Abstract
In 1987, workers in the kitchen of one of the teaching hospitals in Halifax, Nova Scotia began to experience symptoms of pruritus, folliculitis, wheezing, conjunctival irritation, sore throat and headache, all suggestive of an indoor air quality (IAQ) problem. Approximately 127 of 160 kitchen workers were affected over a 2-year period and the complaints included cognitive difficulties and reactivity to environmental irritants. Workers in other parts of the hospital developed increasingly serious problems, including bronchial hyperreactivity, nausea, diarrhoea, weight loss, hair loss, recurrent infections, myalgia and arthralgia as well as more sinister neurotoxic effects of memory loss, poor concentration, visual perceptual losses, peripheral paraesthesia, Raynaud's phenomenon, severe fatigue, dizziness and neuromuscular incoordination. Between 1991 and 1993, more than 700 workers, out of a total workforce of 1250, reported symptoms. Over 300 workers were off work for periods of from 3 months to 3 years and, at the time of writing, over 100 workers remain disabled and unable to work. During the course of this epidemic, it became clear that the clinical features did not readily fit into any widely accepted single disease category or syndrome. However, the ill health appeared to be related to IAQ problems in all buildings. It also became apparent that much of the symptomatology was similar to the condition known as multiple chemical sensitivity. The sick workers became intolerant of the hospital environment and their symptoms appeared to be precipitated by incitants such as chemicals, mould, dust, food, light or electromagnetic radiation. This state of ill health is described as environmentally induced dysfunction and the essential clinical features include chronic ill health for at least 3 months with evidence of dysfunction in multiple organ systems. The symptoms wax and wane, are provoked by exposure to certain environments (e.g. the workplace) and improve upon removal of triggers or irritants. Many of the workers improved when they stopped work and created a very clean environment at home. Most patients have cognitive impairment and evidence of autonomic nervous system dysfunction. Chemical sensitivity is an important part of this problem and recognition of the importance of this has to occur to allow research to take place and to assist in the treatment of those already afflicted and incapacitated by these problems. As a greater understanding is gained, it should be possible, in the future, to prevent problems of the same magnitude as reported here.