Mobility of selected trace elements bound in brown coal of the Most basin

Cílem studia bylo posoudit extrahovatelnost vybraných kovů obsažených ve vzorcích hnědého uhlí při odlišném pH. Na základě těchto údajů pak stanovit prvky, u kterých je nezbytné hodnotit spíše jejich formu výskytu než absolutní koncentraci.  Některé prvky vázané v uhlí, jsou potenciálně lehce mobilizovatelné, a představují riziko pro okolní ekosystém. Bylo studováno celkem 10 vzorků uhlí z hlavní sloje mostecké pánve pomocí sekvenční extrakční procedury. Podmínky extrakcí byly nastaveny tak, aby reprezentovaly reálné situace. Pro nejslaběji vázané, a tedy lehce mobilizovatelné prvky byla použita extrakce deionizovanou vodou, množství slabě adsorbovaných iontů na povrchu pevné matrice bylo extrahováno pomocí 1M roztoku octanu amonného při pH = 7. Pro frakci vázanou na uhličitany příp. extrahovatelnou za mírně kyselých podmínek bylo použito téhož činidla při pH = 5. U poloviny hodnocených vzorků se největší množství arsenu  extrahovalo v uhličitanové frakci, u druhé poloviny bylo nejvíce arsenu uvolněno již při extrakci deionizovanou vodou. Pozitivní korelace byla zjištěna mezi celkovým množstvím As a Ni. Při korelování dat z jednotlivých extraktů se ovšem vztah nepotvrdil. Množství uvolněného niklu ve všech extrakčních krocích bylo velmi nízké. Významné množství vanadu a chromu bylo extrahováno již za použití deionizované vody u poloviny vzorků. Velmi blízké chování chromu a vanadu potvrzuje i pozitivní korelace během všech kroků extrakce.Some of the trace elements bound in coal are potentially easily mobilizable and can represent a risk for an ecosystem. The aim of the study was to evaluate the extractability of selected metals from brown coal samples under surface conditions. Totally, 10 coal samples from the Main seam of Most Basin were studied using a sequential extraction procedure. Extraction conditions were set to represent real conditions on a dump. Extraction with deionized water was used for the most weakly bound and thus easily mobilizable elements, the amount of weakly adsorbed ions on the surface of the solid matrix was extracted with 1M ammonium acetate solution at pH = 7. For the carbonate-bound fraction, respectively the fraction extractable under mildly acidic conditions, the same reagent at pH = 5 was used. Highest extractable contents in case of arsenic were found in deionized water for samples 03–07, other samples exhibited the highest recovery with weakly acidic reagent (pH = 5) with concentration 1 mol/l. Nickel concentrations in the extracts were mostly low (hundredths to tenths μg/g). Exceptions are water extractable contents (single units of μg/g) in samples 01, 08 and 09. A positive correlation (r = 0.69) was found between the total content of As and Ni, however, the contents of As and Ni do not mutually correlate in each type of extract. Significant contents of vanadium (up to 0.844 μg/g) and chromium (up to 0.28 μg/g) were already extracted using deionized water. Very close behavior of chromium and vanadium was confi rmed by positive correlation in mobile water extractable (r = 0.95) and carbonate fraction (r = 0.85)

Macro- and microelements in soil profile of the moss-covered area in James Ross Island, Antarctica

The study of Antarctic ecosystem provides a valuable insight into the nature development on the Earth. Biocenosis formation and colonization of land by organisms are noticeable especially in newly-deglaciated areas. In this research, soil profile development in the coastal zone of James Ross Island was investigated. The main objective was the characterisation of soil horizons. The contents of As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Se and Zn were measured using ICP-MS technique. Soil parameters like organic carbon content, pH and content ofsub-63 μm fraction were also determined. Based on the results obtained, the mineral-depleted and mineral‑enriched layers in the soil profile were distinguished. With increasing depth, the shallow soil profile consisted mainly of weathered regolith. Apparently, the basic processes which are prerequisite for the development of soil ecosystem in the studied area were confirmed

Levels and risks of antineoplastic drugs in households of oncology patients, hospices and retirement homes

