Environmental PCB Research Articles

Resistance to Cyp3a induction by polychlorinated biphenyls, including non-dioxin-like PCB153, in gills of killifish (Fundulus heteroclitus) from New Bedford Harbor

Previous reports suggested that non-dioxin-like (NDL) PCB153 effects on cytochrome P450 3A (Cyp3a) expression in Atlantic killifish (Fundulus heteroclitus) gills differed between F0 generation fish from a PCB site (New Bedford Harbor; NBH) and a reference site (Scorton Creek; SC). Here, we examined effects of PCB153, dioxin-like (DL) PCB126, or a mixture of both, on Cyp3a56 mRNA in killifish generations removed from the wild, without environmental PCB exposures. PCB126 effects in liver and gills differed between populations, as expected. Gill Cyp3a56 was not affected by either congener in NBH F2 generation fish, but was induced by PCB153 in SC F1 fish, with females showing a greater response. PCB153 did not affect Cyp3a56 in liver of either population. Results suggest a heritable resistance to NDL-PCBs in killifish from NBH, in addition to that reported for DL PCBs. Induction of Cyp3a56 in gills may be a biomarker of exposure to NDL PCBs in fish populations that are not resistant to PCBs.

In vitro profiling of toxic effects of prominent environmental lower-chlorinated PCB congeners linked with endocrine disruption and tumor promotion

The mechanisms contributing to toxic effects of airborne lower-chlorinated PCB congeners (LC-PCBs) remain poorly characterized. We evaluated in vitro toxicities of environmental LC-PCBs found in both indoor and outdoor air (PCB 4, 8, 11, 18, 28 and 31), and selected hydroxylated metabolites of PCB 8, 11 and 18, using reporter gene assays, as well as other functional cellular bioassays. We focused on processes linked with endocrine disruption, tumor promotion and/or regulation of transcription factors controlling metabolism of both endogenous compounds and xenobiotics. The tested LC-PCBs were found to be mostly efficient anti-androgenic (within nanomolar – micromolar range) and estrogenic (at micromolar concentrations) compounds, as well as inhibitors of gap junctional intercellular communication (GJIC) at micromolar concentrations. PCB 8, 28 and 31 were found to partially inhibit the aryl hydrocarbon receptor (AhR)-mediated activity. The tested LC-PCBs were also partial constitutive androstane receptor (CAR) and pregnane X receptor (PXR) agonists, with PCB 4, 8 and 18 being the most active compounds. They were inactive towards other nuclear receptors, such as vitamin D receptor, thyroid receptor α, glucocorticoid receptor or peroxisome proliferator-activated receptor γ. We found that only PCB 8 contributed to generation of oxidative stress, while all tested LC-PCBs induced arachidonic acid release (albeit without further modulations of arachidonic acid metabolism) in human lung epithelial cells. Importantly, estrogenic effects of hydroxylated (OH-PCB) metabolites of LC-PCBs (4-OH-PCB 8, 4-OH-PCB 11 and 4′-OH-PCB 18) were higher than those of the parent PCBs, while their other toxic effects were only slightly altered or suppressed. This suggested that metabolism may alter toxicity profiles of LC-PCBs in a receptor-specific manner. In summary, anti-androgenic and estrogenic activities, acute inhibition of GJIC and suppression of the AhR-mediated activity were found to be the most relevant modes of action of airborne LC-PCBs, although they partially affected also additional cellular targets.

Developmental exposure to an environmental PCB mixture delays the propagation of electrical kindling from the amygdala

