Physician reports of work-related asthma in California, 1993-1996

Am J Ind Med. 2001 Jan;39(1):72-83. doi: 10.1002/1097-0274(200101)39:1<72::aid-ajim7>;2-0.


Background: Work-related asthma is a leading cause of occupational respiratory illness.

Methods: Work-related asthma was studied in California over a 36-month period, from March 1, 1993 to February 29, 1996. The surveillance system identified cases from Doctor's First Reports (DFRs), a mandated physician reporting system. Structured follow-up telephone interviews of DFR asthma cases were conducted to collect work history, exposure, and medical information. Statewide employment data was used to calculate disease rates among industry groups.

Results: Based on 945 cases of work-related asthma, the average annual reporting rate for work-related asthma in California was 25/million workers. We estimate that the actual rate is 78/million, adjusted for likely underreporting. Janitors and cleaners (625/million) and firefighters (300/million) had the highest reporting rates of work-related asthma. Half of all work-related asthma cases were associated with agents not known to be allergens.

Conclusions: A greater proportion of work-related asthma associated with irritant exposures was identified than has previously been reported. The surveillance data provide a very conservative estimate of the incidence of work-related asthma.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Asthma / epidemiology*
  • California
  • Chi-Square Distribution
  • Employment
  • Female
  • Fires
  • Follow-Up Studies
  • Humans
  • Incidence
  • Industry / classification
  • Interviews as Topic
  • Irritants / adverse effects
  • Logistic Models
  • Male
  • Mandatory Reporting
  • Occupational Diseases / epidemiology*
  • Occupational Exposure
  • Odds Ratio
  • Physicians
  • Risk Factors
  • Sanitation
  • Sentinel Surveillance


  • Irritants