| 1. |
- Olsman [Takner], Helena, et al.
(author)
-
Relative differences in aryl hydrocarbon receptor-mediated response for 18 polybrominated and mixed halogenated dibenzo-p-dioxins and -furans in cell lines from four different species
- 2007
-
In: Environmental Toxicology and Chemistry. - 0730-7268 .- 1552-8618. ; 26:11, s. 2448-2454
-
Journal article (other academic/artistic)abstract
- As a consequence of ubiquitous use of brominated organic chemicals, there is a concern for persistent or increasing environmental levels of polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) and mixed polychlorinated and polybrominated dibenzo-p-dioxins/furans (PXDD/Fs). Hence, there is a need to broaden the toxicological and environmental knowledge about these compounds, as a basis for risk assessment. In the study presented here, the relative potencies (REPs) for 18 PBDD/F and PXDD/ F congeners were determined in four dioxin-specific bioassays from different species: dioxin receptor chemically activated luciferase expression assay (DR-CALUX, rat hepatoma cells), TV101L (human hepatoma cells), and GPC.2D (guinea pig adenoma cells), as well as ethoxyresorufin-O-deethylase induction in the fish cell line RTL-W1 (rainbow trout liver cells). The bioassay specific REP factors presented here enable the assessment of the contribution from PBDD/Fs and PXDD/Fs to total 2,3,7,8-tetrachl orodibenzop-dioxin (TCDD) equivalents (TEQs: toxic equivalents), using bioassay analysis. The PBDD/Fs were found to be equally potent as their chlorinated analogues in the three mammalian assays, whereas the PXDD/Fs showed relatively higher potencies. Of special concern were the 2,3,7,8-substituted penta- and tetrahalogenated congeners, for which mean REPs were >= 1. The 2-B-1,3,7,8-CDD (2-bromo-1,3,7,8-tetrachlorodibenzo-p-dioxin) was up to three times more potent than TCDD in individual experiments (on weight basis). The RTL-W1 was less sensitive to the tested compounds with overall 10-fold lower REPs than the mammalian cell lines. Although the REP factors exhibited species-specific differences, overall resembling rank orders of dioxin-like potency were obtained.
|
|
| 2. |
- Gustavsson, Lillemor, et al.
(author)
-
Reed beds receiving industrial sludge containing nitroaromatic compounds : Effects of outgoing water and bed material extracts in the umu-c genotoxicity assay, DR-CALUX assay and on early life stage development in Zebrafish (Danio rerio)
- 2007
-
In: Environmental Science and Pollution Research. - Berlin : Springer. - 0944-1344 .- 1614-7499. ; 14:3, s. 202-211
-
Journal article (peer-reviewed)abstract
- Goal, Scope and Background: Sweden has prohibited the deposition of organic waste since January, 2005. Since 1 million tons of sludge is produced every year in Sweden and the capacity for incineration does not fill the demands, other methods of sludge management have to be introduced to a larger degree. One common method in the USA and parts of Europe is the use of wetlands to treat wastewater and sewage sludge. The capacity of reed beds to affect the toxicity of a complex mixture of nitroaromatics in sludge, however, is not fully elucidated. In this study, an industrial sludge containing explosives and pharmaceutical residues was therefore treated in artificial reed beds and the change in toxicity was studied. Nitroaromatic compounds, which are the main ingredients of many pharmaceuticals and explosives, are well known to cause cytotoxicity and genotoxicity. Recently performed studies have also showed that embryos of zebrafish (Danio rerio) are sensitive to nitroaromatic compounds. Therefore, we tested the sludge passing through constructed wetlands in order to detect any changes in levels of embryotoxicity, genotoxicity and dioxin-like activity (AhR-agonists). We also compared unplanted and planted systems in order to examine the impact of the root system on the fate of the toxicants. Methods: An industrial sludge containing a complex mixture of nitroaromatics was added daily to small-scale constructed wetlands (vertical flow), both unplanted and planted with Phragmites australis. Sludge with an average dry weight of 1.25%, was added with an average hydraulic loading rate of 1.2 L/day. Outgoing water was collected daily and stored at −20°C. The artificial wetland sediment was Soxhlet extracted, followed by clean-up with multi-layer silica, or extracted by ultrasonic treatment, yielding one organic extract and one water extract of the same sample. Genotoxicity of the extracts was measured according to the ISO protocol for the umu-C genotoxicity assay (ISO/TC 147/SC 5/WG9 N8), using Salmonella typhimurium TA1535/pSK1002 as test organism. Embryotoxicity and teratogenicity were studied using the fish egg assay with zebrafish (Danio rerio) and the dioxin-like activity was measured using the DR-CALUX assay. Chemical analyses of nitroaromatic compounds were performed using Solid Phase Micro Extraction (SPME) and GC-MS. Results: Organic extracts of the bed material showed toxic potential in all three toxicity tests