Developmental PCB exposure impairs hearing and induces brainstem audiogenic seizures in adult offspring. The degree to which this enhanced susceptibility to seizure is manifest in other brain regions has not been examined. Thus, electrical kindling of the amygdala was used to evaluate the effect of developmental exposure to an environmentally relevant PCB mixture on seizure susceptibility in the rat. Female Long-Evans rats were dosed orally with 0 or 6mg/kg/day of the PCB mixture dissolved in corn oil vehicle 4 weeks prior to mating and continued through gestation and up until postnatal day (PND) 21. On PND 21, pups were weaned, and two males from each litter were randomly selected for the kindling study. As adults, the male rats were implanted bilaterally with electrodes in the basolateral amygdala. For each animal, afterdischarge (AD) thresholds in the amygdala were determined on the first day of testing followed by once daily stimulation at a standard 200μA stimulus intensity until three stage 5 generalized seizures (GS) ensued. Developmental PCB exposure did not affect the AD threshold or total cumulative AD duration, but PCB exposure did increase the latency to behavioral manifestations of seizure propagation. PCB exposed animals required significantly more stimulations to reach stage 2 seizures compared to control animals, indicating attenuated focal (amygdala) excitability. A delay in kindling progression in the amygdala stands in contrast to our previous finding of increased susceptibility to brainstem-mediated audiogenic seizures in PCB-exposed animals in response to a an intense auditory stimulus. These seemingly divergent results are not unexpected given the distinct source, type, and mechanistic underpinnings of these different seizure models. A delay in epileptogenesis following focal amygdala stimulation may reflect a decrease in neuroplasticity following developmental PCB exposure consistent with reductions in use-dependent synaptic plasticity that have been reported in the hippocampus of developmentally PCB exposed animals.

Additive modelling reveals spatiotemporal PCBs trends in marine sediments

We developed generalised additive mixed models (GAMMs) to infer spatiotemporal trends of environmental PCB concentrations from an extensive dataset (n=1219) of PCB concentrations measured between 1991 and 2010 in sediments of the Belgian Coastal Zone (BCZ) and the Western Scheldt estuary. A GAMM with time, geographical zone, periodicity and the organic carbon – water partition coefficient as covariates explained 49% of the variability in the log transformed PCB sediment concentrations. The time trends unraveled two to threefold PCB concentration decreases in the BCZ during the last 20years. However, in the Western Scheldt estuary, time trends were spatially heterogeneous and not significantly decreasing. These results demonstrate that international efforts to cut down emissions of PCBs have been effective to reduce concentrations in open water ecosystems like the BCZ but had little effect in the urbanised and industrialised area of the Scheldt estuary.

Ten years of progress in the Hokkaido birth cohort study on environment and children’s health: cohort profile—updated 2013

The Hokkaido Study on Environment and Children's Health is an ongoing cohort study that began in 2002. The study consists of two prospective birth cohorts, the Sapporo cohort (n = 514) and the Hokkaido large-scale cohort (n = 20,940). The primary goals of this study are to first examine the potential negative effects of perinatal environmental chemical exposures on birth outcomes, including congenital malformations and growth retardation; second, to evaluate the development of allergies, infectious diseases and neurodevelopmental disorders and perform longitudinal observations of the children's physical development to clarify the causal relationship between these outcomes and environmental chemicals; third, to identify individuals genetically susceptible to environmental chemicals; finally, to identify the additive effects of various environmental factors in our daily life, such as secondhand smoke exposure or low folate intake during early pregnancy. In this paper, we introduce our recent progress in the Hokkaido study with a cohort profile updated in 2013. For the last ten years, we followed pregnant women and their offspring, measuring various environmental chemicals, i.e., PCB, OH-PCB and dioxins, PFCs (Perfluorinated Compounds), Organochlorine pesticides, Phthalates, bisphenol A and mercury. We discovered that the concentration of toxic equivalents (TEQ) of dioxin and other specific congeners of PCDF or PCDD have effects on birth weight, infants' neurodevelopment and immune function. There were significant gender differences in these effects; our results suggest that male infants have more susceptibility to those chemical exposures than female infants. Interestingly, we found maternal genetic polymorphisms in AHR, CYP1A1 or GSTs that significantly modified the dioxin concentrations in maternal blood, suggesting different dioxin accumulations in the bodies of individuals with these genotypes, which would lead to different dioxin exposure levels. These genetic susceptibility factors influenced the body size of children born from mothers that either smoked or were passively exposed to tobacco smoke. Further studies investigating the correlation between epigenetics, the effects of intrauterine exposure to environmental chemicals and developmental factors related to health and disease are warranted.

