Quantitative determination of minerals and anthropogenic particles in some Polish peat occurrences using a novel SEM point-counting method

A method is proposed for determining the mineral composition of peat using scanning electron microscope. In an illustrative example, five groups of particles occurring in amounts of >0.05 % are distinguished in peat from Puścizna Mała bog in the Carpathian foreland, Poland. These are spheroidal aluminosilicate particles (SAP), feldspars, nondescript aluminosilicates (mainly clays), silica (quartz and opaline silica), and Fe(hydro)oxides. Two more site-specific groups (barite and ZnS) are distinguished in highly polluted fens (Bagno Bruch and Bagno Mikołeska) near a zinc smelter in Upper Silesia. At Bagno Bruch, peat contents of predominantly authigenic ZnS microspheroids range up to 1.1 %. SAP originating from coal-burning power stations account for maximum concentrations of <21–39 % of the inorganic fraction in the studied mires. SAP concentrations vary with depth, and mean spheroid diameters with distance from emission sources. A distinct feature of SAP is their common enrichment in Ti what questions the use of Ti as a proxy for soil dust in fly ash polluted bogs. As amounts of anthropogenic magnetic spherules, less abundant than SAP in all mires, relate to water table level position, they are unsuitable as tracers of air pollution. The proposed method is recommended for application with peats having ash contents > ~4 %

Pseudomorphs of barite and biogenic ZnS after phyto-crystals of calcium oxalate (whewellite) in the peat layer of a poor fen

Pseudomorphs of barite (BaSO(4)) and Cd-rich ZnS after whewellite (CaC(2)O(4)·H(2)O) occur within remnants of Scots pine bark tissues in the peat layer of a poor fen located near a zinc smelter in south Poland. A two-step formation of the pseudomorphs is postulated based on SEM observations: (1) complete dissolution of whewellite, possibly caused by oxalotrophic bacteria, and (2) subsequent bacterially induced precipitation of barite and spheroidal aggregates of ZnS together with galena (PbS) in voids left by the dissolved whewellite crystals. Local increase in pH due to microbial degradation of whewellite, elevated concentrations of Zn(II) and Ba(II) in pore water due to the decomposition of atmospheric particles of sphalerite and barite in the acidic (pH 3.5–3.8) environment, oxidation of S species during drying and rewetting of the peat layer, and subsequent partial reduction of sulfate anions by sulfur-reducing bacteria were all factors likely involved in the crystallization of ZnS and barite in the microenvironment of the post-whewellite voids

The impact of ambient atmospheric mineral-dust particles on the calcification of lungs

For the first time, it is shown that inhaled ambient air-dust particles settled in the human lower respiratory tract induce lung calcification. Chemical and mineral compositions of pulmonary calcium precipitates in the lung right lower-lobe (RLL) tissues of 12 individuals who lived in the Upper Silesia conurbation in Poland and who had died from causes not related to a lung disorder were determined by transmission and scanning electron microscopy. Whereas calcium salts in lungs are usually reported as phosphates, calcium salts precipitated in the studied RLL tissue were almost exclusively carbonates, specifically Mg-calcite and calcite. These constituted 37% of the 1652 mineral particles examined. Mg-calcite predominated in the submicrometer size range, with a MgCO3 content up to 50 mol %. Magnesium plays a significant role in lung mineralization, a fact so far overlooked. The calcium phosphate (hydroxyapatite) content in the studied RLL tissue was negligible. The predominance of carbonates is explained by the increased CO2 fugacity in the RLL. Carbonates enveloped inhaled mineral-dust particles, including uranium-bearing oxides, quartz, aluminosilicates, and metal sulfides. Three possible pathways for the carbonates precipitation on the dust particles are postulated: (1) precipitation of amorphous calcium carbonate (ACC), followed by its transformation to calcite; (2) precipitation of Mg-ACC, followed by its transformation to Mg-calcite; (3) precipitation of Mg-free ACC, causing a localized relative enrichment in Mg ions and subsequent heterogeneous nucleation and crystal growth of Mg-calcite. The actual number of inhaled dust particles may be significantly greater than was observed because of the masking effect of the carbonate coatings. There is no simple correlation between smoking habit and lung calcification

Heavy metal accumulation in two peat bogs from Southern Poland

The dynamic changes in selected heavy metal concentrations were analyzed in two ombrotrophic peat bogs from southern Poland: Puścizna Mała (PK) and Puścizna Krauszowska (PM). The highest contents of Pb and Zn occur at the top of profiles examined: 115.36 mg/kg (PM1), 90.61 mg/kg (PM2), 182.40 mg/kg (PK1), 121.68 mg/kg (PK2) and 127.43 mg/kg (PM1), 89.73 mg/kg (PM2), 170 mg/kg (PK1), 130.4 mg/kg (PK2), respectively. Concentrations of copper are similar to those of local soils varying from 9.4 to 12.8 mg/kg. Cadmium strongly varies with depth, which indicates distinct mobility of this element. Two peaks of elevated Fe concentrations are observed at the top and bottom of the Puścizna Mała profile, while the maximum in Puścizna Krauszowska was at the top of the peat bog. The Ti content distinctly varies with depth and correlates with the ash content (R2 = 0.91-0.99). The strongest and positive correlation is observed between Zn-Pb and Ti-Pb contents. The significant differences of metal concentrations are noted between the profiles, which is probably connected with a rate of peat accumulation and plant composition of the profiles investigated, as well as with their disturbance by human activity

