Accumulation of metals,polychlorinated biphenyls,and polycyclic aromatic hydrocarbons in sediments from the lower Passaic River,New Jersey

Thirteen sediment cores of 1.5–6 m depth were collected from the lower Passaic River in Newark, New Jersey and assayed for metals, total petroleum hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and Aroclor^® and coplanar polychlorinated biphenyls (PCBs). Chronological profiles of chemical concentrations at specified depths and sediment accumulation rates in each core were determined by ¹³⁷Cs and ²¹⁰Pb radioisotope measurements. Temporal concentrations of these chemicals were compared to available benchmark sediment toxicity values to assess historic and current toxic hazards to aquatic organisms. Elevated concentrations of several metals, including copper, lead, mercury, nickel, and zinc, were found in surface and buried sediments at concentrations that greatly exceeded Long and Morgan (1991) Effects Range-Low (ER-L) and Effects Range-Median (ER-M) values. Aroclors^® 1242, 1248, and 1254 and several PAHs were also found at concentrations exceeding Long and Morgan (1991) benchmark toxicity values. In general, the highest metal and PAH concentrations were found in sediment deposited prior to the 1960s. Elevated PCB concentrations were found in sediment deposited between 1950 and 1980. The results indicate that the lower Passaic River is heavily contaminated due to recent and historical municipal and industrial discharges from local and up-stream sources. The primary sources of PCBs, PAHs, and metals appear to be discharges of industrial effluents either directly into the waterway or through combined sewer overflows. Additional inputs are probably from urban runoff entering through combined sewer overflows and storm drains.     

Are datascreen terminals a source of increased PCB-concentrations in the working atmosphere?

Summary The use of polychlorinated biphenyls (PCBs) is restricted to closed systems. They are thus still used as dielectric fluids in capacitors and transformers. The hypothesis that skin rashes and excema reported among datascreen operators might be caused by leakage of PCB from components in the screen terminals was investigated. No information about the chemical content of the electrical components in the actual datascreen terminals were available. The PCB-concentration in the atmosphere in a workplace where such skin reactions had previously occurred was therefore determined.Air was sampled through 2 or 3 days, during work hours only. A glass fiber backed by an Amberlite XAD-2 column was used to trap the sample. The total level of PCBs in this sample was analysed by glass-capillary gas chromatography with electron capture detection. Commercial PCB mixtures were used as standards.PCB-concentrations in the working atmosphere (56–81 ng/m³) were about 50–80 times the level of PCB in samples collected outside the building. Indoor and outdoor samples differed also qualitatively. The indoor samples contained only Aroclor 1242, while the outdoor samples contained a mixture of Aroclor 1242 and 1254.The amounts of PCBs measured were below the safety level for working atmosphere, as recommended by NIOSH in 1977. However, knowing that the samples were collected in an office where there was no known use of PCBs, the levels found were unexpectedly high.Further investigations should therefore be undertaken to clarify whether datascreen terminals might be sources of PCB-contamination.     

Cardiovascular and hematological parameters affected by feeding various polychlorinated biphenyls to the single comb white leghorn cockerel

The effect of dietary PCBs (50–200 ppm) on some cardiovascular and hematological parameters in the SCWL cockerel was investigated. Heart rate was significantly reduced by PCB 1242 and 1254 at 100 ppm and was not altered by PCB 1221 or 1260 at 150 ppm. A significant decrease in arterial blood pH was observed with PCB 1254 at 150 ppm. Mean blood pressure was unaffected by any treatment used. Hemoglobin concentration, HCT, and total erythrocyte count were found to be significantly decreased by PCBs 1242 and 1254 at 50 ppm. These same parameters were not affected by PCB 1221 or 1260 at any level used. It was concluded that the anemia observed was due solely to a decrease in total erythrocyte concentration. The possibility that these changes may be due to a decrease in erythropoiesis is discussed. Pericardial fluid volume was increased with PCBs 1242 and 1254; however, there was no correlation between the magnitude of the bradycardia and the amount of pericardial fluid.Michigan Agricultural Experiment Station Journal Article 6411.     

