8 Toxicokinetics of Environmental Contaminants in Freshwater Bivalves Waverly A. Thorsen, W. Gregory Cope, and Damian Shea INTRODUCTION Bivalves have been used for decades as sentinel organisms to monitor pollution in the aquatic environment (Foster and Bates 1978;Farrington et al. 1983;Colombo et al. 1995;Peven, Uhler, and Querzoli1996; Blackmore and Wang 2003). Many different classes of chemicals have been studied in this way includinghydrophobic organic contaminants (HOCs),suchaspolycyclicaromatic hydrocarbons(PAHs), polychlorinated biphenyls(PCBs), andorganochlorine(OC)pesticides, as well as inorganiccontaminantssuchasthe heavymetals cadmium(Cd),lead (Pb) and mercury(Hg) and the radionuclides plutonium ( 239,240 Pu) and cesium ( 137 Cs). Theuse of bivalves for biomonitoring of environmental pollution addresses difficulties associated with determining aqueouscontaminant concentrations (Farrington et al. 1983). Many HOCs exhibit very low water solubilities (e.g., coronene:1.4! 10 K 4 mg/L,at25 8 C),which require largesamplesizes for adequate instrumental analysis. Moreover, trace metals require “ultraclean” techniques and are also frequently found in very low concentrations in the aqueousphase, sometimes at levels close to instrument detection limits(i.e., pg/L). Additionally, randomwater sampling may not capture real trends in pollutant concentrations over an integratedtimescale. In an attempt to overcome these obstacles, native bivalves are frequently collected worldwide, extracted, and analyzed for pollutant tissue burdens to provide preliminaryinformation at sites suspected of contamination or to monitor chemical and waste discharge effluents. However, to effectively understand and correlate the relationship betweenconcentrations of pollutantsinthe aquatic environment to concentrations in bivalve tissue and potential toxic effects, it is best to have an understandingofthe kinetics involved in the uptake, distribution, and elimination of pollutants by/from mussel tissues. Additionally, this information is required to understand and predict concen- trations in otherenvironmental compartments, such as predictingaqueousorsediment exposure concentrations from bivalve tissue burdens (Neffand Burns 1996). Traditionally,marine bivalves such as thebluemussel, Mytilusedulis ,havebeen used for environmental monitoring due to concern for pollution in coastal and estuarine areas (Farrington et al. 1983; Salanki and Balogh 1989; Beliaeffetal. 2002). However, more recently (1980s)fresh- water bivalves have been increasingly utilizedtoassess the quality of lakes, rivers, and streamsof concern, not only for the protectionofhumanhealth, but alsotobetter explain recent major declines of manyNorth American freshwater mussel populations (e.g., Keller and Zam 1991; Naimo1995; Jacobson et al. 1997). Generally, information gleaned from freshwater bivalveshas demonstrated similarities to marinebivalves; however,physiologies can vary greatly between species,age, body size, ingestion rate, reproductive state, stress,and location, among other factors(Landrumetal. 1994; 4284X—CHAPTER 8—17/10/2006—14:53—KARTHIA—XML MODEL C–pp. 169–213 169 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) Naimo1995; Morrison et al. 1996). Therefore, in an attempt to better evaluate pollutant fate and to effectively protect and remediatethe natural environment, it would be beneficial to understand the toxicokinetics of both marine and freshwater mussels. The intent of this chapter is to present back- ground information and to assess the toxicokinetic information available for freshwater bivalves (mussels and clams). Where data are limited, information on marine bivalveswill be presented and, in some cases, will be presentedintandemwithfreshwaterbivalve informationinacomparative context. This chapter is not meant to be an exhaustive review of the literature pertaining to these issues, but rather it is meant to aid researchers, managers, and others, in understanding the bioaccu- mulation of organic and inorganic contaminants in freshwater bivalves. U PTAKE AND E LIMINATION Bivalves are exposedtoand take up pollutants in tandem with their primary respiratory and feeding mechanisms; chemicals entermussels actively and passivelyasthey filter water through their gills for respiration and feeding (dietary exposure), or in the case of inorganiccontaminants such as metals,through facilitated diffusion,active transport,orendocytosis (Marigomezetal. 