Polycyclic Aromatic Hydrocarbons in the Great Lakes

47 Pages·2006·0.84 MB·English

HdbEnvChemVol.5,PartN(2006):307–353
DOI10.1007/698_5_044
© Springer-VerlagBerlinHeidelberg2005
Publishedonline:9December2005
PolycyclicAromaticHydrocarbonsintheGreatLakes
MattF.Simcik1 ((cid:1))·JohnH.Offenberg2
1DivisionofEnvironmentalHealthSciences,SchoolofPublicHealth,
UniversityofMinnesota,MMC807,420DelawareStreetSE,Minneapolis,MN55082,
USA
[email protected]
2DepartmentofEnvironmentalSciences,Rutgers,TheStateUniversityofNewJersey,
14CollegeFarmRoad,NewBrunswick,NJ08901,USA
[email protected]
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
2 Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
2.1 PyrogenicandPetrogenicSources . . . . . . . . . . . . . . . . . . . . . . . 311
2.2 NaturalNon-CombustionSources . . . . . . . . . . . . . . . . . . . . . . . 317
2.2.1 Retene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
2.2.2 Perylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
3 Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
3.1 Gas/ParticlePartitioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
3.2 Reactivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
3.3 Air-WaterExchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
3.3.1 PrecipitationScavenging . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
3.4 Deposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
3.5 Dissolved/ParticlePartitioning. . . . . . . . . . . . . . . . . . . . . . . . . 329
3.6 Bioaccumulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
4 Sinks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
4.1 Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
4.2 Precipitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
4.2.1 Rain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
4.2.2 Snow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
4.3 Sediments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
4.3.1 OpenLake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
4.3.2 Nearshore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
5 Toxicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
5.1 DirectToxicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
5.2 Photo-enhanced Toxicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
6 LessonsLearnedfortheFuture . . . . . . . . . . . . . . . . . . . . . . . . 346
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Abstract Polycyclic aromatichydrocarbons (PAHs) are produced during the incomplete
combustion of organic material. They can also be produced through natural, non-
combustion processes, and may be present in uncombusted petroleum. Uncombusted
308 M.F.Simcik·J.H.Offenberg
petroleumcanbeadirectsourcetothewatersoftheGreatLakes,butcombustionsources
dischargePAHsintothecoastalatmosphere. Atmospheric depositionof combustion re-
latedPAHsseemstobethedominatesourcetotheGreatLakes,exceptinnearshoreareas
wherepointsourcescanbesignificant.Onceairborne,PAHspartitionintheatmosphere
betweenthegasandparticlephasesandcanundergolong-rangetransport.Duringtrans-
port, PAHs can be degraded or modified by photochemical reactions. Both the original
PAHspeciesandtheirdegradationproductscanbewashedoutoftheatmospherebywet
anddrydeposition,air–waterexchangeandair–terrestrialexchange.Onceinanaquatic
system, PAHspartitionbetweenthedissolvedandparticlephases. In general,PAHsare
particlereactiveandsettleoutinsediments.PAHcontaminationofGreatLakessediments
arehigherinthenearshoreregionswhereports,harbors,andurban/industrialareasare
thedensest.Intheopenlakearea,sedimentconcentrationsareratheruniform,withLake
SuperiorhavingslightlylessPAHsinitssurficialsediments.ThatportionofthePAHsthat
doesnotpartitiontoparticlescanbioaccumulateinthelipidreservesoforganisms.PAHs
accumulatedinanorganismmaybemetabolizedtomoretoxicby-productsorexerttoxi-
cityinitsoriginalform.Whencombinedwithultravioletradiationthistoxicityisgreatly
enhanced. Incoastalareaswhereconcentrationscanbequitehigh,PAHscanbetoxicto
allformsofaquaticlifeduringatleastpartoftheirlifecycle.PAHsareexpectedtoremain
anecologicalthreattotheGreatLakeswellintothefuture.Thethreatmayevenincrease
withtheincreasingcombustionneededfortheincreasingpopulationcentersandgreater
transportationneeds.Ofparticularconcernistheshort-termincreaseinPAHconcentra-
tionsthatcanresultfromthedredgingofportsandharborswherehighlycontaminated
sedimentshavebeenburied.
