Simultaneous multiple stressors in the environment: physiological stress reactions, performance, and stress evaluation.

Interactive effects of two environmental stressors when simultaneous ly present, i.e., noise and crowding, were analyzed. Four experimental conditions with two intensities of stress for each stressor (high versus low) were created. The stressors were concurrently introduced in laboratory conditions and their effects analyzed using several methodological approaches. More intense and negative effects were expected when the two highest intensities of noise and crowding concurred. 40 people (20 men and 20 women) participated in a study with a 2 x 2 factorial design. Analysis showed an increase in the measures of hemodynamic, endocrine, and neuroendocrine values of participants after being exposed simultaneously to noise and crowding. Similarly, their performance on complex tasks decreased, and they reported a subjective increase in stress. Capacity to cope was indicated by a statistically significant lower mean on the Dimension of Stress scale, tolerance of frustration during the multiple stress condition.