Bakery, pastry-cooking, and hairdressing are occupations at risk of asthma. Airways inflammation occurs soon after inception of exposure. This study assesses how asthma-like symptoms develop along the first years of activity among young workers.
Following a retrospective follow-up design, 6 cohorts of bakers or pastry cooks and hairdressers of increasing time since admission in 9 vocational schools (2001–2006) underwent telephone interviews on the occurrence of respiratory symptoms. A group of young workers who graduated in the same schools in 2001 and had occupations not exposed to known airways irritants or allergens served as a reference group.
Eight hundred twenty-six subjects were interviewed (mean age of 25.5 years, 44.4% females). The prevalence of asthma-like symptoms is greater among bakers or pastry cooks and hairdressers than among the referent group (15.8% and 19.6% vs. 9.4%, respectively, P = 5%), as well as ENT symptoms (11.3 and 12.8 vs. 2.1, P = 1%). Asthma-like symptoms show an increasing trend with duration of exposure since entry in apprenticeship of bakers or pastry cooks (prevalences step from 11 to 21% along the 4 quartiles of the duration distribution [from 36 to 115 months], P for trend = 4%), with similar findings for ENT symptoms. Prevalences, already high in the first exposure duration category, stay even long time among hairdressers. In a subsample of subjects who underwent home medical visits (n = 165), fractional concentration of exhaled nitric oxide values are greater among subjects exposed to flour dust (17.3 ppb [SE = 14.0], 11.6 [7.0] and 9.8 [4.5], respectively, across the 3 occupation categories, P = 0.001).
Incidence of asthma-like symptoms starts soon after engaging in bakery, pastry cooking, and hairdressing, especially early among subjects in the latter whose activity entail exposure to low molecular weight agents, and with some delay among the former, an observation that might express different underlying mechanisms.