Determination of partition coefficients of chlorinated phenols,guaiacols and catechols by shake-flask GC and HPLC

The logarithm of the partition coefficients in the n-octanol-water system, log P, of 21 chlorinated phenols, guaiacols and catechols are determined, by both shake-flask gas chromatography (GC) and high pressure liquid chromatography (HPLC). In the shake-flask GC method, the water phase, after equilibration with spiked octanol, was analysed by glass capillary GC with electron capture detection. The relative responses of individual phenols were compared with those from before partition, and the partition coefficients were calculated. In the HPLC method, the capacity factors were used for calculating the log P values by calibration using four chlorophenols with known log P values. The use of short columns with 3 μm packing materials, combined with amperometric detection, offers fast and sensitive determinations.The results from both these methods have high precision, and agree well with the values calculated according to Hansch (1). The small deviations between the results obtained by shake-flask GC and HPLC for the compounds which have high dipole moments can be explained by the influence of different dipole moments and hydrogen bonding affinities in the solute-solvent and solute-stationary phase interactions. Compared with these interactions, the salt effect for concentrations lower than 1 M sodium chloride is negligible.     

Isomer specific syntheses of chlorinated catechols and guaiacols relevant to pulp bleaching

A variety of chlorinated catechols and guaiacols relevant to pulp bleaching were synthesized by employing fundamental differences in the acidities of phenolic hydroxyl groups in chlorinated catechols, and directive effects in guaiacols.     

Polychlorinated biphenyls (PCBs) in the British environment: sinks, sources and temporal trends

This paper estimates the present UK environmental loading of polychlorinated biphenyls (PCBs). Of the estimated approximately 40,000 t SigmaPCB sold in the UK since 1954, only an estimated 1% (400 t) are now present in the UK environment. Comparisons of estimated production and current environmental loadings of congeners 28, 52, 101, 138, 153 and 180 suggest that PCB persistence broadly increases with increasing chlorination. Those PCBs that are not now present in the UK environment are considered to have been destroyed--by natural or anthropogenic mechanisms, to be still in use, to reside in landfills or to have undergone atmospheric and/or pelagic transport from the UK. The dramatic fall in PCB levels in archived UK soils and vegetation between the mid-1960s and the present is evidence that the latter mechanism is the most important and that a significant proportion of PCBs released into the UK environment in the 1960s have subsequently undergone environmental transport away from the UK. The bulk (93.1%) of the estimated contemporary UK environmental burden of SigmaPCBs is associated with soils, with the rest found in seawater (3.5%) and marine sediments (2.1%). Freshwater sediments, vegetation, humans and sewage sludge combined account for 1.4% of the present burden, whilst PCB loadings in air and freshwater are insignificant. Although consideration of individual congeners does not reveal any major deviations from the relative partitioning of Sigma PCBs, the importance of sinks other than soils is enhanced for individual congeners, particularly 138 and 180. In particular, around 2% of the total UK burden of congener 180 is present in humans, implying that biodata as a whole may constitute an important sink for the higher chlorinated congeners. The contemporary flux of SigmaPCBs to the UK surface is estimated at 19 t yr(-1), compared with an estimated annual flux to the atmosphere of 44-46 t. This implies that the major sources of PCBs to the UK atmosphere have been identified and that there is currently a net loss of these compounds from the UK. These sources are: volatilisation from soils (88.1%), leaks from large capacitors (8.5%), the production of refuse-derived fuel (RDF) (2.2%), leaks from transformers (0.6%), the recovery of contaminated scrap metal (0.5%) and volatilisation from sewage sludge-amended land (0.2%). Interestingly, whilst large excesses of estimated annual fluxes to the atmosphere over deposition fluxes for individual congeners exist for congeners 28, 52 and 101, estimates of fluxes in both directions across the soil-atmosphere interface agree closely for congeners 138, 153 and 180. This suggests that lower chlorinated congeners are more susceptible to both long-range environmental transport beyond the UK and to atmospheric degradation. Retrospective analysis of dated sediment cores, vegetation and soils indicates that environmental transport from North America and continental Europe introduced PCBs into the British environment well before the onset of their commercial production in the UK in 1954. Since that time, the input of PCBs to the UK environment has essentially reflected temporal trends in UK use. After peaking in the 1960s they declined rapidly through the 1970s following restrictions on PCB use. Recent evidence, however, is that the rate of decrease has diminished and that further significant reductions in fresh environmental input will take some time to occur. Such reductions will be especially slow for humans and other biota with long life-spans. This stems partly from cross-generational transfer from parents to offspring and also because the persistence of PCBs in biota means that present body burdens will reflect past as well as current exposure.     

