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The city of Krakow located in southern Poland ranks among the most polluted urban agglomerations in Europe. There are persisting controversies with respect to impact of different pollution sources operating in Krakow agglomeration on air quality within the city. The presented pilot study was aimed at exploring the possibilities offered by elemental and carbon isotope composition of total suspended particulate matter (TSPM) for better characterization of its sources in Krakow atmosphere. The analyses of carbon isotope composition of total carbon in the investigated TSPM samples were supplemented by parallel analyses of radiocarbon content in atmospheric carbon dioxide (CO2). This study revealed large seasonal variability of carbon isotope composition in the analysed TSPM samples. This large variability reflects seasonally varying contribution of different sources of fossil and modern carbon to the TSPM pool. The elemental composition of TSPM also reveals distinct seasonal variability of the analysed elements, reflecting varying mixture of natural and anthropogenic sources of those elements. A linear relationship between the fossil carbon load in the TSPM samples and the fossil carbon load in the atmospheric CO2 was found, pointing to the presence of additional source of anthropogenic carbonaceous particles not associated with burning of fossil fuels. Wearing of tyres and asphalt pavement is most probably the main source of such particles.

Anthropogenic emissions of carbon dioxide (CO2) and methane (CH4) in the atmosphere constitute an important component of the related carbon budget. The main source of anthropogenic CO2 is burning of fossil fuels, especially in densely populated areas. Similar emissions of CH4 are associated with the agricultural sector, coal mining, and other human activities, such as waste management and storage and natural gas networks supplying methane to large urban, industrial centers. We discuss several methods aimed at characterizing and quantifying atmospheric loads and fluxes of CO2 and CH4 in Krakow, the second largest city in Poland. The methods are based on atmospheric observations of mixing ratios as well as isotopic composition of the investigated gases. Atmospheric mixing ratios of CO2 and CH4 were measured using gas chromatography (GC) and cavity ring-down spectroscopy (CRDS). The isotopic composition of CO2 and CH4 was analyzed using isotope ratio mass spectrometry (IRMS), accelerator mass spectrometry (AMS), and CRDS techniques. These data, combined with auxiliary information characterizing the intensity of vertical mixing in the lower atmosphere (height of the nocturnal boundary layer [NBL] and atmospheric 222Rn concentration), were further used to quantify emission rates of CO2 and CH4 in the urban atmosphere of Krakow. These methods provide an efficient way of quantifying surface emissions of major greenhouse gases originating from distributed sources, thus complementing the widely used bottom-up methodology based on emission statistics.

The development of high quality nuclear data, radiation detectors and instrumentation techniques for fusion technology applications in Europe is supported by Fusion for Energy (F4E) and conducted in a joint and collaborative effort by several European research associations (ENEA, KIT, JSI, NPI, AGH, and CCFE) joined to form the "Consortium on Nuclear Data Studies/Experiments in Support of TBM Activities". This paper presents the neutronics activities carried out by the Consortium. A selection of available results are presented. Among then a benchmark experiment on a pure copper block to study the Cu cross sections at neutron energies relevant to fusion, the fabrication of prototype neutron detectors able to withstand harsh environment and temperature >200 °C (artificial diamond and self-powered detectors) developed for operating in ITER-TBM as well as measurement of relevant activation and integral gas production cross-sections. The latter measured at neutron energies relevant to IFMIF (>14 MeV) and the development of innovative experimental techniques for tritium measurement in TBM. © 2015 Elsevier B.V. All rights reserved.

Liquid scintillation (LS) technique applied to direct measurement of tritium activity produced in LiPb eutectic in Frascati HCLL TBM mock-up neutronic experiment has been tested so far in the case of LS measurement after long period since irradiation. LiPb samples irradiated in neutron filed show, except of tritium, meaningful activity of other radioisotopes (parasitic). Parasitic activity, mainly from isotopes of lead ( 209 Pb, 204m Pb, 203 Pb) calculated with the use of FISPACT, exceeds ca 5 times tritium activity 1.4 h after irradiation. We propose to remove disturbing radioisotopes in a chemical way to avoid long “cooling” of the irradiated samples before tritium measurement. Samples (1 g of LiPb) irradiated in reactor fast neutron flux were diluted and metallic cations removed by chemical precipitation. For this purpose we used: potassium iodide (KJ), strontium chloride (SrCl 2 ), APDC (C 5 H 8 NS 2 ·NH 4 ), NaDDTC (C 5 H 10 NNaS 2 ·3H 2 O), and PAN (C 15 H 11 N 3 O). Precipitation procedure in each case lasted ca 5–25 min, and the following filtration next 10–20 min. In each filtrate (ca 120 ml) we measured Pb concentration in total reflection X-ray fluorescence (TXRF) analyzer and parasitic activity (left after 21-day “cooling”) applying HPGe gamma spectrometer. Pb cations precipitated by SrCl 2 and than by PAN lowered activity of Pb isotopes to less than 1% of the initial tritium activity. Another combination of reagents: NaDDTC followed by SrCl 2 in a single and double step filtration reduced Pb concentration 10 2 and 10 4 times, respectively. Reduction of this order allows tritium radiometric measurement ca 3 h after irradiation with acceptable accuracy. This time can be shortened by applying correction for decay of known parasitic activity. Input of 76 As and other less abundant radioisotopes can be eliminated using high purity LiPb. Tritium activity of the filtrates measured in LS spectrometer showed no dependence upon used reagent being, within measurement error, the same as for analyzed LiPb samples.

