Polychlorinated naphthalenes: an environmental update

Concentration and distribution of PCNs in ambient soil of a municipal solid waste incinerator

The impact of a typical municipal solid waste incinerator (MSWI) on polychlorinated naphthalene (PCN) concentrations in surrounding soil was studied. We collected 6 stack gas samples from the MSWI and 21 soil samples from sampling sites at distances of between 300 and 1,700 m from the MSWI stack. Total dl-PCN (dioxin-like PCN) concentrations in the stack gas samples ranged from 6898 and 89,032 pg m(-3), with a mean value of 36,241 pg m(-3). The total dl-PCN concentrations in the soil samples ranged from 30.35 to 280.9 pg g(-1), with a mean value of 87.03 and a median value of 70.32 pg g(-1), while the TEQ values were between 7.7 and 130.2 fg TEQ g(-1), with a mean value of 41.12 fg TEQ g(-1) and a median value of 31.52fg TEQ g(-1). The PCN homologue patterns and the results of Principal Component Analysis suggested that the MSWI may be a source of PCNs in the soils. A contour map, created using an ordinary Kriging interpolation technique, showed that a limited area (≤ 1,000 m radius) surrounding the MSWI was influenced by the emissions from the MSWI. Furthermore, an exponential function equation was proposed to quantify the relationship between TEQs of PCNs and the distance from the stack.

A review of new and current-use contaminants in the Arctic environment: evidence of long-range transport and indications of bioaccumulation

Systematic monitoring of persistent organic pollutants (POPs) in the Arctic has been conducted for several years, in combination with assessments of POP levels in the Arctic, POP exposure and biological effects. Meanwhile, environmental research continues to detect new contaminants some of which could be potential new Arctic pollutants. This study summarizes the empirical evidence that is currently available of those compounds in the Arctic that are not commonly included in chemical monitoring programmes. The study has focused on novel flame retardants, e.g. alternatives to the banned polybrominated diphenyl ethers (PBDEs), current-use pesticides and various other compounds, i.e. synthetic musk compounds, siloxanes, phthalic acid esters and halogenated compounds like hexachlorobutadiene, octachlorostyrene, pentachlorobenzene and polychlorinated naphthalenes. For a number of novel brominated flame retardants, e.g. 2,3-bibromopropyl-2,4,6-tribromophenyl ether (DPTE), bis(2-ethylhexyl)tetrabromophthalate (TBPH), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), 1,2-bis(2,4,6-tribromophenoxy)-ethane (BTBPE), decabromodiphenyl ethane (DBDPE), pentabromoethylbenzene (PBEB) and hexabromobenzene (HBBz), transport to the Arctic has been documented, but evidence of bioaccumulation is sparse and ambiguous. For short-chain chlorinated paraffins and dechlorane plus, however, increasing evidence shows both long-range transport and bioaccumulation. Ice cores have documented increasing concentrations of some current-use pesticides, e.g. chlorpyrifos, endosulfan and trifluralin, and bioaccumulation has been observed for pentachloroanisole, chorpyrifos, endosulfan and metoxychlor, however, the question of biomagnification remains unanswered.

Congener specific analysis, spatial distribution and screening-level risk assessment of polychlorinated naphthalenes in water and sediments from two tributaries of the River Chenab, Pakistan

The number of reports regarding PCN screening-levels and ecological risk assessment in environmental compartments is limited. This study presents information on congener specific analysis, distribution pattern of PCN and ecological risk assessment via PCN exposure/contamination through water and sediment from two tributaries of the River Chenab, Pakistan. A total twenty eight samples of water and sediment were collected during Jan, 2013 to June, 2013 to analyze the ∑39PCN congeners. ∑39PCN concentrations ranged between 8.94 and 414 ng g(-1) dw and 178-489 ng l(-1) in sediment and water, respectively. Water exhibited higher TEQ values while in case of sediments TEQ values were at higher than the previously reported data from other parts of the world. This is the first report of PCNs' distribution pattern and screening-level risk assessment from Pakistan. The results of toxicity exposure of PCN warrant auxiliary devotion in future, to this group of contaminant.

Thermal degradation of octachloronaphthalene over as-prepared Fe(3)O(4) micro/nanomaterial and its hypothesized mechanism

Decomposition of octachloronaphthalene (CN-75) featuring fully substituted chlorines was investigated over as-prepared Fe3O4 micro/nanomaterial at 300 °C. It conforms to pseudo-first-order kinetics with kobs = 0.10 min(-1) as comparable to that of hexachlorobenzene and decachlorobiphenyl. Analysis of the products indicates that the degradation of CN-75 proceeds via two competitive hydrodechlorination and oxidation pathways. The onset of hydrodechlorination producing lower chlorinated naphthalenes (CNs) is more favored on α-position than β-position. Higher amounts of CN-73, CN-66/67, CN-52/60, and CN-8/11 isomers were found, while small content difference was detected within the tetrachloronaphthalene and trichloronaphthalene homologues, which might be attributed to lower energy principle and steric effects. The important hydrodechlorination steps, leading to CN-73 ≫ CN-74 in two heptachloronaphthalene isomers contrary to that in technical PCN-mixtures, were specified by calculating the charge of natural bond orbitals in CN-75 and the energy of two heptachloronaphthalene radicals. On the basis of the molecular electrostatic potential of CN-75, the nucleophilic O(2-), and eletrophilic O2(-) and O(-), present on the Fe3O4 surface, might attack the carbon atom and π electron cloud of naphthalene ring, producing naphthol species with Mars-van Krevelen mechanism, and formic and acetic acids.

Destruction of polychlorinated naphthalenes by a high-temperature melting treatment (GeoMelt process)

A series of treatment experiments were carried out to evaluate the applicability of a high-temperature melting treatment (GeoMelt process) to the destruction of polychlorinated naphthalene (PCN) formulation. We started with 10-kg-scale experiments in which a small melting furnace was used and then scaled up to a 1-t-scale experiment in which a melting furnace that resembled an actual treatment system was used. These runs were evaluated whether destruction efficiency (DE) of total PCNs was more than 99.999% and whether concentrations of PCNs and polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/DFs) in vitrified materials, emission gas, and scrubber water were below the target levels. Because DE values and the target levels of PCNs and PCDDs/DFs in these runs were satisfactory, then we carried out a demonstrative experiment using the actual treatment system and confirmed destruction of PCNs. Based on good results of the demonstrative experiment, stock of PCN formulation was successfully treated continuously.

PCNs (polychlorinated napthalenes): dietary exposure via cereal crops, distribution and screening-level risk assessment in wheat, rice, soil and air along two tributaries of the River Chenab, Pakistan

There is a lack of scientific literature regarding the bioaccumulation, dietary and toxicity exposure of PCN via food crops. The current study presents the information of dietary intake, distribution pattern and screening level risk assessment of PCN in wheat, rice, soil and air along upstream feeding tributaries of the River Chenab, Punjab Province, Pakistan. A total six air and twenty eight of soil, wheat and rice samples were collected during Jan, 2013 to June, 2013 to analyze the thirty nine PCN congeners. ∑39PCN concentrations were ranged between 0.02 and 0.21 ng g(-1) dw, 0.02-1.21 ng g(-1) dw, 24.6-233 ng g(-1) dw and 1,222-5,052 pg m(-3) in wheat, rice, soil and air samples, respectively. In this study soil exhibited higher TEQ values while in case of air, wheat and rice TEQ concentrations were in accordance with the previously reported pattern from other parts of the world. Estimated daily intake (EDI) of ∑39PCN through consumption of wheat and rice was estimated as 0.21 ng kg(-1) (body weight)day(-1) and 0.03 ng kg(-1) (body weight)day(-1), respectively. This is the first report of PCN dietary intake and screening-level risk assessment by consumption of cereal crops from Pakistan. The results of dietary and toxicity exposure of PCN warrant auxiliary devotion in future, to this group of contaminant.

