Diapositiva 1

1
Acute Effects Of Single And Mixed Polycyclic
Aromatic Hydrocarbons Associated To Oil Spills On
The Copepod Oithona Davisae . Carlos Barata1,
Albert Calbet 2, Enric Sainz 2, Laura Ortíz 3,
Josep Maria Bayona 3. 1 Laboratory of
Environmental Chemistry, UPC, Terrassa 2 Dept.
Biologia Marina i Oceanografia, CMIMA, CSIC,
Barcelona 3 Dept of Environmental Chemistry,
IIQAB-CSIC, Barcelona
2
Acknowledgements

• Financial Support
• MEC Spanish project PETROZOO (VEM2003-20037).
• MEC R y C contract to Carlos Barata and Albert
  Calbet

3
Objectives
Develop a modelling framework to predict the
toxicity of mixture combinations of petrogenic
PAHs in copepod species
4
Overview in brief
Effects of crude oil spills in marine planktonic
food webs??? zooplankton species constitute the
major food source for larval fish
5
Overview in brief
Polycyclic aromatic hydrocarbons (PAHs)
6
Methods
Chemicals Naphthalene, 1-methylnaphthalene,
1,2-Dimethylnaphthalene Phenanthrene,1-methylphena
nthrene,3,6-dimethylphenanthrene Fluorene,
Dibenzothiophene, Pyrene Analysis SP -HPLC-UV
Measured variables Lethal , Narcosis after 48 h
()
7
Experimental design
Exposure scenarios
Individual exposures 10 PAHs Mixture
combination of only 9 PAHs using an equitox ratio
Ci EC50j / n n 9 Cj 1/9 TUj
Experimental conditions No food supply,
filtered sea water (38 0/00) 20 oC
8
Data analysis
Modeling responses Allosteric decay function
i
EC


mobile
Mobile
50

control


i
i

PAH
EC
50
Survival
PAHs (mmol/L)
9
Data analysis
Modelling single and mixture toxicities (EC50)
of PAHj
10
Results- Single solutions
Naphthalenes ( mobile vs Control)
Narcosis, survival
N
N1
100
50
0
0
10
20
30
40
0
20
40
60
80
N2
100
50
0
0
5
10
15
PAHs (mmol/L)
11
Results- Single solutions
Phenanthrenes ( mobile vs control)
Narcosis, survival
P
100
50
0
0
3
6
9
P1
100
50
0
0
1
2
3
PAHs (mmol/L)
12
Results- Single solutions
Rest of PAHs ( mobile vs control)
Narcosis, survival
F
DBT
100
50
0
0
2
4
6
8
10
0
2
4
Ft
Py
100
50
0
0.0
0.2
0.4
0.6
0.0
0.3
0.6
0.9
PAHs (mmol/L)
13
Results- QSAR
Narcotization
Survival
Ft
1
0.5
-


5
log
1
K
Log
Py
owj
50
EC
j
1.0
DBT
2.0
N2
P1
EC 50( mmol/L)
P
F
5.0
N1
N
20.0
R2 0.9
60.0
3.0
3.5
4.0
4.5
5.0
5.5
Log K
ow
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Results- Mixtures
Mixture of 9 PAHs at their EC50/9
Survival
Narcotization
125
EC 50 1.1 (0.9-1.3)
100
75
( mobile vs control
50
25
0
0
1
2
3
9
å
EC50
j
Toxic Units 1
9

j
1
15
Conclusions
1. Allosteric decay function predicted accurately
acute responses
2. Acute responses were inversely related to log
Kow QSAR 9 PAH Daphnia magna QSAR gt100 non
polar narcotics
3. Mixture toxicity of PAHs was additive
following the CA model.
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Risk Assessment Implications
Naphthalene
Alkylated Naphthalenes
1000
Highest
100
Prestige
EC 50 (m g/L)
10
1
Background
0.1
1
10
100
1000
Number Mixture components
17
Future Work
2 . How toxicity of real samples (elutriates or
water accommodated fractions of fuel Oil) can be
predicted from Chemical analysis using QSAR models
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Thanks
Environmental Toxicology and Chemistry. Volume
24, No. 11, November 2005.