Validation of the calculated Tritium Production Rate (TPR) in the Test Blanket Modules (TBMs) needs relatively simple measurement procedure. Measurement system in TBM based on Tritium determination directly in LiPb and/or in Li compound(s) with application of the Liquid Scintillator Counting (LSC) is proposed. Expected high temperature in TBM while ITER operation in sample not less than 150 °C when cooled irradiated material, and 300–400 °C without cooling, impose constraints on the possible methods and technical design. Preliminary results performed on irradiated LiPb eutectic pellets housed at controlled conditions of elevated temperature showed remarkable loss of Tritium. Observed escape of Tritium ranged from ca. 91% (temp.: 300 °C, t = 60 min) to ca. 52% (temp.: 370–390 °C, t = 10 min) being in fair agreement with calculated values by use of dedicated code (rCADiff). Basic limitation of direct radiometric measurement of Tritium activity in LiPb is parasitic activity induced in Pb, predominantly coming from 203 Pb and also from impurities present in Pb. Demand of obtaining information on TPR in relatively short time points to other lithium compounds used as monitors which after irradiation, followed by an easy preparation procedure, can be measured using simple version of LSC. Most promising monitors seem to be Li 2 O and LiF. Two different possible versions of the proposed systems were considered: (1) LSC measurement starts after long period of time since irradiation (not less than 20 days); (2) LSC measurement starts shortly after irradiation (an hour or less to several hours).

Southern Poland is home to numerous large mining and energy industry facilities, which consume relatively great amounts of fossil fuels. Temporal and spatial distribution of CO2 emissions to the atmosphere were estimated on the basis of 13C and 14C isotope measurements in atmospheric CO2 and in α-cellulose from pine tree rings. The Suess effect was evaluated in the atmospheric CO2 from the High Tatra Mountains (Kasprowy Wierch) and the urban area (Kraków), as well as in tree rings from Niepołomice Forest near Kraków. Two different models were used to estimate the emission component recorded in tree ring δ13C on the background of climatic changes.

We report and compare the results of long-term observations (1998–2006) of monthly mean soil CO2 fluxes and their carbon isotope composition, carried out at 3 sites with contrasting characteristics: 1) a grassland site located in the urban area of Krakow, southern Poland, which was exposed to anthropogenic impact for more than a century; 2) a mixed forest site; and 3) cultivated agricultural field site. A closed-chamber, dynamic sampling system was used to collect monthly cumulative samples of soil-respired CO2. The CO2 collected at the mixed forest site was enriched in 14C with respect to European free-atmosphere continental 14CO2 background (high-altitude station Jungfraujoch in Swiss Alps) by approximately 40%, while the urban site revealed 14C depletion by ∼30% against the same reference. The Δ14C values observed at the agricultural site were lying in between, clustering along the regional reference atmospheric Δ14CO2 trend curve. The Δ14C values of soil-respired CO2 at the urban site turned out to be indistinguishable from the Δ14CO2 values in the local atmosphere. For the estimation of mean turnover time of soil carbon for each of the monitored sites, we used a multicompartment model (MCM) accounting for input of carbon to the soil profile via deposition of fresh organic matter, as well as 3 different sources of CO2 in the soil profile: 1) root respiration; 2) “fast”; and 3) “slow” pools of soil carbon. The estimated mean turnover time of carbon in the “fast” carbon pool was ∼14 yr for both urban grassland and mixed forest sites, and ∼22 yr for the cultivated agricultural field. From the observed differences in Δ14C values of the measured fluxes of soil-respired CO2, we conclude that 14C content of the biogenic component in the local atmospheric CO2 is site-specific and may differ significantly from the regional atmospheric background Δ14CO2 value. Therefore, the assumption widely used in 14C-based assessments of the fossil-fuel contribution local atmospheric CO2 load, stating that 14C concentration in the biogenic CO2 component is equal to that of regional atmospheric reference value, needs to be carefully evaluated on a case-by-case basis.

