Total PCB Concentrations Research Articles

PCDD/F and PCB concentrations in Arctic ringed seals ( Phoca hispida) have not changed between 1981 and 2000

Concentrations of polychlorinated dibenzo- p-dioxins (PCDD) and dibenzofurans (PCDF) and of non- ortho-, mono- ortho- and di- ortho-substituted polychlorinated biphenyls (NO-CB, MO-CB and DO-CB) were measured in blubber of ringed seals sampled at Holman, NWT, in 1981, 1991, 1996 and 2000. Total PCDD and PCDF concentrations were usually below approx. 10 and 5 pg/g wet wt., respectively, and did not change significantly between 1981 and 2000, although there were sporadic temporal differences in some congeners. Total NO-CB, MO-CB and DO-CB concentrations were below approx. 1 ng/g, 250 ng/g and 1 μg/g wet wt. respectively; none of the total PCB concentrations changed significantly over the sampling period. Neither PCDD nor PCDF concentrations differed between males and females, nor did they increase with age in male samples. MO-CB and DO-CB concentrations increased with age in males, but not in females, and concentrations of total MO-CB and DO-CB were usually lower in females than in males. Changes in the distribution of PCB congeners between the 1980s and the 1990s are consistent with atmospheric transport processes becoming increasingly important in the introduction of PCBs to the Arctic in recent years.

An Integrated Case Study for Evaluating the Impacts of an Oil Refinery Effluent on Aquatic Biota in the Delaware River: Bivalve Bioavailability Studies

ABSTRACT The objectives of this study were to (1) determine the bioavailability of polycyclic aromatic hydrocarbons (PAHs) and other non-polar organics in resident brackish water clams (Rangia cuneata) at selected sites near an oil refinery; (2) determine if the tissue burdens were causing adverse effects to the clams, and (3) evaluate potential seasonal variations from reproduction in clams taken from the same beds in the spring and fall. Clams were evaluated from three beds located in the refinery discharge plume (near-field stations), three beds located up river outside of the Refinery effluent plume (north far-field), and three beds down river (south far-field) of the Refinery plume. Total PAH concentrations in the tissues of the near-field clams were significantly higher than in the clams located at the far-field stations in both the spring and fall. Total PAH concentrations of the near-field clams were significantly higher in the spring than the fall. No difference was found in total PAHs in the spring or fall in the far-field clams. Total pesticide and total PCB concentrations were significantly higher in the spring than the fall at all stations. The highest concentrations of both pesticides and PCBs were found at the north far-field stations. A tissue residue concentration analysis and three theoretical approaches for estimating detrimental effects to clams in both the near- and far-field suggested that no adverse effects should occur from total PAHs, total pesticides, or total PCBs. Some uncertainty, however, was associated with the theoretical approaches. An estimate of clam density in each clam bed showed that Rangia were growing and reproducing at all stations.

한국과 캐나다산 치즈중 PCBs의 농도 특성

All 209 PCB congeners were analyzed in cheese produced in Korea and Canada. 5 Korean and 10 Canadian cheeses were purchased in supermarket in their native countries. 93 PCB congeners were found in Korean cheese; 83 congeners were detected in Canadian cheese. Total PCB concentrations were 299.81 and 200.96 pg/g w.w. in Korean and Canadian cheeses respectively; PCB concentration was 1.5 times higher in Korean than Canadian cheese. Korean TEQ concentration (0.0067 pg-TEQ/g w.w.) in cheese was similar to in Canadian cheese (0.0064 pg-TEQ/g w.w.). These PCB concentrations range was low level compared with that of other cheeses globally. The correlation coefficient of regression was high (0.752) between each PCB congener concentration in both Korean and Canadian cheese.

