Upload
jamie-cade
View
216
Download
0
Tags:
Embed Size (px)
Citation preview
Radiation protection of the environment - International context
Centre for Ecology & Hydrology - Lancaster 27th – 29th June 2012
www.ceh.ac.uk/PROTECT
Outline
Historical perspective of environmental radiological protection
Why this has changed - prime motivations International initiatives in key international
bodies The UK perspective Comparison with chemicals
‘Although the principal objective of radiation protection is the achievement and maintenance of appropriately safe conditions for activities involving human exposure, the level of safety required for the protection of all human individuals is thought likely to be adequate to protect other species, although not necessarily individual members of those species. The Commission therefore believes that if man is adequately protected then other living things are also likely to be sufficiently protected.’
ICRP, 1977
The ICRP statements
The ICRP statements
“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.
ICRP, 1991
www.ceh.ac.uk/PROTECT
Whats the issue?
Human radiological protection: Focus on worker/most exposed
individual Environment more as a route for
transfer to humans Incomplete ecological information What’s the protection goal? Evidence needed for or against
ICRP statement
Lack of demonstration that the environment is being protected
May not be valid for some environments (e.g. those with no humans)
Incompatible with management of other environmental chemical stressors
Requirement for assessment under some national legislation
Challenges to anthropogenic approach
www.ceh.ac.uk/PROTECT
Interaction between key international bodies
IAEA
ICRPUNSCEAR
Member States
EU
recommendationsevidence provision
establishing standards
www.ceh.ac.uk/PROTECT
Chronology
ICRP 1977 – statement appears ICRP 1991 – recognise individuals may be impacted ICRP 2007 – Recommendations include need to consider
environment and introduces ‘RAP Framework’
UNSCEAR (1996, 2011) Reports on Effects of Ionizing Radiation to Biota
USA, Canadian, EU-Projects (2000-2009) Scientific basis developed Development of frameworks
IAEA (2005) 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”
www.ceh.ac.uk/PROTECT
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”
www.ceh.ac.uk/PROTECT
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)
Demonstration through a set of Reference Animals and Plants (RAPs)
Protection targets
Planned, Existing and Emergency exposure situations
Environmental radionuclide concentrations
Reference Male & Female
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 using representative individuals and
representative organisms
www.ceh.ac.uk/PROTECT
www.ceh.ac.uk/PROTECT
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
www.ceh.ac.uk/PROTECT
Wildlife assessment (overview)
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
RADIONUCLIDE SOURCE
ECOLOGICAL PARAMETERS
www.ceh.ac.uk/PROTECT
ICRP 108 - RAPsFor 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.”
www.ceh.ac.uk/PROTECT
RAPs•Considers 12 RAPs (adult life stages) and 39 elements•RAPs defined at taxonomic level of Family
www.ceh.ac.uk/PROTECT
Recent/ongoing ICRP work ICRP, 2003. A Framework for Assessing the Impact of
Ionising Radiation on Non-human Species. ICRP Publication 91. Ann. ICRP 33 (3).
ICRP, 2008. Environmental Protection - the Concept and Use of Reference Animals and Plants. ICRP Publication 108. Ann. ICRP 38 (4-6).
ICRP, 2009. Environmental Protection: Transfer Parameters for Reference Animals and Plants. ICRP Publication 114. Ann. ICRP 39 (6).
www.ceh.ac.uk/PROTECT
Ongoing ICRP focus
Task groups on Relative Biological Effectiveness More realistic dosimetry for non-human species Integrating the ICRP System of Protection for
humans and non-human species Forthcoming reports
The ICRP's approach to protection of the environment under different exposure situations
The Practical Application of Reference Animals and Plants to Different Exposure Situations
www.ceh.ac.uk/PROTECT
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
www.ceh.ac.uk/PROTECT
UNSCEAR 2011 conclusions
As in its 1996 recommendations, UNSCEAR considers that chronic dose rates of
less than 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
UNSCEAR 2011 conclusions
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
www.ceh.ac.uk/PROTECT
www.ceh.ac.uk/PROTECT
Biota Co-ordination Group
Revision of Basic Safety Standards
Approaches Environmental Modelling for Radiation
Safety
Application Technical cooperation on wildlife
regulation RER 7005
Plan of Activities on Protection of the Environment 2005
IAEA Safety Fundamentals (2006)
www.ceh.ac.uk/PROTECT
Safety objective is:
“The fundamental safety objective is to protect
people and the environment from harmful
effects of ionizing radiation”
www.ceh.ac.uk/PROTECT
IAEA Fundamental Safety Principles
Principle 7 Protection of present and future generations People and the environment, present and future,
must be protected against radiation risks
Environment = Ecosystems and populations
Objectives Prevention of radiological effects
on flora and fauna Man is an integral part of the
environment Ensure the sustainable use of
natural resources now and in the future
Agriculture Forestry Fisheries Tourism
Basic Safety Standards
www.ceh.ac.uk/PROTECT
Requirements Consider Protection of the Environment
Registration and licensing Setting discharge limits Monitoring Remediation
Protection of the environment is one factor during optimization in existing and emergency exposure situations
=> Associated Safety Guides and Safety Report under development
Basic Safety Standards
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 from 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 installations
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
www.ceh.ac.uk/PROTECT
EC Euratom Basic Safety Standards
on 29 September 2011 the European Commission adopted the Proposal for a Council Directive laying down basic safety standards for protection against the dangers arising from exposure to ionising radiation [COM(2011)593].
Euratom projects FASSET ERICA PROTECT FP7 – STAR Network
CURRENTLY STILL DISCUSSING
www.ceh.ac.uk/PROTECT
Other 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 Directive in the
UK.
The UK has interpreted the EC Birds & Habitats Directives as requiring assessments to determine that no authorised discharges of radioactivity will impact upon protected (Natura 2000) sites.
US DOE facilities are required to demonstrate annually that routine radioactive release from their sites are protective of non-human receptors
DOE Order 5400.5: In addition to providing protection to members of the public, it is DOE’s objective to protect the environment from radioactive contamination to the extent practical.
Assessed against dose rate limits for different organism groups established to avoid measurable impairment of reproductive capacityObjective: to protect the terrestrial and aquatic environment, including populations of animals and plants within and beyond the boundaries of DOE sites ……
USDOE
www.ceh.ac.uk/PROTECT
Differences between chemical and radiological risk assessments
Exposure Assessment
Chemical approaches often consider factors that affect bioavailability
Dosimetry Needed for radionuclide but not chemical risk assessments.
Possible internal and external exposure from radionuclides but only internal relevant for chemicals
Effects Assessment
Assessment of chemicals is based on empirical ecotoxicological data relating concentrations or daily intakes to effects
Assessment of radionuclides uses data that relate effects to dose.
Separate assessments are needed for each chemical
Radionuclide assessments need only consider a limited range of radiation types and qualities
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
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
Some examples of assessments being conducted
Sweden, UK, Canada & Finland – waste repositories
England & Wales >700 authorisations impacting on (protected) Natura 2000 sites
USDOE sites – assessment is an annual requirement
U industry – (e.g. Canada, Australia) New build power plants (e.g. UK) Decommissioning (e.g. Lithuania)