Airway response to chlorine inhalation (bleach) among cleaning workers with and without bronchial hyperresponsiveness

Abstract

Background: Symptoms of obstructive lung disease in domestic cleaning staff have been related to the use of bleach and other irritant cleaning products.

Material and methods: Included in the study were thirteen cleaning employees with work-related asthma-like symptoms, three asthmatic controls and three atopic subjects without bronchial hyperresponsiveness (BHR) who had no exposure to cleaning products. The study protocol consisted of a methacholine test, sputum induction and fraction of exhaled nitric oxide measurement (FENO) both at baseline and 24 hr after a 1-hr inhalation challenge with either placebo or bleach at a concentration of 0.4 ppm of chlorine.

Results: The inhalation of the placebo caused no bronchial reactions. Mean maximum fall in FEV(1) during challenge testing with bleach was significantly higher than the values obtained during the placebo challenge. Inhalation challenge with bleach elicited two isolated late asthmatic reactions and one dual asthmatic reaction. Of all the patients who underwent challenge testing with bleach, only one had a ≥2-fold decrease in methacholine PC(20) 24 hr after the challenge. No significant correlation was found between maximum fall in FEV(1) and PC(20) methacholine. Following challenge testing with bleach, no clinically significant changes in sputum cell counts or FENO were detected.

Conclusions: These results suggest that bleach inhalation at a concentration of 0.4 ppm-a concentration below 8-hr permissible occupational exposure level-brings about a substantial decrease in FEV1 in subjects with and without BHR. Some subjects have a positive challenge response to bleach inhalation.