Peak flow rate in relation to forced expiratory volume in hemp workers.

v Zuskin, E., and Vali, F. (1971). Brit. J. industr. Med., 28, 159-163. Peak flow rate in relation to forced expiratory volume in hemp workers. Measurements of the forced expiratory volume in one second (FEV1.0) and the peak expiratory flow rate (PEF) were made in 99 non-smoking female hemp workers before and after the shift. A significant mean reduction of both FEV1.o and PEF (P < 0-01) over the shift was found in workers both with and without byssinosis but the relative reductions of PEF were more pronounced (FEV1.0 15 3 %; PEF 20-8 %). Therewas a significant positive correlation (P< 0 *01) bothbetween absolute FEV1 .0 and PEF values measured before work (with byssinosis r = 0-605; without byssinosis r = 0-461), and between FEV1.O and PEF changes over the shift (with byssinosis r = 0-725; without byssinosis r = 0-631). There was also a significant correlation between FEVI.o and PEF changes following Alupent inhalation after the shift with more pronounced effects on PEF. The coefficients of variation in FEV1.o and PEF measurements (by the Bernstein type spirometer and the Wright peak flow meter) proved approximately equal.