Polychlorinated naphthalenes: an environmental update

Human exposure to polychlorinated naphthalenes and polychlorinated diphenyl ethers from foods in Catalonia, Spain: temporal trend

Although polychlorinated naphthalenes (PCNs) and polychlorinated diphenyl ethers (PCDEs) are pollutants that have been detected in a number of environmental samples, information concerning human exposure to these compounds through the diet is very scarce. In this study, the concentrations of PCNs and PCDEs were determined in samples of foodstuffs widely consumed by the population of Catalonia, Spain. The dietary intake of PCNs and PCDEs also was estimated for the population of this Spanish region, and the results were compared to those of a previous survey performed during 2000. The highest sigmaPCNs corresponded to fish and seafood (47.1 ng/kg wet wt), followed by oils and fats (21.5 ng/kg wet wt), bakery products (15.3 ng/kg wet wt), and dairy products (11.7 ng/ kg wet wt). The highest sigmaPCDEs corresponded also to fish and seafood (1094.7 ng/kg wet wt), a value that was notably higher than those concerning the remaining food groups. For a standard male adult of 70 kg body weight, the dietary intakes of PCNs and PCDEs were 7.25 and 51.68 ng/day, respectively (or 0.10 and 0.74 ng/kg body wt/day). These results mean a reduction of 84% for PCNs with respect to the daily intake of these pollutants in the 2000 survey, mainly due to the decreases in the contribution of cereals and oils and fats. By contrast, the intake of PCDEs increased to 26%, fish and seafood being the main contributors to this increase.

Occurrence and profiles of chlorinated and brominated polycyclic aromatic hydrocarbons in waste incinerators

Chlorinated polycyclic aromatic hydrocarbons (CIPAHs) have been reported to occur in urban air. Nevertheless, sources of CIPAHs in urban air have not been studied, due to the lack of appropriate analytical methods and standards. In this study, we measured concentrations of 20 CIPAHs and 11 brominated PAHs (BrPAHs) in fly ash and bottom ash from 11 municipal/hazardous/industrial waste incinerators, using analytical standards synthesized in our laboratory. Concentrations of total CIPAHs and BrPAHs in ash samples ranged from <0.06 to 6990 ng/g and from <0.14 to 1235 ng/g, respectively. The concentrations of CIPAHs were approximately 100-fold higher than the concentrations of BrPAHs. 6-CIBaP and 1-CIPyr were the dominant compounds in fly ash samples. The profiles of halogenated PAHs were similar to the profiles reported previously for urban air. 1-BrPyr was the predominant BrPAH in fly ash. Concentrations of 6-CIBaP, 9,10-Cl2Phe, 9-CIAnt, and 6-BrBaP in fly ash were significantly correlated with the corresponding parent PAH concentrations. Significant correlation between sigmaCIPAH and sigmaPAH concentrations suggests that direct chlorination of parent PAHs is the mechanism of formation of CIPAHs during incineration of wastes; nevertheless, a comparable correlation was not found for BrPAHs. There was no significant correlation between the capacity and temperature of an incinerator and the concentrations of sigmaCl-/BrPAHs in ash samples, although lower concentrations of all halogenated PAHs were found in stoker-type incinerators than in fixed grate-type incinerators. Toxicity equivalency quotients (TEQs) for CIPAHs in ash samples were calculated with CIPAH potencies. Average TEQ concentrations of CIPAHs in fly ash and bottom ash were15800 pg-TEQ/g and 67 pg-TEQ/g, respectively. Our results suggest that the extent of dioxin-like toxicity contributed by CIPAHs in ash generated during waste incineration is similar to that reported previously for dioxins. Waste incineration is an important source of Cl-/BrPAHs in the urban atmosphere.

Occurrence and biomagnification of polychlorinated naphthalenes and non- and mono-ortho PCBs in Lake Ontario sediment and biota

Biota and surface sediments collected from Lake Ontario were analyzed for polychlorinated naphthalenes (PCNs) and non- and mono-ortho-substituted polychlorinated biphenyls (n/ m-o-PCBs) to compare bioaccumulation behavior of these classes of dioxin-like chemicals in a food web from the Great Lakes. Mean sigmaPCN concentrations (tri-octaCN) ranged from 14 +/- 9 pg/g in plankton to 3500 +/- 3200 pg/g (wet weight) in lake trout while sediments contained from 21 to 38 ng/g (dry weight). Principal components analysis of PCN congener patterns indicated that chlorine substitution determined which congeners favored accumulation (e.g., CN-42, -52, -60, -66, -67, and -73), while others may be subject to metabolism. The bioaccumulative congeners exhibited similar trophic magnification factors (TMFs; 1.23-1.42) and biomagnification factors (BMFs; 5.5-8.6) to the n/m-o-PCBs for the trout/weighted diet relation, although BMFs for a benthic feeding relationship (slimy sculpin/Diporeia) indicated that the n/m-o-PCBs were more bioavailablethroughthe benthic pathway. PCNs contribute significantly to the burden of dioxin-like compounds in Lake Ontario biota, contributing between 12 and 22% of total PCN + PCB TEQ in lake trout and up to 69% in benthic organisms.

Occurrence of polychlorinated naphthalenes, polychlorinated biphenyls and short-chain chlorinated paraffins in marine sediments from Barcelona (Spain)

Polychlorinated naphthalenes (PCNs), short-chain chlorinated paraffins (SCCPs) and polychlorinated biphenyls (PCBs) were analysed in marine sediment samples collected from the coastal area of Barcelona (Spain) and near of a submarine emissary coming from a waste water treatment plant located at the mouth of the Besòs River (Barcelona). An integrated sample treatment based on Soxhlet extraction followed by a simple clean-up with Florisil and graphitized carbon cartridge was employed. Gas chromatography coupled to ion-trap tandem mass spectrometry (GC-MS/MS) and gas chromatography-mass spectrometry in electron capture negative ionization mode, were used for PCN and SCCP determinations, respectively, while for PCB analysis gas chromatography with electron capture detection (GC-ECD) was used. The method developed provided low limits of detection (0.001-0.003 ng g(-1) dry weight (dw) for PCNs, 1.8 ng g(-1) for SCCPs and 0.006-0.014 ng g(-1)dw for PCBs) and good run-to-run precisions (lower than RSD 8%) for the analysis of sediment samples. Concentration levels ranging from 0.17 to 3.27 ng g(-1)dw for PCNs, between 0.21 and 1.17 microg g(-1)dw for SCCPs, and from 2.33 to 44.00 ng g(-1) (dw) for PCBs, were found in the coastal sediments, while for samples collected near to the submarine emissary higher levels (from 2.02 to 6.56 ng g(-1)dw for PCNs, between 1.25 and 2.09 microg g(-1)dw for SCCPs and from 22.34 to 37.74 ng g(-1)dw for PCBs) were obtained. The results obtained provide new data about the occurrence of PCN and SCCP in the coastal area of Barcelona.

The teratogenic effects of polychlorinated naphthalenes (PCNs) on early development of the zebrafish (Danio rerio)

The present study examines the effects of PCN congeners (PCN50 and PCN66) on zebrafish embryos. The embryos were exposed to different concentrations (20, 30 and 50μg/l) of the respective congeners by dissolving 0.08% acetone. The following endpoints were investigated (mortality, hatching rate, abnormalities and heart rate). No effect on survival was recorded for 20μg/l PCN congeners. On the other hand, embryos exposed to 30 and 50μg/l PCNs showed a significant reduction in survival rate. No developmental defects occurred with any of the congeners at the 20μg/l concentration. However, starting with 30μg/l, weak to very pronounced abnormalities (Lordosis, Kyphosis, disrupted axial body, tail defect, reduced heartbeat, and abnormal hatching) were observed depending on the congener and the concentration used. PCN66 has been shown to be more embryotoxic congener than PCN50. This demonstration of zebrafish responsiveness to PCNs early life stage toxicity coupled with the considerable information on developmental biology and genetics of zebrafish provides a foundation for future investigations into the mechanism of PCNs developmental toxicity.