Vertical fluxes and accumulation of PCBs in coastal sediments of the Río de la Plata estuary, Argentina

Settling particles and underlying sediments collected at 1, 2.5 and 4 km along offshore transects in the urbanized sector of the Río de la Plata were analyzed to evaluate the sources and accumulation of PCBs. Total PCB concentrations range from <0.1 to 100 ng g −1 and include variability associated to North–South and offshore gradients reflecting the impact of coastal discharges. Highest concentrations were recorded in the industrialized Central area close to Buenos Aires (61 ± 37 ng g −1 at 1 km) relative to cleaner northern stations (3.6 ± 2.2 ng g −1) and southward sites (37 ± 2.8 ng g −1), affected by transport of particulate PCBs by coastal currents. Sediment traps deployed in the Central area revealed large depositional fluxes of total matter (361 ± 124 g m −2 day −1) and PCBs (26 ± 19 μg m −2 day −1) and high sedimentation rates (5.0 ± 1.7 cm yr −1). Uniform PCB concentrations (66–89 ng g −1) down to 20 cm in sediment cores suggest continued PCB discharges during the last 4 years. PCB composition was dominated by hexa (43 ± 6.4%), hepta (23 ± 5.1%) and pentachlorobiphenyls (21 ± 5.5%) with lower proportions tri–tetra (7.4 ± 5.4%) and higher chlorinated congeners (5.1 ± 3.3%). A consistent weathering pattern with loss of 3–5 chlorobiphenyls and enrichment in higher chlorinated PCBs corresponding to a shift from a 1:1 to a 1:3 1254:1260 Aroclor mixture, was observed offshore. A principal component analysis performed with the relative contribution of PCB congener classes confirmed the offshore weathering pattern indicating that transformer oils containing Aroclor 1254–1260 are the most probable sources. Sediment inventories, sediment trap fluxes and Fugacity II calculations indicate an accumulation ∼500–800 kg PCB in superficial sediments of this coastal environment.

The sequestration of PCBs in Lake Hartwell sediment with activated carbon

Recent laboratory studies with a marine sediment from a tidal mudflat in San Francisco Bay demonstrated that a low dose of activated carbon enhances the sequestration of PCBs and PAHs under well-mixed conditions. Here we compare activated carbon treatment for a freshwater sediment from a rural site, using PCB-contaminated sediment from Lake Hartwell, SC. An activated carbon dose of 2% of the dry sediment mass lowered total aqueous PCB concentrations by more than 95% after 1 month of treatment and more than 98% after 6 months. Aqueous PCB concentrations remained below detection limits following 18 months of sediment–carbon contact in slowly mixed systems. Uptake of PCBs into semipermeable membrane devices was reduced by 78%, 91% and 97% over 1, 6 and 18 months, respectively. These tests show that PCB sequestration with activated carbon improves with contact time and is not diminished by prolonged mixing with sediment. Desorption studies confirmed the sequestration, in which 74% of the total PCB mass could be desorbed from untreated Lake Hartwell sediment within 30 days as compared to only 7% after activated carbon treatment for 6 months. We compare these observations with marine sediment from San Francisco Bay and propose a conceptual model to rationalize how sediment properties relate to the reduction in aqueous PCB concentrations during activated carbon treatment.

Association between lymphocyte proliferation and polychlorinated biphenyls in free‐ranging harbor seal (Phoca vitulina) pups from British Columbia, Canada

Recent pinniped die-offs have led to the speculation that persistent organic pollutants (POPs) are immunomodulatory, making individuals more susceptible to viral infections. Eighteen healthy harbor seal (Phoca vitulina) pups (aged 3-4 weeks) were live-captured from southern British Columbia, Canada, and maintained temporarily in captivity for an immunotoxicological assessment. The relationships between mitogen-induced peripheral blood lymphocyte proliferation and blubber concentrations of three major immunotoxic POP classes (the polychlorinated biphenyls [PCBs], polychlorinated dibenzo-p-dioxins [PCDDs], and the polychlorinated dibenzofurans [PCDFs]) were evaluated. A significant body weight-independent positive correlation was observed between both T-cell mitogen (phytohemagglutinin [PHA])- and B-cell mitogen (lipopolysaccharide [LPS])-induced lymphocyte proliferation and the blubber concentrations of total PCB. Best subset regression analysis revealed that total PCBs, and not total PCDD or total PCDF, explained 24 and 29% of the changes in both T-cell mitogen-and B-cell mitogen-induced lymphocyte proliferation, respectively. Further regression analysis performed on the PCB classes measured in this study showed that di-ortho PCBs accounted for 25 and 30% of the changes in both T-cell and B-cell lymphocyte proliferation, respectively. Results suggest that POPs, and PCBs in particular, are associated with changes in lymphocyte proliferation, something that could result in increased susceptibility to infections in harbor seal pups. Further research is needed to evaluate the relative roles of natural and contaminant-related influences on the immune system of marine mammals.

