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Assessing effects of metals to freshwater and marine systemsKatrien Delbeke
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Setting environmental quality standards … the Water Framework Directive ….
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EU Water Framework DirectivePrinciples for compliance checking
CHEMICAL STATUS
Annex X + 8 other pollutants (EQS)
Pass
Background
Fail
Biological quality
Physico-chemical quality
Annex VIII pollutants (EQS)
Pass/fail
High
Good
Mod
Poor
Bad
Ecology
Chemical
Lowest
ECOLOGICAL STATUS
Lowest
Pass/fail
Lowest
CLASSIFICATION
EC EQS guidance
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Environmental compartmentWater Sediment Biota
Receptor(s) at risk
Humans X (consumption of
fish products)
Benthic biota X X
Pelagic biota X (secondary poisoning)
Top predators
(birds, mammals)
X (secondary poisoning)
Setting environmental quality standards (EC EQS guidance and Norway EQS proposal)
EC EQS guidance
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EU Water Framework Directive Setting environmental quality standards (EQS)
Some important documents
- Common Implementation Strategy for the Water Framework Directive
(2000/60/EC) - Guidance Document No. 27: Technical Guidance For
Deriving Environmental Quality Standards Technical Report - 2011 –
055 …..= EC EQS guidance
- Draft Norwegian background document on environmental quality
standards (Feb 2013) ….= Norway EQS proposal
- Questions/Comments submitted by industry on the Norwegian
…= industry comments
- REACH dossiers submitted to ECHA
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Metal- specific characteristics- Metals are naturally occurring … varying background
- Some metals are essential
… Organisms have adapted mechanisms to cope against variability in
metal concentrations (regulated uptake/elimination; internal binding)
… Bioconcentration factors are NOT constant but depending on
background values = Biota standard NOT relevant for Cu/Zn
- Metals/metal compounds toxicity driven by Me-ions.
… NOT Total or dissolved metals BUT Bio-availability of metal ions
… Metal ions need to be released from sparingly soluble metal
materials (eg ore bodies, slags, tailing) to be bio-available
Setting environmental quality standards
(EC EQS guidance and industry comments to Norway EQS proposal
EC EQS guidance
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Metal Freshwater AA EQS (µg/l)
remarks
Hg and its compounds 0.05 Consider also biota
Cd and its compounds ≤ 0.08 If hardness < 40mg CaCO3/l
0.08 H: 40 - ≤ 50
0.09 H: 50 - ≤ 100
0.15 H: 100 - ≤ 200
0.25 H: ≥ 200
0.20 generic
Pb and its compounds 1.2 bio-available directive 2013/39/EU
Ni and its compounds 4 bio-available directive 2013/39/EU
Environmental quality standards for EU priority substances
(EC EQS guidance -12 August 2013)
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Norway EQS setting – background document …industry assessment…
Risk assessment data used
Statistical evaluation for data-rich assessments used
Missing : metal-specific aspects of the EC EQS guidanceo Incorporation of bio-availability into the compliance settingo Incorporating background levels into the compliance setting
Missing : Reach updates o Copper and zinc marine mesocosm study = now from REACH
Uncertainty around Sediment EQSo Freshwater versus marine partitioning coefficient (Kd) values…?
How the different classes were assigned….
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Setting a Freshwater EQS
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Setting environmental quality standards (Metal- specific EC EQS guidance)
Bio-availability models available?(BLM, regression, speciation)
Evaluate/compile ecotox data. If possible, express data on dissolved basis (water) or dry weight basis (sediment)
Is between-species extrapolation possible?
STEP 2 - full bioavailability correctionQS reference
STEP 2- baseline bioavailability correction
QS genericBio-availability correction – option 2 – BioF approach
Is the QS reference < background level?
Keep TRA - no background correction QS generic or QS reference, TRA
STEP 3 - use ARA – Background correctionQS generic or QS reference, ARA
Keep QS generic
No bio-availability correction – option 1
no
yes
yesno
yesno
STEP 1 : Generate a QS generic
Bio-availability correction – option 2 or 3
Step 1 : Generic EQS
Step 2: Bio-availability
Step 3 : Background
Norway- EQS application
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Importance of bioavailability - freshwater
Factor 30 difference EC50 D. magna
same species, same strain, different waters
0
100
200
300
400
01 02 03 05 06 07 07 08 09 10 11
48
h-E
C5
0 in
µg
Cu/
L
648
Evidence on site-specific toxicity for Cd, Ni, Pb, Cu, Zn, ….related to DOC, pH, Ca, Na, ….
Can we quantify the bio-availability effect?