Comprehensive two-dimensional GC (GCxGC) qMS analysis of tetrachloronaphthalenes in Halowax formulations

A combination of non-polar and shape selective columns in a comprehensive two-dimensional GC (GCxGC) system consisting of DB-5MS and LC-50 as the 1st and 2nd dimension columns was used to separate 22 tetrachloronaphthalene isomers. These columns enabled separation of all possible isomers of tetraCN found in the technical chloronaphthalene Halowax formulations into 18 peaks covering 15 single separated isomers and 7 co-eluting in triplicate (1,2,4,6-/1,2,4,7-/1,2,5,7-tetraCN; nos. 33/34/37) and in pairs (1,2,3,7-/1,2,4,5-tetraCN; nos. 30/32 as well as 1,3,5,8-/1,3,6,8-tetraCN; nos. 43/45). Twelve isomers of tetraCN resolved as single compounds by the GC x GC system used were found in Halowax 1001, 1013, 1014 and 1099 as well as in Equi-Halowax mixture. Three other tetraCNs that could be also resolved as single compounds were not detected in these materials, while the remaining 7 tetraCNs, which co-eluted, waits a further separation. The majority of constituents of the tetraCN homologue group of the Halowax formulations are isomers such as 1,4,5,8- (no. 46), 1,2,5,8- (no. 38), 1,2,4,8-tetraCN (no. 35), co-eluting 1,3,5,8-tetraCN (no. 43 in a pair nos. 43/45) and also co-eluting 1,2,4,6-/1,2,4,7-/1,2,5,7-tetraCN (nos. 33/34/37). The less abundant by amongst of tetraCNs in these mixtures are 1,4,6,7- (no. 47) and 1,3,5,7-tetraCN (no. 42). The remaining seven isomers, i.e., 1,2,3,4- (no. 27), 1,2,3,5- (no. 28), 1,2,3,6- (no. 29), 1,2,5,6- (no. 36), 1,2,6,7- (no. 39), 1,2,6,8- (no. 40) and 1,2,7,8-tetraCN (no. 41) are usually minor by quantity, while 1,2,3,7-/1,2,4,5-tetraCN (nos. 30/32) are also minor, or one of them is absent. Three tetraCNs not found in the Halowax formulations are isomers such as 1,2,3,8-tetraCN (no. 31), 1,3,6,7-tetraCN (no. 44) and 2,3,6,7-tetraCN (no. 48).

Health risk assessment for polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans, and polychlorinated naphthalenes in seafood from Guangzhou and Zhoushan, China

This study determined the concentrations of organochlorine contaminants in common seafood in two Chinese coastal cities (Guangzhou and Zhoushan), and assessed the health risk due to the daily consumption of contaminated seafood. Twenty-six pooled samples, belonging to five food categories (fish, bivalves, shrimp, crab, and cephalopods), were purchased from local markets in Guangzhou and Zhoushan in 2003 and 2004. These samples were analyzed for total polychlorinated biphenyls (PCBs), non- and mono-ortho-PCBs (coplanar PCBs), polychlorinated naphthalenes (PCNs), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs). The concentrations of total PCBs and coplanar PCBs in fish samples were higher in Guangzhou than in Zhoushan, while the levels of PCNs and PCDDs/DFs were comparable between the two cities. The total daily intake values of dioxin-like compounds were 1.05 and 0.86pg WHO-TEQ/kg body weight in Guangzhou and Zhoushan, respectively. Hazard ratios of non-cancer risk in the two cities were all less than unity.

Application and comparison of different chemometric approaches in QSPR modelling of supercooled liquid vapour pressures for chloronaphthalenes

Molecular descriptors from calculations at the level of Density Functional Theory (B3LYP/6-311++G**) were effectively applied in QSPR estimation of supercooled liquid vapour pressures (P(L)) for individual chloronaphthalene congeners. The estimated values of log P(L) varied from 1.05 Pa to 5.6 x 10(-5) Pa, depending on the number of chlorine substituents present in the molecule and the substitution pattern. Comparison of the five chemometrical methods of modelling (approaches) led to the final conclusion, that the use of relatively simple PLS combined with one of the variable pre-selection algorithms (UVE or GA) seems to be the optimal choice in such computational studies for persistent organic pollutants. The best GA-PLS model was characterized by the value of root mean square error of prediction RMSEP = 0.108 logarithmic Pascal units.

Polychlorinated naphthalenes and coplanar polychlorinated biphenyls in tissues of harbor seals (Phoca vitulina) from the northern Gulf of Alaska

Blubber, liver and kidney samples of harbor seals (Phoca vitulina) from the northern Gulf of Alaska were collected during 2000-2001 for the analysis of polychlorinated naphthalenes (PCNs) and coplanar polychlorinated biphenyls (CoplPCBs). On the lipid weight (lw) base, the total concentrations of PCNs (Sigma PCNs) ranged from 0.3 to 27 ng/g lw, and the total concentrations of CoplPCBs (Sigma CoplPCBs) were 3.6-546 ng/g lw in all the tissue samples. Di-ortho PCBs and mono-ortho PCBs were dominant followed by non-ortho PCBs and PCNs. Sigma Mono-ortho PCBs and Sigma di-ortho PCBs in nursing seals were apparently lower than those in male adult seals, but Sigma PCNs and Sigma non-ortho PCBs in female adults were not significantly different from those in male adults. Differences in PCNs and CoplPCBs congener profiles in female and male adult seals are apparently related to their chemical structure and properties, animal's developmental stages and physiological conditions. A large quantity of mono-ortho and di-ortho PCBs might be transferred to newborns from the nursing seals during lactation, while non-ortho PCBs and PCNs were relatively accumulative in the mother seals. Sigma PCNs and Sigma CoplPCBs in the harbor seals correlated with ages, gender, body weight and blubber thickness, but the blubber Sigma PCNs and Sigma CoplPCBs in Kodiak Island and Southern Alaska Peninsula (KIAP) did not significantly differ from those in Prince William Sound (PWS). In addition to the new PCB data, this first report on PCN contamination in Alaskan harbor seal tissues is useful for the wildlife and ecosystem management and human health protection.

Polychlorinated naphthalenes in the Global Atmospheric Passive sampling (GAPS) study

Air concentrations of polychlorinated naphthalenes (PCNs) were measured as part of the Global Atmospheric Passive Sampling (GAPS) study to assess their spatial distribution on a worldwide basis for the first sampling period between December 2004 and March 2005. Results from more than 40 sites on seven continents show that PCNs are widespread, and highest levels are detected in urban/industrial locations consistent with other air sampling studies. The geometric mean air concentration of sigmaPCN is 1.6 pg/m3, ranging from below detection limit to 32 pg/m3. With technical PCN mixtures largely no longer produced, combustion inputs may be contributing increasingly to contemporary PCN air burden globally. Enrichment of combustion-related congeners, e.g., PCN-52/60, -50, -51,-54, and -66/67, is observed in the congeneric compositions of air at nearly all sites compared to relatively minor contribution of these congeners in technical PCN formulations. Further evidence of current combustion sources influencing global PCN levels is a higher relative abundance of combustion-related congeners quantified by sigmaPCNcombustion/sigmaPCN. The relative contribution by combustion sources and emissions from technical PCN mixtures is expected to vary among sites since it depends on the combustion sources and the technical mixture used in a particular country or region.

