| 1. |
- Dahlén, Johan, et al.
(author)
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Determination of nitrate and other water quality parameters in groundwater from UV/Vis spectra employing partial least squares regression
- 2000
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In: Chemosphere. - : Pergamon Press. - 0045-6535 .- 1879-1298. ; 40:1, s. 71-77
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Journal article (peer-reviewed)abstract
- The use of UV/Vis spectroscopy in combination with partial least squares (PLS) regression for the simultaneous prediction of nitrate and non-purgeable organic carbon (NPOC) in groundwaters was evaluated. A model of high quality was obtained using first order derivative spectra in the range 200–300 nm. Inclusion of non-UV-absorbing constituents in the modeling procedure, i.e., chloride, sulfate, fluoride, total carbon (TC), inorganic carbon (IC), alkalinity, pH and conductivity was also evaluated. This model seemed to be useful for prediction of chloride, TC, IC, alkalinity and conductivity, while its ability to predict sulfate, fluoride and pH was poor. In conclusion, application of PLS regression, which requires neither filtration of samples nor addition of chemicals, is a promising alternative for fast interpretation of geochemical patterns of groundwater quality.
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| 2. |
- de Wit, Cynthia A
(author)
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An overview of brominated flame retardants in the environment.
- 2002
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In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 46:5, s. 583-624
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Journal article (peer-reviewed)abstract
- The presence of brominated flame retardant (BFR) chemicals, and particularly polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD), has become of increasing concern to scientists over the past decade. Environmental studies conducted primarily in Europe, Japan and North America indicate that these chemicals are ubiquitous in sediment and biota. The levels of PBDEs seem to be increasing, and several trends, including in humans, indicate that this increase may be rapid. The occurrence of high concentrations of certain PBDE isomers may be sufficient to elicit adverse effects in some wildlife. There is also concern that levels could cause adverse effects in sensitive human populations such as young children, indigenous peoples, and fish consumers. However, our knowledge about these chemicals, their sources, environmental behavior, and toxicity is limited, making risk assessment difficult. In this paper, the current state of knowledge is reviewed and areas for further research recommended to improve future monitoring and risk assessment efforts.
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| 3. |
- Dyke, P. H., et al.
(author)
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PCB and PAH releases from power stations and waste incineration processes in the UK
- 2003
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In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 50:4, s. 469-480
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Journal article (peer-reviewed)abstract
- This study focused on emissions of polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) from incineration and power generation processes. Increased concern over human exposure to both classes of compounds has meant that environmental regulators need to assess the contribution made by emissions from regulated processes to human exposure. In the first part of an assessment in the UK we reviewed literature data on emissions of PCB, focusing on the dioxin-like PCB assigned toxic equivalency factors by the World Health Organization, and PAR The literature study was supplemented by a series of plant tests to gather initial real plant data. Literature data were limited and the lack of standard protocols for measurement and reporting of both PCB and PAH meant that few data sets were comparable. Levels of dioxin-like PCB reported in the literature and measured in UK plant tests showed that well-controlled modern combustion plants with comprehensive pollution controls gave low emissions, typically about 5-10% of the toxic equivalent of the emissions of polychlorinated dibenzodioxins and dibenzofurans at the same plants and below the widely used standard of 0.1 ng TEQ/N m(3).
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| 4. |
- Engwall, Magnus, 1965-, et al.
(author)
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Uptake of dioxin-like compounds from sewage sludge into various plant species : assessment of levels using a sensitive bioassay
- 2000
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In: Chemosphere. - 0045-6535 .- 1879-1298. ; 40:9-11, s. 1189-1195
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Journal article (peer-reviewed)abstract
- A bioassay for the detection of dioxin-like compounds was used to estimate uptake of dioxin-like compounds in carrots, oil seed rape seeds, zucchinis and cucumbers grown in soil amended with sewage sludge from Swedish sewage treatment plants (STP), This sensitive bioassay is based on 7-ethoxyresorufin O-deethylase (EROD)-induction in cultured chicken embryo livers and reflects the combined biological effect of all dioxin-like compounds in a sample, including ones that seldom are analyzed. The bioassay detected low concentrations of dioxin-like compounds in all carrot, zucchini and cucumber samples, but did not detect any dioxin-like compounds in the rape seeds. In carrots the concentrations were increased up to seven times when grown in soil amended with high applications of some of the sludge samples, while others did not increase the concentrations compared to control. More realistic sludge applications only increased the concentrations slightly. The sludge-fertilized carrots contained the highest concentrations of the investigated plants (up to 14 pg bioassay-derived TCDD equivalents (bio-TEQs)/g d.w.). In the carrots, differences in uptake of dioxin-like compounds depended on the sludge origin, which may be due to more easily bioaccumulated dioxin-like compounds in some sludge samples, or other components that facilitated uptake into the carrots. In the cucumbers, a more than two-fold increase (from 0.2 to 0.5 pg bio-TEQs/g d.w.) was observed in specimens grown in sludge-amended soil when compared to controls, suggesting a small uptake from the roots to the shoots. No sludge-dependent increase in uptake was seen in the zucchini fruits. The bio-TEQ levels were generally low in the consumable above ground plant parts of the investigated species. However, the question if repeated sludge application results in a soil accumulation of dioxin-like compounds, thereby increasing the risk of plant uptake, remains to be investigated.
