In 1982, asthma and allergy to laboratory animals among persons who worked with the animals gained increased recognition as an occupational health problem affecting researchers, veterinarians, technicians, animal handlers, and others. At that time, more than 90,000 workers across the United States were at risk due to their exposure to lab animals in the more than 1,100 facilities registered by the United States Department of Agriculture. Several surveys of exposed workers indicated a prevalence rate of allergic symptoms due to laboratory animal allergy ranging from 19-30 percent in animal workers. Asthma was also a frequent disease among animal workers; these surveys indicated that as many as 13-14 percent of exposed workers had asthma.