The toxicological effects of halogenated naphthalenes: a review of aryl hydrocarbon receptor-mediated (dioxin-like) relative potency factors

There is no doubt that chloronaphthalenes (PCNs) and their brominated counterparts (PBNs) are dioxin-like compounds, but there is less evidence for mixed bromo/chloronaphthalenes (PXNs). In this article we review information relating to the dioxin-like potency of PCNs and PBNs obtained in vivo, in vitro, and in silico. The aim was to help and improve the quality of data when assessing the contribution of these compounds in the risk analysis of dioxin-like contaminants in foods and other sample types. In vivo and in vitro studies have demonstrated that PCN/PBN congeners are inducers of aryl hydrocarbon hydroxylase, ethoxyresorufin O-deethylase, and luciferase enzymes that are features specifically indicative of planar diaromatic halogenated hydrocarbons such as dioxin and dioxin-like compounds. PCNs in the environment are of multisource origin. The limited data on PBNs in the environment suggest that these also appear to originate from different sources. The toxicological data on these compounds is even scarcer, most of it directed toward explaining the exposure risk from accidental contamination of feed with the commercial PBN containing product, Firemaster BP-6. The occurrence of PBNs and PXNs is possible as ultra-trace environmental and food-chain contaminants produced at least from combustion processes at unknown concentrations. Available toxicological and environmental data enable a focus on PCNs as dioxin analogues to an extent that specific local or regional environmental influences could result in a risk to human health. There is the possibility that they may act synergistically with the better-known classic dioxin and other dioxin-like compounds. PBNs and PXNs are much less studied than the dioxins, but are known to be products of anthropogenic processes that contaminate the environment. A continuously increasing use of bromine for manufacture of brominated flame retardants over the past three decades is anticipated as a stream of "brominated" wastes, that when degraded (combusted), will release PBNs and PXNs. This calls for advanced analytical methods and greater interest toxicologically to understand and control pollution and exposure by PBNs and PXNs. Particular congeners of bromonaphthalene in single studies were found to be much more toxic than their chlorinated counterparts. In addition, brominated/chlorinated naphthalenes also seem to be more potent toxicants than PCNs. About 20% of PCN congeners exhibit a dioxin-like toxicity with relative potencies varying between around 0.003 and 0.000001, but additional and more rigorous data are needed to confirm these figures. Recent food surveys have estimated a small but relevant human exposure to these compounds in foods, giving an additional source of dioxin-like toxicity to those compounds already covered by the World Health Organization-Toxic Equivalency Factors (TEFs) scheme. Given the additivity of response postulated for other dioxin-like compounds, it would seem unwise to ignore this additional contribution. Few data available showed that PBN congeners also exhibit a dioxin-like toxicity and are even more potent than PCN congeners, but the relative potency values were not derived for them until now. There are no toxicological data available for PXNs.

Sources of unintentionally produced polychlorinated naphthalenes

The European Union has proposed that polychlorinated naphthalenes (PCNs) should be included in the annexes of the Stockholm Convention on Persistent Organic Pollutants, signifying that there will be an increase in activities aimed at reducing PCN emissions. It has been speculated that the unintentional formation and emission of PCNs from industrial activities are the main current sources, because they have ceased to be manufactured as industrial chemicals in many countries. In this review, we provide a brief overview of recent progress in research into the unintentional formation and emission of PCNs from various industries that use thermal processes. The sampling and analysis of PCNs, and their formation mechanisms during thermal processes, are reviewed and discussed. The emission levels, emission profiles, and emission factors of PCNs from a number of industries that use thermal processes are summarized and compared, and this will provide helpful information for planning PCN source control measures and studying the source-receptor relationships of PCNs.

Degradation of polychlorinated naphthalene by mechanochemical treatment

Polychlorinated naphthalene (PCN) is a hazardous compound that is listed as a new persistent organic pollutants candidate by the United Nations Environment Program. The production, import and use of PCNs are prohibited by the Chemical Substances Control Law in Japan. PCN was milled with calcium oxide as an additive to investigate the feasibility of its degradation by mechanochemical treatment. The milling process cleaved the C-C and C-Cl bonds by the mechanically induced solid-state reaction. Gas chromatography/mass spectrometry analysis confirmed that the PCN was decomposed after 1h milling. The yield of chloride ions reached 100% after 3h milling. This indicates that all PCN was broken down into inorganic compounds after milling, thereby maintaining the chlorine mass balance through the reaction. This experiment, for the first time, exhibited the effectiveness of mechanochemical treatment as a PCN degradation method.

Determination of indicator polychlorinated biphenyls (PCBs) by gas chromatography-electron capture detector

An effective method for determination of indicator polychlorinated biphenyls (PCBs) has been validated using gas chromatography (GC) equipped with electron capture detector (ECD). The GC-ECD method was validated by determining the linear range (working range) for determination of the compounds, minimum detectable quantities (MDQ), the precision and accuracy of the method for the analysis of the compounds. MDQ obtained for the compounds ranges from 0.0005 to 0.002 ng. Indeed the method was found to be more sensitive as the number of chlorine atoms attached to the biphenyl increases. The precision and accuracy of the GC method validated ranges from 2.4% to 14.5% and -7.0% to 14.6% respectively. Coefficient of variation associated with the repeatability of the retention times and corresponding peak areas was found to be 0.0001-0.0007 for the retention times and 0.0014-0.059 for the peak areas. Percentage recoveries for the compounds were in the range of 95.7-101.0%. The validated method was then applied to determine levels of indicator PCBs in sediments sampled from eleven sampling points along the Lake Bosuntwi in Ghana and the highest PCB load of 19.17 ng g(-1) was recorded at Pipie No. 2. PCB 52 and PCB 101 were found to be the most ubiquitous indicator PCBs in the study area, both with 90.91% occurrence.

Characterization of polychlorinated naphthalenes in stack gas emissions from waste incinerators

Nine typical waste incinerating plants were investigated for polychlorinated naphthalene (PCN) contents in their stack gas. The incinerators investigated include those used to incinerate municipal solid, aviation, medical, and hazardous wastes including those encountered in cement kilns. PCNs were qualified and quantified by isotope dilution high resolution gas chromatography-high resolution mass spectrometry techniques. An unexpectedly high concentration of PCNs (13,000 ng Nm(-3)) was found in the stack gas emitted from one waste incinerator. The PCN concentrations ranged from 97.6 to 874 ng Nm(-3) in the other waste incinerators. The PCN profiles were dominated by lower chlorinated homologues, with mono- to tetra-CNs being the main homologues present. Furthermore, the relationships between PCNs and other unintentional persistent organic pollutants involving polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, hexachlorobenzene, and pentachlorobenzene were examined to ascertain the closeness or otherwise of their formation mechanisms. A good correlation was observed between ΣPCN (tetra- to octa-CN) and ΣPCDF (tetra- to octa-CDF) concentrations suggesting that a close relationship may exist between their formation mechanisms. The results would provide an improved understanding of PCN emissions from waste incinerators.

