[Quantification of inhaled exposure to alpha-amylase in 2 bakeries].
BACKGROUND
Baker's asthma and baker's rhinitis are among the most frequent occupational diseases. A major cause is the high exposure to flour dust in the workplace and to allergenic enzymes like alpha-amylase from Aspergillus oryzae (allergen name: Asp o 2).


METHODS
To quantify allergen exposure in the workplace, 31 personal dust samples in a conventional small bakery (six workers) and in a biobakery (seven workers) were collected. Using a recently developed two-site enzyme-linked immunosorbent assay based on monoclonal antibodies to alpha-amylase from Aspergillus oryzae, the allergen content of these dust samples was determined.


RESULTS
Dust exposure in the biobakery was in the range between 3.5 and 12 mg/m3 (median: 5.2 mg/m3) and in the conventional bakery between 0.9 and 118 mg/m3 (median 8.5 mg/m3). 23 out of 31 exposure measurements showed values higher than 4 mg/m3 (threshold limit value for inhalable dust). In the biobakery, no fungal alpha-amylase could be detected. 15 out of 17 samples taken in the conventional bakery contained fungal alpha-amylase in the range between 0.2 and 88 ng per mg dust. The geometric mean of alpha-amylase exposure in this bakery was 13 ng Asp o 2/m3, and the maximum exposure was 4.8 micrograms/m3. In four cases, fungal alpha-amylase was detected although exposure to dust was below the threshold limit of 4 mg/m3.


CONCLUSIONS
This study in two German bakeries shows that preventive measures to reduce contact to allergens have not been sufficiently realised. Relevant alpha-amylase exposure occurred at low dust levels illustrating that dust measurements are not adequate to control alpha-amylase exposure. For fungal alpha-amylase an additional threshold limit should be established.
Sander
I
I
Berufsgenossenschaftliches Forschungsinstitut für Arbeits-medizin (BGFA), Institut an der Ruhr-Universität Bochum. Sander@bgfa.ruhr-uni-bochum.de
Neuhaus-Schröder
C
C
Raulf-Heimsoth
M
M
Doekes
G
G
Heederik
D
D
Baur
X
X
D001236:Aspergillus oryzae; D001249:Asthma / Q000209:etiology*; D004391:Dust / Q000009:adverse effects / Q000032:analysis; D005525:Food-Processing Industry; D005858:Germany; D006801:Humans; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis*; D000516:alpha-Amylases / Q000009:adverse effects / Q000032:analysis*
D004391:Dust; D000516:alpha-Amylases
Quantifizierung der inhalativen Belastung mit alpha-Amylase in zwei Bäckereien.