Assessment of Lemna minor (duckweed) and Corbicula fluminea (freshwater clam) as potential indicators of contaminated aquatic ecosystems: responses to presence of psychoactive drug mixtures

Ion-exchange chromatography in the assessment of environmental pollution with chlortetracycline

Chemical substances such as drugs pose a threat to the environment. One of the substances recorded in soil and water is chlortetracycline, an antibiotic used in veterinary medicine. Plants exposed to such xenobiotics show changes in the content of biogenic amines. An analytical technique - ion exchange chromatography is used to assess their content. The occurrence of these active compounds is used to determine the degree of environmental pollution with chemical substances. The study aimed to evaluate the toxicity of chlortetracycline (CTC) at concentrations of 0; 0.05; 0.1; 0.2 0.5;1; 2; 3; and 5 mM towards the test organism Lemna minor, and determine the content of biogenic amines in the plant tissues. The content of biogenic amines was analyzed by ion-exchange chromatography with post-column ninhydrin derivatization and photometric detection. The Lemna test proved that increasing concentrations of CTC had a toxic effect on the plants. It was calculated that the Lowest Observed Effects Concentration (LOEC) of CTC at >0.04 mM and >0.05 mM was phytotoxic to L. minor growth and yield. It was determined that the levels of histamine, tyramine, and cadaverine exhibited an increase, reaching 1.04, 1.90, and 3.10 µg g-1 of tissue at 2.00 mM CTC. Simultaneously, spermine and putrescine increased to 1.21 and 3.89 µg g-1 of tissue at concentrations of 0.10 and 0.50 mM of the drug. Conversely, the study revealed an over 88 % reduction in spermidine in plants at 5 mM of CTC. Using ion-exchange chromatography, analysis of biogenic amines, particularly spermidine and cadaverine, highlighted these intra-tissue compounds as sensitive biomarkers for water contamination with the tested drug. This research confirmed that the Lemna test is effective for assessing CTC toxicity and that ion-exchange chromatography is useful for evaluating environmental pollution by this antibiotic.

Mechanisms, toxicity and optimal conditions - research on the removal of benzotriazoles from water using Wolffia arrhiza

In the presented work, phytoremediation with the use of floating plant Wolffia arrhiza (L.) Horkel ex Wimm. was proposed as a method of removing the selected benzotriazoles (BTRs): 1H-benzotriazole (1H-BTR), 4-methyl-1H-benzotriazole (4M-BTR), 5-methyl-1H-benzotriazole (5M-BTR) and 5-chlorobenzotriazole (5Cl-BTR) from water. The efficiency of phytoremediation depends on three factors: daily time of exposure to light, pH of the model solution, and the amount of plans. Using a design of experiment (DoE) methods the following optimal values were selected: plant amount 1.8 g, light exposure 13 h and pH 7 per 100 mL of the model solution. It was found that the loss of BTRs in optimal conditions ranged from 92 to 100 % except for 4M-BTR, for which only 23 % of removal was achieved after 14 days of cultivation of W. arrhiza. The half-life values for studied compounds ranged from 0.98 days for 5Cl-BTR to 36.19 for 4M-BTR. The observed rapid vanishing of 5M-BTR is supposed by the simultaneous transformation of 5M-BTR into 4M-BTR. The detailed study of BTRs degradation pointed that the plant uptake is mainly responsible for the benzotriazoles concentration decrease. Toxicity tests showed that the tested organic compounds induce oxidative stress in W. arrhiza, which manifested among others, in reduced levels of chlorophyll in cultures with benzotriazoles compared to control.

Anxiety in Duckweed–Metabolism and Effect of Diazepam on Lemna minor

The fate of pharmaceuticals in the human body, from their absorption to excretion is well studied. However, medication often leaves the patient’s body in an unchanged or metabolised, yet still active, form. Diazepam and its metabolites, ranging up to 100 µg/L, have been detected in surface waters worldwide; therefore, the question of its influence on model aquatic plants, such as duckweed (Lemna minor), needs to be addressed. Lemna was cultivated in a Steinberg medium containing diazepam in three concentrations—0.2, 20, and 2000 µg/L. The activity of superoxide dismutase (SOD) and catalase (CAT), leaf count, mass, and the fluorescence quantum yield of photosynthesis were assessed. The medium was also analysed by LC-MS/MS to determine the concentration of diazepam metabolites. Our results show no negative impact of diazepam on Lemna minor, even in concentrations significantly higher than those that are ecotoxicologically relevant. On the contrary, the influence of diazepam on Lemna suggests growth stimulation and a similarity to the effect diazepam has on the human body. The comparison to the human body may be accurate because γ-Aminobutyric acid-like (GABA-like) receptors responsible for the effect in humans have also been recently described in plants. Therefore, our results can open an interesting scientific area, indicating that GABA receptors and interference with benzodiazepines are evolutionarily much older than previously anticipated. This could help to answer more questions related to the reaction of aquatic organisms to micropollutants such as psychopharmaceuticals.

