dose assessments for wildlife in england & wales

Dose Assessments for Wildlife in England & Wales

Contents

Legislative framework Overview of the assessment framework

Staged approach (1, 2, 3 & 4) Assessing doses to wildlife

Current status

Legislative Framework

Europe: Habitats & Birds Directives On the conservation of natural habitats and of wild flora and fauna

Legislative Framework

Europe: Habitats & 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

The Environment Agency’s Role We have a duty to comply with the EU Birds and Habitats

Directives

The Environment Agency’s Role We have a duty to comply with the EU Birds and Habitats

Directives The Agency’s obligations are to review:

Existing authorisations, consents, licences and permissions for chemicals

All requests for variations to existing or new applications

Ensure that no Agency-authorised activity or permission results in an adverse effect, either directly or indirectly on the integrity of identified European sites (Natura 2000 sites)

The Environment Agency’s Role We have a duty to comply with the EU Birds and Habitats

Directives The Agency’s obligations are to review:

Existing authorisations, consents, licences and permissions for chemicals and radioactive substances

All requests for variations to existing or new applications

Ensure that no Agency-authorised activity or permission results in an adverse effect, either directly or indirectly on the integrity of identified European sites (Natura 2000 sites)

Pressure is from conservation not radiological protection

The Environment Agency’s Role

Given the requirement to assess the impacts of consents and authorisations affecting Natura 2000 sites:

We took the view, based on legal advice and with the support of English Nature (statutory consultee), that these assessments should include ionising radiation

Natura 2000 sites

About 430 Natura 2000 sites in England & Wales

Include Special Areas of Conservation (SAC) and Special Protection Areas (SPA)

Natura 2000 sites

About 430 Natura 2000 sites in England & Wales

Include Special Areas of Conservation (SAC) and Special Protection Areas (SPA)

Note the approach taken aims to be conservative in order to be protective

Timetable

Natura 2000 sites categorised by conservation agencies into:

High priority sites by 2004

Medium priority sites by 2006

Low priority sites by 2008

How does the assessment work?

How does the assessment work?

In stages...

Stage 1

Review of likelihood that discharges from an authorised site could reach a Natura 2000 site

e.g. inland freshwater Natura 2000 site v coastal discharge

Simple rules used authorised aerial discharges within 1km authorised freshwater discharges within 50km

Stage 2

Stage 2

Dose per unit release values calculated for reference organisms (µGy h-1 per TBq) - how?

2001 - R&D 128

R&D 128 provided a:

Review of the latest research on the biological effects of ionising radiation

Simplified approach to determining exposure (through dose calculations) for a set of organisms which were representative of freshwater, marine and terrestrial ecosystems for a limited set of radionuclides

2001 - R&D 128

Radionuclides: 3H, 14C , 32P, 35S, 60Co, 99Tc, 90Sr,

106Ru, 125I, 129I, 131I, 137Cs, 210Po, 226Ra, 234Th, 238U, 239+240Pu, 241Am, 85Kr, 41Ar

Uses concept of “reference” organism

Reference Organism Concept

Key points: (Simplified) geometric shape for dosimetry calculations

Reference Organism Geometries

Reference Organism Concept

Key points: Selected to represent different trophic levels (to enable

transfer of radionuclides to be determined/estimated) Selected to represent different exposure pathways - e.g.

immersed in soil or water, surrounded by air etc. Doses calculated to whole organism

Reference Organisms in R&D 128

Freshwater Estuarine/marine Terrestrial

BacteriaMacrophyte

PhytoplanktonZooplankton

Benthic MolluscSmall BenthicCrustacean

Large BenthicCrustaceanPelagic FishBenthic FishAmphibian

DuckAquatic Mammal

BacteriaMacrophyte

PhytoplanktonZooplankton

Benthic MolluscSmall BenthicCrustacean

Large BenthicCrustaceanPelagic FishBenthic Fish

Fish EggSeabird

SealWhale

BacteriaLichen

Tree, Shrub, HerbSeed

FungusCaterpillar

AntBee

WoodlouseEarthworm

Herbivorous MammalCarnivorous Mammal

RodentBird & Bird Egg

Reptile

Assessment Methodology

REFERENCE ORGANISM

IMPACTIMPACT

Assessment Methodology

ECOLOGICAL PARAMETERS

REFERENCE ORGANISM

RADIONUCLIDE SOURCE

IMPACTIMPACT

PATHWAY OF EXPOSURE

Assessment Methodology

ECOLOGICAL PARAMETERS

REFERENCE ORGANISM

RADIONUCLIDE SOURCE

IMPACTIMPACT

TOTAL ABSORBED

DOSE

PATHWAY OF EXPOSURE

Application of a weighting factor

for RBE

Compare predicted dose to known biological or

ecological effects & guideline values

Simplifying assumptions

External doses calculated from simple infinite or semi-infinite contaminated media formulae, with modifications for self shielding by the organism

Short lived radionuclides assumed to be in secular equilibrium with longer lived parent

Equilibrium between environmental media assumed - so that concentrations in organisms can be estimated from simple concentration factors/ratios

Terrestrial Environment

extitotal

soilisurfacesoil

iitotal

soili

soili DPUCCffDPUCCFCH ,

int, 5.0)(

where:

i

represents summation over all nuclides;

Csoil is the concentration of the radionuclide in surface soil;

CFsoil is the concentration factor for the organism referenced to soil;

fsoil is the fraction of time the organism spends under the soil surface; andfsurface is the fraction of time the organism spends on the ground surface.