Quantitative structure-activity relationships for the prediction of relative in vitro potencies (REPs) for chloronaphthalenes

Chloronaphthalenes (CNs), due to their structural similarities to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the other "dioxin-like" compounds, can bind to the aryl hydrocarbon receptor (AhR) and induce a wide range of pleotrophic effects. Relative potency of individual dioxin analogues can be measured relative to that of TCDD. Relative effects potencies (REP) can be based on many responses, including in vivo and in vitro responses. Both in vivo and in vitro tests, based on either indigenous responses such as the induction of ethoxyresorufin O-deethylase (EROD) or exogenous reporter genes under the control of the AhR such as luciferase can be used to determine REP values. Here we used measured REP values determined for CNs in two assays. Both assays are based on H4IIE rat hepatoma cells. The H4IIE assay is based on expression of the endogenous reporter gene (CYP-1 A) that codes for the expression of EROD and the H4IIE-luc assay which is based on the exogenous reporter gene (luciferase) transfected into the H4IIE cell line. Experimentally determined REP were available for only 17 and 18 of the 75 possible choronaphthalene congeners, for the H4IIE and H4IIE-luc assays, respectively. For this reason computational models were developed to allow prediction of the relative potencies of the other CN congeners. Predictive relationships were based on quantum chemical descriptors obtained from Density Functional Theory (DFT) calculations (B3LYP/6-311++G**). The final models were found by means of a hybrid method combining a genetic algorithm and artificial neural networks. REP values estimated for individual CNs based on the H4IIE assay ranged from 4.3 x 10(- 9) to 3.2 x 10(- 2) while those based on the H4IIE-luc assay ranged from 4.0 x 10(- 8) to 1.8 x 10(- 3). CN congeners nos. 66, 67, 70 and 73 were exhibited the greatest REP values in both assays. The 1,2,3,5,6,8-hexaCN congener (no. 68) had a REP value that was 10-fold less. The remaining congeners had REP values that were less or did not cause sufficient up-regulation of the monitored genes to allow for the calculation of a REP. Interactions of CNs with the AhR could be affected by three possible factors: molecular size, steric interactions and electrostatic interactions. These findings are discussed relative to the use of consensus TCDD equivalency factors' (TEFs) for use in risk assessments of CNs for regulatory purposes.

Polychlorinated biphenyls and -naphthalenes in pine needles and soil from Poland--concentrations and patterns in view of long-term environmental monitoring

Pine needles were selected as cost effective and easy collectable matrices suitable for long-term monitoring of the lower troposphere pollution with polychlorinated biphenyls and polychlorinated naphthalenes. The fingerprints of PCNs and PCBs in the top layers of agricultural soils were used for determination of point sources of pollution for terrestrial ecosystems. The new idea based on the use of nona- and decachlorinated isomers fingerprint as an additional tool suitable for the identification of potential point sources of pollution with PCBs, seemed to be a capable tool to identify contamination of soil and ambient air related to former manufacturing and the use of highly chlorinated technical PCB preparations.

QSPRs on photodegradation half-lives of atmospheric chlorinated polycyclic aromatic hydrocarbons associated with particulates

A quantitative structure-property relationship (QSPR) model which could predict photodegradation half-lives (t(1/2)) of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) associated with particulates in the atmosphere was developed by applying quantum chemical parameters computed with quantum chemical PM3 algorithm and using a partial least squares (PLS) algorithm. The cross-validated Q(2)(cum) value for the optimal QSPR model is 0.960, indicating a good predictive capability for logt(1/2) values of ClPAHs. The QSPR results show that the main factors affecting logt(1/2) values of ClPAHs are the energy of the second highest occupied molecular orbital (E(LUMO-1)), the energy of the second highest occupied molecular orbital (E(HOMO+1)), average molecular polarizability (alpha), the most positive net atomic charges on a hydrogen atom (Q(H)(+)), E(LUMO)+E(HOMO), E(LUMO)-E(HOMO), and (E(LUMO)-E(HOMO))(2). ClPAHs with high E(LUMO-1), E(HOMO+1), E(LUMO)-E(HOMO,) and (E(LUMO)-E(HOMO))(2) values tend to photolyze slowly in the atmosphere. In contrast, increasing E(LUMO)+E(HOMO), alpha, and Q(H)(+) values leads to the increase of photodegradation rates.

PCBs, PCNs and PBDEs in sediments and mussels from Qingdao coastal sea in the frame of current circulations and influence of sewage sludge

Influence of current circulation and sewage sludge on spatial distributions of polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polybrominated diphenyl ethers (PBDEs) in sediments and mussels from the Qingdao coastal sea were investigated. Total concentrations of PCBs, PCNs and PBDEs in sediments ranged 6.5-32.9, 0.2-1.2, and 0.1-5.5 ngg(-1) dry wt, respectively. The maximum concentrations were all found near the Haibo River mouth, affected by sewage sludge input from the river. Under the current system in Jiaozhou Bay the organic pollutants were subject to deposit on the east side of the bay and trapped inside the bay. Sewage sludge was an important source of PCBs, PCNs and PBDEs in the bay and exponentially magnified the enrichment of PCBs. On the other hand, the congener profiles of PCBs in sediments outside the bay may signify an atmospheric source of PCBs. Total Concentrations of PCBs, PCNs and PBDEs in mussels were 61.4-88.6, 9.0, and 13.8 ngg(-1)lipid, respectively. Mussels enriched significantly PCBs, PCNs and PBDEs relative to the sediments. The total toxicity equivalent quantities (TEQs) of PCNs in mussels were generally lower than that of PCBs. The fluxes of the total PCBs and their TEQs have been decreased steadily since 1950s. The lower chlorinated/brominated congeners of PCNs and PBDEs may exhibit a greater tendency due to less lipophilic and thus a greater probability of being affected by the current circulation in the bay.

Human exposure to polychlorinated naphthalenes through the consumption of edible marine species

The concentrations of polychlorinated naphthalenes (PCNs) were determined in samples of 14 edible marine species (sardine, tuna, anchovy, mackerel, swordfish, salmon, hake, red mullet, sole, cuttlefish, squid, clam, mussel and shrimp), which are widely consumed by the population of Catalonia, Spain. The daily intake of PCNs associated with this consumption was also determined. A total of 42 composite samples were analyzed by HRGC/HRMS. The highest PCN levels (ng/kg of fresh weight) were found in salmon (227) followed by mackerel (95) and red mullet (68), while the lowest levels of total PCNs corresponded to shrimp (4.9) and cuttlefish (2.7). With the exception of cephalopods and shellfish species, in which tetra-CN was the predominant homologue, penta-CN (60%) was the predominant contributor to total PCNs. For a standard male adult, PCN intake through the consumption of edible marine species was 1.53 ng/day. The highest contributions to this intake (ng/day) corresponded to salmon (0.41), sole (0.28) and tuna (0.24). Concerning health risks, species-specific TEFs such as those reported by WHO and NATO for PCDD/Fs and dioxin-like PCBs are not currently available for PCN congeners. Although in general terms the results of the present study do not seem to suggest specific risks derived from exposure to PCNs through fish and seafood consumption, to establish the contribution of individual PCN congeners to total TEQ is clearly necessary for the assessment of human health risks.

Advances in the environmental analysis of polychlorinated naphthalenes and toxaphene

Recent advances in the analysis of the chlorinated environmental pollutants polychlorinated naphthalenes (PCNs) and toxaphene are highlighted in this review. Method improvements have been realized for PCNs over the past decade in isomer-specific quantification, peak resolution, and the availability of mass-labeled standards. Toxaphene method advancements include the application of new capillary gas chromatographic (GC) stationary phases, mass spectrometry (MS), especially ion trap MS, and the availability of Standard Reference Materials that are value-assigned for total toxaphene and selected congener concentrations. An area of promise for the separation of complex mixtures such as PCNs and toxaphene is the development of multidimensional GC techniques. The need for continued advancements and efficiencies in the analysis of contaminants such as PCNs and toxaphene remains as monitoring requirements for these compound classes are established under international agreements.

Polychlorinated naphthalenes in Great lakes air: assessing spatial trends and combustion inputs using PUF disk passive air samplers

Passive air samplers made from polyurethane foam (PUF) disks housed in stainless steel chambers were deployed over four seasons during 2002-2003, at 15 sites in the Laurentian Great lakes, to assess spatial and temporal trends of polychlorinated naphthalenes (PCNs). Sampling rates, determined using depuration compounds pre-spiked into the PUF disk prior to exposure, were, on average, 2.9 +/- 1.1 m3 d(-1), consistent with previous studies employing these samplers. PCN air concentrations exhibited strong urban-rural differences-typically a few pg m(-3) at rural sites and an order of magnitude higher at urban sites (Toronto, 12-31 pg m(-3) and Chicago,13-52 pg m(-3)). The high concentrations at urban sites were attributed to continued emissions of historically used technical PCN. Contributions from combustion-derived PCNs seemed to be more important at rural locations where congeners 24 and 50, associated with wood and coal burning, were elevated. Congener 66/67, associated with incineration and other industrial thermal processes, was elevated at two sites and explained by nearby and/or upwind sources. Probability density maps were constructed for each site and for every integration period were shown to be a useful complement to seasonally integrated passive sampling data to resolve source-receptor relationship for PCNs and other pollutants.

