| 1. |
- Assefa, Anteneh Taye, et al.
(författare)
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Assessment of PCDD/F Source Contributions in Baltic Sea Sediment Core Records
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851 .- 1086-931X .- 1520-6912. ; 48:16, s. 9531-9539
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Tidskriftsartikel (refereegranskat)abstract
- Spatial and temporal trends of sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the Baltic Sea were evaluated by positive matrix factorization (PMF) and principal component analysis (PCA). Sediment cores were sampled at eight coastal, one coastal reference, and six offshore sites covering the northern to the southern Baltic Sea. The cores, which covered the period 1919-2010, were sliced into 2-3 cm disks among which 8-11 disks per core (in total 141 disks) were analyzed for all tetra- through octa-CDD/Fs. Identification and apportionment of PCDD/F sources was carried out using PMF. Five stable model PCDD/F congener patterns were identified, which could be associated with six historically important source types: (i) atmospheric background deposition (ABD), (ii) use and production of pentachlorophenol (PCP), (iii) use and production of tetra-chlorophenol (TeCP), (iv) high temperature processes (Thermal), (v) hexa-CDD-related sources (HxCDD), and (vi) chlorine-related sources (Chi), all of which were still represented in the surface layers. Overall, the last four decades of the period 1920-2010 have had a substantial influence on the Baltic Sea PCDD/F pollution, with 88 +/- 7% of the total amount accumulated during this time. The 1990s was the peak decade for all source types except TeCP, which peaked in the 1980s in the northern Baltic Sea and has still not peaked in the southern part. The combined impact of atmospheric-related emissions (ABD and Thermal) was dominant in the open sea system throughout the study period (1919-2010) and showed a decreasing south to north trend (always >80% in the south and >50% in the north). Accordingly, to further reduce levels of PCDD/Fs in the open Baltic Sea ecosystem, future actions should focus on reducing atmospheric emissions.
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| 2. |
- Bidleman, Terry F., et al.
(författare)
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Atmospheric transport and deposition of bromoanisoles along a temperate to arctic gradient
- 2017
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Ingår i: Environmental Science and Technology. - Washington : American Chemical Society (ACS). - 1086-931X .- 1520-6912 .- 0013-936X .- 1520-5851. ; 51:19, s. 10974-10982
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Tidskriftsartikel (refereegranskat)abstract
- Bromoanisoles (BAs) arise from O-methylation of bromophenols, produced by marine algae and invertebrates. BAs undergo sea-air exchange and are transported over the oceans. Here we report 2,4-DiBA and 2,4,6-TriBA in air and deposition on the Swedish west coast (Råö) and the interior of arctic Finland (Pallas). Results are discussed in perspective with previous measurements in the northern Baltic region in 2011−2013. BAs in air decreased from south to north in the order Råö > northern Baltic > Pallas. Geometric mean concentrations at Pallas increased significantly (p < 0.05) between 2002 and 2015 for 2,4-DiBA but not for 2,4,6-TriBA. The logarithm of BA partial pressures correlated significantly to reciprocal air temperature at the coastal station Råö and over the Baltic, but only weakly (2,4-DiBA) or not significantly (2,4,6-TriBA) at inland Pallas. Deposition fluxes of BAs were similar at both sites despite lower air concentrations at Pallas, due to greater precipitation scavenging at lower temperatures. Proportions of the two BAs in air and deposition were related to Henry’s law partitioning and source regions. Precipitation concentrations were 10−40% of those in surface water of Bothnian Bay, northern Baltic Sea. BAs deposited in the bay catchment likely enter rivers and provide an unexpected source to northern estuaries. BAs may be precursors to higher molecular weight compounds identified by others in Swedish inland lakes.
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| 3. |
- Brandsma, Sicco H., et al.
(författare)
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Two organophosphorus flame retardants, resorcinol bis (diphenylphosphate)(PBDPP) and bisphenol A bis (diphenylphosphate) (BPA-BDPP) used as alternatives for BDE209 detected in dust
- 2013
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 1086-931X .- 1520-6912 .- 0013-936X .- 1520-5851. ; 47:24, s. 14434-14441
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Tidskriftsartikel (refereegranskat)abstract
- Resorcinol bis(diphenylphosphate) (RBDPP) and bisphenol A bis(diphenylphosphate) (BPA-BDPP) are two halogen-free organophosphorus flame retardant (PFRs) that are used as an alternative for the decabromodiphenyl ether (Deca-BDE) technical mixture in TV/flatscreen housing and other electronic consumer products.' In this study, dust samples were collected from various microenvironments in The Netherlands (houses, cars), Greece.(houses), and Sweden (apartments, cars, furniture stores, electronics stores) and analyzed for RBDPP and BPA-BDPP. Additionally, the dust samples from The Netherlands were analyzed for decabromodiphenyl ether (BDE-209) for comparison and for TPHP, which is a byproduct in the RBDPP and BPA-BDPP technical products. BPA-BDPP was detected in almost all dust samples from The Netherlands, Greece, and Sweden. Highest concentrations were found in dust samples collected on electronic equipment from all three countries with BPA-BDPP levels ranging from <0.1 to 1300 mu g/g and RBDPP levels from <0.04 to 520 mu g/g. RBDPP and BPA-BDPP levels in dust collected further away from the electronics (source) were usually lower. BDE-209 levels in The Netherlands dust samples collected on and around the electronics were similar and much lower than the BPA-BDPP/RBDPP levels, indicating that the electronics were not the source of BDE-209. Strong positive correlations were found between TPHP concentrations and those of RBDPP (r = 0.805) and BPA-BDPP (r = 0.924), probably due to TPHP being a byproduct in commercial RBDPP and BPA-BDPP mixtures in electronics. To our knowledge, this is the first time that RBDPP and BPA-BDPP were detected in dust samples from Europe.
