Typical sediment contaminants

Distribution of contaminants surface waters between water, air and sediments/suspended matter according to partitioning coefficients.

High lipophilicity (octanol/water partitioning coefficients kOW) and low volatility from water (Henry coefficient) support accumulation in sediments and suspended matter.

Typical sediment contaminantsPolycyclic aromatic hydrocarbons (PAHs)Class of organic pollutants with two or more condensed aromatic rings

fluorenenaphthalene anthracene phenanthrene pyrene fluoranthene

chrysenebenz[a]anthrace benzo[a]pyrene benzo[e]pyrene perylene

benzo[k]fluorantheneindeno[1,2,3-cd]pyrene

benzo[ghi]perylene

Examples

+ methyl and ethyl derviatives

coronene

Typical sediment contaminantsPolycyclic aromatic hydrocarbons (PAHs)Properties:•lipophilic: log kOW: 3.3 (naphthalene) to 7.6 (coronene) and higher •water solubility low: 30 mg/L (naphthalene) to 0.00014 mg/L (coronene)•many PAHs genotoxic, mutagenic and carcinogenic (most of them after enzymatic activation (indirect mutagens)•always occurring in mixtures of hundreds of compounds

Major sourcespyrogenic (incomplete combustion)petrogenic (handling of coal and petroleum)

coal coking (blowing off volatiles at 2000°C)

Typical sediment contaminantsPolycyclic aromatic hydrocarbons (PAHs)

Major sources aluminium production (coal anodes) domestic

heating

motor vehicle traffic forest fires

coal-fired power plants

Incineration of refuse

Typical sediment contaminantsHalogenated aromatic hydrocarbons

Polychlorinated biphenyls (PCBs)

ClxCly

used in/as transformers, capacitors, hydraulic fluids, flame retardants…….

Properties:•209 Congeners. Commercial products (e.g. Aroclors) are mixtures of 50 or more.•Viscous liquids•High dielectric constants, high thermal conductivity, high flash point•very resistant to oxidation, reduction, addition, elimination and electrophilic substitution ⇒ very persistent•produced in the U.S. since 1929 (later also in Europe, Japan, USSR)

Typical sediment contaminantsPolychlorinated biphenyls (PCBs)

Properties:•highly lipophilic (log KOW 4.6 to > 8)•low water solubility (2 mg/L (MCB) to 10-6 mg/L (DCB)•bioaccumulating•globally distributed •high concentration in the arctic (global distillation), accumnulation in polar bears, seals… ⇒ hazard for ecosystem and human health

Typical sediment contaminantsPolychlorinated biphenyls (PCBs)

Toxic/ecotoxic effects

1968 mass poisoning in Japan with PCB contaminated rice bran oil ⇒ Yusho Disease in over 14,000 people

Particularly the co-planar PCB congeners are highly toxic to humans and animals (dioxin-like toxicity)

Toxicity to humans: Chloracne, liver damage, dermal and ocular lesions, lowered immune response, carcinogenicity, poor cognitive development of children.

Typical sediment contaminantsPolychlorinated biphenyls (PCBs)

Toxicity to animals:

Acute effects: Liver damage and death (e.g. 400,000 birds 1968 in Japan after feeding on PCB contaminated poultry feed)

At smaller concentrations effects on immune system, behavioral alterations, impaired reproduction).

Particularly severe: accumulation in and effects on top predators like the white tailed see eagle. Clutch of 2 dead eggs in a

white-tailed sea eagle nest

Accumulation in aquatic food webs from sediments via invertebrates and fish to top predators (biomagnification)

Typical sediment contaminantsPolychlorinated biphenyls (PCBs)

Several large scale environmental contamination incidents

U.S. New York State: 1947 to 1977 release of 590 tons of PCBs by a capacitor manufacturing plant. Very high levels in fish ⇒ ban of all fishingMultiple remediation activities still going on

U.S. Dumping of reject capacitors and PCB oils down drains of Westinghouse Electric (Bloomfield, Indiana). Contamination of sewage treatment plant. Sludge was used for farms and gardens.

