PCB Levels Research Articles

Congener‐specific model for polychlorinated biphenyl effects on otter (Lutra lutra) and associated sediment quality criteria

A model for risk assessment was built for simultaneous, congener-specific PCB bioaccumulation from sediment to fish to otters (Lutra lutra). Toxic equivalence factors (TEFs) were used to sum individual congeners in otters to a toxic equivalent concentration (TEQ) relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin. Microbial dechlorination and burial in sediments and bioaccumulation are modeled to predict time trends of PCB concentrations in otters. Effects of accumulated PCBs on otters were assessed for vitamin A metabolism and reproduction, taking model uncertainty into account. Three locations in The Netherlands were modeled with PCB levels in sediment of 1 to 171 pg TEQ/g organic carbon (OC). Almost 100% reduction in litter size was predicted for the most polluted area in 1996. Due to large associated uncertainty, a period of 25 to 80 years may be needed for recovery of otter vitamin A levels and litter size at this site. Calculated median sediment quality criteria (SQC) range between 1 and 12 pg TEQ/g OC, depending on the chosen effect criterion. Uncertainty in calculated effects and SQCs is substantial and is mainly caused by uncertainty in PCB congener 126 accumulation.

Serum levels of TCDD and dioxin-like chemicals in Rhesus monkeys chronically exposed to dioxin: correlation of increased serum PCB levels with endometriosis.

Humans and animals are exposed daily to a complex mixture of polyhalogenated aromatic hydrocarbons (PHAHs). Previous work has shown that exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is associated with a dose-dependent increase in the incidence and severity of endometriosis in the rhesus monkey. Dioxin-like chemicals can also exert effects in combination with TCDD via the aryl hydrocarbon receptor. This study demonstrates that the serum levels of TCDD and specific dioxin-like PHAH congeners were increased in TCDD-treated animals with endometriosis 13 years after the TCDD exposure. Nine TCDD-exposed and 6 unexposed female rhesus monkeys were evaluated for serum content of relevant compounds and for endometriosis by surgical laparoscopy. Additional studies were done on 4 animals that died 7 to 11 years after exposure to TCDD and 4 lead-treated animals with no history of PHAH treatment. For TCDD-exposed and unexposed animals, TCDD exposure correlated with an increased serum TCDD concentration. Furthermore, TCDD exposure and an elevated serum TCDD concentration were associated with increased serum levels of triglycerides, 1,2,3,6,7,8-hexachlorodibenzofuran, 3,3',4,4'-tetrachlorobiphenyl (TCB) and 3,3'4,4',5-pentachlorobiphenyl (PnCB). Importantly, the animals with elevated serum levels of 3,3',4,4'-TCB, 3,3',4,4',5-PnCB and an increased total serum TEQ had a high prevalence of endometriosis, and the severity of disease correlated with the serum concentration of 3,3,',4,4'-TCB. Increased serum concentrations of coplanar PCBs were also present in lead-treated animals. Implications of these findings for human health and the prevalence of endometriosis in humans will be discussed.

Determination of polychlorinated biphenyl compounds in electrical insulating oils by enzyme immunoassay

The development and performance of a competitive indirect immunoassay for the quantitation of polychlorinated biphenyl compounds (PCBs) in insulating oils is described. Reagent preparation and the assay characterisation, optimisation and validation steps are described. The dynamic range of the assay for Aroclors 1254 and 1260 in methanol was 30–1000 ng ml −1 with 50% signal inhibition values of 217 and 212 ng ml −1, respectively. Impending legislation in the UK is likely to decree that oils containing >50 μg ml −1 PCBs be considered contaminated. Assay sensitivity increased with the degree of PCB chlorination. The assay of structurally related compounds of environmental concern yielded cross-reactivity values of <0.6%. The immunoassay proved reliable for the analysis of diluted transformer oils containing >35 μg ml −1 PCB (neat) but over-estimated PCB levels in diluted oils containing <10 μg ml −1 of neat analyte. The oils required pre-treatment using either solid-phase extraction or washing with KOH–ethanol/sulphuric acid to remove matrix interferents. The analytical performance of the assay was compared against a commercially available semi-quantitative immunoassay kit for PCBs in soil and water.

