PMC:2854002 / 4692-11243 JSONTXT

{"project":"MyTest","denotations":[{"id":"19961220-15543751-28495496","span":{"begin":145,"end":146},"obj":"15543751"},{"id":"19961220-17705659-28495497","span":{"begin":147,"end":149},"obj":"17705659"},{"id":"19961220-17695928-28495498","span":{"begin":150,"end":152},"obj":"17695928"},{"id":"19961220-18517308-28495499","span":{"begin":2067,"end":2069},"obj":"18517308"},{"id":"19961220-17705659-28495500","span":{"begin":2349,"end":2351},"obj":"17705659"},{"id":"19961220-15922398-28495501","span":{"begin":2378,"end":2380},"obj":"15922398"},{"id":"19961220-15543751-28495502","span":{"begin":2407,"end":2408},"obj":"15543751"},{"id":"19961220-18517308-28495499","span":{"begin":2067,"end":2069},"obj":"18517308"},{"id":"19961220-19544893-28495503","span":{"begin":2573,"end":2575},"obj":"19544893"},{"id":"19961220-19200572-28495504","span":{"begin":3815,"end":3818},"obj":"19200572"},{"id":"19961220-17948791-28495505","span":{"begin":5093,"end":5095},"obj":"17948791"},{"id":"19961220-15926558-28495506","span":{"begin":5548,"end":5549},"obj":"15926558"},{"id":"19961220-15926558-28495507","span":{"begin":6397,"end":6398},"obj":"15926558"}],"namespaces":[{"prefix":"_base","uri":"https://www.uniprot.org/uniprot/testbase"},{"prefix":"UniProtKB","uri":"https://www.uniprot.org/uniprot/"},{"prefix":"uniprot","uri":"https://www.uniprot.org/uniprotkb/"}],"text":"Methods\n\nSummary of Previous Experimental Studies\nThe sources of the sediment samples used in this study are described in previous publications (2,12−17) and the references cited therein. Sediment characteristics are summarized in Table 1. Triplicate sediment samples from Lake Hartwell and Hunters Point were characterized for PCBs following USEPA methods 3550B (hexane:acetone sonication), 3630B (activated granular copper to remove elemental sulfur), 3630C (silica gel column cleanup), and 8082 (PCB congener analysis). Duplicate sediment samples from Grasse River, Milwaukee River, and Niagara River were characterized following USEPA methods 3660B (sulfur cleanup), 3665A (sulfuric acid clean up), 3630C, and 8082. Triplicate sediment samples from Crab Orchard Lake were characterized using a sulfuric acid and copper cleanup followed by PCB congener analysis.\nTable 1 Sediment Physicochemical Properties for Lake Hartwell (LH), Hunters Point (HP), Grasse River (GR), Milwaukee River Location 1 (MR 1), Milwaukee River Location 2 (MR 2), Niagara River (NR)a, and Crab Orchard Lakeb Sediments Contaminated with PCBs\nphysicochemical property LH HP GR MR 1 MR 2\nTOC % 2.8 ± 0.5c 1.7d 5.17 ± 0.31e 3.22 ± 0.07e 3.70 ± 0.00e\nblack carbon % no data 0.29f 0.365 ± 0.035e 0.640 ± 0.065e 0.616 ± 0.013e\npetrographic information or microscopy observation a very small amount of fine coal like fragments presence of charcoal, coal and coke particles mostly vegetative debris presence of some coal-derived particles presence of some coal-derived particles\nsediment mass less than 63 μm % 96 19 70 74 76\nsediment mass in light sediment fraction % 1.2 4 12.4 7.1 11.6\nPCB concentration (μg/kg) 1250 9900 6820 45160 87400\nPCB mass in light sediment fraction % 18 68 64.5 40.3 43.5\nmass fraction of PCBs associated with Dapp,fast/R2 75 43 76 59 62\nmass fraction of PCBs desorbed in 1 month 78 35 91 80 85\na TOC = 0.83 ± 0.03%; black carbon = 0.258 ± 0.056%; arochlor 1254 PCB concentration = 330 (μg/kg). Data taken from ref (14).\nb Crab Orchard Lake sediment: TOC = 0.59%; the sediment comprised 16% clay, 70% silt, 14% sand; arochlor 1254 PCB concentration = 29153 (μg/kg); PCB congener mass fractions desorbed within 14 days ranged from 40 to 80%; black carbon % was not determined. Data taken from ref (12).\nc Data taken from ref (13).\nd Data taken from ref (2).\ne Data taken from ref (14).