Biological uptake of polychlorinated biphenyls by Macoma balthica from sediment amended with activated carbon

This work characterizes the efficacy of activated carbon amendment in reducing polychlorinated biphenyl (PCB) bioavailability to clams (Macoma balthica) from field-contaminated sediment (Hunters Point Naval Shipyard, San Francisco Bay, CA, USA). Test methods were developed for the use of clams to investigate the effects of sediment amendment on biological uptake. Sediment was mixed with activated carbon for one month. Bioaccumulation tests (28 d) were employed to assess the relationships between carbon dose and carbon particle size on observed reductions in clam biological uptake of PCBs. Extraction and cleanup protocols were developed for the clam tissue. Efficacy of activated carbon treatment was found to increase with both increasing carbon dose and decreasing carbon particle size. Average reductions in bioaccumulation of 22, 64, and 84% relative to untreated Hunters Point sediment were observed for carbon amendments of 0.34, 1.7, and 3.4%, respectively. Average bioaccumulation reductions of 41, 73, and 89% were observed for amendments (dose = 1.7% dry wt) with carbon particles of 180 to 250, 75 to 180, and 25 to 75 microm, respectively, in diameter, indicating kinetic phenomena in these tests. Additionally, a biodynamic model quantifying clam PCB uptake from water and sediment as well as loss through elimination provided a good fit of experimental data. Model predictions suggest that the sediment ingestion route contributed 80 to 95% of the PCB burdens in the clams.     

Polychlorinated Biphenyl Congeners in River Sediments: Distribution and Source Identification Using Multivariate Factor Analysis

To assess the level of polychlorinated biphenyl (PCB) contamination and identify their sources, surface sediments were collected from selected locations along Nakdong River, Korea, and analyzed for 209 PCB congeners using high-resolution gas chromatography/high-resolution mass spectroscopy. PCB levels ranged from 0.124 to 79.2 ng/g dry weight (coplanar PCBs 0.295 to 5720 pg/g dry), which were similar to those of three other major rivers (Han, Geum, and Youngsan rivers) in Korea but slightly lower than those in neighboring countries. Regarding homologue composition, tetra-CBs were most abundant in most samples, but some samples with much higher PCBs concentrations had relatively lower proportions of tetra-CBs and higher proportions of penta- to hepta-CBs. To identify the sources of PCBs in sediment samples, principal component analysis/absolute principal component scores (PCA/APCS), positive matrix factorization (PMF), and multiple linear regression (MLR) were used with the congener composition of aroclors (1242, 1248, 1254, and 1260) and the flue gas of waste incinerators (data obtained from a previous article) as source profiles. Results showed that the three models showed similar source apportionments. Most sediment samples with lower PCB concentrations had higher proportions of incineration-derived materials, and some sediment samples with much higher PCB concentrations had higher proportions of aroclor 1260. This occurred because many industrial facilities, such as landfill leachate–treatment facilities, were gathered around sampling points with high PCB concentrations, and high-chlorinated PCBs are more stable in the elution process of landfill leachate than the incineration process. PCB concentrations estimated by APCS, PMF, and MLR were similar to the measured values with coefficients of determination ranging from 0.77 to 0.99.     

Half-life of polychlorinated biphenyls in occupationally exposed workers

In 1977 and 1985, serum polychlorinated biphenyl (PCB) concentrations were determined for 58 workers in a Bloomington, Indiana, factory that used polychlorinated biphenyls (PCBs) in capacitor manufacture until 1977. Less chlorinated PCBs were quantitated as Aroclor 1242, and more highly chlorinated PCBs were quantitated as Aroclor 1254. The median half-life was 2.6 y for Aroclor 1242 and 4.8 y for Aroclor 1254. However, the half-life varied inversely with the initial serum concentration. This pattern may be a result of continued low-level exposure, variation in the time of exposure, or enzyme induction by PCBs.     