Typical sediment contaminantsHalogenated aromatic hydrocarbons

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs)

O

O

Cl

Cl

Cl

ClO

Cl

ClCl

Cl

Most toxic representatives of dioxin-like toxicity (see PCBs)

Very persistent

Byproduct of organic synthesis of halogenated aromatic compounds and incineration processes

2,3,7,8-TCDD 2,3,7,8-TCDF

Seveso accident 1976:Explosion in factory producing 2,4,5-trichlorophenolEmission of 1 to 3 kg 2,3,7,8-TCDD3300 animals domestic animals died at once, 80.000 very slaughtered200 severe cases of cloracne Pregnant women were advised to abort

Latest victim of PCDD/Fs:

Typical sediment contaminantsHalogenated aromatic hydrocarbons

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs)

Agent orange (2,4,5-Trichlorophenoxyacetic acid and 2,4- Dichlorophenoxy-acetic acid) contaminated with 2,3,7,8-TCDD applied by U.S. American troops in 1961-1971 against Vietnam

Still 500.000 citizens suffer from remote damages due to TCDD (cancer, malformations……)

Typical sediment contaminantsHalogenated aromatic hydrocarbons

Polychlorinated naphthalenes (PCNs) Cl

Cl

Cl

ClSources:•technical products (e.g. Halowax) mainly used in electrical industry•byproducts of industrial processes (e.g. chloralkali electrolysis –binders of graphit electrodes)•incineration processes (fly ash)

Dioxin-like acting planar halogenated aromatic hydrocarbonsVery lipohilic and persistent

Typical sediment contaminantsHalogenated aromatic hydrocarbons

Polybrominated biphenyls (PBBs) and

Polybrominated diphenylethers (PBDEs)

Br

BrBr

Br

O Br

Br

Br

Br

•Used as flame retardants•In 1970s technical mixtures of penta to decabromo congeners produced•Because of high potential of less brominated congeners to bioaccumulate today only decabromo diphenylethers•Similar health effects to PCBs, PCDD/Fs and PCNs

Typical sediment contaminantsHalogenated aromatic hydrocarbonsDDT (dichloro-diphenyl-trichloroethane) and metabolites

• Insecticide•very toxic to insects: opens Na ion channels in neurons

• low acute toxicity to humans and mammals

p,p’-DDT

o,p’ DDT (impurity in technical DDT)

p.p’-DDE (dichloro-diphenyl-dichloroethene)

p,p’-DDD (dichloro-diphenyl-dichloroethane)

major transformation products in the environment

Typical sediment contaminantsDDT (dichloro-diphenyl-trichloroethane) and metabolites

Application: Agriculture and disease control (e.g. Malaria, Typhus)

History: 1874 synthesized for the first time by Othmar Zeidler1939 discovery of insecticide activity by Paul Hermann Müller (Nobel

Prize 1948)1943/44 typhus epidemic in Neapel - application for control of lice as

insect vectors for typhus agentsduring second world war intensive use for control of biting midges and Malaria

1945 license for application in agriculture in USA, later also in Europe1950s “Maikäferkrieg” in Switzerland (big amounts

of DDT sprayed from airplanes) → damaging bees and other important insects

1947-1960s Control of the “Ulmensplintkäfer” in the U.S. → disappearance of birds

Typical sediment contaminantsDDT (dichloro-diphenyl-trichloroethane) and metabolites

1956 control of “Schwammspinner” in the State of New York on 12.000km2 → fish kills, milk couldn’t be sold any more

1983/84 application of 600 t of DDT to control “Borkenkäfer”

Intensive use of DDT till today against Anopheles to control Malaria in tropical countries

Typical sediment contaminants

Rachel Carson

1962 Publication of “Silent Spring” by Rachel Carson → Risks and Damages by DDT and other pesticides → Starting point of intense public discussion1972 prohibition of DDT use in the U.S. and BRD

Properties: DDT•is highly persistent•is highly lipophilic (log KOW 6.2)•accumulates in soils and sediments•bioaccumulation and biomagnification in the food chain•high concentrations in and severe effects on top predator birds.

Example: almost complete break down of peregrine falcon (Wanderfalken) populations in Great Britain in the 1960s due to reduced thickness of egg shells caused by DDT and other halogenated compounds such as PCBs.

Typical sediment contaminantsOther halogenated pesticides typically accumulated in sediments

γ-hexachlorocyclohexane, lindane

insecticide used since 1942 in agriculture and forestry but also against human skin parasitesforbidden in EU since 2007moderately lipophilic (log KOW 3.7)

toxaphene

complex mixture of C10H10Cl8 isomersmost applied insecticide worldwide 1 Mio t between 1946 and 1993since 2004 globally forbidden (Germany since 1971)persistent, bioaccumulating (log KOW 5.3) relatively volatile (atmospheric transport)mutagenic, carcinogenic, teratogenic

Typical sediment contaminantsOther halogenated pesticides typically accumulated in sediments

hexachlorobenzene

used against fungi in cerealspersistent, lipophilic, bioaccumulatingsince 1981 forbidden in Germany

Typical sediment contaminantsPlasticizers and detergents

Diethylhexylphthalate (DEHP)

Used as plasticizer in many plasticsUbiquitous in the environmentActivity as endocrine disruptorvery lipophilic (log KOW 8-9.6)