2002). Additionally, somebivalve species are exposedtopollutants through pedal feeding or gut ingestion of sediment (McMahon and Bogan 2001). Therefore, chemical uptake can occur in adirect fashion whenmusselsdraw large quantities of water (up to 11 L/mussel/day for Unionidae, Naimo1995) into their gills or, in an indirect fashion, when ingestion of sediment occurs and chemicalsdesorb (passively or through facilitated desorption) from the sediment particlesinto the bivalve gut and become assimilated. Once chemicalsenter theorganism,theypartition into or associate with tissues. For example, heavy metalswill accumulate primarily in muscles and organ (soft) tissues (Plette et al. 1999; Markich, Brown, and Jeffree2001; Marigomez et al. 2002)and organic pollu- tants will accumulateinthe lipid (Farrington et al. 1983; Di Toro et al. 1991). Generally, uptake is very rapidwhenthe bivalve is first exposed and then levels off, sometimes requiring extensive time periods foranequilibriumstate to be reached (Figure8.1a). Asimilar trend(Figure8.1b) is observedfor theeliminationprocess, which may be rapid at first and then leveloff,some compounds never being fully eliminated (i.e., somecompounds with half-lives of 20 years). Uptake and elimination rates for both HOCs and metalscan be determined through field and/or laboratory studies. One potential concern in these types of studies is the possibility that the bivalves stop siphoning. Although this is morelikely to influence studies of shorter duration, it shouldbe taken into consideration when analyzing the data.Atypical uptake/elimination experiment consists of “clean” bivalves (referenced or depuratedprior to commencement of the study) exposedtoa constant chemical concentration in water,and sampledatincreasing time intervals, to determinethe chemical concentrations in tissue over time. For example, bivalves can be collected from arela- tivelyuncontaminated field reference site, and deployed at acontaminated field site, or brought back to the laboratory for contaminant exposure. After sufficient exposure time,the organisms are removed and placed in clean water for measurement of the elimination (depuration) rate of the compounds. In the natural environment, elimination of certain chemicals might require extensive time periods. In locationswhere exposure levels areconstantorincreasing, bivalvesmay not eliminate the chemicals. In manyinstances, bivalves will accumulate contaminants to levels sig- nificantly higher than those in the water column. This can pose toxicity risks to the mussel and predatoryanimals or canresultinbiomagnificationand subsequent increases in contaminant concentrations progressively up the food web. B IOCONCENTRATION The accumulation of contaminants from the water column by bivalves is referred to as “bioconcen- tration.” Bioconcentration is defined as the partitioningofacontaminant from an aqueous phase into an organism andwill occurwhenthe contaminantuptakerate is greaterthanthatfor Freshwater BivalveEcotoxicology170 4284X—CHAPTER 8—17/10/2006—14:54—KARTHIA—XML MODEL C–pp. 169–213 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) elimination. Typically, thisleads to high concentrations of chemicals in bivalve tissues. For HOCs, partitioning generally occurs betweenthe dissolved phase of the water and the organism lipid. The most basic example of partitioning is defined as the octanol–water partition coefficient, or K ow : K ow Z ½ contaminant octanol = ½ contaminant water The K ow is ameasurement of achemical’s affinity for octanolversus water. In manycases, octanol is used as asurrogatefor the organism lipid. Achemical with alesser K ow value(less than 100) will partition less into the lipid than achemical with agreater K ow (greater than 1,000).This type of partitioning will occur between the aqueousphase and bivalve lipid until asteady-state condition has been reached (i.e., the concentration in the organism relative to the exposure system is unchan- ging with time). Once steady-state or equilibrium has been reached, it is generally referred to as “equilibriumpartitioning.” In