Am. J. Respir. Crit. Care Med., Vol 150, No. 6, Dec 1994, 1714-1717.
Aluminium potroom asthma confirmed by monitoring of forced expiratory volume in one second
A Desjardins, JP Bergeron, H Ghezzo, A Cartier and JL Malo
Department of Chest Medicine, Hopital du Sacre-Coeur, Quebec, Canada.
Chronic airflow obstruction has long been seen among aluminium potroom
workers. Currently referred to as "potroom asthma," it is debatable as to
whether it is occupational asthma or nonspecific airway obstruction. A
35-yr-old male lifelong nonsmoker, with no history of asthma or atopy, was
hired by an aluminium plant that had begun its operation in 1986.
Preemployment screening, consisting of spirometry and a chest radiograph,
was normal. During his 12-h shifts, he replaced 10 to 20 anodes (prebake
type), spending 5 min each time close to open pots releasing hot fumes. The
patient experienced episodes of cough and dyspnea, which were resolved
during withdrawal from work in January and December 1991. He resumed work
in the potrooms in March 1992, his dyspnea recurred at work and at night
with 25% drops in peak expiratory flow rates (PEFR), associated with
mild-to-moderate bronchial hyperresponsiveness (PC20 histamine, 1.0 mg/ml).
After a chest physician's assessment, he was withdrawn from the potroom
department. Assessment of the bronchial response to the occupational
exposure in potrooms carried out in November 1992 revealed a pattern of
dual asthmatic response, paralleled by a drop in PC20 methacholine from 5.1
to 0.7 mg/ml. A similar pattern was seen again during repeat workplace
challenges 3 wk later. Spirometry obtained on control days was stable. We
conclude that asthmatic reactions can exist among workers in aluminium
smelters.