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| 4. |
- Börjesson, Gunnar, et al.
(författare)
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Methane fluxes from a Swedish landfill determined by geostatistical treatment of static chamber measurements
- 2000
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 1086-931X .- 1520-6912 .- 0013-936X .- 1520-5851. ; 34:18, s. 4044-4050
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Tidskriftsartikel (refereegranskat)abstract
- Methane emissions from a Swedish landfill were measured with a static chamber technique on three occasions during 1997. Methane flux rates ranged from -15.2 x 10-3 to 40 g of CH4 m-2 h-1, and the spatial variability was high (CV = 343-386%). The spatial distribution of the emissions was estimated with the help of ordinary kriging, which is a spatial interpolation method. Three different approaches to estimate the total amounts were used: kriging on logarithm-transformed data, kriging with extremes excluded, and linear interpolation of measurements. These were compared between themselves and with the flux rates measured with a tracer gas technique. While the latter gave an estimate of 41 kg of CH4 h-1 from the landfill (with small variations), the highest possible estimate obtained with static chambers and geostatistical methods was 9.7 kg of CH4 h-1. The conclusion is that static chambers can hardly be trusted for making more than small-scale estimates of landfill gas emissions.Methane emissions from a Swedish landfill were measured with a static chamber technique on three occasions during 1997. Methane flux rates ranged from -15.2 ╫ 10-3 to 40 g of CH4 m-2 h-1, and the spatial variability was high (CV = 343-386%). The spatial distribution of the emissions was estimated with the help of ordinary kriging, which is a spatial interpolation method. Three different approaches to estimate the total amounts were used: kriging on logarithm-transformed data, kriging with extremes excluded, and linear interpolation of measurements. These were compared between themselves and with the flux rates measured with a tracer gas technique. While the latter gave an estimate of 41 kg of CH4 h-1 from the landfill (with small variations), the highest possible estimate obtained with static chambers and geostatistical methods was 9.7 kg of CH4 h-1. The conclusion is that static chambers can hardly be trusted for making more than small-scale estimates of landfill gas emissions.
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| 5. |
- Destouni, G., et al.
(författare)
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General quantification of catchment-scale nutrient and pollutant transport through the subsurface to surface and coastal waters
- 2010
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 1086-931X .- 1520-6912 .- 0013-936X .- 1520-5851. ; 44:6, s. 2048-2055
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Tidskriftsartikel (refereegranskat)abstract
- This study develops a general quantification framework for consistent intermodel and intercatchment comparison of the nutrient and pollutant mass loading from multiple sources in a catchment area to downstream surface and coastal waters. The framework accounts for the wide spectrum of different transport pathways and travel times through the subsurface (soil, groundwater, sediment) and the linked surface (streams, lakes, wetlands) water systems of a catchment. The account is based on key flow partitioning and mass delivery fractions, which can be quantified differently by different flow and transport and reaction models. The framework application is exemplified for two Swedish catchment cases with regard to the transport of phosphorus and of a generic attenuating solute. The results show essential differences in model quantifications of transport pathways and temporal spreading, with important implications for our understanding of cause and effect in the catchment-scale nutrient and pollutant loading to downstream waters.
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| 6. |
- Drake, Henrik, 1979-, et al.
(författare)
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Incorporation of Metals into Calcite in a Deep Anoxic Granite Aquifer
- 2018
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851 .- 1086-931X .- 1520-6912. ; 52:2, s. 493-502
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Tidskriftsartikel (refereegranskat)abstract
- Understanding metal scavenging by calcite in deep aquifers in granite is of importance for deciphering and modeling hydrochemical fluctuations and water rock interaction in the upper crust and for retention mechanisms associated With underground, repositories for toxic wastes. Metal scavenging into calcite has generally been established in the laboratory or in natural environments that cannot be unreservedly applied to conditions in deep crystalline rocks, an environment of broad interest, for nuclear waste repositories. Here, we report a microanalytical study: of calcite precipitated over a period of 17 years from anoxic, low-temperature (14 degrees C), neutral (pH: 7.4-7.7), and brackish (Cl: 1700-7100 mg/L) groundwater flowing in fractures at >400 m depth in granite rock. This enabled assessment of the trace metal uptake by calcite under these deep-seated conditions. Aquatic speciation modeling was carried out to assess influence of metal complexation on the partitioning into calcite. The resulting environment-specific partition coefficients were for several divalent ions in line with values obtained in controlled laboratory experiments, whereas for several other ions they differed substantially. High absolute uptake of rare earth elements and U(IV) suggests that coprecipitation into calcite can be an important sink for these metals and analogousactinides in the vicinity of geological repositories.