Accumulation of polychlorinated organic contaminants from sediment by three benthic marine species

A laboratory experiment was conducted to measure the accumulation of selected polychlorinated compounds by marine benthos exposed to environmentally contaminated sediment. Sandworms (Nereis virens), clams (Macoma nasuta), and grass shrimp (Palaemonetes pugio) were exposed to sediment collected from the Passaic River, New Jersey. All three species accumulated 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3, 7,8-TODD), 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF) and polychlorinated biphenyls (PCBs) from the sediment. In addition, a recently identified sulfur containing analog of tetrachlorinated dibenzofurans, 2,4,6,8-tetrachlorodibenzothiophene (2,4,6,8-TCDT), accumulated in the three species.Accumulation factors (AFs) were calculated (([organism]/lipid) / ([sediment]/total organic carbon)) and used to compare results among species and compounds. These comparisons showed that AFs measured for clams reached steady-state levels rapidly (10 days); however, steady-state Al's values were not achieved until 70–120 days in sandworms. Grass shrimp were exposed to test sediments for only 28 days; therefore, steady-state concentrations could not be determined for this species.Although final contaminant concentrations were highest in the sandworms, AFs were generally higher for the clams and shrimp and lower for the sandworms. The AFs for 2,4,6,8-TCDT were significantly higher for shrimp than for sandworms and clams. PCB 153 showed higher AF values than those of the other compounds studied.Clams showed preferential accumulation of lower molecular weight PCB congeners which may be due to the very low lipid content in this species. Sandworms and especially shrimp appeared to metabolize congeners 52, 101, and 151 which all contain vicinal hydrogens in the meta and para regions of the molecule.     

Effects of polychlorinated biphenyls on thyroid hormones and liver type I monodeiodinase in the chick embryo.

Polychlorinated biphenyls (PCBs) are widespread environmental contaminants which can biomagnify to higher tropic level organisms including birds. Circulating thyroid hormones (TH) and growth are decreased by PCB exposure. The first set of studies investigated the effects of PCBs on an enzyme responsible for TH homeostasis, hepatic type I monodeiodinase (MDI) in chicken embryos. Fertile chicken eggs were injected with Aroclor 1242, Aroclor 1254, 2,2',6, 6'-tetrachlorobiphenyl (TCB), 3,3',4,4'-TCB, or 3,3',5,5'-TCB on Day 0 and studies were terminated on Incubation Day 21. Hepatic MDI activity was reduced in embryos treated with the Aroclor mixtures. No effects on MDI activities were observed after PCB isomer treatment. Liver weights from embryos treated with Aroclor 1242 were decreased. In the second study, chick embryos were exposed to these same PCBs in order to evaluate their effect on circulating THs and growth. Treatment with PCBs had no effect on body weight. Femur length were decreased with Arcolor 1242 treatment. A decrease in plasma concentration of thyroxine was observed after treatment with Aroclor 1242 and Aroclor 1254. Based on these findings, it is evident that PCBs alter the thyroid axis. Bird circulating TH levels, which are generally reported, may not be a good biomarker for low-dose exposure to PCBs. However, the reduction in MDI activity was more sensitive to PCB mixture exposure and may be a useful biomarker.     

The effects of polychlorinated biphenyls (Aroclors® 1016 and 1254) on mortality,reproduction, and regeneration inHydra oligactis

Budding and tentacle regeneration were observed inHydra oligactis following exposure to the commercial PCB mixtures Aroclor 1016 and 1254. The acute toxicity of these PCB s was also compared by determining their respective 72-hr LC50s. The animals were exposed to the PCBs as a component of an artificial pond water medium with PCB dilutions being made from a 49:1, reagent grade acetone:PCB solution. All exposures were continuous with the medium being replaced daily. Animals used in studying the effects of these chemicals on tentacle regeneration had their heads transected at the time of initial exposure to the PCBs. Observation were taken at 24, 48, 72, and 96-hr of incubation at 19 ±0.2°C.Aroclor 1016 was more toxic than the more widely occurring 1254, with 72-hr LC50s of 5 mg/L and 20 mg/L, respectively. The two chemicals suppressed bud initiation equally, however, Aroclor 1254 had a significantly greater inhibitory effect on bud detachment when equal concentrations of the two PCBs were compared. As was the case with mortality, Aroclor 1016 had four times the suppressive effect of Aroclor 1254 on tentacle regeneration, with 50% inhibition occurring at 1 mg/L and 4 mg/ L, respectively. The quantitatively different effects on the two PCBs on mortality and tentacle regeneration may have been due to structural differences between the two PCBs or the different aqueous solubility properties (1016 being more soluble) of these chemicals. The results on bud initiation and detachment indicated that this developmental process may have been affected by the PCB through a different mechanism than was mortality and tentacle regeneration.Registered trademark, Monsanto Co., St. Louis, MO     