Comparative assessment of polychlorinated biphenyls’ toxic potential in ovary cells

PCBs are considered as potential endocrine disruptors with various deleterious effects on female reproductive system. Although, the environmental PCB levels have been declining due to legislation, in the Republic of Croatia risk is still high due to destructions of the facilities containing PCBs during the Patriotic War (1991–1995). The toxic profiles of PCBs are congener-specific and the major structural factor in determining the toxic properties is the presence of chlorine atom in ortho position. A comparative assessment of dioxin-like, coplanar PCB 77 and non-dioxin-like, ortho-substituted PCB 153 effects has been performed in this study to evaluate the potential risk and mode of action for inducing cytotoxicity in Chinese hamster ovary cells. In order to assess and quantify toxic effects of PCBs (10–100 μM) three in vitro methods with distinct endpoints were chosen: Trypan blue (TB), Neutral red (NR) and Kenacid blue assays (KB). Overall, a dose dependent cytotoxicity for PCB-77 was confirmed with all assays applied, whereas for PCB-153 only with TB and NR. Extent of the cellular viability loss and accelerated cell death were greater for non-ortho-substituted PCB-77 (after 72 h: IC50-TB = 24.0 μM ; IC50-NR = 55.4 μM ; IC50-KB = 94.2 μM) than for di-ortho-substituted congener PCB-153 (after 72 h: IC50-TB = 55.5 μM ; IC50-NR = 51.0 μM ; IC50-KB = 111.1 μM). To determine if exposure to PCBs perturbs cellular proliferation, CHO-K1 cells were incubated with 50 μM PCB-77 or PCB-153 for 6 or 48 h and assayed for cell cycle phase distributions using flow cytometry. Major induced alterations were detected for PCB 77 with a slight increase in apoptotic peak vs. no observed effect for PCB-153.

ISCHEMIC STROKE AND FISH CONSUMPTION IN SOUTHERN SWEDEN

Background and Aims: Fish intake can have both beneficial effects (via omega-3 fatty acids) and adverse effects (via the environmental pollutants methyl mercury and PCB). Quite a few researchers have reported fish intake to reduce stroke risk, but there have also been inconsistencies in results; high fish consumption have for example been observed to increase stroke risk in men from northern Sweden. We aimed at studying lean and fat fish consumption as a risk factor for ischemic stroke in southern Sweden, separately for men and women. Methods: Data on fish intake and other variables were obtained from an already available population based case-control study, with incident first-time ischemic stroke patients. Complete data on all relevant variables were obtained for 2718 controls and 2455 cases. The data were analyzed with logistic regression analysis. Results: Stroke risk decreased with fat fish intake (• 1/week versus <1/month) in both men and women; adjusted Odds Ratio (OR) 0.69, 95% Confidence Interval...

A non-invasive approach to study lifetime exposure and bioaccumulation of PCBs in protected marine mammals: PBPK modeling in harbor porpoises

In the last decade, physiologically based pharmacokinetic (PBPK) models have increasingly been developed to explain the kinetics of environmental pollutants in wildlife. For marine mammals specifically, these models provide a new, non-destructive tool that enables the integration of biomonitoring activities and in vitro studies. The goals of the present study were firstly to develop PBPK models for several environmental relevant PCB congeners in harbor porpoises ( Phocoena phocoena), a species that is sensitive to pollution because of its limited metabolic capacity for pollutant transformation. These models were tested using tissue data of porpoises from the Black Sea. Secondly, the predictive power of the models was investigated for time trends in the PCB concentrations in North Sea harbor porpoises between 1990 and 2008. Thirdly, attempts were made to assess metabolic capacities of harbor porpoises for the investigated PCBs. In general, results show that parameter values from other species (rodents, humans) are not always suitable in marine mammal models, most probably due to differences in physiology and exposure. The PCB 149 levels decrease the fastest in male harbor porpoises from the North Sea in a time period of 18 years, whereas the PCB 101 levels decrease the slowest. According to the models, metabolic breakdown of PCB 118 is probably of lesser importance compared to other elimination pathways. For PCB 101 and 149 however, the presence of their metabolites can be attributed to bioaccumulation of metabolites from the prey and to metabolic breakdown of the parent compounds in the harbor porpoises.

Recombinant cell bioassays for the detection of (gluco)corticosteroids and endocrine-disrupting potencies of several environmental PCB contaminants.

