Aircraft Noise and Kids Health, The
Munich Study
Facts Not Adequately Considered
in the County of Orange Environmental Impact Report for establishment of
a commercial airport at El Toro.
This summary was prepared from the
original report by a scientist member of the El Toro Airport Info Site
Team. For additional information, visit the web site on the Internet at
http://www.eltoroairport.org and e-mail inquiries to the site.
For many years it has been known that adverse environmental conditions affect human health. This study used measurable body functions to demonstrate how noise levels affect elementary school-aged-children.
The study concentrated on 135 third and fourth graders, living either in a high-noise-impact urban neighborhood, surrounding the Munich International Airport, or in a quiet urban neighborhood. The children from both neighborhoods were matched according to their socioeconomic status. The children were tested for two consecutive days, with a test time of 85 minutes each day.
The study focused on psychophysiological cognitive and motivational measures.
Psychophysiological measures included levels of stress hormones -- epinephrine (adrenaline) and norepinephrine, as well as blood pressure. The study showed that both epinephrine and norepinephrine were elevated among the children from the noisy communities. This same group also showed elevated systolic (higher value) blood pressure and lower reactivity systolic blood pressure. These results confirmed the link between chronic exposure to noise and elevation of stress hormones, elevation of resting blood pressure and differential cardiovascular reactivity. The last observation was interpreted by the authors as suggesting that chronic exposure to noise may deplete the coping capacity of the children; rendering them less able to mobilize fight or flight resources needed when faced with immediate dangers. Such deficiencies can directly affect cardiovascular diseases and indirectly affect the immune system.
Cognitive attributes were measured as follows:
Attention was measured by signal-to-noise. Each child listened to a favorite story at his/her preferred volume, with a background noise, including road, traffic and aircraft. At random intervals the storyteller's voice dropped by 10 dBA, and the child readjusted the volume of the story to his/her comfort level. The children from the noisy neighborhood chose a lower signal-to-noise ratio, indicating an accommodation to noisy distractions.
Memory was measured by the ability to recall, the next day, an interesting story read while intermittent bursts of noise were introduced during the reading. The children from the noisy neighborhood performed less accurately than those from the quieter communities.
Reading abilities were measured, using standardized reading tests. The children from noisy communities had larger numbers of errors, compared to the ones from the quieter neighborhoods.
Motivation was measured by the ability of children to solve two puzzles, after reading a text under noisy conditions. The first puzzle was insoluble, while the second one was soluble. The numbers of attempts made to solve the first puzzle before giving up and moving to the second one were recorded. The children from the noisy neighborhoods were less motivated, giving up sooner. The authors interpreted these observations as exhibiting less persistence in task performance when challenged.
Overall conclusions were that cognitive data indicate selective impairment in cognitive functioning among children from noisy communities. That in young children, more complex, higher order skills, such as reading, problem solving, and comprehension of difficult materials, appear vulnerable to adverse environmental conditions. Further, that children may cope with noise by developing cognitive strategies like tuning out noise, which may have consequences for language acquisition and speech processing.
Michael Bond, in the New Scientist, V152, Nov. 16,1996, added that while the authors were summarizing their findings, the old airport was closed, and another one was opened. The team concluded that the affected children recovered their deficiencies in memory and reading, two years after the closing of the airport. They also found that children living near the new airport are developing cognitive problems. One of the authors speculated that if the children were exposed to aircraft noise throughout the time they were growing up, the effects might be permanent.
Click here for "Kids Near Airports
Don't Read as Well", a new study from Cornell University researchers.