Jörg Matschullat

Arsenic in the geosphere — a review

An attempt is made to quantify the global element cycle for arsenic, based on an extensive literature research with special emphasis on the most recent works. Reservoirs in and fluxes within and through lithosphere, atmosphere, pedosphere, hydrosphere, biosphere, and anthrosposphere are being presented. Crucial knowledge gaps are addressed and some simple model calculations partially question currently held ideas about sources, pathways, and the fate of arsenic in the environment.

Soil and sediment geochemistry of the iron quadrangle, Brazil the case of arsenic

Soils and sediments around gold ore deposit and mining sites in the Iron Quadrangle present positive As anomalies (median concentrations > 100 mg kg-1) and wide ranges (< 20 to > 2000 mg kg-1) even in densely populated areas. These anomalies can be related to geological structures, to hydrothermal ore deposits and to their continuous exploitation over the past three centuries. The paper presents new data on both As geochemistry and soil and sediment geochemistry in general, and discusses consequences of the encountered anomalies, their reasons and potential effects and how they compare with current screening and threshold values. While surface soil As-values are reproducible at a given site, sediment anomalies show a strong seasonal variation that can be explained by tropical hydrological variances. Suggestions are presented on how to minimize the As-load in densely populated areas that might otherwise pose a potential health risk.

Aerosol and bulk deposition trends in the 1990's, Eastern Erzgebirge, Central Europe.

Abstract Atmospheric aerosols were collected in the Eastern Erzgebirge, Germany, and a multi-element survey was carried out by PIXE, INAA, and GF-AAS for samples from 1992–1994 and 1996–1997 (Al, As, Ba, Br, Ca, Cl, Cr, Cu, Fe, Ga, Ge, I, In, K, Mg, Mn, Na, Ni, P, Pb, S, Se, Si, Sr, Ti, V, Zn). For comparison, new bulk deposition data for open field and canopy throughfall stations are presented from the same area (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Cl − , Co, Cr, Cu, F − , Fe, Ga, Ge, I, In, K, Mg, Mn, Mo, NO 3 − , Na, Ni, Pb, PO 4 2− , Rb, SO 4 2− , Sb, Se, Sn, Sr, Th, Ti, Tl, U, V, Y, Zn, Zr). The most prominent result is that emission control in Central Europe is taking effect. The concentrations of many anthropogenic constituents in both bulk deposition and in aerosols today have declined considerably. In the formerly highly polluted Eastern Erzgebirge, deposition can now be addressed as comparable to rural areas without major local or regional influences.

Determination of arsenic species in human urine using high performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS)

A speciation technique for arsenic (As) has been applied using ion pair reverse phase-high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (RP-HPLC-ICP-MS). Six As-species (arsenite, arsenate, dimethylarsinic acid, dimethylarsinous acid, monomethylarsonic acid and monomethylarsonous acid) have been separated with isocratic elution within less than 6 minutes. A cation exchange column was used for separation of AsB, AsC, Tetra (Me4As+) and TMAsO. The As chemical form and oxidation state is highly important in respect to toxicity; therefore total As-determination is insufficient for a complete toxicological evaluation and risk assessment. Arsenic-speciation has been studied on urine samples of children from an As-affected area in the Iron Quadrangle, Brazil. DMAsV and MMAsV were the major urinary metabolites in these samples. The mean value for total As-concentration of all samples (n = 15) was 26.3 ng As mL−1 with a range of 16.1 to 55.2 ng As mL−1. TMAsO and AsC (arsenocholine) were not detected in this study. In most samples, monomethylarsonous acid [MMAsIII] was detected up to 2.0 ng As mL−1. DMAsIII was not detected at any time, most probably due to volatilisation and some oxidation to DMAsV. The chromatographic recoveries, calculated from ([sum(species) × 100]/total As in urine samples), ranged from 77.4 to 94.9%. This work also contributes to the pertinent discussion regarding the reliability of MMAsIII/DMAsIII speciation in urine.

Overbank sediment profiles : evidence of early mining and smelting activities in the Harz mountains, Germany

Abstract Two overbank sediment cores to a depth of 5.6 m and 2.3 m respectively from the Uferbach catchment on the western foothills of the Harz mountains, Lower Saxony, Germany, revealed two anomalies of Pb, Zn, and Cu at 30–130 cm and at 204 cm, a Pb Zn-anomaly at 280 cm and a Pb-anomaly at 410 cm—evidence of four phases of mining and smelting activities in the catchment. The geochemical (major, minor, and trace elements) and mineralogical investigations (microscopy and microprobe analysis of matrix and slag particles) allowed for a broad interpretation of the element behavior (e.g., landuse) and the source region of the processed ore (hydrothermal deposits of the Upper Harz). A simple calculation model, based on 14 C-data, helped to estimate the time frame for the anomalies. The most likely interpretation requires an increase of the sedimentation rates over time (from 1 to 4 mm a −1 ) and suggests medieval (1140–1345 A.D.), karolingian (82–890 AD), roman-germanic (425–500 A.D.) and early historic (825–625 B.C.) phases of smelting activities.

Assessing vegetation variability and trends in north-eastern Brazil using AVHRR and MODIS NDVI time series

Abstract Desertification is a challenge in north-eastern Brazil (NEB) that needs to be understood to develop sustainable land-use strategies. This study analyses regional vegetation dynamics in NEB and the compatibility of two NDVI data sets to support future desertification assessment studies in the semi-arid Caatinga biome. Vegetation variability and trends in NEB are analysed for 1982–2006, based on monthly AVHRR (GIMMS) NDVI data. The GIMMS data are compared with MODIS NDVI for the overlapping period 2001–2006. Existing statistical methods are applied and existing NDVI analyses in NEB expanded in respect to vegetation trend analysis and data set comparison.