Sensitive and robust bioassays for glucocorticoids are very useful for the pharmaceutical industry, environmental scientists and veterinary control. Here, a recombinant yeast cell was constructed that expresses the human glucocorticoid receptor alpha and a green fluorescent reporter protein in response to glucocorticoids. Both the receptor construct and the reporter construct were stably integrated into the yeast genome. The correct and specific functioning of this yeast glucocorticoid bioassay was studied by exposures to cortisol and other related compounds and critically compared to a GR-CALUX bioassay based on a human bone cell. Although less sensitive, the new yeast glucocorticoid bioassay showed sensitivity towards all (gluco)corticoids tested, with the following order in relative potencies: budesonide >> corticosterone > dexamethasone > cortisol = betamethasone > prednisolone > aldosterone. Hormone representatives for other hormone nuclear receptors, like 17β-estradiol for the oestrogen receptor, 5α-dihydrotestosterone for the androgen receptor and progesterone for the progesterone receptor, showed no clear agonistic responses, whilst some polychlorinated biphenyls were clearly able to interfere with the GR activity.

High vertical and low horizontal diversity of Prochlorococcus ecotypes in the Mediterranean Sea in summer

Natural populations of the marine cyanobacterium Prochlorococcus exist as two main ecotypes, inhabiting different layers of the ocean's photic zone. These so-called high light- (HL-) and low light (LL-) adapted ecotypes are both physiologically and genetically distinct. HL strains can be separated into two major clades (HLI and HLII), whereas LL strains are more diverse. Here, we used several molecular techniques to study the genetic diversity of natural Prochlorococcus populations during the Prosope cruise in the Mediterranean Sea in the summer of 1999. Using a dot blot hybridization technique, we found that HLI was the dominant HL group and was confined to the upper mixed layer. In contrast, LL ecotypes were only found below the thermocline. Secondly, a restriction fragment length polymorphism analysis of PCR-amplified pcb genes (encoding the major light-harvesting proteins of Prochlorococcus) suggested that there were at least four genetically different ecotypes, occupying distinct but overlapping light niches in the photic zone. At comparable depths, similar banding patterns were observed throughout the sampled area, suggesting a horizontal homogenization of ecotypes. Nevertheless, environmental pcb gene sequences retrieved from different depths at two stations proved all different at the nucleotide level, suggesting a large genetic microdiversity within those ecotypes.

Manufacturing an environmentally friendly PCB using existing industrial processes and equipment

This paper investigates the possibility of utilising an additive screen printing process with conductive ink and adhesive together with a degradable substrate to identify whether this process offers a viable alternative to current subtractive methods of PCB manufacture. Existing manufacturing equipment and production process were adopted in order to establish the compatibility of a sustainable and environmental friendly PCB with these processes. Experimental trials have shown that by using a stainless steel stencil 150 mm thick in conjunction with an MPM Ultraprint machine with a printing speed of 89 mm/s, a squeegee pressure of 0.97 bar and a downstop of 1.9 mm successful printing of the electrically conductive adhesive was achieved. It was also shown that the substrate was compatible with electronic placement technology and convection oven. Comparisons of the electronic assemblies to an industrial IPC standard illustrated that it is possible to develop a circuit, which is deemed acceptable under this standard. It can be concluded therefore that a screen printed conductive ink pattern, when printed on a degradable substrate can offer a viable alternative to current printed circuit boards and can be manufactured using existing technology and manufacturing processes.

Neurobehavioral Endpoints in Children Affected by Environmental Polychlorinated Biphenyls

