Prevention of Work-related Asthma: Study Search Results

Study Details

Prevention Level	Secondary
Author	Tarlo
Study Year	1997
Country	Canada
Molecular Weight of Agent	LMW
Category	Diisocyanates
Agent	Isocyanates
Occupation	Workers in general population (Includes cohort reported by Tarlo, 1995)
Outcome/Diagnosis	Occupational asthma
Activity Intervention	Comparison of OA claims b/w 1984-1988 from isocyanate exposure, which has medical surveillance program (1983), versus OA claims from other exposures that do not have medical surveillance programs. Medical surveillance measures for isocyanates were introduced by legislation and consisted of pre-employment respiratory questionnaire, repeated respiratory questionnaires every 6 months, and spirometry at least on annual basis. Legislation also required monitoring of diisocyanate concentrations to maintain 8-hr time average concentrations of 5 ppb and short-term concentrations below 20 ppb.
Participation Rate	Researchers retrospectively reviewed compensated claims (n=235) for OA between mid-1984 and mid-1988 by the Ontario Workplace Safety and Insurance Board
Intervention Effectiveness	Workers with OA due to isocyanates had shorter latent period before onset, shorter duration of symptoms before diagnosis, and less associated atopy (p<0.05) than for OA due to other causes. Better prognosis for OA due to isocyanates was associated with early diagnosis (p<0.05) and early removal from exposure. Earlier diagnosis for isocyanate induced OA was observed in workers from companies in compliance with surveillance measures (p<0.05).