Availability of polychlorinated biphenyls in field-contaminated sediment

Two chemical approaches, Tenax extraction and matrix solid phase microextraction (matrix-SPME), were evaluated as surrogates to estimate bioavailability of polychlorinated biphenyls (PCBs) from field-contaminated sediment. Aroclor 1254 was the primary contaminant found in sediment from Crab Orchard Lake in Marion, Illinois, USA, and a total of 18 PCB congeners were selected for study. Bioaccumulation was determined by exposing the freshwater oligochaete, Lumbriculus variegatus, to the sediment for 28 d. Differences in the rapidly desorbing fraction of PCBs and fraction desorbed within 6 h, defined by Tenax extraction, accounted for 39 and 31% of the differences among biota-sediment accumulation factor values, respectively. A better relationship (r2 = 0.95) was found between the oligochaete PCB body residues and the concentration of PCBs in the rapidly desorbing fraction of sediment. The degree of chlorination and planarity of the PCB congeners affected both desorption and bioaccumulation. The higher chlorine substituted and planar PCBs showed less chemical and biological availability, due to their stronger sorption to sediment, compared to the lower chlorinated and nonplanar PCBs. Accumulation of PCBs by L. variegatus correlated well (r2 = 0.88) with matrix-SPME fiber concentrations. The ratio of measured body residue to estimated body residue from the pore water concentration measured by matrix-SPME ranged from 0.4 to 1.3 with an average of 0.9. Overall, both Tenax and matrix-SPME approaches were useful surrogates of bioaccumulation for a field-contaminated sediment.     

Polychlorinated Biphenyls in the Atmosphere of an Urban City: Levels,Distribution, and Emissions

Polychlorinated biphenyl (PCB) concentrations, profiles, and possible sources were determined in the atmosphere of Guangzhou, the largest city in south China. ∑PCB concentrations ranged from 160 to 2720 pg/m³, which is comparable with values found by similar studies in North America, Europe, and Asia. The highest PCB concentrations were found in the old industrial district, suggesting it to be the principal emission source. The most important PCB homologue group was tetra-PCB, followed by tri- and penta-PCB. The PCBs’ homologue composition differs from that found in Chinese transformer oils: Chinese PCB products (no. 1 PCB and no. 2 PCB), Aroclor1242, and Aroclor1254. However, it is similar in composition to that found in sediments and soils subjected to arbitrary disposal of used electronic appliances in this region. Our results suggest that volatilization from PCB-contaminated soils in the old urban center may be the major source of PCBs in the atmosphere of Guangzhou. Additional studies will be required to characterize the geochemical cycles of PCBs from the contaminated environmental “hot spots” during the typical subtropical climate conditions in the study regions.     

Accumulation of trace elements,pesticides, and polychlorinated biphenyls in sediments and the clamCorbicula manilensis of the Apalachicola River,Florida

A survey of trace element and synthetic organic compound concentrations in bottom materials was conducted on the Apalachicola River in northwest Florida in 1979–80 as part of the Apalachicola River Quality Assessment. Substances analyzed included trace elements (predominantly heavy metals), organochlorine insecticides, organophosphorus insecticides, chlorinated phenoxy-acid herbicides, and poly chlorinated biphenyls (PCBs). Three kinds of materials were surveyed: finegrained sediments, whole-body tissue of the Asiatic clamCorbicula manilensis, and bottom-load organic detritus. No hazardous levels of any of the substances were found. Concentrations in the finegrained sediments and clams were generally at least ten times lower than maximum limits considered safe for biota of aquatic systems. A comparison of trace-substance data from the Apalachicola River with data from Lake Seminole (upstream) and Apalachicola Bay (downstream) showed lower concentrations in riverine clams. Sediment concentrations in all parts of the system were comparable. Most trace substances in the Apalachicola River enter the river from the upstream part of the basin (the Chattahoochee and Flint Rivers in Georgia and Alabama) and from nonpoint sources throughout the basin. There are no major point discharges along the Apalachicola. Trend analysis was limited by the scope of the study, but did not reveal any spatial or temporal trends in concentrations of any of the substances analyzed. Concentrations of organic compounds and most metals inCorbicula manilensis did not correlate with those in sediments.     

