[Zinc chloride smoke pollution. Effects of minimal exposure]

Thirteen patients were exposed to accidental zinc chloride inhalation during an army exercise. Smoke bombs were released in open air. The exposure was modest ranging from "taking a few inhalations" to "5-10 minutes in a house with smoke drifting in through unshuttered windows". Initial symptoms were scanty. All patients received inhalation steroid on admittance followed by i.v. bolus of hydrocortisone. Four patients continued systemic steroid treatment (prednisolone 40 mg with stepwise reduction to zero over four weeks) because exposure was judged significant (> 1 minute of unprotected inhalation). No respiratory symptoms developed within an eight week observation period. However, a gradual decline in pulmonary CO diffusion capacity (to 85% (76-99 of initial capacity) was observed within the first four weeks. It is concluded that a very modest inhalation of zinc chloride smoke may induce prolonged impairment of pulmonary function.