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| 7. |
- Ejlertsson, Jörgen, et al.
(författare)
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Anaerobic Degradation of Nonylphenol Mono- and Diethoxylates in Digestor Sludge, Landfilled Municipal Solid Waste, and Landfilled Sludge
- 1999
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 1086-931X .- 1520-6912 .- 0013-936X .- 1520-5851. ; 33:2, s. 301-306
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the extent to which anaerobic digestor sludge, landfilled sludge, and landfilled municipal solid waste (MSW) degrade NPEOs under methanogenic conditions. NPEO1 and NPEO2 (NPEO1-2), used in a mixture, were chosen as model compounds. Anaerobic experimental bottles were amended with 100% digestor sludge at three different concentrations of NPEO1-2: 2, 60, and 308 mg L-1. [U-14C]-NPEO1-2 was used to detect any possible decomposition of the aromatic moiety of the NPEO1-2. All inoculates used degraded NPEO1-2 at 2 mg L-1, with nonylphenol (NP) forming the ultimate degradation product. The NP formed was not further degraded, and the incubations with labeled NPEO showed that the aromatic structure remained intact. Both landfill inoculates also transformed NPEO1-2 at 60 mg L-1. CH4 production was temporarily hampered in bottles with MSW landfill inoculum at 60 and 308 mg L-1. With 2 mg L-1 of NPEO, CH4 production closely followed that in the controls. Both NP and NPEO1-2 interacted with the organic matter which resulted in sorption to the solid phase.
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| 8. |
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| 9. |
- Kim, Jihee, et al.
(författare)
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Mass Budget of Methylmercury in the East Siberian Sea: The Importance of Sediment Sources
- 2020
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 1086-931X .- 1520-6912 .- 0013-936X .- 1520-5851.
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Tidskriftsartikel (refereegranskat)abstract
- Biological concentrations of methylmercury(MeHg) are elevated throughout the Arctic Ocean; however, to date, the major sources and the spatial variability of MeHg are not well quantified. To identify the major inputs and outputs of MeHg to the Arctic shelf water column, we measured MeHg concentrations in the seawater and sediment samples from the East Siberian Sea collected from August to September 2018. We found that the MeHg concentrations in seawater and pore water were higher on the slope than on the shelf, while the MeHg concentrations in the sediment were higher on the shelf than on the slope. We created a mass budget for MeHg and found that the benthic diffusion and resuspension largely exceed other sources, such as atmospheric deposition and river water input. The major sinks of MeHg in the water column were dark demethylation and evasion. When we extrapolated our findings on benthic diffusion to the entire Arctic shelf system, the annual MeHg diffusion from the shelf sediments was estimated to be 23,065 ± 939 mol yr−1, about 2 times higher than previously proposed river discharges. Our study suggests that the MeHg input from shelf sediments in the Arctic Ocean is significant and has been previously underestimated.
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| 10. |
- Lemieux, Christine L, et al.
(författare)
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Cancer Risk Assessment of Polycyclic Aromatic Hydrocarbon Contaminated Soils Determined Using Bioassay-Derived Levels of Benzo[a]pyrene Equivalents
- 2015
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 1086-931X .- 1520-6912 .- 0013-936X .- 1520-5851. ; 49:3, s. 1797-1805
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Tidskriftsartikel (refereegranskat)abstract
- Here we evaluate the excess lifetime cancer risk (ELCR) posed by 10 PAH-contaminated soils using (i) the currently advocated, targeted chemical-specific approach that assumes dose additivity for carcinogenic PAHs and (ii) a bioassay-based approach that employs the in vitro mutagenic activity of the soil fractions to determine levels of benzo[a]pyrene equivalents and, by extension, ELCR. Mutagenic activity results are presented in our companion paper.1 The results show that ELCR values for the PAH-containing fractions, determined using the chemical-specific approach, are generally (i.e., 8 out of 10) greater than those calculated using the bioassay-based approach; most are less than 5-fold greater. Only two chemical-specific ELCR estimates are less than their corresponding bioassay-derived values; differences are less than 10%. The bioassay-based approach, which permits estimation of ELCR without a priori knowledge of mixture composition, proved to be a useful tool to evaluate the chemical-specific approach. The results suggest that ELCR estimates for complex PAH mixtures determined using a targeted, chemical-specific approach are reasonable, albeit conservative. Calculated risk estimates still depend on contentious PEFs and cancer slope factors. Follow-up in vivo mutagenicity assessments will be required to validate the results and their relevance for human health risk assessment of PAH-contaminated soils
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