Levels of Persistent Organochlorine Contaminants in Fish from Korea and Their Potential Health Risk

Organochlorine contaminants in the muscles of sport and market fish were determined to understand the potential risks to humans consuming fish originating in Korea's coastal waters. Polychlorinated biphenyls (PCBs; sum of 22 congeners) and DDTs were the dominant contaminants, and their concentrations were in the range of 2.96 to 96.6 and 0.84 to 27.0 ng/g (wet weight basis), respectively. The highest PCB concentrations were found in samples taken from an industrial complex. Hexachlorocyclohexanes, chlordane-related compounds, and hexachlorobenzene concentrations were relatively low and ranged from 0.64 to 5.6, 0.17 to 4.24, and 0.08 to 1.58, respectively. Sport fish had levels of PCBs and DDTs approximately two times higher than market fish, implying that sport fish posed high potential risk of contamination with OCs. Risk-based screening value (SV) based on U. S. Environmental Protection Agency (USEPA) method was calculated using the USEPA approach to identify the primary chemicals of concern. Total PCB concentrations in all sport and market fish exceeded the SV (5.04 ng/g based on total PCBs), but the other compounds were mostly below SV values. Based on the estimated SVs, PCB compounds were identified as potential chemicals of concern.

PCB Congeners and Dechlorination in Sediments of Upper Sheboygan River, Wisconsin

Nine hand-collected sediment cores were obtained for PCB concentration analysis and dating from the Upper Sheboygan River, Wisconsin, USA. The primary PCB Aroclors in the Upper Sheboygan River were 1248 (50%) and 1254 (50%). The total PCB concentrations in the sediments ranged from 0.1–104 ppm (based on dry weight). The PCB data obtained from the sampling were analyzed using a factor analysis (FA) model with non-negative constraints in order to identify PCB sources and congener patterns. The factor loadings obtained from the FA model represent a general dechlorination profile common to most of the higher concentration samples and another associated with contamination from upstream dredging during 1989–1991. Anaerobic dechlorination is occurring in Upper Sheboygan River sediments and is most significant at high concentrations (≥ 20 ppm). Observation of elevated amounts of lower chlorinated congeners such as congeners 4 (2-2), 8 (2-4), 25 (24-3), and 26 (25-3) indicates the presence of anaerobic dechlorination activities. Based on the data from the FA model, anaerobic dechlorination was occurring according to dechlorination activities M and P. All possible dechlorination pathways involving marker congeners were considered. A significant improvement (86–91%) in similarity between the original Aroclor profile and the altered ones was found.

Polybrominated diphenyl ethers and selected organochlorine chemicals in grey seals ( Halichoerus grypus) in the North Sea

