Selected PCB Congeners Research Articles

An Optimized and Validated QuEChERS-Based Method for the Determination of PCBs in Edible Aquatic Species

AbstractIn the present research, a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was optimized and validated for the determination of 14 selected PCB congeners in mussel (Mytilus galloprovincialis) and fish samples (Sparus aurata). The optimization included the selection of different QuEChERS procedures, extraction solvent, sample weight, and suitable sorbents for the clean-up step to achieve high sensitivity and minimal matrix interferences simultaneously. The identification and quantification of the selected PCBs were carried out using GC–MS. The method was validated providing in all cases excellent linearity (r2 above 0.99). Recoveries were estimated at three different fortification levels (10, 50, and 100 ng g−1) and ranged from 72.5 to 109.5% and 72.1 to 88.4% for mussel and fish samples, respectively. In addition, for both matrices, the LOQs ranged from 1 to 2.5 ng g−1. The matrix effect was in all cases < 29%, while the expanded uncertainty U%, which was estimated at all the fortification levels, was found below 53% in all cases. Eventually, the optimized and validated method was applied to mussel and fish samples acquired from aquacultures in NW Greece, revealing the absence of the selected congeners in all cases.

Evaluation and Distribution of Selected Polychlorinated Biphenyl Congeners and Triclosan in Soil, Sediment and Surface Water System: A Case Study of Ojutu River, Osun State, Nigeria

ABSTRACT This study evaluated the presence of seven-selected polychlorinated biphenyls and triclosan in the Ojutu River, Osun State Nigeria. The soil, sediment and surface water at five different sampling sites were investigated following the standard analytical procedure. The maximum concentration of targeted PCBs in soil, sediment and water are; 1.02 µg/g, 0.6490 µg/g and 0.02981 µg/mL respectively. While triclosan has 0.0562 ng/g, 0.0457 ng/g and 0.001070 ng/mL in sediment, soil and water samples respectively. The concentrations of some of the selected PCB congeners and triclosan were significant in sediment and soil samples across the sites while the majority analytes showed no significant differences in water samples across the sites. The parameters investigated were found within the WHO maximum permissible limit therefore the water could be considered less susceptible to these pollutants. Other contaminants such as personal care products, pharmaceuticals, heavy metals and micro-pollutants as well as pollution levels associated with microbial load are worthy of investigation to know the actual state of the river for the safety of aquatic lives and the health of humans who depends on this river.

Occurrence of polychlorinated biphenyl congeners in marine sediment of Makran region, Chabahr bay, Iran

In this study, selected PCB congeners (IUPAC numbers 28, 52, 101, 138, 153, and 180) were quantified in 34 stations of Chabahr bay and around it in the Makran region of Iran. The sum of total PCB concentrations varied from below the detection limit to 485 ng kg−1 dry weight of sediment. Based on the Canadian Sediment Quality Guidelines, the effect of detected PCBs was negligible for aquatic organisms. According to the dominance of PCB 28 and 52 with average range of 62 to 100% of total PCBs, maritime transportation and atmospheric deposition appear to be the important source of PCBs in this region. Further, the presence of components of commercial products such as ClophenA50 appears to be one of the probable sources.

Monitoring and Risk Assessment of Selected Pesticide Congeners (PCBs) in Nile River Waters, Egypt

Discharging of higher levels of persistent organic pollutant (POPs) including PCBs to the Nile River waters poses a great environmental impact and human hazardous risk. Therefore, we carried out this study to assess the concentration levels of selected PCB congeners and evaluate their health risk at three different areas along Nile River from South to North of Egypt. Collected samples were extracted and analyzed using (GC-Ms, Agilent). The detected total average concentration levels of selected ten PCB congeners along the three sampling sites Beni-suef (S1), Greater Cairo S2) and Banha (S3) were ranged from 3.89 to 25.5 with an average of 16.51 𝜇g/L, 5.51 to 33.61 with an average of 20.75 𝜇g/L and from 6.14 to with an average of 27.01 𝜇g/L at S1, S2 and S3, respectively. These concentrations were above the acceptable permissible limit set by USEPA for PCBs in drinking water (0.5 𝜇g/L), indicating an important PCB pollution problem in the Nile River water and high possibility of human adverse health effects. Therefore, counter measures and laws enforcement should be applied to minimize the risk of PCBs in the Egyptian environment.