\nf Black carbon was taken as 29% of TOC which was estimated based on the average BC/TOC ratio for 6 samples described by Cho et al. (18) taken from an adjacent location in the same mudflat where the original HP sediment was sampled. Free aqueous phase PCB concentrations in Lake Hartwell, Hunters Point, Grasse River, and Milwaukee River sediments were determined using an alum (Al2(SO4)3·18H2O) flocculation centrifugation method. Differences between these experimental conditions are highlighted in the Supporting Information (SI). Free aqueous concentrations were determined in Niagara River sediment using a polyoxymethylene solid phase extraction owing to very low concentrations, and for Crab Orchard Lake sediment free aqueous concentrations were determined using a matrix SPME method (additional details are provided in the SI). Free aqueous PCB concentrations were reported based on duplicate or triplicate analyses. Pollutant desorption from all sediments was measured following a multiple step Tenax bead method. Individual experimental batch conditions and sampling times are provided in the SI. Total organic carbon (TOC) was measured in all cases by combustion in an elemental carbon analyzer following treatment with acid to remove carbonates. Black carbon (BC) was analyzed using a wet chemical oxidation method after pretreatment to remove non-BC materials (200).\nBiouptake experiments were carried out on the marine species Neanthes arenaceodentata and Leptocheirus plumulosus and the freshwater oligochaete Lumbriculus variegatus using 28-day sediment toxicity protocols as outlined in the SI. Tissues and digestive fluids were sonicated according to USEPA method 3550B and the lipid content of organisms was measured by spectrophotometric analysis. PCB concentrations in biolipids were reported based on duplicate or triplicate analysis.\n\nTheoretical Relationships\nAccording to Schwarzenbach et al. (19), the distribution coefficient between particulate organic matter and water can be estimated with a linear free energy relationship based on the organochlorine compound’s octanol−water partitioning coefficient KOW (-). The free aqueous concentration Caq (g/cm3) can then be related to the solid phase concentration CS (g/g) based on the fraction of organic carbon fOC (-) in the sediment and the KOW, according to eq 1, assuming the fraction of organic carbon in the sediment is analogous to the organic solvent octanol.\nBiolipid concentrations Clipid (g/g) can then be related to free aqueous concentrations according to eq 2 By combining eqs 1 and 2, Clipid can be related to CS according to eq 3\nMore recently, Landrum et al. (20) related the concentration of organochlorine compounds in the lipid of oligochaetes to the amount of chemical desorbed from sediment within 6 h as measured via a kinetic test in the form of a Tenax bead extraction. A relationship was obtained between the lipid-normalized concentration in the oligochaetes and the organic carbon normalized concentration in the sediment, f6h (g/g organic carbon), extracted with Tenax as shown in eq 4\nMoermond et al. (6) account for two pools of organic carbon in sediment; amorphous organic carbon (AOC) and black carbon (BC). The fraction of AOC equals the difference between the fraction of TOC and the fraction of BC (fAOC = fOC − fBC). The amorphous organic carbon−water partitioning coefficient KAOC (cm3/g) and the lipid−water partitioning coefficient KLIP (cm3/g) were both approximated by KOW, and a relationship between CS and Caq shown in eq 5 was obtained. The black carbon−water Freundlich coefficient (KFr,BC (g/g BC)(g/cm3)−n) accounts for PCB sorption to BC described by the Freundlich isotherm and was obtained using a KOW based estimate according to eq 6. The relationship in eq 6 was obtained for a Freundlich exponent n of 0.7. To maintain consistency with the other equations, the units of KFr,BC were adapted from those used by Moermond et al. (6).\nThe Caq values derived from eqs 5 and 6 were related to biolipid concentrations using eq 7, where KLIP is the PCB lipid−water partitioning coefficient"}

