Ever wonder what goes on in an Advanced Placement Environmental Science Class? Students in Jennifer Mercure’s class at Lassiter High School are conducting tropospheric ozone (ground level or “bad” ozone) tests around the school campus that reinforce lessons learned in class.
Students collected ozone samples using a special paper they prepared with cornstarch and potassium iodide solution. This paper experiences color change when exposed to ozone and students measure the level on the 0-10 Schoenbein color scale. This number is then compared to the humidity level. On the day tested, excellent results were determined at Lassiter High School with minimal color changes from no change to pale pink of 0-2, which corresponds to level of 0 – 70 ppb ozone at a humidity level of 45% average.
This was the case in most areas inside the school, so it appears that Lassiter’s custodians and building engineer are doing a fabulous job cleaning up post construction and changing air filters regularly to provide air filtration. High outdoor ozone levels were found near the construction areas, such as the outdoor areas at the front of the school. The color changes here were medium to dark purple (7-10 on the Schoenbein scale) measuring levels 150-160 ppb ozone at our humidity of 45% average. Want to learn more about tropospheric ozone? Click here to learn more from the EPA.
(Reprinted from http://cobbcast.cobbk12.org/?p=4899. Submitted by Ashlynn Campbell, assistant principal, Lassiter High School)