Chlorinated guaiacols and catechols bioaccumulation potential in bleaks (Alburnus alburnus, Pisces) and reproductive and toxic effects on the har-pacticoid Nitocra spinipes (Crustacea)

The bioaccumulation potential in bleaks (Alburnus alburnus, Pisces) and acute toxic and reproductive effects on Nitocra spinipes (Crustacea), of 4,5,6-trichloroguaiacol (I), tetrachloroguaiacol (II) and tetrachlorocatechol (III) was investigated. Continuous flow tests with I and II (10 μg/l) gave a rapid bi-phasic uptake in the fish with I and II reaching a level of 4 μg/g fresh weight after 14 d. An equally rapid excretion was determined with the detection limit of I and II being reached after 10 days in pure water. The 96-h LC50 values for I, II and III to N. spinipes was determined to 5.2, 3.9 and 3.3 mg/l, respectively, in static tests. The fecundity of N. spinipes was reduced to 50 % of the control values at 37±6 and 54±4 μg/l (II) per liter in static and continuous flow tests, respectively.     

Polychlorinated biphenyls in the Kupa River, Croatia, Yugoslavia

The presence of polychlorinated biphenyls (PCBs) was investigated in samples of water, suspended particles, sediments and fish from the Kupa river, Croatia, Yugoslavia, along a river stretch extending up to 10 km upstream and 200 km downstream of the primary contaminated karst region. Contamination was due to improper disposal of industrial waste discharge. The PCB levels detected in the samples collected downstream ranged from 1 to 52 ng 1⁻¹ for water, from 50 to 190 μg kg⁻¹ for suspended particles and from 8 to 39 μg kg⁻¹ for the sediment. A wide range of PCB concentrations, from 0.1 to 42.3 μg g⁻¹, which were measured in edible portions of different fish confirmed a long-term contamination of the river with PCBs. As the Kupa may be classified among low to moderately contaminated waters, it is essential that the investigations of the presence and behaviour of PCBs in the river and its environment be continued.     

Polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in the general population in Finland

We measured adipose tissue concentrations of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs) in 420 general Finns living in southern Finland. The mean (median) concentrations of WHO(PCDD/F)-TEQ and WHO(PCB)-TEQ were 29.0 (24.1) and 20.7 (16.7) pg g-1 fat, respectively. The concentrations clearly correlated with age. Expressing the concentrations as a function of subject's ages revealed that the exposure of Finns has declined over the last 30 years. A downward gradient was found in the concentrations from the Baltic Sea coast to inland areas in Finland, and this was assessed to be due to consumption of the Baltic Sea fish, especially Baltic herring. Linear regression models for natural logarithm WHO(PCDD/F)-TEQ, natural logarithm WHO(PCB)-TEQ, and natural logarithm WHO(total)-TEQ, explained 70%, 69%, and 72% of the variability, respectively. Age, lactation, place of residence, and fish consumption frequencies were significant predictors in the models.     

Formation of chlorinated phenols, dibenzo-p-dioxins, dibenzofurans, benzenes, benzoquinnones and perchloroethylenes from phenols in oxidative and copper (II) chloride-catalyzed thermal process

Formation of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and chlorinated phenols on CuCl(2) from unsubstituted phenol and three monochlorophenols was studied in a flow reactor over a temperature range of 100-425 degrees C. Heated nitrogen gas streams containing 8.0% oxygen were used as carrier gas. The 0.00024mol of unsubstituted phenol and 0.00039mol of each monochlorophenol were passed through a 1g and 1cm SiO(2) particle containing 0.5% (Cu by mass) CuCl(2). Chlorination preferentially occurred on ortho-(2, 6) and para-(4) positions. Chlorination increased up to 200 degrees C, and thereafter decreased as temperature increased. Chlorination of phenols plays an important role in the formation of the more chlorinated PCDD/Fs. Chlorinated benzenes are formed possibly from both chlorination of benzene and chlorodehydroxylation of phenols. Chlorinated phenols with ortho chlorine formed PCDD products, and major PCDD products were produced via loss of one chlorine. For PCDF formation, at least one unchlorinated ortho carbon was required.     