Altitudinal distributions of PCDD/Fs, dioxin-like PCBs and PCNs in soil and yak samples from Wolong high mountain area, eastern Tibet-Qinghai Plateau, China

Topsoil along the altitudinal gradient (2086-4487 m above sea level) and yak samples, collected from Wolong high mountain area of Sichuan Province, western China, were analyzed for polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs) and polychlorinated naphthalenes (PCNs) using HRGC-HRMS. The total concentrations of PCDD/Fs, dl-PCBs, and PCNs in soils were: 2.48-4.30 pg g(-1) dw (dry weight), 7.6-10.5 pg g(-1) dw, and 13.0-29.0 pg g(-1) dw, respectively; the greatest concentrations were found at sampling sites of 3,927 m, 4487 m and 3,345 m, correspondingly. The total PCDD/Fs and dl-PCBs concentrations showed positive correlations with increasing altitudinal gradient. The congener profiles of both 2,3,7,8-PCDD/Fs and dl-PCBs at different altitudes showed similar patterns. PCNs were dominated by Tri-CNs. The long-range atmospheric transport and subsequent aerial deposition are likely the sources for these POPs in area examined. The total TEQs in soils were in the range of 0.28-0.42 pg g(-1) dw, and the total TEQs in the yak muscle and fatty tissue samples were 3.81-4.09 pg TEQ g(-1) lipid weight. The daily intake of TEQs was estimated to be below the WHO's tolerable daily intake according to the local people's dietary habits in Wolong area, which is unlikely to cause any adverse health effects to the yak muscle consuming people.

Comparison of historical record of PCDD/Fs, dioxin-like PCBs, and PCNs in sediment cores from Jiaozhou Bay and coastal Yellow Sea: implication of different sources

The concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs) were measured in two sediment cores collected from Jiaozhou Bay. The concentrations of PCDD/Fs, dioxin-like PCBs, and PCNs in the cores were in the range of 2.8-26.3, 7.1-82.4 and 3.9-56.4 pg/g dw, respectively. The depth profiles of total concentrations PCDD/Fs and dioxin-like PCBs were similar in the sediment core J37 inside Jiaozhou Bay, but different from those in the sediment core J94 outside the bay, suggesting the different sources. In both cores Tri-CNs and Tetra-CNs were dominant, similar to the PCNs composition of some Halowax technical products. The maximal PCNs contamination occurred in the mid-1970s (outside the Bay) and early-1990s (inside the Bay). An increase of the indicator CN congeners characteristic for thermal source in the top layers of the sediment core inside the bay indicated that the contribution from the municipal solid waste incineration has been more important in recent years.

Polychlorinated naphthalenes (PCNs) in the surface soils of the Pearl River Delta, South China: distribution, sources, and air-soil exchange

Polychlorinated naphthalenes (PCNs) are now under review by the Stockholm Convention as a candidate for POPs for their persistence, toxicity, bioaccumulation, and long-range atmospheric transport. Data regarding PCN levels and their environmental fate are sparse in China. The PCN concentration and distribution in soils of the Pearl River Delta were reported, and the average total concentration was 59.9 ± 86.7 pg/g. Tri-CNs was the dominant homologue group, and CN 24 was the most abundant congener. A gradient of PCN levels between more and less developed areas was observed. Based on fugacity fraction results, CN 51 is proposed as a possible source marker for specific combustion emissions. Air-soil exchange of PCNs was estimated by calculating the soil and air fugacity. Fugacity fraction values indicated that tri- to penta-CNs were closer to equilibrium in winter and toward net volatilization in summer, while hexa-CNs experienced net air-to-soil transfer in both seasons.

Atmospheric emission of polychlorinated naphthalenes from iron ore sintering processes

Iron ore sintering processes constitute significant sources of dioxins, and studies have confirmed a close correlation between polychlorinated naphthalenes (PCNs) and dioxin formation. Thus, iron ore sintering processes are thought to be a potential source of PCNs, although intensive investigations on PCN emissions from sintering processes have not been carried out. Therefore, the aim of the present study was to qualify and quantify PCN emissions from nine sintering plants operating on different industrial scales. PCN concentrations ranged from 3 to 983 ng m(-3) (0.4-23.3 pg TEQ(PCN) m(-3)) and emission factors ranged from 14 to 1749 μg t(-1) (0.5-41.5 ng TEQ(PCN) t(-1)), with a geometric mean of 84 μg t(-1) (2.1 ng TEQ(PCN) t(-1)). The estimated annual emission of PCNs from sintering processes in China was 1390 mg TEQ(PCN). These figures will assist in the development of a PCN emissions inventory. Regarding emission characteristics, PCNs mainly comprised low-chlorinated homologs. The ratios of several characteristic PCN congeners were also measured and compared with those from other sources. Taken together, these results may provide useful information for identifying the sources of PCNs produced by iron ore sintering processes.

Mixed poly-brominated/chlorinated biphenyls (PXBs): widespread food and environmental contaminants

Mixed poly-brominated/chlorinated biphenyls (PXBs) are a new class of emerging contaminants. Their environmental occurrence is confirmed by the reported occurrence in foods and human tissues, and the patterns of occurrence suggest that different sources may be contributing to food occurrence in different parts of the world. Important sources of PXBs are thought to include emissions from the combustion of bromine and chlorine containing waste and consumer products and inadvertent contamination in industrial chemicals. Of specific interest are the dioxin-like-PXBs. These are the 62 non-ortho-substituted PXBs with eight congeners of 3,3',4,4'-substitution type (#77A-H), ten of 3,4,4',5-type (#81A-J), twenty four of 3,4,5,3',4'-type (#126A-Z) and twenty of 3,4,5,3',4',5'-type (#169A-V) and many mono-ortho substituted compounds. The toxicological clarification on these contaminants continues, with reports confirming dioxin-like effects at low concentrations, suggesting a greater toxicological significance than PCBs.

Comparison of organohalogen compounds in a white-tailed sea eagle egg laid in 1941 with five eggs from 1996 to 2001

Eggs laid by white-tailed sea eagles (Haliaeetus albicilla), one in 1941 and five eggs between 1996 and 2001, all from the same geographical region of the Baltic Sea, were screened for organohalogen substances. The 1941 egg contained hexachlorobenzene (HCB), but did not contain either of the pesticides hexachlorocyclohexane (HCH) or p,p'-DDT, nor any metabolites of the latter. In contrast, the more recent eggs (REs) contained all of these compounds. Of the seven polychlorinated biphenyls (PCBs) analyzed (CB28, -52, -101, -118, -138/-163, -153 and 180), only the more highly chlorinated congeners were detected in the 1941 sample, with CB153 followed by CB180 showing the highest concentrations. All eggs demonstrated the same congener pattern with respect to the more highly chlorinated PCBs, but concentrations were approximately 70-230 times higher in the REs. All of the polychlorinated-p-dioxin and dibenzofuran (PCDD/Fs) congeners analyzed were detected in the eggs, with the dominant congener being 2,3,4,7,8-PeCDF (1250pg/gl.w. in 1941 and 1540pg/gl.w. (GM) for the REs, respectively). None of the other congeners exceeded 400pg/gl.w., and the concentrations of 2,3,7,8-TCDD, 2,3,7,8-TCDF and 1,2,3,7,8-PeCDF were all lower in the REs. None of five congeners of polybrominated diphenyl ethers (PBDEs) found in the REs was detected in the egg from 1941. The three methoxylated brominated diphenyl ethers (MeO-BDEs) analyzed were found at similar levels and with a similar congener pattern in REs as in the egg from 1941. In conclusion, this study has shown the absence of DDE and PBDE and the presence of HCB and PCBs in a white-tailed sea eagle egg laid in 1941, and a strong increase of PCBs, DDE and PBDE in white-tailed sea eagle eggs from the same area in 1996-2001. The MeO-BDEs were found in similar concentrations in the analyzed eggs. The 1941 sample shows substantial concentrations of PCDD/Fs, noteworthy in the same magnitude as in the recent samples, illustrating the historical and recent exposure of these compounds.