{"project":"2_test","denotations":[{"id":"19961220-15543751-28495496","span":{"begin":145,"end":146},"obj":"15543751"},{"id":"19961220-17705659-28495497","span":{"begin":147,"end":149},"obj":"17705659"},{"id":"19961220-17695928-28495498","span":{"begin":150,"end":152},"obj":"17695928"},{"id":"19961220-18517308-28495499","span":{"begin":2067,"end":2069},"obj":"18517308"},{"id":"19961220-17705659-28495500","span":{"begin":2349,"end":2351},"obj":"17705659"},{"id":"19961220-15922398-28495501","span":{"begin":2378,"end":2380},"obj":"15922398"},{"id":"19961220-15543751-28495502","span":{"begin":2407,"end":2408},"obj":"15543751"},{"id":"19961220-18517308-28495499","span":{"begin":2067,"end":2069},"obj":"18517308"},{"id":"19961220-19544893-28495503","span":{"begin":2573,"end":2575},"obj":"19544893"},{"id":"19961220-19200572-28495504","span":{"begin":3815,"end":3818},"obj":"19200572"},{"id":"19961220-17948791-28495505","span":{"begin":5093,"end":5095},"obj":"17948791"},{"id":"19961220-15926558-28495506","span":{"begin":5548,"end":5549},"obj":"15926558"},{"id":"19961220-15926558-28495507","span":{"begin":6397,"end":6398},"obj":"15926558"}],"text":"Methods\n\nSummary of Previous Experimental Studies\nThe sources of the sediment samples used in this study are described in previous publications (2,12−17) and the references cited therein. Sediment characteristics are summarized in Table 1. Triplicate sediment samples from Lake Hartwell and Hunters Point were characterized for PCBs following USEPA methods 3550B (hexane:acetone sonication), 3630B (activated granular copper to remove elemental sulfur), 3630C (silica gel column cleanup), and 8082 (PCB congener analysis). Duplicate sediment samples from Grasse River, Milwaukee River, and Niagara River were characterized following USEPA methods 3660B (sulfur cleanup), 3665A (sulfuric acid clean up), 3630C, and 8082. Triplicate sediment samples from Crab Orchard Lake were characterized using a sulfuric acid and copper cleanup followed by PCB congener analysis.\nTable 1 Sediment Physicochemical Properties for Lake Hartwell (LH), Hunters Point (HP), Grasse River (GR), Milwaukee River Location 1 (MR 1), Milwaukee River Location 2 (MR 2), Niagara River (NR)a, and Crab Orchard Lakeb Sediments Contaminated with PCBs\nphysicochemical property LH HP GR MR 1 MR 2\nTOC % 2.8 ± 0.5c 1.7d 5.17 ± 0.31e 3.22 ± 0.07e 3.70 ± 0.00e\nblack carbon % no data 0.29f 0.365 ± 0.035e 0.640 ± 0.065e 0.616 ± 0.013e\npetrographic information or microscopy observation a very small amount of fine coal like fragments presence of charcoal, coal and coke particles mostly vegetative debris presence of some coal-derived particles presence of some coal-derived particles\nsediment mass less than 63 μm % 96 19 70 74 76\nsediment mass in light sediment fraction % 1.2 4 12.4 7.1 11.6\nPCB concentration (μg/kg) 1250 9900 6820 45160 87400\nPCB mass in light sediment fraction % 18 68 64.5 40.3 43.5\nmass fraction of PCBs associated with Dapp,fast/R2 75 43 76 59 62\nmass fraction of PCBs desorbed in 1 month 78 35 91 80 85\na TOC = 0.83 ± 0.03%; black carbon = 0.258 ± 0.056%; arochlor 1254 PCB concentration = 330 (μg/kg). Data taken from ref (14).\nb Crab Orchard Lake sediment: TOC = 0.59%; the sediment comprised 16% clay, 70% silt, 14% sand; arochlor 1254 PCB concentration = 29153 (μg/kg); PCB congener mass fractions desorbed within 14 days ranged from 40 to 80%; black carbon % was not determined. Data taken from ref (12).\nc Data taken from ref (13).\nd Data taken from ref (2).\ne Data taken from ref (14).