Document Type


Date of Degree

Summer 2018

Degree Name

MS (Master of Science)

Degree In

Occupational and Environmental Health

First Advisor

Anthony, T. Renee

First Committee Member

Nonnenmann, Matthew W.

Second Committee Member

O'Shaughnessy, Patrick T.


General noise regulations and guidelines protect workers against 8-hour time-weighted average noise exposures > 85-90 dBA that can cause health outcomes and noise induced hearing loss (NIHL), but the bus transportation industry has guidelines limiting lower noise exposures > 75-80 dBA to reduce safety hazards, including distraction and poor communication. These hazards can create dangerous driving conditions, especially for urban bus drivers, potentially causing a collision. Further research was necessary to characterize U.S. urban transit bus driver noise exposures to assess whether they exceeded 75, 80, 85, and 90 dBA, time-weighted, and to identify statistically significant noise exposure risk factors for this local transit system.

Time-weighted average noise exposures collected from the local transit system, a small urban bus system serving a university in Iowa City, showed the majority of drivers did not exceed 85 dBA due to short shift times, but these drivers may have been at a safety risk for distractions and poor communication due to loud environments > 75-80 dBA. The driver's AM/FM radio was a statistically significant risk factor (p = 0.004) affecting driver-shift TWA noise exposures. Projected noise exposure calculations showed that with bus driver shifts greater than or equal to 8 hours, the TWA noise exposures measured may exceed 85 dBA. Actual 8- hour time-weighted average noise exposures using sequential bus driver shifts did not exceed 90 dBA.


vii, 50 pages


Includes bibliographical references (pages 44-50).


Copyright © 2018 Austin Isamu Pierson