A Case Study to Demonstrate Noise and Ergonomic Issues in the Workplace

October is National Protect Your Hearing Month and National Ergonomics Month. 

Lacey is a veterinary technician who recently started working at a local veterinary clinic that cares for small pets. The clinic sees animals for routine visits but also provides specialty services like general surgery, dental care, grooming, and boarding services. Lacey loves working hands on with the animals but, lately, she’s experiencing some concerning symptoms.

One part of Lacey’s job is assisting the veterinarian with dental cleanings for dogs during early morning appointments. During the cleanings, Lacey sits at the procedure table and uses a hand scaler and ultrasonic scaler to clean the dogs’ teeth. Then she polishes the teeth with an electric tooth polisher. By the end of the cleanings, Lacey’s neck and back ache and she is relieved to stand up.

Sometimes a dog needs a tooth removed and the veterinarian takes over with an electric dental drill to help with removal. Depending on the size of the dog and location of the tooth, this can be a long process. Whenever there is a tooth removal, Lacey notices ringing in her ears afterward. She has tried different types of earplugs and eventually settled on using flat attenuation earplugs (also known as musicians’ earplugs) because she couldn’t understand instructions from the veterinarian when using the other kinds.

Lacey is always glad to walk around the clinic after cleanings and often assists the vet with routine appointments. Usually this means going from room to room pushing a laptop on a rolling cart. Lacey uses the laptop to enter patient information and helps with the exams. She is much shorter than the vet and often can’t find an adjustable chair to complete the animals’ charts. After the exams, Lacey helps schedule future appointments and updates charts.

Lacey ends her shifts helping her coworkers in the kennel. It can be hard to focus inside the kennel with nonstop barking, so she usually listens to music while cleaning cages and feeding the animals. The best part of her day is playing with the animals. Walking around helps her back pain and is a chance to clear her head. She usually plays countless games of fetch and tug-of-war with the dogs but, lately, the pain in her back, combined with some discomfort in her wrist, keep her from playtime. She worries she might miss out on her favorite activities if the pain gets any worse.

Stories like Lacey’s are all too common across multiple occupations.  We use her story to highlight some key points in recognition of National Protect Your Hearing Month and National Ergonomics Month.

Hearing Loss

• Hearing loss is one of the most common work-related illnesses [1].
• About 12% of U.S. workers have hearing difficulty [2].
• Among noise-exposed workers, 23% have hearing difficulty compared to 7% of non-noise-exposed workers [3].
• Twenty-four percent of worker hearing difficulty is due to occupational exposures including hazardous noise and ototoxic chemicals (chemicals causing damage to the auditory system) [4].
• Approximately 22 million workers (14%) are exposed to hazardous noise each year [2].
• About 10 million are exposed to solvents (ototoxic) [5], and an unknown number are exposed to other ototoxicants.

Hazardous levels of noise can happen in every industry and occupation.  However, noise-induced hearing loss can nearly always be prevented through noise reduction or use of hearing protection.  Hearing protection should be tailored for specific job needs.  When Lacey couldn’t understand the veterinarian, she needed to find earplugs that were appropriate for her exposure and communication needs.  Sometimes hearing protectors can provide more protection than necessary for the exposure. A common sign of over-protection is removing hearing protection to communicate. When the hearing protection is removed, it is obviously offering no protection.

Employers can take specific actions to protecting hearing in the workplace. Lacey’s employer should:

• Measure employees’ noise exposures to determine what hearing protection is required
• Consider installing noise absorbing materials where possible in the kennel area (e.g., washable acoustical tiles on the ceiling, rubber mats on the floor)
• Make sure that employees who use personal listening devices to cover up barking noise in the kennel are using sound-blocking earbuds so they do not turn the music up to a hazardous level
• Provide hearing protection appropriate for the noise levels in the workplace
• Train employees on proper use of hearing protection

Musculoskeletal Issues

• Musculoskeletal disorders (MSDs) continue to be a significant health problem in the workplace, affecting a rate of 27 per 10,000 full-time workers in 2020 [6].
• Overexertion injuries (sprains, strains, and tears) were the leading injury type involving days away from work and accounted for nearly 33% of cases in the private industry from 2018-2019 [7].
• Overexertion involving outside sources (material handling) ranked first among the leading causes of disabling injuries in 2019, accounting for $13.3 billion (23%) of the total workers’ compensation cost in the U.S. [8].
• Awkward postures and certain repetitive motions accounted for $4.7 billion and $1.7 billion of the total workers’ compensation cost, respectively [8].
• Low back pain was ranked the highest for leading cause of disability and years lived with disability out of 345 diseases and injuries in 2017 [9].
• Low back pain also leads to suffering and interference with quality of life for individuals [10,11].

