Occupational respiratory allergy in bakery workers: A review of the literature

Abstract

Baker's asthma has long been recognized as a serious disease among workers in the bakery industry and the number of cases with baker's asthma is steadily increasing. This paper presents a review of the available literature on baker's allergy with a special focus on the allergens involved, the epidemiologic research and issues on exposure assessment, evidence of exposure‐response‐relationships, and possible prevention strategies. A large number of potential allergens have been identified and are described here. At present little is known about the incidence of baker's allergy. On the other hand, a large number of cross‐sectional studies have been performed, showing that sensitization and work‐related symptoms are common among bakery workers. Only atopy and exposure level have consistently been reported as determinants of this occupational disease. Age, gender, and smoking habits do not seem to be associated with sensitization or work‐related respiratory symptoms. Recently, immunochemical methods have been developed to measure specific allergens in the bakery industry, which have been used to unravel the role of allergen exposure in the development of baker's asthma. Clear exposure‐response‐relationships have been found. The implications of these recent findings for prevention strategies and standard setting are discussed. Am. J. Ind. Med. 34:529–546, 1998. © 1998 Wiley‐Liss, Inc.

Baker's asthma: causes and prevention

“…Several studies have demonstrated a wide variety of time-weighted dust loads in bakeries, ranging from about 1 up to 10 mg/m 3 [9,13,24,25]. The highest load can be found during doughmaking and breadforming.…”

Nasal symptoms and indices of nasal inflammation in flour-dust-exposed bakers

“…The respiratory morbidity is partly due to allergic, IgE-mediated sensitization to¯our proteins and additives. In cross-sectional studies, 29±50% of rhinitic bakers were sensitized to occupational allergens [6,10,22], whereas in a longitudinal study, only 2 of 45 bakers with work-related rhinoconjunctivitis with onset during the ®rst 4 years of bakery work were sensitized to¯our [5]. Thus, nonallergic mechanisms are also likely to be involved in respiratory tract disease among bakers.…”

Specific inhalation challenge with wheat flour in workers with suspected baker's asthma

“…For wheat¯our, however, there is no clear standard. If wheat¯our is considered a``nuisance dust'', a possible reference limit value could be 10 mg/m 3 as the TLV-TWA, a ®gure seldom exceeded in bakeries and¯our mills [5]. The few data available about airborne¯our-dust levels during challenge show that only with recently developed close-circuit devices is it possible to keep the concentration of inhaled particles low and relatively constant [1,7].…”