Chlorobiphenyl constituents of Aroclor 1268, Chlorofen, Clophen T 64, KC-600, and KC-1000 technical formulations

An updated global overview of the manufacture and unintentional formation of polychlorinated naphthalenes (PCNs)

This review updates information on the historical manufacture and unintentional production of polychlorinated naphthalenes (PCNs). The direct toxicity of PCNs as a result of occupational human exposure and through contaminated feed in livestock was recognised decades ago, making PCNs a precursor chemical for consideration in occupational medicine and occupational safety. This was confirmed by the listing of PCNs by the Stockholm Convention as a persistent organic pollutant in the environment, food, animals and humans. PCNs were manufactured globally between 1910 ∼ 1980, but reliable data on the volumes produced or national outputs are scarce. A total figure for global production would be useful for the purposes of inventory and control and it is clear that combustion related sources such as waste incineration, industrial metallurgy and use of chlorine are current major sources of PCNs to the environment. The upper bound estimate of total global production has been put at 400,000 metric tons but the amounts (at least, many 10 s of tonnes) that are currently emitted unintentionally every year through industrial combustion processes should also be inventoried along with estimates for emissions from bush and forest fires. This would however require considerable national effort, financing and co-operation from source operators. The historical (1910-1970 s) production and resulting emissions through diffusive/evaporative releases through usage, are still reflected in documented occurrence and patterns of PCNs in human milk in Europe and other locations worldwide. More recently, PCN occurrence in human milk from Chinese provinces has been linked to local unintentional emissions from thermal processes.

Environmental contaminants in coastal populations: Comparisons with the National Health and Nutrition Examination Survey (NHANES) and resident dolphins

BACKGROUND

People living in coastal communities are at risk for exposure to environmental hazards, including legacy chemicals. We can use databases such as NHANES to assess whether contaminants in coastal communities are present in higher levels than in the United States overall. We can use information from studies of local animal populations to assess which of these contaminants could have been transferred to people from their shared environment.

OBJECTIVE

Our objectives were to examine the POP profiles in human populations in areas where there are published POP profiles in resident dolphins and to compare our results with data from NHANES and the dolphin studies.

METHODS

We identified three areas where POPs have been analyzed in local resident dolphin populations (total N =73). We identified human communities in the same areas, and asked 27 eligible adults to read and sign a consent form, complete a questionnaire about demographics and seafood consumption, provide nine 10-mL blood samples, and provide one sample of seafood (N = 33). Blood and seafood were analyzed for a suite of POPs similar to those analyzed in published dolphin population studies. We compared the results from human blood analyses with NHANES and with data from the published reports of dolphin studies.

RESULTS

Levels and proportions of specific POPs found in people and animals reflect POPs found in the local environment. Compared with the nationally representative data reported in NHANES, the levels of many POPs found in high levels in dolphins were also higher in the corresponding human communities.

CONCLUSIONS

Contaminants measured in marine animals, such as dolphins, can be used to identify the types and relative levels of environmental contaminants expected to occur in people sharing the same environment. Likewise, contaminants measured in coastal human populations can provide insight into which contaminants may be found in nearby animal populations.

Degradation of one-side fully-chlorinated 1,2,3,4-tetrachloronaphthalene over Fe–Al composite oxides and its hypothesized reaction mechanism

Generated PeCNs to MoCNs congeners during the degradation of CN-27 over Fe–Al mixed composite oxides suggest the occurrence of successive hydrodechlorination and side chlorination pathways.

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.