Phytoremediation of polyaromatic hydrocarbons, anilines and phenols

Phytoremediation technologies based on the combined action of plants and the microbial communities that they support within the rhizosphere hold promise in the remediation of land and waterways contaminated with hydrocarbons but they have not yet been adopted in large-scale remediation strategies. In this review plant and microbial degradative capacities, viewed as a continuum, have been dissected in order to identify where bottle-necks and limitations exist. Phenols, anilines and polyaromatic hydrocarbons (PAHs) were selected as the target classes of molecule for consideration, in part because of their common patterns of distribution, but also because of the urgent need to develop techniques to overcome their toxicity to human health. Depending on the chemical and physical properties of the pollutant, the emerging picture suggests that plants will draw pollutants including PAHs into the plant rhizosphere to varying extents via the transpiration stream. Mycorrhizosphere-bacteria and -fungi may play a crucial role in establishing plants in degraded ecosystems. Within the rhizosphere, microbial degradative activities prevail in order to extract energy and carbon skeletons from the pollutants for microbial cell growth. There has been little systematic analysis of the changing dynamics of pollutant degradation within the rhizosphere; however, the importance of plants in supplying oxygen and nutrients to the rhizosphere via fine roots, and of the beneficial effect of microorganisms on plant root growth is stressed. In addition to their role in supporting rhizospheric degradative activities, plants may possess a limited capacity to transport some of the more mobile pollutants into roots and shoots via fine roots. In those situations where uptake does occur (i.e. only limited microbial activity in the rhizosphere) there is good evidence that the pollutant may be metabolised. However, plant uptake is frequently associated with the inhibition of plant growth and an increasing tendency to oxidant stress. Pollutant tolerance seems to correlate with the ability to deposit large quantities of pollutant metabolites in the 'bound' residue fraction of plant cell walls compared to the vacuole. In this regard, particular attention is paid to the activities of peroxidases, laccases, cytochromes P450, glucosyltransferases and ABC transporters. However, despite the seemingly large diversity of these proteins, direct proof of their participation in the metabolism of industrial aromatic pollutants is surprisingly scarce and little is known about their control in the overall metabolic scheme. Little is known about the bioavailability of bound metabolites; however, there may be a need to prevent their movement into wildlife food chains. In this regard, the application to harvested plants of composting techniques based on the degradative capacity of white-rot fungi merits attention.     

Polychlorinated biphenyl residues in sandstorm depositions in Beijing, China

Sandstorms, which distribute many particles, are a special atmospheric occurrence and are frequent in northern China. We conducted this study to determine, for the first time, the concentration of polychlorinated biphenyls (PCBs) in sandstorm depositions. We collected 13 samples from urban areas of Beijing, and we measured a total of 144 PCB congeners. Thirteen samples all contained PCB residues. The total PCB concentration ranged from 1.6 to 15.6ngg(-1) (median, 4.8ngg(-1), dry weight), with trichlorinated biphenyls as the predominant homologue (>50.4%). Furthermore, we observed increasing PCB contamination from northwest to east Beijing. We later explored possible factors affecting contamination of the sandstorm depositions, which revealed a significant correlation between SigmaPCBs and the minimum particle size of the sandstorm deposition samples. Principal-component analysis revealed that the major source of PCBs in Beijing may be potentially associated with the number-one commercial PCB through the long-range transmission. In previous results, PCBs were not a severe component of contamination in sandstorm depositions of Beijing. However, this study suggested that sandstorm deposition may be a potential source of exposure to PCBs for the residents of Beijing, China.     