Keywords GreatLakes·PAHs·Sediments·Air·Sources·Photo-enhancedtoxicity
Abbreviations
φ Fractionofcontaminantassociatedwithparticles
φ Fractionofcontaminantassociatedwithfilter-retainedparticles
p,f
φ Fractionsofcontaminantassociatedwithnonfilter-retainedparticles
p,n,f
φT Fractionsofcontaminantassociatedwithallparticles
A Operationallydefinedgasphaseconcentration
AOC Areaofconcern
aTSP SurfaceareaoftheTSP
Cair Totalconcentrationinair
C Dissolvedorganiccontaminantconcentrationinwater
d
Cg Gaseouscontaminantconcentrationintheatmosphere
Cp,air Concentrationboundtoairborneparticles
Cp,rain Particleassociatedconcentrationinrainwater
Crain Totalconcentrationinrain
DOC Dissolvedorganiccarbon
ELA Experimentallakesarea
EROD Ethoxyresorufin-O-deethylase
F Fluxoroperationallydefinedparticlephaseconcentration
F Absorptionflux
abs
FFPI Fossilfuelpollutionindex
fom FractionoforganicmatterontheTSP
F Volatilizationflux
vol
Fwet Wetdepositionflux
H Henry’slawconstant
PolycyclicAromaticHydrocarbonsintheGreatLakes 309
(cid:1)
H DimensionlessHenry’slawconstant
HOMO Highestoccupiedmolecularorbital
IADN IntegratedAtmosphericDepositionNetwork
K Watersolidparticlesdistributioncoefficient
d
Koc Organiccarbon–waterpartitioncoefficient
KOL Overallmasstransfercoefficient
Kow Octanol-waterpartitioncoefficient
LUMO Lowestunoccupiedmolecularorbital
MWOM Molecularweightoftheorganicmatterphase
NS Surfaceareaconcentrationofadsorptionsites
P Precipitationflux
p0 Sub-cooledliquidvaporpressure
L
PAHs Polycyclicaromatichydrocarbons
Q1 Enthalpyofdesorption
Qv Enthalpyofvolatilization
R Molargasconstant
SEMw Standarderroroftheweightedmean
SPM Concentrationofsuspendedparticulatematter
SQC Sedimentqualitycriteria
T Temperature
TSP Concentrationoftotalsuspendedparticulatematter
UCM Unresolvedcomplexmixture
V Depositionvelocity
d
VWM Volumeweightedmean
Wg Gasscavengingratio
Wp Particlescavengingratio
WQC Waterqualitycriteria
WT Totalscavengingratio
ζOM Activitycoefficientoftheabsorbateintheorganicmatter
∆Hexcess Freeenthalpyofdissolution
∆HF Enthalpyoffusion(melting)
∆HH EnthalpyoftheH
∆H Enthalpyofdissolution
sol
∆Hvap Enthalpyofvaporization
∆Hvap Enthalpyofvaporization
∆Svap Entropyofvaporization
1
Introduction
Polycyclicaromatichydrocarbons(PAHs)areorganiccompoundscontaining
two or more aromatic rings. They are the product of incomplete combus-
tionoforganicmatter,theproductofdiagenesis oforganiccompounds, and
are present in uncombusted petroleum. Because they have both natural and
anthropogenic sources,therehavealwaysbeen PAHspresent intheenviron-
ment.However,withtheIndustrialRevolutionanditsincreaseincombustion
forheat,energy,andmanufacturing,PAHconcentrationsintheenvironment
310 M.F.Simcik·J.H.Offenberg
haveincreaseddramatically.PAHsareofenvironmentalconcernbecausethey
arepersistent,bioaccumulativeandtoxic.
PAHs have been found all over the globe in all compartments of the en-
vironment. They are ubiquitous because the are persistent. Recalcitrance in
PAHs may stem, in part, from the delocalized electrons in the planar pi or-
bitalsofthearomaticstructure.Theirrelativelyhighoctanol-waterpartition
coefficients, K s, make them rather lipophilic. The lipophilicity of PAHs
OW
forcesthemfromthedissolvedphasetoparticlesandalso intolipidrichor-
ganisms, but they can be metabolized in higher organisms. However, these
metabolites are often more toxic than their parent PAHs. When combined
with other stressors, particularly ultraviolet radiation, PAHs can exert en-
hancedtoxicity.
TheUSEnvironmentalProtectionAgencyhasidentified 16priorityPAHs
due to their known or suspected carcinogenicity. The structures of these 16
PAHsarepresentedinFig.1,buttherearealmostlimitlesspossibilitiestothe
numberofPAHsthatcanbeproduced.Inadditiontothestructurespresented
in Fig.1, PAH can also have alkyl chains or heteroatoms within their rings.
Thesecompoundsaremostoftenproducebythecombustionoforganicma-
terial.Inthischapterwewilldiscussthesources,transport,sinksandtoxicity
ofPAHsandhoweachoftheseareasrelatestotheGreatLakes.