Bisphenol A

Used for production of polycarbonate plasticsModerately lipophilic log KOW 3.3Endocrine disruptor, mutagenicDisturbs development of mammals and birds

OH

OH

OH

OH

OH

OH

OH

Typical sediment contaminantsPlasticizers and detergents

OH

p-Nonylphenols

Anaerobic degradation products of nonylphenol polyethoxylates (NPnEO, surfactants) → annual production 240000 t worldwide

Technical mixture of many differently branched isomersToxic and endocrine disruptors

Typical sediment contaminantsAlkylphosphates

Tributylphosphate (TBP)

Solvent and plasticizer for cellulose esters, inks, resins, gums, adhesives….

P

OO

OO

Cl

Cl

Cl

Tris(2-chloroethyl)-phosphate (TCEP)

Similar use as TBPneurotoxicprobably carcinogenic

Typical sediment contaminantsAlkylphosphates

Typical sediment contaminantsPersonal care products

Galaxolide (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzopyrane, HHCB)musk fragrance in many cosmetic productspersistentlog KOW 5.9

CH3

CH3CH3

CH3

CH3 CH3

CH3

O

Tonalide (6-Acetyl-1,1,2,4,4,7-hexamethyltetralin AHTN)

musk fragrance in many cosmetic productspersistentlog KOW 5.7

Typical sediment contaminantsPersonal care products

Triclosan

Disinfectant in many toothpastes, deodorants…potent biocideModerately lipophilic log KOW 4.7

Methyl triclosan

Formed in waste water treatment plants by microorganisms from triclosanenhanced bioaccumulation potentiallog KOW 5.2Often found in higher concentrations in biota and sediments than triclosan

O

O

ClCl

ClCH3

Typical sediment contaminants

Perfluorinated surfactants

perfluorooctylsulfonate

Repel water and oil⇒impregnation of carpets, textiles and packaging material

perfluorooctanoic acid

emulgator in teflon production

fluorotelomeralcohols

impregnation of food packages against water and oil

extremely stable, highly persistent and bioaccumulating

Typical sediment contaminantsOrganotin compounds

Tributyltin, Triphenyltin

PVC stabilizersAntifouling agent for shipsBiocide in many consumer products

One of the most toxic compounds used by man

1985

worldwide 35000 t of organotin compounds (1985)since 2008 prohibition of TBT as antifouling agent for ships

SnH

Typical sediment contaminantsOrganotin compounds

highly potent endocrine disruptor (androgenic)→ development of male genitals in female snails already at few ng/L⇒ imposex, effects on reproduction⇒ today coastal snail populations globally affectedimposex and high toxicity also in fish

Dose-response-relationships of TBT in snails (µg/g dry weight) /in water and imposex in snails

Typical sediment contaminantsExample: Sediments from the River Elbe in 2002

Stachel et al. 2005

Typical sediment contaminantsExample: Sediments from the River Elbe in 2002

Sediments as long-term memory

For persistent organic contaminants and metals sediment cores reflect the history of contamination

Example:Sediments in California coastal area receiving municipal waste effluents since about 1950 Eganhouse and Gosett (1991) in Baker: Organic substances and

sediments in water. Vol. 2

Example: Reflection of DDT production in sediments

Fent (1998) Ökotoxikologie

Sediments as long-term memory

Example: Reflection of PCB sales in sediment concentrations

Fent (1998) Ökotoxikologie

Sediments as long-term memory

Dating of sediment layers

1) Measurement of tracers associated to certain events – Example 137Cs

-Artificially introduced to atmosphere-Sources:

-Atmospheric tests of nuclear weapons 1953 to 1963-Fallout of the reactor accident of Tschernobyl 1986

How do we know about the age of sediment layers?

Sediments as long-term memory

Example: Dating a sediment core in the ox-bow lakel „Haken“ (Elbe flood plain) using 137Cs

Sediments as long-term memory

Dating of sediment layers2) Using lead-210 to assign dates

-Ocurring in the uranium-238 decay series:

- All metals except 222Rn (noble gas)- Emission of 222Rn from uranium containing rocks to atmosphere- Decay in few days to 210Pb ⇒ Fallout and accumulation in top sediment layers

Sediments as long-term memory

- Decay with a half-life period of 22.3 years according to:

teCC 210)0( λ−•= λ210 = decay constant of 210Pb

Example: Dating of Sempach Lake sediments

Applicable for a time frame of 50 years with uniform sedimentation

Sediments as long-term memory

Sediments as long-term memory

Geochronologie von anthropogenen Schadstoffen in mitteleuropäischen Flusssedimenten

Lucas Streib, Jörg Staffel

Referat