Occupational hazards for school bus drivers
By Brianna Boyd, CHES, MPH (c), Derek G. Shendell, D.Env., MPH and Koshy Koshy, Ph.D.
School bus drivers play a vital role in safely transporting children to and from school each day, ensuring their well-being while navigating various conditions. According to the Bureau of Labor Statistics (BLS), school transportation services in the U.S. cover approximately 370,000 drivers and bus aides, 480,000 buses and 26 million student passengers.
This essential job comes with a set of occupational hazards that can adversely affect driver health and safety. From whole-body vibration (WBV) to exposure to diesel exhaust fumes and ergonomic issues, school bus drivers face unique challenges and potential long-term safety and health problems that must be addressed.
Whole body vibration: an unseen danger
One of the most significant, yet overlooked, occupational hazards for school bus drivers is whole- body vibration (WBV), the physical force transmitted to a driver’s body after prolonged exposure to vibrations from the vehicle. School buses are known to transmit significant vibrations through their seats and floorboards. Vehicle design and type of driver seat, including suspension and seat cushions, can affect exposure to WBV (Blood et al., 2010). Over time, these vibrations may lead to musculoskeletal disorders, chronic pain and discomfort.
According to the U.S. Centers for Disease Control and Prevention (CDC), studies have indicated that bus drivers exposed to WBV are at a heightened risk for developing back pain, leg fatigue and other musculoskeletal issues. In addition, prolonged exposure can contribute to chronic conditions such as herniated discs, sciatica and even compromised posture. Lumbar spine issues are frequently reported among drivers, with direct and indirect costs for employers and employees (Lewis et al, 2012).
A study aimed to determine levels of vibration exposure for bus drivers used applicable standards from the International Organization for Standardization (ISO) to identify if there were differences in vibration levels and seat transmissibility between different road types (Lewis et al., 2012). The study concluded that bus drivers are exposed to elevated daily vibration levels, especially on certain road types. When compared to a car, vibration exposure was nearly doubled. Bus seats amplified the vibration rather than attenuating it. Chronic exposure to WBV is of concern because it happens over extended periods, typically throughout the workday, which may exacerbate the cumulative effects on a driver’s body.
According to data from the BLS, from 2021 through 2022, there were 2,110 cases of school bus drivers sustaining injuries requiring days away from work. While WBV cannot be mitigated entirely, a multifaceted approach could significantly reduce risks of drivers experiencing WBV. Upgrade buses with improved suspension systems and seat modifications, such as shock-absorbing seats. Regular breaks and exercises promoting flexibility and strength may help reduce the risk of musculoskeletal injuries caused by prolonged exposure to vibration.
Exposure to diesel exhaust
Another significant hazard school bus drivers face is exposure to diesel exhaust fumes. Diesel engines, common in school buses, release multiple air pollutants. According to the U.S. Environmental Protection Agency (EPA), diesel exhaust is a mixture of gases and particles produced when diesel fuel is burned. This includes harmful substances including nitrogen oxides, particulate matter and carbon monoxide. These pollutants can accumulate in the bus cabin, especially during idling periods, which are common in school bus operations. The risks are even more significant when buses are not adequately ventilated or during extreme weather conditions when windows are closed.
Prolonged exposure has been linked to respiratory issues, including bronchitis and other pulmonary diseases. Inhaling diesel fumes, both particles and gases, not only presents immediate or acute effects, but long-term or chronic exposure can increase one’s risk of heart disease and lung cancer. In 1989, the International Agency for Research on Cancer identified exhaust emissions from diesel engines as a probable human carcinogen (Weir, 2002).
Diesel exhaust exposure can also be exacerbated during periods of idling. Previous research and agency guidance from the EPA highlighted how buses often remain idle for extended periods while waiting for students to embark or disembark. During idle times, the engine continues to emit harmful exhaust, which infiltrates the bus cabin. Drivers who spend long hours on the bus face a significantly higher risk for health complications due to prolonged exposure.
