SURVEY OF CONSTRUCTION WORKERS REPEATEDLY EXPOSED TO CHLORINE OVER A 3 TO 6 MONTH PERIOD IN A PULPMILL .1. EXPOSURE AND SYMPTOMATOLOGY

Objective-The admission to hospital of three construction workers with acute respiratory distress caused by inhalation of chlorine gas promp ted the inspection of a building site located in a kraft pulp-mill. Th e accidental emissions had taken place in the bleach plant and the con struction workers assigned there were surveyed to uncover possible lar ge scale health effects. Design and participants-A questionnaire was p resented to 281 workers (participation rate = 97%); 257 workers report ed an average of 24 exposure episodes to chlorine and derivatives over a three to six month. period. The air monitoring data available from the pulp-mill's industrial hygienist were not useful in linking specif ic events reported by the workers to environmental conditions in the b leach plant. Results-Over 60% of the workers described a characteristi c flu like syndrome that lasted for an average of 11 days and was exac erbated by new bouts of exposure. Irritation of the throat (78%) and e yes (77%), cough (67%), and headache (63%) were the most often reporte d symptoms. Shortness of breath was reported by 54% of the participant s and was not associated with age, smoking state, or history of asthma or chronic First aid self referral was with significantly greater rep orting 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 4 8%, p = 0.008). Throat irritation and cough persisted for mean interva ls of eight and 11 days respectively. A flu like syndrome lasted for a n average of 20 days. Seventy one subjects were considered to be at mo derate to high risk of having persisting respiratory symptoms. Conclus ion-Throat and eye irritation as well as cough and flu like symptoms a re frequent occurrences after repeated accidental inhalation of chlori ne. Subjects who consulted first aid care stations after a gassing inc ident are more likely to have persisting dyspnoea.