2001 - R&D 128

Enter water, air, soil or biota concentrations to calculate dose rates (Gy/h)

Provides advice on practical use of methodology, and states assumptions and constraints

2001 - R&D 128

2001 - R&D 128

Stage 2

Using R&D 128 & some simple dispersion modelling the dose per unit release values were calculated for reference organisms (µGy h-1 per TBq)

Assume discharge at permit limits and impact from combined discharges (air, sewer, river, coastal waters)

Resulting doses compared to screening level of 5 µGy h-1 as agreed with (then) English Nature

Stage 2 - results

Approximately 100 authorisations have been identified that exceed the screening level at 51 Natura 2000 sites & thus require Stage 3 assessment

Stage 2 - results

Approximately 100 authorisations have been identified that exceed the screening level at 51 Natura 2000 sites & thus require Stage 3 assessment Note this is mainly due to choice of analogue

Initial use of other alpha and other beta/gamma categories

Expert judgement may be used to match on half-life and radiation type/energy

Stage 3

Stage 3

Dose per unit release values calculated for reference organisms and feature species and habitats

Threshold of 40 Gy h-1 agreed with English Nature, below which it can be concluded that there will be no adverse effect on habitat site integrity

Feature species & habitats

Feature Species (e.g.): Avocet, Bar-tailed Godwit, Bittern, Black-tailed Godwit, Curlew, Dunlin, Gadwall, Golden plover, Grey plover, Hen Harrier, Knot, Lapwing, Little tern, Marsh Harrier, Oystercatcher, Redshank, Ringed plover, Ruff, Sanderling, Scaup, Shelduck, Snipe, Tufted duck, Wigeon

Feature Habitats (e.g.): Birds of uplands, Birds of lowland heaths and brecks, Birds of lowland freshwaters and their margins, Birds of open sea and offshore rocks, Birds of lowland wet grasslands, Birds of farmland, Birds of coastal habitat, Birds of estuarine habitats

Determine authorisations affecting Natura 2000 site (from

Stage 2)

Obtain Natura 2000 site information

Having identified a feature species, determine

concentration factors and occupancy factors

Determine authorisations affecting Natura 2000 site (from

Stage 2)

Obtain Natura 2000 site information

Having identified a feature species, determine

concentration factors and occupancy factors

Identify any predator/prey for indirect effects

Determine authorisations affecting Natura 2000 site (from

Stage 2)

Obtain Natura 2000 site information

Having identified a feature species, determine

concentration factors and occupancy factors

Identify any predator/prey for indirect effects

Determine which reference organism

geometry can be used to approximate the feature

species geometry

DPUC calculations

Uncertainty typically <10%

Technetium vs. area/volume

y = 1E-09x1.103

R2 = 0.9953

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.E+01 1.E+02 1.E+03 1.E+04area/volume (m-1)

DP

UC

NewtBird

Bat

Caesium vs. area/volume

y = 0.0002x0.0736

R2 = 0.981

1.E-04

1.E-03

1.E+01 1.E+02 1.E+03 1.E+04area/volume (m-1)

DP

UC

NewtBird

Bat

Ecosystem Species Equivalent geometry(R&D Publication 128)

Coastal Avocet, Bar-tailed Godwit, Black-tailed Godwit,Brent Goose, Curlew, Gadwall, Great CrestedGrebe, Gulliemot, Hen Harrier (male andfemale), Kittewake, Lesser Black-backed Gull(male and female), Manx Shearwater, MarshHarrier, Mediterranean Gull, Oystercatcher,Pintail, Puffin, Razorbill, Redshank, RingedPlover, River Lamprey, Sandwich Tern,Shelduck (female), Storm Petrel, Teal, TuftedDuck (female), Turnstone, Wigeon

Benthic Fish

Allis Shad, Atlantic Salmon, Common Scoter,Common Tern, Dunlin, Gannet, Golden Plover,Grey Plover, Knot, Little Tern, Otter (female),Peregrine, Ruff, Sanderling, Sea Lamprey,Shelduck (male), Snipe, Tufted Duck (male),Twaite Shad, White-Fronted Goose

Seabird

Bewicks Swan, Bittern, Chough, Common Seal,Cormorant, Lapwing, Otter (male), Pink-FootedGoose, Scaup, Whooper Swan

Seal

Grey Seal Whale

Ecosystem Species Equivalent geometry(R&D Publication 128)

