Acute exposures to hemp dust, in healthy subjects as well as hemp workers with @entity3312 , resulted in two different responses. @entity1 with symptoms (chest tightness, coughing, and wheezing) after exposure showed decreases of forced expiratory volumes (FEV(1.0)), flow rates on maximum expiratory flow-volume (MEFV) curves, and of vital capacity (VC), while airway conductance (Gaw: TGV ratio) did not decrease significantly ("flow rate response"). @entity1 without symptoms after exposure showed no changes of VC, FEV(1.0), and MEFV curves, but had a significantly decreased airway conductance ("conductance response"). The flow rate response is attributed to a pharmacological bronchoconstrictor effect of hemp dust on small airways, the conductance response to a mechanical or reflex effect of hemp dust on large airways. Both responses were abolished by a bronchodilator drug. The type of response reflects a difference between individuals and is not related to age, smoking habits, or prior exposure history. @entity1 with normal control function data had either a flow rate or a conductance response. All @entity1 with abnormal control data had a flow rate response.Long-term hemp dust exposure causes irreversible @entity3885 , in particular among @entity1 who respond to acute dust exposure with symptoms and flow rate decreases. The detection of this response, with FEV(1.0) measurements and MEFV curves, is essential in the study of @entity3312 . Decreases of airway conductance after dust exposure have no consistent relation to the development of clinical symptoms. The relative value of measurements of maximum expiratory flow rates and of airway conductance in other @entity358 needs to be reassessed.

Respiratory mechanics and dust exposure in XXXX .

@entity1 :: ('9606', 'Species') :: ['Men', 'men'] @entity358 :: ('MESH:D008171', 'Disease') :: ['lung diseases'] @entity3885 :: ('MESH:D008173', 'Disease') :: ['obstructive lung disease'] @entity3312 :: ('MESH:D002095', 'Disease') :: ['byssinosis']
@entity3312 :: (MESH:D002095,Disease) :: ['byssinosis']
