Background: Environmental health, a crucial part of our everyday lives, is a multidisciplinary field with many discrepancies as to what encompasses the core areas. Purpose: This study intended to establish core areas and corresponding topics of environmental health as a preliminary step to identifying knowledge, attitude and behavior questions for use in needs assessment and program planning. Methods: Fourteen to sixteen experts in various fields of environmental health participated in a modified three-round Delphi Technique. Results: Experts established 11 core areas and 25 corresponding topic areas, and identified 443 potential questions for environmental health survey development. Discussion: The core areas, topic areas and corresponding survey questions were produced to be applicable for people in all areas of United States. This is important for continuity within the field to have a universal tool to measure awareness across the country. Translation to Health Education Practice: Standardizing the core areas and specific topics of environmental health may assist practitioners in conducting thorough needs assessments and guide program planning and research. (Contains 3 tables.)