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| 5. |
- Eriksson, M., et al.
(author)
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Determination of hydrocarbons in old creosote contaminated soil using headspace solid phase microextraction and GC-MS
- 2001
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In: Chemosphere. - 0045-6535 .- 1879-1298. ; 44:7, s. 1641-1648
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Journal article (peer-reviewed)abstract
- Headspace solid phase microextraction (HS-SPME) has been used together with GC-MS to analyze organic substances directly in a soil, heavily contaminated with PAHs/creosote (similar to 300 mg/kg soil), from an old gaswork site in Stockholm, Sweden. The HS-SPME results, both qualitative and quantitative, were compared with traditional liquid extraction using ethyl acetate/hexane (20:80). It was shown that the concentrations determined with HS-SPME at 60 degreesC correlated well, for compounds containing up to two and three aromatic rings (naphthalenes, acenaphthene, acenaphthylene and fluorenes, while a lower concentration was obtained for phenanthrene, anthracene, fluoranthene and pyrene. The total concentrations for each compound determined with HS-SPME ranged from 2 to 25 mug/g soil. Quantification was done using standard addition of compounds directly to the soil samples. The bioavailable fraction of the compounds in the contaminated soil at 20 degreesC was analyzed using external calibration by spiking sterile uncontaminated sand (same texture and particle size as the contaminated soil but without a heavily sorbed organic fraction) with hydrocarbon standards in different concentrations. Storage of exposed fibers at 20 degreesC showed that analysis should be done within two days to make qualitative measurements and earlier (as soon as possible) for quantitative determinations.
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| 6. |
- Fiedler, Heidelore, 1953-, et al.
(author)
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PCDD/PCDF, chlorinated pesticides and PAH in Chinese teas
- 2002
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In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 46:9-10, s. 1429-1433
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Journal article (peer-reviewed)abstract
- Four samples of Chinese tea (two green teas, and two brick teas) were analyzed for their concentrations of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF), chlorinated pesticides and PAH. The infusions prepared from these teas were also analyzed for PCDD/PCDF. The levels of DDT and its metabolites in tea leaves were within the safety limit of 0.2 mg/kg. Rather high levels of total PAH were obtained in brick tea (1048-1162 mg/kg), when compared with green tea (497-517 mg/kg). In terms of PCDD/PCDF, the concentrations of green tea and brick tea differed by a factor of 16, while the concentrations of all infusions were within a factor of 2. The dioxin concentrations in green tea leaves can be explained through uptake of atmospheric PCDD/PCDF. The higher concentrations in the brick tea leaves are due the longer exposure time, and to certain extent, the use of old leaves, branches and roots when making the tea, and additional components such as soil particulates through contamination. Certain Chinese populations drinking a large amount of brick tea (>31 per day) indicated that individuals of these populations consume more tea than Europeans or North Americans result in a comparably higher intake of PCDD/PCDF. Tea consumption can attribute to up to 10% of the TDI recommended by WHO (only PCDD/PCDF considered, no PCB analyzed).
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| 7. |
- Heijerick, D. G., et al.