MAA2-PD-13 Introduction: The aim of this study was to contribute to the knowledge of neurobehavioral changes in children 8 to 9 years of age (n = 435). Methods: Neurobehavioral examinations included sensomotor integration, eye–hand coordination, attention, and memory and cognitive processes. A general health/social questionnaire and behavioral scale were filled in by parents and the behavior at school was evaluated by teacher. Statistical analysis involved 3 types of data evaluation: The PCBs serum concentrations and selected heavy metals (Pb, Mn, Hg, in whole blood) also were determined. The PCB level was positively skewed and normalized by a natural logarithmic transformation (Ln) and calculated in quartiles for descriptive purposes. Correlation coefficients were calculated between dependent neurobehavioral variables and both the exposure level of PCBs and confounding variables (<0.05). To test for the validity of these correlations, we conducted multiple linear regression analyses to adjust for confounding. Results: The σPCB-concentrations in serum ranged from 1692.8 to 257.5 ng/g lipids; higher levels were found close to the PCBs source, a former PCB-production plant. Significantly poorer sensomotor performances were found in preliminary evaluations in children with higher PCB levels (fourth quartile of PCB) but were no longer apparent after adjustment for schools or residential areas. Older age and greater maternal intelligence were associated with better performances in cognitive and some sensomotor tests. Previous findings of an inverse influence of preperinatal PCBs on neurobehavioral performances were confirmed only if study area and schools were not included in the full regression model. The outcome of neuropsychological tests and scales of behavior were included into this analysis as dependent variables, and a selected set of covariates, including PCBs in serum concentrations, were used as independent predictors. Because the 2 areas and the schools within areas differed for both exposure and several of the outcome variables exposure-outcome associations were additionally adjusted for “area” “schools” and “area plus schools” in the multifactor regression analysis. The final regression models included the set of variables (σPCBs, neurobehavioral and social). Discussion and Conclusions: The results suggest that postnatal or concurrent exposure to PCBs does not exhibit inverse association with neurobehavior if study area is taken into consideration in the full regression model. This outcome must be compared with well-established findings of neurobehavioral adversity of environmental PCB exposure in relation to preperinatal exposure and emphasizes the higher vulnerability of the developing relative to the mature brain.

Alterations in DRH and DRL performance in rats developmentally exposed to an environmental PCB mixture

Schedule-controlled responding was examined in offspring of rats exposed to a PCB mixture formulated to mimic the PCB congener profile in fish from the Fox River in Green Bay, WI. Female rats were administered 0, 1, 3, or 6 mg/kg/day of the PCB mixture beginning four weeks prior to breeding until weaning on postnatal day 21. When offspring were approximately 235 days old, they were tested on three different schedules of a differential reinforcement of high rate (DRH) operant task (DRH 2:1, DRH 4:2, and DRH 8:4). DRH testing was followed by testing on the differential reinforcement of low rate (DRL) operant task in which rats had to inhibit responding until 15 s had elapsed (DRL 15) from the previous response in order to obtain a food reinforcer. After completion of DRL 15 testing, 3 days of extinction testing were conducted (DRL EXT) during which no reinforcers were delivered. Developmental exposure to the higher PCB doses resulted in shorter inter-response times (IRTs) and shorter response durations during DRH 8:4, which translated into a greater percentage of reinforced trials. For DRL 15, no significant exposure-related effects were observed on the number of responses or reinforcers earned, or the number or proportion of responses with long or short inter-response times during acquisition or steady state performance. However, during DRL EXT, rats developmentally exposed to the highest PCB dose responded more than controls, produced significantly more short IRT responses, and had a significantly lower proportion of long IRT responses. Overall, exposure to this PCB mixture resulted in increased responding which was suggestive of a deficit in inhibitory control.

Polychlorinated Biphenyls (PCB 153 and PCB 126) Action on Conversion of 20-Hydroxylated Cholesterol to Progesterone, Androstenedione to Testosterone, and Testosterone to Estradiol 17β

To look for one of the possible mechanisms of action we investigated the effect of two congeners of polychlorinated biphenyls (PCB153 as one of the most prominent environmental contaminants and PCB 126 as one of the most toxic contaminants similar to dioxin) on the cellular conversion of steroid precursors as an indicator for enzyme activity (20-hydroxylated cholesterol to progesterone for P450 (scc,) androstendione to testosterone for 17-beta-HSD, and testosterone to estradiol for P450 (arom)). The net synthesis and secretion of particular steroids was used as the indicator of enzyme activity. Co-culture of pig granulosa and theca cells isolated from small (SF) and large (LF) follicles, was carried out in medium M199 supplemented with 100 ng/ml of PCB 153 or 100 pg/ml of PCB 126. The inhibitory action of both PCB 126 and PCB 153 on progesterone secretion by cells isolated from SF and LF follicles was reversed in the presence of 20-hydroxylated cholesterol. The addition of PCB 126 into the culture medium caused a decrease in testosterone secretion by cells isolated from both SF and LF and this effect was reversed in the presence of androstendione. The inhibitory action of PCB 153 on testosterone secretion was reversed by the addition of androstendione to the culture medium in SF, while it caused even additional stimulatory action on cells collected from LF. No effect of PCB 126 and statistically significant decrease in estradiol secretion by cells collected from SF under the influence of PCB153 was observed. The inhibitory effect of PCB 153 was reversed when the culture was supplemented with testosterone. The opposite effect of both tested congeners on estradiol secretion in both basal and testosterone supplemented culture was seen in LF. PCB 126 increased it while PCB 153 decreased both, the basal and testosterone-stimulated estradiol secretion. In conclusion, the presented results suggest that the effect of both PCBs on steroid secretion observed in an early stage of the follicular phase of the estrus cycle is due to the inhibition of cholesterol mobilisation and thus insufficient substrate availability for hormone synthesis. On the contrary, in large preovulatory follicles inhibition of testosterone secretion is due to their action on 17-beta-HSD while stimulatory or inhibitory action on estradiol secretion is the result of their action on P450 aromatase activity.

