BPA – an endocrine disrupting compound in water used for drinking purposes,a snapshot from South Poland

Bisphenol A (BPA) is a chemical produced in large quantities for use primarily in the production of polycarbonate plastics and epoxy resins. As an endocrine-disrupting compound, it has been included in the list of substances requiring special supervision as a very high-risk substance due to its toxic influence on reproduction. BPA with a reference value of 0.01 μg/L was included in the Drinking Water Directive revision (DWD 2018). This paper presents the results of preliminary studies aimed at identifying the occurrence of BPA in different types of water, i.a. groundwater captured with house wells or flowing wells in a selected location in southern Po-land. These waters are commonly used as a source of water intended for human consumption and their quality is not regularly controlled. Additional tests were carried out for surface water, as well as water from springs used for drinking purposes. The authors also analysed tap water from various sources, i.e. surface and groundwater, as the final product of the drinking water production cycle. The results indicate the presence of BPA in water and the necessity of a detailed study on the risk of the BPA occurring in groundwater, especially in domestic wells

A probabilistic approach to assessment of the quality of drinking water

Knowledge of uncertainty in analytical results is of prime importance in assessments of compliance with requirements set out for the quality of water intended for human consumption. Assessments of drinking water quality can be performed using either a deterministic or a probabilistic method. In the former approach, every single result is referred directly to the parametric value, while in the probabilistic method uncertainty related to analytical results is taken into account during the decision-making process. In the present research, laboratory uncertainty and uncertainty determined on the basis of results of analyses of duplicate samples collected in two Polish cities were compared and used in the probabilistic approach of water quality assessment. Using the probabilistic method, more results were considered to be “above the parametric value”. Most excesses were observed when the maximum allowable uncertainty as set out in the Regulation of the Minister of Health of 7 December 2017 was used, which is due to the highest values of these uncertainties. The lowest values above parametric values in the probabilistic approach were observed when measurement uncertainty was considered

Identification of transport parameters of chlorides in different soils on the basis of column studies

Knowledge of transport patterns of chemicals in groundwater is essential for environmental assessment of their potential impact. In the present study, the mobility of a chloride tracer injected into three different soils was investigated, using column experiments. The column tests were performed under steady-state conditions to determine parameters of chloride migration through soils. Based on breakthrough curves, pore-water velocity, dispersion coefficient and dispersivity constant were calculated for each soil sample using CXTFIT/STANMOD software. Pore-water velocity was in the range of 0.31 cm/min for fine sand, to 0.35 cm/min for silty sand and to 0.40 cm/min for vari-grained sand. The highest values of dispersion coefficient and dispersivity constant were observed for silty sand (0.55 cm2 /min and 1.55 cm, respectively), while the lowest value was found for fine sand (0.059 cm2 /min and 0.19 cm, respectively). Column experiments for chlorides (conservative tracer) are a preliminary stage for further research which will be undertaken to investigate migration parameters of selected neonicotinoids (reactive tracers) through different soils

Methodological aspects concerning sampling and determination of total selenium and selenium species in geothermal waters

The work presents the results of geothermal water sample analysis with respect to the determination of total selenium concentration. For this purpose, geothermal water (GT) samples were collected from three different intakes (GT-1, GT-2, GT-3) with similar temperatures of about 85ºC. Tests were carried out to see if the methodology of sample preparation influenced total selenium concentration during analysis by inductively coupled plasma mass spectrometry (ICP-MS). Samples (raw and filtered) were preserved with nitric acid (HNO3) and mineralised in the laboratory. From the data obtained it was found that there is no significant difference between total selenium concentration in raw and filtered samples. Following mineralisation, the concentrations in the samples were below the limit of detection or limit of quantification. While different analytical steps or procedures are applied, the results of total selenium concentration can vary. Furthermore, high-performance liquid chromatography coupled with ICP-MS was used for the identification of selenium species. The results revealed that hexavalent selenium – Se(VI) – in the geothermal water was found only in samples collected from the GT-2 and GT-3 intakes

Methodological aspects of pH and EC measurements in geothermal water

A proper methodology for collecting samples of geothermal water makes it possible not only to determine the hydrochemical characteristics of the water, but also to assess its temporal and spatial variability. The knowledge about the concentration of selected elements as well as the values of field measurements can help to indicate their impact on other environments and the processes that occur in a geothermal system. An important issue is the quality of the results obtained from in-situ measurements of unstable parameters, i.a. pH and electrical conductivity (EC). The results of measurements presented in the paper were completed with the use of three different devices in hot and cooled raw geothermal water (field test). The research was performed during two seasons of increased (winter) and lower (summer) exploitation of geothermal water. The percentage difference between EC at temperatures of 22ºC and 75ºC was 3.27%; however, for the pH the observed percentage difference was only 0.26%. An additional experiment was carried out on a laboratory scale to indicate the influence of temperature changes on pH and EC measurements

Dynamic effects and large – amplitude motion in Jacobi and Poincaré shape transitions in atomic nuclei

The Jacobi and Poincaré shape transitions are very promising way to investigate the shape of the nucleus. The presented here quasi-phenomenological approach allows to estimate the experimental conditions which are necessary to observe these phenomena. The static energy minimum gives the spin ranges and the fissility of atomic nuclei soft for the shape transitions and available experimentally. Dynamical effects taken into account through the solving collective Hamiltonian for zero-point vibration estimation, changes the spin rages for the shape transitions. The static deformation of the nucleus constrained by the minimum of energy for given spin has been enhanced to dynamical nuclear shapes permitted by the zero point energy. The large amplitude vibrations around the static deformation gives the ensemble of nuclear shapes possible to be observed

