By Marc Campopiano and Max Friedman

On March 6, 2015, the California Office of Environmental Health Hazard Assessment (OEHHA) updated its Guidance Manual for Preparation of Health Risk Assessments (HRAs) for the purpose of better characterizing exposure risks to children from air toxics.  Using the new Guidance Manual, HRAs are expected to estimate risks that are two to five times greater than HRAs using the former methodology—even assuming no changes in air toxics exposure.  As a result, once the updated