Significance of Age and Physical Fitness for the Stressing of Subjects in Complex Exposure Situations

Abstract

Although it would be very valuable in preventing health hazards, we have only limited knowledge of the effects of age and physical fitness on the strenuousness of exposure situations and on the duration of recovery periods. Therefore, this study was set up to examine the differences in the subjective experience of stressfulness between persons of different ages and physical fitness levels, when the subjects were exposed either separately or simultaneously to noise, whole body vibration, physical dynamic muscular work and mental competition type work at relatively high ambient temperatures. The subjects were males representing three age groups: under 25, 26 to 39 and over 40 years of age. The study was performed in a special exposure chamber, and it involved a total of 192 subjects. One personal test took 5½ hours and consisted of several consecutive exposure periods of 16 min. During the test the subjects rated their feelings of stressfulness four times using a five-class scale. The physical fitness of the subjects was tested with a bicycle ergometer, and the results were used to calculate the physical working capacity (PWC170-value) and the maximum oxygen intake (VO22 max-value). The report discusses the results and draws conclusions on the evaluation of complex exposure situations. Some suggestions are made as to the practical application of the results in standardization work considering the combined effects of noise and vibration.