after two years of sludge loading. There was a difference between the planted and the unplanted beds, where the toxicity of organic extracts overall was higher in the bed material from the planted beds. The higher toxicity of the planted beds could have been caused by the higher levels of total carbon in the planted beds, which binds organic toxicants, and by enrichment caused by lower volumes of outgoing water from the planted beds. Discussion: Developmental disorders were observed in zebrafish exposed directly in contact to bed material from unplanted beds, but not in fish exposed to bed material from planted beds. Hatching rates were slightly lower in zebrafish exposed to outgoing water from unplanted beds than in embryos exposed to outgoing water from planted beds. Genotoxicity in the outgoing water was below detection limit for both planted and unplanted beds. Most of the added toxicants via the sludge were unaccounted for in the outgoing water, suggesting that the beds had toxicant removal potential, although the mechanisms behind this remain unknown. Conclusions: During the experimental period, the beds received a sludge volume (dry weight) of around three times their own volume. In spite of this, the toxicity in the bed material was lower than in the sludge. Thus, the beds were probably able to actually decrease the toxicity of the added, sludge-associated toxicants. When testing the acetone extracts of the bed material, the planted bed showed a higher toxicity than the unplanted beds in all three toxicity tests. The toxicity of water extracts from the unplanted beds, detected by the fish egg assay, were higher than the water extracts from the planted beds. No genotoxicity was detected in outgoing water from either planted or unplanted beds. All this together indicates that the planted reed beds retained semi-lipophilic acetone-soluble toxic compounds from the sludge better than the unplanted beds, which tended to leak out more of the water soluble toxic compounds in the outgoing water. The compounds identified by SPME/GC in the outgoing water were not in sufficient concentrations to have caused induction in the genotoxicity test. Recommendations and Perspectives: This study has pointed out the benefits of using constructed wetlands receiving an industrial sludge containing a complex mixture of nitroaromatics to reduce toxicity in the outgoing water. The water from planted, constructed wetlands could therefore be directed to a recipient without further cleaning. The bed material should be investigated over a longer period of time in order to evaluate potential accumulation and leakage prior to proper usage or storage. The plants should be investigated in order to examine uptake and possible release when the plant biomass is degraded.
|
|
| 3. |
- Boström, Björn, et al.
(author)
-
Isotope fractionation and 13C enrichment in soil profiles during the decomposition of soil organic matter
- 2007
-
In: Oecologia. - Berlin : Springer. - 0029-8549 .- 1432-1939. ; 153:1, s. 89-98
-
Journal article (peer-reviewed)abstract
- The mechanisms behind the 13C enrichment of organic matter with increasing soil depth in forests are unclear. To determine if 13C discrimination during respiration could contribute to this pattern, we compared d13C signatures of respired CO2 from sieved mineral soil, litter layer and litterfall with measurements of d13C and d15N of mineral soil, litter layer, litterfall, roots and fungal mycelia sampled from a 68-year-old Norway spruce forest stand planted on previously cultivated land. Because the land was subjected to ploughing before establishment of the forest stand, shifts in d13C in the top 20 cm reflect processes that have been active since the beginning of the reforestation process. As 13C-depleted organic matter accumulated in the upper soil, a 1.0 o/oo d13C gradient from –28.5 o/oo in the litter layer to –27.6 o/oo at a depth of 2–6 cm was formed. This can be explained by the 1 o/oo drop in d13C of atmospheric CO2 since the beginning of reforestation together with the mixing of new C (forest) and old C (farmland). However, the isotopic change of the atmospheric CO2 explains only a portion of the additional 1.0& increase in d13C below a depth of 20 cm. The d13C of the respired CO2 was similar to that of the organic matter in the upper soil layers but became increasingly 13C enriched with depth, up to 2.5 o/oo relative to the organic matter. We hypothesise that this 13C enrichment of the CO2 as well as the residual increase in d13C of the organic matter below a soil depth of 20 cm results from the increased contribution of 13C-enriched microbially derived C with depth. Our results suggest that 13C discrimination during microbial respiration does not contribute to the 13C enrichment of organic matter in soils. We therefore recommend that these results should be taken into consideration when natural variations in d13C of respired CO2 are used to separate different components of soil respiration or ecosystem respiration.
|
|
| 4. |
- Ericson Jogsten, Ingrid, et al.
