Eighty‐four persons with bronchial asthma were selected for a daily follow‐up study in Nashville, Tennessee, in an effort to determine whether they showed variation in the frequency and severity of their attacks which could be associated with variation in their exposure to environmental air pollutants. The aerometric data used for the yearlong study were unusually plentiful.
The most striking finding of the multivariate analysis was the role of the variable, day of study. The next most important variable was the sulfur dioxide level in the atmosphere.
A number of significant limitations of the data were noted.