I have a copy of EPA's OSWER No. 9200.4-18, signed August 22, 1997. Subject: Establishment of Cleanup Levels for CERCLA Sites with Radioactive Contamination This document presents guidance and applies only to CERCLA sites, the 15 millirem per year EDE is stated as "..should generally be the maximum dose limit for humans...". Does anyone have other references? Claude Wiblin, CHP