A reproducible method for analysing flour dust should enable accurate measurement of the allergens that give rise to bakers' asthma. 

Airborne flour dust can cause asthma in bakery and flour mill workers; many workers are sensitised to the proteins contained in flour. Methods for monitoring levels of these protein allergens can give widely varying results because there is no standard method for extracting the proteins from the flour. Jelena Bogdanovic and colleagues from Utrecht University, The Netherlands, have devised an accurate and reproducible method for extracting flour dust allergens, which should help in standardising exposure levels in bakeries. 

Bogdanovic and colleagues collected dust samples from eight European bakeries and flour mills, and compared various air filters, extraction procedures and concentration measurement methods to optimise the analysis process.

The researchers found that the best results were obtained by adding a surfactant to the solution before measuring the concentration of allergen. Bogdanovic said that this probably works because it improves release of proteins from the insoluble particles in the flour. She also suggested several less critical recommendations, such as using polystyrene tubes. 

The findings 'represent an important step towards standardisation of the allergen measurement technology in exposure studies,' said Bogdanovic. 

Andrew Garrod, from the Health and Safety Executive, Bootle, UK, agreed, saying, 'such methods provide the scientific foundation upon which to develop better regulatory decisions.' 

David Barden