Dioxin-Like Toxicity in the Saginaw River Watershed: Polychlorinated Dibenzo-<Emphasis Type="Italic">p</Emphasis>-Dioxins,Dibenzofurans, and Biphenyls in Sediments and Floodplain Soils from the Saginaw and Shiawassee Rivers and Saginaw Bay,Michigan, USA

Sediment and floodplain soils in the Saginaw River Watershed, Michigan, USA, have been demonstrated to be contaminated with a variety of organic compounds, including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). Existing data indicate that, at some locations, the contamination exceeds human health risk-based regulatory levels and ecological risk-based screening levels. In this study, concentrations of PCBs including non-ortho coplanar congeners, PCDDs, and PCDFs were measured in more than 120 sediment and floodplain soil samples collected from the Shiawassee River (a tributary of the Saginaw River), the Saginaw River, and Saginaw Bay, to determine the sources and magnitude of contamination, and to elucidate the contributions from individual contaminant groups to the overall 2,3,7,8-tetrachlorodibezo-p-dioxin equivalents (TEQs). Sediment and soil extracts were also analyzed for total dioxin-like activity by means of the H4IIE-luc cell bioassay. Elevated concentrations of PCBs (>1000 ng/g, dry weight) were found in surface sediment and floodplain soil samples collected from the Shiawassee River near Chase Lake, from Middleground Island in the Saginaw River, and from subsurface sediments in Saginaw Bay. Concentrations of PCDDs and PCDFs in sediment and floodplain soils from the Saginaw River and Saginaw Bay were 2 to 3 orders of magnitude higher than concentrations in the samples from the Shiawassee River. The highest PCDD/F concentration (55,200 pg/g, dry weight in a subsurface layer) was found in sediment collected at the mouth of the Saginaw River. Concentrations of PCDFs were greater than the concentrations of PCDDs in sediment from the Saginaw River. 2,3,7,8-TCDF, 1,2,3,7,8-PeCDF, and 2,3,4,7,8-PeCDF were the major PCDF congeners found in sediments from the Saginaw River. The elevated concentrations of PCDFs, and the predominance of the less highly chlorinated PCDF congeners, in sediments from the Saginaw River were similar to previously determined characteristics of the PCDF contamination of the Tittabawassee River, another tributary of the Saginaw River. These results suggest the existence of a major source of PCDFs within the watershed. A few localized areas of high PCDD/F and PCB concentrations, with unique congener compositions, in the Saginaw River indicated the presence of other minor sources, such as wastewater treatment plants. PCDFs were the major contributors to TEQs in sediment and soils from the Saginaw River and Saginaw Bay. Approximately 30% of the samples analyzed in this study had values exceeding the screening level of 50 pg TEQ/g, dry wt, suggested for soils by the Agency for Toxic Substances and Disease Registry.     

Passive sampling provides evidence for Newark Bay as a source of polychlorinated dibenzo-p-dioxins and furans to the New York/New Jersey, USA, atmosphere

Freely dissolved and gas phase polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were measured in the water column and atmosphere at five locations within Newark Bay (New Jersey, USA) from May 2008 to August 2009 with polyethylene (PE) passive samplers. Mono- to octa-CDDs and mono- to hepta-CDFs were detected in bottom and surface waters at ≤ 20 pg/L with no clear gradient between sampling locations, suggesting freely dissolved PCDD/Fs are well mixed in Newark Bay. The most concentrated, freely dissolved gas phase congener was 2,7/2,8-dichlorodibenzo-p-dioxin (2,7/2,8-DiCDD), likely originating from photochemical conversion of triclosan in Newark Bay. Air-surface water gradients strongly favored net volatilization of PCDD/PCDFs from Newark Bay. Water-to-air fluxes of 2,7/2,8-DiCDD and 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), the most concentrated and the most toxic PCDD/PCDFs, respectively, were approximately 60 ng/m(2) per month and 14 to 51 pg/m(2) per month. Significant decreases in freely dissolved 2,3,7,8-TCDD concentrations with increasing freshwater near the Passaic River and conservative behavior during the summer of 2009 suggested Passaic sediments as a likely source of 2,3,7,8-TCDD to Newark Bay. Mass balance calculations implied that almost 50% of freely dissolved 2,3,7,8-TCDD delivered to Newark Bay from the Hackensack and Passaic Rivers was lost to volatilization in the summer of 2009.     