Atmospheric polychlorinated naphthalenes in Ghana

A nationwide monitoring of atmospheric POPs (persistent organic pollutants) was conducted in Ghana between May and July 2010, applying polyurethane foam (PUF) disk passive air samplers (PAS). Reported here are preliminary findings on PCNs, an industrial organic contaminant currently under review for possible listing under the global chemical treaty. The present results constitute the first set of nationwide data on air PCNs from a West African country. Contrary to expectation, air PCNs levels were quite high in Ghana, at an average of 49 ± 5.4 pg/m(3). The coastal (southern) zone of Ghana appeared the most impacted, with crude open burning of waste, industrial emissions, and the harbor environment identified among possible emission factors. Tri- and tetra-CNs (the lowly chlorinated homologues) predominated in the atmosphere, altogether constituting approximately 90% of total PCN homologues composition. Increased volatilization under tropical conditions was presumed a key factor that contributed to this high atmospheric input of lowly chlorinated homologues. We further observed a significant level of fractionation of PCN homologues across the breadth of the country. The percentage composition of the lowly chlorinated homologues increased northwards, probably because of their transportation in the direction of prevailing winds. From congener profile analysis, PCN-45/36 is proposed as a possible source marker for emissions preempted by uncontrolled waste burning activities. Dioxin-like toxicity of air PCNs in Ghana was estimated to range 0.49-5.6 fg TEQ/m(3). This study brought to the fore the emerging problems of nonagricultural organohalogens that covertly might be confronting the environment in African nations like Ghana.

Behavioral effects following repeated exposure to hexachloronaphthalene in rats

Polychlorinated naphthalenes (PCNs), including hexachloronaphthalene (HxCN), are widespread global environmental contaminants. Our experiments were aimed at assessing HxCN effects on motor behavior, long-term memory, pain sensitivity, magnitude of stress-induced analgesia, auditory function and sensorimotor gating, following repeated intragastric administration (28 days) of HxCN at 0.3 and 1.0 mg/kg body weight. Three weeks after the exposure termination, male Wistar rats were subjected to the neurobehavioral tests battery performed in the following order: open-field test, passive avoidance test, hot-plate test and acoustic startle response test. Repeated administration of HxCN induced disorders of motivational processes manifested by: anorectic effect caused by aphagia and adipsia; significantly reduced motor activity (hypokinesia); impaired long-term memory and acquired passive avoidance reaction; reduced pain threshold and shortened duration of anxiety reaction after pain stimulus (sensory neglect). Some of these neurobehavioral effects (impaired long-term memory, reduced pain threshold and stress-induced analgesia) were observed at 0.3 mgHxCN/kg body weight without any signs of overt toxicity. The outcome of our study shows that HxCN, like other compounds of the persistent organic pollutants (POPs) group, creates a potential risk of behavioral changes in the central nervous system in the general population as a result of environmental exposure.

Passive air monitoring of PCBs and PCNs across East Asia: a comprehensive congener evaluation for source characterization

A comprehensive congener specific evaluation of polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in the atmosphere was conducted across East Asia in spring 2008, applying polyurethane foam (PUF) disk passive air sampler (PAS) as monitoring device. Mean concentrations derived for Japan, China and Korea were 184 ± 24, 1100 ± 118, and 156 ± 20 pg m(-3) for ∑(202) PCBs, and 9.5 ± 1.5, 61 ± 6, and 16 ± 2.4 pg m(-3) for ∑(63) PCNs, respectively. Relative to reported data from 2004, the present results suggest that air PCBs concentrations have not changed much in Japan and Korea, while it has increased by one order of magnitude in China. From principal component analysis, combustion emerged highly culpable in contemporary emissions of both PCBs and PCNs across the East Asian sub-region. Another factor derived as important to air PCBs was re-emissions/volatilization. Signals from PCBs formulations were also picked, but their general importance was virtually consigned to the re-emissions/volatilization tendencies. On the contrary, counterpart PCNs formulations did not appear to contribute much to air PCNs.

Polychlorinated naphthalenes (PCNs) in riverine and marine sediments of the Laizhou Bay area, North China

PCN congeners were analyzed in marine and riverine sediments of the Laizhou Bay area, North China. Concentrations of PCNs ranged from 0.12 to 5.1 ng g(-)(1) dry weight (dw) with a mean value of 1.1 ng g(-)(1) dw. The levels of PCNs varied largely, with industrial group approximately ten folds higher than those of the rural in riverine sediment. A strong impact by direct discharge from local factories was suggested. Similar compositional profiles were found within groups. High resemblance of compositional profiles between industrial samples and Halowax 1014 was observed. It was indicated that PCNs in riverine sediments were mainly from release of industrial usage, with additional contributions from industrial thermal process at certain sites. In marine sediments, it was suggested that PCNs along the coast of Laizhou Bay were mainly controlled by riverine input. While in the central bay, PCN distributions were possibly impacted by combined multiple factors.

Dioxin-like compounds in sediments from the Daliao River Estuary of Bohai Sea: distribution and their influencing factors

The concentrations, compositional profiles, and potential ecological risk of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in sediments of the Daliao River Estuary were investigated. Total concentrations of PCDD/Fs, PCBs, and PCNs were in the range of 11.3-133.2 ng/kg dry weight (dw), 1 971-37 632 ng/kg dw and 33.1-284.4ng/kg dw, respectively. The total TEQ values varied from 0.37 to 4.08ng/kg dw, with the dominant contributions by PCDD/Fs, then by PCBs and PCNs. The spatial distributions of PCDD/Fs, PCBs and PCNs in the river estuary were much related to hydrodynamic conditions. The risk of contamination to the deeper sea was increased in the flood seasons. Moreover, our data confirmed that both organic matter in sediments and molecular properties of dioxin-like compounds were the factors which strongly influenced the partition behavior of these dioxin-like compounds between sediments and water phase in the estuarine zone.