asimplesystem, equilibriumpartitioning can be modeledby comparing theaffinities (i.e.,solubilitiesand fugacities) of achemical forbivalvelipid versus water (Figure 8.2). To determine the extent of bioconcentration of achemical in tissues, a“biocon- centration factor”orBCF can be calculated. TheBCF is defined as the pollutant concentration in the bivalveltissue ( C tissue )divided by the dissolved aqueouspollutant concentration ( C water )atsteady- state: BCF Z C tissue = C water 0 2 4 6 8 10 12 14 0100 (a) (b) 200 300 400 500 0100 200 300 400 500 Time (hours) Mussel concentration (ng/g) 0 2 4 6 8 10 12 14 Time (hours) Mussel Concentration (ng/g) FIGURE 8.1 Hypothetical uptake (a) and elimination (b) curve in afreshwater mussel. Note in this example, the rapid uptake that initially occurs, followed by aleveling offofthe concentration of the contaminant in mussel tissue. The leveling offisconsidered steady-state and, in this example, is reached following about 100 hours of exposure. The rate of elimination is also rapid and is essentially the reverse of the uptake curve. When placed in clean water, the mussels initially depurate the contaminant rapidly from their tissues and then reach aplateau, where no further elimination occurs on this time scale. Toxicokinetics of Environmental Contaminants in Freshwater Bivalves 171 4284X—CHAPTER 8—17/10/2006—14:54—KARTHIA—XML MODEL C–pp. 169–213 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) TheBCF can alsobedetermined by dividing the empirically derived contaminantuptake rate constant ( k 1 )bythe empirically derived elimination rate constant ( k 2 ): BCF Z k 1 = k 2 In general,the BCF is related to the hydrophobic character of the contaminant. In this way, BCF values typically correlate in alinear fashion to K ow values (Geyer et al. 1982; Mackay 1982; Hawker and Connell1986; Pruell et al. 1986; Schuurmann and Klein 1988; Thorsen2003)(Figure8.3). In many cases, asteady state bioconcentration regression equationcan be developed by linearly regressing alog BCF versusalog K ow plot. The resulting equation for the linetakes the form of log BCF Z m log K ow C b where m and b are the slope and y -interceptofthe line, respectively. This equation can modelthe bioconcentrationofhydrophobic organic pollutants by bivalves and can be used to predict aqueous exposure concentrations. C water- dissolved C mussel C water- particulate FIGURE 8.2 Diagram of theequilibriumpartitioning approach.The hydrophobic organiccontaminant partitions between the dissolved phase in the water column, the particulate phase in the water column, and the mussel lipid/tissues. According to Le Chaltelier’s principle, when asystem at equilibrium is disrupted (e.g., contaminantremoved from particulatephase by amussel),itwillshift to re-establish equilibrium (e.g.,systemresponds to change by contaminant fromdissolved phase binding to particulatephase). This model assumes all rates are relatively rapid. y =1.024 x − 1.8183 R 2 =0.8741 0 1 2 3 4 5 6 3456 log K ow log BCF 7 FIGURE 8.3 Example of alinear regression plot of log BCF versus log K ow ,based on empirical data (From Thorsen, W. A., Bioavailability of particulate-sorbed polycyclic aromatic hydrocarbons, PhD Thesis, North Carolina State Univ., Raleigh, NC, 2003). Linear regression has been performed and the resultant regression equation takes the form: log BCFZ m log K ow C b .This regression equation (through simple mathematical procedures) can be used to predict aqueous exposure concentrations based on tissue residues. Freshwater BivalveEcotoxicology172 4284X—CHAPTER 8—17/10/2006—14:54—KARTHIA—XML MODEL C–pp. 169–213 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) The “partitioning” of metals, however, generally refers to the adsorption of metalsonto active sites in/on target tissues, such as anionic sites on bivalve gills (Kramer et al. 1997;Marigomez et al. 2002), rather than absorption into abivalve lipid. Abioconcentration factor, though slightly less utilitarian than for HOCs due to very slow uptake rate constants, can similarly be computed by BCF metal Z C tissue = C water where C tissue is the moles of metal per gram of soft weight tissue and C water is the moles of metal dissolved per mL (or L) of water. This BCF value must also be calculated when the system has reached