Brenda Howard (CEH) Historical perspective – previous ICRP guidance Why this has changed - prime motivations International initiatives at the EC, IAEA,

Radiation protection of the environment – an introduction

Brenda Howard (CEH)

www.ceh.ac.uk/PROTECT

Outline Historical perspective – previous ICRP guidance Why this has changed - prime motivations International initiatives at the EC, IAEA, ICRP and

UNSCEAR Comparison with system for humans The situations in which assessments may be used Radiation protection of the environment in the UK Tiered assessments Comparison with chemicals The course

Historical perspective – previous ICRP guidance

“The Commission believes that the standard of environmental control needed to protect man to the degree currently thought desirable will ensure that other species are not put at risk. Occasionally, individual members of non-human species might be harmed, but not to the extent of endangering whole species or creating imbalance between species. At the present time, the Commission concerns itself with mankind’s environment only with regard to the transfer of radionuclides through the environment, since this directly affects the radiological protection of man”

ICRP, 1991, Para. 16

History

Focus on worker/most exposed individuals Incomplete ecological information Limited evidence provided to support

statement (in the context of the environment)

History

Focus on worker/most exposed individuals Incomplete ecological information Limited evidence provided to support

statement Changing attitudes

Late 1990s tools and techniques available Recognition of environmental risks (e.g. Rio) Conservation and protection drivers

History

Focus on worker/most exposed individuals Incomplete ecological information No evidence provided to support statement Changing attitudes

Late 1990s tools and techniques available Recognition of environmental risks (e.g. Rio) Conservation and protection drivers

The need to explicitly demonstra

te no impact…


Drivers

National legislation National interpretation of international

legislation Various bodies – need to explicitly

demonstrate/why different to chemicals IUR promoted need for an approach not

based on humans OECD-NEA has highlighted the need for

radiological assessment of non-human biota and supported tiered assessment approach


Interaction between key international bodies

IAEA

ICRPUNSCEAR

Member States

EU


Radiation Protection and Environment: development

ICRP 1977, 1990 Recommendations If there is compliance with radiation protection standards for

man, other species are not put at risk UNSCEAR (1996)

Report on Effects of Ionizing Radiation to Biota USA, Canadian, EU-Projects (2000-2009)

Scientific base Development of frameworks

IAEA 2005 Setup of the ”Plan of Activities on Protection of the

Environment”

IAEA Safety Fundamentals (2006) Principle 7:Protection of “People and the environment, present

and in the future, must be protected against radiation risks”

ICRP 2007 (Publication 103) Recommendations - the Environment

Recommends the explicit consideration of

Radiological Protection of the Environment

ICRP recognised Need for advice and guidance Lack of consistency at an international level More proactive approach needed Complex nature of environmental protection Need to develop a clearer framework – C5

Assess exposure – dose – effect relationships Pragmatic approach No “dose limits”



ICRP Exposure Situations

Planned - current activities, new nuclear sites and U mines etc Not historic (yrs of discharge)

Mostly for planned NPP and waste repositories (current or prospective discharges)

Existing – exposure to natural radiation sources and contamination of areas by residual radioactive material

Past activities that were never subject to regulatory control or were not

regulated according to present requirements; An emergency, after the emergency exposure situation has been

declared ended Residues from past activities for which there is no longer legally

accountability Used in USA for previously contaminated sites

Emergency – eg accidents, malevolent acts Low priority in acute phase

ICRP Publication 108 (2008)

Provides a Concept and Use of Reference Animals and Plants Transfer, Dosimetry, Effects to biota

=> Derived Consideration Reference Levels Ideas for application

Maintain biological diversity Conservation of species Protect health and status of

Natural habitats Communities Ecosystems

Targets are all related to Living organisms Populations or higher organisational levels Not on individuals (except for endangered species)

Protection of natural resources not included Soil, water, air

Demonstration through a set of Reference Animals and Plants (RAPs)

