Radioactive sources such as nuclear power installations can pose a great threat to both humans and our environment. How do we measure, model and regulate such threats? Environmental Radioactivity and Emergency Preparedness addresses these topical questions and aims to plug the gap in the lack of comprehensive literature in this field. The book explores how to deal with the threats posed by different radiological sources, including those that are lost or hidden, and the issues posed by the use of such sources. It presents measurement methods and approaches to model and quantify the extent of threat, and also presents strategies for emergency preparedness, such as strategies for first-responders and radiological triage in case an accident should happen. Containing the latest recommendations and procedures from bodies such as the IAEA, this book is an essential reference for both students and academicians studying radiation safety, as well as for radiation protection experts in public bodies or in the industry.