Persistent Organic Pollutants in Marine

Ecosystems

PoPs in Swedish Breast Milk

HalogenatedAromatic Hydrocarbons

ChlorineBromineFluorine

Types of PoP

• Pesticides• Industrial Chemicals• By-Products

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

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

pcwww.liv.ac.uk/aquabiol/BIOL202_Web/

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• 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

Flame Retardents

• Polybrominated diphenyl ethers

Impacts of tissue residues

Endocrine Disruption

Intersex

Mersey

Male

Flounder

Gonad

Intersex Flounder

Endocrine Disruption

• Molluscs –– TBT - IMPOSEX

Nucella