Blubber samples from grey seal ( Halichoerus grypus) pups were collected in 1998 through to 2000. Twenty four newly weaned pups were sampled in November 1998, 13 of which were re-sampled during their first year of life, between March and December 1999, and an additional 48 and 25 samples (new cohorts) were obtained in 1999 (November–December) and 2000 (May–September) respectively. ∑PBDE concentrations (sum of Di-HxBDEs) ranged from 45 to 1500 ng/g lipid, with a geometric mean of 290 ng/g lipid. BDE 47 dominated the congener profile, followed by BDEs 100, 99, 153 and 154. ∑PCB concentrations (sum of 41 congeners) ranged from 100 to 93 000 ng/g lipid, with a geometric mean of 4600 ng/g lipid, with CB congeners 153, 138 and 180 making up 84% of the total PCB concentrations. The predominant OC pesticides were p, p′-DDE (geometric mean = 860 ng/g lipid, range = 160–3800 ng/g lipid) and p, p′-DDT (geometric mean = 120 ng/g lipid, range = 30–670 ng/g lipid). No significant differences were found between males and females, probably due to the young age of the animals. Significant decreases ( P < 0.01 for PBDEs and P < 0.05 for PCBs/OCs) were observed between newly weaned seals in 1998 and 1999, but not for the majority of juveniles in 1999 and 2000. Significant differences ( P < 0.01) were also found between the different seasons in 1999 newly weaned and juvenile seals, reflecting changes in blubber mass.

Latitudinal fractionation of polychlorinated biphenyls in surface seawater along a 62 degrees N-89 degrees N transect from the southern Norwegian Sea to the North Pole area.

Surface seawater concentrations of PCBs, relative congener abundance, and possible effects of cold condensation were studied along a transect from the southern Norwegian Sea to the central Arctic Ocean (62 degrees N-89 degrees N). Large volume samples were collected from an ice breaker using a stainless steel surface seawater intake connected online to an ultra-clean laboratory. Concentrations of all studied PCB congeners, except for trichlorinated PCB 18, decreased with latitude. For instance, PCB 52 decreased from 470 fg L(-1) at 62 degrees N to 110 fg L(-1) at 89 degrees N and PCB 180 from 110 to 12 fg L(-1). Concentrations in the central Arctic Ocean were on the order of 10-100 fg L(-1) for the most abundant congeners. The relative contribution oftrichlorinated PCBs to the total PCB concentration increased with latitude, the tetrachlorinated contribution to the total PCBs did not show any correlation to latitude, and the relative contribution of heavier congeners decreased with latitude. This study establishes the occurrence at very low abundances of PCBs in seawater in the central Arctic Ocean and demonstrates a northward concentration decrease. The latitudinal shift in congener pattern is reflecting the relative propensity of the PCB congeners to undergo long-range transport in the Arctic and is consistent with their relative vapor pressures.

Detailed PCB congener patterns in incinerator flue gas and commercial PCB formulations (Kanechlor)

In this study, we determined the detailed PCB congener patterns in flue gases from eight incinerators and four commercial PCB formulations (Kanechlors). About 160 PCB peaks were identified in samples using a DB-5 column and HRGC/HRMS. The concentration of incinerator stack emission gas ranged from 0.02 to 44 ng WHO-TEQ/N m 3. The ratios of dioxin-like PCBs in the total PCB concentration were from 3.4% to 25.7% and from 0.63% to 9.1% in stack emission gases and Kanechlor samples, respectively. The PCB congener profiles of Kanechlor samples were similar to those of previous studies. To determine characteristic congeners in flue gas and Kanechlor samples, principal component analysis (PCA) of the data was conducted using STATISTICA for Windows 5.0J (StatSoft, Inc.). As a result, we obtained four principal components (PCs) and accounted for 74% of the total variance. PC 1 was interpreted combustion, PC 2 and PC 3 were interpreted the difference in the number of substituted chlorines and, PC 4 could not be determined. Moreover, we obtained three groups according to the PCB congeners pattern among samples by PCA. These specific congeners that represent characteristics of each class were identified. These data will be useful for the source analysis of PCBs in the environment.

Prediction of PCB Content in Sportfish Using Semipermeable Membrane Devices (SPMDs)

Triolein-filled semipermeable membrane devices (SPMDs) were immersed at three locations along the St. Joseph River in northern Indiana for 30 days to see if the PCB content of fish from the same location could be predicted with this model device. Triolein from the SPMD's was analyzed for PCB using enzyme-linked immunosorbent assay (ELISA) and compared to residues detected in fish collected from the same locations. There was a significant difference (p < 0.05) in total PCB concentrations between SPMD samples. However, due to variability in PCB residues between species and low PCB residues in SPMDs, a direct correlation between PCBs in sportfish and SPMDs could not be determined.