steady-state. More complexequations existfor predicting bioconcentration (and uptake, elimination rates) whenasystem is not at steady state and are discussedelsewhere (Russell and Gobas 1989; Butte 1991). Thebioconcentration of metals is affected by many factors, including water pH, hardness, alkalinity, conductivity, and dissolved organic and inorganic matter, which will be discussed in following sections. B IOACCUMULATION While bioconcentration refers only to the uptake of chemicals directly from the water, the term bioaccumulation does not differentiate betweenuptakemedia and includeschemical accumulation into organisms from both abiotic (i.e., water and sediment) and biotic (i.e., food) sources. For example, bivalves canbioaccumulate chemicals andmetals from thewatercolumnand the sediment phase in the natural environment.Typically, scientists may model this relationship by calculating either abioaccumulation factor (BAF) or abiota-sediment accumulation factor (BSAF). The BAF includesexposure due to water and food sources, whereasthe BSAF (onlyused for HOCs) models the partitioning/association of achemical betweenthe lipid phasesinthe organism and the sediment, where the sediment “lipid”phase is considered to be organic carbon. The BAF is represented by BAF Z C tissue = C food C C water C C other exposures whereasthe BSAF is mathematically defined as BSAF Z ð C tissue = lipid fractionÞ = ð C sediment = organic carbon fractionÞ where the chemical concentration in the bivalve ( C tissue )and sediment ( C sediment )are normalized to the mass fraction of organism lipid and sediment organic carbon, respectively. Similar to the BCF calculation, aBSAF valueiscalculated when the chemical has reached asteady-state within the studysystem. Theoretically, BSAF values will equal unity or one. However, BSAF values may be less than one if the bivalve metabolizes the chemical or the system has not reached steady-state (chemicals may not be fully available to the organism due to very slow desorption or very strong binding).BSAF values can alsobegreater than one because organic carbon is generally less“lipid-like” than the organism lipid due to hydrophilic components of natural organic matter (DiToroetal. 1991).The calculationofBSAFvalues canlend informationabout aparticular chemical’s bioavailability(see Bioavailabilityand Biotic LigandModels). Metalsdonot interact with organisms in the environment in the same way that HOCs do. As previously mentioned, while HOCsgenerally partition ( absorb) into the lipid phase of abivalve, metals adsorb to the gill and other anionic sites on tissue surfacesorare actively transported via membranepumps.For example, metals such as cadmiumcan enter abivalvebybinding to Toxicokinetics of Environmental Contaminants in Freshwater Bivalves 173 4284X—CHAPTER 8—17/10/2006—14:54—KARTHIA—XML MODEL C–pp. 169–213 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) membrane transport ligands.Bioaccumulation of metals, including filtration of water and ingestion of food particles, in bivalves can be similarly measured through the use of aBAF: BAF Z C tissue = C water; dissolved Bioaccumulation factors for metalsare more difficult to interpret than for organics because the interactions between atarget site (biological organism) and the metal are complicated by compe- tition for binding sites and many moreenvironmental variables than simply dissolved or particulate organic carbon. For all chemicals and metals, bioaccumulation is the balance betweenall means of chemical uptake and all means of elimination. M ETABOLISM AND B IOTRANSFORMATION For those contaminants that bivalvesare capable of metabolizing, BCF, BAF, and BSAFvalues will be decreased. In general, the lesser metabolic capacities in bivalvesmakes them adequate sentinels of aquatic environmental pollution (James 1989); however, bivalveshave been shown to metabolize certain classes of compounds better than others. For example, mussels possess only minimal abilities to biotransform PAHs, and therefore, are good sentinels of the accumulation of PAHs.Somemarinemussels ( M. edulis), however,havebeenshowntometabolizethe PCB, hexachlorobiphenyl (HCBP) (Bauer, Weigelt, and Ernst 1989), and therefore, will exhibit lower BCF values. Additionally, bivalves have been showntopossess