(author)
-
Perfluorinated chemicals in blood of residents in Catalonia (Spain) in relation to age and gender : a pilot study
- 2007
-
In: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 33:5, s. 616-623
-
Journal article (peer-reviewed)abstract
- Fluorinated organic compounds (FOCs) are a group of chemicals widely used as surfactants, lubricants, polymers, and fire-fighting foams. Recent studies have shown the ubiquitous distribution of FOCs in the environment, wildlife, and humans. We here report the results of a pilot study conducted to provide preliminary data on the levels of 13 FOCs in the blood of 48 residents in Catalonia, Spain, in relation to gender and age (25+/-5 and 55+/-5 years). The highest mean concentration was obtained for perfluorooctane sulfonate (PFOS, 7.64 ng/ml), followed by perfluorohexane sulfonate (PFHxS, 3.56 ng/ml) and perfluorooctanoic acid (PFOA, 1.80 ng/ml). Four other FOCs showed mean levels between 0.30 and 0.44 ng/ml, whereas those of the remaining 6 compounds were below the detection limit. Regarding gender, the blood levels of PFHxS and PFOA were significantly higher (p<0.05) in men than in women, while differences according to age were only noted for PFHxS (p<0.05) and perfluorooctane sulfonamide (PFOSA) (p<0.001), for which the levels were higher in the younger (25+/-5 years) group of subjects. A significant correlation between PFOS levels and those of the remaining detected FOCs (except PFDA) was found. In general terms, the current FOC concentrations were lower than those found in recent studies concerning levels of these chemicals in human blood and serum of subjects from different countries.
|
|
| 5. |
|
|
| 6. |
- Knudsen, Lisa B., et al.
(author)
-
Halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis) : levels, relationships to dietary descriptors and blood to liver comparison
- 2007
-
In: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 146:1, s. 25-33
-
Journal article (peer-reviewed)abstract
- The northern fulmar (Fulmarus glacialis) is an interesting candidate for the study of patterns and levels of halogenated organic contaminants (HOCs) since they accumulate high levels of certain HOCs. In the present study we characterized a suite of established and novel HOCs in northern fulmars breeding on Bjørnøya in the Norwegian Arctic. A comparison between blood and liver HOC levels was made, and the levels were related to the ratios of heavier to lighter stable isotopes of nitrogen (15)N/(14)N (delta(15)N) and carbon (13)C/(12)C (delta(13)C) in muscle. A significant difference in congener patterns between blood and liver was found. The delta(13)C was not related to HOCs, neither in liver nor in blood. Weak correlations were found between delta(15)N and liver HOC levels. The 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) in northern fulmars were well above thresholds for reproductive effects in seabirds.
|
|
| 7. |
- Bergknut, Magnus, et al.
(author)
-
Identification of potentially toxic compounds in complex extracts of environmental samples using gas chromatography-mass spectrometry and multivariate data analysis
- 2007
-
In: Environmental Toxicology and Chemistry. - New York : Pergamon. - 0730-7268 .- 1552-8618. ; 26:2, s. 208-217
-
Journal article (peer-reviewed)abstract
- In this study, we examined 31 samples of varying chemical composition, including samples of soils from gasworks, coke production sites, and sites where wood preservatives were heavily used; ash and soot from municipal solid waste incinerators; antiskid sand; and dust from areas with heavy road traffic. The samples were comprehensively chemically characterized, especially their polycyclic aromatic compound contents, using gas chromatography-time-of-flight mass spectrometry, whereas their biological effects were assessed using dehydrogenase activity, root growth (Hordeum vulgare), reproduction of springtails (Folsomia candida), algal growth (Desmodesmus subspicatus), germinability (Sinapis alba), Vibrio fischeri, DR-CALUX, and Ames Salmonella assays. The number of compounds detected in the samples ranged from 123 to 527. Using the multivariate regression technique of partial-least-squares projections to latent structures, it was possible to find individual compounds that exhibited strong correlations with the different biological responses. Some of the results, however, indicate that a broader chemical characterization may be needed to identify all the compounds that may cause the measured biological responses.
|
|
| 8. |
- Greis, Christina, 1975-, et al.
