Changes in airway function and bronchial responsiveness after acute occupational exposure to chlorine leading to treatment in a first aid unit.

OBJECTIVES

To describe the baseline characteristics and the time course of changes in lung function in workers accidentally inhaling high concentrations of chlorine in a prospective study.

METHODS

Baseline spirometry and methacholine challenge test were performed in a cohort of 278 workers at risk of accidental inhalation of chlorine. Workers in whom accidental inhalation led to intervention in a first aid unit were reassessed five to 25 days after the accident and serially thereafter when there where notable changes.

RESULTS

During a four year follow up period, 13 workers were seen at the first aid unit after a symptomatic accidental inhalation. Three of them experienced notable functional changes: one worker experienced a 10% fall in forced expiratory volume in one second (FEV1), and the other two had a notable fall in the concentration of methacholine that caused a 20% fall in FEV1 (PC20). Two workers were smokers and one had a personal history of atopy. Baseline assessment was within the normal range in these three workers. Recovery was complete three months after the accidental inhalation.

CONCLUSION

Transient but notable decreases in airway function or increases in bronchial responsiveness can occur after an accidental inhalation of high concentrations of chlorine in workers at risk.