A Model of PCB Fate in the Upper Hudson River

A mechanistic model of PCB fate, transport, and bioac cumulation in the Upper Hudson River was developed to provide a quantitative tool to assess the effectiveness of natural recovery and active remediation in reducing PCB levels in water, sediment, and biota. The fate and transport modeling, which is the subject of this paper, builds on previous approaches by using a mechanistic sediment-transport model that describes erosion and deposition with sufficient accuracy to remove the requirement to adjust sediment transport as part of the contaminant calibration process. An additional significant aspect of the model is the calibration and validation for both the short time scale of erosion events and the decade-long time scale associated with trends in sediment contamination.The model demonstrates differences between PCB fate in cohesive and noncohesive sediments that are important to efforts to reduce perceived human health and ecological risks. Burial due to the deposition of solids with lower PCB concentra...

Organochlorine and heavy metal residues in the water/sediment system of the Southeast Regional Park in Madrid, Spain

A study into levels of contamination by organochlorine compounds (insecticides and PCBs) and heavy metals (Cd and Pb) in the water/sediment system of the Southeast Regional Park (SERP) in Madrid, Spain, has been carried out. Residue levels of xenobiotics were determined in surface and underground waters and sediments from selected sites throughout the protected area. The results showed these contaminants to be widespread throughout the studied area. p,p′-DDT concentration levels were consistently higher than its metabolite p, p′-DDE, indicating a recent use of this organochlorine insecticide in the area. PCB levels exceeded, in the majority of the cases, the levels taken as the maximum (100 ng/μl) for highly polluted waters. Cd and Pb levels found in water samples were under the detection limits of the methodology used. Pb levels found in sediment samples were higher than Cd.

Exposure of populations to dioxins and related compounds

The present situation with respect to the exposure of the general human population to PCDDs, PCDFs and (dioxin-like) PCBs and specific issues that should be taken into consideration for a risk assessment of these exposures have been summarized. The information is based on studies performed in The Netherlands and Germany in the last 10 years. Additional data have been collected through a literature search and through many contacts with researchers and national authorities. The most important route for human exposure to PCDDs, PCDFs and (dioxin-like) PCBs is food consumption contributing over 90% of total exposure, with products of animal origin and fish making the greatest contribution to this exposure. The dietary intake of PCDDs and PCDFs by the general population of industrialized countries is on average 1–3 picograms of (i)-TEQ per kilogram body weight per day. If the contribution of dioxin-like PCBs are also considered, the daily TEQ intake can be a factor of two to three higher. Special consumption habits and consumption of highly contaminated foodstuffs may lead to lower and higher TEQ intakes. In general, TEQ intake increases during childhood and stabilizes in adults of about 20 years of age. However, when normalized by body weight exposure is found to decrease with childhood age due to increasing body weight. Exposure has been shown to have fallen over time in all countries where data are available. Countries that started to implement measures to reduce dioxin emissions in the late 1980s, such as The Netherlands, United Kingdom and Germany, clearly show decreasing PCDD/PCDF and PCB levels in food and consequently a significantly lower dietary intake of these compounds by almost a factor of 2 within the past 7 years.

Chemical contamination of bottom sediments of Pechenga Bay, Barents Sea

The results of a 1977 survey of contamination levels in bottom sediments from the Pechenega Bay, Barents Sea, are presented. Aliphatic and aromatic hydrocarbons, chlorinated hydrocarbons (11 PCB congeners, DDT with metabolites, HCB, alpha‐HCH, lindane), and trace elements were analyzed in samples from five sites. Levels of trace elements and of polycyclic aromatic hydrocarbons (PAH) were found to be low. High levels of PCB and some pesticides found in the bottom sediments indicate anthropogenic contamination sources. Translated by Edward Torrey, Alexandria, VA from: Izvestiya Rossiyskoy Akademii Nauk, seriya geograficheskaya 2000, No. 1, pp. 79–87.

Geographical differences and time trends of persistent organic pollutants in the Arctic

Geographical and temporal trends of total PCBs (Σ PCBs) and hexachlorocyclohexanes (Σ HCHs) have been examined in polar bear ( Ursus maritimus) adipose tissue and ringed seal ( Phoca hispida) blubber along a transect from Alaska to Svalbard and northern Norway/western Russia. PCB concentrations in polar bear show a strong west to east trend with higher levels in east Greenland, Svalbard. In ringed seal, highest PCB levels were found at two sites near the Russian coast. Σ HCHs levels in ringed seals and polar bear show the reverse trend coinciding with much higher levels of Σ HCHs in seawater in the North American Arctic. Some of these geographical differences may reflect dietary differences especially in the case of PCBs. Levels of Σ PCBs in polar bears in the eastern Canadian Arctic appear to have increased from the 1970s to the 1980s but are now on the decline. Σ PCBs and Σ HCHs levels showed no significant change from the mid-1980s to 1990s in ringed seal blubber from three locations in the eastern Canadian Arctic.

