Carina Näf

PCBs, PCNs, PCDD/Fs, PAHs and Cl-PAHs in air and water particulate samples--patterns and variations

Methodology for the determination of biologically active polychlorinated biphenyls (PCBs), non-ortho PCBs, polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs) was used to investigate concentrations and patterns of certain chlorinated PAH (Cl-PAH) in source related samples using synthetic reference mixtures. Thus, in addition to the above mentioned compounds, mono-heptachlorosubstituted fluorenes, phenanthrenes/anthracenes and pyrenes/fluoranthenes (Cl-PAHs) were measured in vapour and particulate air samples from urban road tunnels, samples of settling particulate matter (SPM), and in bottom sediment samples from two point source locations (pulp and paper, and Mg-plant/Fe-Mn-smelter/chlor-alkali) and in the Baltic Sea. Concentrations in air samples followed: PAHs>PCBs>PCNs>non-ortho PCBs or Cl-PAHs>PCDD/Fs. SPM samples collected at increasing distance to the urban area of Stockholm showed: PAHs>PCBs>PCNs>PCDD/Fs>non-ortho PCBs or Cl-PAHs. For all compound groups there was a tenfold (Cl-PAHs fivefold) concentration decrease in SPM samples from highest levels in the urban water area to lowest levels at a distance of 26 km from city centre. PCB profiles of SPM showed similarities with combined profiles of Aroclor 1242 and 1254. PCN profiles of SPM showed similarities with combined profiles of Halowax 1099 and 1014. A correlation with concentration of all tested Cl-PAH and their corresponding parent PAH was found only for Cl-fluorene.

Toxicity and EROD-inducing potency of 24 polycyclic aromatic hydrocarbons (PAHs) in chick embryos

The toxicities (embryolethality) of 24 polycyclic aromatic hydrocarbons (PAHs) were determined in chick embryos using a 72-h test. The substances, dissolved in peanut oil, were injected into the air sacs of eggs preincubated for 7 days. LD50 values were determined for the four most toxic of the 24 compounds. Benzo [k] fluoranthene proved to be the most potent, with an LD50 of 14 μg (56 nmol)/kg egg. Dibenz[a,h]anthracene, benz[a]anthracene and benzo[b]naphtho[2,3-d]thiophene were a few times less toxic [LD50=39 μg (140 nmol)/kg, 79 μg (349 nmol)/kg and 82 μg (350 nmol)/kg, respectively]. The LD50 of benzo [k] fluoranthene was only about 5 times higher than that previously found for the most potent coplanar polychlorinated biphenyl (PCB), 3,3′,4,4′,5-pentachlorobiphenyl [LD50=3.1 μg (9.4 nmol)/kg], in the same kind of test. The toxicities of 18 of the PAHs in this study have also been evaluated previously using a 2-week test in chick embryos. Dibenz[a,h]anthracene, which had not been studied earlier in the 2-week test, proved to be almost as toxic as previously found for benzo [k] fluoranthene in that test. Several of the PAHs studied induced EROD activity in chick embryos, and, in general, the most toxic PAHs were also the most potent inducers of EROD. The highest enzyme activities were found after treatment with indeno[1,2,3-c,d]pyrene (12 times the control value) and dibenz[a,h]anthracene (8 times the control value). However, due to the high toxicity of dibenz[a,h]anthracene, the dose used was 7 times lower than that of indeno [1,2,3-c,d]pyrene. Following injection of PAHs on day 7, the EROD activities on day 10 were considerably lower than those obtained after a corresponding treatment with coplanar PCBs in an earlier study. Of the PAHs studied, some exhibited very high embryotoxicity. The most toxic PAHs induced EROD activity, suggesting that their toxicity was at least partly mediated via binding to the Ah receptor.

Potential biomagnification of PCDD/Fs - new possibilities for quantitative assessment using stable isotope trophic position

Abstract The transport of PCDD/Fs in two Baltic food chains is studied with a new method which quantitatively estimates biomagnification. Metabolic fractionation of stable isotopes of nitrogen is used to numerically estimate the trophic position of organisms. An application of the method to PCDD/F data from two Baltic food chains indicates that summed whole body concentrations of 2378-substituted PCDD/Fs decrease with increasing trophic position. The sum of TEQs however increases with trophic position. The main reason for this is the decrease in OCDD concentrations and a selective biomagnification of the three most toxic isomers 2378-TCDD, 23478-PnCDF and 12378-PnCDD.

