Novel technique for the ultra-sensitive detection of hazardous contaminants using an innovative sensor integrated with a bioreactor.

This study introduces an evaluation methodology tailored for bioreactors, with the aim of assessing the stress experienced by algae due to harmful contaminants released from antifouling (AF) paints. We present an online monitoring system equipped with an ultra-sensitive sensor that conducts non-invasive measurements of algal culture's optical density and physiological stage through chlorophyll fluorescence signals. By coupling the ultra-sensitive sensor with flash-induced chlorophyll fluorescence, we examined the dynamic fluorescence changes in the green microalga Chlamydomonas reinhardtii when exposed to biocides. Over a 24-h observation period, increasing concentrations of biocides led to a decrease in photosynthetic activity. Notably, a substantial reduction in the maximum quantum yield of primary photochemistry (FV/FM) was observed within the first hour of exposure. Subsequently, we detected a partial recovery in FV/FM; however, this recovery remained 50% lower than that of the controls. Integrating the advanced submersible sensor with fluorescence decay kinetics offered a comprehensive perspective on the dynamic alterations in algal cells under the exposure to biocides released from antifouling coatings. The analysis of fluorescence relaxation kinetics revealed a significant shortening of the fast and middle phases,  along with an increase in the duration of the slow phase, for the coating with the highest levels of biocides. Combining automated culturing and measuring methods, this approach has demonstrated its effectiveness as an ultrasensitive and non-invasive tool for monitoring the physiology of photosynthetic cultures. This is particularly valuable in the context of studying microalgae and their early responses to various environmental conditions, as well as the potential to develop an AF system with minimal harm to the environment.

Assessing health risks in bottled water: chemical compounds and their impact on human health.

Bottled mineral and spring water constitute one of the main sources of drinking water. Relevant legal acts in each country individually regulate the highest permitted concentrations of harmful substances in these waters. However, current regulations do not take into account newly emerging contaminants such as BPA. Analysis of the chemical composition of 72 bottled waters from the Polish market showed that undesirable elements occur in quantities that do not exceed the maximum permissible concentrations. Special attention should be paid to bottled therapeutic water, which may contain elevated concentrations of some micronutrients, such as Al, B, Ba, Fe, Mn, or Sr contributing to the pattern of health risk with excessive consumption of this type of water. The presence of BPA was confirmed in 25 tested waters. The calculated hazard index values showed that the most exposed group are children up to 12 years of age. The greatest attention should be paid to waters with high mineralisation, for which the calculated risk values are the highest.

Metal leakage from orthodontic appliances chemically alters enamel surface during experimental in vitro simulated treatment.

Human enamel is composed mainly of apatite. This mineral of sorption properties is susceptible to chemical changes, which in turn affect its resistance to dissolution. This study aimed to investigate whether metal leakage from orthodontic appliances chemically alters the enamel surface during an in vitro simulated orthodontic treatment. Totally 107 human enamel samples were subjected to the simulation involving metal appliances and cyclic pH fluctuations over a period of 12 months in four complimentary experiments. The average concentrations and distribution of Fe, Cr, Ni, Ti and Cu within the enamel before and after the experiments were examined using ICP‒MS and LA‒ICP‒MS techniques. The samples exposed to the interaction with metal appliances exhibited a significant increase in average Fe, Cr and Ni (Kruskal-Wallis, p < 0.002) content in comparison to the control group. The outer layer, narrow fissures and points of contact with the metal components showed increased concentrations of Fe, Ti, Ni and Cr after simulated treatment, conversely to the enamel sealed with an adhesive system. It has been concluded that metal leakage from orthodontic appliances chemically alters enamel surface and microlesions during experimental in vitro simulated treatment.

Towards a better practice in water sampling: Case studies on used in practice geothermal waters.

The state-of-the-art of sampling procedures is specified in appropriate guidelines, but there is a permanent need to minimise the risk to the water sample quality, in particular for waters with specific characteristics such as geothermal waters. Improper sampling leads to erroneous results and, consequently, e.g. increased uncertainty in models of geochemical processes (scaling, corrosion) in geothermal installations, aquifer geothermometry, or environmental assessments. The impact of the applied filters (nylon, PVDF, MCE), containers (HDPE, borosilicate glass) and preservation on concentration of 34 major, minor and trace elements was studied for the samples of two geothermal waters used in practice. The results of replicated chemical analyses in duplicated samples of geothermal waters and deionized water blanks were subjected to statistical analyses, including nonparametric tests (Kruskal-Wallis, Dunn's, Kolmogorov-Smirnov, Mann-Whitney U, Wald-Wolfowitz). The PVC housing of the used MCE syringe filters contaminates water samples with Sb. Borosilicate glass increases Al, Cu, Pb and Se concentrations in samples. Acidification protects against changes in concentrations of numerous elements (i.a. Al, B, Ba, Cu, Fe, Ni, Pb) in the solution. Results of analysis performed indicated that using nylon membrane filter and HDPE (properly precleaned to wash out extractables) containers for thermal water sampling is recommended.

Thermal Analysis of Stomatal Response under Salinity and High Light.

