For over 50 years Lake Licheńskie (LLi), central Poland, has been involved in the cooling system of two power plants (PP). Owing to the discharge of cooling waters the lake was prone to considerable ...environmental changes which involved its thermal structure, mixing regime and water parameters. In this study we investigated how the man‐made transformations affected greenhouse gas emissions (GHG; CH4 and N2O) from the lake. The GHG emissions in Lake Licheńskie were monitored at the deepest site from December 2014 to November 2015 and between March 2022 and February 2023. The values obtained were compared to reference lakes encompassing 10 natural and undisturbed inland and coastal lakes in Poland. Our results revealed that LLi was a net source of CH4 and N2O to the atmosphere but the fluxes were low. The mean annual diffusive fluxes were 0.21–0.38 mmol·m−2 d−1 for CH4 and 4.90–7.40 μmol·m−2 d−1 for N2O. The CH4 emissions were significantly lower than in most of reference lakes, while the N2O emissions were comparable. Therefore, the human intervention resulted in reduction of CH4 release from LLi but it had minor effect on the N2O. The most likely reason for the low direct fluxes of GHGs from the surface waters was the high flushing rate of the lake and export of dissolved gases to adjacent lakes and canals. Hence, the overall emission from the connected lake and canal system was not mitigated by the man‐made changes to the lake system.
Plain Language Summary
CH4, and N2O are potent greenhouse gases (GHGs). Their emission from lakes is often stimulated by human intervention in the ecosystem. Lake Licheńskie, central Poland, represents a highly disturbed lacustrine system, which, together with a few other lakes, is a part of a cooling system of two electric power plants. Consequently, since 1960s the lake has received considerable discharge of cooling waters which changed lake water chemistry and hydrodynamics. In this study we tried to find out how these multifaceted changes affected greenhouse gas production and emission in the lake. For this purpose we collected water chemistry data and measured diffusive emissions of the GHGs from Lake Licheńskie and a few natural undisturbed lakes in Poland. The latter lakes served as reference lakes. Our data revealed that Lake Licheńskie emitted comparable amounts of N2O albeit less CH4 than natural lakes. This lower emission of CH4 in Lake Licheńskie was a result of the very high flushing rates of the lake by circulating cooling waters. The GHG emissions were most likely released further downwards in the water receiving canals.
Key Points
Lake Licheńskie (Poland) has been highly transformed by long‐term discharge of the effluents from of a power plant
Lake Licheńskie shows lower diffusive emissions of CH4 than natural lakes
Greenhouse gas emissions from Lake Lichenskie are more strongly related to a very high flushing rate than to thermal pollution
Decay of fossil wood (gelification) collected from the middle Miocene 2nd Lusatian lignite seam at the Lubstów open cast mine (Poland) is characterised by its maceral variety, fluorescence intensity ...and cellulose content. Cellulose decomposition leads to lower molar H/C ratio values of the organic matter as indicated by higher total organic carbon (TOC) content of samples characterised by low cellulose content. Biochemical formation of hydrocarbons in the wood due to enhanced microbial activity is evidenced by higher hydrocarbon content in the extracts. Higher relative proportions of
n-alkanes and hopanoids are observed in the hydrocarbon fractions of wood remains characterised by low cellulose yield. The results provide evidence for the formation of these compounds during biogeochemical transformation of organic matter. Hopanoid contents are considered to reflect the activity of aerobic bacteria and/or fungi. Because of enhanced perylene content in the hydrocarbon fractions from gelified wood samples, fungi are considered as the major precursor carriers of this polycyclic aromatic hydrocarbon. The results provide evidence that biomarker composition of fossil wood can be used to trace biochemical transformation processes.
Chemotaxonomical classification of fossil wood fragments as gymnosperms (most probably species of the coniferales families Taxodiaceae/Cupressaceae) are based on the molecular composition of terpenoid hydrocarbons and a mean δ
13C value of −24.5‰. Depletion of gelified samples in
13C as compared to ungelified wood is caused by the effect of progressive decomposition of cellulose. The data indicate that cellulose δ
13C data (mean δ
13C
=
−20.8‰) are also affected by wood decomposition and so only samples with comparable cellulose content should be used for the reconstruction of environmental changes. Inter-species as well as intra-plant variation in carbon isotope differences and of decay resistance between cellulose and lignin have to be taken into account.
