Hospital noise leads to higher work stress
Levels rarely rise to hearing hazard
With alarms sounding, helicopters landing, dishes clashing in a washer, compressors whirring, hospitals are noisy places.
Most of that noise will not rise to a hazardous level, but it’s still important for employee health professionals to assess noise levels and try to lower them, where possible, says Siobhan Dugan, MPH, PhD, health and safety consultant with Allina Employee Occupational Health at the Allina Health System in Minneapolis. Maintenance staff, in particular, may be exposed to noise levels that can harm their hearing due to working with compressors, generators, woodworking equipment, and motorized landscaping equipment. Dugan assesses noisy areas once a year and provides hearing conservation education for at-risk employees.
The U.S. Occupational Safety and Health Administration (OSHA) requires employers to monitor noise exposure and to identify affected workers if the noise is at or above 85 dB when averaged over eight hours. That length of exposure may be uncommon in health care, but peak levels can be high, Dugan says.
“It’s cheap to take care of this problem,” says Dugan. “It is debilitating and impairs the enjoyment of people’s older years [when hearing problems often worsen].”
Hearing loss isn’t the only impact from noise, notes Peter M. Rabinowitz, MD, MPH, assistant professor of medicine in the Yale Occupational and Environmental Medicine Program of the Yale University School of Medicine in New Haven, CT.
Noise can significantly add to work-related stress, he notes. And some types of noises may be particularly annoying, such as the high-pitched whine from an orthopedic bone saw.
“I think it’s a little bit of an overlooked issue in hospitals,” he says. “Hospitals are supposed to be quiet places, and they have become quite noisy places.”
One study of nurses in a pediatric intensive care unit found that nurses working in higher sound areas had higher heart rates and reported more stress and annoyance. While noise must be at 85 dB for a sustained period to damage hearing, the noise in this environment averaged 61 dB in the daytime and 59 dB at night.1 “The level of noise to increase stress level can be much lower than the noise necessary to hurt your hearing,” says Rabinowitz.
Here are some strategies to control noise in the hospital:
• Consider both the intensity and duration of noise.
One study of noise in an orthopedic practice found a level of 119.6 dB generated by the equipment. Three meters away, the sound level was 73 dB. The health care workers did not show any significant hearing loss at the end of a shift, perhaps because of intermittent exposure.2
It may be reassuring to health care workers who are exposed to occasional loud noises that even very loud noises of short duration may not be harmful, Dugan notes.
It’s still important to provide protection from very loud noise even if it is of short duration, she says. For example, Allina monitors the noise levels experienced by security staff who greet helicopters when they arrive to unload patients. The helicopters produce intense noise over 100 dB, but the duration is typically shorter than 20 minutes.
The health system requires employees to wear hearing protection, which basically are ear muffs with built-in communications devices, Dugan says.
• Consider noise levels when buying new equipment.
One Allina hospital asked for noise testing before selecting certain landscaping equipment. Dugan tested weed whackers and found one that had a high, annoying pitch but noted that it was no different in intensity.
Even so, she lauded that perspective. “I though that was forward thinking,” she says. “When you have a choice, include the safety screenings.”
Dugan also responds to concerns throughout the hospital to test the intensity of equipment. For example, based on staff requests, she tested vacuum cleaners (she didn’t find one in the hospital above 85 dB) and lab equipment (it was well below the limit).
• Reduce noise to lower stress on workers and patients.
Ironically, the sickest patients and the most stressed health care workers are subjected to the most noise — such as the alarms that sound in the intensive care unit or neonatal intensive care unit.
“Hospitals are places where people are supposed to get better. We should try to create an environment where that can happen easily. It means rest is very important,” says Les Blomberg, MA, director of the Noise Pollution Clearinghouse in Montpelier, VT.
For example, neonatal incubators have loud fans that could be quieted with insulation, says Blomberg.
A World Health Organization (WHO) report recommended a weighted average sound level of no more than 35 dB in treatment or observation areas and 30 dB in patient rooms.3 (The “A-weighting” of noise places greater emphasis on the more annoying, higher frequencies and mimics the impact on the human ear.)
“For most spaces in hospitals, the critical effects of noise are on sleep disturbance, annoyance, and communication interference, including interference with warning signals,” the WHO stated. “Particular attention should be given to the sound pressure levels in intensive care units and operating theatres. Sound inside incubators may result in health problems, including sleep disturbance, and may lead to hearing impairment in neonates.”
Sometimes, the noise level of alarms creeps up to levels that are unnecessarily high, Rabinowitz says. “The alarms need to be set to be louder than the background noise. The louder the background noise, the louder the alarms need to be. It’s like a vicious cycle,” he says.
• Educate employees about the importance of hearing conservation.
You may need to monitor the hearing annually of only a small number of employees who are exposed to high levels of noise. But many employees can benefit from education about hearing conservation.
Dugan offers a training session on hearing protection, describing the difference between muffs and different types of plugs, and explaining why and when they should be worn. She encourages employees to use the protection outside the workplace — for example, when hunting, at a loud concert, or using power tools at home.
Dugan also offers information on the signs of hearing loss, which may affect a greater number of workers as the work force ages.
“It’s an area where we know what to do, but we’re not doing enough of it,” she says of hearing conservation. “We have a lot of wasted hearing.”
References
1. Morrison WE, Haas EC, Shaffner DH, et al. Noise, stress, and annoyance in a pediatric intensive care unit. Crit Care Med 2003; 31:113-119.
2. Ullah R, Bailie N, Crowther S, et al. Noise exposure in orthopedic practice: potential health risk. J Laryngol Otol 2004; 118(6):413-416.
3. Berglund B, Lindvall T, Schwela DH, eds. Guidelines for Community Noise. Geneva: World Health Organization; 1999. Web site: www.who.int/docstore/peh/noise/guidelines2.html.
With alarms sounding, helicopters landing, dishes clashing in a washer, compressors whirring, hospitals are noisy places.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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