Hydromorphological assessment within the EU-Water Framework Directive—trans-boundary cooperation and application to different water basins

Many water authorities face the challenge to comply with WFD criteria. Overview survey methods are faster and more economic compared to more intensive field surveys. This work tests the quality of both approaches, with a focus on the hydromorphological status assessment. First, WFD criteria and descriptions for hydromorphological quality components and monitoring demands are summarized. A practical assessment of hydromorphological features follows, performed in German and Czech sub-catchments of the Elbe River. Three different methods of stream habitat survey were applied, two German field and overview survey standards by LAWA (Weisseritz basin), and a new Czech field survey method EcoRivHab (Rolava basin). Comparability of results and suitability to fulfil the WFD and CEN standard requirements were tested. Results show that the field and overview survey methods are non-interchangeable and irreplaceable. The overview method provides good results when conditions of large areas need to be evaluated but results seem to overestimate the true quality of the aquatic ecosystem. The field survey methods provide more accurate information. Both field survey methods (LAWA and EcoRivHab) offer good results on hydromorphological river characteristics, evaluated by a point system. Both methods are powerful in evaluating riparian belts and floodplain hydromorphology. The relative added effort of field mapping is overcompensated by the quality of the outputs, which are fully compatible with the aims of the WFD.

Experimental degradation of polymer shopping bags (standard and degradable plastic, and biodegradable) in the gastrointestinal fluids of sea turtles

The persistence of marine debris such as discarded polymer bags has become globally an increasing hazard to marine life. To date, over 177 marine species have been recorded to ingest man-made polymers that cause life-threatening complications such as gut impaction and perforation. This study set out to test the decay characteristics of three common types of shopping bag polymers in sea turtle gastrointestinal fluids (GIF): standard and degradable plastic, and biodegradable. Fluids were obtained from the stomachs, small intestines and large intestines of a freshly dead Green turtle (Chelonia mydas) and a Loggerhead turtle (Caretta caretta). Controls were carried out with salt and freshwater. The degradation rate was measured over 49 days, based on mass loss. Degradation rates of the standard and the degradable plastic bags after 49 days across all treatments and controls were negligible. The biodegradable bags showed mass losses between 3 and 9%. This was a much slower rate than reported by the manufacturers in an industrial composting situation (100% in 49 days). The GIF of the herbivorous Green turtle showed an increased capacity to break down the biodegradable polymer relative to the carnivorous Loggerhead, but at a much lower rate than digestion of natural vegetative matter. While the breakdown rate of biodegradable polymers in the intestinal fluids of sea turtles is greater than standard and degradable plastics, it is proposed that this is not rapid enough to prevent morbidity. Further study is recommended to investigate the speed at which biodegradable polymers decompose outside of industrial composting situations, and their durability in marine and freshwater systems.

Lake ice phenology in Berlin-Brandenburg from 1947–2007: observations and model hindcasts

Rising northern hemispheric mean air temperatures reduce the amount of winter lake ice. These changes in lake ice cover must be understood in terms of resulting effects on lake ecosystems. Accurate predictions of lake ice phenology are essential to assess resulting impact. We applied the one-dimensional physical lake model FLake to analyse past variability in ice cover timing, intensity and duration of Berlin-Brandenburg lakes. The observed ice phenology in two lakes in the period 1961–2007 was reconstructed by FLake reasonably well and with higher accuracy than by state-of-the-art linear regression models. Additional modelling results of FLake for 38 Berlin-Brandenburg lakes, observed in the winter of 2008/09, were quite satisfactory and adequately reproduced the effects of varying lake morphology and trophic state. Observations and model results showed that deeper and clearer lakes had more ice-free winters, later ice cover freezing and earlier ice cover thawing dates, resulting in shorter ice-covered periods and fewer ice-covered days than shallow and less clear lakes. The 1947–2007 model hindcasts were implemented using FLake for eight Berlin-Brandenburg lakes without ice phenology observations. Results demonstrated past trends of later ice start and earlier ice end, shorter ice cover duration and an increase in ice-free winters.

Regional and temporal (1992–2004) evolution of air-borne sulphur isotope composition in Saxony, southeastern Germany, central Europe†

The isotopic composition of air-borne sulphur was investigated in Saxony, Southeast Germany – a region with formerly very high atmospheric SO2 concentrations. In addition, data from various authors were compiled for different Saxonian locations, spanning from 1992 to 2004, i.e., a time of decreasing SO2 concentrations in the atmosphere. There were no obvious temporal changes in the mean δ34S value of bulk precipitation. However, the variability of monthly mean δ34S values decreased. The mean sulphur isotope composition of sulphate from bulk precipitation after the year 2000 converges in Saxony towards 4–5‰, with similar values for different locations. Mean values of different forms of sulphur show the following enrichment order: δ34S of SO2 < δ34S of weathering crusts ≤δ34S of sulphate from bulk precipitation ≤δ34S of dust. Judging from local differences on sulphate crusts and corresponding isotope values of sources, the δ34S value of SO2 as well as for crusts mainly reflects local point sources. The mean δ34S value of bulk precipitation represents more regionally well-mixed SO2 sources and is therefore an ideal tool for monitoring regional atmospheric change. †Revised version of a paper presented at the 27th Annual Meeting of the German Association for Stable Isotope Research (GASIR), October, 4–6, 2006, Freiberg, Germany.