Abstract

OBJECTIVE--The admission to hospital of three construction workers with acute respiratory distress caused by inhalation of chlorine gas prompted the inspection of a building site located in a kraft pulpmill. The accidental emissions had taken place in the bleach plant and the construction workers assigned there were surveyed to uncover possible large scale health effects. DESIGN AND PARTICIPANTS--A questionnaire was presented to 281 workers (participation rate = 97%); 257 workers reported an average of 24 exposure episodes to chlorine and derivatives over a three to six month period. The air monitoring data available from the pulpmill's industrial hygienist were not useful in linking specific events reported by the workers to environmental conditions in the bleach plant. RESULTS--Over 60% of the workers described a characteristic flu like syndrome that lasted for an average of 11 days and was exacerbated by new bouts of exposure. Irritation of the throat (78%) and eyes (77%), cough (67%), and headache (63%) were the most often reported symptoms. Shortness of breath was reported by 54% of the participants and was not associated with age, smoking state, or history of asthma or chronic bronchitis. First aid self referral was associated with significantly greater reporting of most symptoms, including dyspnoea and cough. A significantly greater proportion of workers in the dyspnoea group had gone at least once for first aid care after a gassing incident (64% as opposed to 48%, p = 0.008). Throat irritation and cough persisted for mean intervals of eight and 11 days respectively. A flu like syndrome lasted for an average of 20 days. Seventy one subjects were considered to be a moderate to high risk of having persisting respiratory symptoms. CONCLUSION--Throat and eye irritation as well as cough and flu like symptoms are frequent occurrences after repeated accidental inhalation of chlorine. Subjects who consulted first aid care stations after a gassing incident are more likely to have persisting dyspnoea.