We present the results of a comprehensive study aimed at tracing the evolution of carbon isotopic composition of the TDIC (total dissolved inorganic carbon) reservoir from the unsaturated zone down to the discharge area, in a sandy aquifer near Kraków, southern Poland. A multilevel well penetrating the unsaturated zone in the study area was equipped with horizontally mounted lysimeters with ceramic suction cups to collect samples of pore water and metal probes to collect soil air. Strong seasonal fluctuations were observed of soil pCO2 extending down to the water table, coupled with distinct, well-defined depth profiles of δ13CTDIC reaching approximately −10′ at 8 m depth and almost constant radiocarbon content in the TDIC pool, comparable to 14CO2 levels in the local atmosphere. Simple models (closed/open system) do not account for the observed depth variations of carbon isotopic composition of the TDIC pool. This suggests that the TDIC reservoir of pore waters is evolving under conditions gradually changing from an open towards a closed system. In order to explain 13C and 14C content of dissolved carbonates in groundwater in the recharge area of the studied aquifer, additional sources of carbon in the system are considered, such as organic matter decomposition accompanied by reduction of dissolved nitrates and sulfates. The piston-flow l4C ages of groundwater in the confined part of the studied system were calculated using 2 approaches: 1) the correction model proposed by Fontes and Garnier (1979) was used to calculate groundwater ages, utilizing the chemical and carbon isotopic data available for the sampled wells; and 2) inverse geochemical modeling was performed for selected pairs of wells using NETHPATH code. The calculated 14C ages of groundwater range from approximately 0.6 to 37.5 ka BP. Although both methods appeared to be in a broad agreement, NETHPATH calculations revealed that isotopic exchange processes between TDIC pool and solid carbonates present in relatively small amounts in the aquifer matrix play an important role in controlling the 13C and 14C signatures of the dissolved carbonate species in groundwater and should be taken into account when 14C ages are calculated.

New attempts arc presented to determine the age of large Pleistocene mammals excavated at Starunia, ∼130 km southeast of Lviv, Ukraine. This remarkable discovery made at the beginning of the 20th century included a complete carcass of woolly rhinoceros (No. 2), fragments of 3 woolly rhinoceroses (Nos. 1, 3, and 4) and remnants of numerous specimens of other fossil fauna and flora. Although attempts to date paleontological findings from Starunia site go back to the early 1970s, the results obtained before 2006 arc somewhat misleading, mostly due to unresolved contamination problems. Comprehensive cleaning of the samples adopted in the framework of this study was aimed at removal of 2 potential sources of contamination: (i) radiocarbon-free hydrocarbons abundant at the burial site; and (ii) allochthonous organic materials containing contemporary carbon that were used in the past during preservation of the dated specimens. Two types of samples have been analyzed for their 14C content in the framework of the present study: (i) fragments of bones and teeth collected from specimens stored or exposed in the Natural History museums in Lviv and Kraków; and (ii) samples of terrestrial macrofossils retrieved from sediment cores obtained during the 2007–2008 field campaigns in the Starunia area. 14C analyses of collagen were supplemented by measurements of its elemental C/N ratio and 13C/12C and 15N/14N isotope ratios. Three 14C dates obtained for rhinoceros No. 2 span the age range from 35.3 to 40.0 ka BP, in agreement with the minimum age estimated from macrofossils. The mean value of 37.7 ± 1.7 ka BP falls in the range of ages reported for big Pleistocene mammals from other locations in Europe. The bones of rhinoceros No. 3, which were found in close vicinity to those of rhinoceros No. 2, reveal a 14C age of 36.7 ± 0.6 ka BP. The δ15N and δ13C values obtained for collagen extracted from bones and teeth belonging to rhinoceroses Nos. 1, 2, and 3 are in a broad agreement with analogous literature data for large Pleistocene mammals found in other sites in Europe, North America, and Siberia.