Polychlorinated naphthalenes, biphenyls, dibenzo-p-dioxins, and dibenzofurans as well as polycyclic aromatic hydrocarbons and alkylphenols in sediment from the Detroit and Rouge Rivers, Michigan, USA

Sediment from the upper Detroit and lower Rouge Rivers in southeastern Michigan, USA, were analyzed to examine the distribution of polychlorinated naphthalenes (PCNs), biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) as well as polycyclic aromatic hydrocarbons (PAHs) and alkylphenolic compounds such as butylphenol, octylphenol, and nonylphenol (NP). Sediments from a non-point source location in Lake Michigan were also analyzed for target compounds. Concentrations of target compounds in the upper Detroit and lower Rouge Rivers varied considerably among locations, and notable spatial variation existed. Concentrations of PCNs and PCDDs/PCDFs in sediments from the upper Detroit and lower Rouge Rivers ranged from 0.08 to 187 ng/g and 69 to 1420 pg/g dry weight, respectively. Total PCBs, PAHs, and NP concentrations ranged from 8 to 25,000, 17 to 44,000, and < 10 to 60,000 ng/g dry weight, respectively. Concentrations of all target compounds except PCNs were significantly correlated with total organic carbon content of sediments. Similarly, concentrations of PCBs, PCDDs, and PCDFs were significantly correlated with each other. The distribution of organic contaminants in the upper reaches of the Detroit River and lower Rouge River suggested the presence of localized, but multiple, sources of contamination for each compound class. Conners Creek combined sewer overflow has been identified as one of the potential sources for the upper Detroit River, where the highest concentrations PCBs and PCDDs/PCDFs were found. Polycyclic aromatic hydrocarbon and NP concentrations were consistently high in sediment from the lower Rouge River. Analysis of data from selected locations suggested that PCNs contributed a greater proportion of the dioxin-like activity than PCBs and PCDDs/PCDFs contributed.     

Polychlorinated Dibenzo-p-Dioxins (PCDDs), Dibenzofurans (PCDFs), Biphenyls (PCBs), and Organochlorine Pesticides in Yellow-Blotched Map Turtle from the Pascagoula River Basin, Mississippi, USA

Concentrations of polychlorinated-dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs), -biphenyls (PCBs), and organochlorine pesticides were measured in tissues of map turtles collected from two locations in the Pascagoula River drainage of Mississippi, USA. PCBs were most predominant among the organochlorines with a concentration of up to 99 ng/g, wet weight (580 ng/g, lipid weight) in livers. The greatest concentration of PCDDs/DFs of 1.1 pg/g, wet weight (15.76 pg/g, lipid weight) was found in the liver of a male turtle. The measured concentrations of organochlorines were less than those reported for turtles from the Great Lakes Basin and upper St. Lawrence River. PCBs contributed 90–99% of the total estimated 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs). Particularly, PCB congeners 105, 118, and 156 accounted for 68–80% of the estimated toxic potency of PCBs in turtles. Received: 4 May 1999/Accepted: 20 September 1999     

Polychlorinated Dibenzo-<Emphasis Type="Italic">p</Emphasis>-Dioxins,Dibenzofurans, and Dioxin-Like Polychlorinated Biphenyls in Livers of Birds from Japan

Concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and non- and mono-ortho-chlorine-substituted polychlorinated biphenyls (dioxin-like PCBs) were measured in livers of 17 species of birds collected from Japan. Birds were grouped according to their feeding habits as granivores, piscivores, omnivores, and predators for discussions. Livers of granivores contained relatively low concentrations of PCDD/DFs (80–660 pg/g) followed in increasing order by omnivores (2,300–8,000 pg/g), piscivores (61–12,000 pg/g) and predators (480–490,000 pg/g on a fat weight basis). Especially, one species of predatory bird (mountain hawk eagle) contained elevated concentrations of PCDDs, PCDFs, and dioxin-like PCBs, and the measured concentration is one of the highest reported to date. Homolog and congener patterns of PCDDs and PCDFs varied among species; hence, the results suggested that feeding habits, specific elimination, and metabolism influence contamination pattern. Concentrations of dioxin-like PCBs were in the order of granivores (32–83 ng/g) < predators [excluding mountain hawk eagle] (32–2,500 ng/g) < piscivore (61–12,000 ng/g) < omnivores (1,800–67,000 ng/g on a fat weight basis). Mountain hawk eagle contained the highest concentration of dioxin-like PCBs (55,000 ng/g fat weight). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalents (TEQs) ranged from 53–450,000 pg/g fat weight. 23478-PeCDF, 2378-TCDD/TCDF, and PCB congeners IUPAC 126 and 77 were major contributors to TEQs in birds. To our knowledge, this is the first study of PCDD/DFs and dioxin-like PCBs in livers of several species of Japanese birds. Received: 11 March 2001/Accepted: 5 August 2001     

Polychlorinated Dibenzo-p-Dioxins (PCDDs) and Dibenzofurans (PCDFs) in Muscle and Eggs of Salmonid Fishes from the Great Lakes

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in dorsal muscle and eggs of coho salmon, lake trout, and chinook salmon collected from Lakes Superior, Michigan, and Huron (Michigan waters). Absolute and relative concentrations of PCDDs and PCDFs varied among sampling locations (inter- and intralake) and fish species. Fish collected from Bay City (Saginaw Bay) contained the greatest concentrations of PCDDs and PCDFs both in muscle and eggs. Among the three fish species, chinook salmon accumulated greater concentrations than did coho salmon or lake trout. Concentrations of PCDFs were greater than those of PCDDs in all fishes. OCDF and TCDF were the predominant congeners of PCDF, whereas OCDD and TCDD concentrations predominated in PCDDs. Homolog compositions of PCDDs and PCDFs suggested the existence of multiple local sources in various locations. Concentrations of PCDDs and PCDFs in eggs of fishes were significantly correlated with those in muscle. Received: 2 May 1998/Accepted: 20 December 1998     

Investigation of a wood treatment facility: Impact on an aquatic ecosystem in the San Joaquin River, Stockton, California

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and metals were monitored in the river sediments near the McCormick and Baxter (MCB) wood treatment facility, Stockton, CA. Transplanted clams and resident fish species were used to assess bioavailability. The highest PCDD and PCDF contamination in sediments were confined to an area next to the facility and an area in the nearby Stockton harbor (DK location). Pentachlorophenol (PCP) wood treatment at MCB was the most probable source of the contamination. PCBs contaminated a wider area of the Stockton Ship Channel and harbor. Metal concentrations were uniformly low except for the metalloid arsenic in the Old Mormon Slough and lead and zinc near boat docks in the Stockton harbor. Despite high mortality rates, clams (Corbicula fluminea) bioaccumulated PCBs, PCDDs, and PCDFs. In clams, PCBs and 2,3,7,8 TCDD were much closer to equilibrium with the sediments than were higher chlorinated PCDDs and PCDFs. All fish were at background levels for 2,3,7,8 TCDD. All fish had lower lipid adjusted PCDD/F and PCB concentrations in the skinned muscle than in the whole fish. PCBs in fish were above background levels for United States river systems. Although high contamination exists in the river near this superfund site, adverse effects on the aquatic community could not be demonstrated.     

Historical Distribution of PCDDs, PCDFs, and Coplanar PCBs in Sediment Core of Ariake Bay, Japan