Protection targets


Planned, Existing and Emergency exposure situations

Environmental radionuclide concentrations

Reference Male & FemaleReference Person

Dose limits, Constraints and Reference levels

Reference Animals and Plants

Derived Consideration Reference Levels

Decision-making regarding public health and environmental protection for the same environmental exposure situation by way of representative individuals and

representative organisms


Human assessment (overview)

RADIONUCLIDE SOURCE

HABITS DATA

REFERENCE PERSON

IMPACT

TOTAL ABSORBED

DOSE

PATHWAY OF EXPOSURE

Application of a weighting factors

for RBE & different tissues

Compare predicted dose to known biological effects & dose limits


Wildlife assessment (overview)

RADIONUCLIDE SOURCE

HABITS DATA

REFERENCE ANIMAL OR

PLANT

IMPACT

TOTAL ABSORBED

DOSE

PATHWAY OF EXPOSURE

Application of a weighting factors

for RBE & different tissues

Compare predicted dose to known biological or

ecological effects & guideline values

ECOLOGICAL PARAMETERS


RAPs



RAP definitionFor human protection, the reference individuals and Reference Person are

idealised models developed for the specific purposes of relating exposure

to dose, and dose to effect.

They do not represent any specific type of human being (the reference

individuals are phantoms, and the Reference Person is a hermaphrodite),

but nevertheless have to be discretely defined to serve their basic purpose.

To be consistent with the original concept of Reference Man, a Reference

Animal or Plant can be described as follows: “A Reference Animal or Plant is a hypothetical entity, with the assumed

basic biological characteristics of a particular type of animal or plant, as

described to the generality of the taxonomic level of family, with defined

anatomical, physiological, and life-history properties, that can be used for

the purposes of relating exposure to dose, and dose to effects, for that type

of living organism.”


UNSCEAR

United Nations Scientific Committee on the Effects of Atomic Radiation

Established in 1955 UN Scientific Committee reports to General Assembly Assesses global levels and effects of ionizing

radiation Provides scientific basis for radiation protection Governments and organisations rely on Committee's

estimates as the scientific basis for evaluating radiation risk and establishing protective measures


UNSCEAR - environment

Report on “Effects of radiation on the Environment” in 1996

Limited available data Review of data, including Chernobyl Based largely on acute data Effects difficult to estimate due to long term

recovery, compensatory behaviour and

confounding environmental factors

New report imminent

UNSCEAR 1996

Acute doses


UNSCEAR draft conclusions

As in its 1996 recommendations, UNSCEAR considers that chronic dose rates of

less than (about) 100 μGy h‑1 to the most highly exposed individuals would be unlikely to have significant effects on most terrestrial communities; and

that maximum dose rates of 400 μGy h‑1 to any individual in aquatic populations of organisms would be unlikely to have any detrimental effect at the population level

nominal Relative Biological Effectiveness (RBEs) of 10 for internally deposited alpha radiation and 1 for beta radiation were recommended

Category Dose rate Effects Endpoint

Plant

100 - 1000 μGy h-1 Reduced trunk growth of pine trees Morbidity

400 -700 μGy h-1 Reduced numbers of herbaceous plants Morbidity

Fish

100 -1000 μGy h-1 Reduction in testis mass and sperm production, lower fecundity, delayed spawning

Reproductive

200 – 499 μGy h-1 Reduced spermatogonia and sperm in tissues Reproductive

Mammals< 100 μGy h-1 No detrimental endpoints have been described Morbidity,

Mortality,Reproductive

Generic ecosystems

(terrestrial and aquatic)

About 80 μGy h-1 A new statistical approach (species sensitivity distribution, SSD) was applied to radiation effects data to estimate the hazardous dose rate (HDR5), the dose rate at which 95% of the species in the ecosystem are protected

Morbidity,Mortality,Reproductive

Overall summary of (illustrative) chronic effects data for plants, fish and mammals

UNSCEAR draft conclusions



”Plan of Activities on Protection of the

Environment” 2005 After Stockholm conference in 2003

IAEA Safety Fundamentals (2006) Principle 7:Protection of “People and the

environment, present and in the future, must

be protected against radiation risks”

Biota Co-ordination Group

Revision of Basic Safety Standards

Approaches Environmental Modelling for Radiation Safety

Application Technical cooperation on wildlife regulation

RER 7005

Revision of the International Basic Safety Standards (BSS), Draft 4.0,

September 2010 Introduction

Protection of people and the environment Prevention of radiological effects on human health and on flora and

fauna. Adopt an integrated perspective to ensure the sustainable use of

natural resources for agriculture, forestry, fisheries and tourism - now and in the future.