Comparability and precision of serum PCB measurements

The 95% prediction interval for single measurements of serum "Aroclor" reported by a reputable commercial analyst was found to be approximately +/- 42%. The geometric mean serum PCB levels in a population of capacitor workers who had formerly had direct exposure to the commercial PCBs--Aroclors 1016, 1242, and 1254-were found to be alternatively reportable as 1905 ppb minimum initial PCBs (as calculated from most persistent peaks present); 1093 ppb non-overlapping analytical "Aroclor" levels (as calculated by the conventional sum-of-the-peak-heights method); 303 ppb total PCBs actually present; or 19 ppb "human PCB" (as calculated by the NHMP procedure). The broad spread in reportable values was relatable to the PCB isomer distribution and clearance patterns in the occupationally exposed population.     

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.     

Stimulation of contraction of pregnant rat uterus in vitro by non-dechlorinated and microbially dechlorinated mixtures of polychlorinated biphenyls

A previous study of six polychlorinated biphenyl (PCB) congeners showed that PCBs with four or fewer chlorines and ortho substitution stimulate uterine contraction frequency in vitro, whereas congeners with a greater number of chlorines or non-ortho substitution are inactive in vitro. We tested the hypothesis that PCB mixtures stimulate uterine contractions in a manner inversely related to the degree of chlorination and the presence of chlorines in the ortho- position of the biphenyl constituents of the mixtures. Uterine strips from pregnant rats were suspended in standard muscle baths and analyzed for changes in isometric contractions in response to in vitro exposure to commercial PCB mixtures (Aroclors) and their dechlorinated products after microbial degradation. The PCB mixtures Aroclor 1242, 1248, and 1254 significantly stimulated uterine contraction frequency, and the least chlorinated mixture, Aroclor 1242, was the most potent stimulant. Microbes from Hudson River sediment dechlorinated Aroclor 1242 and Aroclor 1254 under reducing conditions to produce mixtures with an increased proportion of ortho-substituted congeners with one or two chlorine substitutions. The PCB mixtures that had undergone microbial reductive dechlorination stimulated uterine contraction frequency to a significantly greater extent than the parent mixtures. These results show that increased uterotonic activity was associated with decreased chlorination and increased ortho substitution of the biphenyl constituents of the mixtures.     

PCB-induced changes of a benthic community and expected ecosystem recovery following in situ sorbent amendment

The benthic community was analyzed to evaluate pollution-induced changes for the polychlorinated biphenyl (PCB)-contaminated site at Hunters Point (HP) relative to 30 reference sites in San Francisco Bay, California, USA. An analysis based on functional traits of feeding, reproduction, and position in the sediment shows that HP is depauperate in deposit feeders, subsurface carnivores, and species with no protective barrier. Sediment chemistry analysis shows that PCBs are the major risk drivers at HP (1,570 ppb) and that the reference sites contain very low levels of PCB contamination (9 ppb). Different feeding traits support the existence of direct pathways of exposure, which can be mechanistically linked to PCB bioaccumulation by biodynamic modeling. The model shows that the deposit feeder Neanthes arenaceodentata accumulates approximately 20 times more PCBs in its lipids than the facultative deposit feeder Macoma balthica and up to 130 times more than the filter feeder Mytilus edulis. The comparison of different exposure scenarios suggests that PCB tissue concentrations at HP are two orders of magnitude higher than at the reference sites. At full scale, in situ sorbent amendment with activated carbon may reduce PCB bioaccumulation at HP by up to 85 to 90% under favorable field and treatment conditions. The modeling framework further demonstrates that such expected remedial success corresponds to exposure conditions suggested as the cleanup goal for HP. However, concentrations remain slightly higher than at the reference sites. The present study demonstrates how the remedial success of a sorbent amendment, which lowers the PCB availability, can be compared to reference conditions and traditional cleanup goals, which are commonly based on bulk sediment concentrations.     