Fig.1 Structuresofthe16EPApriorityPAHs
PolycyclicAromaticHydrocarbonsintheGreatLakes 311
2
Sources
There aremany more PAHsthan the EPA’s 16 prioritycompounds shown in
Fig.1. These include other parent compounds as well as alkylated species.
The large number of possible PAHs provides power to elucidate sources of
PAHstotheGreat Lakes.Becausedifferentsourcesproducedifferentrelative
amounts of each PAH, the relative concentrations of PAHs in environmental
mediacanbeusedtoidentifysignificantsourcesbackouttheircontributions
toenvironmentallevels.Somecompoundsthatareparticularlyhelpfulinthe
elucidation of sources, or may have both natural and anthropogenic sources
areshowninFig.2.
2.1
PyrogenicandPetrogenicSources
CombustionsourcesproduceawidearrayofPAHsfromlowtohighmolecu-
larweightspecies.ThesecombustionderivedPAHsareoftencalledpyrogenic
PAHs, and are recognized by the large presence of higher molecular weight
species(i.e.,>3rings).PyrogenicPAHsareformedduringthecombustionof
large biomolecules present in fossil fuels and contemporary carbonsources.
These biomolecules are pyrolized into small fragments that cool, polymer-
ize,andaromatizeintheexhaustofthecombustionprocess.Thecombustion
process can form the vast majority of PAHs found in the environment, but
different combustion sources often produce a small subset of PAHs and in
somecasesthereareuniqueindividualcompoundsspecifictocertainsources.
Fig.2 Structuresofsomesource-relevantPAHs
312 M.F.Simcik·J.H.Offenberg
For example, vehicular emissions can be identified by high concentrations
of benzo[ghi]perylene and coronene [1–5], and a unique tracer of vehicle
emissionsmaybecyclopenta[cd]pyrene[6–11].Anotherexampleofaunique
tracer is retene. Retene is a tracer for wood combustion, and although it
can also be produced fromnon-combustionsources, this isusually minimal
(see2.1.1). Other sourcesare characterized by their relative contributions of
several PAHs. Further differentiation between gasoline and diesel emissions
can often be elucidated by the high contribution of benzo[b]fluoranthene,
benzo[k]fluorantheneandindeno[cd]pyrenebydieselvehicles[2].Coalcom-
bustion contributes relatively higher concentrations of alkylated PAHs than
othercombustionsources[12,13].Alargesourceofenergyforheating,cook-
ing, and electrical generation in the Great Lakes Region [14], natural gas
combustion is characterized by high relative amounts of benz[a]anthracene
and chrysene [15]. Pyrogenic PAHs are a direct source to the atmosphere.
Onceintheatmosphere,thesePAHscanbetransportedanddepositedtothe
surfaceoftheGreatLakes(seetransportsection).
PetrogenicPAHs,foundinuncombustedpetroleum,canbeasourcetothe
atmosphere throughvolatilization or directly to the Great Lakes throughin-
tentionalorunintentionalspillstothewater.Unlikecombustionsources,dif-
ferentsourcesofuncombustedpetroleumcannotbereconciledbytheirPAH
signatures.However,uncombustedpetroleumcanproducedifferentPAHsig-
natures than combustion sources. As a volatilization source of PAHs to the
atmosphere, uncombusted petroleumnaturallyproducesmoreofthelighter,
less volatile PAHs such as naphthalene, acenaphthene, acenaphthylene. Un-
combusted petroleum is also relatively high in alkylated PAHs [16,17].
Boehm and Farrington [18] suggest that uncombusted, petroleum-derived
PAHs can be determined by the relative abundance of parent and alky-
latednaphthalenes,dibenzothiophenesandphenanthrenes.Theauthorscon-
structedaformulaforestimatingthecontributionofuncombustedpetroleum
calledthefossilfuelpollutionindex(FFPI)expressedas:
(cid:1)
(cid:2)
FFPI= naphthalenes(C –C ) (1)
0 4
(cid:2)
+ dibenzothiophenes(C –C )
0 3
(cid:2)
1
+ phenanthrenes(C –C )
0 1
2 (cid:3)
(cid:2) (cid:2)
+ phenanthrenes(C –C ) / PAHs
2 4
Boehm and Farrington [18] successfully applied this technique to marine
sediments. However,lacking the analyticalcapabilities toresolveallofthese
alkylated species, other techniques must be employed. It has been deter-
mined that the most environmentally stable alkylated dibenzothiophenes
PolycyclicAromaticHydrocarbonsintheGreatLakes 313
frompetroleumarethosewithamethylinthe4position[19],suggestingthat
4methyldibenzothiophenecouldbeagoodtracerofuncombustedpetroleum.