Organochlorine contaminant concentrations in multiple tissues of free-ranging Steller sea lions (Eumetopias jubatus) in Alaska

The relationships of selected organochlorine (OC) contaminants between blubber, blood, feces, and milk of young, free-ranging Steller sea lions (Eumetopias jubatus) were examined. Both between and within each tissue there was considerable individual variation. In spite of the variation, similar patterns were observed across the tissues for most of the selected PCB congeners. In all four tissues, the major PCB congeners were PCB101, PCB118, PCB138, and PCB153. The most prominent congener, both as a weight (ng/g lipid) and as a percentage of summed PCBs (∑PCBs), was PCB 153. Comparisons between paired tissues showed that ∑DDTs in blubber samples were related to concentrations in blood, feces, and milk. The ∑PCBs in blubber were related to concentrations in milk and fecal samples, though the relationship with feces was weak. Our findings show milk samples, in particular, are useful for assessing OCs in young sea lions. Blubber concentrations of PCB101, PCB118, and PCB138 were an order of magnitude higher than those in milk, supporting the biomagnification of these PCB congeners in SSL tissues. The findings indicate alternative tissues may be used as indicators of relative contaminant exposure in lieu of surgical blubber biopsy.

Calculating the Diffusive Flux of Persistent Organic Pollutants between Sediments and the Water Column on the Palos Verdes Shelf Superfund Site Using Polymeric Passive Samplers

Passive samplers were deployed to the seafloor at a marine Superfund site on the Palos Verdes Shelf, California, USA, and used to determine water concentrations of persistent organic pollutants (POPs) in the surface sediments and near-bottom water. A model of Fickian diffusion across a thin water boundary layer at the sediment-water interface was used to calculate flux of contaminants due to molecular diffusion. Concentrations at four stations were used to calculate the flux of DDE, DDD, DDMU, and selected PCB congeners from sediments to the water column. Three passive sampling materials were compared: PE strips, POM strips, and SPME fibers. Performance reference compounds (PRCs) were used with PE and POM to correct for incomplete equilibration, and the resulting POP concentrations, determined by each material, agreed within 1 order of magnitude. SPME fibers, without PRC corrections, produced values that were generally much lower (1 to 2 orders of magnitude) than those measured using PE and POM, indicating that SPME may not have been fully equilibrated with waters being sampled. In addition, diffusive fluxes measured using PE strips at stations outside of a pilot remedial sand cap area were similar to those measured at a station inside the capped area: 240 to 260 ng cm(-2) y(-1) for p,p'-DDE. The largest diffusive fluxes of POPs were calculated at station 8C, the site where the highest sediment concentrations have been measured in the past, 1100 ng cm(-2) y(-1) for p,p'-DDE.

Bioassay-derived dioxin equivalent concentrations in gonads and livers of the Atlantic cod females from the Baltic Sea

The DR-H4IIE.Luc bioassay is based on the ability of dioxin and dioxin-like contaminants to activate the AhR and its signal transduction pathway, a mechanism through which these contaminants elicit their toxic effects. The bioassay was used to examine the total dioxin-equivalent (TEQ) toxicity in gonads and livers of cod females from the southern Baltic Sea. The bioassay-derived TEQ-luc was measured after 24-h and 48-h exposure periods. Mean concentrations in the 24-h bioassay were 95 and 35 pg TEQ-luc g −1 lipid in gonads and livers, respectively, and 58 and 38 pg TEQ-luc g −1 lipid in the 48-h bioassay, respectively. The 48-h TEQ-luc levels displayed significant relationships with ΣPCB 7 and selected PCB congeners but not with the TEQ DLPCB-REP. Levels in gonads approached 10% of the LC50 for developing larvae of other marine fish, yet the impact on survival of the cod during its early life remains to be assessed in a future.

