Rudolf Engelbrecht, head of working group “Internal Dosimetry”, was invited as renowned expert by Elsevier to contribute the chapter about „Environmental Radioactivity Monitoring” to the 3^rd edition of the „Handbook of Radioactivity Analysis“. Chapter authors from 16 countries will write for the new edition, which will be greatly expanded in scope (from 15 to 21 chapters). The handbook will be the most authoritative and practical reference for university teaching and the research community.