Coastal Avocet, Bar-tailed Godwit, Black-tailed Godwit,Brent Goose, Curlew, Gadwall, Great CrestedGrebe, Gulliemot, Hen Harrier (male andfemale), Kittewake, Lesser Black-backed Gull(male and female), Manx Shearwater, MarshHarrier, Mediterranean Gull, Oystercatcher,Pintail, Puffin, Razorbill, Redshank, RingedPlover, River Lamprey, Sandwich Tern,Shelduck (female), Storm Petrel, Teal, TuftedDuck (female), Turnstone, Wigeon

Benthic Fish

Allis Shad, Atlantic Salmon, Common Scoter,Common Tern, Dunlin, Gannet, Golden Plover,Grey Plover, Knot, Little Tern, Otter (female),Peregrine, Ruff, Sanderling, Sea Lamprey,Shelduck (male), Snipe, Tufted Duck (male),Twaite Shad, White-Fronted Goose

Seabird

Bewicks Swan, Bittern, Chough, Common Seal,Cormorant, Lapwing, Otter (male), Pink-FootedGoose, Scaup, Whooper Swan

Seal

Grey Seal Whale

Determine authorisations affecting Natura 2000 site (from

Stage 2)

Obtain Natura 2000 site information

Having identified a feature species, determine

concentration factors and occupancy factors

Identify any predator/prey for indirect effects

Determine which reference organism

geometry can be used to approximate the feature

species geometry

Run Assessment

Stage 4

Stage 4

Regulatory action required to reduce the potential impact

Not yet implemented in either chemicals or radioactive substances regulation

Currently the approach is being worked up in consultation with Natural England Need for proportionality, transparency, fairness

Current Status

Timetable - current status

Natura 2000 sites categorised by conservation agencies into:

High priority sites by 2004(completed and reviewed with English Nature in April 04)

Medium priority sites by 2006(completed and reviewed with English Naturein March 06)

Low priority sites by 2008(currently on target)

Current status

All habitat sites to date <40Gy/h, except Ribble Estuary Ribble & Alt Estuary Natura 2000 site assessment is

690Gy h-1 due to Th-234 & short lived alpha emitters discharged from Westinghouse Springfields

Current status

All habitat sites <40Gy/h, except Ribble Estuary Ribble & Alt Estuary Natura 2000 site assessment is

690Gy h-1 due to Th-234 & other short lived alpha emitters discharged from Westinghouse Springfields

Entering Stage 4 of the Habitats Assessment process (Regulatory) Action to be taken by March 2008

Current status

All habitat sites <40Gy/h, except Ribble Estuary Ribble & Alt Estuary Natura 2000 site assessment is

690Gy h-1 due to Th-234 & other short lived alpha emitters discharged from Westinghouse Springfields

Entering Stage 4 of the Habitats Assessment process (Regulatory) Action to be taken by March 2008

What form should this take, what actions should be taken?

Current status

All habitat sites <40Gy/h, except Ribble Estuary Ribble & Alt Estuary Natura 2000 site assessment is

690Gy h-1 due to Th-234 & other short lived alpha emitters discharged from Westinghouse Springfields

Entering Stage 4 of the Habitats Assessment process (Regulatory) Action to be taken by March 2008

What form should this take, what actions should be taken?

However reduction in limits is already planned due to change in operations and recent review of discharges

So…

Discussions have been held with Springfields and the following actions undertaken:

So…

Discussions have been held with Springfields and the following actions undertaken: Review of the data entered into the

spreadsheets

So…

Discussions have been held with Springfields and the following actions undertaken: Review of the data entered into the

spreadsheets Using Springfields environmental data water

concentrations in the Ribble have been modelled (using site specific models)

So…

Discussions have been held with Springfields and the following actions undertaken: Review of the data entered into the

spreadsheets Using Springfields environmental data water

concentrations in the Ribble have been modelled (using site specific models)

Previous levels of discharge identified at the agreed new permit limits and the monitoring data from this period collated

So…

Discussions have been held with Springfields and the following actions undertaken: Review of the data entered into the

spreadsheets Using Springfields environmental data water

concentrations in the Ribble have been modelled (using site specific models)

Previous levels of discharge identified at the agreed new permit limits and the monitoring data from this period collated

Assessment re-run using ERICA tool (part of our move to update R&D128

So…

“Risk of exceeding 40 uGy h-1 is negligible for any species likely to be present in the estuary”

Finally

We are currently reviewing this work Meeting in a weeks time

Finally

We are currently reviewing this work Meeting in a weeks time

Some issues identified E.g. assessment focuses only on radionuclides

discharged from Springfields, may need to consider radionuclides from other sources…

Finally

We are currently reviewing this work Meeting in a weeks time Still planning to undertake a scientific programme

of research in the estuary to identify any potential biological impacts

Finally

We are currently reviewing this work Meeting in a weeks time Still planning to undertake a scientific programme

of research in the estuary to identify any potential biological impacts

Regulatory action required?