Polychlorinated dibenzo-p-dioxins, -dibenzofurans, and biphenyls in domestic animal food stuff and their fat

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzo-p-dioxins (PCDFs) and dioxin-like coplanar PCBs and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) were measured in domestic animal related samples such as feed ingredient, mixed feed and animal fat from Japan. The mean concentration of total PCDDs, PCDFs and coplanar PCBs in fish oil was 17000pg g-1 lipid wt, which 9- to 30-fold greater than that from other animal originated ingredients. Mixed feed for chicken and chicken fat contained greater total PCDDs, PCDFs, coplanar PCBs concentrations (190 and 2100pg g-1 lipid wt) compared to those for pig (120 and 320pg g-1 lipid wt). WHO-TEQs were ranged 0.39-13, 0.15-0.22 and 0.73-2.8pg g-1 lipid wt for ingredients, mixed feeds and animal fats, respectively. Greater biomagnification factor was noticed for congeners 1,2,3,7,8-PeCDD, 1,2,3,6,7,8-HxCDD, 2,3,7,8-TCDF and 1,2,3,4,7,8-HxCDF in chicken and pig fat. Biomagnification factors for both mono- and non-ortho coplanar PCBs were greater in chicken fat compared to those in pig fat.     

Polychlorinated naphthalenes in sediments from the Venice and Orbetello lagoons, Italy

The purpose of this study was to evaluate the contamination caused by polychlorinated naphthalenes in two polluted Mediterranean lagoons. Surface sediment samples from Venice and Orbetello lagoons were analysed using HRGC-HRMS. The levels of the sum of mono- to octa-CN ranged from 0.03 to 1.51 ng/g. Differences in PCN levels were observed as a function of the sampling site, with levels at the industrial sites exceeding those at the control sites. Although the PCN patterns and profiles resembled one another in different sediment samples, they differed considerably when compared with those in the technical PCN formulation Halowax 1014.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in paddy soils and river sediments in Akita, Japan

Paddy soils and sediments from the Yoneshirogawa, Omonogawa, and Koyoshigawa River Basins in Akita were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). The levels and compositions in those samples including soils from non-agricultural areas (non-agricultural soils) were investigated using isomer-specific analysis to determine characteristic sources. The PCDD/PCDF compositions in the samples were compared with respect to possible sources. The PCDD/PCDF concentrations in paddy soils were much higher than those in the non-agricultural soils and much higher than those found in other parts of Japan. Although PCDD/PCDFs were ubiquitous in sediments from river sources to mouths of the respective river basins, those concentrations were much lower than those from paddy soils and non-agricultural soils, and from other parts of Japan. Comparison of PCDD/PCDF homologues and isomer compositions for samples indicated that compositions of paddy soils and sediments, except for those from river sources, had similar characteristics to PCDD/PCDFs originating from impurities in herbicides, 2,4,6-trichlorophenyl 4-nitrophenyl ether (CNP) and pentachlorophenol (PCP), and that compositions of river-source sediments and non-agricultural soils resembled those of atmospheric depositions. Results of statistical analyses suggest that PCDD/PCDF contamination of paddy soils and sediments is attributable mainly to three sources: CNP, PCP, and atmospheric deposition. Results of this study also demonstrate that CNP and PCP are not only important contaminants of local areas of Japan, but that they exist throughout Akita, in northern Japan. We therefore conclude that PCDD/PCDF pollution caused by those compounds has a widespread influence on paddy soils and river sediments in Japan.     

Polychlorinated dibenzo-p-dioxins,dibenzofurans and polychlorinated biphenyls in polar bear,penguin and south polar skua

