Derivation of ATSDR Cancer CVs
CREG = cancer risk evaluation guide
CV = comparison value
CSF = oral cancer slope factor
IUR = inhalation unit risk
This figure shows how ATSDR derives its cancer CVs. ATSDR starts with contaminant-specific cancer risk values. These include health guidelines for chronic ingestion (CSFs) or chronic inhalation (IURs).
ATSDR applies a target risk level of 1 excess cancer in a population of 1 million to the CSFs and IURs.
ATSDR applies default, protective exposure assumptions to the CSFs (such as body weight and intake rate).
This process is how ATSDR derives the contaminant- and media-specific cancer CVs, either the chronic CREGs from the EPA CSFs or the chronic CREGs from the EPA IURs.