Training course on environmental risk assessment, the ERICA tool and mixture toxicity

Environmental Risk Assessment and on ERICA tool | 2 days

The course will begin by laying the foundations for the assessment of radiation exposure to the environment, describing the global approach to the problem, that is, how sources are characterised, what environmental processes play a role, how environmental concentrations to reference organisms can be predicted from environmental concentrations (transfer), how risks can be calculated and what are the uncertainties associated with different steps in the process. Following from the above, methods for derivation of benchmarks in environmental radiation protection will be described. This part of the course will justify the need for a system to protect the environment from such effects, following a change from the old paradigm "if man is protected, the environment is protected".

After the above we will provide an overview of radiation dosimetry methods for non-human biota. We will start from key concepts such as kerma, absorbed dose, absorbed fraction and dose conversion coefficients for internal and exposure, explaining how they are included in the ERICA tool. Comparison will be made with other approaches. Additionally, we will consider how the tool uses simple models for the transfer of radionuclides from source terms to biological receptors. Justification of the assumptions and simplifications made in the tool by comparison with other models is an important part of this. We will also discuss the limitations of the ERICA tool and some special cases outside ERICA's standard assessment procedure, such as how to assess the environmental impact of gaseous radionuclides.

An important element of this training course will be a series of practical sessions on how to carry out ERICA Tier 1, Tier 2 and Tier 3 impact assessments (including attribution of probability functions for parameter values) for the aquatic and terrestrial environments, with feedback provided after the practical sessions and guidance on what to look for when interpreting an assessment.

Mixture toxicity effects | 1 day

This part of the course will introduce the need of being able to assess the effects of environmental pollutants in a multi‐contaminant context from effects observed in a single stressor situation. The specific issues that should be addressed when dealing with multiple stressors will be explained. Different models developed to predict joint effects of chemical mixtures from single‐chemical toxicity data and to estimate possible deviations indicating synergistic or antagonistic interactions will be introduced. This will be set out as a mixture of lectures, exercises and open discussions. Most emphasis will be Concentration Addition (CA) and Independent Action (IA) models.