Influence of anxiety level on work performance with and without a respirator mask.

Work performance of mask wearers has been shown to be less than performance of the same individuals without masks. How much this performance decrement is attributable to psychological factors was the subject of this study. This experiment was designed to give quantitative information about the effect of anxiety level on relative work performance while wearing a respirator mask. Twenty subjects were tested for trait anxiety levels and performed on a treadmill at 80-85% of their maximum heart rates until they reached voluntary end-point. Physiological, metabolic, and subjective measurements were taken every minute. While experimental variability precluded many of the results from achieving statistical significance, performance times with the mask averaged less than without the mask. Anxious subjects experience more discomfort, perform for shorter times, and accomplish less total work than their lower anxiety counterparts, even when rate of work can be adjusted.

Task performance with visual acuity while wearing a respiratory mask.

Forty-six subjects were required to perform a console-monitoring and two hand-eye coordination tasks while wearing masks with lenses clouded to give seven levels of visual acuity. The console-monitoring task performance was found to be the most sensitive to visual acuity, followed by the random hand-eye coordination task. These results can be used to help predict performance degradation when lenses become clouded due to condensation or particulate deposition.

Performance decrement due to altered vision while wearing a respiratory face mask.

The purpose of this investigation was to determine performance decrement due to altered vision while wearing a respiratory face mask. Lenses clouded to visual acuities of 20/64, 20/38, 20/34, 20/28, 20/23, 20/20, and 20/15 were applied to each mask while subjects performed a battery of vision tests involving tracking and hand-eye coordination skills. Generally, performance decrement followed a significant curvilinear pattern as visual acuity worsened. These findings warrant the need to investigate the transfer of this performance decrement to skills that are inherent to military-type tasks.

Preventive health strategies and the policy makers' paradox.

The likelihood of developing many diseases is predicted by levels of risk factors. Many public health strategies have been created to apply interventions (for example, drugs, diets, exercise) intended to lower levels of these factors and thereby prevent disease. Often, these strategies are based on the interpretation of incomplete evidence for the effectiveness of the interventions. The reason this evidence is and will likely remain incomplete is explained by the policy makers' paradox. The paradox occurs when evidence for an intervention's effectiveness is obtained in persons with the highest levels of a risk factor, but the application of the intervention may have the greatest potential for reducing disease burden in persons with lower levels. Resolution of the paradox requires consideration of the type and quality of evidence, the society's time preference for risk, and the society's choice about allocation of scarce resources.