| 1. |
- Biester, Harald, et al.
(författare)
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Mercury in mires
- 2006
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Ingår i: Peatlands. - : Elsevier. - 9780080468051 - 9780444528834 ; , s. 465-478
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Bokkapitel (refereegranskat)abstract
- This chapter illustrates that a better understanding of the behavior of mercury in the environment is needed for a number of reasons. For example, increased biomagnification of mercury in aquatic food chains, especially in fish, and enhanced accumulation in remote areas such as the Arctic have been observed in the last few decades. Mercury toxicity in aquatic ecosystems is of particular concern, with the role of methylmercury (MeHg) being critical. This compound can be concentrated by more than a million times in the aquatic food chain. Biogeochemical studies and monitoring programs that include direct measurements of wet deposition or indirect measurements based on biomonitoring of forest mosses, have established that anthropogenic activities have affected the global cycling of mercury. Although a precise link has yet to be made between the increased content of mercury in biota and the increased accumulation rates observed in natural environmental archives, such as peat, lake sediments, and glacial ice, there is broad consensus that these archives provide a means to reconstruct atmospheric deposition trends at local, regional, and global scales.
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| 2. |
- Biester, Harald, et al.
(författare)
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Modeling the Past Atmospheric Deposition of Mercury Using Natural Archives
- 2007
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 41:14, s. 4851-4860
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Tidskriftsartikel (refereegranskat)abstract
- Historical records of mercury (Hg) accumulation in lake sediments and peat bogs are often used to estimate human impacts on the biogeochemical cycling of mercury. On the basis of studies of lake sediments, modern atmospheric mercury deposition rates are estimated to have increased by a factor of 3-5 compared to background values: i.e., from about 3-3.5 g Hg m-2 yr-1 to 10-20 g Hg m-2 yr-1. However, recent studies of the historical mercury record in peat bogs suggest significantly higher increases (9-400 fold, median 40×), i.e., from about 0.6-1.7 g Hg m-2 yr -1 to 8-184 g Hg m-2 yr -1. We compared published data of background and modern mercury accumulation rates derived from globally distributed lake sediments and peat bogs and discuss reasons for the differences observed in absolute values and in the relative increase in the industrial age. Direct measurements of modern wet mercury deposition rates in remote areas are presently about 1-4 g m-2 yr -1, but were possibly as high as 20 g Hg m-2 yr -1 during the 1980s. These values are closer to the estimates of past deposition determined from lake sediments, which suggests that modern mercury accumulation rates derived from peat bogs tend to over-estimate deposition. We suggest that smearing of 210Pb in the uppermost peat sections contributes to an underestimation of peat ages, which is the most important reason for the overestimation of mercury accumulation rates in many bogs. The lower background mercury accumulation rates in peat as compared to lake sediments we believe is the result of nonquantitative retention and loss of mercury during peat diagenesis. As many processes controlling time-resolved mercury accumulation in mires are still poorly understood, lake sediments appear to be the more reliable archive for estimating historical mercury accumulation rates.
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| 3. |
- Bindler, Richard, et al.
(författare)
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Beyond the peat : synthesizing peat, lake sediments and soils in studies of the Swedish environment
- 2006
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Ingår i: Peatlands. - : Elsevier. - 9780080468051 - 9780444528834 ; , s. 431-448
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter illustrates on comparing peat and lake sediment records and linking the quantitative record of metals in peat to contemporary environmental problems. Quantifying metal records in peat has been an important step, but new research needs to move beyond this and consider how to apply these data. Lead analyses, including stable isotopes, are now fairly routine and based on these analyses the historical trends of lead deposition are now well established in peat, lake sediments and even glacial ice. The biogeochemical cycling of lead has also been well researched, which allows making this link between the historical lead record and soil biogeochemistry. Because peat and lake sediments seem to record the same changes in mercury deposition, there is similar promise in linking the long-term peat record of mercury and other metals with biogeochemical cycling of mercury and other important metals in forests and soils.
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| 4. |
- Bindler, Richard, et al.
