Fig. 3.

Day of the week and seasonal box plots for a) nitrate, b) sulfate, c) OC and d) EC. The boxes depict the median (dark line), inner quartile range (shaded box), 10th and 90th percentiles (whiskers) and the mean (asterisk). The dashed line across the plot is the overall median. The individual median values and the number of points contained within each box are listed below the boxes.