I'm not surprised. My daughter's school is in the 6th percentile (6,001 of 127,809 schools have worse air.) We live in a county in northwest Indiana that has several steel mills, a BP/Amoco oil refining plant, a chemical factory less than five miles away, a Lever Bros. soap factory, a Cargill plant (my husband works there), and is notoriously inefficient at penalizing those who don't adhere to air safety regulations.

Edit: I should add, for purposes of comparison, that the Iowa high school where I attended ranks in the 32nd percentile (40,228 of 127,809 schools have worse air.)