Concentrations of 2378-substituted polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (DFs) and non- and mono-ortho-substituted polychlorinated biphenyls (dioxin-like PCBs) were measured in livers of polar bears from the Alaskan Arctic and in eggs of Adelie penguin and south polar skua and weddell seal liver, fish and krill from Antarctica. This is one of the first reports to document the concentrations of PCDDs/DFs in polar bear livers from Alaska, and in penguin and skua eggs from Antarctica. Concentrations of total PCDD/DFs in livers of polar bears ranged from 8 to 66 (mean: 26) pg/g, on a lipid weight basis. Concentrations of total PCDD/DFs in Antarctic samples were in the increasing order on a lipid weight basis; weddell seal liver (8.9 pg/g) < fish (11-17 pg/g) < krill (27 pg/g) > penguin eggs (30 ng/g) > seal liver (57 ng/g) > fishes (6.2 ng/g) > krill (0.9 ng/g). Concentrations of 2378-tetrachlorodibenzo-p-dioxin equivalents (TEQs) calculated based on the WHO TEFs were higher in the eggs of polar skua (mean: 344: range: 220-650 pg/g, lipid wt.) from Antarctica than in polar bear livers from Alaska (mean: 120; range: 69-192 pg/g). In general, concentrations of PCDFs were greater than those of PCDDs in polar organisms. 23478-PeCDF is one of the dominant congener found in several samples. Concentrations of TEQs in polar bear livers and skua eggs were close to those that may cause adverse health effects. Dioxin-like PCBs, particularly, non-ortho coplanar PCBs were the major contributors to TEQ concentrations in penguin and skua eggs whereas mono-ortho PCBs accounted for a major portion of TEQs in polar bear livers.     

Polychlorinated naphthalenes in human adipose tissue from New York, USA

Polychlorinated naphthalenes (PCNs) are persistent, bioaccumulative, and toxic contaminants. Prior to this study, the occurrence of PCNs in human adipose tissues from the USA has not been analyzed. Here, we have measured concentrations of PCNs in human adipose tissue samples collected in New York City during 2003-2005. Concentrations of PCNs were in the range of 61-2500 pg/g lipid wt. in males and 21-910 pg/g lipid wt. in females. PCN congeners 52/60 (1,2,3,5,7/1,2,4,6,7) and 66/67 (1,2,3,4,6,7/1,2,3,5,6,7) were predominant, collectively accounting for 66% of the total PCN concentrations. Concentrations of PCNs in human adipose tissues were 2-3 orders of magnitude lower than the previously reported concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Concentrations of PCNs were not correlated with PCB concentrations. The contribution of PCNs to dioxin-like toxic equivalents (TEQs) in human adipose tissues was estimated to be <1% of the polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F)-TEQs.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in plywood combustion gas

Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/DF) levels in plywood combustion gas were investigated for the effects of ammonium chloride (NH4Cl) and paint. For combustion systems in which neither NH4Cl nor paint were present in the plywood samples, total amounts of PCDD/DFs in the combustion gas were in the order of 35-529 ng/Nm3, and were higher in the systems with softwood trees than broadleaf ones, depending on the Cl concentrations. For the systems with added NH4Cl and no paint, and those without NH4Cl but were painted, higher PCDD/ DF rates were observed at combustion temperatures of 270 degrees C and 500 degrees C, respectively. However, for the systems with both NH4Cl and paint, their amounts in the range of 0.6-13 ng/Nm3 were the lowest in all systems. The PCDD/DF abundance profiles were similar to their patterns in pentachlorophenol (PCP). Furthermore, it was found that the 2,3,7,8-chlorine substituted penta- and hexa-CDDs contributed more than other 2,3,7,8-chlorine substitutes to toxicity equivalency (TEQ).     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in soils and sediments from Daliao River Basin, China

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) were analyzed in surface sediments and top soils collected from 30 sites in Daliao River Basin. The concentrations of PCDD/F ranged from 0.28 to 29.01 ng TEQ kg(-1) dw (mean value, 7.45 ng TEQ kg(-1)dw) in sediments, and from 0.31 to 53.05 ng TEQ kg(-1)dw (mean value, 7.00 ng TEQ kg(-1)dw) in soils. PCDD/F pollution in sediments from the mid- and downstream sections of Hun River was found to be relatively heavy, and the levels of PCDD/F contamination in paddy soils were generally higher than those of upland soils. Using multivariate statistical analysis, the PCDD/F homologue and congener profiles of all soil and sediment samples were compared with those of suspected PCDD/F sources. The results showed that, PCDD/F contamination in most sediments of Hun River should mainly originated from the production of organochlorine chemicals, while metal smelting was the important potential source of PCDD/F in the drainage area of Taizi River. PCDD/F contamination in paddy soils should be simultaneously attributed to the polluted water irrigation and the organochlorine pesticide application.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in River Po sediments