Other techniques involvelookingat thealiphatic hydrocarbonsforanypref-
erence inoddchainlengthn-alkanesoverevenchainlengthn-alkanesoran
unresolvedcomplexmixture(UCM).Petroleumresidues shownopreference
of odd or even chain length n-alkanes whereas plant waxes show a predom-
inance of odd chain length n-alkanes [20]. An unresolved complex mixture
is a large response underneath the n-alkane chromatogram of a gas chro-
matographymass spectrometry runand isindicative ofeither uncombusted
petroleumormicrobialactivity[21].Theratioofunresolvedtoresolvedmass
inthechromatogramisthenusedasanothertoolforsourceattribution[22].
Highvaluesofunresolvedtoresolvedratios(>3)indicatepetroleumsources
wherelowervalues(<4)indicatemicrobialactivity[21].
Several ofthetechniques and tracers mentioned above have been used to
apportion sources of PAHs to the atmosphere and sediments of the Great
Lakes. Simcik et al. [14] used a multiple linear regression/factor analysis
model to apportion the PAHs in the Chicago, IL/southern Lake Michigan
atmosphere. The factoranalysis indicated individual orgroupsofindividual
PAHs that were co-correlated in the combined gas and particle phase con-
centrations.ThesePAHswerematchedupwithsourcesignatureinformation
to assign a specific source with each factor and then tracer compounds of
each factor were run ona multiple linear regression modelto apportion the
specificcontributionsofeachsourcetothetotalPAHconcentrationinair.Re-
sultsaresummarizedalongwiththe1994energyuseinIllinoisinFig.3.The
largest sourceofPAHs was concluded tobe coaluse followedby natural gas
and a relatively small percentage from vehicle emissions. It is important to
point outthat air sampling was conducted near thelargeindustrial complex
ofsouthernLakeMichiganwherethereisalotofcoalcombustionforpower
generationandthesteelindustry.
This large influence of coal combustion on PAHs to the atmosphere of
southern Lake Michigan is echoed in the PAH accumulation in the sedi-
mentsofthelake.Simciketal.[23]concludedthatcoalcombustionparticles
from the southern end of the lake were responsible for the majority of PAH
accumulation in the sediments of both the southern and northern basins.
Evidence for thisconclusion comes fromsimilarities among PAH signatures
in the sediments and air particles in Chicago, a lack of indication of un-
combusted petroleum in the sediments from calculations of FFPI [23] and
interpretationofaliphatichydrocarbons[24].Themostconvincingevidence,
however, is the correlation of total PAH accumulation in sediments of the
deep hole of the northern basin and coal use in Illinois over the same time
period (Fig.4). Taking a different approach to apportioning PAHs Chris-
tensenandZhang[25]concludedthatthedecreaseinPAHaccumulationafter
about 1950 was a result of a switch from coal combustion to oil and nat-
ural gas for home heating, and that the influence of coal combustion and
314 M.F.Simcik·J.H.Offenberg
Fig.3 SourceapportionmentofPAHsinChicago,IL/southernLakeMichiganatmosphere
(reprintedwithpermissionfrom[14])
Fig.4 Accumulation of PAHs in sediments of Lake Michigan and coal use in Illinois
(reprintedwithpermissionfrom[23])
PolycyclicAromaticHydrocarbonsintheGreatLakes 315
coke ovens decreases more slowly with increasing distance from the shore
than does the contribution from petroleum sources. While neither Simcik
et al. [23] nor Christensen and Zhang [25] saw a large influence of point
sourcestotheopenlakesediments,thenearshoreareasoftheGreatLakescan
beimpactedbylocalPAHsources.
There areseveral coastalareas withinthe Great Lakes that fallunder reg-
ulatory scrutiny by boththe Canadian and US governments because ofPAH
contamination.Thesesiteshavebeengiventhedesignationofareasofconcern
(AOCs).Ofthe46AOCsaroundtheGreatLakes,15specificallylistPAHcon-
taminationasareasonofconcern(ofteninadditiontoothercontaminants).
AlistoftheAOCscontaminatedwithPAHsissummarizedinTable1below.
