Step 1. Conclusions

Public Health Hazard Conclusion Categories

The public health assessment team members evaluate all the information about the site. The team then assigns an overall conclusion category to the site that is based on current conditions at the site. Assigning a conclusion category to the site helps health and environmental agencies to prioritize work that is needed at a site. The team assesses the degree of public health hazard based on the following factors:

1. the existence of past, current, or potential future exposures to site-specific contaminants (including radionuclides) or physical or safety hazards,
2. the susceptibility of the potentially exposed population, and
3. The likelihood of exposures resulting in adverse health effects.

The team then assigns a general statement about the health hazards associated with the site for completed exposure pathways (and in some instances potential exposure pathways) and the time period of potential concern. In summary, the team should determine whether conditions:

• Pose a “hazard”
• Pose “no hazard”
• “cannot be fully evaluated” because critical information is missing.

Within this 3-tier framework, ATSDR has five distinct and well-defined categories.

To view a definition of each public health category, click on the terms that follow or on the View All link below.

Category	Definition
Short-Term Exposure, Acute Hazard
Long-Term Exposure, Chronic Hazard
Lack of Data or Information
Exposure, No Harm Expected
No Exposure, No Harm Expected

ATSDR recommends overarching messages that capture the main intended message for each of the 5 categories of hazard.

See the document ATSDR HAZCAT Language for recommended overarching messages and specific examples.