Civilian exposure to chlorine gas: A systematic review

Introduction: Halogen pulmonary irritants (HPIs) are volatile liquids that directly damage the respiratory mucosa. Chlorine is readily available in large volumes as an industrial chemical and has a significant potential for accidental or deliberate release. We conducted a systematic review to determine the clinical features; treatment and long-term sequelae of civilian chlorine gas exposure. Methods: A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. Medline; Ovid and Google Scholar databases were searched from 1966 to January 2017. A database of relevant papers was compiled and descriptive statistics used to summarise the data. Results: Thirty-six papers describing 37 incidents involving 1566 individual acute exposers to chlorine gas were identified. The most common reported features were cough (29%), dyspnoea (22%), sore throat (16%), eye features (12%) and excessive sputum or haemoptysis (7%). Acute management included high-flow oxygen (32.8%); steroids (28.4%); bronchodilators (28.2%) and ventilation (2.3%). Nine deaths (0.6%) were reported. Follow-up data available in 60% of cases; full recovery was reported in 90% of cases where data was available. Discussion: Acute chlorine gas exposure in civilian incidents presented with acute respiratory features and irritation of the eyes and throat. The development of pulmonary oedema or ARDS was relatively rare when compared to military experience in the First World War.