Two novel methods of tritium production rate (TPR) measurements applied in HCLL TBM mock-up neutronic experiment are described and discussed. In the first method LiF TLD detectors used for gamma radiation dose measurements are applied as detectors of −β decay of tritium (T) produced by neutrons. TL signal expressed as mGy/h is proportional to energy accumulated in self-irradiation process (SI). However, the TL signal is proportional to tritium activity generated in detector material, recalculation to Bq/mg requires calibration by independent measurement of T activity in the TLD. In our experiments determination of this activity was performed by LSC technique. Good correlation between the 3H activity and TLD signal was observed. The second presented method is based on direct measurement of T in LiPb material with the use of LSC spectrometer. Dissolution of LiPb in nitric acid, and than composing aliquot containing well known mass of irradiated LiPb mixed than with scintillation cocktail, is measured in LS spectrometer providing signal proportional to the T activity. It was proved by series of experiments that procedure performed at controlled conditions ensures no loss of tritium while preparation. Optimization measurement conditions with respect of type of the scintillator used and composition of aliquot/scintillator mixture provide counting efficiency above 22%. Sample material for testing the both techniques was irradiated by neutron flux either at nuclear research reactor “Maria”, Świerk, Poland or at the Frascati Neutron Generator Laboratory in HCLL TBM neutronic experiment. Li2CO3 pellets used as reference were irradiated in the same experiment with TLDs, and samples of LiPb-eutectic and then analysed by modified Dierckx method, a well established technique. Measurement results obtained applying the both techniques described above as well as the control Li2CO3 pellets were in very good consistency. Direct measurements of T produced in LiPb at different depth in HCLL TBM mockup agrees well with MCNP simulation results. Parameters of the simulation provide additionally information on 6Li abundance and Li content in the LiPb mixture. Spread of the T activity observed at the same depth for different samples correspond with inhomogeneity of the eutectic composition investigated and reported. Direct measurement of T activity seems to be the very promising and relatively simple method of validation of neutronic codes and nuclear data capabilities for calculation TPR in fusion relevant materials provided parameters of the irradiated material are well known.

Time series are presented of radiocarbon and 13C contents in atmospheric carbon dioxide over eastern Europe (southern Poland), covering the periods 1983–1994 and 2000–2004. The carbon isotope composition was measured in biweekly composite samples of atmospheric CO2, collected about 20 m above the local ground level. The data for 2 observational sites are presented: i) city of Kraków (50°04′N, 19°55′E; 220 m asl; for 1983–1994 and 2000–2004); and ii) Kasprowy Wierch, Tatra Mountains (49°14′N, 19°56′E; 1989 m asl; for 2000–2004). The latter site is considered a regional reference station, relatively free of anthropogenic influences. During the period 1983–1994, observations in the Kraków area revealed a gradual decrease of 14C content with a broad minimum around 1991 and a small increase by about 10% in the subsequent years. δ13C also changes with time, showing a decreasing trend from approximately −9.6% in 1983, with a slope of −0.02%/yr. The observed trends for both isotopes coincide well with a substantial reduction of coal consumption in Poland and partial replacement of coal by natural gas, especially in urban regions. After 2000, the δ13C slightly increases, reaching a mean value of −10% in 2004, while Δ14C is below the reference level by ∼3.5%. Observations at Kasprowy Wierch (regional reference station) also reflect a diminishing input of fossil carbon into the regional atmosphere. The fossil component in atmospheric CO2, calculated with the aid of 14C data available for the 2 study periods, shows a reduction of anthropogenic input by a factor of 2, which is confirmed by annual statistics of coal consumption.

A comprehensive study of a sandy aquifer of deltaic origin in southern Poland included water chemistry, isotopes, dissolved trace gases and transport modelling. Tritium, sulphur hexafluoride (SF6) and freons (F-11, F-12 and F-113) showed the presence of modern waters in the recharge areas and shallow confined parts of the aquifer. The presence of older Holocene waters farther from the recharge areas was indicated by lack of 3H, SF6 contents ≤0·02 fmol l−1 and relatively low 14C values. The discharge from the system is by upward seepage in the valley of a major river. Pre-Holocene waters of a cooler climate, identified on the basis of δ18O, δ2H, 14C, Ne and Ar data, were found in some distant wells. Concentrations of N2, Ne and Ar determined by gas chromatography were used for calculating the noble gas temperatures, air excess needed for correction of SF6, and nitrogen content released by denitrification process. The time series of 3H content available for some wells supplied quantitative information on age distributions and the total mean ages of flow through the unsaturated and saturated zones. The derived 3H age distributions turned out to be very wide, with mean values in the range of about 30 to 160 years. For each well with determined 3H age, the SF6 data showed either a lower age range or the possibility of a lower age as expected due to shorter travel times of SF6 through the unsaturated zone, which most probably also resulted in different types of age distributions of these tracers. Freons appeared to be of little use for individual age determinations. A quantitative estimation of two-component mixing from SF63H relations is not possible unless the travel time of 3H through the unsaturated zone is comparable to that of SF6. The ratio of integrals of the response function over the age range with tracer and the whole response function yields the ratio of water with tracer to total flow of water. That ratio is a tracer-dependent function of time. Transport modelling of SF6 tracer done with MT3D code yielded initially large discrepancies between calculated and measured tracer concentrations. Some discrepancies remained even after calibration of the transport model with SF6. Simulation of tritium contents with a calibrated transport model yielded reasonable agreement with measured contents in some wells and indicated a need for further investigations, particularly in the eastern part of the aquifer. The existence of distinct hydrochemical zones is consistent with the tracer data; young waters with measurable 3H and SF6 contents are aerobic and of HCO3Ca or HCO3SO4Ca types. Slightly elevated Na and Cl contents, as well as the highest concentrations of SO4 and NO3 within this zone are due to anthropogenic influences. Anaerobic conditions prevail in the far field, under the confining cover, where pre-bomb era Holocene waters dominate. In that zone, dissolved oxygen, NO3 and U contents are reduced, and Fe, Mn and NH4 contents increase. In the third zone, early Holocene and glacial waters occur. They are of HCO3CaNa or HCO3Na types, with TDS values higher than 1 g l−1 and Na content higher than 200 mg l−1, due to either small admixtures of ascending or diffusing older water or freshening of marine sediments, a process that is probably occurring till the present time. Copyright © 2005 John Wiley & Sons, Ltd.

