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 of 17 subjects before the methacholine provocation test. The FEV1 decreased by > or = 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.