Comment on : “A novel approach to peatlands as archives of total cumulative spatial pollution loads from atmospheric deposition of airborne elements complementary to EMEP data: Priority pollutants (Pb, Cd, Hg)” by Ewa Miszczak, Sebastian Stefaniak, Adam Michczyński, Eiliv Steinnes and Irena Twardowska

Acknowledgements We are thankful to P.G. Appleby, R. Bindler, J. Sonke, B. Smieja-Krol and three anonymous reviewers for their constructive comments.Peer reviewedPostprin

Major and trace elements in Sphagnum moss from four southern German bogs, and comparison with available moss monitoring data

In this paper, we present concentrations of an array of major and trace elements (Ag, Al, As, Ba, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Rb, Sb, Sc, Sr, Th, Tl, U, V, Zn) in living Sphagnum mosses from four southern German bogs and compare them with moss monitoring data of the respective regions. To do this, Sphagnum mosses were collected in Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Surfaces of Sphagnum carpets were marked with plastic mesh and, one year later, the annual moss production was harvested. Up to 12 samples (40 cm × 40 cm) were collected per site, and 6–10 sites investigated per bog. The concentrations of these elements were then determined in acid digests using sector field ICP-MS. Variations within a given sampling site were in the range of 2 to 3-fold for all major and trace element concentrations except for Mn (12-fold) and Tl (38-fold). For most of the elements, concentrations between bogs of a given region were significantly different and atmospheric deposition of particles seems to be considerably affected by local circumstances such as tree canopy interception and microtopography. Comparing trace element concentrations measured in Sphagnum mosses for 2007 with published moss monitoring data for 2005 resulted in a very good agreement for most elements. Clearly, Sphagnum mosses from bogs are useful biomonitors for estimating atmospheric contamination by metals. This supports the use of Sphagnum in atmospheric deposition monitoring especially in cases where Sphagnum is abundant (e.g., boreal forests). In regions with neither bogs nor forests, living Sphagnum moss bags could be used to the same effect.JRC.G.II.6-Nuclear Safeguards and Forensic

Stable (206Pb, 207Pb, 208Pb) and radioactive (210Pb) lead isotopes in 1 year of growth of Sphagnum moss from four ombrotrophic bogs in southern Germany: geochemical significance and environmental implications

The surfaces of Sphagnum carpets were marked with plastic mesh and one year later the production of plant matter was harvested in four ombrotrophic bogs from two regions of southern Germany: Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Radioactive, 210Pb was determined in solid samples using ultralow background gamma spectrometry while total Pb concentrations and stable isotopes (206Pb, 207Pb, 208Pb) were determined in acid digests using ICP-SMS. Up to 12 samples (40x40 cm) were collected per site, and 6 to 10 sites investigated per bog. The greatest variations within a given sampling site were in the range 212-532 Bq kg-1 for 210Pb activity, whereas 206Pb/207Pb and 208Pb/206Pb varied less than 1 %. The median values of all parameters for the sites (6-10 per bog) were not significantly different. The median activities of 210Pb (Bq kg-1) in the mosses collected from the bogs in NBF (HO = 372 ± 56, n=55; WI = 342 ± 58, n=93) were slightly less from those in OB (GS = 394 ± 50, n=55; KL = 425 ± 58, n=24). However, the mosses in the NBF bogs exhibited much greater productivity (187 to 202 g m-2 a-1) compared to those of OB (71 to 91 g m-2 a-1), and this has a profound impact on the accumulation rates of 210Pb (Bq m-2 a-1), with the bogs in the NBF yielding fluxes (HO = 73 ± 30; WI = 65 ± 20) which are twice those of OB (GS = 29 ± 11; KL = 40 ± 13). Using the air concentrations of 210Pb measured at Schauinsland (SIL) in the southern Black Forest and average annual precipitation, the atmospheric fluxes of 210Pb at SIL (340 Bq m-2 a-1) exceeds the corresponding values obtained from the mosses by a factor of five, providing the first quantitative estimate of the retention efficiency of 210Pb by Sphagnum. When the 210Pb activities of all moss samples are combined (n=227), a significant decrease with increasing plant production rate is observed; in contrast, total Pb concentrations show the opposite trend. The contrasting behaviour of 210Pb and total Pb in the mosses may reflect differences in the particle size distribution of the corresponding aerosols, their physical and chemical properties, the extent of their interaction with plant surfaces, or some combination of these factors. The 206Pb/207Pb ratios from NBF (HO = 1.159 ± 0.002, n=19; WI = 1.157 ± 0.003, n=48) and OB (GS = 1.157± 0.003, n=28; KL = 1.159 ± 0.003, n=15) are uniform, indicating that both regions are impacted by Pb from predominately anthropogenic sources. Although Sphagnum moss represents an established receptor in monitoring atmospheric Pb deposition, the physical characteristics (size, morphology, composition) of the three predominant kinds of Pb-bearing aerosols considered here, namely 210Pb (adsorbed onto aerosol surfaces, following decay of 222Rn), anthropogenic Pb (sub-micron aerosols from high temperature combustion processes) and soilderived mineral dusts (tens of microns, from chemical weathering of crustal rocks), are fundamentally different and these have consequences for the retention efficiency of the three kinds of particles.JRC.E.5-Nuclear chemistr