New results of radiocarbon concentration in tree rings from the Kraków region covering a growth period of 20 yr have been analyzed, and the relationship between them and 14C concentrations in the atmospheric CO2 are described. This enabled assessment of the uptake period for pine trees at the regional climatic conditions. Both sets of data show lower 14C concentrations than reported for “clean air” at the reference station, indicating a remarkable input of “dead” CO2 of fossil fuel origin. Using data of carbon dioxide and 14C concentrations from Schauinsland, summer values of the fossil component (Cf) in carbon dioxide were calculated for the Kraków area. Fitting exponential and linear functions to experimental data, the exchange time was calculated, and expected future 14C concentration in the atmosphere was estimated.

Regular observations of atmospheric mixing-ratios of carbon dioxide and methane in the urban atmosphere, combined with analyses of their carbon-isotope composition (δ13C, δ14C), provide a powerful tool for assessing both the source strength and source partitioning of those gases, as well as their changes with respect to time. Intense surface fluxes of CO2 and CH4, associated with anthropogenic activities result in elevated levels of these gases in the local atmosphere as well as in modifications of their carbon-isotope compositions. Regular measurements of concentration and carbon-isotope composition of atmospheric CO2, carried out in Krakow over the past two decades, were extended to the period 1995–2000 and also to atmospheric mixing-ratios of CH4 and its carbon-isotope composition. Radiocarbon concentrations (δ14C) in atmospheric CO2 recorded at Krakow are systematically lower than the regional background levels. This effect stems from the addition of 14C-free CO2 into the local atmosphere, originating from the burning of fossil fuels. The fossil-fuel component in the local budget of atmospheric carbon calculated using a three-component mixing model decreased from ca. 27.5 ppm in 1989 to ca. 10 ppm in 1994. The seasonal fluctuations of this component (winter–summer) are of similar magnitude. A gradually decreasing difference between the 14CO2 content in the local atmosphere and the regional background observed after 1991 is attributed to the reduced consumption of 14C-free fuels, mostly coal, in southern Poland and the Krakow municipal area. The linear regression of δ13C values of methane plotted versus reciprocal concentration, performed for the data available for Krakow sampling site, yields the average δ13C signature of the local source of methane as being equal to −54.2‰. This value agrees very well with the measured isotope signature of natural gas being used in Krakow (−54.4±0.6‰) and points to leakages in the distribution network of this gas as the main anthropogenic source of CH4 in the local atmosphere.

A European nuclear-fusion technology program is currently, except of other acivities, on the stage of validating the capability of neutronic codes and nuclear data for use in the ITER project. This requires a technique for reliable measurements of tritium produced by a neutron flux and these estimates must have a qualified uncertainty. The application of LiF TL detectors, calibrated by the direct measurement of tritium activity using the Liquid Scintillation Counting (LSC) technique, is a new approach to the assessment of the tritium production rate in fusion related benchmark experiments. Lithium Fluoride Thermoluminescent Detectors (TLD) are commonly used for measurements of thermal neutron dose using the 6 Li(n,α) 3 H reaction. The accumulation of radioactive tritium in the LiF detectors is usually considered as an undesired effect to the detectors, increasing intrinsic background after high-dose neutron exposure. The same effect may be exploited for the measurement of generated tritium activity. A TL signal corresponding to the energy deposited in the − β decay of 3 H, expressed as mGy/h to be recalculated to Bq/mg, requires calibration by an independent measurement of 3 H activity. This calibration can be performed by applying e.g. LSC-technique. A good correlation was obtained in the tested range of tritium activity: 17–25 Bq/mg of LiF (0.080–0.118 mGy/h) with a slope of regression line: 1.75 × 10 −4 [mGy/h]/[Bq], r 2 = 0.94. The thermal treatment of the TLDs after irradiation (annealing: 400 °C, 1 h) leads to a loss of 37% of the initial tritium content. Prolonged storage of the irradiated TLDs at room temperature, pressure and humidity causes the escape of less than 5% of the accumulated tritium after 100 days. Thus LiF TLDs after calibration can be used as one of techniques for the assessment of tritium production in neutronic experiments.

