Herons persist in Chicago wetlands despite exposure to banned chemicals Jan 16, 2008 8:00 am by Mickalei Lindquist, Illinois Natural History SurveyNatural History Survey Share on Facebook Tweet Email Results of a study led by INHS wildlife toxicologist Jeff Levengood were published in the latest issue of the Journal of Great Lakes Research. The study reports that Chicago-area herons are still being exposed to banned pesticides. Share on Facebook Tweet Email