Frequency of work-related respiratory symptoms in workers without asthma

Am J Ind Med. 2009 Jun;52(6):447-54. doi: 10.1002/ajim.20695.


Background: Clinicians are faced with subjects complaining of work-related respiratory symptoms (WRS) without any evidence of asthma. We sought to assess the prevalence of subjects with WRS without asthma in a cohort of workers referred for possible work-related asthma (WRA) as well as compare the characteristics and the work environment of subjects with WRS to subjects with WRA.

Methods: A prospective observational study of workers referred for possible WRA over a 1-year period. Detailed medical and occupational questionnaires were administered. Pulmonary function tests as well as specific-inhalation challenges were performed.

Results: One hundred twenty workers were investigated. Fifty-one had WRA while 69 had WRS. The type and the severity of the respiratory symptoms were similar in both groups, except for wheezing which was more frequently reported in subjects with WRA (32 (62.7%)) than in subjects with WRS (16 (23.2%)) (P < 0.01). Both the workers with WRS and WRA were mainly employed in the manufacturing sector (64.7% (WRA) and 71% (WRS)). At the time of the first assessment 64.7% of subjects with WRA and 56.5% with WRS had left their workplace because of their bothersome respiratory symptoms.

Conclusions: Subjects with WRS without asthma represent a large proportion of the subjects assessed in clinics specialized in the field of WRA. Like subjects with WRA, the population with WRS is likely to represent a significant medical burden. The similarity of the symptoms between the WRA and the WRS groups emphasizes the need to perform a thorough and objective investigation to diagnose WRA.

Publication types

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

MeSH terms

  • Adult
  • Air Pollutants, Occupational / adverse effects*
  • Air Pollutants, Occupational / analysis
  • Asthma / diagnosis
  • Asthma / epidemiology*
  • Cohort Studies
  • Female
  • Humans
  • Inhalation Exposure / adverse effects
  • Inhalation Exposure / analysis
  • Male
  • Occupational Diseases / diagnosis
  • Occupational Diseases / epidemiology*
  • Occupational Exposure / adverse effects*
  • Occupational Exposure / analysis
  • Prevalence
  • Prospective Studies
  • Quebec / epidemiology
  • Respiratory Function Tests
  • Respiratory Sounds
  • Respiratory Tract Diseases / diagnosis
  • Respiratory Tract Diseases / epidemiology*
  • Smoking
  • Surveys and Questionnaires
  • Workplace


  • Air Pollutants, Occupational