Valić, F., and Žuškin, E. (1973).British Journal of Industrial Medicine,30, 381-384. Pharmacological prevention of acute ventilatory capacity reduction in flax dust exposure. The protective effect of the preshift application of a bronchodilator (orciprenaline), an antihistamine drug (diadril), and ascorbic acid on flax-induced acute bronchoconstriction was studied in 13 byssinotic and 7 non-byssinotic female workers exposed to airborne fibres of biologically retted flax. Orciprenaline was applied by inhalation, while diadril and ascorbic acid were given orally. All the three drugs exerted a significant preventive effect, diminishing the acute fall of ventilatory capacity during the shift. The fall in forced expiratory volume (FEV1·0) was reduced by 50% and the fall in maximal flow rate at 50% vital capacity (V̇max 50% VC) by over 65%.