Contaminants in molting long-tailed ducks and nesting common eiders in the Beaufort Sea

In 2000, we collected blood from long-tailed ducks ( Clangula hyemalis) and blood and eggs from common eiders ( Somateria mollissima) at near-shore islands in the vicinity of Prudhoe Bay, Alaska, and at a reference area east of Prudhoe Bay. Blood was analyzed for trace elements and egg contents were analyzed for trace elements, organochlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. Except for Se (mean=36.1 μg/g dry weight (dw) in common eiders and 48.8 μg/g dw in long-tailed ducks), concentrations of trace elements in blood were low and, although several trace elements differed between areas, they were not consistently higher at one location. In long-tailed ducks, Se in blood was positively correlated with activities of two serum enzymes, suggestive of an adverse effect of increasing Se levels on the liver. Although common eiders had high Se concentrations in their blood, Se residues in eggs were low (mean=2.28 μg/g dw). Strontium and Ni were higher in eggs near Prudhoe Bay than at the reference area, but none of the other trace elements or organic contaminants in eggs differed between locations. Concentrations of Ca, Sr, Mg, and Ni differed among eggs having no visible development, early-stage embryos, or late-stage embryos. Residues of 4,4 ′-DDE, cis-nonachlor, dieldrin, hexachlorobenzene, oxychlordane, and trans-nonachlor were found in 100% of the common eider eggs, but at low concentrations (means of 2.35–7.45 μg/kg wet weight (ww)). The mean total PCB concentration in eggs was 15.12 μg/kg ww. Of PAHs tested for, residues of 1- and 2-methylnaphthalene and naphthalene were found in 100% of the eggs, at mean concentrations of 0.36–0.89 μg/kg ww.

Congener-based Aroclor quantification and speciation techniques: a comparison of the strengths, weaknesses, and proper use of two alternative approaches.

This paper compares two previously published methods, an Aroclor estimation method and a mixing model method, that relate Aroclor contamination to congener specific data in environmental samples. The Aroclor estimation method, which is consistent with U.S. EPA Method 8082, uses a limited set of congener specific data to estimate Aroclor contributions to the sample, while the mixing model method uses the full congener data to model sample compositions as linear combinations of Aroclors. The performance of these methods are compared, using 181 samples at a variety of trophic levels, in terms of (a) total PCB concentrations, (b) compositional modification levels from original Aroclors, and (c) determination of the Aroclor mixture or mixtures best describing the sample (Aroclor speciation). We find that the two methods agree in all three terms for samples of low trophic level, but disagree for samples of higher tropic levels. Most significantly, the comparison reveals systematic overestimation of total PCB content by the Aroclor estimation method for samples at high trophic levels. The implication is that Aroclor determinations using persistent congeners cannot reliably be used as surrogates for total PCB concentration. The strengths and weaknesses of each method are detailed.

Persistent organochlorine pollutants in liver of birds of different trophic levels from coastal areas of Campania, Italy.