(författare)
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Bridging the gap between ancient metal pollution and contemporary biogeochemistry
- 2008
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Ingår i: Journal of Paleolimnology. - : Springer. - 0921-2728 .- 1573-0417. ; 40:3, s. 755-770
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Tidskriftsartikel (refereegranskat)abstract
- Paleolimnology provides long-term data that are often essential for understanding the current state of the environment. Even though there is great potential, paleolimnology is rarely used together with process-related studies to solve issues regarding cycling of elements in the environment. Clearly, this is a drawback because the cycling of many elements, which cause great concern in the present-day environment, was altered long before the advent of monitoring programs. The pioneering work of C.C. Patterson and his colleagues emphasized the importance of a long-term perspective for understanding the current cycling of metals, with a focus on lead, and in particular for estimating background concentrations and human-related impacts in the environment. In Sweden the first traces of atmospheric lead pollution are found in lake sediments dated to about 3500 years ago. The long-term changes in the pollution lead record in lake sediments led us to consider how lead biogeochemistry has changed over time in response to this historical deposition‹where has this lead gone, and how much does this lead contribute to the present-day biogeochemical cycling of lead? How was lead distributed in Œpre-industrial¹ soils or more properly in natural soils not impacted by atmospheric pollution? There are many studies that have examined the effects of increased metal concentrations on soil biota, but what are the appropriate background conditions for comparison? Using lake sediments as our foundation we have analyzed lead, including its stable isotopes, in other environmental compartments, including peat, soil, and a range of boreal forest plant species, to develop a better understanding of the fate of lead derived from long-term pollution. Three important conclusions from our studies in Sweden are: (1) atmospheric lead deposition rates during the 20th century were 100 to as much as 1000 times higher than natural deposition rates a few thousand years ago. Even with stricter emission standards during the past three decades and the resultant reductions in deposition, lead deposition rates today are still 10100 times greater than natural rates. This increase in deposition rates modeled from sediment and peat records is of a similar scale to estimated changes in body burdens of lead in modern versus ancient humans. (2) In Europe about half of the cumulative burden of atmospherically deposited lead was deposited before industrialization. In southern Sweden the cumulative burden of pollution lead during the past 3500 years is 25 g Pb m-2 and in the Œpristine¹ northern parts of the country there is about 1 g Pb m-2. (3) Predicted recovery rates for soils are slow; in the cold climate of Scandinavia, we find that the soil surface (O horizon), where most soil biota reside, retains lead deposited over the past 150500 years. Therefore, although lead deposition rates in Europe, as well as N. America, are only 10% of those a few decades ago, it will take several decades or longer for lead concentrations in soils to respond appreciably. The slow turnover rates for lead in the environment and gradual immobilization of lead in deeper soil mineral horizons also inhibits a loss of lead to surface waters in areas removed from point sources.
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| 5. |
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| 6. |
- Bindler, Richard
(författare)
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Comment on "The biosphere: A homogeniser of Pb-isotope signals" by C. Reimann, B. Flem, A. Arnoldussen, P. Englmaier, T.E. Finne, F. Koller and Ø. Nordgulen
- 2008
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Ingår i: Applied Geochemistry. - : Elsevier BV. - 0883-2927. ; 23:8, s. 2519-2526
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Tidskriftsartikel (refereegranskat)abstract
- The paper by Reimann et al. (2008) is an echo of the debate carried out mainly by Clair Patterson and Robert Kehoe in the 1960s to 1980s about whether the enrichment of Pb in the biosphere and humans was a result of the global Pb contamination or due to natural causes and what impacts on human health were entailed ([Needleman, 1998] and [Nriagu, 1998]). Reimann et al. are also re-awakening the idea that the ‘plant pump’ is the reason for the surface enrichment of Pb in the soil (Goldschmidt, 1937). So is it time to revive this debate again? Are there reasons to expect that the enrichment of Pb and the change in Pb isotopic composition in surface soils is due to natural plant cycling and not due to the 1000-fold enrichment of Pb in the environment and humans since pristine times as originally suggested by Clair Patterson ([Patterson, 1965] and Settle and Patterson, 1980 D. Settle and C.C. Patterson, Lead in Albacore: guide to lead pollution in Americans, Science 207 (1980), pp. 1167–1176. View Record in Scopus | Cited By in Scopus (97)[Settle and Patterson, 1980])? Is it so that a changed plant uptake can explain the >90% reduction of Pb in mosses seen all over Europe since the 1970s, which co-occurs with reduced atmospheric emissions (e.g., [Berg and Steinnes, 1997a] and [Rühling and Tyler, 2001])? Is there a reason to believe that plants, independent of the geological matrix below choose to take up Pb with an isotopic composition that causes the surface organic layer all over Europe to have lower (i.e., heavier) 206Pb/207Pb ratios that are coincidentally similar to anthropogenic Pb sources? No, of course not. In this comment the author explains why he thinks future studies should not adopt the conclusions of Reimann et al.