Organic-rich samples from the Holocene sedimentary sequence of Lake Sarbsko were investigated to reconstruct variations in the aquatic system in response to environmental change. The aims were to (i) ...identify organic matter (OM) sources, (ii) examine changes in soluble OM composition in relation to fluctuations in limnological conditions and (iii) validate the sensitivity of organic geochemical indicators in tracing environmental changes. Diatom frustules are abundant in all samples. Alginite macerals and terrigenous organic matter further contribute to the sedimentary OM. Organic petrography, total organic carbon (TOC)/N ratio values and high content of biogenic silica (SiO
2
biogenic
) argue for a predominant algal source of OM. In contrast, the
n-alkane distributions, high relative abundance of C
29 steroid hydrocarbons and high content of detrital quartz in the sediments provide evidence for the input of terrigenous material as a major OM source within the basin. The terpenoid biomarker composition indicates a contribution from conifers and angiosperms. From the diterpenoids in the samples a contribution from species of the coniferales family Pinaceae is concluded. TOC/S and Mg/Ca values, as well as steroid/hopanoid concentration ratios, reflect enhanced water salinity in this coastal lake due to ingression of brackish water from the Baltic Sea during the Atlantic and Sub-Atlantic periods. As indicated by the positive relationship between
δ
13C of TOC and Mg/Ca,
δ
13C values are influenced by changing contribution of marine vs. freshwater phytoplankton. Additional isotopic heterogeneity in
δ
13C may result from differences in terrigenous OM supply vs. autochthonous OM production in the lake. The isotopic composition of calcites supports the establishment of freshwater conditions in the lake during the Sub-Boreal period. Pristane/phytane and Fe/Mn ratios are interpreted to reflect differences in the redox conditions. Oxygenation of bottom waters was temporarily variable, with highest levels of oxygen availability during the Sub-Boreal (freshwater lake). High contents of hopanoid hydrocarbons argue for enhanced microbial activity in the water column and sediment. The occurrence of 2β-methyl-hopanes is related to the presence of cyanobacteria or methylotrophic bacteria.
The results demonstrate that in coastal basins of the Baltic Sea sedimentary OM content and composition are a function of the degree of isolation from the sea water. Therefore, organic geochemical data of coastal lake and lagoonal sediments are sensitive indicators for tracing environmental changes during the Holocene.
A three-year field study was conducted in Lake Suminko, Poland, to gain an understanding of the limnological variables that influence the formation and spatial extent of annually laminated sediments ...in the lake. The water body is divided into three depth strata, the mixolimnion, chemocline and monimolimnion, each defined by distinct values of temperature, electrical conductivity and oxygen concentration. Typical for meromictic lakes, the monimolimnion remains perennially anoxic and is rich in dissolved solids and nutrients. The annual pattern of particle flux in Lake Suminko is closely related to biochemical processes in the euphotic zone. During winter months we observed very low accumulation rates of non-carbonaceous matter, while during the rest of the year, three periods of calcite deposition were recorded (April, July–August, and October–November). The periods of high calcite deposition corresponded with algal blooms and oxygen concentration maxima. Two principal factors contribute to meromixis in Lake Suminko: (1) the basin is sheltered, preventing wind mixing, and (2) biochemical processes in the lake associated with high lacustrine productivity. Meromictic conditions must control the formation and preservation of laminated sediments in the lake because preserved laminations occur only in areas where the lake floor lies below monimolimnetic waters.
The present paper provides evidence of the increasing intensity of subsurface saltwater ingressions (SSI) to coastal Lake Sarbsko (northern Poland) during the last few decades. Saltwater ingressions ...to the lake were recognized by spatial and seasonal changes in the concentrations of chlorides in pore waters from the lake surface sediments. Temporal trends in SSI were reconstructed based on diatom proxies from a lake sediment core located within the range of saltwater ingressions. The data showed that subsurface saltwater input to Lake Sarbsko occurs during severe winter storms on the Baltic Sea, when saltwater is pumped to the lake from under the barrier separating the lake from the sea. Due to accelerated sea level rise, increased frequency of storms and lack of ice cover on the Baltic since at least the mid 20th century, saline groundwater supply to the lake has distinctly increased.