Geographical drivers of geochemical and mineralogical evolution of Motianling peatland (Northeast China) exposed to different sources of rare earth elements and Pb, Nd, and Sr isotopes

Geochemical shifts triggered by surface runoff and atmospheric fallout in a Chinese peatland were investigated by using Pb, Sr, and Nd, REE and by SEMmineralogical analysis.Motianling peatland (Northeast China) is located at 1670ma.s.l., near the China–Mongolia border. Based on division of profile into two phases of different trophy, the totalΣREE value determined for the minerotrophic part of the profile (from 62 to 46 cm) varied from 67 to 31 mg·kg−1 and mineralogical analysis revealed the occurrence ofweathered volcanic rocks, supported by a high εNd value (−3.26). After the transition from minerotrophic to more ombrotrophic conditions, the peatland became independent of the local bedrock weathering, which was manifested by a much lower concentration of REE (7–20 mg·kg−1) and lower εNd values (−7.37; −8.11). Moreover, PAAS-normalized pattern of REE distribution in the bottom part revealed the highest Eu/Eu* value (1.24), as well as a slight enrichment in Eu. The anthropogenic effect was visible from 1964, during which period the spheroidal aluminosilicate particles (SAP), produced by coal-fired power-plant activity, appeared for the first time, followed by an abrupt decrease in 206Pb/207Pb isotopic signature to 1.167. The dimensions of SAP (~1.5 μm), as well as the time of first appearance, indicated long-range transport. The REE ratios obtained in this study are characteristic of the eolian deposition signature, which is like the Gobi and northern Chinese deserts. The anthropogenic activity was manifested by a slight enrichment in Gd during reduced delivery of natural dust. Both, North Chinese and Asian part of the Russian industry supply anthropogenic dust. Topography, wind direction, and patterns of precipitation, as well as the initial phases of Asian industrial development, are the most important drivers promoting the deposition of chemical elements

SPRINGS WITH CALCAREOUS TUFA IN THE VALLEY OF THE JAMNE CREEK IN GORCE

The study gives a detail characteristic of a hard water springs habitat with the communities of Cratoneurion commutati (habitat code of Nature 2000: 7220), localized within Nature 2000 protected area Ostoja Gorczańska PLH120018, in an upper part of the valley of Jamne creek. The plants are described along with the main habitat parameters, namely: altitude, exposition, slope gradient, insolation, type of bedrock, water flow regime and the spring outflow efficiency. The temperature, pH, electrical conductivity were measured in the field, the concentrations of Ca and Mg in spring water were measured by Atomic Absorption Spectroscopy (AAS). The investigated headwater areas are small (0.7–80 m2) and highly differentiated by the intensity of calcareous tufa precipitation and the degree of plant cover development

Peatland microbial communities as indicators of the extreme atmospheric dust deposition

We investigated a peat profile from the Izery Mountains, located within the so-called Black Triangle, the border area of Poland, Czech Republic, and Germany. This peatland suffered from an extreme atmospheric pollution during the last 50 years, which created an exceptional natural experiment to examine the impact of pollution on peatland microbes. Testate amoebae (TA), Centropyxis aerophila and Phryganella acropodia, were distinguished as a proxy of atmospheric pollution caused by extensive brown coal combustion. We recorded a decline of mixotrophic TA and development of agglutinated taxa as a response for the extreme concentration of Al (30 g kg−1) and Cu (96 mg kg−1) as well as the extreme amount of fly ash particles determined by scanning electron microscopy (SEM) analysis, which were used by TA for shell construction. Titanium (5.9 %), aluminum (4.7 %), and chromium (4.2 %) significantly explained the highest percentage of the variance in TA data. Elements such as Al, Ti, Cr, Ni, and Cu were highly correlated (r>0.7, p<0.01) with pseudostome position/body size ratio and pseudostome position. Changes in the community structure, functional diversity, and mechanisms of shell construction were recognized as the indicators of dust pollution. We strengthen the importance of the TA as the bioindicators of the recent atmospheric pollution

Anthropogenic- and natural sources of dust in peatland during the Anthropocene

As human impact have been increasing strongly over the last decades, it is crucial to distinguish human-induced dust sources from natural ones in order to define the boundary of a newly proposed epoch - the Anthropocene. Here, we track anthropogenic signatures and natural geochemical anomalies in the Mukhrino peatland, Western Siberia. Human activity was recorded there from cal AD 1958 (±6). Anthropogenic spheroidal aluminosilicates clearly identify the beginning of industrial development and are proposed as a new indicator of the Anthropocene. In cal AD 1963 (±5), greatly elevated dust deposition and an increase in REE serve to show that the geochemistry of elements in the peat can be evidence of nuclear weapon testing; such constituted an enormous force blowing soil dust into the atmosphere. Among the natural dust sources, minor signals of dryness and of the Tunguska cosmic body (TCB) impact were noted. The TCB impact was indirectly confirmed by an unusual occurrence of mullite in the pea