Investigating workplace related factors for MSDs is a critical research area in the field of occupational health. Lacey experienced pain in her wrist, neck, and back following dental procedures. The dental procedure table is not height adjustable, allowing limited movement when seated. As a result, Lacey uses awkward postures, repeatedly bending her neck, contributing to her pain. During other appointments, Lacey uses the rolling laptop cart and can’t always access an adjustable chair. Even when she can’t sit at the correct height, she types on the laptop from the cart at an uncomfortable angle, leading to wrist pain.

Workplaces should use equipment and workstations that are ergonomically designed to minimize musculoskeletal disorders. In Lacey’s case, her employer should:

• Provide adjustable procedure tables and antifatigue mats near procedure tables
• Provide equipment to prevent awkward postures, like surgical loupes (eyeglasses with magnification) to reduce bending at the neck
• Educate employees on musculoskeletal disorders

Learn more about ergonomic interventions by industry.

Lacey’s case study is based on a Health Hazard Evaluation of employee noise exposures and ergonomic risks during dental procedures at a veterinary hospital. This October, take time to evaluate safety and health in your workplace, paying careful attention to noise and ergonomics issues.

For More Information:

• Ergonomics and Musculoskeletal Disorders – NIOSH
• Noise and Hearing Loss Prevention – NIOSH

Health Hazard Evaluations

• Health Hazard Evaluation Report 2018-0165-3374, Evaluation of Employee Noise Exposures and Ergonomic Risks During Dental Procedures at a Veterinary Hospital
• HHE Report No. HETA-2006-0212-3035, Kenton County Animal Shelter, Covington, Kentucky
• HHE Report No. HETA-2006-0196-3036, Liberty Veterinary Hospital, Liberty Township, Ohio

Emily Kirby, BPH, is a Health Communication Specialist in the NIOSH Office of Communication and Research to Practice.

References

1. Themann C, Suter A, Stephenson M [2013]. National Research Agenda for the Prevention of Occupational Hearing Loss—Part 1. Semin Hear 2013 34(03): 145-207. DOI: 10.1055/s-0033-1349351. https://www.cdc.gov/niosh/nioshtic-2/20043314.html.
2. Kerns E, Masterson E, Themann C, Calvert G [2018]. Cardiovascular conditions, hearing difficulty, and occupational noise exposure within US industries and occupations. Am J Ind Med. 61(6): 477-491. https://doi.org/10.1002/ajim.22833
3. Masterson E, Themann C, Luckhaupt S, Li J, Calvert G [2016]. Hearing difficulty and tinnitus among U.S. workers and non-workers in 2007. Am J Ind Med. 59(4): 290-300. https://doi.org/10.1002/ajim.22565
4. Tak S, Calvert G [2008]. Hearing Difficulty Attributable to Employment by Industry and Occupation: An Analysis of the National Health Interview Survey—United States, 1997 to 2003. J Occup Environ Med. 50 (1): 46-56. DOI: 10.1097/JOM.0b013e3181579316
5. NIOSH [1987]. Current Intelligence Bulletin 48 Organic Solvent Neurotoxicity. Cincinnati, OH:US DHHS, CDC, NIOSH, DHHS (NIOSH) publication No. 87-104, https://www.cdc.gov/niosh/docs/87-104/default.html.
6. Bureau of Labor Statistics [2022]. 2020 Nonfatal cases involving days away from work due to Musculoskeletal Disorders [One-Screen Data Search]. https://data.bls.gov/PDQWeb/cs
7. Bureau of Labor Statistics [2019]. Employer-reported workplace injuries and illnesses. News release, November 7, https://www.bls.gov/news.release/archives/osh_11072019.htm.
8. Liberty Mutual [2021] Workplace Safety Index, https://business.libertymutual.com/insights/2021-workplace-safety-index-the-top-10-causes-of-disabling-injuries/.
9. GBD [2018]. Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet 392(10159):1789-185. DOI: 10.1016/S0140-6736(18)32279-7.
10. Keeley P, Creed F, Tomenson B, Todd C, Borglin G, Dickens C [2008]. Psychosocial predictors of health-related quality of life and health service utilisation in people with chronic low back pain. Pain 135(1-2):142-150. DOI: 10.1016/j.pain.2007.05.015.
11. Husky MM, Ferdous Farin F, Compagnone P, Fermanian C, Kovess-Masfety V [2018]. Chronic back pain and its association with quality of life in a large French population survey. Health Qual Life Outcomes 16(1):19. DOI: 10.1186/s12955-018-1018-4