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- Bergknut, Magnus, et al.
(författare)
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Assessment of the availability of polycyclic aromatic hydrocarbons from gasworks soil using different extraction solvents and techniques
- 2004
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 23:8, s. 1861-1866
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Tidskriftsartikel (refereegranskat)abstract
- This study was designed to assess the availability of polycyclic aromatic hydrocarbons (PAHs) present at a gasworks site to different soil remediation techniques. The study examined the effect on PAH availability of using different organic solvents, the degree of pretreatment, and the extraction time. In total, 25 PAHs (with two to six fused rings) and five carbonyl derivatives were measured. The results indicated that the PAHs and their derivatives were bound loosely to the surface of the studied soil and that there were no significant kinetic boundaries associated with the extraction of the PAHs. Furthermore, it was concluded that the studied soil was not suitable for bioremediation, as the concentration of PAHs with low molecular weight were limited. However, pressurized liquid extraction (PLE) with methanol as the solvent extracted 97% of all PAHs and PAH-derivatives, indicating that extraction may be effective as part of a soil remediation technique for old gasworks soils.
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- Carlsson, Carina, et al.
(författare)
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Olfactory mucosal toxicity screening and multivariate QSAR modeling for chlorinated benzene derivatives
- 2004
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Ingår i: Archives of Toxicology. - : Springer Science and Business Media LLC. - 0340-5761 .- 1432-0738. ; 78:12, s. 706-715
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Tidskriftsartikel (refereegranskat)abstract
- The olfactory mucosa (OM) is an important target for metabolism-dependent toxicity of drugs and chemicals. Several OM toxicants share a 2,6-dichlorinated benzene structure. The herbicides dichlobenil (2,6-dichlorobenzonitrile) and chlorthiamide (2,6-dichlorothiobenzamide) and the environmental dichlobenil metabolite 2,6-dichlorobenzamide all induce toxicity in the OM following covalent binding in the Bowmans glands. In addition, we have shown that 2,6-dichlorophenyl methylsulfone targets the Bowmans glands and is probably the most potent OM toxicant so far described. These findings suggest that the 2,6-positioning of chlorines in combination with an electron-withdrawing group in the primary position of the benzene ring is an arrangement that facilitates OM toxicity. This study examined the physicochemical characteristics of the 2,6-dichlorinated OM toxicants. A number of 2,6-dichlorinated benzene derivatives with various types of substituents in primary position were tested for OM toxicity in mice. In addition, some other 2,6- and 2,5-substituted benzene derivatives were examined. Two novel OM toxicants, 2,6-dichlorobenzaldehyde oxime and 2,6-dichloronitrobenzene, were identified. By the use of partial least squares projection to latent structures with discriminant analysis (PLS-DA) a preliminary quantitative structure-activity relationship (QSAR) model was built also using reported OM toxicity data. Physicochemical properties positively correlated with olfactory mucosal toxicity were identified as molecular dipolar momentum and the electronic properties of the substituent. Inversely correlated descriptors were variables describing the hydrophobicity, electronic properties of the molecule such as electron affinity and the electronic charge on the primary carbon. In conclusion, this preliminary PLS-DA model shows that a 2,6-dichlorinated benzene derivative with a large, polar, and strong electron-withdrawing substituent in the primary position has the potential of being a potent OM toxicant in mice.
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- Fick, Jerker, et al.
(författare)
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Selection of antibiotics : A chemometric approach
- 2004
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Ingår i: 4th International Conference on Pharmaceuticals and Endocrine Disrupting Chemicals in Water, Minneapolis, USA. ; , s. 143-50
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Gadomski, Damien, et al.
(författare)
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Investigations into the Vertical Distribution of PCDDs and Mineralogy in Three Ball Clay Cores from the United States Exhibiting the Natural Formation Pattern
- 2004
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Ingår i: ENVIRONMENTAL SCIENCE & TECHNOLOGY. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 38:19, s. 4956-63
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we report the PCDD and mineralogical results from the analyses of 27 different samples from three ball clay cores from different locations in Kentucky and Tennessee. One goal of this study was to determine if there is a correlation between the mineralogy of the ball clay samples and the PCDD concentrations and/or homologue profiles in each sample. Samples from each of the three cores exhibited the natural formation profile with extremely high PCDD concentrations with low and mostly undetectable levels of polychlorinated dibenzofurans (PCDFs). The maximum toxic equivalents (TEQs) for Cores C-E were 2500, 440, and 15 000 pg WHO-TEQ/g, respectively. Although there does not seem to be a direct correlation between mineralogy and PCDD concentrations or homologue profiles, the mineralogy of Core C is substantially different than that of Cores D and E, which may in part explain the differences in congener patterns we observed among the three cores.
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- Jarnheimer, Per-åke, et al.
(författare)
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Fluoroquinolone Antibiotics in a Hospital Sewage Line; Occurrence, Distribution and Impact on Bacterial Resistance
- 2004
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 36:10, s. 752-5
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Tidskriftsartikel (refereegranskat)abstract
- In hospital sewage lines, human faecal bacteria are exposed to antibiotics, posing a risk for selection of antibiotic resistant microorganisms. We constructed a system for continuous sampling in a hospital sewage line that allowed us to study longitudinal establishment of bacteria, concentrations of antibiotics, and selection of bacterial resistance in waste water, sediment and biofilm. The focus in this study was on fluoroquinolones, a widely used group of antibiotics with increasing resistance problems. We found low levels of ciprofloxacin and ofloxacin in waste water but high concentrations in sediment. Despite the high levels of fluoroquinolones bound to sediment, we did not find any development of resistance against fluoroquinolones in Enterobacteriacae spp. and faecal enterococci isolated from sediment.
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