Respiratory dysfunction after potroom asthma.

Thirty-five men developed bronchial asthma while working in the potrooms in a primary aluminum production plant. Their asthma was diagnosed as work-related ("potroom asthma"). When examined 1-43 months after cessation of exposure (average follow-up period 2.5 yr), the group had an increased relative risk of morning cough (RR 1.7 CL95% 0.6-5.1), dyspnea on exertion (RR 2.8 CL95% 0.9-8.4), and wheezing (RR 6.1 CL95% 2.3-16.3) compared to controls from the same plant, in a 1:2 matched analysis. Matching criteria were age, smoking habits, and time of employment in the plant. The group means for FEV1 and MMEF were lower than for the controls, but the differences were not statistically significant. Ten of the 35 reported persisting asthma, dyspnea at night, or dyspnea on exertion. The study indicates an increased risk of respiratory dysfunction after potroom asthma. Medical follow-up after cessation of exposure is recommended.