Objectives: This study investigated the value of powered dust respirator helmets in the treatment of farmers with occupational asthma.
Methods: The study population consisted of 33 asthmatic agricultural workers, 24 with occupational asthma induced by cow dander or grains, 2 with other forms of atopic asthma, and 7 with nonatopic asthma. The efficiency of a powered dust respirator helmet with a P2-class filter in preventing asthmatic symptoms was assessed for 1 year. Morning and evening peak expiratory flow rates and daily symptoms of the subjects were monitored for 3 months without the use of the helmet and for 10 months with the helmet.
Results: Objective evidence of protection was obtained for farmers with occupational asthma. The morning peak flow rate increased and the variation in daily peak flow rate and the symptoms of cow-barn rhinitis diminished significantly during the helmet period. In the group of farmers with nonatopic asthma there was no improvement in peak flow rate or symptoms of asthma, although some of these farmers also seemed to benefit from helmet use.
Conclusions: The results of this study suggest that especially dairy farmers with occupational asthma benefit from the use of a powered dust respirator helmet.