Persistent organic pollutants, particularly polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (co-PCBs) and toxic equivalent quantity (pg TEQ g⁻¹) were determined in sediment samples collected from Ariake Bay, Japan. The total concentration of PCDDs/DFs in surface sediment of the Yabe River (17,000 pg g⁻¹ dry wt) was approximately 2.5-fold higher than that of the Chikugo River (7,000 pg g⁻¹ dry wt) which has the highest flow amount of about 40% inputting to the northern Bay. The congener profile suggested that dioxin sources could be close to the study area. The PCDDs concentration (12,000 pg g⁻¹ dry wt) in the sediment layer, which was corresponding to the 1960s, was reflected on the pentachlorophenol (PCP) contamination occurring at that time in Ariake Bay. The reflecting of PCP in the sediment core was significantly considered by hierarchical cluster analysis. Based on isomer-specific analysis, the tetrachlorodibenzo-p-dioxin composition showed a gradual increase from 1978–1982 toward the surface, indicating that the pollution source at that period might be more influenced by chloronitrofen than PCP. This fact was supported, based on the ratio of ΣPCDD to ΣPCDF concentration. The PCDDs/DFs-derived TEQ contributed more than 90% of the ΣTEQ (PCDDs/DFs and co-PCBs) in all the detected sediment layers. The contribution of PCBs to the total TEQ was low; however, an increasing historical trend of concentration was clearly observed.     

Dioxins in agricultural soil of Poland

Total PCDDs concentration ranged from 6.8 to 41 pg g d.w. and for PCDFs from 3.9 to 19 pg/g d.w. with total toxic equivalency within a range 0.023-5.9 pg TEQ/g d.w. A somewhat elevated concentrations of PCDDs and PCDFs were found in the samples collected from the south of Poland in the vicinity of highly industrialized regions known for former extensive mining industry of hard coal and metallurgy, as well as for regions with high rates of urbanization in central Poland and in the vicinity of the western border of the country. Nevertheless, if consider homologue specific pattern of PCDDs and PCDFs no major differences were noted between spatially scattered sampling sites. In all samples highly chlorinated PCDDs/DFs dominated (12345678-OcCDD, 1234678-HpCDD, 12346789-OcCDF, 1234789-HpCDF, 1234678-HpCDF were found in all investigated soils). Their similar pattern can suggest that formation of these chemicals occur in similar conditions. Energy production and fossil fuel co-fired power boilers, chemical industry, metallurgical industry are probably the main sources in industrial regions, however heating of houses by small stoves and hard coal with added household wastes, and former use of agrochemical formulations consisting byimpurities of PCDD/F may also play important role at rural sites. The particularly elevated concentrations of OcCDF in some samples might be connected to the former production and use of highly chlorinated polychlorinated biphenyl formulation--Chlorofen.     

Chemical Characterization of Polychlorinated Biphenyls, -Dibenzo-p-Dioxins, and -Dibenzofurans in Technical Kanechlor PCB Formulations in Japan

Technical polychlorinated biphenyl (PCB) formulations—Kanechlor KC-200, KC-300, KC-400, KC-500, KC-600 and KC-1000—produced in Japan were analyzed for the chemical characterization of PCBs, -dibenzo-p-dioxins (PCDDs), and -dibenzofurans (PCDFs) using high-resolution gas chromatography–high-resolution mass spectrometry (HRGC-HRMS) by isotope dilution technique. The homologue/congener profiles of Kanechlor formulations resembled those of Clophen, Aroclor, and Delor, respectively, from Germany, the United States, and Czechoslovakia. Twenty-seven major PCB congeners contributed 50% (in KC-200) to 69–71% (in KC-600, 1000, and 500) to total PCBs. Average total PCB concentrations were 510,000, 800,000, 830,000, 840,000, 870,000, and 880,000 μg/g in KC-1000 (51%), KC-200 (80%), KC-500 (83%), KC-400 (84%), KC-300 (87%), and KC-600 (88%), respectively. Kanechlors also contained PCDDs and PCDFs (4.3 to 0.35 μg/g) as impurities which were approximately 1/10,000 to the PCB concentrations. Congener characterization and concentrations of PCBs and PCDFs were considerably varied in between Kanechlor formulations. The potential for the emissions of PCDDs and PCDFs from Kanechlor was estimated to be 1.94 kg and 464.4 kg, respectively. The average WHO-toxic equivalent (TEQ) was 16 (KC-500) >12 (KC-400) >10 (KC-1000) >4.1 (KC-600) >3.5 (KC-300) >1.9 (KC-200) on μgTEQ/g. Non- and mono-ortho PCBs were the major contributors to the total TEQ in Kanechlor formulations, whereas the PCDD/DF contribution was <2.0%. The environmental input of TEQs from Kanechlors can be estimated to be between 112 and 941 kg.     

