The purpose of this book is to investigate the suitability and applicability of available methods for analyzing the human and ecological risks involved in the release of genetically-modified microorganisms. Main topics include: - risk analysis and assessment; approach to safety assurance; - inventory of available scientific risk assessment methods for biotechnology; - identification of methodology gaps and research needs in biology, ecology or other disciplines; - development of a general framework to guide future biotechnology risk assessment efforts; - international regulatory activities.