Category 4: No Apparent Public Health Hazard
This category is used for sites where human exposure to contaminated media may be occurring, may have occurred in the past, and/or may occur in the future, but the exposure is not expected to cause adverse health effects.
This determination represents a professional judgment based on critical data which ATSDR has judged sufficient to support a decision. The assignment of this category does not necessarily imply that the available data are complete; in some cases additional data may be required to confirm or further support the decision made.
Evaluation of available relevant informationb indicates that, under site-specific conditions of exposure, exposures to site-specific contaminants in the past, present, or future are not likely to result in adverse impact to human health.
Category 5: No Public Health Hazard
This category is used for sites that, because of the absence of exposure, do NOT pose a public health hazard.
Sufficient evidence indicates that no human exposures to contaminated media have occurred, no exposures are currently occurring, and exposures are not likely to occur in the future.
aSuch as environmental and demographic data; health outcome data; exposure data; community health concerns information; toxicologic, medical, and epidemiologic data.
bSuch as environmental and demographic data; health outcome data; exposure data; community health concerns information; toxicologic, medical, and epidemiologic data; monitoring and medical management plans. Source: ATSDR 2005.