detoxification systems including lowmolecular weight proteins like metallothionein (MT) andlysosomal granules that make metals complexand chelate, therebyalteringthe metaluptake/distribution/elimination kinetics (Naimo 1995;Tessier andBlais 1996; Vesk andByrne 1999; Byrne andVesk2000; Baudrimont et al. 2002). B IOAVAILABILITY AND B IOTIC L IGAND M ODELS Underlying all of the previous concepts is the notion of bioavailability. Bioavailabilitycan be defined as thepercentageofachemical fullyavailable foruptakebyanorganism.Different chemicals and inorganiccontaminants have uniquebioavailabilites, which will depend on many factorsincluding water conditions such as hardness, pH, temperature, and turbidity, as well as the physical–chemical characteristics of the compound such as water solubility, vapor pressure, and speciation (ionic state). For example, chemicals that exhibit very low water solubilities readily sorb to organic carbon phasesinthe water column, such as particulate or dissolved organic carbon (POC, DOC).The rate of desorptionand co-occurrence of themussel with theparticle(s) partially determines the chemical’s bioavailability. If the rate of desorption is rapid relative to the co-occur- renceofthe particle and the organism, the chemical may be fully bioavailable. However, if the rate of desorption is very slow,the chemical maynot be readilyavailable.HOCsmay frequently become associated with naturalorganic matter in theaqueous andsedimentphases, whereas metals may become complexed to various organic (DOC) and inorganiccompounds present in the water such as calcium and potassium carbonates (CaCO 3 ,KCO 3 ). Thebioavailability of achemical is important to understand both to ensure the protectionof aquatic organismsand to implementeffectiveand cost-efficient remediationtechniques. This is particularly important because underpredictions of toxicity can result in unacceptable risks to organisms, whereasoverpredictions of toxicity canrequire costly practicesfor clean-up. For instance, bivalve tissue burdens are traditionally compared directly to total aqueousorsediment- contaminant concentrations,without regard for the bioavailable fraction. This method can over- predict the actual exposure concentrations bivalves (and other aquatic organisms) receive and may result in costly, yet ineffective, remediation of asite. Moreover, sediment concentrations of total Freshwater BivalveEcotoxicology174 4284X—CHAPTER 8—17/10/2006—14:54—KARTHIA—XML MODEL C–pp. 169–213 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) metal do notalways correlate well with bivalve tissue burdens. Rather, it may be the speciation of the metal (e.g., Hg 2 C versus CH 3 Hg),orratio of metal concentration to the amountofacid-volatile sulfate in the sediment (DiToro et al. 1992), that best determines the metal concentration in and subsequent toxicity to the bivalve. One can see the problemsthat may arise when regulatory and remediation techniques are based on incorrect assessmentsofchemical bioavailability. HYDROPHOBIC ORGANIC CONTAMINANTS U PTAKE As previously stated, HOCs primarily partition into abivalve lipid, which is considered essentially an “infinite sink” whereby saturation of the pool does not occur. Theuptake of ahydrophobic organic chemical into bivalve tissues can be defined mathematically as d C tissue = d t Z k 1 C water K k 2 C tissue where d C tissue /dt is the change in bivalve contaminant concentration over change in time ( t ), k 1 is the uptake rate constant of the chemical, C water is the aqueouschemical concentration, k 2 is the elimin- ation rate (see Elimination), and C tissue is the concentration of chemical in the bivalve (see Landrum, Lee, and Lydy 1992 for areview of toxicokinetic models). If the concentration of the pollutant in the water column changes, this change will be mirrored in the bivalve over several days to weeks. This processisconsidered first-order on anatural log(ln)basis. By integration,the above equation becomes C tissue Z ð k 1 = k 2 Þ C water ð 1 K e K k 2 t Þ : Bivalves primarily take up HOCs directly from the water column (Thomann and Komlos 1999; Birdsall, Kukor,and Cheney 2001) through theirgills,although some studies have suggested additional chemical inputs from dietaryexposure (Brieger and Hunter 