PT  - JOURNAL ARTICLE
AU  - Catherine Lemiere
AU  - Denis Bégin
AU  - Michel Camus
AU  - Amélie Forget
AU  - Louis-Philippe Boulet
AU  - Michel Gérin
TI  - Occupational risk factors associated with work-exacerbated asthma in Quebec
AID  - 10.1136/oemed-2012-100663
DP  - 2012 Dec 01
TA  - Occupational and Environmental Medicine
PG  - 901--907
VI  - 69
IP  - 12
4099  - http://oem.bmj.com/content/69/12/901.short
4100  - http://oem.bmj.com/content/69/12/901.full
SO  - Occup Environ Med2012 Dec 01; 69
AB  - Background There is limited information regarding the occupational exposures of subjects with a diagnosis of work-exacerbated asthma (WEA). Objectives To: (1) identify potential specific occupational, chemical, biological and physical agents associated with incident cases of WEA and (2) compare these agents with occupational exposures of occupational asthma (OA) and non-work-related asthma (NWRA) cases. Methods Subjects were workers with work-related asthma (WRA) or NWRA referred between 2005 and 2008 to two Quebec clinics specialised in the field of WRA. Specific inhalation challenges were performed to differentiate OA from WEA. Work exposures were assessed using a detailed occupational questionnaire. Exposures to 41 chemical and biological agents were coded in a semiquantitative way according to a combination of indices for concentration in workplace air, frequency and confidence of exposure by an occupational hygienist expert in occupational exposure coding. This expert was blind to the medical status of WEA, OA or NWRA. Five physical agents were coded on a yes/no scale. Results 153 subjects were enrolled (53 WEA, 67 OA and 33 NWRA). WEA cases were significantly more exposed to ammonia, engine exhaust fumes, silica, mineral fibres, aerosol propellants and solvents, and significantly less exposed to animal derived dust and enzymes than were OA cases. Exposure to physical conditions did not differ between WEA and OA. Conclusions Exposures associated with WEA differ from those associated with OA in this study. A proportion of subjects with WEA may suffer from low-dose irritant asthma, which remains a hypothesis to be tested.