title: A thirteen-year follow-up of respiratory effects of acute exposure to sulfur dioxide.
abstract: OBJECTIVE
  In 1977, nine men were accidentally exposed to sulfur dioxide in an explosion in a pyrite mine. The lung function of seven men was followed after the accident. A four-year follow-up has been published previously. The greatest decrease in forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and maximal midexpiratory flow (MMEF) was observed one week after the accident, after which all these parameters improved without reaching the preaccident level. Reversible bronchial obstruction was still present in three patients, and a positive reaction in the histamine challenge test was found for four. In the present paper, the lung function follow-up 13 years after the accident is reported for six men.
  
  
  METHODS
  The patients' clinical condition, chest X-ray, spirometry, and histamine challenge test were studied 13 years after the incident.
  
  
  RESULTS
  Spirometry was normal in one worker, two displayed obstruction, and three had a combined obstructive and restrictive, mainly obstructive, ventilatory impairment. In the histamine challenge test, four patients showed bronchial hyperreactivity, one with a nearly significant reaction. Because of bronchial obstruction one patient could not perform the challenge test.
  
  
  CONCLUSIONS
  This 13-year follow-up showed that acute inflammatory obstruction caused by exposure to sulfur dioxide left, as sequelae, obstructive impairment of ventilatory function and permanent bronchial hyperreactivity. The clinical picture displayed by these patients was named the "reactive airways dysfunction syndrome" (RADS) in 1985. Four of the patients also showed symptoms of chronic bronchitis.
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: P L
authors.initials: PL
authors.lastname: Piirilä
authors.forename: H
authors.initials: H
authors.lastname: Nordman
authors.forename: O S
authors.initials: OS
authors.lastname: Korhonen
authors.forename: I
authors.initials: I
authors.lastname: Winblad
mesh_terms: D000208:Acute Disease; D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects*; D016535:Bronchial Hyperreactivity / Q000139:chemically induced*; D005500:Follow-Up Studies; D006801:Humans; D007501:Iron; D008173:Lung Diseases, Obstructive / Q000139:chemically induced*; D008297:Male; D008875:Middle Aged; D008906:Mining; D009784:Occupational Diseases / Q000139:chemically induced*; D016273:Occupational Exposure; D012129:Respiratory Function Tests; D013440:Sulfides; D013458:Sulfur Dioxide / Q000009:adverse effects*
chemical_list: D000395:Air Pollutants, Occupational; D013440:Sulfides; D013458:Sulfur Dioxide; C011342:pyrite; D007501:Iron