Formation and control of toxic polychlorinated compounds during incineration of wastes containing polychlorinated naphthalenes

To estimate the potential impact on municipal solid waste (MSW) incinerator toxic equivalent (TEQ) emissions of treating wastes containing polychlorinated naphthalenes (PCNs), pilot-scale thermal treatment experiments were conducted. MSW (run 1) and MSW fortified with synthetic rubber belts containing PCNs (runs 2 and 3) were incinerated. Flue-gas and ash samples were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (co-PCBs), and PCNs. Final exhaust-gas WHO-TEQ emissions were all less than 0.1 ng/Nm3. Flue-gas TEQs were mainly from PCDFs (58-74%). When 2,3,7,8-tetrachlorodibenzo-p-dioxin relative potency factors (REPs) of specific PCN congeners from previous reports were used as estimated toxic equivalency factors to compute estimated PCN TEQs and total TEQs along with PCDDs, PCDFs, and co-PCBs, the contributions of PCNs to the total TEQs were small in ash samples and up to 28% in final exhaust gas. The TEQs in primary combustion flue gases increased through the formation of dioxins and PCNs and then decreased via secondary combustion, fabric filtration, and activated carbon adsorption. From this pilot-scale study, the incremental impact of incinerating PCN-containing wastes on annual TEQ emissions in Japan is estimated as 0.27 g of total TEQ.

Prediction of environmental partition coefficients and the Henry's law constants for 135 congeners of chlorodibenzothiophene

Polychlorinated dibenzothiophenes (PCDTs) could be classified as persistent organic pollutants (POPs) in the environment and are particularly interesting due to their structural resemblance to highly toxic dioxins. We show here some basic environmental properties such as n-octanol water (K(OW)), n-octanol/air (K(OA)) and air/water (K(AW)) partition coefficients as well as Henry's law constants (K(H)) for all 135 congeners of chlorodibenzothiophene. Predictions were made by regression of principal components (PCR) and with aid of a set of standard chemicals, for which physical-chemical properties are well featured. Computed K(OW), K(OA), K(AW) and K(H) values for mono-CDTs ranged, respectively, between 4.66 and 4.71, 7.48 and 7.55, -2.84 and -2.82, 3.56 and 3.74; for di-CDTs between 5.02 and 5.28, 8.03 and 8.29, -3.01 and -2.95, 2.42 and 2.75; for tri-CDTs between 5.53 and 5.70, 8.65 and 8.87, -3.2 and -3.11, 1.58 and 1.92; for tetra-CDTs between 5.95 and 6.13, 9.27 and 9.50, -3.39 and -3.27, 1.02 and 1.33; for penta-CDTs between 6.38 and 6.51, 9.88 and 10.05, -3.54 and -3.45, 0.72 and 0.88; for hexa-CDTs between 6.83 and 6.97, 10.54 and 10.66, -3.72 and -3.64, 0.47 and 0.56; for hepta-CDTs between 7.28 and 7.35, 11.12 and 11.20, -3.81 and -3.87, 0.33 and 0.38; for octa-CDT 7.74, 11.78, -4.04 and 0.23. An estimated value of the three types of partition coefficient and Henry's law constants suggest that polychlorinated dibenzothiophenes are lipophilic and semi-volatile persistent organic pollutants. Their mobility in the environment seems to be very similar to that of some well-known POPs such as polychlorinated dibenzofurans, -dibenzo-p-dioxins, and -biphenyls or organochlorine pesticides.

Behavior of PCNs, PCDDs, PCDFs, and dioxin-like PCBs in the thermal destruction of wastes containing PCNs

In the first known study to characterize the emissions of polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) from the thermal treatment of wastes containing PCNs, the formation and decomposition behavior of these pollutants was investigated both at laboratory scale and at plant scale. Exhaust gas measurements from laboratory-scale combustion of rubber belts containing PCNs (FB belts) were used as the basis for calculations predicting that the incremental dioxin toxic equivalency (TEQ) emissions from municipal solid waste (MSW) incinerators would be less than 0.1 ng/m3 N. In order to directly examine co-incineration of FB belts with MSW and to address potential differences between the laboratory experiment and full-scale MSW incinerators, experiments were conducted using a larger scale thermal treatment test facility with sampling and analysis at several points in the thermal treatment process. Congener specific analysis of PCNs clearly showed that both destruction and synthesis simultaneously occurred during combustion in the kiln. Most of the PCNs were destroyed by secondary combustion, and almost all PCNs were removed after flue gas treatment. Almost all PCDDs/DFs were synthesized as by-products of kiln combustion, most of them were destroyed by the secondary combustion, and almost all dioxins (PCDDs/DFs and dl-PCBs) were removed after flue gas treatment. The TEQ emission levels were less than 0.1 ng/m3 N for all plant-scale tests, and differences in TEQ emission levels were very small. Adding wastes containing PCNs to MSW will not influence thermal treatment emissions to the environment from modern solid waste incinerators.

The dependence of organohalogen compound concentrations on herring age and size in the Bothnian Sea, northern Baltic

The concentrations and composition profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, polybrominated diphenyl ethers and polychlorinated naphthalenes were determined in herring individuals collected from the commercial catches of the Bothnian Sea, northern Baltic. The median age of herring was 5.0 years and in the muscle the median toxic equivalent concentration of PCDD/Fs was 5.6 WHO(PCDD/F)-TEQ pg/g fresh weight (fw) and that of PCBs 2.7 WHO(PCB)-TEQ pg/g fw. The median sum concentration of PBDEs was 1.4 ng/g fw and that of PCNs 0.1 ng/g fw. Differences in age-dependent accumulation between the organohalogen groups and individual congeners were major. In the Bothnian Sea the content of organohalogen compounds in herring is obviously elevated due to the availability and large proportion of Mysis crustaceans in their diet. More intensive fishing could reduce the concentrations of organohalogens, including the abundant, accumulative and toxic 2,3,4,7,8-PeCDF congener in the Baltic herring catch.

Verifying emission factors and national POPs emission inventories for the UK using measurements and modelling at two rural locations

Different approaches are used to verify the adequacy of emission factors (EFs) and their use in emission inventories of persistent organic pollutants (POPs). The applicability of EFs was tested using atmospheric dispersion modelling to predict atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and resulting toxic equivalents (SigmaTEQ) and particulate matter <10 microm (PM(10)) in two rural locations in northern England (UK). The modelling was based on general assumptions of fuel composition, consumption and heating needs to simulate emissions of POPs from the domestic burning of coal and wood where ambient measurements were made in the winter of 1998. The model was used to derive the local contribution to ambient air concentrations, which were estimated independently based on comparative air measurements. The results support the hypothesis that in both villages, the majority of PAHs and the lower chlorinated PCDFs were locally released. The situation for PCBs and polychlorinated naphthalenes (PCNs) was different. While the EFs show the release of both compound groups from the domestic burning of coal and wood, the ambient levels of these "legacy POPs" in the villages were still clearly dominated by other sources. Rural areas relying mainly on fossil fuels can exceed the proposed UK ambient air quality standard for benzo[a]pyrene during winter. The measured EFs were then used to estimate the importance of the domestic burning of coal and wood to national emission inventories for these compound classes. Extrapolations to the UK suggest that the domestic burning of pure wood and coal were minor emitters for chlorinated POPs but contributed strongly to PAH and PM(10) levels in 2000. Finally, the UK's national POPs emission inventories based on source inventories and EF, as used here, were compared to estimates derived using the increase in atmospheric concentration of selected POPs.