A dedicated effort on nuclear data validation and nuclear instrumentation techniques for Test Blanket Modules (TBM) in ITER is conducted as an integral part of Fusion for Energy's (F4E) programme to ensure validated nuclear analysis capabilities for fusion technology applications. It is closely linked to nuclear data development activities, which are jointly coordinated and conducted by F4E and nuclear data consortia formed by European research institutions. The current experimental activities, an integral copper validation experiment and gas production experiments in EUROFER elements, as well as activities on the development and testing of candidate nuclear detectors for TBM in ITER and the related design integration assessment are presented in this paper. ﾩ 2014 Fusion for Energy.

The application of traditional gas or liquid scintillation counting (LSC) is necessary for assessing radionuclide activity in countries without operating accelerator mass spectrometry (AMS) facilities. A simple and relatively inexpensive system of mini gas counters for measurement of radiocarbon in archaeological and environmental samples has been set up recently in the Kraków laboratory (Department of Environmental Physics, University of Mining and Metallurgy). The system is composed of a gas purification and counter filling line, three identical 15-mL copper/quartz counters, active and passive shielding, and an electronic unit with data acquisition. One counter measures 22 mg of carbon as CO2 with efficiency >95% at a background reduced to 0.044 cpm by a NaJ(Tl) guard counter and lead shield. The detection limit (1 σ) for a two-week measurement of 48 mL of CO2 is 0.52 pMC. The corresponding counting error of a 100 pMC environmental sample is 1.3 pMC for 22 mgC (one counter) and 0.75 pMC for 66 mgC (three counters filled with the same sample).

Time series of δ14C, δ13C, and concentration of atmospheric CO2 covering the last 12 years are available at the Kraków sampling site (southern Poland) representing an urban area exposed to anthropogenic pollution of both local and regional origin. The samples represent continuous monitoring in biweekly intervals. Observations covering the time period 1983–1994 show a linear decrease of the 13C/12C ratio (δ13C = −9.6% in Jan. 1983) with a slope of −0.02% a−1. The decreasing tendency in the case of 14C (δ14C = 221% in January 1983) is weaker with a broad minimum in 1991 (δ14C = 124%) and subsequent gradual increase by ca. 10%, coinciding with a substantial reduction of coal consumption in Poland (26% reduction in 1991–1994 for heat and electricity production), partly compensated in agglomerations by increased gas consumption. The 12-year record of the CO2 concentration in Kraków points to a constant value fluctuating at a high level (average: 373 ppmv) reaching a maximum yearly average of 376 ppmv. These carbon isotope signatures were used for the separation of fossils from biogenic and “background” components, reflecting the strength of relevant sources. The monthly mean of the fossil component varies from ca. 10 ppmv in June to 27.5 ppmv in March while the yearly mean decreased ca. 16 ppmv since 1991.

THE various reservoirs of the global carbon cycle, with their very different residence times, are linked by a complex and evolving system of exchanges for which natural radiocarbon is the most robust tracer1. Any change in the sizes of these reservoirs, or the exchange rates between them, could perturb the 14C/12C ratio of each other reservoir, and the smallest of them—the atmosphere— would be the most sensitive. In particular, high-resolution reconstructions of past atmospheric 14C/12C ratios may provide important clues to the mechanisms of abrupt climate change. Annually laminated lake sediments potentially provide an optimal record in this respect, as they preserve information about both past atmospheric 14C levels and climate changes, providing absolutely dated material beyond the range of tree-ring chronologies and, unlike corals, directly monitor 14C concentrations in atmospheric CO2. Here we report the relationship between atmospheric 14C concentration and climate changes during the Younger Dryas and early Holocene periods, derived from analyses of the annually laminated sediments of Lake Gśoscia¸azz, in central Poland. We find that atmospheric 14C concentrations during the Younger Dryas were abnormally high, which we interpret as a reduced ventilation rate of the deep ocean, most probably as a result of a decrease in intensity of the North Atlantic Deep Water formation.