Review of 'emerging' organic contaminants in biosolids and assessment of international research priorities for the agricultural use of biosolids

A broad spectrum of organic chemicals is essential to modern society. Once discharged from industrial, domestic and urban sources into the urban wastewater collection system they may transfer to the residual solids during wastewater treatment and assessment of their significance and implications for beneficial recycling of the treated sewage sludge biosolids is required. Research on organic contaminants (OCs) in biosolids has been undertaken for over thirty years and the increasing body of evidence demonstrates that the majority of compounds studied do not place human health at risk when biosolids are recycled to farmland. However, there are 143,000 chemicals registered in the European Union for industrial use and all could be potentially found in biosolids. Therefore, a literature review of 'emerging' OCs in biosolids has been conducted for a selection of chemicals of potential concern for land application based upon human toxicity, evidence of adverse effects on the environment and endocrine disruption. To identify monitoring and research priorities the selected chemicals were ranked using an assessment matrix approach. Compounds were evaluated based upon environmental persistence, human toxicity, evidence of bioaccumulation in humans and the environment, evidence of ecotoxicity and the number and quality of studies focussed on the contaminant internationally. The identified chemicals of concern were ranked in decreasing order of priority: perfluorinated chemicals (PFOS, PFOA); polychlorinated alkanes (PCAs), polychlorinated naphthalenes (PCNs); organotins (OTs), polybrominated diphenyl ethers (PBDEs), triclosan (TCS), triclocarban (TCC); benzothiazoles; antibiotics and pharmaceuticals; synthetic musks; bisphenol A, quaternary ammonium compounds (QACs), steroids; phthalate acid esters (PAEs) and polydimethylsiloxanes (PDMSs). A number of issues were identified and recommendations for the prioritisation of further research and monitoring of 'emerging' OCs for the agricultural use of biosolids are provided. In particular, a number of 'emerging' OCs (PFOS, PFOA and PCAs) were identified for priority attention that are environmentally persistent and potentially toxic with unique chemical properties, or are present in large concentrations in sludge, that make it theoretically possible for them to enter human and ecological food-chains from biosolids-amended soil.

Estimation and characterization of polychlorinated naphthalene emission from coking industries

Occurrence of polycyclic aromatic hydrocarbons (PAHs) during the coking process has been widely recognized. The formation of polychlorinated naphthalenes (PCNs) from PAHs during some thermal related processes has been confirmed in many studies. Thus, the coking process is assumed to be a potential source of PCNs. However, intensive investigations on PCN emissions during the coking process are lacking. In order to evaluate PCN emissions from the coking process, an intensive study comprising 11 typical coke plants was undertaken. PCNs were qualified and quantified by isotope dilution HRGC/HRMS techniques. The concentrations of PCNs in stack gas samples collected from the investigated coke plants were in the range of 1.6-91.8 ng Nm(-3) (0.08-4.23 pg TEQ Nm(-3)). The emission factors of PCNs were found to be in the range of 0.77-1.24 ng TEQ per ton of coke production. The estimated annual toxic emissions of PCNs from the global coking industry vary from 430 to 692 mg TEQs. Characteristics of the PCN profiles were dominated by the lower chlorinated homologues, with mono-CN being the most abundant homologue. According to the PCN distribution and correlations of PCN homologues, it was speculated that chlorination is possibly the dominant pathway of PCN formation during the coking process.

Polychlorinated naphthalenes in polar environments--a review

Polychlorinated naphthalenes (PCNs) consist of naphthalene substituted with 1-8 chlorines, yielding 75 possible congeners. They were formerly used in industry, occur at trace levels in commercial PCB mixtures, and have current sources in combustion processes. PCNs are widespread in arctic air with higher levels in the European Arctic. Concentrations were higher during the cold months in arctic Canada and Russia, but no seasonality was noted in subarctic Canada and Greenland. "Marker" congeners indicative of combustion were evident at some sites. Total toxic equivalents (TEQ) in air due to PCNs+dioxin-like PCBs were dominated by PCNs in arctic Canada and Russia, but not in subarctic Canada. Deposition of PCNs in snow was measured in northern Norway and Svalbard. Surveys of PCNs in the lower food web are limited to the northern Baltic Sea and lakes/rivers of northern Scandinavia. PCNs showed little or no biomagnification in lower food webs of the northern Baltic and discrimination among congeners suggested preferential metabolism. There are no reports of PCNs in fish and invertebrates from the Arctic Ocean, and only one from Antarctica. Total PCNs in marine mammals followed the order: harbour seal~pilot whale>or=polarbear>beluga>ringed seal~Weddell seal. Total PCNs in seabirds varied over 100-fold, with higher concentrations in glaucous gull eggs and plasma from Bear Island, and livers of northern fulmar from the eastern Canadian Arctic. Lower concentrations occurred in eggs of glaucous gull from Svalbard and black-backed gull from the Faroe Islands. PCNs accounted for <1% of total TEQ in ringed seal, Weddell seal, seabirds and polar bear, but up to 6-15% in beluga and pilot whale. TEQ due to PCNs were generally low in harbour seal, but up to 9% of total TEQ in some animals.

The analysis of dioxins and related compounds

The analysis of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, polychlorinated biphenyls, and other related compounds requires complex sample preparation and analytical procedures using highly sensitive and selective state-of-the-art instrumentation to meet very stringent data quality objectives. The analytical procedures (extraction, sample preparation), instrumentation (chromatographic separation and detection by mass spectrometry) and screening techniques for the determination of dioxins, furans, dioxin-like polychlorinated biphenyls and related compounds with a focus on new approaches and alternate techniques to standard regulatory methods are reviewed.

Relative importance of polychlorinated naphthalenes compared to dioxins, and polychlorinated biphenyls in human serum from Korea: contribution to TEQs and potential sources

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in human have been studied extensively; however, polychlorinated naphthalenes (PCNs) have been studied less widely. The mean concentrations of PCNs, PCDDs, PCDFs, and PCBs in 61 healthy human volunteers were 2170 pg/g lipid, 452 pg/g lipid, 116 pg/g lipid, and 120 ng/g lipid respectively, and the mean toxic equivalents (TEQs) contributed by PCNs, PCDDs, PCDFs, and PCBs were 5.88, 5.22, 5.48, and 5.33 pg/g lipid, respectively. PCNs contributed to 26.8% of the total TEQs. 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF, PCB126, and hepta-CN-73 accounted for >62% of the total TEQs in the human serum samples. The overall serum PCN homologue profiles of all subjects were dominated by tetra- and penta-CN homologues, and the most predominant individual congener was hepta-CN-73, which contributed 17.5% of the total serum PCN concentration. Enrichment of hepta-CN-73 in the human serum samples might be due to contributors from combustion sources.

Polychlorinated naphthalenes (PCNs): congener specific analysis, occurrence in food, and dietary exposure in the UK

Information on the occurrence of toxicologically significant polychlorinated naphthalenes (PCNs) in food, or on human exposure, is sparse. In this work, PCN congeners (PCNs 52, 53, 66/67, 68, 69, 71/72, 73, 74, and 75) were selected for analysis, based on the available literature on current occurrence and toxicology, and limited by the commercial availability of reference standards. The analytical methodology used cold solvent extraction of prehydrolyzed samples fortified with internal standards ((13)C(10) labeled PCNs), activated carbon and basic alumina purification, and measurement by HRGC-HRMS. The investigation showed PCN occurrence in all studied foods: meat, milk, fish, dairy and meat products, eggs, poultry, vegetables, fruits, etc. The most frequently detected congeners were PCN 52, PCNs 66/67, and PCN 73. The highest concentrations were observed in fish (maximum value of 37 ng/kg w.w. for the sum of the measured congeners). The dioxin-like toxicity (PCN TEQ) associated with these concentrations is 1-2 orders of magnitude lower than those reported for chlorinated dioxins or PCBs in food and, on the basis of dietary intakes estimated using very conservative assumptions regarding concentrations of these contaminants in the UK, the levels of PCNs alone in food do not suggest any toxicological concerns.

