Upper airway irritation and small airways hyperreactivity due to exposure to potassium aluminium tetrafluoride flux: An extended case report

Abstract

Objectives - 22 workers, exposed to potassium aluminium tetrafluoride used as flux for soldering aluminium, were studied as clinical outpatients for symptoms of irritation of the nose, eye, skin, and airways. Methods - 16 volunteered for spirometry with methacholine provocation test including a test for small airways function by volume of trapped gas (VTG). Results - Median (range) latency time before respiratory symptoms developed was 6 (1-60) months. Symptoms of airways irritation diminished in all subjects after flux exposure ended. The FEV1 was within the normal range in 16 o£ 17 subjects before the methacholine provocation test. The FEV1 decreased by ≥ 20% in two out of 16 subjects after the 0.1% methacholine provocation. Four out of the 17 subjects had a high VTG before methacholine provocation. After inhalation of 0.1% methacholine eight out of 16 subjects (50%) had an abnormal increase of VTG indicating hyperreactivity in small airways. Discussion - Potassium aluminium tetrafluoride flux seems to induce an increase of bronchial reactivity in small airways. A setting of an occupational standard for potassium aluminium tetrafluoride is proposed.