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Title: Pr sentation PowerPoint Author: nbodin Last modified by: mjtheb Created Date: 7/23/2004 12:03:33 PM Document presentation format: Affichage l' cran – PowerPoint PPT presentation

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Title: Pr


1
PCBs, PCDD/Fs AND PBDEs IN SPIDER CRABS
COMPARISON WITH MUSSEL AND SEA BASS
CONTAMINATION
N. Bodin, A. Abarnou, A-M. Le Guellec
Département Biogéochimie et Ecotoxicologie,
IFREMER, Centre de Brest - BP70 - 29280 Plouzané,
France Nathalie.Bodin_at_ifremer.fr
  • Objectives
  • PCBs, PCDD/Fs and PBDEs are very persistent and
    toxic pollutants for marine organisms and humans.
    However, very little information is available on
    the presence of these compounds in exploited
    decapod crustaceans from the French waters. This
    study allowed
  • to obtain first data on PCB, PCDD/F and PBDE
    levels and distribution in the spider crab Maja
    brachydactyla. This crustacean species was chosen
    because of its important commercial interest in
    certain French regions like Brittany and
    Normandy.
  • to contribute to a better understanding of the
    factors acting on the distribution of these
    contaminants in crustaceans. For that purpose,
    spider crab contamination was compared to that of
    mussels, considered as good indicators of marine
    pollution, and that of sea basses, because fishes
    are known to be able to biotransform some
    contaminants.
  • Sampling and analysis
  • Spider crabs were collected in February 2003 on
    five sampling areas Antifer (Seine Bay) where
    RNO measured the highest PCB levels in mussels
    since 70s, and the others along the Brittany and
    Normandy coasts which are very little
    contaminated by such man-made compounds.
  • Mussels Mytilus edulis and sea basses
    Dicentrarchus labrax were collected at Antifer
    (Seine Bay) in February 2003.
  • For spider crabs and sea basses, analyses were
    performed on muscle for mussels, the whole soft
    body were analysed.
  • ? The 17 toxic 2378-substituted PCDD/Fs, 7
    indicator PCBs, 12 dioxin-like PCBs and 13 PBDEs
    were analysed by high resolution GC-MS.

Spider crab contamination
  • PCDD/Fs
  • ? At Antifer, PCDFs represent 75 of ?17PCDD/Fs,
    oppositely to other sites (PCDFs 40-45).
  • ? In all cases, OCDD (D7) and 1234678-HpCDD (D6)
    are prevalent among PCDDs. For PCDFs, 2378-TCDF
    (F1) and 23478-PeCDF (F3) are main compounds.
  • ? All contaminants present higher levels in
    specimen from Antifer which confirms a chronic
    pollution of the whole Seine Bay mainly due to
    contaminant inputs by the Seine River.
  • PCB concentrations measured at Antifer are 6 to
    20 higher than those from the other sites. For
    PCDD/Fs and PBDEs, they exceed only by a factor 3
    to 5.
  • Total TEQ varies from 0.7 (Granville) to 6.8
    (Antifer). Moreover, the contribution of DL-PCBs
    to the Total TEQ is nearly 2 times higher in
    crustaceans than that of PCDD/Fs.

? PCBs and PBDEs
  • Similar patterns are observed whatever the site
    and the contamination level.
  • For PCBs, main compounds are CB153gt
    CB118gtCB180gtCB138.
  • For PBDEs, major congeners are BDE47gt
    BDE99gtBDE100gtBDE28.

X/BDE47100
Contamination comparison between organisms
The comparison of contamination of three species
(mussel, spider crab and sea bass) collected in
the same period and area (February at Antifer)
allowed to evaluate the influence of biological
factors on the distribution of PCB, PCDD/F, and
PBDE. These three organisms were selected because
of their different trophic level, feeding mode
and metabolisation capacities.
PBDEs
PCBs
X/BDE47100
PCDD/Fs
  • CB153 is always the main congener in all samples
    and represents 40-50 of ?18PCBs.
  • Mussels and sea basses show similar PCB patterns
    with predominance of CB153, CB101, CB118 and
    CB138. However, different levels of CB180 are
    observed due to the different feeding mode of
    these species.
  • For spider crabs, the main congeners are the
    CB118 and CB180. The slight presence of CB52,
    CB101 and CB138 compared to mussels argue for the
    biotransformation of these compounds by spider
    crab.
  • BDE47 is the main compound in all samples. For
    mussels and spider crabs, it represents 60 of
    ?13PBDEs, against 80 in sea basses.
  • The other major congeners are the BDE28, BDE99,
    BDE100, BDE153, BDE154, BDE183.
  • The BDE99 can theoretically be metabolised in
    BDE47 by debromination processes. The profiles
    show that sea basses have greater metabolisation
    capacities than crustaceans, and the last ones
    higher than mussels for this congener.
  • Very different dioxin patterns are observed
    between the three species. In mussels, PCDDs (60
    of ?17PCDD/Fs) gt PCDFs, oppositely to spider
    crabs and sea basses (PCDDs 25 of ?17PCDD/Fs).
  • As well greater levels of highly toxic congeners
    (2378-TCDF (F1), 23478-PeCDF (F3)), as lower
    concentrations of OCDD (D7) in spider crabs and
    sea basses suggested the enzyme induction in
    these species compared to mussels.

Conclusion ? The highest contaminant levels
in spider crab muscle were measured at Antifer
(Seine Bay). However, even those do not raise any
sanitary problems based on the fixed TDI for
PCDD/Fs and DL-PCBs at 2.33 pg TEQ.kg-1b.w. per
day (JECFA, 2002), and for 7 indicator PCBs at
0.01 µg. kg-1b.w. per day (AFSSA, 2003). ?
The PCB and PBDE distributions are
species-dependant (influence of trophic level,
feeding mode and metabolisation capacities), and
are not related with the geographical situation
and contamination levels. ? PCDD/F patterns
are also species-dependant, although differences
were observed in spider crabs from Antifer and
the other sampling areas. The very important PCB
levels measured at Antifer and the possible
traces of PCDFs in technical PCB mixtures, could
increase their concentrations in the environment
but also modify their distribution in the biota.
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