Health hazard evaluation report: HETA-2006-0212-3035, Kenton County Animal Shelter, Covington, Kentucky.
On April 13, 2006, the National Institute for Occupational Safety and Health (NIOSH) received a management request for a health hazard evaluation (HHE) from the Kenton County Animal Shelter (KCAS) in Covington, Kentucky. The HHE request asked NIOSH to assess the noise levels experienced by the animal shelter workers from barking dogs. On April 18 and 19, 2006, NIOSH investigators measured noise exposure levels for animal shelter workers. NIOSH investigators returned to the facility on October 12, 2006, to conduct hearing tests for all animal shelter workers. Nine animal shelter workers contributed 18 full-shift personal dosimetry measures over 2 days. Hearing tests were performed on 10 workers. Six of the 18 (33%) of the personal noise dosimetry measures exceeded the NIOSH recommended exposure limit. The Occupational Safety and Health Administration (OSHA) action level and the OSHA permissible exposure limit were not exceeded. Exposures were highest for workers who cleaned the dog kennels in the morning. Exposures were lower for employees who rotated between cleaning cat cages, providing food to the animals, and staffing the front desk. Four of the 10 workers tested showed some degree of hearing loss. Five employees with normal hearing showed "notches" (frequency at which there is a dip in the audiogram followed by an increase) at 4000 Hertz (Hz) and 6000 Hz in one or both ears. Notches occurring between 3000 to 6000 Hz may be indicative of the early stages of noise-induced hearing loss (NIHL). In addition, one employee with hearing loss had notches at 2000 Hz, 4000 Hz, and 6000 Hz. The notch at 2000 Hz is not consistent with NIHL. Some of the animal shelter workers at KCAS are exposed to excessive noise levels. Some of the workers have some hearing loss but it is not possible to assess whether it is related to noise exposure at the kennel. Recommendations are provided to reduce noise exposures and prevent further hearing loss. These recommendations include establishing a hearing loss prevention program, installing sound-absorbing materials in kennels, and wearing hearing protection devices when entering the kennel area.