Radioactivity in the environment, vol 4: Modelling radioactivity in the environment

Abstract

In the preface, the editor—E. Marian Scott of the Department of Statistics of the University of Glasgow— claims that the book summarises the current state of art and science in radioactivity modelling. My impression is that the book in general meets this objective. A total of 13 individual contributions have been included. After an introductory chapter on model design (conceptualisation, evaluation, uncertainty estimates) written by the book editor, the following chapters cover a wide range of subjects, including dispersion of radionuclides in the atmosphere (Mayall), in the oceans (Harms, Karcher & Burchard) and in the geosphere (Russell Alexander, Smith & McKinley). Furthermore, they include the modelling of radionuclide dynamics in agriculturally used terrestrial ecosystems (Pr hl and Crout, Beresford & Sanchez) and in forests (Shaw, Avila, Fesenko, Dvornik & Zhuchenko) and the modelling of radionuclide dispersion and bioaccumulation in lakes and rivers (H kanson & Monte and Sazykina). These contributions are illustrated by case studies that are modelling the hydrodynamic transport of radionuclides in an estuary in South-West Spain (Peri ez & Avril), the dispersion of radionuclides in arctic marine waters (Harms & Karcher), the accumulation of 137Cs by biota in the Chernobyl cooling pond after the reactor accident (Kryshev, Sazykina & Kryshev) and a probabilistic performance assessment of the WIPP nuclear waste disposal site (Helton). Almost inevitably with so many authors contributing, the level of details varies considerably. While some of the chapters focus on discussing the basic physical, biological, chemical processes and their model conceptions, others offer a lot of details on how the (or often, their own) model is built, and numerical values of model parameters are provided. Unfortunately, the scene set by the book editor in her introductory chapter by elucidating the essential steps in any model building process (conceptualization, parameter estimation, model evaluation and estimation of prediction uncertainties) is mirrored to only a limited degree in the various contributions. As a consequence, I suspect it might become difficult for a non-specialist to judge the scientific value of some of the modelling approaches that are presented. In addition, it should have been possible by some more careful editing done by the publisher to update those 1997 references that are cited as “to appear” or “in press”. Are there substantial areas of modelling radioactivity in the environment missing? Although the editor has done a great job to include a wide variety of subjects, my answer to this question is: yes, there are at least two areas of increasing importance in modelling radionuclide behaviour in the environment which I guess should be discussed in a compendium like this. First, spatial variability is of primary importance at least in terrestrial radioecology and a contribution addressing classical stochastic approaches as well as geostatistic modelling concepts would have been desirable. Second, the mobility and bioavailability of a radionuclide in soils, sediments and fluids often depends crucially on its chemical species, but unfortunately no reference is made throughout the book to speciation models and their results. Despite these limitations, the book gives a summary of the state-of-the-art in modelling the dynamics of radionuclides in the environment and, therefore, is highly recommended for regulators, researchers and students who are active in this field. However, those who are interested in environmental processes of other toxic substances may also benefit from the compendium of modelling approaches presented in this book.