Exposures to respirable, airborne Penicillium from a contaminated ventilation system: clinical, environmental and epidemiological aspects.

Two out of fourteen workers in a clerical office suffered bronchial problems. An investigation found gross contamination with Penicillium mould of forced-air heater-cooler units which had not been properly maintained. A 50 to 80 fold excess in the number of colony-forming units per cubic meter or air in the affected office compared with a control office were found. Persistent alveolitis was diagnosed in one worker, while the other suffered from asthma, exacerbated by the poor indoor air quality. When the units were cleaned and regularly maintained, the first worker nevertheless suffered occasional relapses, indicating the further research may be necessary.