Organochlorines and possible biochemical effects in glaucous gulls (Larus hyperboreus) from Bjørnøya, the Barents Sea.

To study possible biochemical effects of organochlorine contaminants (OCs) in glaucous gulls (Larus hyperboreus), 40 adult individuals were collected from colonies on Bjornoya in the Barents Sea. OCs (four pesticides and nine PCB congeners), microsomal 7-ethoxyresorufin O-deethylase (EROD) activity, microsomal testosterone hydroxylation, highly carboxylated porphyrins (HCPs), retinol, and retinyl palmitate were quantified in liver samples. The hepatic vitamin A stores in glaucous gulls were larger than in herring gulls (Larus argentatus) from other studies conducted in contaminated locations in North America. No significant relationships were found between liver retinoid concentrations and OC levels. The hepatic EROD activity was low compared to other studies on fish-eating birds and only marginally associated with PCB levels. Microsomal testosterone hydroxylase activity was only observed at the 6beta-position and could not be related to OC levels. The low P450-associated enzyme activities in the glaucous gull suggests that they have a low capacity for metabolizing OCs, which may contribute to the high accumulation of OCs in this species. HCPs were only elevated (138 pmol g(-1)) in the sample with highest OC levels, whereas the remaining samples contained low levels of HCPs (<30 pmol g(-1)). The weak association between EROD activity and PCB levels and the low level of HCPs suggest that these biochemical parameters were unaffected by OCs in most of the sampled gulls. Thus, the glaucous gull seems not to be particularly sensitive toward Ah-receptor mediated effects.

Declining PCB Concentrations in the U.K. Atmosphere: Evidence and Possible Causes

PCB air concentrations have been measured at a meteorological site in northwest England since 1992. Examination of this data set, comprising over 200 data points, suggests that PCB levels are decreasing with average congener specific half-lives ranging from approximately 2 to 6 yr. With the exception of congener 52, which shows the steepest decline, the slopes of other ICES congeners included in this study (i.e., 28, 101, 118, 153, and 138) were not found to be significantly different from each other. A U.K. mass balance model has been used to examine which factors are likely to be controlling present and future air concentrations. This allowed a range of fate scenarios to be examined and the controlling fate processes to be scrutinized. Estimates of fluxes using contemporary soil and air concentrations suggest that the observed long-term decrease of PCB levels in U.K. air is likely to be influenced by several factors, including existing primary emissions and recycling, volatilization from soil, advective losses from the U.K. atmosphere, reaction in the atmosphere, and soil fate processes such as microbial degradation.

PCB Levels in Laminated Coastal Sediments of the Baltic Sea along Gradients of Eutrophication Revealed by Stable Isotopes (δ15N, δ13C)

Abstract A systematic investigation of PCB in coastal sediments of the Baltic Sea was initiated in 1996 by retrieving dated subsurface layers (1992–1994) from 88 sites in 19 sheltered archipelago areas, where laminated sediments were found to be common. PCBs7 (HELCOM's standard sum of 7 congeners, ≈1/6 of total PCB) was quantified, as well as the abundance and isotopic composition of nutrients (N, C), in order to trace effects of eutrophication and potential influences on the turnover of PCB. In most of the areas, the median of PCBs7/C was within 70 to 120 ng g−1 C. This is similar to recent values in regional offshore sediments, and thus consistent with a rapid exchange between coastal and open waters. Elevated PCBs7 levels up to around 1000 ng g−1 C were found within 50 km from Stockholm. Here, but not in other areas, PCBs7/C increased linearly with the degree of eutrophication. This was evident from the isotopic composition of sediment N and C, reflecting local eutrophication as well as its link to fre...

Seasonal Variations of DDT Compounds and PCB in a Eutrophic and an Oligotrophic Lake in Relation to Algal Biomass

Abstract Interactions between eutrophication and organic pollutants (PCB, DDTs and γ-HCH) were investigated during 1996-1997 in two lakes, one eutrophic (Lake E) and one oligotrophic (Lake O) but with otherwise similar morphometry and water chemistry. Soil samples from the watersheds indicated similar atmospheric exposure of the lakes. No biomass dilution was observed in Lake E compared to Lake O. Lake E had higher levels of PCB based on organic carbon and lipid mass in sedimenting matter (1.5×), surface sediment (1.4×) and perch (Perca fluviatilis) (2.4×), and also higher settling fluxes of particulate matter and PCB measured in sediment traps and in surface sediment. Phytoplankton was responsible for most of the PCB transport to the sediment in Lake E. Higher DDD/DDE ratios seemed to correlate to a high load of p,p′-DDT more than to that of anaerobic conditions. A high DDD/DDE ratio was recorded in the deep sediment core from Lake O together with high levels of sDDT and was also highest in the sediment ...

