was among the first to indicate that such noise is more than an annoyance. It found that children living on the lower, noisier floors of an apartment building in Manhattan had lower reading scores than those living on higher floors.
But did noise explain the difference? After all, people tend to move away from extremely noisy neighborhoods if they can, and those who don8217;t are more likely to be poor, which by itself is a risk factor for delayed educational advancement and ill health.
To answer such questions, scientists took advantage of unusual situations in which people8217;s exposure to noise changed over time while other factors remained constant.
In a study of students attending an elementary school near noisy train tracks in New York, researchers showed that by the time the students reached sixth grade, those whose classrooms faced the train were a year behind those whose classrooms were on the quiet side of the building. After noise-reduction materials were installed in the classrooms and around the tracks, reading scores in the two groups equalised.
A 8220;natural8221; experiment in Germany helped clinch the case, when the old Munich airport was shut down and a new one opened at a distant site. Tests on third and fourth-graders before and after the switch showed that students near the old airport initially scored lower than others on memory and reading tests but improved after the airport closed. Their counterparts living near the new airport saw a decline in scores after the switch.
A chronic emergency
Noise that invades a classroom may make it hard for students to hear the teacher. But blood tests done on the Munich children helped reveal a more insidious biological mechanism through which noise wreaks much of its havoc. Children near the working airports had significantly higher levels of stress hormones adrenaline and cortisol.
These hormones help deal with sudden emergencies through the 8220;fight or flight8221; response. Blood pressure and heart rate go up in preparation for action. The blood becomes thick with oxygen-toting red blood cells. And the immune system gets suppressed as part of the shift toward fulfilling short-term needs. That response can be lifesaving in an attack, but it is counterproductive when activated chronically. Over the years it can literally corrode the body, eating away at blood vessels and other organs. 8220;This is the most disturbing thing about noise, because it means you are being exposed to this reaction all the time,8221; said Roberto Bertollini of the World Health Organization8217;s Special Programme on Health and Environment.
As a result of that hormonal activation, children near the working Munich airports had significantly higher blood pressure than children in quieter neighborhoods, adding to their risk of having a heart attack or stroke later.
Whether traffic noise increases the chances of heart disease or a heart attack has been harder to determine, because such studies require large numbers of people. But the evidence is growing.
A highly respected Dutch analysis combined the results from 43 studies that tracked chest pains, heart attacks and related problems with community noise. Using a statistical technique, it concluded that there is 8220;a slight increase in cardiovascular disease risk in populations exposed to air traffic and/or road traffic noise.8221;
Face the music
Even if chronic exposure to noise is unlikely to kill you, it can simmer under the surface and take a toll on your well-being.
Studies have shown that chronic night noise not only leaves you shrouded in a fog of fatigue, irritability and poor concentration, it also activates the stress response as you sleep. And while awakenings may decrease as you adjust to the din, the increased heart rate, blood pressure and breathing changes persist. 8220;The idea that people get used to noise is a myth,8221; the Environmental Protection Agency has reported. 8220;Even when we think we have become accustomed to noise, biological changes still take place inside us.8221;
The Health Council of the Netherlands found that high levels of mechanical noise, such as that from a hospital8217;s own air-conditioning equipment, can delay recovery in patients.
Another insidious effect of noise is its cultivation of what scientists call 8220;learned helplessness8221;. Children given puzzles in moderately noisy classrooms are not only more likely to fail to solve them but are also more likely to surrender early. The implications of learned helplessness on a child8217;s success in life are potentially pretty powerful.
Perhaps most disturbing in these times is that noise undermines generosity. In one study, people were found less likely to help someone pick up a bundle of dropped books when the noise of a lawn mower was present. Another showed that in a noisy environment, people playing a game were more likely to see their fellow players as disagreeable or threatening.
The Washington Post
