Fig. 2

Change in exhaled breath condensate (EBC) nitrite + nitrate (NOx) between pollution and clean air testing days. The value on the Y axis is the difference between pollution and clean air testing days. Schematic box-and-whiskers plots define values as the following: Interior boxes display 25^th percentile, median, 75^th percentile and mean (filled circle). Whiskers extend to most extreme data values within 1.5 IQR (interquartile range) from 25^th and 75^th percentiles. More extreme data values are indicated by open squares