Background Contamination of the indoor environment by antineoplastic drugs (ADs) is known to pose health risks to the exposed staff in hospitals or pharmacies. ADs may also contaminate households of the patients receiving chemotherapy, but the exposure levels and potential risks to family members have not been studied. The objective was to provide an in-depth research of surface contamination by ADs inside homes focusing on the households of oncology patients, hospices, and retirement houses. Methods The study was carried out in 17 patient households, 2 hospices, and 3 retirement homes. Surfaces were sampled using a standardized approach and the wipe samples were analyzed by UPLC-MS for 11 organic ADs and by ICP-MS/MS for total Pt as a marker of Pt-based ADs. Results The main study included repeated samplings of surfaces (floors, desktops) in households of 17 ambulant oncology patients receiving different chemotherapies with cyclophosphamide (CP), platinum-based drugs (Pt), doxorubicin (DOX), 5-fluorouracil (FU) and others. Patients treated with chemotherapy were found to serve as a source of contamination for their households, representing thus a risk to sensitive family members such as children or elderly people. Carcinogenic CP was commonly found at relatively high concentrations, especially during the first 6 days after the chemotherapy (maximum 511 pg/cm(2)). Sweat seems to be a major medium for the spread of the contamination, and high and long-time persisting CP levels (traces still found after 6 months post-chemotherapy) were found on various desktops including kitchen dining tables. The pilot studies in hospices and retirement homes indicated rather lower exposure risks of the personnel but pointed to potential long-lasting contamination by Pt or some other persistent ADs such as ifosfamide (IF). Conclusions This is one of the first studies investigating the contamination by ADs in indoor environments outside of hospitals or pharmacies. Peak concentrations of the carcinogenic CP in households were comparable to those observed in hospitals, but the temporal exposures are likely to cause lower risks to family members and caregivers compared to the long-time occupationally exposed health care personnel. The information guidance flier with practical recommendations was prepared improving thus information as well as prevention of eventual risks for family members

Nitrated monoaromatic hydrocarbons (nitrophenols, nitrocatechols, nitrosalicylic acids) in ambient air: levels, mass size distributions and inhalation bioaccessibility

Nitrated monoaromatic hydrocarbons (NMAHs) are ubiquitous in the environment and an important part of atmospheric humic-like substances (HULIS) and brown carbon. They are ecotoxic and with underresearched toxic potential for humans. NMAHs were determined in size-segregated ambient particulate matter collected at two urban sites in central Europe, Ostrava and Kladno, Czech Republic. The average sums of 12 NMAHs (Σ12NMAH) measured in winter PM10 samples from Ostrava and Kladno were 102 and 93 ng m−3, respectively, and 8.8 ng m−3 in summer PM10 samples from Ostrava. The concentrations in winter corresponded to 6.3–7.3% and 2.6–3.1% of HULIS-C and water-soluble organic carbon (WSOC), respectively. Nitrocatechols represented 67–93%, 61–73% and 28–96% of NMAHs in PM10 samples collected in winter and summer at Ostrava and in winter at Kladno, respectively. The mass size distribution of the targeted substance classes peaked in the submicrometre size fractions (PM1), often in the PM0.5 size fraction especially in summer. The bioaccessible fraction of NMAHs was determined by leaching PM3 samples in two simulated lung fluids, Gamble’s solution and artificial lysosomal fluid (ALF). More than half of NMAH mass is found bioaccessible, almost complete for nitrosalicylic acids. The bioaccessible fraction was generally higher when using ALF (mimics the chemical environment created by macrophage activity, pH 4.5) than Gamble’s solution (pH 7.4). Bioaccessibility may be negligible for lipophilic substances (i.e. log KOW > 4.5)

Proposals of guidance values for surface contamination by antineoplastic drugs based on long term monitoring in Czech and Slovak hospitals and pharmacies