Validating modelled data on major and trace element deposition in southern Germany using Sphagnum moss

Sphagnum mosses were collected from four ombrotrophic bogs in two regions of southern Germany: Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Surfaces of Sphagnum carpets were marked with plastic mesh and, one year later, plant matter was harvested and productivity determined. Major and trace element concentrations (Ag, Al, As, Ba, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Pb, Rb, Sb, Sc, Sr, Th, Ti, Tl, U, V, Zn) were determined in acid digests using sector field ICP-MS. Up to 12 samples (40 × 40 cm) were collected per site, and 6–10 sites investigated per bog. Variation in element accumulation rates within a bog is mostly the result of the annual production rate of the Sphagnum mosses which masks not only the impact of site effects, such as microtopography and the presence of dwarf trees, but also local and regional conditions, including land use in the surrounding area, topography, etc. The difference in productivity between peat bogs results in distinctly higher element accumulation rates at the NBF bogs compared to those from OB for all studied elements. The comparison with the European Monitoring and Evaluation Program (EMEP; wet-only and total deposition) and Modelling of Air Pollutants and Ecosystem Impact (MAPESI; total deposition) data shows that accumulation rates obtained using Sphagnum are in the same range of published values for direct measurements of atmospheric deposition of As, Cd, Cu, Co, Pb, and V in both regions. The accordance is very dependent on how atmospheric deposition rates were obtained, as different models to calculate the deposition rates may yield different fluxes even for the same region. In future studies of atmospheric deposition of trace metals, both Sphagnum moss and deposition collectors have to be used on the same peat bog and results compared. Antimony, however, shows considerable discrepancy, because it is either under-estimated by Sphagnum moss or over-estimated by both atmospheric deposition models. Atmospheric deposition data obtained from sampling in open fields is unlikely to always perfectly match data obtained using living Sphagnum moss from bogs. In fact, plant uptake and biochemical utilization by living moss may affect accumulation rates of those elements that are essential for plant nutrition (macro and micronutrients), which is clearly seen in the data presented here for Mn, Fe and Zn. Furthermore, Sphagnum moss is a unique receptor, with its characteristic roughness and chemical complexity. These two aspects, combined with conditions found on the bog surface (variations in microtopography, shrubs, trees, wetness, snow cover, etc.), result in a unique type of interception and retention. Despite all these factors, the comparison with modelled data shows that Sphagnum moss is a good indicator of atmospheric deposition at least in a semi-quantitative manner and certainly reflects inputs to terrestrial ecosystems.JRC.G.II.6-Nuclear Safeguards and Forensic

Detection of KHV in Freshwater Mussels and Crustaceans from Ponds with KHV History in Common Carp (Cyprinus carpio)

Characterization of asymptomatic KHV carriers may help understand virus transmission and storage. Such information allows farmers to minimize KHV on farms where this virus is present, also in common carp (Cyprinus carpio) monocultures. As asymptomatic KHV carriers, freshwater mollusks from the Unionidae family (swan mussels, Anodonta cygnea) and crustaceans from the Gammaridae family (scud, Gammarus pulex) were studied because of their unique method of feeding by accumulating bacterial and viral particles. The KHV genome was detected by nested PCR and confirmed by PCR recognizing the KHV glycoprotein gene in ORF 56 (KHV-U). Both PCR and nested PCR, which recognize the KHV thymidine kinase gene, always produced negative results in the swan mussels and scud samples

