Abstract
BACKGROUND: A review of Workplace Safety and Insurance Board (WSIB) claims in Ontario from 1998 to 2002 showed an unusual spike in the number of claims accepted for work-exacerbated asthma (WEA) in April 2001.OBJECTIVE: To identify the cause for the spike in the number of WSIB claims for WEA in April 2001.METHODS: File reviews were performed to identify the occupations of workers with claims accepted for WEA in April 2001 compared with claims during March and May 2001, and during the same months in 2000 and 2002.RESULTS: In April 2001, there were 61 accepted WEA claims; the most common occupation was ‘teacher’. In contrast, among educational workers, there was only one WEA claim in the previous month and one in the following month. From March to May in the preceding and following years, there were only four and two claims, respectively. The most frequently implicated causative agents were dust and dirt exposure, which were responsible for 98% of claims; the mean (± SD) number of lost workdays was 6.5±10. The only identified environmental change associated with this spike was a cleaners’ strike at all elementary and high schools in the Toronto District School Board in Ontario, which started on March 31, 2001 and ended on May 1, 2001.CONCLUSION: The spike in accepted WEA claims in Ontario in April 2001 was temporally associated with a strike by Toronto District School Board cleaners, suggesting acute symptomatic effects of poor workplace (school) maintenance on asthmatic employees. The WSIB database was sufficiently sensitive to capture this phenomenon.