Figure 1.

Distribution of (A) birthweight and time-weighted (B) PM₂_·₅, (C) black carbon, and (D) carbon monoxide

The corresponding numeric data are provided in the appendix (p 4). Results are presented separately for each study site and in combination for the entire trial. Dots are individual datapoints. X-axes are log transformed in panels B, C, and D. Thick solid lines inside the boxes are the medians. The lower and upper hinges (ie, the ends of the boxes) correspond to the 25th and 75th percentiles. The whiskers (ie, the lines beyond the boxes) extend from the hinge to 1·5 IQR. The panel-wide dotted vertical lines are study-wide medians. In panel A, the shaded area indicates low birthweight (<2500 g). In panel B, the dashed line is the WHO interim target level one annual guideline value of 35 μg/m³.