1993; Gossiaux, Landrum, and Fisher 1996; Bjork and Gilek 1997; Raikow and Hamilton 2001), and direct sediment ingestion via pedal feeding mechanisms (McMahon and Bogan 2001; Raikow and Hamilton 2001). There is debate in the literature over the relative contribution of each of these uptake routes; however, it should be noted that once the system has attained steady-state (dC /dt Z 0), the route of contaminant exposure is irrelevant(Di Toro et al. 1991). Becauseoftheir minimal metabolic capabilitiesfor metabolizing the majority of HOCs (Farrington et al. 1983;James 1989), bivalves accumulatethesecontaminants to high levels in their lipid tissues, which can often reach manyorders of magnitude greater than the corresponding concentrations in water or sediment phases. Despite the common use of freshwater bivalvesfor monitoring aquatic environments, relatively little information is knownregarding HOC uptake rate constants, comparedwith that for marinebivalves. Moreover, much of the freshwater and marinedata represent only afew species. For instance, the majority of the freshwater uptake studies focus on Dreissena polymorpha,whereasthe majority of marineuptake studies use M. edulis. There are various ranges in reported k 1 values for freshwater bivalves depending on species,and study variablessuchastemperature,exposureenvironment, mussel size, andlipid content (Table 8.1a,b;Table 8.2a,b for study summaries, Fisheretal. 1993; Bruner, Fisher, and Landrum 1994; Gossiaux, Landrum, and Fisher1996; Fisheretal. 1999). However, based on the available data, most k 1 values compare well,with only afew exceptions (Table 8.1a). Many studies demonstrate initial rapid uptake during initial exposure for both freshwater and marine species (Lee,Sauerheber, and Benson 1972; Obana et al. 1983; Bjork and Gilek1997; Birdsall, Kukor, and Cheney 2001). For example, Birdsall, Kukor, and Cheney (2001) reportedrapid uptake of the PAHs naphthalene (N0), anthracene (AN), and chrysene (C0) by Elliptio complanata gills. Their data demonstrated that the Toxicokinetics of Environmental Contaminants in Freshwater Bivalves 175 4284X—CHAPTER 8—17/10/2006—14:54—KARTHIA—XML MODEL C–pp. 169–213 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) TABLE 8.1a Published Uptake and Elimination Rate Constantsfor Various Freshwater and Marine BivalveSpecies as aFunction of Chemical Class and Water Solubility Species Chemical Class a Log K ow k 1 (mL/g day) k 2 (day L 1 )References Freshwater E. complanata PAH (34) 3.37(N0)–7.64(CO) Thorsen (2003) PAH (38) 3.37(N0)–7.64(CO) PAH (45) 3.37(N0)–7.64(CO) 0.0400(PE)– 0.2600(26DMN0) E. complanata PAH (14) 3.92(AC)–6.75(DA) 0.0370(BkF)–0.0217(F0) Gewurtz et al. (2002) D. polymorpha PCP 5.12 369.0–2,133.00.8600–1.5600Fisher et al. (1999) C. fluminea PCP 5.12 0.3900–0.4000Basack et al. (1997) C. leana Pesticides (3)3.22(OX)–4.22(TBC) 24.2(TBC)–338.0(CNF) 0.0450(CNF)–0.0600(TBC)Uno et al. (1997) D. polymorpha PAH (2) 5.18(PY)–6.04(BaP)672.0(BaP)–32,737.0(BaP) 0.0240–0.3840(BaP) Gossiaux, Landrum, and Fisher(1996) PCB (2)5.90(PCP)–6.90(HCBP) 2,280.0(PCP)– 26,448.0(HCBP) 0.0240(HCBP)– 0.1920(PCP) D. polymorpha TCBT (8)6.73(28)–7.54(25)683.3(52)–848.7(80) 0.0052(27)–0.0226(21)Van Haelst et al. (1996a) D. polymorpha PCB (36) 5.60(42)–7.36(180) 0.0420(183)–0.1720(64) Morrison et al. (1995) A. anatina PCP 5.12 Makelaand Oikari (1995) P. complanata PCP 5.12 D. polymorpha PAH (2) 5.18(PY)–6.04(BaP)7,680.0(PY)–31,200.0(BaP)0.1920(BaP)–0.5760(PY) Bruner, Fisher, and Landrum (1994) PCB (2)5.9(TCBP)–6.9(HCBP) 9,120.0–40,320.0(HCBP) 0.1200(HCBP)– 0.5040(TCBP) D. polymorpha PAH (2) 5.18(PY)–6.04(BaP)10,272.0(PY)– 20,112.0(BaP) 0.0090(PY, BaP) Fisher et al. (1993) PCB (2)5.90(TCBP)–6.90(HCBP) 4,008.0–25,752.0(HCBP) 0.0040(HCBP)– 0.0170(TCBP) OC (1)6.19(DDT)2,976.0–17,664.0(DDT) 0.0070–0.0080(DDT) D. polymorpha PCB (2)6.36(77)–7.42(169) 551.0(77)–1,480.0(169) 0.0340(169)–0.0350(77) Briegerand Hunter (1993) E. complanata HCB, OCS 5.45(HCB)–6.29(OCS) 650.0(HCB)–1,010.0(OCS) 0.4100(HCB)–0.1600(OCS) Russell andGobas (1989) Freshwater BivalveEcotoxicology176 4284X—CHAPTER 8—17/10/2006—14:54—KARTHIA—XML MODEL C–pp. 169–213 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) Marine M. edulis PCB (3)5.67(31)–6.92(153) 2,160.0–168,000.0(153)0.0288(153)–0.1368(31) Bjork