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:
- the existence of past, current, or potential future exposures to site-specific contaminants (including radionuclides) or physical or safety hazards,
- the susceptibility of the potentially exposed population, and
- 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 below.
Short-Term Exposure, Acute Hazard
Applies to sites that have certain physical hazards or evidence of short-term (less than 1 year), site-related exposure to hazardous substances that could result in adverse health effects and require quick intervention to stop people from being exposed.
Long-Term Exposure, Chronic Hazard
Applies to sites that have certain physical hazards or evidence of chronic (more than 1 year), site-related exposure to hazardous substances that could result in adverse health effects.
Lack of Data or Information
Applies to sites where critical information is lacking (missing or has not yet been gathered) to support a judgment regarding the level of public health hazard.
Exposure, No Harm Expected
Applies to sites where exposure to site-related chemicals might have occurred in the past or is still occurring, but the exposures are not at levels likely to cause adverse health effects.
No Exposure, No Harm Expected
Applies to sites where no exposure to site-related hazardous substances exists.
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.
- Page last reviewed: June 14, 2011
- Page last updated: May 31, 2016
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