(author)
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Bioavailability of zinc in runoff water from roofing materials
- 2002
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In: Chemosphere. - 0045-6535 .- 1879-1298. ; 47:10, s. 1073-1080
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Journal article (peer-reviewed)abstract
- Corrosion and runoff from zinc-coated materials and outdoor structures is an important source for the dispersion of zinc in the environment. Being part of a large inter-disciplinary research project, this study presents the bioavailability of zinc in runoff water immediately after release from the surface of 15 different commercially available zinc-based materials exposed to the urban environment of Stockholm, Sweden. Runoff water was analysed chemically and evaluated for its possible environmental impact, using both a biosensor test with the bacteria Alcaligenes eutrophus (Biomet(R)) and the conventional 72 h growth inhibition test with the green alga Raphidocelis subcapitata. Chemical speciation modelling revealed that most zinc (94.3-99.9%) was present as the free Zn ion, the most bioavailable speciation form. These findings were confirmed by the results of the biosensor test (Biomet(R)) which indicated that all zinc was indeed bioavailable. Analysis of the ecotoxicity data also suggested that the observed toxic effects were due to the presence of Zn2+ ions. Finally, regression analysis showed that, for this type of runoff samples, the rapid screening biosensor was capable of predicting (a) the total amount of zinc present in the runoff samples (R-2 of 0.93-0.98; p < 0.05) and (b) the observed 72 h-EbC(50)s (R-2 of 0.69-0.97; p < 0.05).
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| 8. |
- Johansson, Emma, 1971-, et al.
(author)
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Spatial patterns of organic chlorine and chloride in Swedish forest soil
- 2003
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In: Chemosphere. - 0045-6535 .- 1879-1298. ; 52:2, s. 391-397
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Journal article (peer-reviewed)abstract
- The concentration of organic carbon, organic chlorine and chloride was determined in Swedish forest soil in the southern part of Sweden and the spatial distribution of the variables were studied. The concentration of organically bound chlorine was positively correlated to the organic carbon content, which is in line with previous studies. However, the spatial distribution patterns strongly indicate that some other variable adds structure to the spatial distribution of organic chlorine. The distribution patterns for chloride strongly resembled the distribution of organic chlorine. The spatial distribution of chloride in soil depends on the deposition pattern which in turn depends on prevailing wind-direction, amount of precipitation and the distance from the sea. This suggests that the occurrence of organic chlorine in soil is influenced by the deposition of chloride of some variable that co-varies with chloride. Two clearly confined strata were found in the area: the concentrations of organic chlorine and chloride in the western area were significantly higher than in the eastern area. No such difference among the two areas was seen regarding the carbon content.
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| 9. |
- Johansson, Inger, et al.
(author)
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Polycyclic aromatic hydrocarbons in weathered bottom ash from incineration of municipal solid waste
- 2003
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In: Chemosphere. - 0045-6535 .- 1879-1298. ; 53:2, s. 123-128
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Journal article (peer-reviewed)abstract
- Polycyclic aromatic hydrocarbons (PAHs) were analysed in weathered bottom ash from different municipal solid waste incinerators. The sum of the 16 "USEPA" PAHs was found to vary from 480 to 3590 mug/kg. The amounts of carcinogenic PAHs were between 89 and 438 mug/kg ash. The maximum levels of carcinogenic PAHs exceed the Swedish generic guidelines for sensitive land use. The results showed that the amount of PAHs in fresh and weathered bottom ash are similar, indicating that the PAHs are strongly bound to the ash and only limited amounts are released to'the surroundings. (C) 2003 Elsevier Ltd. All rights reserved.
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| 10. |
- Juhna, Talis, et al.
(author)
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Sorption of humic substances on aquifer material at artificial recharge of groundwater
- 2003
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In: Chemosphere. - 0045-6535 .- 1879-1298. ; 51:9, s. 861-8
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Journal article (peer-reviewed)abstract
- Experiments in batch equilibrium system were carried out to evaluate the importance of physical and chemical factors determining the sorption efficiency of humic substances (HS) on aquifer material, which has been used for artificial recharge of groundwater (ARG) in drinking water production. Results showed that an increase of the amount of clay in the aquifer material and a decrease of pH in water increased the sorption efficiency. The sorption of higher molecular weight, more hydrophobic and aromatic HS (Aldrich and forest soil humic acids) were greater than the sorption of acidic HS (river fulvic acids), either on the aquifer material or to its representative sorbing phases, clay and organic matter. The sorption on the aquifer material was largely due to physical sorption (hydrophobic attractions). This study showed the importance of HS composition on their removal during ARG and contributed to an understanding of the HS sorption mechanisms in this process
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