Requirements Consider Protection of the Environment

Registration and licensing Setting discharge limits Protection of the environment is one factor during optimization in

existing and emergency exposure situations

=> 3 Safety Guides and 1 Safety Report under development

Radiation Protection of the Public and the Environment (New Safety Guide)

Guidance for the implementation of radiation protection as recommended in the new BSS Exposures to public Exposures to environment

How to apply radiation protection principles to exposures of the environment Justification, Limitation, Optimization

Exposure situations Planned, existing, emergency

Discuss the application of Derived Consideration Reference Levels

=> Input expected from a currently working ICRP Task Group

Radiological Environmental Impact Analysis for Facilities and Activities

(REIA) (New Safety Guide) How to perform a Radiological Environmental Impact Assessment

(REIA) Endpoints Models and methods

Graded approach for the REIA Which efforts are needed for

Small users Hospitals Nuclear installation

How to use already existing data for REIA Data used for assessment of exposures to the public Results from environmental and source monitoring

=> Minimize efforts needed for assessing impacts to biota

Regulatory Control of the Releases of Radioactive Material (Update of a

Safety Guide) Guidance to derive limits for radionuclide discharges to the

environment Public exposure Environmental exposure

Facilities and activities Nuclear installations Laboratories and hospitals Small users NORM

=>Radiological impact to biota will be an integral part of the licensing process


EC Euratom Basic Safety Standards

New BSS outline Title X: Protection of the Environment

Euratom projects FASSET ERICA PROTECT FP7 – STAR Network

CURRENT DRAFT only

Title X: Protection of the Environment

Article 102

Member States shall include, in the legal framework for radiation protection, provision for the radiation protection of non-human species in the environment; this legal framework shall introduce environmental criteria aiming at the protection of populations of vulnerable or representative non-human species with regard to their significance as part of the ecosystem. Where appropriate, practices shall be identified for which regulatory control is warranted to implement the requirements in this legal framework and take account of appropriate environmental assessment criteria

Title X: Protection of the Environment

Article 103Member States' competent authorities, when establishing authorised limits on

discharges of radioactive effluents, in accordance with Article 91 paragraph 2, shall also ensure adequate protection of non-human species; for this purpose a generic screening assessment may be conducted to provide reliance that the environmental criteria are met.

Article 104

Member States shall require undertakings to take appropriate technical measures with the aim to avoid that in the event of an accidental release there will be significant environmental damage, or to mitigate the extent of such consequences.

Article 105

While establishing environmental monitoring programmes, or requiring such programmes to be carried out, Member States' competent authorities shall include representative nonhuman species, if necessary, in addition to such environmental media which constitute a pathway of exposure to members of the public.

Article 31 Group of Experts Recognise that

in line with ICRP Publication 103, is a need for specific consideration of the exposure of biota where appropriate

environmental criteria as well as dose constraints should be considered for the authorisation of discharges of radioactive effluent

Support the development of a framework by ICRP C5

Article 31 Group of Experts Recognise that

in line with ICRP Publication 103, is a need for specific consideration of the exposure of biota where appropriate

environmental criteria as well as dose constraints should be considered for the authorisation of discharges of radioactive effluent

Support the development of RAPS and framework But feel that protection of the environment should not

warrant a high level of regulatory control with demonstration of compliance proportionate to risk and allow enough time for transposition into national law