Towards a global historical emission inventory for selected PCB congeners — A mass balance approach

Previously published estimates of the global production, consumption and atmospheric emissions of 22 individual PCB congeners [Breivik K, Sweetman A, Pacyna JM, Jones KC. Towards a global historical emission inventory for selected PCB congeners – a mass balance approach. 1. Global production and consumption. Sci Total Environ 2002a; 290: 181-198.; Breivik K, Sweetman A, Pacyna JM, Jones KC. Towards a global historical emission inventory for selected PCB congeners – a mass balance approach. 2. Emissions. Sci Total Environ 2002b; 290: 181-198.] have provided useful information for later studies attempting to interpret contaminant levels in remote areas as well as in the global environment. As a result of the need for more contemporary emission data (following the year 2000), an update of this emission database is presented. This exercise takes into account new information on PCB production in Poland, as well as new data on the chemical composition of various technical mixtures for which less information had been available. The methodology to estimate temporal trends of PCB emissions associated with various types of PCB usage is improved. Projected emissions up to year 2100 are presented to facilitate predictions of future environmental exposure. The national emission data for each of the 114 countries considered is spatially resolved on a 1° × 1° grid for each congener and year, using population density as a surrogate.

Association Between Environmental Exposure to PCBs and Hearing Impairment in 8- to 9-Year-old Children

SM1-PD-02 Introduction: A chemical plant produced PCBs between 1959 and 1984. Disposal of effluent into a river resulted in contamination of a site sized about 70 by 30 km. It accommodates approximately 250,000 inhabitants and is recognized as one of the most heavily polluted areas with PCBs in the world. The data for sum of PCB serum concentrations for 433 8- to 9-year-old children living in this area in 2002 were: mean 528.2 ng/g of serum lipids, median 321 ng/g of serum lipids and limits of the quartiles 18, 175, 321, 618, 6477 all in ng/g of serum lipids. It was reported that auditory thresholds for 1-kHz tones were elevated by approximately 25 dB in animals exposed to PCB.1 They were linked to a loss of outer hair cells.2 Therefore, hearing examination was included into our study program. Methods: The concentrations of selected PCB congeners in serum of 8- and 9-year-old children were determined using GC/ECD. Hearing examination involved pure tone audiometry (Madsen Orbiter 922), transient evoked otoacoustic emissions (Otodynamics ILO 88), auditory brainstem response (Otometrics BERA System), and tympanometry (Siemens SD-30 tympanometer). Results: The main findings are as follows: An association between negative middle ear pressure and PCB serum concentrations. Increase of the hearing thresholds at low frequencies associated with higher PCB serum concentrations. No association between the serum PCB concentrations and any of the auditory brainstem response parameters. Higher serum PCB concentrations associated with decreased emission levels of the transient evoked otoacoustic emissions. The sound pressure level of otoacoustic emissions was associated with results of several neurobehavioral tests applied in the same cohort of children and with the proportion of the permanent teeth with demarcated and diffuse opacities or hypoplasia. Discussion and Conclusions: The data of Longnecker et al3 did not support adverse effects of PCBs during early life on sensorineural hearing loss. The exposure levels were twofold higher than recent background levels in the United States. In contrast to the previous data at our much higher exposure levels, subclinical but significant increase of hearing thresholds and a decrease of sound pressure level of transient evoked otoacoustic emissions were associated wth PCBs serum concentrations. A follow-up study on the same cohort will bring additional information on related time trends.

Coplanar and non-coplanar congener-specificity of PCB bioaccumulation and immunotoxicity in sea stars

The sea star Asterias rubens (L.), a representative species of the North Sea benthic environment, was exposed to a mixture of 10 selected PCB congeners (3 coplanar or c-PCBs, and 7 non-coplanar) via experimentally contaminated sediments. Both the degree of bioaccumulation and subsequent immunotoxic effects of these PCBs were determined. A strong congener-specificity for both bioaccumulation and immunotoxicity was found as well as a probable induction of a congener-specific detoxification mechanism resulting in the dramatic decrease in body levels of the three coplanar congeners tested (PCBs 77, 126 and 169). Moreover, a correlation was found between the bioaccumulation of c-PCBs and their immunotoxic effects. These findings suggest that coplanar congeners should be included in the list of congeners recommended to be analyzed for biological impact-oriented marine monitoring programmes.