Polychlorinated Dibenzo-p-dioxins, Dibenzofurans and Dioxinlike Biphenyls in Sediments from the Suzhou Creek, China

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) were detected in sediments from Suzhou Creek with mean concentrations of 478.1, 245.1, and 4727.6 pg/g dw, respectively. WHO–TEQ concentrations of PCDD/Fs in sediments ranged from 2.90 to 13.96 pg/g dw, while TEQ concentrations of PCBs varied from 0.27 to 1.41 pg/g dw. OCDD or HpCDD were the dominant congeners but PeCDF or HpCDD was the major contributor to PCDD/Fs-TEQ in all the sites. For dioxinlike biphenyls, PCB 118 was the major congener while PCB-TEQ was attributable to PCB 126 in all the samples.     

Chemometric comparisons of polychlorinated dibenzo-p-dioxin and dibenzofuran residues in surficial sediments from Newark Bay,New Jersey and other industrialized waterways

The distributions of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) measured in surficial sediments from the lower Passaic River and Newark Bay, New Jersey were compared to those observed in sediments from other waterways located within industrial or heavily populated areas using chemometric techniques. Comparisons were conducted using published data to determine whether the distributions of 2,3,7,8-substituted isomers in surficial sediments from industrialized waterways have similar or different fingerprint patterns. Chemometric evaluations consisted of principal components analysis and the complete linkage: farthest neighbor cluster method. The concentrations of individual isomers were normalized to the combined sum of the 2,3,7,8-substituted PCDD and PCDF isomer concentrations in order to evaluate relative distribution patterns. Several of the isomeric fingerprint patterns found in sediments from the lower Passaic River and Newark Bay were similar to those found in sediments from New Bedford Harbor, MA, USA, Black Rock Harbor, CT, USA, Providence River, RI, USA, Eagle Harbor, WA, USA, the Inner Stockholm archipelago, Sweden, Hamburg Harbor, Germany, and St. Laurensharbor, The Netherlands. Pattern differences were observed in sediments from Frierfjorden, Norway, Niagara River, NY, USA, and Chemieharbor, The Netherlands. The variations among the 2,3,7,8-substituted isomer patterns observed in different sediments were largely explained by the distributions of the higher chlorinated isomers. Other differences may be attributed to environmental conditions unique to each waterway such as tidal flux, shipping traffic, urbanization, sedimentation rates, and the presence of different industrial sources. Similarities in PCDD and PCDF patterns among the waterways were related to the presence of similar municipal and industrial sources, including effluents from pentachlorophenol and polychlorinated biphenyl manufacturing facilities, pulp and paper mills, automobile and shipping traffic, and municipal solid waste and industrial incinerators. The distributions of PCDDs and PCDFs in surficial sediments from some areas of the Newark Bay estuary were representative of those found in many industrialized regions. It wsa evident from this analysis that the application of chemometric analysis can be useful in characterizing the distribution of complex multi-constituent chemical residues and identifying sources of these compounds in freshwater, estuarine, and marine sediments.     

Polychlorinated Dibenzo-p-Dioxins, Dibenzofurans, and Dioxin-Like Polychlorinated Biphenyls in Sediment and Mussel Samples from Kentucky Lake, USA