EC Drivers in the UK Europe: Habitats and Birds

Directives On the conservation of natural

habitats and of wild flora and fauna

UK: Conservation (Natural Habitats) regulations 1994 Implements the Habitats Directive

in the UK. Requires steps to

maintain and restoration to

favourable conservation status of

habitats and species of

Community level interest

Tiered Assessments

Many approaches use a tiered assessment structure (in common with other areas of risk assessments) simple initial screening through to more refined

assessments Also referred to as:

staged or graded approaches


ERICA flow chart

ERICA Integrated Approach

Concentration screening value

Dose rate screening value

Detailed analysis and evaluation of data. Interaction and supplementation with all relevant databases

Extrapolation (e.g. population, ecosystem)

Management Assessment Tool CharacterisationManagement Assessment Tool Characterisation

Tier 3

Site-specific

Probabilistic analysis

Tier 2

Tier 1

Sta

keho

lder

Invo

lvem

ent

Issues

and

options

Plan

Evaluation of assessment

April 2006

Problem formulation

Exit

Exit

Tiered approach

Environmental and health protection

Conservatism

Resources

TIER 1Risk screening

TIER 2Generic quantitative

TIER 3Detailed Quantitative

Data needs

Tiered approach

Environmental and health protection

Conservatism

Resources

TIER 1Risk screening

TIER 2Generic quantitative

TIER 3Detailed Quantitative

Data needs

The level of detail in a ris

k assessment should be proportionate

with the nature and complexity of the ris

k being addressed and

consistent with decision-m

aking needs


Similarities and differences between chemical and radiological risk assessments

Problem Formulation Protection goals common to both approaches and risk assessments are framed in this context.

Exposure Assessment Environmental transfer of contaminants is a common feature but attention to interactions between environment and orgamisms differs (chemical approaches consider factors that affect bioavailability)

Dosimetry A significant feature of radionuclide risk assessment but not chemical assessments. Possible internal and external exposure from radionuclides but only internal residues are relevant for chemicals

Effects Assessment Significant differences: assessment of chemicals is based on empirical ecotoxicological data relating concentrations or daily intakes to effects, whilst assessment of radionuclides uses data that relate effects to dose. Separate assessments are needed for each new chemical, but radionuclide assessments need only consider a limited range of radiation types and qualities

Risk characterisation Similar approaches for characterising risk can be used for both chemicals and radioactive substances

Direct toxicity in soil and water: the assessment of toxicity thresholds for plants, invertebrates and microbial processes

Higher organism health: comparison with•Concentration in food eaten •Ingested amount per unit liveweight of receptor species•Concentration in organs of species compared to a risk quotient

Human health: quantifying exposure to contaminants and assessing acceptable intake values

Approaches for chemicals in the environment

Soil solids Soil water

M-DOM

M-X

M-soil

M output = [M]aq x runoff

M inputg ha-1 a-1

H+

Mz+

Maq

Soil bioavailability

Critical Loads

The critical load is the rate of deposition of a metal from the atmosphere, which at steady

state, leads to the metal concentration in soils or water reaching a threshold for

adverse effects (the critical limit)

Critical Loads for LeadLead

0 - 200

200 - 400

400 - 800

>800

Lead

0 - 200

200 - 400

400 - 800

>800

0 - 200

200 - 400

400 - 800

>800

no exceedance

0 - 10

1 - 20

>20

no exceedance

0 - 10

1 - 20

>20

Critical Load for Pb (g ha-1 y-1)Exceedance of Critical Load for Pb in Managed Broadleaf Woodland

(ratio)


Why are we giving these courses?

Assessments are being done – little formal training available - so we don't assume much prior knowledge

We are being asked for advice on use of assessment tools

The tools are only recently developed and there are various complexities and assumptions which need to be understood


Assessment Tools Three tools freely available and usable by others Focus here on ERICA Tool developed by EC

consortium

RESRAD-BIOTA and R&D 128 mentioned when they have features not present in ERICA Tool

EPICFP4

FASSETFP4

ERICAFP5

PROTECTFP6

Documents

Brenda Howard (CEH) Historical perspective – previous ICRP guidance Why this has changed - prime motivations International initiatives at the EC, IAEA,