Liver samples of 12 species of birds of different trophic levels, collected during the period 1998-2000 from coastal areas of the Campania region, Southern Italy, were analyzed for organochlorine pesticides (OCs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), gamma-hexachlorocycloexane (gamma-HCH), aldrin, dieldrin, endrin, and the seven PCB "target" congeners, IUPAC Nos. 28, 52, 101, 118, 138, 153 and 180. p,p'-DDE was present in all the samples analyzed, at concentrations ranging from 4 to 4504 ng/g wet wt, which were much higher than those found for HCB, dieldrin, and p,p'-DDD. The concentrations of the others OCs were below the detection limit in all the samples. PCBs were found in all the bird species at levels ranging between 6 and 8431 ng/g wet wt. The hepta-, hexa-, and penta-chlorinated congeners 180, 153, 138, and 118 were predominant since, in almost all the species, they contributed to more than 98% of the total seven determined PCBs. No significant differences in mean concentrations of organochlorine pesticides are detected between single species or between species grouped according to their feeding habits (p > 0.05). However, p,p'-DDE levels were higher in carnivorous species than in omnivorous and insectivorous ones (carnivorous > omnivorous > insectivorous). Concentrations of total PCBs were significantly higher in omnivorous birds than in carnivorous (p < 0.01) and insectivorous ones (p < 0.001), whereas carnivorous birds exhibited significantly higher total PCB levels than insectivorous ones (p < 0.01). Marked differences in total PCB concentrations were found also between single species (from p < 0.05 to p < 0.001). Levels of OCs and PCBs were generally below the thresholds known to affect reproduction, however, mean hepatic concentrations of total PCBs in the yellow-legged herring gull (Larus cachinnans), black-headed gull (Larus ridibundus), and kestrel (Falcus tinnunculus) were far higher than those estimated to elicit immunosuppressive effects and possibly increase susceptibility to parasitoses.

Time trends of selected persistent organic pollutants in lake sediments from Greenland.

Sediments from seven lakes in West Greenland were used as natural archives to study past and present levels of PCBs (polychlorinated biphenyls, tri- to decachlorinated), tetra-BDE #47 (2,2',4,4'-bromodiphenyl ether), chlordane (cis- and trans-octachlordane) and HxCBz (hexachlorobenzene). The concentrations found are lower than or comparable to concentrations found in sediments from other Arctic regions and one to 2 orders of magnitude lower than concentrations typically found in sediments at lower latitudes. The observed temporal trends (direct and indirect dating) show a decreasing total PCB concentration. Even though local contamination sources exist, the POP deposition in the studied area is most likely a result from long-range transport. The hypothesis about "cold condensation" suggests a latitudinal fractionation to occur between different volatile compounds during the transport toward the pole. In this study a time delay in the deposition for the low-chlorinated PCBs (tri- and tetrachlorinated), compared to their emission histories and compared to higher chlorinated PCBs, was indicated. Although very low tetra-BDE #47 concentrations are observed in this study, there are indications for an increasing concentration in recent sediment layers that may reflect increasing environmental concentrations at lower latitudes. The investigated pesticides are still in use at lower latitudes, however neither chlordane nor HxCBz show any distinct temporal trend of increasing or decreasing concentration toward the sediment surface.

Screening of Polychlorinated Biphenyls in Water Samples by Strategic Sample Composition-Solid Phase Extraction and Gas Chromatography Tandem Mass Spectrometry. Comparison of Different Strategies for Sample Composition

Strategic Sample Composition (SSC) is a new sample composition technique that allows the reduction of the number of analytical determinations to be carried out in screening campaigns down to the very number of the original sample specimens while providing information particularised to the original sample specimens instead of average information. The application of this technique in environmental screening studies is shown. Technical mixtures of polychlorinated biphenyls (Aroclors) have been chosen as model contaminants in water samples to show the usefulness and potential of the SSC technique in this field. EPA 1668/1668a protocols were used for sample treatment. Gas chromatography hyphenated to tandem mass spectrometry was used for the analysis of the samples. Two types of sample composition design matrices (a conventional Plackett-Burman screening matrix and a supersaturated matrix) were used and compared in the study. A total of 22 sample specimens were considered. Four of these sample specimens were contaminated at levels between 200 and 750 ng/L (total PCB concentration). A total of 24 experiments are needed to process these 22 sample specimens when applying the conventional Plackett-Burman matrix. Comparatively, only 13 analytical determinations are needed when using the supersaturated matrix. Both types of matrices allow clear identification of the contaminated sample specimens and produced satisfactory estimations of their concentration levels. Special emphasis has been put in investigating and demonstrating the robustness of the SSC technique.

PAHs, PCBs, PCNs, organochlorine pesticides, synthetic musks, and polychlorinated n-alkanes in U.K. sewage sludge: survey results and implications.

