Circadian variation of F.E.V. in shift workers

Abstract

M. (1969). Brit. J. industr. Med., 26,[121][122][123][124][125]. Circadian variation of F.E.V. in shift workers. The one-second forced expiratory volume (F.E.V.1.0), the forced vital capacity, and the oral temperature were measured in a group of men working a rotating three-shift system-2 to 10 p.m. one week, 10 p.m. to 6 a.m. the next week, and 6 a.m. to 2 p.m. the third week. The outside air temperature at the London Weather Centre was also obtained. Measurements were made on Mondays and Fridays at the beginning, middle, and end of the shift.The mean F.E.V.L.O of 19 normal men showed an increase of 0 15 litre (4-1 %) between the beginning and end of both the morning shifts, a mean decrease of some 0 05 litre (1I5 %) between the beginning and end of the afternoon shifts, and little change during the night shifts. This circadian variation could not be attributed to industrial fume, smoking or a learning effect.The findings will be of practical importance when F.E.V. is measured in shift workers to determine the effects of toxic substances on ventilatory capacity.Previous studies indicate that there is a circadian variation of ventilatory capacity (Lewinsohn, Capel, and Smart, 1960;McDermott, 1966; McKerrow, McDermott, Gilson, and Schilling, 1958;Bouhuys, Hartogensis, and Korfage, 1963; Walford, Lammers, Schilling, van den Hoven van Genderen, and van der Veen, 1966). A survey of the forced expiratory volume of a group of men working a rotating three-shift system has been made in order to obtain more precise information. Oral temperature was also measured to determine whether there is an association between the circadian variation of oral temperature (e.g., Kleitman, 1963) (174 cm.), with a range of 5 ft. 3 in. (160 cm.) to 6 ft. 5 in. (196 cm.). All the men were Caucasians.

Short-term ventilatory effects in workers exposed to fumes containing zinc oxide: comparison of forced oscillation technique with spirometry

“…Maximal expiratory volumes and flows demonstrate a circadian rhythm, characterized by a decrease of all values at night [13]. However, the night shift is not associated systematically with larger decrements of pulmonary function [14]. In a study performed on more than 1,000 unexposed bluecollar workers, GHIO et al [15] were not able to provide evidence for a different influence of day or evening shifts either on FEV1 or PEF.…”

Acute Pulmonary Function Change Associated With Work on Large Dairies in California

“…16,17 For the dichotomous shift-time variable, 12 PM was used as the cutpoint on the basis of the control workers' shift-start times. Because of varying work-shift lengths, we also considered whether the length of the work shift impacted lung function.…”

Respiratory Symptoms and Lung Functional Impairments Associated with Occupational Exposure to Asphalt Fumes

“…These changes could not be attributed to the circadian rhythms considering the circadian rhythms lead to changes in opposite direction. 33 The observed changes could be attributed to asphalt fumes-induced acute partially reversible decrements in pulmonary function tests. This conclusion is further confirmed by the results of multiple linear regression analysis (Table 5) and is consistent with the findings of other studies.…”