The maximum reservoir capacity of soils for persistent organic pollutants: implications for global cycling

The concept of maximum reservoir capacity (MRC), the ratio of the capacities of the surface soil and of the atmospheric mixed layer (AML) to hold chemical under equilibrium conditions, is applied to selected persistent organic pollutants (POPs) in the surface ‘skin’ (1 mm) of soils. MRC is calculated as a function of soil organic matter (SOM) content and temperature-dependent K OA and mapped globally for selected PCB congeners (PCB-28; -153; -180) and HCB, to identify regions with a higher tendency to retain POPs. It is shown to vary over many orders of magnitude, between compounds, locations and time (seasonally/diurnally). The MRC approach emphasises the very large capacity of soils as a storage compartment for POPs. The theoretical MRC concept is compared to reality and its implications for the global cycling of POPs are discussed. Sharp gradients in soil MRC can exist in mountainous areas and between the land and ocean. Exchanges between oceans and land masses via the atmosphere is likely to be an important driver to the global cycling of these compounds, and net ocean–land transfers could occur in some areas.

Distribution of organochlorine pesticides, polychlorinated biphenyls and α-HCH enantiomers in pork tissues

The distribution of HCH isomers, DDT analogues and selected PCB congeners in pork organs collected from the same individuals raised in Romanian farms was investigated. Organochlorine pesticides (HCHs and DDTs) were the principal contaminants in all samples, while PCB concentrations were low, in accordance with previously reported concentrations from Romanian animal farms. The most part of the pollutant load in the body is retained in the adipose tissue, with HCHs ranging between 16 and 27.7 ng/g lipid and with higher concentrations of DDTs ranging between 65.9 and 334.5 ng/g lipid. The highest PCB levels (up to 32 ng/g lipid) were measured in lung and liver. The lipid-normalized concentrations in the brain were lower than in all other tissues due to the presence of the blood-brain barrier or due to a lower proportion of the neutral lipids such as triglycerides. The highest concentrations of DDTs were measured in muscle and fat, with p, p ′-DDE being the principal contributor and with a variable contribution of p, p ′-DDD and p, p ′-DDT. In liver, p, p ′-DDD has a higher contribution to the sum DDTs, while in all analyzed livers, the concentration of p, p ′-DDT was very low. β-HCH was the most persistent HCH isomer in all tissues, accounting for 40–97% of sum HCHs. For all animals, the highest concentrations of β-HCH and HCHs were found in liver, while the lowest HCH concentrations were measured in brain and spinal marrow. Additionally, the distribution of α-HCH enantiomers in the tissues was discussed. In all samples (except 2 brain samples), (+) α-HCH was depleted and (−) α-HCH was enantioenriched. Enantiomeric ratios in brain were the highest measured values between all organs. For all studied animals, ERs increased in the order fat < muscle < liver < brain.

PCB in soils and estimated soil–air exchange fluxes of selected PCB congeners in the south of Sweden

PCB concentrations were studied in different soils to determine the spatial variation over a region of approximately 11 000 km 2. PCB congener pattern was used to illustrate the spatial differences, as shown by principal component analysis (PCA). The relationship to different soil parameters was studied. PCB concentrations in soil showed a large variation between sampling-areas with median concentrations ranging between 2.3 and 332 ng g −1 (dw). Highest concentrations were found at two sites with sandy soils, one with extremely high organic carbon content. Both sites were located on the west coast of southern Sweden. Soils with similar soil textures (i.e. sandy silt moraine) did not show any significant differences in PCB concentrations. PCB congener composition was shown to differ between sites, with congener patterns almost site-specific. PCB in air and precipitation was measured and the transfer of chemicals between the soil and air compartments was estimated. Soil–air fugacity quotient calculations showed that the PCBs in the soil consistently had a higher fugacity than the PCBs in the air, with a median quotient value of 2.7. The gaseous fluxes between soil and air were estimated using standard modelling equations and a net soil–air flux estimated by subtracting bulk deposition from gaseous soil–air fluxes. It was shown that inclusion of vertical sorbed phase transport of PCBs in the soil had a large effect on the direction of the net soil–air exchange fluxes.