A non-destructive thermal imaging method was used to study the stomatal response of salt-treated Arabidopsis thaliana plants to excessive light. The plants were exposed to different levels of salt concentrations (0, 75, 150, and 220 mM NaCl). Time-dependent thermograms showed the changes in the temperature distribution over the lamina and provided new insights into the acute light-induced temporary response of Arabidopsis under short-term salinity. The initial response of plants, which was associated with stomatal aperture, revealed an exponential growth in temperature kinetics. Using a single-exponential function, we estimated the time constants of thermal courses of plants exposed to acute high light. The saline-induced impairment in stomatal movement caused the reduced stomatal conductance and transpiration rate. Limited transpiration of NaCl-treated plants resulted in an increased rosette temperature and decreased thermal time constants as compared to the controls. The net CO2 assimilation rate decreased for plants exposed to 220 mM NaCl; in the case of 75 mM NaCl treatment, an increase was observed. A significant decline in the maximal quantum yield of photosystem II under excessive light was noticeable for the control and NaCl-treated plants. This study provides evidence that thermal imaging as a highly sensitive technique may be useful for analyzing the stomatal aperture and movement under dynamic environmental conditions.

Fate of selected neonicotinoid insecticides in soil-water systems: Current state of the art and knowledge gaps.

The occurrence of emerging contaminants, such as: personal care products, medicines, pharmaceuticals, pesticides, and their transformation products in the environment is of concern for human health and aquatic ecosystems due to their high persistence, toxicity and potential to bioaccumulation. Among pesticides, the main attention and thus our focus is on neonicotinoids: acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam, which are widely used classes of insecticides in agriculture. Determining the associated risk to humans and ecosystems from neonicotinoid insecticides requires detailed understanding of their fate and transport in the environment which is complex and includes diverse pathways and processes depending on environmental compartments in which they occur. This paper critically reviews the current state of the art about processes, parameters and phenomena influencing the fate of neonicotinoid insecticides in soil-water systems (i.e. soil and groundwater), and reveals existing knowledge gaps. Sorption, biodegradation, chemical transformations of neonicotinoid insecticides in the soil and leaching to the groundwater, as well as groundwater/surface water interactions are highlighted, as they determine their further migration from sources, through soils to groundwater systems and then to other environmental compartments posing ecological and human risks. A number of key knowledge gaps in fate of neonicotinoid insecticides in soil-water systems are identified, that concern mostly processes and pathways occurring in the groundwater, and require further research to assess the associated risk to humans and ecosystems.

Redox potential research in the field of balneochemistry: case study on equilibrium approach to bioactive elements in therapeutic waters.

In some countries (e.g. Poland, Czechia, Slovakia, Russia, Germany), oxidation-reduction potential (ORP) measurements are required to document the quality of groundwater which are planned to be used as therapeutic waters. ORP is still rarely studied and not fully availed in therapeutic water research. Studies of ORP in various types of therapeutic, mineral and thermal waters in sites of Poland integrated with geochemical equilibrium approach were employed to characterize two redox-sensitive and bioactive elements, i.e. iron and sulphur. Studied waters present reducing conditions (EH between - 406 and - 41 mV) at outflow or extraction sites; however, they significantly differ in terms of total dissolved solids, temperature, and iron, sulphur(II) and sulphate concentrations. These result in recognizable differences, e.g. in terms of saturation state with respect to aquifer rock minerals and the dominating forms of occurrence of elements studied disclosed on the stability field diagrams. Considering the methodological determinants, ORP orchestrated with geochemical modelling tools might be successfully applied for studying natural linkages between various groundwater in natural systems, protecting the therapeutic water resource, and identifying the changes of water quality both at exploitation sites (springs, wells) and treatment places.

LC-MS/MS method validation for determination of selected neonicotinoids in groundwater for the purpose of a column experiment.

The work was carried out to develop and validate a method based on liquid chromatography tandem mass spectrometry (LC-MS/MS) for the simultaneous detection and quantification of five neonicotinoid insecticides: acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam in groundwater samples for the purpose of a further column experiment. This experiment will be used to analyze breakthrough curves of neonicotinoids under a saturated water flow to set transport parameters, where the reliability of the results of chemical analysis plays an important role. The validation was performed in a concentration range from 0.09 µg L-1 to 100 µg L-1 using an Infinity 1290 (Agilent, USA) chromatograph coupled with a QTrap 5500 mass spectrometer (Sciex, Canada). The calibration curves were obtained on the basis of the results of six standard solution analyses. Linearity was not lower than 0.998. The limit of detection was set at the lowest concentration which can be determined with an acceptable accuracy and precision. All pesticides had recoveries in the range 85-109% with relative standard deviation values less than 8.1%. The estimated measurement uncertainty did not exceed 30%, so the LC-MS/MS method fits for the intended purpose.

Selected problems with boron determination in water treatment processes. Part I: comparison of the reference methods for ICP-MS and ICP-OES determinations.

The aim of the study was to compare the two reference methods for the determination of boron in water samples and further assess the impact of the method of preparation of samples for analysis on the results obtained. Samples were collected during different desalination processes, ultrafiltration and the double reverse osmosis system, connected in series. From each point, samples were prepared in four different ways: the first was filtered (through a membrane filter of 0.45 µm) and acidified (using 1 mL ultrapure nitric acid for each 100 mL of samples) (FA), the second was unfiltered and not acidified (UFNA), the third was filtered but not acidified (FNA), and finally, the fourth was unfiltered but acidified (UFA). All samples were analysed using two analytical methods: inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). The results obtained were compared and correlated, and the differences between them were studied. The results show that there are statistically significant differences between the concentrations obtained using the ICP-MS and ICP-OES techniques regardless of the methods of sampling preparation (sample filtration and preservation). Finally, both the ICP-MS and ICP-OES methods can be used for determination of the boron concentration in water. The differences in the boron concentrations obtained using these two methods can be caused by several high-level concentrations in selected whole-water digestates and some matrix effects. Higher concentrations of iron (from 1 to 20 mg/L) than chromium (0.02-1 mg/L) in the samples analysed can influence boron determination. When iron concentrations are high, we can observe the emission spectrum as a double joined and overlapping peak.