A Source of PCB Contamination in Modified High-Volume Air Samplers

Modified Anderson High Volume (Hi-Vol) air samplers are widely used for the collection of semi-volatile organic compounds (such as PCBs) from air. The foam gasket near the main air flow path in these samplers can become contaminated with PCBs if the sampler or the gasket is stored at a location with high indoor air PCB levels. Once the gasket is contaminated, it releases PCBs back into the air stream during sampling, and as a result, incorrectly high air PCB concentrations are measured. This paper presents data demonstrating this contamination problem using measurements from two Integrated Atmospheric Deposition Network sites: one at Sleeping Bear Dunes on Lake Michigan and the other at Point Petre on Lake Ontario. The authors recommend that these gaskets be replaced by Teflon tape and that the storage history of each sampler be carefully tracked.

RAPID MICROBIAL GROWTH ON POLYCHLORINATED BIPHENYL AND ITS FATE IN CELLS

Abstract Nine cultures were examined for growth at 37C in media with different levels of PCB and selected one culture to treat an industrial liquid waste containing high levels of PCB 1248. All the nine cultures grew well in the presence of 100 to 500 μg PCB 1254 mL−1 glucose basal salt broth (GBSB) as well as in tryptic soy broth (TSP) with no significant changes in generation time. The cultures grew well in basal salt agar containing PCB as sole source of carbon. Pseudomonas aeruginosa and Serratia liquefaciens strains survived for 75 to 120 min in the presence of 300 to 2000 μg PCB 1254 mL−1 sodium‐phosphate buffer (SPB) pH 7.0. The P. aeruginosa cells removed both PCB 1254 and 14C‐PCB from SPB and GBSB within 48 h and the percent uptakes were 26 and 39.7%, respectively. The results of the fate and distribution of PCB 1254, including 14C‐PCB, in cells of P. aeruginosa, S. liquefaciens, and two Bacillus strains grown in PCB‐media showed that more than 50% of the 14C‐PCB were in the alcohol and in alcohol‐ether soluble fractions (mostly lipids). This was also confirmed after rupturing the P. aeruginosa cells using French pressure and/or lysozyme and fractionation. Both the intrinsic flora and P. aeruginosa strain were used in a bioreactor system for the treatments of 27 and 33 gallons industrial liquid waste containing 150 and/or 800 mg PCB 12481 1−1, respectively, and complete oxidation was achieved, within approximately 150 days and the biological half‐life of the PCB was 30 and 15 days, respectively.

Patterns and Levels of Organochlorines (DDTs, PCBs, non-ortho PCBs and PCDD/Fs) in Male Harbour Porpoises (Phocoena phocoena) from the Baltic Sea, the Kattegat-Skagerrak Seas and the West Coast of Norway

Patterns and levels of chlorinated aromatic contaminants (DDTs, PCBs, non-ortho PCBs and PCDD/Fs) in blubber tissue were compared among six sample groups of male harbour porpoises (Phocoena phocoena) from the Baltic Sea, the Kattegat-Skagerrak Seas and the west coast of Norway. A principal component and classification analysis showed that mature harbour porpoises from the Baltic had significantly different contaminant patterns than animals from the Kattegat-Skagerrak and Norway. ANOVAs showed that mature porpoises from the Baltic had higher levels of ΣPCB and several individual PCBs and PCDD/Fs than the Kattegat-Skagerrak and the Norwegian samples and higher ΣDDT than the Norwegian. A comparison between immature porpoises showed that Baltic animals had higher levels of ΣPCDD/F than the corresponding sample from the Kattegat-Skagerrak. The levels of ΣDDT, ΣPCB and Σnon-ortho PCB were significantly higher in animals collected during 1978–81 compared to animals collected in 1988–90 indicating a temporal decline of these organochlorines in the Kattegat-Skagerrak Seas. The contaminant levels recorded in the Baltic Sea are a serious cause for concern and could have management implications for the already threatened harbour porpoises in this area.

The relation between levels of selected PCB congeners in human serum and follicular fluid

Individual congener and total PCB concentrations were determined in serum and follicular fluid obtained from women undergoing assisted reproductive technologies (in-vitro fertilization and embryo replacement). Although the mean individual PCB levels revealed varying degrees of contamination, the results fall in the same range as that observed by other investigators. Except for PCB 118, correlations between levels in serum and follicular fluid were strong, and statistically significant at p < 0.05. Moreover PCB 153, a major and very stable PCB congener has been shown to correlate to the total amount of PCBs ( r = 0.994, and r = 0.987, for serum and follicular fluid, respectively). The same accumulation patterns of PCBs for serum and follicular fluid have been observed.