Sediment and mussel tissues from the Kentucky Dam Tailwater (KDTW) and Ledbetter Embayment (LE) of Kentucky Lake, Kentucky, USA, were analyzed to examine the presence of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and non-, mono-, and di-ortho-chlorine-substituted polychlorinated biphenyls. Concentrations of target compounds varied with locations and sample matrices. In general, KDTW sediment samples contained slightly higher amounts of PCDD/DFs (average: 1100, range: 120-2400) than the LE sediments (average: 920, range: 580-1300) on a pg/g dry wt (dw) basis. Dioxin-like PCBs in KDTW were (average: 550, range: 70–2,000) higher than in LE (average: 320, range: 44-1000) on a ng/g dw basis. In contrast, mussel tissues had greater concentrations of PCDD/DFs in LE (average: 6500, range: 2200–13,000) than in KDTW (average: 3500, range: 2500-4800). Dioxin-like PCBs were slightly higher in KDTW (average: 76, range: 18–100) than in LE (average: 49, range: 24–96) on a ng/g fat wt basis. Biota sediment accumulation factors (BSAFs) were calculated using tissue concentrations and sediment concentrations based on dry weight. PCDD/DFs BSAF was in the range of 0.21-25 in LE and 0.093-13 in KDTW. 1,2,3,7,8,9-HxCDF in LE and 2,3,7,8-TCDF in KDTW had a greater BSAF, while BSAF for dioxin-like PCBs ranged from 0.84 to 13 in LE and from 2.3 to 12 in KDTW in which PCB-169 had the greatest BSAF in LE and PCB-167 in KDTW. Toxic equivalency (TEQ) was greatest in mussel from LE (mean: 193 pgTEQ/g fat wt) followed by mussel from KDTW (32 pgTEQ/g fat wt), sediment in KDTW (13 pgTEQ/g dry wt), and sediment in LE (7.6 pgTEQ/g dry wt). In general, PCDD/DF had a greater contribution to toxicity in mussels, while dioxin-like PCBs had a greater contribution to toxicity in sediment at both locations.     

A mixing model for polychlorinated dibenzo-p-dioxins and dibenzofurans in surface sediments from Newark Bay,New Jersey using polytopic vector analysis

The identity and relative contributions of various sources of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) to recently deposited sediments collected in Newark Bay and its major tributaries were determined using polytopic vector analysis (PVA), a multivariate statistical technique relatively new in the chemometric literature. The concentrations of 2,3,7,8-substituted PCDD/Fs were assayed in eighty-one surface and near-surface sediment samples collected from the Passaic River, Hackensack River, Arthur Kill, Elizabeth River, Kill Van Kull, Port Elizabeth, and Port Newark navigation channels and Robins Reef, which is located in New York Harbor. PVA modeling revealed five predominant 2,3,7,8-substituted PCDD/F fingerprint patterns in geographically plausible distributions throughout the estuary. This was consistent with the current understanding of hydrodynamic and sedimentation conditions reported in the literature for Newark Bay. Three patterns contained 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), which is alleged to originate from a single industrial source on the lower Passaic River. One of the fingerprints containing 2,3,7,8-TCDD was present in moderate proportions (10–20%) in surface sediments near the site, but was generally observed in low abundance (<5%) elsewhere in the estuary. A fingerprint pattern characteristic of PCDD/F profiles in effluents from municipal sewage and waste water treatment plants was widely distributed in the estuary, but reached its highest relative proportions in the Elizabeth River. A third fingerprint pattern was highest in the Arthur Kill and lower Passaic River and closely matched the residue patterns found in several types of combustion sources. A fourth finger-print pattern in Hackensack River and lower Passaic River sediment matched the PCDD/F profile reported in PCB Aroclor^® formulations. A fifth fingerprint pattern matched the profile in recycled pulp and paper mill effluents and was highest in Kill van Kull and upper Passaic River sediment. The majority of PCDD/Fs in sediment from Reaches B, C, and D of Port Newark and Port Elizabeth were attributable to sediments transported via the Arthur Kill and the Kill Van Kull. These results are consistent with those previously reported using principal components analysis, which indicated that 2,3,7,8-substituted PCDD/F patterns in the sediments of Newark Bay are consistent with discharges from multiple sources.     

Congener-specific characterization and sources of polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls in marine sediments from industrialized bays of Korea

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DLPCBs) were determined in 122 coastal sediments from heavily industrialized areas in Korea. Toxic equivalent (TEQ) concentrations of PCDD and PCDF (PCDD/F) and DLPCB ranged from 0.44 to 38.5 pg/g dry weight and from 0.01 to 38.4 pg/ g dry weight, respectively. Overall PCDD/F and DLPCB concentrations were elevated in estuarine and inner bay locations close to industrial complexes, indicating that these contaminants derived from local discharges. Concentrations of PCDD/F measured in the present study were comparable to those in industrialized areas of other countries. Nonparametric multidimensional scaling ordination and congener-specific characterization showed that combustion processes occurring in industrial complexes, including the steel industry, are the major source of PCDD/Fs in Korean coastal waters. There were no significant correlations among PCDD/ Fs, DLPCBs, and total organic carbon; however, there was moderate correlation between PCDD/Fs and DLPCBs in some coastal bays, suggesting that these chemicals have similar sources and movements in these locations.     

