title: Survey of construction workers repeatedly exposed to chlorine over a three to six month period in a pulpmill: II. Follow up of affected workers by questionnaire, spirometry, and assessment of bronchial responsiveness 18 to 24 months after exposure ended.
abstract: OBJECTIVE
  The aim was to determine the prevalence of persistent respiratory symptoms and bronchial hyper-responsiveness due to reactive airways dysfunction syndrome in a population of construction workers at moderate to high risk of developing the syndrome, at an interval of 18 to 24 months after multiple exposures to chlorine gas during renovations to a pulp and paper mill.
  
  
  METHODS
  71 of 289 exposed workers (25%) were identified on the basis of an exposure and the onset of respiratory symptoms shortly after this event (moderate to high risk). A standardised respiratory questionnaire was first presented, followed by spirometry and a methacholine inhalation test on those whose questionnaire suggested the persistence of respiratory symptoms.
  
  
  RESULTS
  64 of 71 (90%) subjects completed the respiratory questionnaire at the time of the follow up. The questionnaire suggested a persistence of respiratory symptoms in 58 of the 64 workers (91%). Of the 58 subjects, 51 underwent spirometry and assessment of bronchial responsiveness. All of them used bronchodilators as required (not regularly) and four required inhaled anti-inflammatory preparations. Sixteen had bronchial obstruction (forced expiratory volume in one second) (FEV1 < 80% predicted) and 29 showed significant bronchial hyper-responsiveness.
  
  
  CONCLUSIONS
  Of the subjects (n = 71) who were at moderate to high risk of developing reactive airways dysfunction syndrome after being exposed to chlorine and were seen 18 to 24 months after exposure ended, 58 (82%) still had respiratory symptoms, 16 (23%) had evidence of bronchial obstruction, and 29 (41%) had bronchial hyper-responsiveness.
authors.affiliation: Outaouais Community Health Department (DSC), Hull, Quebec, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Bhérer
authors.forename: R
authors.initials: R
authors.lastname: Cushman
authors.forename: J P
authors.initials: JP
authors.lastname: Courteau
authors.forename: M
authors.initials: M
authors.lastname: Quévillon
authors.forename: G
authors.initials: G
authors.lastname: Côté
authors.forename: J
authors.initials: J
authors.lastname: Bourbeau
authors.forename: J
authors.initials: J
authors.lastname: L'Archevêque
authors.forename: A
authors.initials: A
authors.lastname: Cartier
authors.forename: J L
authors.initials: JL
authors.lastname: Malo
mesh_terms: D000328:Adult; D000402:Airway Obstruction / Q000139:chemically induced / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000139:chemically induced* / Q000503:physiopathology; D002713:Chlorine / Q000506:poisoning*; D002908:Chronic Disease; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D007221:Industry; D008168:Lung / Q000503:physiopathology; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced* / Q000503:physiopathology; D016273:Occupational Exposure / Q000009:adverse effects*; D011792:Quebec; D012140:Respiratory Tract Diseases / Q000139:chemically induced* / Q000503:physiopathology; D012307:Risk Factors; D013147:Spirometry; D013997:Time Factors
chemical_list: D002713:Chlorine