Sphagnum Moss in the Athabasca Bituminous Sands Region Reveals No Significant Atmospheric Contamination by "Heavy Metals"

Sphagnum moss were collected from three sites at each of twenty-one ombrotrophic (rain-fed) peat bogs in the vicinity of and surrounding open pit mines and upgrading facilities of Athabasca Bituminous Sands in Alberta. Compared with contemporary Sphagnum moss from multiple sites at each of four bogs in rural locations of southern Germany, the AB mosses yielded lower concentrations of Ag, Cd, Ni, Pb, Sb and Tl, similar concentrations of Mo, but greater concentrations of Ba, Th and V. Compared to the “cleanest”, ancient peat samples ever tested from the northern hemisphere and dating from the mid-Holocene (ca. 6,000 to 9,000 years old), with the exception of V, the concentrations of each of these metals in the AB mosses are within a factor of three of “natural, background” values. The concentrations of “heavy metals” in the mosses are proportional to the concentration of Th (a conservative, lithogenic element) and therefore are contributed to the plants primarily in the form of mineral dust particles. Although it has been claimed that bitumen mining is a significant source of atmospheric Pb contamination, compared with the surface layer (1 cm slice) of peat cores collected in recent years from across Canada (13 cores in five Provinces from British Columbia to New Brunswick), the Pb concentrations in the mosses from AB are far lower. Vanadium, the single most abundant trace metal in bitumen, is the only exception: on average V in the AB mosses exceeds that of ancient peat by a factor of six; it is therefore enriched in the mosses, relative to Th, by a factor of two.JRC.E.5-Nuclear chemistr

Response to Comment on "Sphagnum Mosses from 21 Ombrotrophic Bogs in the Athabasca Bituminous Sands Region Show no Significant Atmospheric Contamination of “Heavy Metals”"

Blais and Donahue (2015) draw attention to many contemporary environmental issues and concerns regarding the industrial development of the Athabasca Bituminous Sands (ABS), most of which are outside of the scope of our original study (Shotyk et al., 2014). Here we restrict our response to the remarks they made which actually apply to our paper. The focus of our paper was the abundance and spatial variation in concentrations of “heavy metals” (selected chalcophile elements namely Ag, Cd, Pb, Sb, and Tl) as well as V, Ni and Mo (the three elements which are well known to be enriched in bitumen). We compared the concentrations of these elements in Sphagnum moss with those of Th, a conservative, lithophile element which was taken to reflect the abundance of mineral dust particles in the mosses. Concern was expressed by Blais and Donahue for our analysis and interpretation, in particular the use of average concentrations for each sampling location, the variation in metal concentrations with distance from industry, and the contribution of mineral dust particles to the heavy metal concentrations.JRC.E.5-Nuclear chemistr

Sphagnum Mosses from 21 Ombrotrophic Bogs in the Athabasca Bituminous Sands Region Show No Significant Atmospheric Contamination of “Heavy Metals”

Sphagnum moss was collected from 21 ombrotrophic (rain-fed) peat bogs surrounding open pit mines and upgrading facilities of Athabasca bituminous sands in Alberta (AB). In comparison to contemporary Sphagnum moss from four bogs in rural locations of southern Germany (DE), the AB mosses yielded lower concentrations of Ag, Cd, Ni, Pb, Sb, and Tl, similar concentrations of Mo, but greater concentrations of Ba, Th, and V. Except for V, in comparison to the “cleanest”, ancient peat samples ever tested from the northern hemisphere (ca. 6000–9000 years old), the concentrations of each of these metals in the AB mosses are within a factor of 3 of “natural, background” values. The concentrations of “heavy metals” in the mosses, however, are proportional to the concentration of Th (a conservative, lithophile element) and, therefore, contributed to the plants primarily in the form of mineral dust particles. Vanadium, the single most abundant trace metal in bitumen, is the only anomaly: in the AB mosses, V exceeds that of ancient peat by a factor of 6; it is therefore enriched in the mosses, relative to Th, by a factor of 2. In comparison to the surface layer of peat cores collected in recent years from across Canada, from British Columbia to New Brunswick, the Pb concentrations in the mosses from AB are far lower