Cadmium contents of vertically and horizontally deposited winter precipitation in Central Europe: Spatial distribution and long-term trends

Cadmium (Cd) and its forms has recently been a focus of attention due to its toxic effects on human health and the environment. We evaluated the atmospheric deposition of Cd during three consecutive winter seasons (2009-2011) at 10 mountain-top locations in the Czech Republic along the borders with Poland, Germany, Austria and Slovakia. Cadmium concentrations of soluble and insoluble forms in both horizontal (rime) and vertical (snow) deposition were determined using sector-field ICP-MS. Across the sites, 94% of the total winter Cd deposition occurred in the soluble (bioavailable/environmental available) Cd form. Mean concentrations of soluble Cd in rime were six times higher than in snow (398 vs. 66 ng L-1). Vertical deposition contributed as much as 41% to the total winter Cd input. Significant among-site variability in winter Cd deposition ranged between 13 and 108 g m-2 winter-1. Overall, Cd concentrations in winter deposition did not reach legislated drinking water limits and did not pose a direct threat for human health. Long-term trends (1996-2017) in winter Cd deposition were evaluated using six GEOMON sites (a monitoring network of small forested catchments). Since 1996, Cd input in winter atmospheric deposition was reduced by 73-93%. Simultaneously, we found declines in among-site variability in winter Cd inputs. The highest recent winter Cd inputs were found at sites in the northeast of the country. A north-south pollution gradient, which has frequently been mentioned in the literature, was not observed, with both northwest sites and southern sites among those with the lowest Cd pollution. Backward trajectories of the HYSPLIT model for fresh snow samples identified Poland and Germany as major transboundary Cd pollution sources for the Czech Republic.JRC.G.II.6-Nuclear Safeguards and Forensic

Increasing Arsenic Concentrations in Runoff from 12 Small Forested Catchments (Czech Republic, Central Europe): Patterns and Controls

The 40-year period of heavy industrialization in Central Europe (1950-1990) was accompanied by massive burning of arsenic-rich lignite in power plants. Absence of effective dust removal devices in power plants led to substantial accumulation of arsenic in ecosystems, mainly in forest soils. There are fears that retreating acidification in spruce die-back affected areas of southeastern Germany, northern Czech Republic and southern Poland (the Black Triangle) may lead to arsenic mobilization into drinking water, caused by competitive ligand exchange. We present monthly arsenic concentrations in surface runoff from 12 headwater catchments in the Czech Republic for a period of 13 years (1996-2008). The area covering 75,000 km2 was characterized by a north-south gradient of decreasing pollution. Acidification has been retreating since the late 1980s. Between 1996 and 2003, maximum arsenic concentrations in stream water did not change, and were < 1 ppm in the rural south and < 2 ppm in the industrial north of the country. During the subsequent two years, 2004-2005, maximum arsenic concentrations in runoff increased in 11 of the 12 catchments, reaching 60% of the drinking water limit (10 ppm). Starting in 2006, another major change occurred. Maximum arsenic concentrations returned to lower values at most sites. We discuss three possible causes of the recent arsenic concentration maximum in streams. We rule out retreating acidification and a pulse of high industrial emission rates as possible controls. The pH of stream water has not changed since 1996, and is still too low (<6.5) at most sites for an As¿OH- ligand exchange to become significant. Elevated arsenic concentrations in runoff in 2004-2005 may reflect climate change through changing hydrological conditions at some, but not all, sites. A wet year 2002 was followed by a dry year 2003 just before the high-arsenic period in runoff at 6 sites.JRC.E.5-Nuclear chemistr

Atmospheric deposition of beryllium in Central Europe: Comparison of soluble and insoluble fractions in rime and snow across a pollution gradient

Little is known about atmospheric input of beryllium (Be) into ecosystems, despite its highly toxic behavior. For 35 three consecutive winters (2009–2011), we measured Be concentrations in horizontal deposition (rime) and 36 vertical deposition (snow) at 10 remotemountain-top locations in the Czech Republic, Central Europe. Beryllium 37 was determined both in filtered waters, and in HF digests of insoluble particles. Across the sites, soluble Be 38 concentrations in rime were 7 times higher, compared to snow (6.1 vs. 0.9 ng·L 39 −1). Rime scavenged the pollution-rich lower segments of clouds. The lowest Be concentrations were detected in the soluble fraction of 40 snow. Across the sites, 34% of total Be deposition occurred in the form of soluble (bioavailable) Be, the rest 41 were insoluble particles. Beryllium fluxes decreased in the order: vertical dry deposition insoluble>vertical 42 dry deposition soluble>horizontal deposition soluble>vertical wet deposition insoluble>vertical wet deposi- 43 tion soluble>horizontal deposition insoluble. The average contributions of these Be forms to total deposition 44 were 56, 21, 8, 7, 5 and 3%, respectively. Sites in the northeastweremore Be-polluted than the rest of the country 45 with sources of pollution in industrial Silesia.JRC.E.5-Nuclear chemistr

Zinc isotope systematics in snow and ice accretions in Central European mountains

Zinc (Zn) pollution negatively affects human and ecosystem health. We quantified atmospheric Zn inputs at six remote mountain-top locations in the Czech Republic (Central Europe), and used δ66Zn isotope ratios to identify Zn from different pollution sources. The study sites were located at an elevation of approximately 1000 m near the state borders with Germany and Poland. During two winter seasons (2009-2010), over 400 samples of vertical deposition (snow) and horizontal deposition (ice accretions) were collected. Zinc pollution levels were generally low. Zinc concentrations in snow and ice accretions were less than twice higher in the east, compared to the west. Across the sites, over 90 % of Zn was present in a weak-acid soluble form. Zinc concentrations were 5 times higher in ice accretions, which formed from small droplets originating in the basal cloud layer, rich in pollutants, than in snow. In contrast, droplets resulting in snow formation were larger and scavenged less pollution due to their smaller surface area. δ66Zn of Pribram sphalerite (west) and smelter-derived fly ash (west) were low, -0.23 and -0.47 ‰, respectively. Olkusz sphalerite (east) had a higher δ66Zn of 0.02 ‰. δ66Zn of snow ranged from -0.60 to 0.68 ‰. Ice accretions had δ66Zn between - 0.67 and 0.14 ‰. At the three eastern sites, δ66Zn of ice accretions were lower than δ66Zn of snow, suggesting the presence of volatilized smelter derived or coal-burning derived Zn. δ66Zn of ice accretions at two of the three western sites were higher than δ66Zn of snow. Different δ66Zn values of snow and ice accretions from the same site reflected different pollution sources, which may have been situated at different distances from the receptor site. δ66Zn of the soluble Zn fraction was higher than δ66Zn of the insoluble Zn fraction, possibly also indicating a different origin of these two Zn fractions. Zinc isotope heterogeneity in the atmosphere of remote areas indicates that δ66Zn can be a useful tool in pollution provenance studies.JRC.E.5-Nuclear chemistr