To reduce the harmful effects of diesel exhaust, bus fleets should consider investing in electric fleets or utilizing cleaner diesel fuels, such as soy-based biodiesel. Furthermore, idling policies should be enforced—limit idling of buses and cars, trucks, vans and other such vehicles—to help reduce the amount of potential diesel exhaust particles and gases or fumes entrained back into the cabin of the bus. In New Jersey, the idling of a vehicle is prohibited for more than three minutes.
However, there are two exceptions to the idling rule. Buses may idle for up to 15 minutes as passengers embark and disembark, and for up to 15 minutes when the bus has been stopped for three hours or more and if the temperature is lower than 25 degrees F.
According to the New Jersey Idling Fact Sheet, hundreds die prematurely in New Jersey from exposure to diesel exhaust. Thus, maintaining a proper ventilation system, installing air filters and using air purifiers inside buses can help to improve air quality.
Ergonomic risks: driver seating and posture
The nature of a school bus driver’s job requires prolonged sitting and repetitive motions, which can lead to significant ergonomic hazards. Poor seating design, inadequate lumbar support and improper driving posture can contribute to musculoskeletal problems. A stable driving posture requires the neck, back, shoulder and arm muscles to maintain static muscular tension over a sustained period, producing localized muscular fatigue aches and pains (Maduagwu et al., 2022).
School buses are often not ergonomically suited for adults. The inability to adjust the seat to a comfortable position can exacerbate these issues, leading to chronic pain and long-term injury. Furthermore, the repetitive act of steering and operating pedals can cause strain on the driver’s wrist and legs. Most school bus seats lack lumbar support, which is essential for maintaining proper spine alignment. Prolonged sitting in these seats can lead to slumping, poor posture and, eventually, back and neck pain.
To reduce ergonomic risks, bus fleets should consider investing in better-designed seats with adjustable lumbar support, seat height and backrest tilt to help alleviate discomfort. Additionally, buses should have controls to allow the bus driver to maintain a more neutral and comfortable position while driving. This should be coupled with training about the benefits of proper posture and ergonomic solutions to empower the drivers to feel more in charge of their health. Finally, drivers need adequate breaks to help break up prolonged sitting.
A multifaceted approach
School bus drivers play a crucial role in ensuring the safe transportation of children to and from school. However, this work comes with significant health and safety risks. Exposure to whole-body vibration (WBV), diesel exhaust and ergonomic hazards present real and long-term challenges for every driver’s well-being. These occupational hazards are often overlooked because they are the “unseen hazards,” yet they have serious implications. From chronic musculoskeletal pain to respiratory issues, these occupational hazards are real and detrimental to overall health.
Addressing concerns requires a multifaceted approach. Bus fleets should seek to invest in electric fleets or an environmentally friendlier form of diesel with particulate matter traps. Regular breaks and exercise should be encouraged and promoted to help reduce musculoskeletal disorders. By prioritizing the health and safety of school bus drivers, we assist in improving their quality of life, thus ensuring they can continue to perform their vital role.
Brianna Boyd is a certified health education specialist currently pursuing an MPH in Occupational Health and Safety at the Rutgers School of Public Health, where Dr. Derek Shendell is a professor and Dr. Koshy Koshy is an associate professor. They worked in coordination with the New Jersey Work Environment Council to produce this article.
What local associations can do
- Create a health and safety committee and recruit a bus driver to serve on it.
- Create a health and safety survey for bus drivers and review results with the health and safety committee.
- Educate bus drivers on the NJ anti-idling law (using the factsheet in resources list above).
References and resources
Occupational Medicine (Oxford, England)
“Whole-body vibration exposure in metropolitan bus”
by Lewis, C. A., and Johnson, P. W. (2012).
International Journal of Environmental Research and Public Health
Pickard, O., Burton, P., Yamada, H., Schram, B., Canetti, E. F. D., and Orr, R. (2022).
U.S. Environmental Protection Agency
“Diesel Exhaust and School Bus Idling” (June 2003)
New Jersey Department of Environmental Protection