0
100
200
300
400
500
600
1 2 3 4 5 6 7 8
Location
NO
EC
(µg
Zn/L
)
Bioavailability – freshwater
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Predict Metal bio-availability - freshwaterThe BIOTIC LIGAND MODEL for fish & invertebrates
Cu2+DOCToxicity
Inorganic complexes (E.g. carbonates, hydroxides)
CaMgNaH
2+
2+
+
+
Competition
Organic complexes
toxic action or transport sites
= biotic ligand
(BL)
Cu2+
organism-water interface
Gill Site Interaction Model(Pagenkopf, 1983)
WHAM(Tipping, 1994)
Cu2+
Toxicity
Di Toro et al., 2001 Bioavailability – freshwater
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Validation of bio-availability models - Freshwater (Metal- specific EC EQS guidance)
10
100
1000
10000
10 100 1000 10000
observed EC50 (µg/L)
pre
dic
ted
EC
50 (
µg
/L) Daphnia - acute - Cu
Daphnia - chronic -Cu
Daphnia -acute -Zn
Daphnia - chronic -Zn
Daphnia - acute - Ni
Field cladocerans -acute - CuRainbow trout -chronic - Zn
Metal pH Ca, mg L-1 DOC, mg L-1
Cu 6.0-8.5 3.1-93 (160) UnlimitedNi 6.5-8.2 (8.7) 3.8-88 UnlimitedZn 6.0-8. 2 (8.5) 5.0-160 Unlimited
Boundaries for the Biotic Ligand Model (BLM)
BLM applications to chronic freshwater EQS
Site-specific Cu EQSIf info on pH, DOC and
hardness
User-friendly tool : http://bio-met.net
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Bioavailability – freshwater
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Conclusion long term water EQS values Cu and Zn examples
AA- EQS freshwater
Norway EQS proposal
Comment
Cu 7.8 7.8+ Bio-availability correction (BLM)
Zn 10.9 10.9+Bio-availability correction (BLM)Background correction
Bio-availability : BLM
Background correction
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Setting the marine EQS
Marine EQS setting
Zinc
- NOECS for >40 species
- marine mesocosm = NEW
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Copper
-NOECs for 24 species
- marine mesocosm =NEW
- bio-availability correction
Marine EQS
Marine bio-availability correction(Metal- specific EC EQS guidance)
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Freshwater and marine organisms face very different iono- and osmoregulatory issues related to living in either a very dilute or concentrated salt environment. = freshwater BLMs can NOT be used for marine environments
Marine fish do also suffer from osmoregulatory disturbances under metal exposure and, therefore, similar toxicity mechanisms may apply
= assess marine bio-availabilty corrections
Marine EQS- bioavailability
Scientific evidence for marine bio-availability correction
…copper example
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1
10
100
0.1 1 10
(active) Dissolved Organic Carbon (mg/l)
No
rma
lise
d E
C5
0 (
μg
/l)
Fucus vesiculosis
Crassostreas gigas
M. galloprivincialis
Mytilus edulis
D. excentricus
S. purpuratus
y = 16.715x0.6136
R2 = 0.7662
Marine EQS- bioavailability
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Conclusion long term water EQS values Cu and Zn examples
AA- EQS marine water
Norway EQS proposal
Comment
Cu 2.6 5.2 + Mesocoms study+ DOC correction
Zn 3.4 6.9+ Mesocoms study+ background correction
New research data : mesocosm
Bio-availability : OC correction
Background correction
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Setting the sediment EQS
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Sediment EQS setting (Metal- specific EC EQS guidance
1. Freshwater EQS and Kd values…copper example
- Freshwater suspended matter 30,246 l/kg
- Estuarine suspended matter 56,234 l/kg
- marine suspended matter 131,826 l/kg
2. Sediment EQS and SSD …. zinc example
- Updated data-set – sediment toxicity
- Kd zinc under revision
Sediment bio-availability(Metal- specific EC EQS guidance)
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Sediment bioavailability corrections :
- Organic carbon normalization (cfr organic substances)- Insoluble MeS are formed in anaerobic conditions =
correction for metal-sulfides, measured as “Metals bound to Acid Volatile Sulfides -AVS”
for Zn, Cd, Pb, Cu, Ag, Hg Metal sulphide solubility products Log K(a) Log K(b)
MnS (s) -19.15 - 13.50
(amorphic) -21.80 -
(s) -22.39 -18.10
(s) -27.98 -
ZnS (s) -28.39 -24.70
CdS (s) -32.85 -27.00
PbS (s) -33.42 -27.50
CuS (s) -40.94 -36.10
Ag2S (s) -50.10
HgS -57.25 -52.70 Bioavailability – sediments
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Conclusion sediment EQS values Cu and Zn examples
EQS freshwater sediments EQS marine sediments
EQS Norway proposal
Comment EQS Comment
Cu 210 87+SSD and Bio-availability correction : OC and AVS
84 676+Mesocosm, Kd marine and Bio-availability correction : OC and AVS
Zn 139 147+Updated data-setBio-availability correction : OC and AVS
340 159+Mesocosm, Kd marine and Bio-availability correction : OC and AVS
Revised databases; Kd value marine; Bio-availability : OC and AVS Background correction
Summary and conclusions
Thanks
Most up to data information needed for WFD compliance checking
Bio-availability is important to reduce uncertainty
Evidence to be provided
• by metal
• by species
• by compartment
Practically
• Freshwater : http://bio-met.net
• Marine water : DOC
• Sediment : OC and AVS
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1. Comparison with generic EQS
2. Use of screening tool
3. Consideration of local ambient background concentrations
4. Remedial measures
Pass
Pass
Pass
2. Use of user-friendly BLM
EXCEEDANCE
EXCEEDANCE
EXCEEDANCE
No further action necessary
Prog
ram
mes
of
mea
sure
sCl
assifi
catio
n
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THANKS
For more information, please contact
Katrien. delbeke@copperalliance .eu
