The concerns of any parent tending to a child may proliferate when entering the dampness of a public bathroom: Avoid the radioactive puddles on the floor, they might urge; Please don’t peek underneath the stall doors, and for heaven’s sake, don’t touch anything — if you do, if you must, just make sure you wash your hands.
What isn’t included on this list of completely legitimate anxieties is that the gust pouring out of the hand dryers — that essential pit stop before you scurry out of the sticky hellhole — might pose a threat to a child’s hearing.
This is the valuable discovery made by Nora Keegan, a 13-year-old girl from Calgary who, for the past four years — since her fifth grade science fair — has been studying the effects noisy hand dryers could have on children’s hearing.
“I found that sometimes after I used the hand dryers, my ears would start ringing,” Nora told CTV News Calgary on Tuesday.
To figure out just what was going on, Nora did what any precocious kid would do: she investigated. Her research was recently published in the official journal of the Canadian Paediatric Society.
For more than a year, Nora and her family shuttled across Calgary, equipped with measuring tape, a ruler, and decibel meter. They stopped off at 44 locations that might be popular for kids — schools, libraries, malls, Tim Hortons — to get readings on how loud the hand dryers were in each bathroom.
Watch: It looks like restroom hand dryers are worse than we thought. Story continues below.
“We think it’s cool that she noticed how loud hand dryers were and decided to do something about them,” said David Keegan, Nora’s dad. “She was kind of unstoppable... It was cool to see how devoted she was to this practical science that affects kids.”
Part-way through, Nora’s findings were so jarring that her parents forced her to wear noise-cancelling headphones as she took more measurements, the New York Times reported.
Nora found that many of the hand dryers she tested were much louder than their manufacturers had claimed, with some ringing in at about 110 decibels.
If that doesn’t sound like much, it is — it’s about as loud as a steel mill, or a turbo-fan aircraft right at takeoff.
In Canada, toys capable of emitting sounds that rise above 100 decibels have already been banned by Health Canada under the Hazardous Products Act, since that level of noise, studies have found, is high enough to cause hearing loss in children.
Nora found that hand dryer manufacturers were not accounting for the height of kids, the New York Times reported. Mostly, they were testing the sound levels for someone whose ears were about 18 inches away from the wall — much farther than that of a child, whose head would be much closer to the mouth of the contraption.
Children have much smaller ears, so sounds are much louder to them, but there are studies that suggest a number of ways to protect a child’s ear health.
A recent study in The Hearing Journal found one way to ensure children learn to protect their hearing is to teach them “to respect and appreciate it.” It isn’t a bad idea, the study suggests, to think about time limits for loud sounds. Adults and kids alike should adhere to a 80/90 rule, keeping their device volume below 80 per cent and limiting their daily listening time to 90 minutes or less.
It also suggests parents pay closer attention to headphone choices — noise-isolating earphones can reduce background noise — and that they try to select age-appropriate hearing protection for kids.
When it comes to hand dryers, though, the best option might be to go with the paper towel or the air-drying route.
Nora is hopeful that manufacturers use her findings to make better decisions — a dream most 13-year-olds, preoccupied with whatever most 13-year-olds are normally preoccupied by, could not even fathom.