Effect of an intervention aimed at reducing the risk of allergic respiratory disease in bakers: change in flour dust and fungal alpha-amylase levels.

INTRODUCTION: We evaluated the effect on exposure of an intervention programme, which focused on risk education and providing information on good work practices. This intervention programme was enrolled as part of a Dutch covenant in the flour processing industry (industrial bakeries, flour mills, ingredient producers). METHODS: Data from several measurement surveys collected pre- and post-intervention were used to evaluate changes in exposure over time. All datasets contained personal measurements analysed for flour dust and fungal alpha-amylase contents, and contextual information was available on process characteristics, work practice, and use of control measures. RESULTS: Changes in exposure over time varied substantially between sectors and jobs. For bakeries a modest downward annual trend of -2% was found for flour dust and -8% for amylase. For flour mills the annual trend for flour dust was -12%; no significant trend was observed for amylase. For ingredient producers results were generally non-significant but indicated a reduction in flour dust exposure and increase in fungal alpha-amylase exposure. Modest increase in use of control measures and proper work practices were reported in most sectors, especially the use of local exhaust ventilation and decreased use of compressed air. CONCLUSIONS: The magnitude of the observed reductions in exposure levels indicates that the sector-wide intervention strategy implemented during the covenant period had a limited overall effect. This indicates that a more rigorous approach is needed to substantially decrease the exposure levels to flour dust and related allergens and, respectively, the prevalence of associated occupational diseases.