UCSF

Background: Firefighting is a hearing critical profession. Firefighters must be able to hear verbal and non-verbal auditory signals in hazardous and unpredictable environments. It is important to investigate factors that place a firefighter at risk of occupational injury, including personal, organizational, and environmental factors. The impact of hearing loss and/or tinnitus on occupational injury has not been researched among career firefighters in the United States.

Purpose: The aims of this dissertation are to: (1) identify the incidence of self-reported occupational injuries experienced by firefighters and their injury characteristics; (2) identify the prevalence of hearing loss (measured and perceived) and/or tinnitus reported by firefighters, and (3) evaluate the association between hearing loss and/or tinnitus and occupational injury among career firefighters.

Methods: A total of 249 firefighters from Central Texas and Northern California participated in a cross-sectional, internet-based survey. Occupational injury (within the past 12 months) and auditory function information was collected via self-report. Audiogram results were obtained from the firefighters' medical chart. Data collection included information about personal factors, organizational and environmental factors, and auditory function obtained through online self-report surveys.

Results: The literature review revealed that both hearing loss and hearing loss combined with tinnitus are associated with an increased risk for occupational injury among agricultural workers, blue-collar workers, older workers, and workers with disabilities. The first data-based study revealed that approximately 27% of firefighters reported an occupational injury within the past 12 months, and 4.4% experienced multiple injuries. The majority of injuries occurred on the scene of a non-fire call, while performing an activity that required lifting, pushing, and/or pulling. Firefighters who reported an occupational injury were more likely to be older and have a higher ratio of effort to reward imbalance (ERI), indicating higher levels of occupational stress experienced, compared to their co-workers who did not report an occupational injury. Injured firefighters were also more likely to report higher rates of overcommitment, fewer job rewards (money/salary), less esteem (respect and support), and fewer promotional prospects. The second data-based study concluded that increasing age and occupational stress was associated with an increased risk of occupational injury. High frequency hearing loss, tinnitus, self-reported ability to detect sound, and self-reported posture were not significantly associated with occupational injury. However, there was a significant interaction between ERI ratios and tinnitus; firefighters with both occupational stress and tinnitus were significantly more likely to report an occupational injury compared to their co-workers without tinnitus.

Conclusion: This dissertation study suggests that age, occupational stress, and tinnitus are risk factors for occupational injury among firefighters. Neither hearing loss nor tinnitus (alone) was a risk factor for occupational injury. Further research is warranted to explore the impact of occupational stress and tinnitus on occupational injuries among firefighters.