Work-related asthma in Washington State.

Objective: Asthma is a common and costly public health problem. Occupational exposures contribute to the burden of asthma. Identifying workplace exposures and industries and occupations at risk can lead to more effective prevention measures.

Methods: Data from Washington State's work-related asthma (WRA) surveillance program from October 2001 to December 2008 were analyzed. Workers' compensation records, physician reports, and telephone interviews were used to describe the occurrence of WRA during this time, in order to identify contributing exposure sources and industries and occupations that are associated with WRA in Washington.

Results: There were 1343 identified WRA cases in Washington State during this time. Of these, 1285 were workers' compensation claims, with a total medical cost for State Fund claims of approximately $3 million dollars. The top three sources identified were miscellaneous chemicals and materials, mineral and inorganic dusts, and plant material. Plant material claims proved to be widespread throughout various industries, were largely classified as new-onset asthma cases, and had higher median medical cost and higher median time loss days than cases associated with other exposure sources.

Conclusions: Washington State has an abundance of plant-material-related WRA cases among US states conducting WRA surveillance. Washington State's industry mix might explain the higher prevalence of cases, particularly its logging and wood processing industries and as a world leader in hops production. In Washington, further WRA prevention efforts should emphasize workplaces working with plant materials.