PCB congener distribution in estuarine water, sediment and fish samples: implications for monitoring programs.

Traditional analyses for PCBs in environmental matrices have focused on commercial Aroclor mixtures with detection limits in the 100 to 1000 part per trillion range. This approach has recently been supplanted by analyses for specific PCB compounds called congeners with detection limits less than 0.5 ppt. At the national level, total PCB determinations based upon selected PCB congeners typically characterize analyses of surface water, sediment and tissue. These federal efforts rely on a suite of 18 to 20 congeners out of a total of 209 congeners to characterize total PCB. The present study compares total PCB estimates based upon this subset of congeners with estimates based upon an expanded list of 81 congeners from water, sediment and fish tissue collected from the Delaware Estuary. Analytical data from monitoring programs conducted in the Delaware Estuary by the Delaware River Basin Commission, NOAA National Ocean Service, U.S. Army Corps of Engineers and the U.S. Environmental Protection Agency from 1996 to 1998 were evaluated. Total PCB estimates derived from the different sets of congeners, including the adjustment factor of 2.0 used by NOAA, were compared. This evaluation indicated that differences exist between total PCB determinations based upon these approaches, and that these differences vary depending on the matrix analyzed. The bias associated with using a smaller set of PCB congeners, and the implications for risk assessment are discussed.

Storage of sediment-associated nutrients and contaminants in river channel and floodplain systems

Samples of fine-grained channel bed sediment and overbank floodplain deposits were collected along the main channels of the Rivers Aire (and its main tributary, the River Calder) and Swale, in Yorkshire, UK, in order to investigate downstream changes in the storage and deposition of heavy metals (Cr, Cu, Pb, Zn), total P and the sum of selected PCB congeners, and to estimate the total storage of these contaminants within the main channels and floodplains of these river systems. Downstream trends in the contaminant content of the <63 μm fraction of channel bed and floodplain sediment in the study rivers are controlled mainly by the location of the main sources of the contaminants, which varies between rivers. In the Rivers Aire and Calder, the contaminant content of the <63 μm fraction of channel bed and floodplain sediment generally increases in a downstream direction, reflecting the location of the main urban and industrialized areas in the middle and lower parts of the basin. In the River Swale, the concentrations of most of the contaminants examined are approximately constant along the length of the river, due to the relatively unpolluted nature of this river. However, the Pb and Zn content of fine channel bed sediment decreases downstream, due to the location of historic metal mines in the headwaters of this river, and the effect of downstream dilution with uncontaminated sediment. The magnitude and spatial variation of contaminant storage and deposition on channel beds and floodplains are also controlled by the amount of <63 μm sediment stored on the channel bed and deposited on the floodplain during overbank events. Consequently, contaminant deposition and storage are strongly influenced by the surface area of the floodplain and channel bed. Contaminant storage on the channel beds of the study rivers is, therefore, generally greatest in the middle and lower reaches of the rivers, since channel width increases downstream. Comparisons of the estimates of total storage of specific contaminants on the channel beds of the main channel systems of the study rivers with the annual contaminant flux at the catchment outlets indicate that channel storage represents <3% of the outlet flux and is, therefore, of limited importance in regulating that flux. Similar comparisons between the annual deposition flux of specific contaminants to the floodplains of the study rivers and the annual contaminant flux at the catchment outlet, emphasise the potential importance of floodplain deposition as a conveyance loss. In the case of the River Aire the floodplain deposition flux is equivalent to between ca. 2% (PCBs) and 36% (Pb) of the outlet flux. With the exception of PCBs, for which the value is ≌0, the equivalent values for the River Swale range between 18% (P) and 95% (Pb). The study emphasises that knowledge of the fine-grained sediment delivery system operating in a river basin is an essential prerequisite for understanding the transport and storage of sediment-associated contaminants in river systems and that conveyance losses associated with floodplain deposition exert an important control on downstream contaminant fluxes and the fate of such contaminants.