By-side PCDD/Fs in technical PCB formulations of Kanechlor series

The Japanese Kanechlor technical PCB formulations such as KC-300, KC-400, KC-500, KC-600 and KC-1000 have been examined for possible contamination with by-side PCDD/Fs. 75 PCDDs and 135 PCDF have been determined using isotope dilution, separation and enrichment on silica gel impregnated with activated carbon, and final HRGC/HRMS measurement. MonoCDDs to OCDD were absent in KC-300, KC-600 and KC-1000. Tetra- and PentaCDDs occurred at > 1 ng/g in KC-400 and KC-500. The Kanechlors were contaminated with nearly all 135 PCDFsw. In parallel with an increasing degree of chlorination of a particular Kanechlor formulation examined increased also the content of more chlorinated PCDFs. In term of total dioxin-like toxicity and TEQ loads the KC-500 contained highly toxic PCDD/Fs at 270 ng TEQ/g and followed by KC-400 with 269 ng TEQ/g, KC-600 with 188 ng TEQ/g, KC-1000 with 164 ng TEQ/g and KC-300 with 79 ng TEQ/g. From 99.5 to 100% of PCDD/Fs toxicity found in the Kanechlors was from PCDFs.

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.

Dioxin-like compound load in bulk of Chlorofen--a technical chlorobiphenyl formulation from Poland

The results from inventory aiming to quantify production of individual chlorobiphenyl (CB) constituents and by-product impurities such as chlorodibenzo-p-dioxins (CDDs), chlorodibenzofurans (CDFs) and chloronaphthalenes (CNs) contained in the bulk of manufactured Chlorofen presented. 2,2',3,4,4',5,5'-Heptachlorobiphenyl (#180) is the most abundant constituent of Chlorofen and its historical production is estimated as 210 tones, and followed in decreasing order other major constituents are 2,2',3,3',4,4',5',6-/2,2',3,4,4',5,5',6-OcCB (#196/203), 2,2',3,3',4,4',5,5'-OcCB (#194), 2,2',3,3',4,5,6,6'-OcCB (#200) 2,2',3,3',4,5',6-HpCB (#175), 2,2',3,3',4,5,5',6-OcCB (#198) 2,2',3,3',4,5,5,'6'-OcCB (#199), 2,2',3,3',4,5',6-HpCB (#175), 2,2',3,4,5,5',6-HpCB (#185) and 2,2',4,4',5,5'-HxCB (#153), which contributed from 150 to 53 tones, respectively. Production of non-ortho CBs was 30.277 kg with 23 kg input from 3,3'4,4',5-PeCB (#126), while of mono-ortho CBs was 390 kg with 200 kg input from 2,3',4,4',5-PeCB (#118). 3,3'4,4',5-PeCB (#126) and 3,3',4,4',5,5'-HxCB (#169) with 2300 and 99 g of dioxin TEQ were major dioxin-like contributors among planar CBs in this formulation. CDDs and CDFs content of the bulk of Chlorofen was estimated as 0.11 and 319 kg, respectively, and the most toxic members are 0.355 and 99.6 g TEQ. 1,2,3,4,5,6,7-HpCN (#73) with 5.3 kg (53 g TEQ) 1,2,3,4,5,6,8-HpCN (#74) with 2.9 kg (29 g TEQ) and OCN with 370 kg (37000 g TEQ) dominated among CNs in bulk of Chlorofen. An especially large contribution form OCN is due to its relatively high extrapolated REP value and absolute concentration value reported.

Polychlorinated dibenzo-p-dioxins (PCDDs) and -furans (PCDFs) in pine needles of Poland

There is scarcity of data on sources, environmental diffusion and concentrations of PCDD/Fs and dioxin-like compounds in the Eastern and Central Europe. A study has been conducted using pine needles as passive matrix on diffusion of airborne 17 highly toxic PCDD/Fs in Poland. The target compounds were quantified using isotope dilution and HRGC/HRMS. One-year-old pine needles collected from 25 spatially distant sites in October 2002 revealed a relatively very low aerial emission and degree of pollution with PCDD/Fs. The most toxic 2,3,7,8-TCDD was absent (< 0.44 pg/g) in fresh pine needles sampled and absent at all sites were also 1,2,3,7,8-PeCDD, 1,2,3,4,7,8-HxCDD, 1,2,3,6,7,8-HxCDD, 1,2,3,7,8,9-HxCDD and 1,2,3,7,8,9-HxCDF (< 0.27 pg/g). OCDD at concentration range from 1.4 to 34 pg/g and OCDF at range from 1.5 to 41 pg/g were the only among 17 compounds found at each site, and next in prevalence was 1,2,3,4,7,8,9-HpCDF (total range from < 0.41 to 8.1 pg/g), which was found at 24 off 25 sites. The I-TEQ transformed concentrations of PCDD/Fs of pine needles of Poland ranged from < 0.01 to 1.28 pg/g ww or from 0.01 to 3.18 pg/g dw. The CDD/F homologue groups and congeners profiles of pine needles with highly dominant HpCDD/F and OCDD/F found in this survey suggest on lack of significant other than coal/lignite/wood combustiont sources of PCDD/Fs diffusion to ambient air in Poland.