Regular measurements of atmospheric CO (2) mixing ratios and their carbon isotope composition ((13)C/(12)C and (14)C/(12)C ratios) performed between 2005 and 2009 at two sites of contrasting characteristics (Krakow and the remote mountain site Kasprowy Wierch) located in southern Poland were used to derive fossil fuel-related and biogenic contributions to the total CO (2) load measured at both sites. Carbon dioxide present in the atmosphere, not coming from fossil fuel and biogenic sources, was considered 'background' CO (2). In Krakow, the average contribution of fossil fuel CO (2) was approximately 3.4%. The biogenic component was of the same magnitude. Both components revealed a distinct seasonality, with the fossil fuel component reaching maximum values during winter months and the biogenic component shifted in phase by approximately 6 months. The partitioning of the local CO (2) budget for the Kasprowy Wierch site revealed large differences in the derived components: the fossil fuel component was approximately five times lower than that derived for Krakow, whereas the biogenic component was negative in summer, pointing to the importance of photosynthetic sink associated with extensive forests in the neighbourhood of the station. While the presented study has demonstrated the strength of combined measurements of CO (2) mixing ratios and their carbon isotope signature as efficient tools for elucidating the partitioning of local atmospheric CO (2) loads, it also showed the important role of the land cover and the presence of the soil in the footprint of the measurement location, which control the net biogenic surface CO (2) fluxes.

The isotopic composition of atmospheric CO2 and its concentration in the Krakow region has been measured since 1983. Air samples have been collected in bi-weekly intervals close to the center of Krakow. The six years records (1983–88) of these data reveal multi-annual linear trends and winter-summer oscillations. The calculated parameters of the individual regression lines (intercept and slope) for the measured Δ14C, δ13C and CO2 concentration, C, are: 173‰ (January 1983) and − 10.7‰ yr-1, − 9.58‰ (January 1983) and – 0.038‰ yr-1, 371 ppmv (January 1983) and 1.0 ppmv yr-1, respectively. The 14C activity in tree leaves collected in a mountain region, about 60 km from Krakow was also assessed. The parameters of the linear decrease of 14C activity in tree leaves are: 239‰ (January 1983) and 21‰ yr-1.DOI: 10.1034/j.1600-0889.1991.t01-4-00003.x

In this paper we present the high-resolution record of proxy climatic data in central Europe during the final stages of the last deglaciation, derived from the annually laminated sediments of Lake Gościaz (central Poland). The isotopic, palynological and other microfossil data confirm sudden changes of climate at the onset and termination of the Younger Dryas (completed within 150 and 70 years, respectively), in close agreement with the previous estimates derived from the polar ice cores and marine sediments. In the upper YD some amelioration of climate took place already about 600 years before the main YD/Preboreal transition. Counting of annual varves in the lake sediments allows a direct estimate of the duration of the Younger sDryas in central Europe; it lasted approximately 1640 years, substantially longer than suggested by previous estimates derived from laminated lake sediments and glacial varves, but agreeing with the radiocarbon calibration data obtained for Barbados corals. The calendar ages of the boundaries of the YD, 12,920 and 11,280 cal BP, are tentatively set.

Laminated sediments of Gościaż Lake can be used as an independent source of material for calibrating the radiocarbon time scale. The varve chronology is based on three long cores from the deepest part of the lake, with one additional core from the second deepest part. From pollen and Cladocera spectra and stable isotope and chemical content sequences, we have determined the Allerød(AL)/Younger Dryas(YD) and Younger Dryas/Preboreal(PB) boundaries in the three long cores with relatively good accuracy, and have tentatively defined the AL/YD boundary in the fourth core. The Younger Dryas period contains at least 1520 varves, with 980 varves in fragments well replicated in all four cores. The duration of the Younger Dryas as recorded in sediments of Gościaż Lake corresponds well to the duration derived from 230Th/234U and 14C dates on Barbados corals, but disagrees with estimates from Soppensee, Lake Holzmaar and Swedish varves. Two AMS dates of terrestrial macrofossils from the PB and YD periods seem to fit both the data obtained for Swiss lake sediments and Barbados corals.

