Jarosław Sikorski

Anthropogenic impacts in North Poland over the last 1300 years - a record of Pb, Zn, Cu, Ni and S in an ombrotrophic peat bog.

Lead pollution history over Northern Poland was reconstructed for the last ca. 1300 years using the elemental and Pb isotope geochemistry of a dated Polish peat bog. The data show that Polish Pb-Zn ores and coal were the main sources of Pb, other heavy metals and S over Northern Poland up until the industrial revolution. After review of the potential mobility of each element, most of the historical interpretation was based on Pb and Pb isotopes, the other chemical elements (Zn, Cu, Ni, S) being considered secondary indicators of pollution. During the last century, leaded gasoline also contributed to anthropogenic Pb pollution over Poland. Coal and Pb-Zn ores, however, remained important sources of pollution in Eastern European countries during the last 50 years, as demonstrated by a high (206)Pb/(207)Pb ratio (1.153) relative to that of Western Europe (ca. 1.10). The Pb data for the last century were also in good agreement with modelled Pb inventories over Poland and the Baltic region.

Development of Lead-210 Measurement in Peat Using Polonium Extraction. A Procedural Comparison

Development of Lead-210 Measurement in Peat Using Polonium Extraction. A Procedural Comparison Two chemical treatments for lead-210 measurement were compared on the sub-surface samples of a core from an ombrotrophic bog from East Belgium. The classical procedure involves a concentrated acid extraction of polonium. However, this treatment represents substantial health risks together with unknowns regarding both the degree of cleanliness and the Po extraction rate, and most importantly, is rather time consuming. We developed here an improved procedure involving an ashing step prior to acid extraction. This allows substantial improvements such as: 1/ the use of a relatively small amount of acid compared to the classical procedure and 2/ the substantial reduction of a total sample digestion time. Measurements of 210Pb concentrations were conducted by alpha spectrometry. Results show a good agreement of unsupported 210Pb activity obtained for both procedures, although some unknowns remain concerning the adsorption of 210Po on the plastic test tube, the volatilization of a small amount of ash, or the absorption of alpha particle at the alpha source surface. This however should not affect the 210Pb measurement as all the samples are spiked prior to ashing (i.e. the recoveries are fully monitored). Through this study, we are suggesting researchers to follow this new procedure in order to increase safety, cleanliness, better recovery and substantial time gain.

Carbon accumulation rates in two poor fens with different water regimes: Influence of anthropogenic impact and environmental change

Fens are underestimated carbon sinks. Knowledge about their role in the sequestration of CO2 in the past is limited. The research reported here focused on identifying long-term carbon accumulation rates (CARs) in a drained fen (Bagno Bruch) and a waterlogged fen (Bagno Mikołeska) in southern Poland. On the basis of 210Pb and AMS 14C dates and age–depth modeling, 7000- and 2000-year records of changes in bulk composition and carbon and sulfur content are presented and discussed. Strong human impact is detected, especially in Bagno Bruch. However, minor climatic signals linked to the ‘Little Ice Age’ and to the influence of wind-blown sands are also evident. The sand may have influenced the plant composition, peat accumulation rates (PARs), and CARs, in addition to the bulk composition at Bagno Mikołeska. The mean value of the CAR in the youngest peat layers spanning the last 200 years is generally lower in two cores from Bagno Bruch (c. 85 and 86 g/m2/yr) than in two cores from Bagno Mikołeska (c. 140 and 142 g/m2/yr). The fens are characterized by higher CARs compared with boreal peatlands. The reproducibility of the CAR values is the most promising result, suggesting the low mobility of 210Pb and the reliability of this method in assessing the chronology of fens.

Radiocarbon and lead-210 age-depth model and trace elements concentration in the Wolbrom fen (S Poland)

Abstract A one-meter long peat core was taken from the peatland in Wolbrom (Silesian-Cracovian Upland, southern Poland). The analysis of the botanical composition showed that Wolbrom is a fen. Vegetation species such as Carex rostrata and Phragmites australis have been found. An age-depth model was constructed using 12 conventional radiocarbon dates and 13 lead-210 dates from the upper part of the deposit. In this work, the results of radiocarbon dating are presented. According to the model, we can estimate the age of the fen. The oldest part comes from a depth of 1.05 meter and its conventional age is 5940 ± 95 BP (modelled date 5000–4790 BC, 68.2% probability interval). The accumulation rate varies between approximately 0.53 mm·yr-1 and 6.48 mm·yr− 1. The core has been also tested for the presence of trace elements (Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) using ICP-OES. There are considerable variations in the concentrations of the tested metals – in many cases the concentration starts to rise at about 40 cm and may be connected with the human activity. This depth corresponds to the modelled age intervals 355–300 BC (17.4%) and 205–45 BC (50.7%).