Estimation and congener-specific characterization of polychlorinated naphthalene emissions from secondary nonferrous metallurgical facilities in China

Secondary nonferrous production is addressed as one of the potential sources of the unintentionally produced persistent organic pollutants (UP-POPs) due to the impurity of raw material. Although there are inventories of dioxin emissions from secondary nonferrous metallurgical facilities, release inventories of polychlorinated naphthalenes (PCNs) are scarce. This study selected typical secondary copper, aluminum, zinc, and lead plants to investigate the emissions of PCNs in secondary nonferrous production in China. The toxic equivalency (TEQ) emission factor for PCNs released to the environment is highest for secondary copper production, at 428.4 ng TEQ t(-1), followed by secondary aluminum, zinc, and lead production, at 142.8, 125.7, and 20.1 ng TEQ t(-1), respectively. PCNs released in secondary copper, aluminum, lead, and zinc production in China are estimated to be 0.86, 0.39, 0.009, and 0.01 g TEQ a(-1), respectively. Analysis of stack gas emission from secondary nonferrous production revealed that less-chlorinated PCNs are the dominant homologues, with mono- to tri-CNs making the most important contributions to the concentration. However, for fly ash, the more highly chlorinated PCNs such as octa-CN are the dominant homologues.

Polybrominated diphenyl ethers, polychlorinated naphthalenes and polycyclic musks in human fat from Italy: comparison to polychlorinated biphenyls and organochlorine pesticides

Prior to this study, reports of occurrence of polycyclic musks and polychlorinated naphthalenes (PCNs) in human tissues from Italy were not available. In this study, concentrations of PCNs and polycyclic musks were determined in human adipose tissue from Italy collected during 2005-2006; for comparison, legacy organohalogen pollutants such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined. SigmaPCN concentrations ranged from 0.5 to 14 ng/g lipid wt (lw). Polycyclic musks such as HHCB and AHTN were found in 92% and 83% of the human samples, respectively. Concentrations of PBDEs in Italian adipose tissue ranged between 3.2 and 35.6 ng/g lw.

Toxicity of hexachloronaphthalene (HxCN) and induction of CYP 1A in rats

The aim of the study was to investigate the toxicity of hexachloronaphthalene (HxCN) and its effect on cytochrome P-450 in rats and to make a comparison between HxCN and tetrachloronaphthalene (TeCN), an inactive congener. Our study provided evidence that the anorectic effect, with concurrent significant increase in relative liver mass was the most spectacular symptom of the toxic effect of hexachloronaphthalene in the rats after its single (250mg/kg) and repeated (1 and 10mg/kg) administration. Regardless of the kind of the experiment (acute or subacute toxicity), dose-dependent increase in lipid peroxidation in the liver was also observed, which may indicate that HxCN most probably generates oxidative stress in this organ. It was also observed that HxCN is a very strong inducer of cytochrome P-450, especially of CYP 1A, which is the most sensitive biomarker of exposure to this congener. In this study, LOAEL is 1mg HxCN/kgb.w.

Prediction of gas-phase thermodynamic properties for polychlorinated naphthalenes using G3X model chemistry and density functional theory

The standard gas-phase enthalpies of formation of polychlorinated naphthalenes (PCNs) have been predicted using G3X model chemistry, density functional theory (DFT), and second-order Muller-Plesset (MP2) theory. Two isodesmic reactions are used for better prediction of formation enthalpies. The first (IR1) employs chlorobenzene as a reference species and the second (IR2) employs polychlorinated benzenes as reference species. Among congeners, PCNs with simultaneous Cl-substitutions at positions 1 and 8 or 4 and 5 are the least stable, where the strong repulsion between Cl-atoms leads to non-planar structures for a few PCNs. The potential energy curves for ring-wagging motions in 1,8- or 4,5-PCNs are also extremely flat in the vicinity of equilibrium conformations, leading to extremely low harmonic frequencies for the ring-wagging modes. The contributions of these ring-wagging modes to entropy, heat capacity, and thermal corrections have been calculated using the numerically evaluated energy levels. The PCN isomer patterns are discussed based on the calculated Gibbs free energies.

Fungal hydroxylation of polychlorinated naphthalenes with chlorine migration by wood rotting fungi

Biodegradation of the polychlorinated naphthalenes (PCNs) 1,4-dichloronaphthalene (1,4-DCN), 2,7-dichloronaphthalene (2,7-DCN), and 1,2,3,4-tetrachloronaphthalene (1,2,3,4-TCN), by the white-rot fungus Phlebia lindtneri was investigated. 1,4-DCN was metabolized to form six metabolites by the fungus. It was estimated from GC-MS fragment patterns that the metabolites were four putative hydroxylated and two dihydrodihydroxylated compounds. One of the hydroxylated products was identified as 2,4-dichloro-1-naphthol by GC-MS analysis using an authentic standard. This intermediate indicated chlorine migration in a biological system of P. lindtneri. 2,7-DCN was metabolized to five hydroxylated metabolites and a dihydrodihydroxylated metabolite. Significant inhibition of the degradation of DCNs and formation of their metabolic products was observed in incubation with the cytochrome P-450 monooxygenase inhibitor piperonyl butoxide. The formation of the dihydrodiol-like metabolites, chlorine migration and the experiment with P-450 inhibitor suggested that P. lindtneri provides hydroxyl metabolites via benzene oxide intermediates of DCNs by a cytochrome P450 monooxygenase. In addition, P. lindtneri degraded 1,2,3,4-TCN; two hydroxylated compounds and a dihydrodihydroxylated compound were formed.

Distribution profiles of selected organic pollutants in soils and sediments of industrial, residential and agricultural areas of South Africa

Currently very little data exists on the presence of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in the South African environment. To address this data gap a preliminary study of a highly industrialised area of South Africa, the Vaal Triangle, was done. Soil and sediment samples from the Vaal Triangle, as well as other areas in central South Africa, were analysed with high resolution gas chromatography-high resolution mass spectrometry (HRGC/HRMS) for the presence of PAHs, polychlorinated biphenyls (PCBs), dioxin-like chemicals and organochlorine pesticides (OCPs). Results showed that these chemicals are present in the South African environment with concentrations ranging between 39,000 ng g(-1) for SigmaPAHs and 0.01 ng g(-1) for dicofol. Principal component analysis (PCA) indicated different pollution sources in industrial and agricultural areas.

Dioxin-like compound compositional profiles of furnace bottom ashes from household combustion in Poland and their possible associations with contamination status of agricultural soil and pine needles

A compositional profile of PCDDs, PCDFs, non- and mono-ortho PCBs, and PCNs of several type furnace bottom ashes obtained after the heating muffle stove for domestic use combustion of hard coal, coke, wood, and solid domestic waste mixture have been examined as possible contributors to environmental diffusion with these compounds in Poland. The uppermost concentration of dioxin-like compounds with 2.0 ng TEQ kg(-1) dry weight found for wood ash was dominated by PCDDs and PCDFs, while for other types of ashes were in the range from 0.052 ng TEQ kg(-1) to 0.67 ng TEQ kg(-1) dry weight. The multivariate statistical analysis displayed some compositional similarity of PCDDs, PCDFs and PCNs between the ashes and environmental pine needle or agricultural soil matrices collected in Poland.