(author)
-
Plutonium remobilization in a humic-rich lake
- 2007
-
In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 277:1, s. 265-268
-
Journal article (peer-reviewed)abstract
- Fresh water from Lake Svartsjön, Sweden, was collected and four fractions were prepared: (1) adsorption on DEAE, (2) flocculation with Ca2+, (3) co-precipitation with Fe hydrous oxide and (4) co-precipitation with Mn hydrous oxide. The plutonium level in the lake is 65 fg/l (222 μBq/l), measured by ICP-QMS and ICP-SFMS. Pronounced accumulation in fractions (1) (34%) and (2) (66%), combined with observed levels of organic matter indicate that plutonium is predominantly associated with organic matter. Measurements of isotopic ratios indicate that 77% of the plutonium originates from weapons testing and the remaining appears to originate from the Chernobyl accident.
|
|
| 9. |
- Greis, Christina, 1975-
(author)
-
Rapid analysis of actinide isotopes using quadrupole ICP-MS for emergency preparedness and environmental monitoring
- 2007
-
Doctoral thesis (other academic/artistic)abstract
- Transuranium elements in the environment are mainly derived from nuclear weapons testing and the nuclear fuel cycle. Of growing concern are illicit nuclear trafficking and the threat of terror acts. The development of rational methods, for environmental monitoring and for tracing sources of nuclear and radioactive materials in the environment, is constantly required. Traditionally, the actinides have been determined by radiometric techniques. These analyses can be time consuming for elements at low concentrations and with long half-lives. This thesis addresses the determination of actinides, especially plutonium, in environmental samples with ICP-QMS (inductively coupled plasma quadrupole mass spectrometry). The ICP-QMS instrument was equipped with an USN (ultrasonic nebuliser), which proved to be a successful combination for the determination of plutonium at low concentrations in acidified solutions after separation with anion exchange. The detection limit for plutonium was in the range 10-30 pg/l with a RSD of 1-10%. The suitability of chemical separation was evaluated for anion exchange, liquid-liquid-extraction and extraction chromatography. The outlined procedure, including sample dissolution, chemical separation and analysis, for determination of actinides in environmental matrices proved to be accurate and reliable. Quality assurance of the procedure was performed during an intercomparison exercise and with reference materials. The detection accuracy has also been validated with α-spectrometry and ICP-SFMS. The procedure has been applied to saline sediments and fresh water sediments as well as several fresh water matrices.
|
|
| 10. |
- Hyvonen, R., et al.
(author)
-
The likely impact of elevated [CO2], nitrogen deposition, increased temperature and management on carbon sequestration in temperate and boreal forest ecosystems: a literature review
- 2007
-
In: New Phytologist. - Cambridge : Wiley. - 0028-646X .- 1469-8137. ; 173:3, s. 463-480
-
Research review (peer-reviewed)abstract
- Temperate and boreal forest ecosystems contain a large part of the carbon stored on land, in the form of both biomass and soil organic matter. Increasing atmospheric [CO2], increasing temperature, elevated nitrogen deposition and intensified management will change this C store. Well documented single-factor responses of net primary production are: higher photosynthetic rate (the main [CO2] response); increasing length of growing season (the main temperature response); and higher leaf-area index (the main N deposition and partly [CO2] response). Soil organic matter will increase with increasing litter input, although priming may decrease the soil C stock initially, but litter quality effects should be minimal (response to [CO2], N deposition, and temperature); will decrease because of increasing temperature; and will increase because of retardation of decomposition with N deposition, although the rate of decomposition of high-quality litter can be increased and that of low-quality litter decreased. Single-factor responses can be misleading because of interactions between factors, in particular those between N and other factors, and indirect effects such as increased N availability from temperature-induced decomposition. In the long term the strength of feedbacks, for example the increasing demand for N from increased growth, will dominate over short-term responses to single factors. However, management has considerable potential for controlling the C store.
|
|