Principal components analysis of potential sources of polychlorinated dibenzop-dioxin and dibenzofuran residues in surficial sediments from Newark Bay,New Jersey

The distributions of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) measured in surficial sediments from the lower Passaic River and Newark Bay, New Jersey, USA, were compared to those reported in various industrial process residues and effluents, contaminated soils, chemical formulations, and municipal waste disposal activities that are known or suspected to be sources of these compounds in the aquatic environment. Comparisons were conducted using data from published literature to determine whether the composition of tetra through octachlorinated congeners and 2,3,7,8-substituted residues reported in a broad range of potential environmental sources could explain the presence of these compounds in Newark Bay. Pattern similarities and differences between congener groups and isomers were obtained by principal components analysis. The congener and isomer fingerprint patterns found in surficial sediments appear to be the result of releases from several industrial and municipal sources commonly found in heavily industrialized and populated urban environments, including municipal sewage sludge, municipal solid waste incinerator fly ash, pentachlorophenol, sodium pentachlorophenate, newsprint, scrap metal reclamation incinerators, combustion engines, and pulp and paper mill black liquor recovery furnaces. The variations among the PCDD and PCDF residue and congener patterns were largely explained by the distributions of the hexa- and octachlorinated compounds and by 2,3,7,8,-TCDD, 2,3,7,8,-TCDF, and the penta-substituted isomers. Although it has been claimed that a single industrial source is responsible for the presence of these compounds in the sediments of Newark Bay, the available evidence indicates that the vast majority of the PCDDs and PCDFs are the result of contributions from several industries. There is no evidence from this analysis to indicate that a single source is responsible for the contamination.     

PCDDs, PCDFs, and PCBs in human blood in relation to consumption of crabs from a contaminated Fjord area in Norway.

Consumption of fish and shellfish from contaminated areas may be an important source of human exposure to persistent organohalogen compounds such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). We determined concentrations of 2,3,7,8-substituted PCDDs and PCDFs and 19 PCB congeners in whole blood samples from three groups of men, 40-54 years of age, with different consumption levels of crabs from a fjord area in southern Norway polluted with organochlorine compounds from a magnesium production plant. A significant increase of many PCDD/PCDF congeners was found in the blood when comparing the referents, moderate-, and high-intake groups. The greatest difference was observed for several of the PCDFs that are characteristic for the contamination of the marine biota of the fjord. PCBs, in general, play a minor role in the contamination of the fjord by the magnesium production process, except for the highly chlorinated congeners such as PCB-209. Nevertheless, almost all PCBs increased from the referents to the high-intake group. However, the relative concentrations of several highly chlorinated PCBs (particularly PCB-209) in blood are unexpectedly low compared to their abundance in crabs, indicating low uptake of these congeners. The exposure to PCDDs/PCDFs from crab consumption calculated from individual body burdens of these compounds were in good agreement with the intake estimated from previously measured concentrations in crabs, reported fishing sites, and consumption. Almost all subjects in the high-intake group exceeded the tolerable weekly intake of 35 pg TEQ/kg body weight/week proposed by a Nordic Expert Group.     

Dietary- and tissue-based exposure of belted kingfisher to PCDFs and PCDDs in the Tittabawassee River floodplain, Midland, MI, USA