PCNs, PCDD/Fs, and non-orthoPCBs, in water and bottom sediments from the industrialized Norwegian Grenlandsfjords

Chlorinated toxic planar aromatic compounds were analyzed in the heavily industrialized Grenlandsfjords, which is a system of silled fjords in southern Norway. Surface water samples contained 7.4-160 ng/m3 polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), 14-410 ng/m3 polychlorinated naphthalenes (PCNs), and 0.31-2.4 ng/m3 non-orthochlorinated biphenyls (non-orthoPCBs). The concentrations of PCDD/Fs were about 300 times higher than in the Baltic Sea. Highest level of the compounds wasfound near a magnesium production plant Hepta-CDFs and penta-CNs dominated in the inner-fjord waters, and tetra-CB 77 was the major non-orthoPCB congener. Sediment samples had PCDD/F concentration of 25-730 ng/g dw. Highest concentration was detected close to the magnesium plant. Octa-CDFdominated in the fjord sediments, especially near the magnesium plant indicating a discharge-specific contamination with this congener. The isomer composition of PCDD/Fs and of PCNs, was unchanged when comparing samples from different layers of a sediment core from the deep anoxic water. This concludes that essentially zero degradation had occurred during approximately 50 years in this environment.

Airborne chloronaphthalenes in Scots pine needles of Poland

The amounts, profiles and origin of CNs (from triCNs to octaCN) sequestered in Scots pine needles collected from 25 spatially distant sites in Poland have been studied based on congener-specific data obtained after a several clean-up and fractionation steps and final HRGC/HRMS separation and determination. The absolute concentrations of CNs varied largely from site to site, i.e., by 15-fold. The sum of tri- to octaCN concentration at fifteen of the least contaminated sites ranged from 70 to 280 pg g(-1) ww, and at further eight sites were from 340 to 540 pg g(-1) ww, while at two the most contaminated were 1000 and 1100 pg g(-1)ww. There were some substantial similarities but also variations in triCN to octaCN homologue group profiles depending on the site. Among triCNs the isomers such as 1,2,4-/1,3,7-/1,4,6-triCNs (nos. 14/21/24) dominate in Scots pine needles. For majority of the sites examined 1,2,4-/1,3,7-/1,4,6-triCNs are also the major contributors to the bulk of CNs determined. Among tetraCNs isomer 1,2,5,8-tetraCN (no. 38) was dominant contributor at eighteen sites, while 1,2,4,6-/1,2,4,7-/1,2,5,7-tetraCN (nos. 33/34/37) at seven other sites. In the case of pentaCNs isomer 1,2,4,5,8-pentaCN (no. 59), was dominant contributor alone. Octachloronaphthalene frequently contributed substantially to the bulk of CNs. The Cluster Analysis and Principal Component Analysis did indicate that the compositional profiles of CNs found in Scots pine needles resemble somehow these found in the bottom ashes after coke and coal burning as well as of Halowax 1000 and 1099 formulations.

Relative potencies of individual chlorinated and brominated polycyclic aromatic hydrocarbons for induction of aryl hydrocarbon receptor-mediated responses

Chlorinated and brominated polycyclic aromatic hydrocarbons (CIPAHs and BrPAHs) occur as pollutants in the environment. Nevertheless, there is little information available regarding the toxic effects of CIPAHs and BrPAHs. The potencies of 19 individual ClPAHs and 11 individual BrPAHs to induce aryl hydrocarbon receptor (AhR)-mediated activities (i.e., dioxin-like toxicity), relative to the potency of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), were determined in vitro by use of a recombinant rat hepatoma cell (H4IIE-luc) assay. Several CIPAHs elicited AhR-mediated activity; the relative potencies (RePs) of 6-monochlorochrysene, and 7-monochlorobenz[a]anthracene were 2.6 x 10(-5) and 6.3 x 10(-6), respectively. Among BrPAHs, 7-monobromobenz[a]anthracene and 4,7-dibromobenz[a]anthracene had the highest RePs, 2.1 x 10(-5) and 2.3 x 10(-5), respectively. None of the chlorinated or brominated anthracene or fluorene compounds elicited AhR-mediated activity atthe concentrations tested. We developed a structure-activity relationship for AhR-mediated potencies of CIPAHs.The RePs of ClPhe and ClFlu (low-molecular-weight ClPAHs) were directly proportional to the compounds' degrees of chlorination. The RePs of higher-molecular-weight ClPAHs (> or = 4-rings) were lower than those of the corresponding parent PAHs. The RePs of BrPAHs were higher than the RePs of the corresponding ClPAHs. For instance, 6-BrBaP was more potent than 6-ClBaP and 7-BrBaA was more potent than 7-ClBaA. The RePs determined in this study were applied to literature concentrations of Cl- and Br-PAHs in environmental samples, to calculate dioxin-like toxicities, as toxic equivalents (TEQs). The TEQs of ClPAHs calculated using the concentrations of individual ClPAHs were 4.6 pg-TEQ/g in fly ash, 0.015 fg-TEQ/m3 in automobile exhaust, and 0.085 fg-TEQ/m3 in urban air. 6-ClChr accounted for 80% of the total ClPAHs-TEQs in fly ash. This is the first in vitro study to report AhR-mediated activities of Cl- and Br-PAHs relative to the activity of TCDD.

Polychlorinated naphthalenes in human adipose tissue from New York, USA

Polychlorinated naphthalenes (PCNs) are persistent, bioaccumulative, and toxic contaminants. Prior to this study, the occurrence of PCNs in human adipose tissues from the USA has not been analyzed. Here, we have measured concentrations of PCNs in human adipose tissue samples collected in New York City during 2003-2005. Concentrations of PCNs were in the range of 61-2500pg/g lipid wt. in males and 21-910pg/g lipid wt. in females. PCN congeners 52/60 (1,2,3,5,7/1,2,4,6,7) and 66/67 (1,2,3,4,6,7/1,2,3,5,6,7) were predominant, collectively accounting for 66% of the total PCN concentrations. Concentrations of PCNs in human adipose tissues were 2-3 orders of magnitude lower than the previously reported concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Concentrations of PCNs were not correlated with PCB concentrations. The contribution of PCNs to dioxin-like toxic equivalents (TEQs) in human adipose tissues was estimated to be <1% of the polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F)-TEQs.

Chlorinated and parent polycyclic aromatic hydrocarbons in environmental samples from an electronic waste recycling facility and a chemical industrial complex in China