Chloronaphthalenes composition of several batches of Halowax 1051

Halowax 1051 is the highest chlorinated technical chloronaphthalene mixture among seven known formulations of the Halowax series. Octa- and heptaCN homologue groups are the main CN constituents of Halowax 1051 with declared 90% and 10% contents, respectively. In this study, using an isotope dilution technique and HRGC/HRMS, octaCN and heptaCNs contents of six batches of Halowax 1051 were between 82-93% and 6.2-17%, respectively. Also mono- to hexaCNs were found in Halowax 1051, and their content more or less varied according to the batch; also, the abundance of a particular CN congeners varied. Tetra-, penta- and hexaCNs have been found in all six batches of Halowax 1051 examined, and their contents varied between 0.0024-0.77%, 0.031-0.22%, and 0.21-0.82%, respectively. TriCNs have been found in three of six batches, and mono- and diCNs in two of six batches with 0.0020-0.40, 0.0017-0.25 and 0.0012-0.34% for positive findings, respectively. 2,3-DiCN (no. 10), 1,8-diCN (no. 9) at < 0.0002 mg/g, 1,6,7-/2,3,6-triCNs (nos. 25/26), 1,3,8-triCN (no. 22) at < 0.0002 mg/g, 1,3,6,7-tetra (no. 44), 1,2,3,6-tetra- (no. 29), 1,2,7,8-tetraCN (no. 41) and 1,2,3,6,7,9-hexaCN (no. 70) at < 0.0005 mg/g have not been found in Halowax 1051.

HRGC/HRMS analysis of chloronaphthalenes in several batches of Halowax 1000, 1001, 1013, 1014 and 1099

Chloronaphthalene (CN) congeners and homologue groups have been quantified in up to three batches of several types of technical CN formulations of the Halowax series (Halowax 1031, 1000, 1001, 1013, 1014 and 1099), to elucidate possible batch-to-batch compositional variations. Using isotope dilution and HRGC/HRMS a relatively large variation in CN congeners and homologues composition among the batches of particular types of the Halowax formulations could be noted, and also when compared to the composition declared by the manufacturer. Depending on the type of the Halowax formulation and its batch in total up to 54 peaks from chloronaphthalenes (Agilent Ultra 2 liquid phase), which represented 70 of 75 CN congeners theoretically possible, could be found in these mixtures. These congeners represented all CN homologue groups from mono- to octaCN but some co-eluted. A co-eluting congeners were such as: 1,4-/1,6- (nos. 5/7), 1,5-/2,7- (nos. 6/12), 2,6-1,7- (nos. 11/8) of diCNs; 1,3,6-/1,3,5- (nos. 20/19), 1,3,7-/1,4,6- (nos. 23/24), 1,6,7-/2,3,6- (nos. 25/26) of triCNs; 1,2,5,7-/1,2,4,6-/1,2,4,7- (nos. 37/33/34), 1,3,6,8-/1,2,5,6- (nos. 45/36), 1,2,3,5-/1,3,5,8- (nos. 28/43), 1,2,3,4-/1,2,3,7- (nos. 27/30), 1,2,5,8-/1,2,6,8- (nos. 38/40) of tetraCNs; 1,2,3,5,7-/1,2,4,6,7- (nos. 52/60), 1,2,3,5,8-/1,2,3,6,8- (nos. 53/55) of pentaCNs; 1,2,3,4,6,7-/1,2,3,5,6,7- (nos. 66/67), 1,2,3,4,5,7-/1,2,3,5,6,8- (64/68) and 1,2,4,5,6,8-/1,2,4,5,7,8- (nos. 71/72) of hexaCNs. Absent in the Halowaxes were CN congeners such as 1,3,8-triCN (no. 22) (<0.0002 mg/g), 1,3,6,7-tetraCN (no. 44), 1,2,3,6-TetraCN (no. 29), 1,2,3,6,7-pentaCN (no. 54) and 1,2,3,6,7,8-hexaCN (no. 70) (<0.0005 mg/g).

Halogenated compounds in a dated sediment core of the Teltow Canal, Berlin: time related sediment contamination

To study the recent contamination history of DDT (1,1,1-trichloro-2,2-bis(chlorophenyl)ethane) and its metabolites, as well as methoxychlor (1,1,1-trichloro-2,2-bis(p-methoxyphenyl)ethane), chlorfenson (4-chlorophenyl-p-chlorobenzenesulfonate), and further halogenated aromatics, a sediment core was collected from the Teltow Canal in Berlin (Germany). The sampling site is located nearby a former industrial point source, where recently analyses on pre-samples have indicated high concentrations of halogenated organic compounds. The deposition time of the investigated sediments was determined by gamma-spectrometrical dating. Pollution trends of selected contaminants were attributed to a time period between 5 and 10 years. Concentration profiles reflect not only the recent pollution history of these compounds, but also the time-depending effects of the ban, restriction and termination of DDT-production in the German Democratic Republic (GDR). DDT and other chlorinated aromatic compounds were produced onsite until the late 1980s. Maximum values of 133 mg kg(-1) (dry weight) for p,p'-DDD (1,1-dichloro-2,2-bis(chlorophenyl)ethane) and approximately 100 mg kg(-1) (dry weight) for p,p'-DDMS (1-chloro-2,2-bis(chlorophenyl)ethane), main metabolites of the anaerobic degradation of DDT, were determined. The occurrence of all selected contaminants, most of which have been banned more than 10 years ago, demonstrate recent contamination pathways, and the necessity of a continuous long-term monitoring of the affected environment.

Exposure to polychlorinated naphthalenes affects GABA-metabolizing enzymes in rat brain

There is substantial evidence that polychlorinated naphthalenes (PCNs) are widespread global environmental pollutants, which accumulate in biota. The aim of our study was to characterize the effect of prolonged PCNs exposure on γ-aminobutyric acid (GABA) metabolism in rat brain regions with a high amount of GABAergic neurons (cerebellum, brain stem and basal ganglia). PCNs mixture was administered intragastrically for 7, 14 and 21 days in a dose 10mg/kg of body weight daily, and next the activity of glutamate decarboxylase (GAD), GABA-aminotransferase (GABA-T), succinic semialdehyde dehydrogenase (SDH) and succinate dehydrogenase (SSA-DH) was assayed. PCNs administration altered all examined activities in the selected brain areas, except GAD in basal ganglia. The results suggest the correlation between PCNs action and disturbance in GABA metabolism in rat brain. Moreover, the chronic PCNs intoxication increased SDH-mediated activation of TCA cycle, and it may be a kind of protective mechanism developed in nervous tissue in response to administration of toxic compounds.

Groundwater contamination by chlorinated naphthalenes and related substances caused by activities of a former military base

Water samples derived from two different aquifer layers of six sampling sites were analysed by GC/MS in order to characterize a groundwater contamination caused by chemicals used for wood impregnation. Mono- and dichlorinated naphthalenes, chlorobenzo(b)thiophene, 1-chloro-4-naphthol, 1-chloronaphthoic acid, acenaphthene and methyled naphthalenes were identified as the main pollutants and quantified. 1-Chloro-4-naphthol and 1-chloronaphthoic acid are discussed as possible indicators for anaerobic degradation processes. Results of inorganic and compound specific stable carbon isotope analyses revealed only a minor degree of microbiological transformation. Thus, sorption was characterized as the main attenuation process within the aquifer affecting the contamination described.

Detailed study of factors controlling atmospheric concentrations of PCNs

Atmospheric concentrations of polychlorinated naphthalenes (PCNs) (108 samples in total) were measured at two rural/ semirural sites in England and one remote site on the west coast of Ireland in the years 2001 and 2000, respectively. Detailed analysis of the factors affecting concentrations is performed. At Mace Head (MH) Ireland, concentrations of sigmaPCNs ranged between 1.7 and 55 pg m(-3) with a mean of 15 pg m(-3) and were controlled primarily by advection. sigmaPCNs concentrations at Hazelrigg (HR), northwest England, ranged between 31 and 310 pg m(-3) with a mean of 110 pg m(-3), and at Chilton (CH), southwest England, ranged between 31 and 180 pg m(-3) with a mean of 85 pg m(-3). Data from the HR site shows that PCN concentrations have not declined between the early 1990s and 2001, while PCB concentrations have declined. The ratio of the sigmaPCNs/ sigmaPCBs was close to or greater than 1 at all sites. From air mass back trajectories, it is clear that local/regional sources influenced concentrations of PCNs at all sites, particularly at MH. At the two English sites during the summer, concentrations of PCNs were strongly influenced by temperature, indicating that air-surface exchange processes play an important role. Advection became more influential during winter, particularly at CH, where a different homologue profile was observed in some samples when air masses approached from the southwest and PCN concentrations increased. The average mixture profile of PCNs in air was similar to that observed in other studies and different from that in Halowax 1014.