Contribution of Planar (0–1 Ortho) and Nonplanar (2–4 Ortho) Fractions of Aroclor 1260 to the Induction of Altered Hepatic Foci in Female Sprague–Dawley Rats

The hepatic tumor promoting activity of the planar 0–1 ortho (∼9.7% w/w) and the nonplanar 2–4 ortho (∼90.3% w/w) fraction of the commercial PCB mixture Aroclor 1260 was studied using a medium-term two-stage initiation/promotion bioassay in female Sprague–Dawley rats. Fractionation was carried out on an activated charcoal column. The composition of the effluent from the column was tested by GC–ECD. The absence of planar compounds in the 2–4 ortho fraction was confirmed by GC–MS analysis. The dioxin-like toxic potency of the fractions was determined with the DR-CALUX assay. The animal experiment was started with the initiation procedure (diethylnitrosamine injection, 30 mg/kg body wt ip, 24 h after 2/3 hepatectomy), followed 6 weeks later by the promotion treatment, which consisted of a weekly subcutaneous injection during 20 weeks. Exposure groups (n = 10) received the following treatments (dose/kg body wt/week): Aroclor 1260 (10 mg), 0–1 ortho fraction (0.97 mg), 2–4 ortho fraction (1, 3, or 9 mg), a reconstituted 0–4 ortho fraction (9.97 mg), 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB 153; 1 or 9 mg), 2,3,7,8-TCDD (1 μg; positive control) or corn oil (1 ml; vehicle control). One group did not receive a promotion treatment. All exposure groups exhibited a significantly increased volume fraction of the liver occupied by hepatic foci positive for the placental form of glutathione-S-transferase-p compared to the corn oil control, except for the groups treated with 0–1 ortho fraction and 1 mg PCB 153/kg body wt/week. Approximately 80% of the total tumor promoting capacity of the reconstituted 0–4 ortho fraction could be explained by the 2–4 ortho PCB fraction while the 0–1 ortho fraction had only a negligible contribution. These results suggest that the majority of the tumor promotion potential of PCB mixtures resides in the non-dioxin-like fraction, which is not taken into account in the toxic equivalency factor (TEF) approach for risk assessment of PCBs. This may result in an underestimation of the tumor promotion potential of environmental PCB mixtures.

Proliferation of maxillary and mandibular periodontal squamous cells in mink fed 3,3',4,4',5-pentachlorobiphenyl (PCB 126).

This report characterizes squamous cell proliferation in young farm mink (Mustela vison) fed a diet supplemented with 0.024 ppm 3,3',4,4',5-pentachlorobiphenyl (polychlorinated biphenyl [PCB] congener 126). One to 2 months of dietary exposure to PCB 126 resulted in gross lesions of the upper and lower jaws consisting of mandibular and maxillary nodular proliferation of the gingiva and loose teeth. The maxilla and mandible of the PCB-treated mink were markedly porous because of loss of alveolar bone. Histologically, this osteoporosis was caused by proliferation of squamous cells that formed infiltrating cords. This report clearly documents the fact that the environmental contaminant PCB 126 can cause osteoinvasive squamous proliferation in young mink, although the dose used in the present study was 7 and 36 times higher than what is typically encountered in contaminated bird eggs and fish, respectively.

