Persistent Organic Pollutants in Marine

Ecosystems

Persistent Organic Pollutants

• Fate of PoPs• Mechanisms of Environmental

Control• Characteristics• Main groups• Issues

pcwww.liv.ac.uk/aquabiol/BIOL415_Web/

Tri-Butyl Tin• Nucella• Imposex

HalogenatedAromatic Hydrocarbons

ChlorineBromineFluorine

Types of PoP

• Pesticides• Industrial Chemicals• By-Products

Associated Issues• Bioaccumulation – Biomagnification• Loss of higher predators• Adverse impacts on marine food chains• Fish eating – Gt Lakes of North America,

Baltic & North Sea• Birth defects, reduced aptitude in new

born babies• Endocrine Disruption

Stockholm ConventionUNEP decided to convene an

Intergovernmental Negotiating Committee (INC) to prepare an legally binding instrument

on persistent organic pollutants (POPs).

The INC completed work on the instrument, the Stockholm Convention on Persistent Organic Pollutants, in December 2000.

Stockholm conventionThe Convention entered into force on

17 May 2004. 

The first meeting of the Conference of the Parties took place from 2-6 May 2005 in Punta del Este, Uruguay

http://www.usda.gov/oc/photo/02c2092.jpg

PoPs in Swedish Breast Milk

Toxicity of PoPs• Related to structure• Related to ‘most toxic substance’

– 2,3,7,8 tetrachloro dibenzo dioxin• Toxicity Equivalent - TEQ

– Relative Factor of 1 for 2,3,7,8 TCDD

Dioxins/Furans• 75 individual chlorinated dioxins

• 135 individual chlorinated furans

• Very stable & bind to soils and sediment

DDT• Old problem – Peregrine Falcons

etc• Residues remain• DDE – oxidative environments• DDD – reducing environments• Mersey estuary and Irish Sea

PCBs – Major Problems• Baltic Sea & North Sea• Gt Lakes of North America• Hudson River

• Local “difficulties” :– Mersey Estuary & Liverpool Bay

Poly Chlorinated Biphenyls

• 209 Compounds - ca 100 in env

PCB• Congener 209 –

Deca-choro biphenyl

                                                                

Poly Chlorinated Biphenyls

• 209 Compounds - ca 100 in env• Highly inert• Introduced 1930s• Discovered in environment 1966

by Jensen in Sweden during analysis for DDT

• 750,000 tonnes manufactured

Poly Chlorinated Biphenyls

• Banned by USEPA in new uses in 1979

• Manufacture completely banned in 1984

Poly Chlorinated Biphenyls

• Technical Mixtures

– Arochlor 1242– Arochlor 1254– Arochlor 1262

2000190018000

100

200

300

400

500

600

Total Arochlor W2

Date

Conc(µg/kg)

PCBs

Brominated Fire Retardents

• Poly brominated diphenyl ethers (PBDEs)

• 209 Congeners                                                                 

Brominated FRs• Among the many BFRs used in the world

the main commercial BFRs are the following:

• TBBPA: Tetrabromobisphenol -A 

• HBCD: Hexabromocyclododecane   

• PBB: Polybrominated biphenyls - Phased out in Europe

PBDEs • Deca-BDE (Decabromodiphenyl ether)

  • Octa-BDE (Octabromodiphenyl ether) -

Phased out in Europe 

• Penta-BDE (Pentabromodiphenyl ether) - Phased out in Europe

Flame Retardents

• Polybrominated diphenyl ethers

Other Brominated materials:

• Brominated polymers such as brominated epoxy, brominated polystyrene, brominated polycarbonate, poly (brominated acrylate), and brominated polyols. 

Mersey Estuary• High levels of

BDEs especially : DecaBromoDiphenylEther 209

• On-going research

PoPs: Impacts of tissue residues

Endocrine Disruption

IntersexMerseyMaleFlounder Gonad

Intersex Flounder

Endocrine Disruption

• Molluscs –– TBT - IMPOSEX

Nucella