Patterns and levels of organochlorines (DDTs, PCBs, non-ortho PCBs and PCDD/Fs) in male Harbour porpoises (Phocoena phocoena) from the Baltic Sea, the Kattegat-Skagerrak Seas and the west coast of Norway

Abstract Patterns and levels of chlorinated aromatic contaminants (DDTs, PCBs, non- ortho PCBs and PCDD/Fs) in blubber tissue were compared among six sample groups of male harbour porpoises ( Phocoena phocoena ) from the Baltic Sea, the Kattegat-Skagerrak Seas and the west coast of Norway. A principal component and classification analysis showed that mature harbour porpoises from the Baltic had significantly different contaminant patterns than animals from the Kattegat-Skagerrak and Norway. ANOVAs showed that mature porpoises from the Baltic had higher levels of ΣPCB and several individual PCBs and PCDD/Fs than the Kattegat-Skagerrak and the Norwegian samples and higher ΣDDT than the Norwegian. A comparison between immature porpoises showed that Baltic animals had higher levels of ΣPCDD/F than the corresponding sample from the Kattegat-Skagerrak. The levels of ΣDDT, ΣPCB and Σnon- ortho PCB were significantly higher in animals collected during 1978–81 compared to animals collected in 1988–90 indicating a temporal decline of these organochlorines in the Kattegat-Skagerrak Seas. The contaminant levels recorded in the Baltic Sea are a serious cause for concern and could have management implications for the already threatened harbour porpoises in this area.

An automated HPLC separation method with two coupled columns for the analysis of PCDD/Fs, PCBs AND PACs

Abstract A new automated separation method is described for the analysis of polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polycyclic aromatic compounds (PACs) and related compounds in complex environmental matrices. This high performance liquid chromatography (HPLC) method utilises a coupled column system consisting of an amino column and a porous graphitic carbon (PGC) column and allows for elution of the columns in both directions individually and in combination. The method combines the group separating properties of the amino column with the high selectivity of the carbon column for planar aromatic compounds. The switching of the columns is made in an automated mode and the system delivers five relevant fractions ready for injection on GC/MS. These fractions contain /1/ aliphatic/monoaromatic compounds, /2/ polycyclic aromatic compounds, /3/ PCBs with 2 or more chlorine atoms in ortho position (di-tetra-ortho PCBs), /4/ PCBs with one chlorine atom in ortho position (mono-ortho PCBs) and /5/ non-ortho PCBs and PCDD/Fs. The HPLC separation method presented reduces the time for analysis and improves the reproducibility.

Fingerprinting petroleum hydrocarbons in bottom sediment, plankton, and sediment trap collected seston

Abstract Water carried particulate matter (seston) collected in sediment traps has been used for fingerprinting petrogenic hydrocarbons (PHC) along an urban influenced transect in the Stockholm archipelago. Gas-chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) have been used for identification and quantification of n-alkanes, the isoprenoids pristane and phytane, pentacyclic triterpanes, the unresolved complex mixture (UCM) and total hydrocarbon content (THC). Preserved seston has been compared with anoxic seston and anoxic bottom surface sediments to establish the effects of degradation processes, and with spring bloom plankton as a reference of biological material. The results show that samples of seston, collected and preserved in sediment traps, are very suitable for carrying out fingerprint analyses of petrogenic hydrocarbons. A gradient of increasing PHC downflux towards the urban area was found and petrogenic contamination of the waters was detected along the whole transect.

Concentrations and spatial variations of cyclodienes and other organochlorines in herring and perch from the Baltic Sea.