The bioaccumulation pattern of organochlorine residues in Lanice conchilega (polychaeta) and its geographical variation between the English channel and the German bight

PCBs, p,p′-DDE, HCB, α-HCH and γ-HCH were analysed in Lanice conchilega from the French, Dutch and German coasts. The annelid exhibited a species-specific PCB pattern. It showed lower and higher chlorinated congeners in more balanced quantities than the polychaete Nereis diversicolor and also the bivalve Mytilus galloprovincialis used in the French mussel watch programme RNO. The PCB pattern in L. conchilega was influenced by the geographical location, probably by changes of the environmental PCB composition from SW to NE. Riverine influences could be distinguished from regional ones. Contributions of higher chlorinated PCB congeners increasing from western to eastern river-related positions are explained by fractionation of PCBs during atmospheric transport. Concentrations of PCBs and p,p′-DDE in L. conchilega based on extractable organic matter were highest in the Seine Bay indicating a substantial input of these pollutants by the river Seine. No enhanced PCB and p,p′-DDE values were measured in the German Bight. Levels of γ-HCH and ratios of γ-HCH/α-HCH were elevated near the mouths of Rance and Seine, which drain areas of intensive agriculture with apparent lindane application. Balanced levels of HCB point to fast atmospheric transport and homogenous deposition of this compound into the sea.

Chlorobiphenyl (PCB) composition of extracts of subsurface soil, superficial dust and air from a contaminated landfill

Samples of 3 matrices (air, superficial dust and subsurface soil) from an aged PCB-containing landfill were extracted and the extracts refined for bioassay. Acetone: hexane extraction was modestly selected for non-planar compounds. Coplanar PCBs and PCDFs were enriched about 2-fold in the subsequent benzene:methylene chloride extracts of the soil. Extract refinement with Florisil slurry and alumina column chromatography did not appreciably change the composition of the extracts. CB 28 (2,4,4′-triCB) dominated in all extracts. The congener composition of soil and air were surprisingly similar, being enriched in tri- and tetraCBs while dust retained higher proportions of congeners with 4 and 5 chlorines. It is postulated that anaerobic dechlorination in the moist subsurface soil depleted the higher chlorinated congeners; more volatile congeners escaped into the atmosphere while moderately chlorinated congeners were trapped in the superficial dust and debris. The refined extracts represent distinct compositions of environmental PCB mixtures suitable for bioassay.

Occupational and Environmental Lead and PCB Exposure at a Scrap Metal Dealer

Blood lead levels (BPb) and serum polychlorinated biphenyl levels (PCB) were obtained from 17 employees at two adjacent scrap metal dealers. One facility was located outdoors, directly on top of soil known to be contaminated with lead and PCBs, and the other was located indoors with a concrete floor. BPbs ranged from 4.0 to 39.8 μg/dl (mean 19.9 μg/dl, geometric mean 17.5 μg/dl) and PCB levels ranged from < 1 to 65.3 ppb (mean 7.5 ppb). There was no significant difference in either BPb or serum PCB between the two sites. BPb was significantly correlated with the number of cigarettes smoked at work, and both BPb and serum PCB were significantly related to eating lunch outside the lunchroom, suggesting hand-to-mouth contact as a source of exposure. The lack of difference in BPb between employees of the two scrap metal dealers suggests an ongoing source of lead exposure at the sites, other than the soil.

Qualitative and quantitative determination of PCB congeners by using a HT-5 GC column and an efficient quadrupole MS

The determination of CB congeners by means of a new HT-5 column (SGE Australia) was carried out with a quadrupole GC-MS. A method is presented that permits the qualitative and quantitative determination of environmental and technical PCB mixtures with the help of only 14 single CBs, 2–4 reference CBs per degree of chlorination in SIM mode. More than 70 individual CBs, including some coplanar congeners such as CB-77, CB-126 and CB-169, were measured as pure standards. Additionally Clophen A30/A40/A60 and Aroclor 1254 1260 were measured. With our method a total of 131 single CBs could be identified. For the quantitative determination several PCB congener groups were formed for each level of chlorination according to their fragmentation pattern. One CB with group-typical fragmentation was used as reference for the calibration within the group. The fragmentation pattern is strongly correlated with the molecular structure of the single CB, so that CBs not available as pure standards can be identified. Some remarkable correlations between structure of CBs of all degrees of chlorination and their fragmentation in MS EI-mode were discovered. A similar retention time does not mean a similar fragmentation pattern of these CBs and vice versa. The measurements were carried out in scan mode measuring masses 100–650 and in SIM-mode, considering the [M] +, [MCL] + and [M2Cl] + ions.