Noise and Health Effects

One of my papers, penned for an Urban Environmental Health class taught by Patricia Hynes and Russ Lopez (great people), is posted at Science Metropolis. Science Metropolis is run by my friend Joe Caputo, a fellow BU grad student.

The paper focuses on noise in urban environments and addresses some of the main offenders: protesters and street preachers with megaphones, boom cars, motorycles, police, music clubs, etc. Here's the opening to the paper:

“America is the noisiest country that ever existed. One is waked up in the morning, not by the singing of the nightingale, but by the steam whistle. It is not surprising that the sound practical sense of the American does not reduce this intolerable noise.” - Oscar Wilde’s Impressions of America (1883)

America has evolved in noisier ways than Oscar Wilde could have ever imagined. In the place of the singing bird, one will hear car alarms, police sirens, motorcycles, jackhammers, and stereo systems as loud as jet planes. Urban settings, in particular, subject residents to potentially harmful levels of noise. Local governments are increasingly being pressured by city residents to either enforce existing noise ordinances or put new laws into effect that turn down the volume.

Normal conversations occur at a level of 50-70 decibels, but many sounds in our environment are far above that level. And the consequences can be dire. Prolonged exposure to sound above 85 decibels may cause permanent hearing loss. Motorcycles commonly eclipse 85 decibels (at 65 miles per hour, they surpass 110 decibels), while small firecrackers can reach 100-110 decibels. Ambulance and police sirens fall in the 110-120 decibel range, and if you have poor enough judgment to attend a rock concert, you could experience 140 decibels. These sounds are staples of the urban experience. Out of the 28 million Americans who have some degree of hearing loss, one-third damaged their hearing through excessive exposure to sound.

Noise and Health Effects

Exposure to noise can do much more than make you deaf. There is a growing body of literature indicating that noise exposure can induce hypertension and ischemic heart disease, annoyance, sleep disturbance, and decreased school performance. Traffic noise has been shown to cause considerable disturbance and annoyance in exposed subjects. Evidence linking noise to changes in the immune system and birth defects is more limited, however.

Children, as a group, could be more vulnerable to noise because of its ability to interfere with learning at a critical developmental stage and because children have “less capacity than adults do to anticipate, understand and cope with stressors.” A 2005 study of nearly 3200 children in Europe, aged 9-10, found that a chronic environmental stressor - like aircraft noise - could impair cognitive development in children, specifically reading comprehension.

It was tough to settle on specific decibel levels for the noise sources I described, but I went with the general consensus.

While the class focused on urban health, I also addressed some of the sources of noise in rural areas. F.e., wind turbines:

Even in rural areas, noise is a problem: residents in King City, Missouri, are complaining about the noise from wind turbines. Researchers are coining the phrase “wind turbine syndrome” to describe a collection of symptoms including headaches, anxiety attacks and high blood pressure. Researchers recommend that turbines be located at least a mile from homes, schools and hospitals.