Herring (Clupea harengus) and perch (Perca fluviatilis) were collected in the northern and southern Baltic Sea and analyzed for the presence of the cyclodiene pesticides chlordane (CHL), heptachlor, aldrin, dieldrin, endrin, isodrin, endosulfan and mirex, as well as other organochlorine contaminants, hexachlorocyclohexanes (HCHs), DDTs, hexachlorobenzene (HCBz) and polychlorinated biphenyls (PCBs) in order to investigate concentrations, accumulation and differences in geographical distribution. In the northern part of the Baltic Sea, Gulf of Bothnia, herring were collected at two pelagic stations, one in the Bothnian Bay (BB) and the other in the Bothnian Sea (BS), respectively; perch were collected at four coastal locations along the Swedish coast. All these locations were selected to represent background areas except one in the vicinity of an industrialised and contaminated area. Both specimens were also caught in the southern part of the Baltic Sea, in the Gulf of Gdansk (GG), Poland, a potentially highly polluted area. From the eight cyclodiene pesticides analyzed, three were detected in herring and perch samples, including 12 different CHL-related compounds, dieldrin and mirex. To our knowledge, it is the first time that mirex has been detected in samples from the Baltic Sea. Neither heptachlor, aldrin, endrin, isodrin nor endosulfan were found. However, HCHs, DDTs, HCBz and PCBs were found in every sample investigated, and the concentrations ranged e.g. for the cyclodiene chemicals dieldrin and CHL-related compounds from 30 to 170 ng/g lipid and for PCBs from 360 to 5400 ng/g lipid, both fish species included. Differences in contamination burden between the sites can be seen, e.g. for herring the BB and GG locals were similar, and generally lower than BS for all chemicals except that of DDT where GG was the highest. For the perch samples the industrialised location had markedly higher concentrations of HCBz and PCBs than the other locations. This species also identifies GG as the most DDT contaminated site among the three studied areas.

Levels of PCBs in the aquatic environment of the Gulf of Bothnia : Benthic species and sediments

Levels of PCBs in the aquatic environment of the Gulf of Bothnia: Benthic species and sediments

Levels of dioxin-like compounds in sewage sludge determined with a bioassay based on EROD induction in chicken embryo liver cultures.

A bioassay for the detection of dioxin-like compounds was used to estimate levels in sewage sludge from Swedish sewage treatment plants (STPs). The sludge extracts were HPLC-separated into three fractions containing a) monoaromatic/aliphatic, b) diaromatic (e.g. polychlorinated biphenyls [PCBs], polychlorinated dibenzodioxins and polychlorinated dibenzofurans [PCDDs/Fs]), and c) polyaromatic compounds (e.g. polycyclic aromatic hydrocarbons [PAHs]). The bioassay, which is based on EROD (7-ethoxyresorufin O-deethylase) induction in cultured chicken embryo livers detected dioxin-like activity in all unfractionated extracts and in the di- and polyaromatic fractions of all sludge extracts, but not in the monoaromatic/aliphatic fractions. The levels ranged between 6 and 109 pg bio-TEQ/g sludge (d.w.). In sediment samples from rural lakes in Sweden, levels of about 5 pg bio-TEQ/g (d.w.) have been found. The polyaromatic fractions of the sludge samples were potent in the bioassay, probably due to various PAHs and other polyaromatics in the sludge. The levels of six PAHs that are screened for in the sludge at Swedish STPs accounted for only 3-10% of the observed EROD-induction by the polyaromatic fractions. Consequently, many other polyaromatic EROD-inducing compounds were present in the sludge. Inclusion of a biological test like the chicken embryo liver bioassay in the screening of sludge would improve the ability to detect the presence of bioactive dioxin-like compounds. A theoretical estimation of bio-TEQ concentrations in farm-soil following long-term application of sludge with bio-TEQ concentrations similar to those observed in this investigation indicated that the bio-TEQ levels in soil would increase very slowly over time. The chicken embryo liver bioassay proved useful in assessing levels of dioxin-like compounds in sewage sludge and it gives valuable complementary information to chemical analysis data.

The importance of spheroidal carbonaceous particles (SCPs) for the distribution of particulate polycyclic aromatic hydrocarbons (PAHs) in an estuarine-like urban coastal water area

Abstract To investigate the correlation between PAHs (polycyclic aromatic hydrocarbons) and SCPs (spheroidal carbonaceous particles) derived from fossil fuel combustion, analyses were carried out on suspended particulate matter (SUPM) and settling particulate matter (SPM). The investigation was carried out in the estuarine-like coastal water area of Stockholm, northern Baltic proper. The SUPM was collected with a large volume tangential flow filtration technique and the SPM was collected with sediment traps at different stations, depths and seasons. Of eighteen PAHs analyzed all except four showed significant correlations (r=0.81–0.93) to SCPs. The results indicate a significant importance of SCPs for the distribution of PAH in this water area.