and Gilek (1997) C. virginica PAH (7) 4.57(P0)–7.0(IP) 0.0200(FL)–0.0770(BaP) Sericano, Wade, and Brooks (1996) PCB (9)0.0053(149)–0.01540(110) M. mercenaria PAH (9) 3.37(N0)–6.04(BaP) ND over 45 days Tanacredi and Cardenas (1991) C. virginica PAH (14) 4.57(P0)–6.50(BghiF) 330.0(P0)–2,365.0(MPY) 0.0090(BF)–0.1180(FL)Benderetal. (1988) M. mercenaria PAH (14) 4.57(P0)–6.50(BghiF) 187.0(MP0)–2,842.0(BaA) 0.0870(BaP)–0.2130(FL) M. edulis PAH (6) 3.90–6.100.0231(FL)–0.0578(BkF)Pruell et al. (1986) PCB (4)5.00–6.600.0150(HCBP)– 0.0420(TCBP) Short-necked clam PAH (4) 4.42(D0)–5.89(D3) 0.1000(D3)–0.2400(D2)Ogata et al. (1984) Oyster PAH (4) 4.42(D0)–5.89(D3) Mussel PAH (4) 4.42(D0)–5.89(D3) Abbreviations:AC=acenaphthene; BaP=beazo[a]pyrene; BghiF=benzo[ghi]fluoranthene;BkF=benzo[k]fluoranthene; C0=chrysene; CNF=chlornitrofen; D0=dibenzothiophene; DA=diben- zanthracene; D2=dimethyldibenzothiophene;D3=trimethyldibenzothiophene; 2,6DMN0=2,6-dimethylnaphthalene; F0=fluorene; FL=fluoranthene; HCB=hexachlorobenzene; IP=indenopyrene; N0=naphthalene; OC=organochlorine; OCS=octachlorostyrene;OX=oxadiazon;PAH=polycyclic aromatic hydrocarbon; PCB=polychlorinated biphenyl (number in parenthesesreferstoIUPAC PCB congener); PCP=pentachlorophenol; PE=perylene; PY=pyrene; TBC=thiobencarb; TCBP=tetrachlorobiphenyl; TCBT=tetrachlorobenzyltoluene. a Number in parentheses referstototal number of chemicals studied within the chemical class. Toxicokinetics of Environmental Contaminants in Freshwater Bivalves 177 4284X—CHAPTER 8—17/10/2006—14:54—KARTHIA—XML MODEL C–pp. 169–213 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) TABLE 8.1b Published Solubility Values, Bioconcentration Factors, and Half-Livesfor Various Freshwater and Marine Bivalves as aFunction of Chemical Class Species Chemical Class log K ow log BCF T 1/2 (days) References Freshwater E. complanata PAH (34) 3.37(N0)–7.64(CO) 1.54(N0)–4.66(PE)Thorsen (2003) PAH (38) 3.37(N0)–7.64(CO) 1.90(N0)–5.20(CO) PAH (45) 3.37(N0)–7.64(CO) 1.60(AN)–5.51(C4) 2.60(26DMN0)–16.50(PE) E. complanata PAH (14) 3.92(AC)–6.75(DA) 3.20(F0)–18.70(BkF) Gewurtz et al. (2002) D. polymorpha PCP 5.12 2.60–3.10 0.44–0.81Fisher et al. (1999) Corbicula fluminea PCP 5.12 1.73–1.78Basack et al. (1997) C. leana Pesticides (3)3.22(OX)–4.22(TBC) 2.34(OX)–4.14(CNF)11.60(TBC)–15.40(CNF)Uno et al. (1997) D. polymorpha PAH (2) 5.18(PY)–6.04(BaP)4.34(PY)–5.43(BaP) 1.75(BaP)–28.80(BaP) Gossiaux, Landrum, and Fisher(1996) PCB (2)5.90(PCP)–6.90(HCBP) 4.00(PCP)–5.74(HCBP) 3.60(PCP)–28.80(HCBP) D. polymorpha TCBT (8)6.73(28)–7.54(25)4.43(80)–5.19(27)18.60(80)–71.80(22)Van Haelst et al. (1996a, 1996b) D. polymorpha PCB (36) 5.60(42)–7.36(180) 4.00(64)–16.50(183) Morrison et al. (1995) A. anatina PCP 5.12 1.90–2.10 Makelaand Oikari (1995) P. complanata PCP 5.12 1.80–1.90 D. polymorpha PAH (2) 5.18(PY)–6.04(BaP)4.11(PY)–4.92(BaP) 1.20(PY)–3.60(BaP) Bruner, Fisher, and Landrum (1994) PCB (2)5.90(TCBP)–6.90(HCBP) 4.32(TCBP)–5.38(HCBP)1.40(TCBP)–5.80(HCBP) D. polymorpha PAH (2) 5.18(PY)–6.04(BaP)4.65(PY)–4.88(BaP) 2.60(BaP)–3.00(PY) Fisher et al. (1993) PCB (2)5.90(TCBP)–6.90(HCBP) 4.62(HCBP)–5.43(HCBP) 1.70(TCBP)–7.20(HCBP) OC (1)6.19(DDT)4.72–5.03(DDT) 3.60–4.30(DDT) D. polymorpha PCB (2)6.36(77)–7.42(169) 4.02(77)–4.45(169) 19.80(77)–20.40(169) Briegerand Hunter (1993) E. complanata HCB, OCS 5.45(HCB)–6.29(OCS) 3.56(HCB)–4.16(OCS) 1.70(HCB)–4.30(OCS) Russell andGobas (1989) Marine M. edulis PCB (3)5.67(31)–6.92(153) 4.70(49)–6.80(153)BAFs 5.00(31)–24.20(153) Bjork and Gilek (1997) C. virginica PAH (7) 4.57(P0)–7.00(IP)9.00(BaP)–26.00(FL) Sericano, Wade, and Brooks (1996) Freshwater BivalveEcotoxicology178 4284X—CHAPTER 8—17/10/2006—14:54—KARTHIA—XML MODEL C–pp. 169–213 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) [...]... PAH 17-day uptake, 32-day elimination 2 8- day uptake, 2 8- day elimination 2-day uptake, 45-day elimination 2 8- day exposure 20-day exposure, 14-day elimination 2 8- to 50-day uptake, 50-day elimination References Riley et al (1 981 ) Obana et al (1 983 ) Ogata et al (1 984 ) Pittinger et al (1 985 ) Pruell et al (1 986 ) Broman and Ganning (1 986 ) Hawker and Connell (1 986 ) Tanabe, Tatsukawa, and Phillips (1 987 ) Bender... PAH, 34– 48 Marine Oysters M edulis No 2 Fuel oil Water only 2 1- to 100-day exposure, rapid elemination 6-hour uptake Steady-state reached in 16 h 2-day exposure, 16-day elimination 6-hour uptake, 15-day elimination 21-day uptake, no steady-state reached 96-hour uptake, 72-hour elimination 14-day uptake, 15-day elimination Used excised gills 5-day uptake, 32-day elimination 20-day exposure, 20-day elimination... 