PCB decomposition and formation in thermal treatment plant equipment

In this study we investigated both the decomposition and unintentional formation of polychlorinated biphenyl congeners during combustion experiments of refuse-derived fuel (RDF) and automobile shredder residue (ASR) at several stages in thermal treatment plant equipment composed of a primary combustion chamber, a secondary combustion chamber, and other equipments for flue gas treatment. In both experiments, the unintentional formation of PCB occurred in the primary combustion chamber at the same time as the decomposition of PCB in input samples. By combusting RDF, non-ortho-PCB predominantly formed, whereas ortho-PCB and symmetric chlorinated biphenyls (e.g., #52/69, #87/108, and #151) tended to be decomposed. ASR formed the higher chlorinated biphenyls more than RDF. These by-products from ASR had no structural relation with ortho-chlorine. Lower chlorinated biphenyls appeared as predominant homologues at the final exit site, while all congeners from lower to higher chlorinated PCB were unintentionally formed as by-products in the primary combustion chamber. This result showed that the flue gas treatment equipments effectively removed higher chlorinated PCB. Input marker congeners of RDF were #11, #39, and #68, while those for ASR were #11, #101, #110/120, and #118. Otherwise, combustion marker congeners of RDF were #13/12, #35, #77, and #126, while those for ASR were #170, #194, #206, and #209. While the concentration of PCB increased significantly in the primary combustion chamber, the value of toxicity equivalency quantity for dioxin-like PCB decreased in the secondary combustion chamber and the flue gas treatment equipments.

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.

Source determination of highly chlorinated biphenyl isomers in pine needles - comparison to several PCB preparations

The isomer specific composition of 13 technical PCB formulations of different origin and of pine needles was analyzed using GC/MS and HRGC/HRMS. Nonachlorinated biphenyls were identified in 11 among 13 formulations analyzed, with the highest abundance found for highly chlorinated ones (Aroclors 1268 and 1260, Chlorofen, Sovol, Kanechlors 600 and 500, Delor 106, Clophen A60). Decachlorobiphenyl was identified only in Aroclor 1268, Clophen A60, Aroclor 1260 and Chlorofen, comprising, respectively, 8.9, 2.8, 1.3 and 0.82% of the total bulk of nona- and decaCBs detected. Nona- and decaCB were detected in pine needles in Poland with the highest concentrations found at the sites neighboring to a former production sites of the Polish PCB formulations, while in pine needles collected around the Tokyo Bay nona- and decacCB were detected only in four of 10 sites and the concentrations corresponded to those found at the rural areas of Poland.

Assessment of dietary intake of polychlorinated biphenyls from a total diet study conducted in Pavia, Northern Italy

The diet is considered to be the main source of body burden of polychlorobiphenyls (PCBs) in the general population. The most cost-effective and reliable way to estimate the dietary intake is based on total diet studies (TDSs). The aim of the present study was to provide a reliable estimate of recent average dietary intakes of PCBs in Northern Italy. Congener-specific analysis of PCBs was undertaken on total diet samples collected at the cafeteria of the University of Pavia. The average daily intake for total PCBs was calculated to be 0.26 microg/person day-1. The major contributor to PCB intake was accounted for by pooled samples of bread, cereals and potatoes, followed by the protein composite, and fruit and vegetables. Although diverse dietary habits and differences in sampling and analytical procedures make comparison between different studies difficult, the daily intake of PCBs in Northern Italy can be located in the lower part of the range for values reported in the literature.