Polychlorinated naphthalenes in air and snow in the Norwegian Arctic: a local source or an Eastern Arctic phenomenon?

PCNs were measured in air and snow during separate field campaigns at Ny-Alesund (April 2001) and Tromsø (February/March 2003) in the Norwegian Arctic. Air concentrations ranged from 27 to 48 and 9 to 47 pg sigmaPCN m(-3) for Ny-Alesund (n=6) and Tromsø (n=10), respectively. These concentrations (including the tri-chlorinated naphthalenes) greatly exceeded concentrations previously measured in the Canadian Arctic, but did fall within the upper range of concentrations observed over the eastern Arctic Ocean and regional seas. Local sources appear to be affecting concentrations observed at both sites, with the presence of several hexa-chlorinated naphthalenes at Tromsø probably attributed to local/regional sources. Use of air mass back trajectories at Tromsø revealed that background air concentrations in the Norwegian Arctic are likely to range between <9 and 20 pg sigmaPCN m(-3) and that contemporary concentrations derived close to potential sources (i.e. arctic towns) may equal or exceed those of PCBs. The mean concentration in surface snow was 350 and 240 pg sigmaPCN L(-1) (meltwater) (or 0.014 and 0.01 pg g(-1) (snow)) at Ny-Alesund and Tromsø, respectively. The wide variation in concentrations observed between fresh snowfalls could be explained by different snow densities (as a surrogate of snow surface area), rather than attributed to varying air concentrations. A statistically significant inverse relationship was found between snow density and concentrations of tri- to penta-chlorinated homologues and compliments similar findings for the polychlorinated biphenyls (PCBs). This suggests that the vapour-sorbed quantity changes rapidly with snow ageing/compaction; with implications for the fate of these chemicals in the Arctic.

Emission factors and importance of PCDD/Fs, PCBs, PCNs, PAHs and PM10 from the domestic burning of coal and wood in the U.K

This paper presents emission factors (EFs) derived for a range of persistent organic pollutants (POPs) when coal and wood were subject to controlled burning experiments, designed to simulate domestic burning for space heating. A wide range of POPs were emitted, with emissions from coal being higher than those from wood. Highest EFs were obtained for particulate matter, PM10, (approximately 10 g/kg fuel) and polycyclic aromatic hydrocarbons (approximately 100 mg/ kg fuel for sigmaPAHs). For chlorinated compounds, EFs were highest for polychlorinated biphenyls (PCBs), with polychlorinated naphthalenes (PCNs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) being less abundant. EFs were on the order of 1000 ng/kg fuel for sigmaPCBs, 100s ng/ kg fuel for sigmaPCNs and 100 ng/kg fuel for sigmaPCDD/Fs. The study confirmed that mono- to trichlorinated dibenzofurans, Cl1,2,3DFs, were strong indicators of low temperature combustion processes, such as the domestic burning of coal and wood. It is concluded that numerous PCB and PCN congeners are routinely formed during the combustion of solid fuels. However, their combined emissions from the domestic burning of coal and wood would contribute only a few percent to annual U.K. emission estimates. Emissions of PAHs and PM10 were major contributors to U.K. national emission inventories. Major emissions were found from the domestic burning for Cl1,2,3DFs, while the contribution of PCDD/F-sigmaTEQ to total U.K. emissions was minor.

Analysis of organochlorines in harbor seal (Phoca vitulina) tissue samples from Alaska using gas chromatography/ion trap mass spectrometry by an isotopic dilution technique

A gas chromatography/ion trap mass spectrometry (GC/ITMS) method was developed for the determination of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in harbor seal (Phoca vitulina) tissues. Tissue samples were homogenized, lyophilized and fortified with (13)C-PCBs 28, 123, 169 and 170, and then extracted with an accelerated solvent extractor with a mixture of hexane and methylene chloride (1:1, v/v). After lipid removal using a 40% H(2)SO(4)-modified silica gel column, all organochlorines were collected in one fraction and further fractionated with an activated carbon/silica gel (1:20) column into a first fraction containing OCPs, non-coplanar PCBs and (13)C-PCBs 28, 123 and 170, and a second containing PCNs, coplanar PCBs and (13)C-PCB 169. Prior to GC/MS/MS analysis, (13)C-PCB 169 was added into the first fraction as an injection standard and (13)C-PCB 170 into the second fraction to calibrate the recoveries of the fortified internal standards. This method can effectively eliminate matrix interferences, and has high selectivity and sensitivity. Recoveries averaged 45-86% for OCPs with relative standard deviations (RSDs) of 2-14%, 52-137% for PCBs with RSDs of 3-29% and 36-152% for PCNs with RSDs of 7-29% from lard and chicken heart samples, which were used as alternative matrices to harbor seal samples in recovery studies. The limits of detection for OCPs, PCBs and PCNs were 0.7-1.9, 1.5-8.9 and 0.5-10 pg/g dry weight, respectively. This method can be used to analyze OCPs, PCBs and PCNs in harbor seal blubber, liver and kidney samples.

By-side impurities in chloronaphthalene mixtures of the Halowax series: all 135 chlorodibenzofurans

One hundred twenty five congeners of CDF off 135 theoretically possible were quantified in seven of various type Halowax formulations but still 45 co-eluted under the gas chromatographic conditions applied. The total CDFs concentration of Halowax formulations was between 250 and 16,000 ng/g. The compositional profile of CDF homologue groups of the Halowaxes frequently followed a degree of chlorination of the parent chloronaphthalene mixture and an exception was Halowax 1031. The compositional profile of many isomers of trichlorodibenzofuran, found and often highly abundant, was characteristic to majority of the formulations examined, and each of them demonstrated to have its own pattern but mysterious to explain remained Halowax 1031. In term of dioxin-like toxicity the most potent due to CDFs content was Halowax 1014 with 210 ng TCDD TEQ/g and next was Halowax 1013 with 36 ng TEQ/g, while between 1.3 and 5.0 ng TEQ/g were for other formulations. A tentative estimation made implies that the net total CDFs production due to manufacture of the technical CNs in the XX century could reach an amount between 420 kg (median) and 825 kg (mean), and for most toxic dioxin-like congeners between 705 g (median) and 5700 g (mean) TCDD TEQ, while for the worst case of Halowax 1014 alone scenario it could be 750 kg of the total CDFs and 16 kg of TCDD TEQ for most toxic congeners.

By-side impurities in chloronaphthalene mixtures of the Halowax series: all 75 chlorodibenzo-p-dioxins

A by-side chlorodibenzo-p-dioxins (CDDs) has been identified as impurity in concentration between 1.5 and 370 ng/g in the Halowax formulations of all type. Halowax 1014 was relatively richer in number of CDD congeners detected when compared to six other CN formulations examined. Amongst the mono- to tri-CDDs, the most prevalent in the Halowaxes were 1- and 2-MoCDD, and especially they were abundant in the formulations of a lower than a higher degree of chlorination. Amongst the tetra- to octaCDD only 1,2,3,4-/1,2,4,6-/1,2,4,9-/ 1,2,3,8-TeCDD, 1,2,3,4,6,7,8-HpCDD and OcCDD were found in all the Halowaxes, and 1,2,3,4,6,7,9-HpCDD remained undetected only in Halowax 1099 and 1013, while most of TeCDDs, PeCDD, and HxCDDs were absent in a majority of the formulations examined. The compositional profile of 1,2,3,4-/1,2,4,6-/1,2,4,9,-/1,2,3,8-TeCDD and OcCDD congeners found in the Halowaxes seem to indicate, that after an initial in situ formation of mono- and di-CDDs during CNs synthesis, a further increase of reaction time, temperature, and pressure can lead to successive chlorination of the already established chlorodibenzo-p-dioxin molecule, and so to enrichment in 1,2,3,4-/ 1,2,4,6-/1,2,4,9,-/1,2,3,8-TeCDD but also OcCDD content for most of the final products obtained. Nevertheless, also due to the co-synthesis of chlorophenols in the Halowaxes, their condensation reactions could also contribute to the formation of CDDs. In term of dioxin-like toxicity the most potent due to CDDs content was Halowax 1014 with 0.95 ng TCDD TEQ/g, and between 0.00068 and 0.058 ng/g were for other formulations. A rough estimation made implies that a net CDDs production due to manufacture of the technical CNs in the XX century could reach an amount between 3.0 and 12.6 kg, while for most toxic dioxin-like constituents between 5.25 and 24 g TCDD TEQ, For the worst case scenario and involvement of Halowax 1014 only the net total CDDs production was estimated to be 1.5 kg, and for highly-toxic congeners 71 g TCDD TEQ. All these figures are much lower when compared to co-production of CDFs.

