[en] This publication represents a sound knowledge base for the conduct of radiotracer studies in the environment, with papers on radiotracer methodology, radiation protection and regulation, data analysis and modelling. Environmental case histories from five Member States - Australia, Brazil, France, the Republic of Korea and Sweden - provide information on conducting studies involving he use of radioactive tracers. These case histories are not meant as guidelines for preparing a field study but can rather serve as examples of the type, caution and extent of work involved in environmental studies using radiotracers. This publication can provide guidance for conducting potential future training events in the use of radioactive traces in the environment and can serve as a key reference to all concerned directly with surface water processes

[en] Radiotracing has enormous potential to provide data to underpin environmental management in aquatic ecosystems. The use of tracer data to validate numerical models, improvements in data acquisition and new tracer forms provide the basis for the future of radiotracing. However, an increasing regulatory burden, reduction in tracer availability and a loss of technical expertise threaten this field of study. Standardisation of tracer approaches where possible and new work on assessing the impact of radiotracers on non-human biota are two areas that may enable the future use of radiotracers at a field scale in engineering and research applications. (author)

[en] The use of artificial radiotracers in the environment is analogous to their use in the human body. In both domains they provide data on flow rates and pathways, on exchange with materials and on their final discharge from the studied system. Artificially injected radiotracers have been used to investigate flow in natural waters since the 1950's. Identification of flow paths, diagnosis of blockages or leakage, measurement of flow rates, dispersion and exchange processes, such as biological uptake or sorption, are all aspects to which a wide range of artificial radioactive tracers have been applied. Increasingly radiotracers are used in combination with numerical modelling to improve confidence in the predictive capacity of models used in the management of our water resources and to extend their spatial applicability. In turn this allows us to use less and less tracer and demonstrate that the human and environmental impact of modern radiotracer studies is minimal. (author)

[en] The translation of raw tracer data into parameters that represent the physico-chemical behaviour of the studied component is a common approach to understand and generalize results from a tracer study. This paper covers aspects of tracer data interpretation including tracer mass balance, travel time distribution, transport parameters, decoupling of tracer and water flows, modelling flow and non-conservative tracers and how to determine model parameters from tracer data. (author)

[en] Case studies are a simple way to demonstrate how radiotracers can be successfully used in the environment in addressing water resources contaminant transport and coastal management issues. This paper presents ten case studies from Korea, France, Brazil, Hong Kong, Australia, Belgium and Sweden using a variety of radiotracers including ^99mTc, ¹⁹⁸Au, ³H, ⁸²Br, ³²P, ^175+181Hf, ¹⁶⁰Tb, ⁵¹Cr(III), ⁶⁵Zn, ⁵⁴Mn and ³⁵S. These studies address physical transport processes such as dispersion and mixing, reactive transport and adsorption and contaminant uptake. Traced components include water, effluent, nutrients, contaminants and mud in rivers, lakes, wetlands and coastal waters. (author)

[en] Methods for the use of radiotracers in aquatic environments have been established over the past five decades. The basic principles involve definition of the system or problem to be investigated, selection of a suitable tracer, design of tracer deployment and measurement systems and analysis of the data collected to address the initial problem. These aspects are covered in detail in this paper covering the current state of the art in tracer technology. New developments in the use of nano-particle tracers are also addressed. (author)

[en] The use of radioactive tracers in the environment is subject to national regulation as well as International Standards and Guidelines. These address aspects of radiation protection during transport, deployment and in the environment following deployment and are relevant not only to radiation workers and members of the public, but also to non-human biota in the receiving environment. This paper outlines the regulatory framework and safety aspects relating to radiotracing and provides examples of radiation doses modeling for humans and non-human biota. (author)