Photokeratitis and UV-radiation burns associated with damaged metal halide lamps

Background: Damaged metal halide lamps are known to cause outbreaks of photokeratitis and UV-radiation burns among children and adults, which has prompted the Food and Drug Administration, Rockville, Md, to publish consumer recommendations to prevent such injuries. We investigated 3 outbreaks of photokeratitis and UV-radiation burns in gymnasiums associated with failure to heed these recommendations. Objective: To determine the cause of the outbreaks and promote interventions to prevent further injuries. Design and Setting: A cohort study of persons exposed to damaged metal halide lamps during the index outbreak in a community gymnasium and a descriptive epidemiologic study of 2 subsequently identified outbreaks in other gymnasiums. Participants: A total of 273 persons potentially exposed during events in 3 gymnasiums. Main Outcome Measure: Photokeratitis with onset within 12 hours of the event. The intensity of UV radiation was measured, and an occupational exposure standard applied. Results: Investigation of the index outbreak identified 18 (approximately 3%) persons who met our case definition for photokeratitis. The median incubation period was 7 hours, and health care visits were reported by 11 persons (61%). of the 18 patients, 17 (94%) were seated in the back of the gymnasium. Among 37 persons sitting in this high-risk area, the attack rate was 46%. Only 1 (9%) of 11 persons wearing glasses or contact lenses with UV-radiation protection in the high-risk area developed photokeratitis (relative risk, 0.15; P = .01). The safe occupational exposure limit in the high-risk area was 10 to 15 minutes, but exposures of 1 to 3 hours were reported. Prevention recommendations had not been instituted at any of the 3 facilities. Conclusions: Injuries from metal halide lamps are avoidable, but prevention recommendations may not be widely observed. All facilities using metal halide lamps in areas where children may be exposed should follow the Food and Drug Administration recommendations; amending the National Electric Code may be warranted.