Towards a global historical emission inventory for selected PCB congeners — a mass balance approach: 2. Emissions

Accurate and complete data on the global atmospheric releases ( emissions) of individual PCB congeners are essential to study source–receptor relationships and contamination patterns in remote areas, such as the Arctic. Information on the anthropogenic emissions may also be useful for the interpretation of measured levels and patterns of atmospheric PCBs. This study builds upon an accompanying paper, presenting an estimate of the global historical production and consumption of 22 PCB congeners (Breivik K, Sweetman A, Pacyna JM, Jones KC. Towards a global historical emission inventory for selected PCB congeners — a mass balance approach. 1. Global production and consumption. Sci Total Environ, submitted). Here, a dynamic mass balance model is elaborated, parameterised and applied in an attempt to estimate the historical anthropogenic emissions as a direct result of the widespread usage of PCBs for a period of 70 years. This paper presents details of the mass balance approach, along with a discussion of the major uncertainties. It is shown that the diversity of historical usage, disposal and accidental release pathways makes it an extremely difficult task to bridge the gap between consumption and emissions, resulting in an equally complex and diverse true emission pattern. These results may therefore at best represent order-of-magnitude estimates only and the results in absolute terms should be treated with great caution. In spite of these uncertainties, useful information can still be gained. The results suggest that temperature is an extremely important factor controlling both emission amount as well as the emission pattern of PCBs. In particular, the emissions of the more chlorinated (and persistent) PCB congeners appear to be significantly influenced by (uncontrolled) high-temperature sources. As a consequence, it may prove warranted to undertake further measures to avoid that contaminated materials are subject to elevated temperatures and uncontrolled burning. It is furthermore suggested that efforts should be directed towards a better characterisation and quantification of these potentially important release pathways. In addition, alternative approaches to bridge the gap between consumption and emissions in quantitative terms should be considered in order to improve these estimates.

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.

PCDDS, PCDFS, PCBS and HCB in marine and estuarine sediments from Queensland, Australia

Concentrations of 2,3,7,8-chlorine substituted PCDDS, PCDFs, selected PCB congeners and HCB were determined in sediment samples collected from sites along the east coast of Queensland in northern Australia. PCDDS were detectable in all sediment samples while PCDFs, PCBs and HCB were mainly found in sediment samples collected from sites in the Brisbane metropolitan area. The results provide evidence that an unidentified source for higher chlorinated PCDDS exists along the Queensland coast.

Comparison of PCB and DDT Distribution between Water-column and Sediment-dwelling Bivalves in Arcachon Bay, France

Selected PCB congeners and DDT and its degradation products were analysed in various bivalves and sediment from Arcachon Bay, France. The distribution of these compounds is compared between the different species of bivalve. The two classes of bivalve, water column and sediment dwelling can be distinguished by their concentrations and distributions of organic contaminants. Normalisation of concentration to total lipid content reduces the variability of the PCB concentrations, but no correlation is found between organic contaminant concentration and lipid content.

Development of an analytical method for the determination of congener specific PCBs in selected polymeric packaging materials.

at least 18 and perhaps up to 36 of the 209 congeners have potential for toxicity due to their abundance in fish/animal tissue and their demonstrated enzyme induction effects (McFarland & Clark 1989, Tanabe 1988). Recent research has focused on the use of polymeric materials as cleanup and bioconcentration tools and for the analysis of PCBs and other organic chemicals from water, soil and lipophilic media (Huckins et al. 1990, Zabik et al. 1992). In food packaging, there is a need for research on issues such as the migration of PCBs from packaging materials to packaged foods or the reverse case, the sorption of PCBs from contaminated foods by the packaging material. The purpose of this study was to develop the methodology for the determination of specific PCB congeners in selected polymeric packaging materials used for the packaging of foods. Once the method is developed, it will be possible to investigate the effect of the chemical composition and physical characteristics of food polymers on the potential sorption of selected PCB congeners ranging from tri to deca chlorinated PCBs.