Concentrations of polychlorinated dibenzofurans (PCDFs) and other dioxin-like compounds in soils and sediments of the Tittabawassee River and associated floodplains downstream of Midland, Michigan, USA, are greater than upstream sites. As a result of these concentrations, which are some of the greatest ever reported, a site-specific exposure assessment of belted kingfisher breeding in the assessment area was conducted. To reduce the uncertainty associated with predicting exposure from abiotic matrices, concentrations of residues were quantified in site-specific prey items and in eggs and nestlings of belted kingfisher. Dietary exposure, expressed as the potential average daily dose, based on site-specific concentrations of PCDFs, polychlorinated dibenzo-p-dioxins (PCDDs), and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQ(WHO-Avian)) in prey items was consistently greater along the Tittabawassee River than in associated reference areas and further downstream sites in the Saginaw River. Concentrations of PCDD/DFs in eggs and nestlings of belted kingfisher varied among sampling areas, being greater in both eggs and nestlings nesting along the Tittabawassee River compared to those of belted kingfisher from upstream reference areas. Geometric mean concentrations of PCDD/DFs were 130 and 200 ng/kg wet weight in eggs and nestlings of belted kingfisher, respectively. These concentrations are the equivalent of 84 and 95 ng TEQ(WHO-Avian)/kg. Site-specific biomagnification factors for select PCDD/DF congeners ranged from <1.0 to 1.8 in belted kingfisher.     

Birth weight and sex of children and the correlation to the body burden of PCDDs/PCDFs and PCBs of the mother.

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) were analyzed in 167 random human milk samples from urban and rural areas in Finland. Dietary habits and background information on each mother and child were gathered by questionnaire. Body mass indexes (BMI) before pregnancy and delivery in the rural area were 5-10% higher than in the urban area, but fat content of mother's milk was about 10% higher in the urban area. The mean weights of children (+/- standard deviation) were similar in the rural and urban areas among primiparae, 3,500 +/- 597 g and 3,505 +/- 454 g, respectively, although dioxin international toxic equivalents (I-TEQs) were significantly higher in the urban area. The mother's level of education did not affect the weight of the child, but concentrations of PCDDs/PCDFs (I-TEQ, 2,3,4,7,8-Cl5 dibenzofuran,1,2, 3,7,8-Cl5 dibenzodioxin) and PCBs [sum of PCBs (sumPCB), PCB-TEQ, and most PCB congeners] increased with advanced education. This is considered to be due to differences in the mother's consumption of fish. The birth weight, especially of boys, slightly decreased with increasing concentrations of I-TEQ, 2,3,4,7,8-Cl5 dibenzofuran, 1,2,3, 7,8-Cl5 dibenzodioxin, and 2,3,7,8-Cl4 dibenzodioxin; however, when the analysis was restricted to primiparae, there was no statistically significant correlation between birth weight and the concentrations of PCDDs/PCDFs. No correlation was found between the weight of the child and PCBs, PCB-TEQs, or individual PCB congeners in the whole material or among primiparae, or among boys or girls. The concentrations of PCDDs/PCDFs and PCBs inhuman milk were modeled for primiparae by weighing fish consumption, age of mother, milk fat content, and BMI before pregnancy. The linear regression resulted in values of R = 0.67 and 0.30 for the modeled dioxin I-TEQs in the urban and rural areas, respectively, and the corresponding values for sumPCBs of R = 0.60 and 0.11. The increase of PCDD/PCDF body burden was calculated to be on average 0.58 pg I-TEQ/g milk fat/year in the urban area and 0.39 pg I-TEQ/g milk fat/year in the rural area.     

Dioxins and dibenzofurans in adipose tissue of the general US population and selected subpopulations.

OBJECTIVES. The Environmental Protection Agency's National Human Adipose Tissue Survey (NHATS) was conducted in fiscal year (FY) 1987 to (1) estimate average concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in the adipose tissue of humans in the US population, (2) identify differences in average concentrations among subpopulations, and (3) compare average concentrations with those from the FY 1982 NHATS. METHODS. Population estimates of the average levels of PCDDs and PCDFs were established on the basis of 865 human adipose tissue specimens collected in FY 1987. Average levels among subpopulations were compared. RESULTS. The average concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin in the adipose tissue of the US population was 5.38 pg/g, increasing from 1.98 pg/g in children under 14 years of age to 9.40 pg/g in adults over 45. The effect of age was significant for nine compounds. Regional differences in the levels of 2,3,4,7,8-pentachlorinated dibenzofurans were statistically significant, but there were no significant differences associated with sex or race. CONCLUSIONS. The survey provides a baseline of average levels of PCDDs and PCDFs in the adipose tissue of humans in the US population.