This nationwide multicentre study analysed the epidemiology of bacterial, viral and fungal infections in paediatric haematopoietic stem cell transplantation (HSCT) and paediatric haematology and ...oncology (PHO) patients over a period of 24 consecutive months, including incidence, hazard risk and outcome of infections as well as occurrence of multidrug-resistant bacteria. During this period, 308 HSCTs were performed and 1768 children were newly diagnosed for malignancy. Compared to PHO, the risk in HSCT patients was significantly higher for all infections (hazard ratio (HR) 2.7), bacterial (HR 1.4), fungal (HR 3.5) and viral (HR 15.7) infections. The risk was higher in allo- than auto-HSCT for bacterial (HR 1.4), fungal (HR 3.2) and viral (HR 17.7) infections. The incidence of resistant bacteria was higher in HSCT than in PHO patients for both G-negative (72.5% vs. 59.2%) and G-positive (41.4% vs. 20.5%) strains. Cumulative incidence of bacterial, fungal and viral infections in HSCT patients was 33.9, 22.8 and 38.3%, respectively. Cumulative incidence of viral infections in allo-HSCT was 28.0% for cytomegalovirus, 18.5% for BK virus, 15.5% for Epstein-Barr virus, 9.5% for adenovirus, 2.6% for varicella zoster virus, 0.9% for influenza, 0.9% for human herpesvirus 6 and 0.3% for hepatitis B virus. Survival rates from infections were lower in HSCT than in PHO patients in bacterial (96.0 vs. 98.2%), fungal (75.5 vs. 94.6%) and most viral infections. In conclusion, the risk of any infections and the occurrence of resistant bacterial strains in allo-HSCT patients were higher than in auto-HSCT and PHO patients, while the outcome of infections was better in the PHO setting.
The aim was to evaluate the incidence, clinical course, and outcome of adenoviral infection (AdVI) in pediatric patients diagnosed and treated due to cancer and in pediatric recipients of ...hematopoietic stem cell. Over a 72‐month period, all‐in 5599 children with cancer: 2441 patients with hematological malignancy (HM) and 3158 with solid tumors (ST), and 971 patients after transplantation: 741 after allogeneic (allo‐HSCT) and 230 after autologous (auto‐HSCT) were enrolled into the study. Among cancer patients, 67 episodes of AdVI appeared in 63 (1.1%) children, including 45 (1.8%) with HM and 18 (0.6%; P < .001) with ST. Within transplanted patients, AdVIs were responsible for 88 episodes in 81 (8.3%) children (P < .001), including 78 (10.5%) patients after allo‐HSCT and 3 (1.3%) after auto‐HSCT. Time to develop AdVI was short, especially after allo‐HSCT. The most common clinical manifestation in cancer patients was enteritis diagnosed in 63 (94.0%) cases, while among HSCT recipient asymptomatic adenoviremia was found in 36 (40.9%) cases and the most common clinical manifestation was urinary tract infection. Cancer patients with disseminated disease, as well as HSCT recipients with either asymptomatic viremia or disseminated disease, received antiviral treatment. The most commonly used first‐line therapy was cidofovir. None of the cancer patients died due to AdVI, while within HSCT recipients three patients developed disseminated adenoviral disease and died despite antiviral treatment. In cancer patients, AdVIs are rare and associated with very good prognosis even without specific treatment. However, in allo‐HSCT recipients, disseminated disease with fatal outcome is more likely to occur.
Highlights
Low incidence of HAdV causing less severe infections not requiring antiviral therapy but with satisfactory outcome within cancer patients.
In allo‐HSCT recipients disseminated disease requiring antiviral drugs and at risk of fatal outcome is more likely to occur.
Monitoring for HAdV in all patients, and especially in those who underwent AdVI prior to HSCT or had MD or MMUD‐HSCT, at early posttransplantation period should be recommended.
Clostridium difficile
infection (CDI) is one of the most common causes of nosocomial infectious diarrhea in children during anticancer therapy or undergoing hematopoietic stem cell transplantation ...(HSCT) in Europe. Immunosuppression in these patients is a risk factor for CDI. Malignant diseases, age, acute graft-versus-host disease (aGVHD), HLA mismatch, or use of total body irradiation may play an important role in CDI course. The aim of this study was to evaluate the incidence, course, and outcome of CDI in children treated for malignancy or undergoing HSCT. Between 2012 and 2015, a total number of 1846 patients were treated for malignancy in Polish pediatric oncological centers (PHO group) and 342 underwent transplantation (HSCT group). In PHO group, episodes of CDI occurred in 210 patients (14%). The incidence of CDI was higher in patients with hematological malignancies in comparison to that with solid tumors. Patients with acute myeloblastic leukemia had shorter time to episode of CDI than those with acute lymphoblastic leukemia. Patients over 5 years and treated for acute leukemia had more severe clinical course of disease in PHO group. In HSCT group, CDI occurred in 29 (8%) patients. The incidence of CDI was higher in patients transplanted for acute leukemia. The recurrence rate was 14.7% in PHO and 20.7% in HSCT patients. CDI incidence was highest in patients with hematological malignancies. Most of patients experienced mild CDI. Age < 5 years and diagnosis other than acute leukemia were the positive prognostic factors influencing clinical CDI course.
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