Chlorinated polycyclic aromatic hydrocarbons (CIPAHs) are a class of halogenated contaminants found in the urban atmosphere; they have toxic potential similar to that of dioxins. Information on the sources of CIPAHs is limited. In this study, concentrations of 20 CIPAHs and 16 parent PAHs were measured in electronic wastes, workshop-floor dust, vegetation, and surface soil collected from the vicinity of an electronic waste (e-waste) recycling facility and in surface soil from a chemical industrial complex (comprising a coke-oven plant, a coal-fired power plant, and a chlor-alkali plant), and agricultural areas in central and eastern China. High concentrations of SigmaCIPAHs were found in floor dust (mean, 103 ng/g dry wt), followed in order of decreasing concentration by leaves (87.5 ng/g drywt), electronic shredder waste (59.1 ng/g dry wt), and soil (26.8 ng/g dry wt) from an e-waste recycling facility in Taizhou. The mean concentration of SigmaCIPAHs in soil from the chemical industrial complex (88 ng/g dry wt) was approximately 3-fold higher than the concentration in soil from e-waste recycling facilities. The soils from e-waste sites and industrial areas contained mean concentrations of SigmaCIPAHs 2 to 3 orders of magnitude higher than the concentrations in agricultural soils (ND-0.76 ng/g), suggesting that e-waste recycling and chlorine-chemical industries are potential emission sources of CIPAHs. The profiles of CIPAHs in soil and dust were similar to a profile that has been reported previously for fly ash from municipal solid waste incinerators (6-CIBaP was the predominant compound), but the profiles in vegetation and electronic shredder waste were different from those found in fly ash. Concentrations of 16 parent PAHs were high (150-49,700 ng/g) in samples collected from the e-waste recycling facility. Significant correlation between SigmaCIPAH and SigmaPAH concentrations suggests that direct chlorination of parent PAHs is the major pathway of formation of CIPAHs during e-waste recycling operations. Dioxin-like toxic equivalency quotients (TEQs) for CIPAHs and PAHs in samples were calculated on the basis of relative potencies reported for CIPAHs and PAHs. The highest mean TEQ concentrations of CIPAHs (518 pg-TEQ/g) were found for workshop-floor dust, followed by leaves (361 pg-TEQ/g), electronic shredder waste (308 pg-TEQ/g), soil from the chemical industrial complex (146 pg-TEQ/g), and soil from the sites of the e-waste recycling facility (92.3 pg-TEQ/g). With one exception, the floor dust samples, the TEQ concentrations of CIPAHs found in multiple environmental matrices in this study were higher than the TEQ concentrations of PCDD/Fs in the same samples reported in our earlier study.

Multivariate analysis of identity of imported technical PCN formulation

Chloronaphthalenes form a class of compounds consisting of 8 CN homologue groups and altogether of 75 congeners, which used have been most extensively in 1930--1950. An investigation have been performed on the possible origin of unidentified by name technical chloronaphthalene formulation unlawfully imported recently from the United Kingdom to Japan. Principal component analysis (PCA) and Cluster Analysis of chloronaphthalene congener isomer-specific and homologue classes' compositional HRGC/HRMS data of imported CN formulation and of certain brands of technical CN formulation called Halowax (Halowax 1000, 1001 and 1031) enabled to identify that unnamed product is not Halowax 1001. A less accurate multivariate examination based on CN homologue classes patter did indicate on large similarity between unlawfully imported technical CN formulation and Halowax 1001 (manufactured by the Koppers Ind. Co., USA), while a more accurate based on CN congeners pattern differentiated them as to of various origin mixtures. Based on chlorine content of imported CN formulation (50-52%) and its no similarity to Halowax 1001 it seems reasonable to conclude that unnamed CN mixture examined could be a sample of stockpiled Seekay wax R93.

Assessment of the spatial distribution of coplanar PCBs, PCNs, and PBDEs in a multi-industry region of South Korea using passive air samplers

Coplanar polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polybrominated diphenyl ethers (PBDEs) were sampled using polyurethane foam (PUF) disk passive air samplers (PAS) at 19 sites in a heavily industrialized region of South Korea for 6 months (January-July 2006). The levels and spatial distribution of these three chemical groups were investigated to identify potential sources and transport in the study area, which can be divided into five regions: a steel-manufacturing complex, a residential area near the steel complex, a rural area, a semi-industrial area, and a petrochemical-manufacturing complex. Air concentrations (pg x m(-3)) were estimated using an average sampling rate of 3.0 m3 x day(-1) and ranged as follows: coplanar PCBs (0.8-16), PCNs (1.7-35), and PBDEs (3.8-24). The levels of coplanar PCBs and PBDEs were found to be the highest in the steel complex, followed by the petrochemical complex and the semi-industrial area. In addition, a high level of PCNs was measured near a petrochemical-processing plant. However, the residential area near the steel complex and the rural area showed relatively low concentrations of these chemicals, suggesting that the steel and petrochemical industries are probably important sources in the study area, but these potential sources do not strongly influence the surrounding areas.

Biomagnification of organic pollutants in benthic and pelagic marine food chains from the Baltic Sea

The trophic transfer of organic pollutants with varying physical chemical properties was determined in both a pelagic and benthic food chain using delta 15N as a continuous variable for assessing trophic levels. The trophic transfer of organic pollutants through the entire food chain in terms of food chain magnification factors (FCMFs) was quantified from the slope of the regression between ln [concentration] and delta 15N. Organic pollutants with statistically significant FCMFs >1 were considered to biomagnify within the food chain, whereas those with FCMFs <1 were considered to trophically dilute. Statistically significant FCMFs >1 were found for PCB congeners and organochlorine pesticides in the Baltic food chains whereas statistically significant FCMFs <1 were found for PAHs and PCNs due to trophic dilution resulting from metabolism. FCMFs were generally greater in the pelagic food chain than in the benthic food chain. However, estimated FCMFs for the benthic food chain are likely in error, as the delta 15N method suggested a food chain structure which was not consistent with the known dietary patterns of the species. Biomagnification factors (BMFs) were additionally calculated as the ratio of the lipid normalized concentrations in the predator and prey species with adjustment for trophic level and were generally consistent with the FCMFs with BMF >1 for PCBs and organochlorines.

Formation and chlorination of polychlorinated naphthalenes (PCNs) in the post-combustion zone during MSW combustion

Non- to octa-chlorinated naphthalenes (PCNs) were analyzed in flue gas samples collected simultaneously at three different temperatures (450 degrees C, 300 degrees C and 200 degrees C, respectively) in the post-combustion zone during waste combustion experiments using a laboratory-scale fluidized-bed reactor. PCN homologue profiles in all samples were dominated by the lower chlorinated homologues (mono- to triCN), with successive reductions in abundance with each additional degree of chlorination. The isomer distribution patterns reflected ortho-directionality behavior of the first chlorine substituent, and the beta-positions, i.e. the 2,3,6,7-substitution sites, seemed to be favored for chlorination. Injection of naphthalene into the post-combustion zone resulted in increased PCN levels at 200 degrees C, demonstrating the occurrence of chlorination reactions in the post-combustion zone. However, the increases were restricted to the least-chlorinated homologue (monoCN), probably because there was insufficient residence time for further chlorination. In addition, an episode of poor combustion (manifested by high CO levels) was accompanied by extensive formation of 1,8-diCN, 1,2,3- and 1,2,8-triCN; congeners with substitution patterns that are not thermodynamically favorable. These are believed to be products of PAH breakdown reactions and/or chlorophenol condensation. Overall, PCN formation is likely to occur via more than one pathway, including chlorination of naphthalene that is already present, de novo synthesis from PAHs and, possibly, chlorophenol condensation.

Organohalogen pollutants in herring from the northern Baltic Sea: concentrations, congener profiles and explanatory factors

Organohalogen contaminants were investigated in Baltic herring caught from three catchment areas in the Baltic Sea, off the coasts of Finland. Pools of both small and large herring were analysed for polychlorinated biphenyls (PCB), dibenzo-p-dioxins, dibenzofurans, naphthalenes, camphenes (toxaphene), polybrominated diphenyl ethers and the pesticide DDT and its metabolites. PCB concentrations per fresh weight in small herring were at the same level in all catchment areas, i.e. the Bothnian Bay, the Bothnian Sea and the Gulf of Finland, revealing no hot spots and reflecting most likely long term emissions and atmospheric deposition. Differences in the levels and/or congener profiles of other contaminants between catchment areas may be explained by point sources. Similar concentrations in small and large herring in the Gulf of Finland were possibly due to their common nutrition. In the other areas, differences between small and large herring most likely reflected their different food sources.