PHA Process Basic Components

This graphic depicts the five components of the PHA Process. The components listed from left to right. Component 1 – Triggers. Including Petition, National Priorities Listing, and Other Agency Requests. Component 2 – Data and Information. Including Sampling Data, Exposure Data, Health Effects Data, and Community Data. Component 3 – Scientific Evaluations. Including Exposure Pathways (Exposure Units*), Screening, EPCs and Exposure Calculations, and In-Depth Toxicological Effects. Component 4 – Products. Including Public Health Assessment, Health Consultation, Letter Health Consultation, Exposure Investigation-Health Consultation, Health Advisory, and Technical Assist. Component 5 – Outcomes. Including Follow-Up Health Actions and Technical Assistance to Other Agencies.

*Based on site-specific information, health assessors may define an exposure unit (if appropriate) before or after the screening analysis. Health assessors will use professional judgement to determine when to define exposure units; however, they must define them before determining EPCs.