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| 7. |
- Bindler, Richard, et al.
(författare)
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Landscape-scale patterns of sediment sulfur accumulation in Swedish lakes
- 2008
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Ingår i: Journal of Paleolimnology. - : Springer Science and Business Media LLC. - 0921-2728 .- 1573-0417. ; 39, s. 61-70
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Tidskriftsartikel (refereegranskat)abstract
- Sulfur has played a central role in the acidification of many lakes in Scandinavia and other regions. As part of the research into sulfur cycling, numerous studies have analyzed the sediment record in order to develop insights into past in-lake cycling of sulfur, particularly in the context of reconstructing past deposition rates. Although many of these studies have shown that it is not easy to interpret the sediment record in terms of past sulfur deposition rates, analyses of sulfur in sediment still provide valuable information on the response of lakes to anthropogenic sulfur deposition. Here, we have analyzed sulfur in top and bottom samples from short surface cores (25-35 cm, representing >= 250 years) as well as bulk cores from similar to 110 lakes located throughout Sweden, which were collected during 1986, as well as in more-detailed profiles from six lakes. The lakes with the highest surface sediment concentrations (9-24 mg S g(-1) dry mass) and the highest calculated inventories of 'excess' sulfur (20-180 g S m(-2)) are found in southern Sweden and around one industrial area along the northeastern coast where sulfur deposition rates and lake-water concentrations have been highest. For many lakes in the central and northern inland region it is common that the sediment cores exhibit either no enrichment or even a decline in sulfur concentrations in near-surface sediments, which we suggest was the pre-pollution norm for lakes. Although interpreting sulfur sediment profiles is problematic for reconstructing deposition, a more-comprehensive spatial sampling approach shows that there is a good geographic agreement between sulfur deposition, lake-water chemistry and sediment sulfur accumulation.
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| 8. |
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| 9. |
- Bindler, Richard, et al.
(författare)
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Widespread waterborne pollution in central Swedish lakes and the Baltic Sea from pre-industrial mining and metallurgy
- 2009
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 157, s. 2132-2141
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Tidskriftsartikel (refereegranskat)abstract
- Metal pollution is viewed as a modern problem that began in the 19th century and accelerated through the 20th century; however, in many parts of the globe this view is wrong. Here, we studied past waterborne metal pollution in lake sediments from the Bergslagen region in central Sweden, one of many historically important mining regions in Europe. With a focus on lead (including isotopes), we trace mining impacts from a local scale, through a 120-km-long river system draining into Malaren - Sweden’s third largest lake, and finally also the Baltic Sea. Comparison of sediment and peat records shows that pollution from Swedish mining was largely waterborne and that atmospheric deposition was dominated by long-range transport from other regions. Swedish ore lead is detectable from the 10th century, but the greatest impact occurred during the 16th-18th centuries with improvements occurring over recent centuries, i.e., historical pollution > modern industrial pollution.
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| 10. |
- Gälman, Veronika, et al.
(författare)
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Carbon and nitrogen loss rates during aging of lake sediment : Changes over 27 years studied in varved lake sediment
- 2008
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Ingår i: Limnology and Oceanography. - Waco, Tex. : American Society of Limnology and Oceanography. - 0024-3590 .- 1939-5590. ; 53:3, s. 1076-1082
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Tidskriftsartikel (refereegranskat)abstract
- We used a collection of ten freeze cores of annually laminated (varved) lake sediment from Nylandssjön in northern Sweden collected from 1979 to 2007 to follow the long-term loss of carbon (C) and nitrogen (N) due to processes that occur in the lake bottom as sediment ages. We compared specific years in the different cores. For example, the loss of C from the surface varve of the 1979 core (sediment deposited during 1978) was followed in the cores from 1980, 1985, 1989, and so on until 2006. The C concentration of the sediment decreased by 20% and N decreased by 30% within the first five years after deposition, and after 27 yr in the sediment, there was a 23% loss of C and 35% loss of N. Because the relative loss of C with time was smaller than loss of N, the C:N ratio increased with increasing age of the sediment; the surface varves start with a ratio of ~10, which then increases to ~12.
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