IntroductionThe exposures to hazardous antineoplastic drugs (AD) represent serious risks for health care personnel but the exposure limits are not commonly established because of the no-threshold effects (genotoxic action, carcinogenicity) of many ADs. In this study, we discussed and derived practically applicable technical guidance values (TGV) suitable for management of AD risks.MethodsThe long-term monitoring of surface contamination by eight ADs was performed in pharmacies and hospitals in the Czech Republic and Slovak Republic in 2008–2021; in total 2,223 unique samples were collected repeatedly in 48 facilities. AD contamination was studied by LC-MS/MS for cyclophosphamide, ifosfamide, methotrexate, irinotecan, paclitaxel, 5-fluorouracil and gemcitabine and by ICP-MS for total Pt as a marker of platinum-based ADs.ResultsThe study highlighted importance of exposure biomarkers like 5-fluorouracil and especially carcinogenic and persistent cyclophosphamide, which should be by default included in monitoring along with other ADs. Highly contaminated spots like interiors of laminar biological safety cabinets represent a specific issue, where monitoring of contamination does not bring much added value, and prevention of staff and separated cleaning procedures should be priority. Rooms and surfaces in health care facilities that should be virtually free of ADs (e.g., offices, kitchenettes, daily rooms) were contaminated with lower frequency and concentrations but any contamination in these areas should be carefully examined.Discussion and conclusionsFor all other working places, i.e., majority of areas in pharmacies and hospitals, where ADs are being prepared, packaged, stored, transported, or administered to patients, the study proposes a generic TGV of 100 pg/cm2. The analysis of long-term monitoring data of multiple ADs showed that the exceedance of one TGV can serve as an indicator and trigger for improvement of working practices contributing thus to minimizing of unintended exposures and creating a safe work environment

Raman Microspectroscopic Analysis of Selenium Bioaccumulation by Green Alga Chlorella vulgaris

Selenium (Se) is an element with many commercial applications as well as an essential micronutrient. Dietary Se has antioxidant properties and it is known to play a role in cancer prevention. However, the general population often suffers from Se deficiency. Green algae, such as Chlorella vulgaris, cultivated in Se-enriched environment may be used as a food supplement to provide adequate levels of Se. We used Raman microspectroscopy (RS) for fast, reliable, and non-destructive measurement of Se concentration in living algal cells. We employed inductively coupled plasma-mass spectrometry as a reference method to RS and we found a substantial correlation between the Raman signal intensity at 252 cm(-1) and total Se concentration in the studied cells. We used RS to assess the uptake of Se by living and inactivated algae and demonstrated the necessity of active cellular transport for Se accumulation. Additionally, we observed the intracellular Se being transformed into an insoluble elemental form, which we further supported by the energy-dispersive X-ray spectroscopy imaging

Oxygenated and Nitrated Polycyclic Aromatic Hydrocarbons in Ambient Air-Levels, Phase Partitioning, Mass Size Distributions, and Inhalation Bioaccessibility

Among the nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs and OPAHs) are some of the most hazardous substances to public health, mainly because of their carcinogenicity and oxidative potential. Despite these concerns, the concentrations and fate of NPAHs and OPAHs in the atmospheric environment are largely unknown. Ambient air concentrations of 18 NPAHs, 5 quinones, and 5 other OPAHs were determined at two urban and one regional background sites in central Europe. At one of the urban sites, the total (gas and particulate) concentrations of Sigma(10)OPAHs were 10.0 +/- 9.2 ng/m(3) in winter and 3.5 +/- 1.6 ng/m(3) in summer. The gradient to the regional background site exceeded 1 order of magnitude. Sigma(18)NPAH concentrations were typically 1 order of magnitude lower than OPAHs. Among OPAHs, 9-fluorenone and (9,10)-anthraquinone were the most abundant species, accompanied by benzanthrone in winter. (9,10)-Anthraquinone represented two-thirds of quinones. We found that a large fraction of the target substance particulate mass was carried by submicrometer particles. The derived inhalation bioaccessibility in the PM10 size fraction is found to be approximate to 5% of the total ambient concentration of OPAHs and up to approximate to 2% for NPAHs. For 9-fluorenone and (9,10)-anthraquinone, up to 86 and 18%, respectively, were found at the rural site. Our results indicate that water solubility could function as a limiting factor for bioaccessibility of inhaled particulate NPAHs and OPAHs, without considerable effect of surfactant lipids and proteins in the lung lining fluid

Introduction of Direct Popular Presidential Election: Impact on Political System:Study 1.201

Práce přináší analýzu ústavněprávního postavení prezidenta v České republice a popisuje faktický výkon funkce prezidenta Václavem Havlem a Václavem Klausem, především pokud jde o snahu rozšiřovat pravomoci prezidenta nad ústavněprávní rámec. Součástí práce jsou i dvě případové studie popisující vývoj ve Finsku a na Slovensku po zavedení přímé volby prezidenta a dopad této změny na politický systém