An epidemic of psychogenic illness in an electronics plant

We investigated an outbreak of illness in electronics plant workers. Questionnaire data revealed that 98 employees experienced symptoms, including light- headedness , headache, sleepiness, and numbness/tingling of the face or extremities. Attack rates by work station followed no apparent pattern. Extensive medical and environmental evaluation, including air sampling for numerous solvents and gases, provided no physical or chemical explanation for the epidemic. Compared with well employees, ill employees were more commonly female, complained more frequently of bothersome odors, and believed that greater danger existed of the illness recurring. Blood gas analyses of seven of 11 ill workers showed respiratory alkalosis, consistent with hyperventilation. The poorly defined nature of this illness, the absence of exposures to environmental contaminants in concentrations exceeding recommended limits, and the evidence of hyperventilation suggest that this outbreak was an incident of industrial psychogenic illness.