Octanol/water partition coefficients of chloronaphthalenes

Computational n-octanol/water partition coefficients data for 75 chloronaphthalene congeners based on the Ghose, Pritchet, and Crippen algorithm; the Moriguchi method; and two QSPR models with principal component regression and partial least-squares (PLS) regression calculations are presented. Chloronaphthalenes log Kow data obtained after PLS are characterized by the lowest root mean square error (RMSEP = 0.0190), whereas results from the Ghose, Pritchet, and Crippen algorithm are characterized by the worst predictive ability (RMSEP = 0.4191). Minimal values of log Kow of chloronaphthalenes ranged between 3.57 and 3.90 for 1-chloronaphthalene, whereas maximal values ranged between 6.36 and 7.19 for octachloronaphthalene.

Gull eggs—food of high organic pollutant content?

A wide range and occasionally high levels of persistent organic pollutants (POPs) are reported in Arctic regions, especially among top predators. Polar bears (Ursus maritimus), arctic foxes (Alopex lagopus) and some gull species (Larus spp.) often have high levels of these fat-soluble pollutants. Gulls deposit significant levels of these contaminants in their eggs. In northern regions, gull eggs are part of the traditional human diet. In the present study we have investigated the levels of POPs in gull eggs in order to determine the tolerable weekly intake (TWI) for humans. Concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were measured in 214 gull eggs collected in the spring of 2001-02. The eggs were collected from four gull species (herring gulls (Larus argentatus), great black-backed gulls (L. marinus), lesser black-backed gulls (L. fuscus) and glaucous gulls (L. hyperboreus)) at 12 different locations in Northern Norway, on the Faroe Islands and on Svalbard. The pollutant levels in gull eggs were found to be 65.5 +/- 26.9 pg toxic equivalent (TE) for dioxin and PCB g(-1) wet weight. Based on these findings and the TWI-value determined by the EU Scientific Committee on Food it is advised that children, young women and pregnant and nursing women should not eat gull eggs. Other people should limit their intake of eggs to an absolute minimum, considering the health risks associated with gull egg intake.

Gas chromatography–ion trap tandem mass spectrometry versus GC–high-resolution mass spectrometry for the determination of non-ortho-polychlorinated biphenyls in fish

Gas chromatography coupled with ion trap tandem mass spectrometry (GC-MS-MS) has been compared to gas chromatography-high-resolution mass spectrometry (GC-HRMS) for the analysis of non-ortho-chlorinated biphenyl (CB) congeners in fish samples. The MS-MS operating parameters related to the isolation and fragmentation of the precursor ions by resonant collision induced dissociation (CID) were optimised in order to achieve maximum sensitivity and selectivity. Analytical procedure consisting of Soxhlet extraction, clean-up using a multilayer silica column and the isolation of the target compounds with SPE commercial carbon cartridges packed with Carbopack B has been applied. Quality parameters have been established using standard solutions and fish samples. Good repeatability, long-term precision (lower than 10%), and limits of detection between 0.12 and 0.16 pg g(-1) were obtained. The effect of potential interfering compounds such as polychlorinated naphthalenes in the quantification of non-ortho-CBs has been investigated. Using selective CID fragmentation conditions, the effect of these compounds was minimised. The GC-MS-MS method was validated by comparing the results with those obtained in two European intercomparison exercises.

Seasonal and spatial variation of polychlorinated naphthalenes and non-/mono-ortho-substituted polychlorinated biphenyls in arctic air

Archived extracts of weekly air samples collected at remote arctic monitoring stations at Alert and Tagish, Canada, and Dunai Island, Russia, in 1994-1995 were combined into 4-week composites and analyzed for levels and seasonal trends of polychlorinated naphthalenes (PCNs) and non- and mono-ortho-substituted polychlorinated biphenyls (PCBs). Mean annual sigmaPCN concentrations were 0.69, 0.82, and 0.38 pg/m3 at Alert, Dunai, and Tagish, respectively. PCNs exhibited a seasonal trend at Alert and Dunai, with higher levels occurring during winter when air masses originating over Eurasia influence the high arctic and coincide with the haze period. Episodic, trans-Pacific transport impacted PCN concentrations at Tagish. A seasonal trend was not evident for the non-/mono-o-PCBs. The contrary PCN and non-/mono-o-PCB trends indicate that the sources of these two compound classes to arctic air differ, and that atmospheric transport from source regions has a greater influence on PCN levels than for non-/ mono-o-PCBs. PCNs apparently originating from combustion sources contribute to levels in winter, as indicated by the presence of combustion marker congeners, but evaporative emissions from source regions are likely the dominant source. PCNs contributed 71 and 75% of dioxin toxic equivalents (TEQ) relative to the non-/mono-o-PCBs at Alert and Dunai and 30% at Tagish during the winter months, demonstrating the toxicological importance of PCNs as a compound class relative to PCBs.

Polychlorinated naphthalenes in Swedish background air

Polychlorinated naphthalenes (PCNs) with four to eight chlorines were studied in air collected at two background stations in Sweden, one southerly and one northerly. Air was sampled with a high-volume sampler, and gas-phase adsorbents and filters were analyzed separately. The sum of TeCNs to HxCNs in the gaseous phase ranged between 1 and 10 pg/m3 with significantly higher concentrations at the southern location Hoburgen. HpCNs and OCN were below the detection limit. The highest concentrations were found in two samples from Hoburgen with the air masses coming from SW and W and during warm weather (+11 degrees C). The lowest concentration was found in a sample from the northern location Ammarnäs at cold weather (-22 degrees C) when the air came from the east. A correlation was found between logP and 1/T indicating that temperature has a larger effect than location on the concentration in the gas phase. The TeCNs constituted 50-75% in the gaseous phase. In most filter samples TeCNs and PeCNs were below the limit of quantitation. PUF samples with air trajectories from W to NE had relatively higher concentrations of late eluting TeCNs and PeCNs, while in samples with winds from SE to S the early eluting congeners dominated. Samples with early eluting congeners were mainly collected at lower temperature. TriCNs constituted the dominant homologue group both in the gaseous and particulate phase of air samples as well as in bulk deposition from a rural monitoring station south of Stockholm. The octanol-air partition coefficient described the gas/particle interaction well for samples collected at temperatures down to -8 degrees C.

Polychlorinated naphthalenes in animal aquatic species and human exposure through the diet: a review

Polychlorinated naphthalenes (PCNs) are a group of environmental pollutants, which contain one to eight chlorine atoms per naphthalene molecule, forming a total of 75 possible congeners. Several of the PCN congeners display toxicity similar to that of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) through AhR-mediated mechanisms. There are toxicological similarities between PCNs and other well known environmental contaminants such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs). However, in contrast to these compounds, information on exposure to PCNs for non-occupationally exposed populations is rather scarce. In this article, information on human exposure to PCNs through dietary intake is reviewed. Because this information is very limited and taking into account that most data on PCN levels in potential foods concern to aquatic species, these data are also reviewed. It is concluded that further investigations on dietary intake and potential human health effects of PCNs are clearly necessary.

