A cluster of acoustic neuromas in fish hatchery workers

The National Institute for Occupational Safety and Health (NIOSH) received a request from the United States Fish and Wildlife Service (FWS) to determine if there is a relationship between acoustic neuroma and fish hatchery work. The request was triggered by a report from an FWS employee who suspected the possibility of such an association. Investigators used data provided by the personnel office of the FWS to calculate the incidence of acoustic neuroma among fish hatchery workers, and then to compare it with national rates. Four confirmed cases of acoustic neuroma were found among former fish hatchery workers. The overall incidence was estimated to be 15.41 per 100,000 person-years. This rate is more than 15 times higher than the rate among the general population. Even so, the small number of cases, as well as other factors, preclude the NIOSH from concluding that there is a definite cause-and-effect relationship. Further study is warranted.