The results of regular observations of atmospheric CO2 mixing ratios and its carbon isotope composition (?13C, ?14C), carried out at two continental sites located in central Europe are presented and discussed. The sites (Kasprowy Wierch, 49°14' N, 19°59' E, 1989 m a.s.l.; Krakow, 50°04' N, 19°55' E, 220 m a.s.l.), are located in two contrasting environments: (i) high-altitude mountaneous area, relatively free of anthropogenic influences, and (ii) typical urban environment with numerous local sources of carbon dioxide. Despite of relative proximity of those sites (ca. 100 km), substantial differences in both the recorded CO2 levels and their isotopic composition were detected. The CO2 mixing ratios measured in the urban atmosphere revealed quasi-permanent excess concentration of this gas when compared with near-by background atmosphere. The annual mean CO2 concentration recorded in Krakow in 2004 was almost 10% higher than that recorded at high-altitude mountain site (Kasprowy Wierch). Such effect is occuring probably in all urban centers. Carbon isotopic composition of atmospheric CO2 proved to be efficient tool for identification the surface CO2 fluxes into the atmosphere related to fossil fuel burning and their influence on the recorded levels of this gas in the local atmosphere. The available records of ?14C for Krakow and Kasprowy Wierch suggest gradual reduction of 14C-free CO2 fluxes into the urban atmosphere of Krakow in the past several years.

Among 92 patients with chronic gastritis we conducted a synchronous diagnosis of the Helicobacter pylori (H. pylori) infection using a culture and a serological test (IFP), in conjunction with breath and urine tests involving (14)C-urea (BTU-C14 and UTU-C14). The infection was confirmed by isolation in 71 persons (77.2%), the presence of specific IgG in the blood serum was found in 75 (81.5%). In comparison, the BTU-C14 indicated a group of 77 people (83.7%) as infected, and the UTU-C14 a group of 76 (82.6%). In order to determine the diagnostic value (sensitivity, specificity and efficiency) of the latter tests, the results were compared with those of the culture and of the serological tests. It was found that the BTU-C14 test used showed a 100% sensitivity, a 89.5% specificity and a 97.9% efficiency. The UTU-C14 test showed a 100.0% sensitivity, a 94.4% specificity and a 98.9% efficiency in the detection of the H. pylori infection.

The isotopic composition of atmospheric CO 2 and its concentration in the Krakow region has been measured since 1983. Air samples have been collected in bi-weekly intervals close to the center of Krakow. The six years records (1983–88) of these data reveal multi-annual linear trends and winter-summer oscillations. The calculated parameters of the individual regression lines (intercept and slope) for the measured Δ 14 C, δ 13 C and CO 2 concentration, C, are: 173‰ (January 1983) and − 10.7‰ yr -1 , − 9.58‰ (January 1983) and – 0.038‰ yr -1 , 371 ppmv (January 1983) and 1.0 ppmv yr -1 , respectively. The 14C activity in tree leaves collected in a mountain region, about 60 km from Krakow was also assessed. The parameters of the linear decrease of 14 C activity in tree leaves are: 239‰ (January 1983) and 21‰ yr -1 . DOI: 10.1034/j.1600-0889.1991.t01-4-00003.x

The Krakow Radiocarbon Laboratory has been measuring isotope composition of atmospheric CO2 and its natural concentration in the Kraków region for the last five years. We have been sampling on a continuous basis in two-week intervals at ca 20m above ground level, close to the center of Kraków. CO2 was sorbed while slow pumping atmospheric air through a molecular sieve. After recovery by heating, the CO2 was converted to benzene and 14C measured in a liquid scintillation spectrometer. In a small portion of CO2 δ13C was determined in a mass spectrometer. Concentration of CO2 was assessed by measurement of the volumes of the sorbed CO2 and the pumped air. A five-year record (1983–1987) reveals a multi-annual linear trend and winter-summer oscillations. Calculated parameters of the regression line (intercept and slope) for the measured δ14C, δ13C and concentration are: 222 (Jan 1983) and −15.5/yr, −9.57% (Jan 1983) and −0.042/yr, 336ppm (Jan 1983) and 1.4ppm/yr, respectively.

Results of the 14C measurements in atmospheric CO2 in the first half of 1986 are presented. CO2 samples were systematically collected in Krakow in two-week cycles and, after conversion to benzene, measured in a liquid scintillation spectrometer. 14C activity and 13C/12C ratio are reported as δ14C and δ13CPDB, respectively. For about three weeks after April 26, 1986 (the Chernobyl accident) an increase of ∼9% above the normal level for Krakow was observed. A rough estimate of the 14C release to the lower atmosphere during the accident gave a value 900 Ci, which is ∼1.8 × 10−5 of the total activity released to the atmosphere.

The Krakow Radiocarbon Laboratory is part of the Environmental Physics Department headed by T Florkowski and belongs to the Institute of Physics and Nuclear Techniques, The Academy of Mining and Metallurgy. A 3H and 14C laboratory was built primarily for the assessment of natural radioactivity in groundwater. In 1982, 14C preparation facilities were extended to include a combustion system for organic samples. The 14C measurement method is liquid scintillation counting on synthesized benzene in an LSC spectrometer TRI-CARB model 3320 (Packard International).