Effects of high ambient temperature on judgments of air quality.

Abstract

Such factors as sky color, sun angle, and amount of foreground in the visual field influence judgments of air quality even though physical quantities of pollutants in the air remain constant ( 1 ) . The present study sought to determine whether high ambient temperature would also influence judgments of air quality in urban landscspes. Subjects were 31 male and 33 female students in introductory psychology who participated to satisfy a course requirement. In a 9-ft. (2.74-m) x 12-ft. (3.66-m) room, they viewed 40 randomly ordered slides of urban scenes differing in levels of pollution and rated each slide on an air quality scale of very good ( 1 ) to very poor (21 ) . Half the subjects viewed the slides in a cool (73F, 23°C) setting and half in a hot (95F, 35°C) setting (with 43% humidity in both cases). Analyses of variance ( p < .01) performed on the ratings for each of the 40 slides, with temperature and sex of subject as independent variables, indicated no sex differences and no interactions, and only one slide showed a significant temperature effect. At a less conservative p < .05, four additional main effects for temperature were present. For each of these cases, subjects seated in the cool temperature rated the slide as having poorer air quality than did subjects in the hot temperature. Especially given the likelihood of Type I errors, the tesults suggest that ratings of air quality mere largely independent of discomfort associated with conditions of high ambient temperature. Past studies showing bias in judgments of air qualicy have examined factors in the composition of a landscape, such as sky coloration and amount of foreground in the photograph ( 1 ) . Especially in a laboratory where there is no reason to believe that the lab temperature is the same as that in the scene being evaluated, s u b jecrs appear to base air quality judgments on components of the scene, independently of ambient temperature.