Because PAHs are often co-located with other contaminants, this list is
by no means inclusive of the hot-spots of PAH contamination. Some other
AOCs around the lakes and areas not listed as AOCs may contain signifi-
cantPAHcontamination.Infact,thereareseveralSuperfundsitesaroundthe
Great Lakes that have been so listed because of PAH contamination. These
areasofPAHcontaminationarenothighlycontaminatedbecauseofregional
background sources of PAHs. In every case they have specific point sources
of contamination. Studies of nearshore sediments by the Christensen group
also show local sources of contamination in Lake Michigan. Rachadawong
et al. [26] concluded that Lake Michigan sediments in the Milwaukee basin,
nearMilwaukee,WI,arecontaminatedwithPAHsfromacombinationofcoal
Table1 GreatLakesareasofconcernidentifiedashavingaPAHproblem
AOC Lake State/Province
BlackR. Erie Ohio,USA
BuffaloR. Erie NewYork,USA
DetroitR. Erie Michigan,USA
Ontario,Canada
GrandCalumetR. Michigan Illinois,USA
HamiltonHarbor Ontario Ontario,Canada
MenomineeR. Michigan Wisconsin,USA
MilwaukeeEstuary Michigan Wisconsin,USA
NiagaraR. Ontario NewYork,USA
PresqueIsleBay Erie Pennsylvania,USA
SheboyganR. Michigan Wisconsin,USA
St.ClairR. St.Clair Michigan,USA
Ontario,Canada
St.LawrenceR.@Messena Ontario NewYork,USA
St.LouisR. Superior Minnesota,USA
St.Mary’sR. Huron Michigan,USA
Ontario,Canada
ThunderBay Superior Ontario,Canada
316 M.F.Simcik·J.H.Offenberg
combustionandpetroleumpointsources.Closertoshore,withintheMilwau-
kee Harbor, suggested sources are highway traffic and industrial discharges
including uncombusted petroleum and coal piles [27]. In Green Bay, which
is also amorenearshore environment than theopen lake, Su et al. [28] con-
cluded that coke, highway and wood burning were the dominant sources of
PAHstothesediments.FurtheruptheFoxRiver,whichflowsintoGreenBay
thesamesourceswereresponsibleforsedimentaryPAHcontamination[29].
Like coastal Lake Michigan, the Black River in Ohio is greatly influenced
by local sources. Gu et al. [30] concluded that historic contamination of the
sediments resulted from coke oven operation, but recent PAHs also receive
significant inputs from highway dust and wood burning. Interestingly, the
historic PAH contamination fromcoke ovens buried in the sediments of the
Black River were released upon dredging and acted as a major source of
PAH contamination to the river [30] and presumably to coastal Lake Erie.
Fluvial inputs and nearshore atmospheric deposition to coastal areas of the
Great Lakes has been shown by numerous studies for Lake Michigan [25–
29,31].SimilarconclusionshavebeenmadeforLakeErie.Smirnovetal.[32]
measured PAHs in the sediments of Lake Erie and found much higher con-
centrations in cores near Detroit, MI, Cleveland, OH and Buffalo, NY than
alongthesouthernshoreofthelake. Inturn,thesediments alongthesouth-
ern shore were much higher than the sediments in the northern portion
of the lake. Their conclusions were that the major source of PAHs to the
sedimentsofLakeEriearethethreemajorcitiesandfluvialinputs.Theatmo-
spheric contribution from Buffalo was confirmed by Cortes et al. [33] using
airconcentrationsandwinddirectionmeasuredontheshoreofLakeErie20
km southwest of Buffalo. The relative importance of Detroit and Cleveland
to atmospheric deposition of organic contaminants has been implicated by
Simcik [34] in which the author concludes that urban areas with a signifi-
cantlyhigherpopulationdensitythantheaveragedensityaroundthelakewill
contribute an elevated atmospheric source of persistent organic pollutants
including PAHs. Another suspected urban source of increased atmospheric
depositiontoLakeEriefromSimcik[34]isToledo,OH.Thisisincloseprox-
imity to Detroit and Cleveland, and therefore my be indistinguishable from
theothertwo.Simcik[34]alsoconcludedurbanareasofsuspectedincreased
atmosphericdepositionforeachoftheotherGreatLakes.
Lake Superior isexpected tohaveincreased atmospheric deposition from
Duluth, MN and Thunder Bay, Ontario [34]. This increase from Duluth has
been observed in both the atmosphere [35] and sediments [36] of west-
ern Lake Superior. Lake Michigan is suspected to have the greatest number
of urban areas affecting PAH deposition including Green Bay, Milwaukee,
Racine and Kenosha, WI and Chicago, IL and Gary, IN. Lake Huron is only
expected to have an urban influence from the Saginaw Bay area. Lake On-
tario is expected to have urban influences from Toronto and Hamilton, ON
andRochester,NY.Thenon-atmosphericinfluenceofHamiltonhasbeenob-