The River Po is the main Italian river draining one of the most populated and industrialised regions in Italy. As part of a monitoring project to assess environmental quality in the River Po, we measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in bottom sediments collected along the whole course of the river, from the spring to the delta, downstream from the confluence of its main tributaries. The aim was to investigate the level of contamination in the main Italian river and the contribution of contaminant loads from the subbasins. Composite sediment samples were collected in summer and winter surveys in low-flow water conditions and analysed by HRGC-HRMS for PCDD and PCDF homologue groups and for the 2,3,7,8-substituted congeners. The spatial trend observed in the Po River for PCDD and PCDF concentrations varied depending on the load of contaminants received from the tributaries and the processes of sedimentation. The sum of PCDD and PCDF concentrations, and the toxic equivalent content, ranged from 121 to 814 and from 1.3 to 13 ng/kg dry weight sediment, respectively. These levels of contamination seem lower than in the sediments of rivers draining highly industrialised areas. The PCDD and PCDF homologue profiles in all the samples were very similar, suggesting a common source of this contamination in the River Po. Principal component analysis suggested that widespread sources, such as urban runoff and domestic wastewaters, are probably the main cause of these levels of PCDDs and PCDFs.     

Polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in rice straw smoke and their origins in Japan

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) contained in the smoke generated from rice straw burning in post-harvest paddy fields in Japan were analyzed to determine their congener profiles. Both the apportionment of toxic equivalent (TEQ) by using indicative congeners and the comparison of the homolog profiles showed that the PCDDs/PCDFs/DL-PCBs present in the rice-straw smoke were greatly influenced by those present as impurities in pentachlorophenol (PCP) and chlornitrofen (CNP, 4-nitrophenyl-2,4,6-trichlorophenyl ether) formulations that had been widely used as herbicides in paddy fields in Japan. Further, in order to investigate the effects of paddy-field soil on the PCDDs/PCDFs/DL-PCBs present in rice-straw smoke, PCDD/PCDF/DL-PCB homolog profiles of rice straw, rice-straw smoke and paddy-field soil were compared. Rice-straw smoke was generated by burning rice straw on a stainless-steel tray in a laboratory. The results suggested that the herbicides-originated PCDDs/PCDFs/DL-PCBs and the atmospheric PCDDs/PCDFs/DL-PCBs contributed predominantly to the presence of PCDDs/PCDFs/DL-PCBs in the rice-straw smoke while the contribution of PCDDs/PCDFs/DL-PCBs formed during rice straw burning was relatively minimal. The major sources of the PCDDs/PCDFs/DL-PCBs found in the rice-straw smoke were attributed primarily to the paddy-field soil adhered to the rice straw surface and secondarily to the air taken by the rice straw. The principal component analysis supported these conclusions. It is concluded that rice straw burning at paddy fields acts as a driving force in the transfer of PCDDs/PCDFs/DL-PCBs from paddy-field soil to the atmosphere.     

Polychlorinated dibenzodioxins and polychlorinated dibenzofurans in sewage sludges

A municipal sewage sludge from Syracuse, New York and a largely domestic sludge from Sodus, New York were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) using combined gas chromatography and high resolution mass spectrometry (GC/HRMS). Concentrations in ppt of the following PCDDs were found in the syracuse sludge: tetrachlorodibenzo-p-dioxins (TCDDs), 150, hexachlorodibenzo-p-dioxins (HxCDDs), 2100, heptachlorodibenzo-p-dioxins (HCDDs), 6300, octachlorodibenzo-p-dioxins (OCDDs), greater than 60,000. The following ppt concentrations were found in the Sodus sludge: TCDDs, 7200, HxCDDs, 300, HCDDs, 900, OCDDs 7500. The TCDD was a single but not the highly toxic 2,3,7,8-isomer. PCDFs were mostly nondetectable in the sludges. The toxicology and potential for environmental contamination by these compounds are discussed.