\nf Black carbon was taken as 29% of TOC which was estimated based on the average BC/TOC ratio for 6 samples described by Cho et al. (18) taken from an adjacent location in the same mudflat where the original HP sediment was sampled. Free aqueous phase PCB concentrations in Lake Hartwell, Hunters Point, Grasse River, and Milwaukee River sediments were determined using an alum (Al2(SO4)3·18H2O) flocculation centrifugation method. Differences between these experimental conditions are highlighted in the Supporting Information (SI). Free aqueous concentrations were determined in Niagara River sediment using a polyoxymethylene solid phase extraction owing to very low concentrations, and for Crab Orchard Lake sediment free aqueous concentrations were determined using a matrix SPME method (additional details are provided in the SI). Free aqueous PCB concentrations were reported based on duplicate or triplicate analyses. Pollutant desorption from all sediments was measured following a multiple step Tenax bead method. Individual experimental batch conditions and sampling times are provided in the SI. Total organic carbon (TOC) was measured in all cases by combustion in an elemental carbon analyzer following treatment with acid to remove carbonates. Black carbon (BC) was analyzed using a wet chemical oxidation method after pretreatment to remove non-BC materials (200).\nBiouptake experiments were carried out on the marine species Neanthes arenaceodentata and Leptocheirus plumulosus and the freshwater oligochaete Lumbriculus variegatus using 28-day sediment toxicity protocols as outlined in the SI. Tissues and digestive fluids were sonicated according to USEPA method 3550B and the lipid content of organisms was measured by spectrophotometric analysis. PCB concentrations in biolipids were reported based on duplicate or triplicate analysis.\n\nTheoretical Relationships\nAccording to Schwarzenbach et al. (19), the distribution coefficient between particulate organic matter and water can be estimated with a linear free energy relationship based on the organochlorine compound’s octanol−water partitioning coefficient KOW (-). The free aqueous concentration Caq (g/cm3) can then be related to the solid phase concentration CS (g/g) based on the fraction of organic carbon fOC (-) in the sediment and the KOW, according to eq 1, assuming the fraction of organic carbon in the sediment is analogous to the organic solvent octanol.\nBiolipid concentrations Clipid (g/g) can then be related to free aqueous concentrations according to eq 2 By combining eqs 1 and 2, Clipid can be related to CS according to eq 3\nMore recently, Landrum et al. (20) related the concentration of organochlorine compounds in the lipid of oligochaetes to the amount of chemical desorbed from sediment within 6 h as measured via a kinetic test in the form of a Tenax bead extraction. A relationship was obtained between the lipid-normalized concentration in the oligochaetes and the organic carbon normalized concentration in the sediment, f6h (g/g organic carbon), extracted with Tenax as shown in eq 4\nMoermond et al. (6) account for two pools of organic carbon in sediment; amorphous organic carbon (AOC) and black carbon (BC). The fraction of AOC equals the difference between the fraction of TOC and the fraction of BC (fAOC = fOC − fBC). The amorphous organic carbon−water partitioning coefficient KAOC (cm3/g) and the lipid−water partitioning coefficient KLIP (cm3/g) were both approximated by KOW, and a relationship between CS and Caq shown in eq 5 was obtained. The black carbon−water Freundlich coefficient (KFr,BC (g/g BC)(g/cm3)−n) accounts for PCB sorption to BC described by the Freundlich isotherm and was obtained using a KOW based estimate according to eq 6. The relationship in eq 6 was obtained for a Freundlich exponent n of 0.7. To maintain consistency with the other equations, the units of KFr,BC were adapted from those used by Moermond et al. (6).\nThe Caq values derived from eqs 5 and 6 were related to biolipid concentrations using eq 7, where KLIP is the PCB lipid−water partitioning coefficient"}