A survey of the digested sludge from 14 U.K. wastewater treatment plants was carried out to obtain contemporary U.K. data on the concentrations of certain classes of persistent organic compounds for which data are scarce and to assess whether U.K. sludge was likely to comply with the sludge limits for PCBs and PAHs proposed by the European Union. Total PAH (24 compounds) concentrations ranged from 67 to 370 mg/kg dw, in line with data from other countries; all the samples would exceed the proposed EU limit. Total PCB concentrations were 110-440 microg/kg dw, well below the proposed EU limit. Total PCN concentrations ranged from 50 to 190 microg/kg. Total synthetic musk concentrations ranged from 2.1 to 86 mg/kg dw; there were a few very high concentrations of HHCB and AHTN in the samples. Total concentrations of the short- and medium-chained polychlorinated alkanes ranged between 7 and 200 mg/kg and between 30 and 9700 mg/kg, respectively. These very high concentrations are indicative of chemicals with numerous and ongoing diffuse sources.

Chorioallantoic Membranes Indicate Avian Exposure and Biomarker Responses to Environmental Contaminants: A Laboratory Study with White Leghorn Chickens (Gallus domesticus)

PCB and endosulfan concentrations in the chorioallantoic membrane (CAM) of white leghorn chickens (Gallus domesticus) were evaluated as indicators of hepatic cytochrome P450 isozyme activity in hens and chicks as well as toxicant concentrations in eggs and hens. Sixteen hens were randomly divided into four groups of four and dosed with a mixture of PCB105 (2,3,3',4,4'-pentachlorobiphenyl), PCB156(2,3,3',4,4',5-hexachlorobiphenyl), PCB189 (2,3,3',4,4',5,5'-heptachlorobiphenyl), and technical grade endosulfan (3:1 ratio of alpha and beta isomers) at three different dose groups. The first 10 fertile eggs laid by each hen were collected, the even-numbered eggs incubated until hatched, and the odd numbered eggs were analyzed for test chemicals. Strong (r2), significantly positive (p value) relationships were found between total PCB mass (ng) in CAMs and both total PCB concentrations (ng/g wet wt) in adults (r2 = 0.91, p = 0.0001) and eggs (r2 = 0.87, p = 0.0001). The relationship between total PCB mass in CAMs and hepatic cytochrome p450 isozyme activity in chicks (r2 = 0.49, p = 0.0001) and hens (r2 = 0.45, p = 0.014) was also significant but not as strong. This study shows that CAMs can be used to estimate avian exposure to PCBs and resultant biological response.

Organochlorine pesticides and PCB residues in sediments of Alexandria Harbour, Egypt

Persistent organochlorine compound concentrations were determined for 23 surface sediment samples collected from Alexandria Harbor, Egypt. Total PCB concentrations ranged from 0.9 to 1210 ng/g with four to seven Cl-substituted biphenyls being the most prevalent PCBs congeners. Different PCB congener distribution patterns were observed, probably reflecting different inputs and attenuation at various locations. Total DDT concentrations varied from <0.25 ng/g to 885 ng/g. The ratios of DDTs (2,4 ′- and 4,4 ′-DDT)/total DDTs (DDTs plus metabolites) in sediment samples from certain sites were 0.86 or higher, indicating little attenuation or recent input of DDT. Total chlordane (the sum of heptachlor and its epoxide, oxy-, γ- and α-chlordane and cis+ trans-nonachlor) ranged from <0.25 to 44 ng/g with the highest concentration found in the Arsenal Basin. The geographic distributions of PCBs, total DDTs and total chlordane were similar. Chlorinated benzenes (CBs), hexachlorocyclohexanes (HCHs), aldrin, dieldrin, endrin, chloropyrifos, endosulfan, mirex and pentachloroanisole were below detection limits or detected at low concentrations in most of the samples. Sites that were contaminated with high concentrations of organochlorine compounds were associated with dense population and low energy environment. The contamination levels of PCBs, total DDTs and total chlordane were in high range compared to other locations worldwide.