PBDEs, PBBs, and PCNs in three communities of free-ranging killer whales (Orcinus orca) from the northeastern Pacific Ocean

Polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), and polychlorinated naphthalenes (PCNs) were quantified in blubber biopsy samples collected from free-ranging male and female killer whales (Orcinus orca) belonging to three distinct communities (southern residents, northern residents, and transients) from the northeastern Pacific Ocean. High concentrations of sigmaPBDE were observed in male southern residents (942+/-582 ng/g Iw), male and female transients (1015+/-605 and 885+/-706 ng/g Iw, respectively), and male and female northern residents (203+/-116 and 415+/-676 ng/g Iw, respectively). Because of large variation within sample groups, sigmaPBDE levels generally did not differ statistically with the exception of male northern residents, which had lower sigmaPBDE concentrations than male southern residents, male transients, and female transients, perhaps reflecting the consumption of less contaminated prey items. Male transient killer whales, which consume high trophic level prey including other cetaceans and occasionally spend time near populated areas, had sigmaPBDE concentrations approximately equal to southern residents. No significant age-related relationships were observed for sigmaPBDE concentrations. sigmaPBDE concentrations were approximately 1-3 orders of magnitude greater than those of sigmaPBB (3.0-31 ng/g Iw) and sigmaPCN (20-167 ng/g Iw) measured in a subset of samples, suggesting that PBDEs may represent a contaminant class of concern in these marine mammals.

A case study of contaminants on military ranges: Camp Edwards, Massachusetts, USA

An extensive investigation at the Camp Edwards, Massachusetts Military Reservation (MMR) demonstrates that assessment of groundwater and soil contamination at military ranges can be limited primarily to explosive-related compounds such as RDX, HMX, perchlorate, TNT and their transformation products. A modified analytical method is recommended to expand the list of explosives and to improve the detection limits. Analyses of metals, VOCs, SVOCs, and TICs are unnecessary. Soil samples may require the analyses of PAHs and PCNs for burn areas. Camp Edwards, as one of the few military ranges that have been exhaustively investigated for contaminants, is an ideal point of departure for evaluating other ranges. The permeable site soils promote leaching of contaminants and inhibit biotic and abiotic transformations. Moreover, the site has experienced an unusual extent of activities in its more than ninety years of active use. The recommendations in this report are based on data obtained for more than 200 analytes from more than 15,000 environmental samples.

Levels of PCDD/Fs, PCBs, and PCNs in soils and vegetation in an area with chemical and petrochemical industries

The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs) have been determined in soil and wild chard samples collected in an area of Tarragona County (Catalonia, Spain) with an important number of chemical and petrochemical industries. Samples were also collected in urban/residential zones, as well as in presumably unpolluted sites. In soils, the levels of PCDD/Fs ranged from 0.16 ng I-TEQ/kg (unpolluted sampling points) to 2.65 ng I-TEQ/kg (industrial zone), and those of sigmaPCBs ranged from 657 to 12038 ng/ kg in these same zones. In turn, sigmaPCNs ranged from 32 (unpolluted sites) to 180 ng/kg (residential/urban sites). In contrast to soil concentrations, there were not significant differences among collection zones in the levels of PCDD/Fs, PCBs, and PCNs found in chard. However, PCB and PCN concentrations in chard samples collected at the unpolluted sampling points were higher than the respective concentrations in soils. In general terms, the current concentrations of the organic pollutants analyzed in this study are similar or lower than data from previous reports in other countries.

Congener-specific composition of polychlorinated naphthalenes, coplanar PCBs, dibenzo-p-dioxins, and dibenzofurans in the Halowax series

Concentrations and congener compositions of polychlorinated naphthalenes (PCNs), coplanar polychlorinated biphenyls (Co-PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) were determined in seven Halowax (HW) preparations. In HW 1000 and 1031, low-chlorinated naphthalenes (CNs) and in HW 1051, highly chlorinated naphthalenes were dominant, whereas tri- through penta-CNs were major homologues in other Halowaxes. Concentrations of Co-PCBs were in the range of 2.0-2600 ng/g. CB 105 and 118 were dominant in all Halowaxes. Concentrations of PCDDs/DFs were in the range of 92-5900 ng/g. The 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) in Halowaxes calculated from the amounts of PCNs, Co-PCBs, and PCDDs/DFs were in the range of 2800-220,000 ng-TEQ/g. PCNs accounted for most of the total TEQs in Halowaxes, and the contribution of PCDDs/DFs and Co-PCBs to total TEQs was less than 1/1000 that of PCNs. Congeners that most significantly contributed to TEQs were CN 69, 73, 70, and 63. Total TEQs roughly estimated from the Japanese production of technical PCNs, 210 kg-TEQ, was about half from technical PCBs, 440 kg-TEQ on average.

By-side impurities in chloronaphthalene mixtures of the Halowax series: all 19 chlorophenols

All seven Halowax formulations examined were contaminated with chlorophenols (CPhs). The total CPhs content of the CN mixtures ranged from 1050 to 34,200 ng/g. The absolute concentration of CPhs decreased with an increase of degree of chlorination (% Cl) of the Halowax 1031 (27%), 1000 (35%), 1001 (49%), and 1099 (51%), respectively, but remained relatively constant for higher chlorinated Halowax 1099 (51%), 1013 (54%), 1014 (59%), and 1051 (70%). 2,4,6-TrCPh and 2,4-DiCPh did contaminated all seven Halowax formulations and PeCPh remained undetected (<90 ng/g) only in Halowax 1099, while less frequently occurred 2,6-DiCPh and followed by 3-/4-MoCPh, 2,5-DiCPh, 2-MoCPh, 2,3-DiCPh, and 2,3,4,6-TeCPh. The CPh congeners such as 3,4-DiCPh, 3,5-DiCPh, 2,3,4-TrCPh, 2,3,5-TrCPh, 2,3,6-TrCPh, 2,4,5-TrCPh, 3,4,5-TrCPh, 2,3,4,5-TeCPh, and 2,3,5,6-TeCPh were undetected in any of the Halowax formulation examined. The profile (%) of higher chlorinated CPh homologues like PeCPh in the Halowaxes followed somehow a degree of chlorination (Cl %) of the parent mixture, i.e., increased from 14, 22, 43, 55, 52 to 80%, respectively, but exception was free of PeCPh the Halowax 1099. And contrary, for a lower chlorinated DiCPhs and TrCPhs their relative proportions decreased but again an exception was Halowax 1099. The fingerprint profiles of 2,4,6-TrCPh, 2,4-DiCPh, and PeCPh, which were usually the most abundant congeners varied and were less consisted when compared to the CPh homologue group profiles, and also more depended on the type of technical Halowax mixture. Due to absence of 2,4,5-TrCPh but presence of 2,4-DiCPh, 2,6-DiCPh, 2,4,6-TrCPh, and PeCPh, which, respectively, are indicative congeners for CPhs obtained by alkaline hydrolysis of chlorobenzenes or phenol chlorination using gaseous chlorine, just co-occurrence of phenol impurity in technical naphthalene is suggested as a solely source of CPhs in the Halowax mixtures.

By-side impurities in chloronaphthalene mixtures of the Halowax series: all 209 chlorobiphenyls

202 congeners of chlorobiphenyl (CB) with 109 single-resolved compounds and 93 co-eluting, which represented from mono- to deca-CB were quantified as by-side impurities in all seven and of various type the technical chloronaphthalene (CN) formulations of the Halowax series. IUPAC No. 104, 145, 159, 169, 184, 186, and 188 were undetected (<0.05-<0.7 ng/g). The total CBs content of the Halowax formulations ranged between 220 and 640,000 ng/g, and lower chlorinated Halowaxes 1031 (27% Cl) and 1000 (35% Cl) were two to three orders of magnitude more contaminated with CBs than higher chlorinated Halowax 1001, 1099, 1013, 1014, and 1051 (49-70% Cl). The profile of CB homologue groups of the Halowaxes changed and followed somehow a degree of chlorination of the parent CN mixture. For Halowax 1031 and 1000, a decreasing trend in proportion from mono- to deca-CB was evident, while for Halowax 1001, 1099, 1013, 1014, and 1051 the relative proportions between the CB homologue groups varied somehow. Evidently content of lower chlorinated mono- and di-CBs highly decreased and steadily increased tri- to octa-CBs and they become dominating homologues in Halowax formulations in parallel with an increase of the content of higher molecular weight CN constituents, respectively. Among planar non- and mono-ortho CBs, total concentrations in Halowax formulations were detected in the range of 2.0-2600 ng/g, and only 3,3',4,4',5,5'-HxCB (no. 169) was undetected (<0.05ng/g). Detection of by-side CBs in technical Halowaxes demonstrate clearly that those formulations apart from a massive introduction of dioxin-like CNs become in the past also an early source of environmental pollution with CBs, which proceeded for around 20-30 years use of original CB formulations.