Improved Procedure for Single DB-XLB Column GC-MS-SIM Quantitation of PCB Congener Distributions and Characterization of Two Different Preparations Sold as “Aroclor 1254”

Complete PCB congener distributions in a panel of Aroclor mixtures were previously obtained by combining data from several HRGC systems. In that study quantitation of minor components may have been unreliable due to single level calibration against high levels of individual congener standards. Two lots of Aroclor 1254 had markedly different congener distributions. In this study, the design and performance of a congener-specific PCB analysis method employing GC-MS-SIM detection of congeners separated on a DB-XLB capillary column are discussed. Quantitation is carried out against a 6-level inclusive standard curve of a mixture of 144 congeners found in Aroclors. A separate procedure to measure trace levels of PCB 126 in Aroclors using the same system, combined with levels initially acquired for other congeners, facilitates estimation of TEQ values (Toxic Equivalencies of the PCB mixtures to 2,3,7,8-TCDD). PCB congener profiles of 15 Aroclor 1254 mixtures are presented. These profiles show that the less common, high TEQ variety of Aroclor 1254 was manufactured by an atypical, two-stage chlorination process that was apparently used during the final 1% of Aroclor 1254 production (ca. 1974–1976).

Improved Procedure for Single DB-XLB Column GC-MS-SIM Quantitation of PCB Congener Distributions and Characterization of Two Different Preparations Sold as “Aroclor 1254”

Complete PCB congener distributions in a panel of Aroclor mixtures were previously obtained by combining data from several HRGC systems. In that study quantitation of minor components may have been unreliable due to single level calibration against high levels of individual congener standards. Two lots of Aroclor 1254 had markedly different congener distributions. In this study, the design and performance of a congener-specific PCB analysis method employing GC-MS-SIM detection of congeners separated on a DB-XLB capillary column are discussed. Quantitation is carried out against a 6-level inclusive standard curve of a mixture of 144 congeners found in Aroclors. A separate procedure to measure trace levels of PCB 126 in Aroclors using the same system, combined with levels initially acquired for other congeners, facilitates estimation of TEQ values (Toxic Equivalencies of the PCB mixtures to 2,3,7,8-TCDD). PCB congener profiles of 15 Aroclor 1254 mixtures are presented. These profiles show that the less common, high TEQ variety of Aroclor 1254 was manufactured by an atypical, two-stage chlorination process that was apparently used during the final 1% of Aroclor 1254 production (ca. 1974–1976).

Levels of Organochlorines (DDT, PCBs, Toxaphene, Chlordane, Dieldrin, and HCHs) in Blubber of South African Fur Seals ( Arctocephalus pusillus pusillus) from Cape Cross/Namibia

Organochlorines (DDT, toxaphene, PCBs, chlordane, HCHs, dieldrin) were quantified in the blubber of eleven fur seals of the species Arctocephalus pusillus pusillus. The sample clean-up included microwave-assisted extraction (MAE), gel-permeation chromatography (GPC), adsorption chromatography on silica gel and quantitation with GC/ECD. Compounds of technical toxaphene (CTTs) were determined after separation from the PCBs. Highest levels arose for p, p′-DDE (7–1000 μg/kg). A so far unknown compound labelled Q1 caused the second most abundant peak in the samples. Q1 was identified as a heptachloro compound by GC/MS in the electron capture negative ionisation and electron impact ionisation mode. Levels of Q1 were estimated relative to the ECD response factor of trans-nonachlor. These estimated Q1 levels ranged from 27 to 351 μg/kg being in the range or higher than the levels of PCBs (6–697 μg/kg), toxaphene (10–97 μg/kg), chlordane (3–159 μg/kg), and dieldrin (4–36 μg/kg). One sample which showed significantly higher DDT and PCB levels (but not toxaphene, dieldrin, Q1, and chlordane) than the others is most likely migrated from an area higher polluted with DDT and PCBs. Another one showed very low levels which were not explained. Except these samples, the levels determined in the blubber were among the lower levels reported for this kind of tissue. The data also confirmed that the organochlorine levels in Africa are varying from region to region, and that there is still a need for further research.

Evidence of Excess Cancer Mortality in a Cohort of Workers Exposed to Polychlorinated Biphenyls

Evidence of Excess Cancer Mortality in a Cohort of Workers Exposed to Polychlorinated Biphenyls