The role of Mcl-1 in S. aureus-induced cytoprotection of infected macrophages

As a facultative intracellular pathogen, Staphylococcus aureus invades macrophages and then promotes the cytoprotection of infected cells thus stabilizing safe niche for silent persistence. This process occurs through the upregulation of crucial antiapoptotic genes, in particular, myeloid cell leukemia-1 (MCL-1). Here, we investigated the underlying mechanism and signal transduction pathways leading to increased MCL-1 expression in infected macrophages. Live S. aureus not only stimulated de novo synthesis of Mcl-1, but also prolonged the stability of this antiapoptotic protein. Consistent with this, we proved a crucial role of Mcl-1 in S. aureus-induced cytoprotection, since silencing of MCL1 by siRNA profoundly reversed the cytoprotection of infected cells leading to apoptosis. Increased MCL1 expression in infected cells was associated with enhanced NF B activation and subsequent IL-6 secretion, since the inhibition of both NF B and IL-6 signalling pathways abrogated Mcl-1 induction and cytoprotection. Finally, we confirmed our observation in vivo in murine model of septic arthritis showing the association between the severity of arthritis and Mcl-1 expression. Therefore, we propose that S. aureus is hijacking the Mcl-1-dependent inhibition of apoptosis to prevent the elimination of infected host cells, thus allowing the intracellular persistence of the pathogen, its dissemination by infected macrophages, and the progression of staphylococci diseases

Health risk assessment resulting from the presence of Legionella bacteria in domestic hot water in public buildings – the results of a pilot study

The aim of the study was to assess the risk posed by Legionella bacteria in a public building in Krakow. An old building with internal installation risers of different ages, as well as draw-off points of different types, was selected for testing. Samples were collected during two campaigns. In one sample of the first series of tests, no bacteria were found. During the second series of tests, no Legionella bacilli were found in just one sample and in one sample only 4 colony-forming units were detected. At the remaining draw-off points (water taps), the bacteria count detected were greater than the maximum threshold allowed by legal regulations (admissible threshold for public utility buildings – 100 cfu/100 mL). No morphological differences were observed with respect to the occurrence of specific serogroups. In 14 samples, Legionella pneumophila serogroups 2–14 were found, while the Legionella pneumophila serogroup 1 was only found in one sample. The risk assessment was also carried out based on a semi-quantitative risk matrix approach and as a quantitative microbial risk assessment. The risk matrix approach was successfully implemented for the recognition of the potential risk associated with the Legionella occurrence in a water system. The calculated annual cumulative risk is high. The research shows that even if the weekly inhalation exposure dose (and therefore the calculated risk) is high, the number of Legionella pneumophila illness cases found can be equal to zero. This is probably due to the large uncertainty associated with QMRA determination. The size of the room in which the contaminated water is used also affects the possibility of infection

The occurrence of microplastics in freshwater systems – preliminary results from Krakow (Poland)

The results of research conducted in recent years indicates that microplastic particles are widely distributed in the aquatic environment. The investigations are mostly focused on marine waters and there is still a lack of information about their presence in both surface water and groundwater. In this paper, preliminary results of research conducted in Poland are presented. Different types of water samples were collected. Five litres of each sample were filtered through 0.4 μm glass fibre filters. In the first stage, visual identification was conducted using a stereomicroscope. Additionally, some interesting fragments were examined by means of SEM/EDS method. In the case of rivers water samples, which were characterized by a high content of organic matter and minerals, the visibility of microplastics could be reduced. In the sample from the Vistula River, some particles similar to microplastics were found. In the groundwater samples, some blue and green particles which supposed to be plastic were found by the stereomicroscope. Additional analysis with the DXR Raman Microscope method gave no clear results. The samples were too small and the plastic particles were very dispersed which prevented correct analysis. SEM analysis showed irregularly shaped particles which were considered to be microplastics. Considering the chemical composition, carbon predominated

Human Health Risk Assessment of Trace Elements in Tap Waterand the Factors Influencing Its Value

(1) Background: The influence of tap water fittings construction and internal pipe-work on the release of heavy metals was investigated. (2) Methods: A statistical approach was applied for the examination of the chemistry of tap water in five different cities in southern Poland. In total, 500 samples were collected (from 100 to 101 samples in each city). The sampling protocol included information on the construction of the water supply network and the physicochemical parameters of measured tap water. (3) Results: The statistical analysis allowed to extract the crucial factors that affect the concentrations of trace elements in tap water. Age of connection, age of tap, age of pipe-work as well as material of connection, material of pipe-work and material of appliance reveal the most significant variability of concentrations observed for As, Al, Cd, Cu, Fe, Mn, Pb, and Zn. Calculated cancer risks (CRs) decrease with the following order of analysed elements Ni > Cd > Cr > As = Pb and can be associated with the factors that affect the appearance of such elements in tap water. The hazard index (HI) was evaluated as negligible in 59.1% of the sampling points and low in 40.1% for adults. For children, a high risk was observed in 0.2%, medium in 9.0%, negligible in 0.4%, and low for the rest of the analysed samples