Figure 2.
Distribution of NO2 concentrations by school, by season. X axis represents each individual school, number of subjects attending each school is in parentheses (). Box and whiskers plots represent the distribution of NO2 across multiple classrooms within each school. Box parameters are the IQR, hash mark is the median, whiskers extend to 1.5 times the IQR above the 75th and below the 25th percentile.