Monitoring of Organochlorine Pesticide Residue Levels in Adipose Tissue of Veracruz,Mexico Inhabitants

The concentrations of 20 Polychlorinated biphenyls (PCBs) were determined in 12 superficial sediments collected from The Ghar El Melh lagoon. Sediment samples were extracted by Soxhlet and analyzed by Gas chromatography with electron capture detector. The concentrations of PCBs, as sum of the 20 congeners, ranged from not detected to 3.987 ng/g on a dry weight basis, with a predominance of highly chlorinated (penta- and hepta-chlorobiphenyls) congeners. No significant correlation was found between the total PCB concentrations and organic carbon content suggesting that sediment organic carbon content did not play an important role in controlling the PCBs levels in the sediments. PCB levels in sediments were compared with Sediments Quality Guidelines (ERM–ERL indexes) for evaluation probable toxic effects on marine organism. The PCBs concentrations were lower than ERM and ERL values for all the collected samples.     

Dependency of polychlorinated biphenyl and polycyclic aromatic hydrocarbon bioaccumulation in Mya arenaria on both water column and sediment bed chemical activities

The bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) by the filter-feeding soft-shell clam Mya arenaria was evaluated at three sites near Boston (MA, USA) by assessing the chemical activities of those hydrophobic organic compounds (HOCs) in the sediment bed, water column, and organisms. Polyethylene samplers were deployed to measure the activities of HOCs in the water column. Sediment activities were assessed by normalizing concentrations with sediment-water sorption coefficient values, including adsorption to black carbon in addition to absorption by organic carbon. Likewise, both lipids and proteins were considered in biota-water partition coefficients used to estimate chemical activities in the animals. Chemical activities of PAHs in M. arenaria were substantially less than those of the corresponding bed sediments in which they lived. In contrast, chemical activities of PCBs in M. arenaria often were greater than or equal to activities in the corresponding bed sediments. Activities of PAHs, such those of pyrene, in the water column were undersaturated relative to the sediment. However, some PCBs, such as congener 52, had higher activities in the water column than in the sediment. Tissue activities of pyrene generally were in between the sediment and water column activities, whereas activity of PCB congener 52 was nearest to water column activities. These results suggest that attempts to estimate bioaccumulation by benthic organisms should include interactions with both the bed sediment and the water column.     

Studies of transformer repair workers exposed to PCBs: I. Study design, PCB concentrations, questionnaire, and clinical examination results

A cross-sectional study compared 55 transformer repairmen, 38 currently, and 17 previously exposed to polychlorinated biphenyls (PCBs) with 56 non-exposed subjects. PCBs exposures occurred from air and contaminated surfaces, predominantly from Aroclor 1260 with some exposure to Aroclor 1242. Each worker underwent: a questionnaire; standardized medical examination; delayed hypersensitivity testing; and determination of serum and adipose tissue lipid total PCB concentrations. Adipose and serum [PCBs] were significantly higher in the currently exposed, but previously exposed workers did not differ significantly from comparison subjects. No subjects had a classical syndrome of PCB poisoning. A number of neurobehavioral and irritant symptoms were significantly more prevalent in the exposed group, but were probably not related to PCBs. Comedones were more frequent in the exposed group, but no evidence of classical chloracne was noted. Cutaneous delayed hypersensitivity responses to mumps and to trichophyton antigens did not differ between the groups. The association of PCBs with job functions were explored.     

Polychlorinated biphenyl congeners in sediments,plankton, molluscs,crustaceans, and eel in a freshwater lake: Implications of using reference chemicals and indicator organisms in bioaccumulation studies

The concentrations of six polychlorobiphenyl (PCB) congeners in sediments and four classes of biotic species of the aquatic food chain were investigated in a freshwater lake near Amsterdam. Despite the low concentrations of the contaminants in the sediment, significant amounts of PCBs were found in plankton, macro-invertebrates and fish. The composition of the PCB mixtures found in the various organisms cannot be explained in terms of simple partitioning of the PCB congeners between sediment, water, and organisms. In addition to bioconcentration, it is likely that biomagnification via consumption of contaminated food also contributed significantly to the total PCB concentrations. This is most pronounced for the higher trophic food-chain organisms. Studying bioaccumulation processes by monitoring just one type of organism is probably not very suitable, due to the pronounced differences in accumulation patterns demonstrated for the different organisms. In addition, significant differences were found in the accumulation of the six PCBs in the various biotic samples. This indicates that the fate of mixtures of PCBs is determined by the fate of the individual congeners and therefore cannot be monitored in terms of total PCBs concentrations.