0.965 K1.40 0 .85 8 K0 .81 0.96 1.097 1.042 0 .84 4 K1.54 K1. 28 K1.23 0 .85 0 .85 0 .83 0.163 1.52 0.71 0.494 1.03 0.62 0.311 1.63 0.64 PAH (35) PAH (45) PAH (6) PAH (4, all D0) Water, laboratory PAH (4, all D0) Water, laboratory PAH (4, all D0) Water, laboratory References Pruell et al (1 986 ) Geyer et al (1 982 ) Thorsen (2003) Thorsen (2003) Hawker and Connell (1 986 ) Ogata et al (1 984 ) Ogata et al (1 984 ) Ogata... Kow PCBs Clams k2[oyster k2 Physioligically-based model of bioaccumulation, food ration affected k1, but not k2 Boehm and Quinn (1977) Hansen et al (19 78) Riley et al (1 981 ) Obana et al (1 983 ) Ogata et al (1 984 ) Pittinger et al (1 985 ) Pruell et al (1 986 ) Broman and Ganning (1 986 ) Hawker and Connell (1 986 ) Tanabe, Tatsukawa, and Phillips (1 987 ) Bender et al (1 988 ) Tanacredi and Cardenas (1991) Serciano... and Gilek (1997) Bender et al (1 988 ) Bender et al (1 988 ) Thorsen (2003) Thorsen (2003) Thorsen (2003) Ogata et al (1 984 ) Ogata et al (1 984 ) Ogata et al (1 984 ) Thorsen (2003) Thorsen (2003) Thorsen (2003) Ogata et al (1 984 ) Ogata et al (1 984 ) Ogata et al (1 984 ) Basack et al (1997) Fisher et al (1993) Gossiaux, Landrum, and Fisher (1996) Makela and Oikari (1995) Freshwater Bivalve Ecotoxicology Phenanthrene... Environmental Contaminants in Freshwater Bivalves 4 284 X CHAPTER 8 17/10/2006—14:54—KARTHIA—XML MODEL C – pp 169–213 M edulis 179 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) 180 Freshwater Bivalve Ecotoxicology TABLE 8. 2a Summary of Exposure and Test Duration for Toxicokinetic Studies in the Peer-Reviewed Reference with Various HOC Classes and Freshwater and Marine Bivalves Species Exposure... Haelst et al (1996a) Pruell et al (1 986 ) Toxicokinetics of Environmental Contaminants in Freshwater Bivalves 4 284 X CHAPTER 8 17/10/2006—14:55—KARTHIA—XML MODEL C – pp 169–213 Pentachlorophenol Units not specified in reference 189 © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) 190 Freshwater Bivalve Ecotoxicology TABLE 8. 4 Comparison of Steady-State Bioconcentration Regression... day) 188 4 284 X CHAPTER 8 17/10/2006—14:55—KARTHIA—XML MODEL C – pp 169–213 TABLE 8. 3 Comparison of Bioconcentration/Bioaccumulation Factors and Uptake and Elimination Rate Constants for Similar Solubility HOC Analytes in the Peer-Reviewed Reference 5.20 P complanata 1 .80 –1.90 Benzo[a]pyrene 6.04 D polymorpha 4.40–5.40 9,960–32,736 0.020–0. 380 Water Benzo[a]pyrene 6.04 D polymorpha 4.60–4.90 7,920– 18, 240... 4. 38 to 5. 28 log bioconcentration in field exposures at temperatures from 4 to 248C The BaP log BCF values had a similar range in the laboratory for temperatures from 4 to 208C (4.60 (48C) to 5.43 (158C), Table 8. 1b) The log BCF values for PY (log Kow 5. 18) in both the field and laboratory ranged from 4.34 to 4 .89 , over a similar temperature range However, the authors were not convinced that steady-state... increase from 4 to 248C (3,240 versus 2,640 mL/g day, respectively) (Gossiaux, Landrum, and Fisher 1996) These © 2007 by the Society of Environmental Toxicology and Chemistry (SETAC) 4 284 X CHAPTER 8 17/10/2006—14:54—KARTHIA—XML MODEL C – pp 169–213 182 Freshwater Bivalve Ecotoxicology TABLE 8. 2b Summary of Variables Measured and Primary Findings for Various Bivalves Published in the Peer-Reviewed References . uptake, 32-day elimination Tanabe, Tatsukawa, and Phillips (1 987 ) C. virginica, M. mercenaria Field and laboratory PAH, 14 2 8- day uptake, 2 8- day elimination Bender et al. (1 988 ) Clams PAH 2-day uptake,. 0.0090(BF)–0.1 180 (FL)Benderetal. (1 988 ) M. mercenaria PAH (14) 4.57(P0)–6.50(BghiF) 187 .0(MP0)–2 ,84 2.0(BaA) 0. 087 0(BaP)–0.2130(FL) M. edulis PAH (6) 3.90–6.100.0231(FL)–0.05 78( BkF)Pruell et al. (1 986 ) PCB. Stich (1976) Clams Chronic pollution 120-day elimination Boehm and Quinn (1977) M. edulis PAHs Hansen et al. (19 78) (continued) Freshwater BivalveEcotoxicology 180 4 284 X CHAPTER 8 17/10/2006—14:54—KARTHIA—XML