Growth, pigment changes, and photosystem II activity in the aquatic macrophyte Lemna minor exposed to bisphenol A

As a result of its high production, bisphenol A (BPA) has become ubiquitous in aquatic and terrestrial habitats. In this study, we investigated the toxicity of BPA at 10 mg L^-1 on Lemna minor after 7 days of exposure under controlled conditions according to ISO 20079. BPA statistically reduced the total frond number and frond area, while frond number per colony was significantly elevated in BPA-treated group. However, no change was recorded in root number, while root length was significantly reduced by BPA. BPA also decreased the content of Chl a, Chl b, Chl a + b, and carotenoid by 36%, 44%, 38%, and 32%, respectively, versus the control leading to a decrease in the quantum yield of photosystem II. In addition, non-photochemical quenching (NPQ) values were 2.4- and 4.5-fold higher in light than in dark conditions for control and BPA-treated plants, respectively. Thus, there is a significant activation (61.8%; p<0.01) of PSII photoprotection mechanism (NPQ) in BPA-treated plants compared to control but without removing the negative effect of BPA on PSII. The total amount of soluble sugars was reduced by 40% compared to control, and starch accumulation was mainly observed in fronds exposed to BPA. Even if the response patterns of Lemna minor based on fresh and dry weight measurements were less sensitive in our experiment conditions, further studies should be addressed since BPA represents a threat to the dynamic equilibrium governing aquatic ecosystems.

Molecular Methods as Potential Tools in Ecohydrological Studies on Emerging Contaminants in Freshwater Ecosystems

Contaminants of emerging concern (CECs) present a threat to the functioning of freshwater ecosystems. Their spread in the environment can affect both plant and animal health. Ecohydrology serves as a solution for assessment approaches (i.e., threat identification, ecotoxicological assessment, and cause–effect relationship analysis) and solution approaches (i.e., the elaboration of nature-based solutions: NBSs), mitigating the toxic effect of CECs. However, the wide array of potential molecular analyses are not fully exploited in ecohydrological research. Although the number of publications considering the application of molecular tools in freshwater studies has been steadily growing, no paper has reviewed the most prominent studies on the potential use of molecular technologies in ecohydrology. Therefore, the present article examines the role of molecular methods and novel omics technologies as essential tools in the ecohydrological approach to CECs management in freshwater ecosystems. It considers DNA, RNA and protein-level analyses intended to provide an overall view on the response of organisms to stress factors. This is compliant with the principles of ecohydrology, which emphasize the importance of multiple indicator measurements and correlation analysis in order to determine the effects of contaminants, their interaction with other environmental factors and their removal using NBS in freshwater ecosystems.

Single and combined effects of carbamazepine and copper on nervous and antioxidant systems of zebrafish (Danio rerio)

Various pollutants co-exist in the aquatic environment such as carbamazepine (CBZ) and copper (Cu), which can cause complex effects on inhabiting organisms. The toxic impacts of the single substance have been studied extensively. However, the studies about their combined adverse impacts are not enough. In the present study, zebrafish were exposed to environmental relevant concentrations of CBZ (1, 10, and 100 μg/L), Cu (0.5, 5, and 10 μg/L) and the mixtures (1 μg/L CBZ + 0.5 μg/L Cu, 10 μg/L CBZ + 5 μg/L Cu, 100 μg/L CBZ + 10 μg/L Cu) for 45 days, the effects on nervous and antioxidant systems of zebrafish were investigated. The results demonstrated that, in comparison with single exposure group, the combined presence of CBZ and Cu exacerbated the effect of antioxidant system (the ability of inhibition of hydroxyl radicals (IHR), superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST)) but not nervous system (Acetylcholinesterase [AChE]). The qPCR results supported the changes of corresponding enzymes activities. Hepatic histopathological analysis verified the results of biomarkers. Our work illustrated that the toxicity of mixed pollutants is very complicated, which cannot simply be inferred from the toxicity of single pollutant, and calls for more co-exposure experiments to better understanding of the co-effects of pollutants on aquatic organisms.

Evaluation of morpho-physiological traits and contaminant accumulation ability in Lemna minor L. treated with increasing perfluorooctanoic acid (PFOA) concentrations under laboratory conditions

There is increasing concern about the effects of releasing emerging contaminants (i.e. endocrine-disrupting chemicals, pharmaceuticals, personal-care products and flame retardants) into the environment. Particular attention is being paid to perfluoroalkyl substances (PFAS) because of their persistence and bioaccumulation, especially in the aquatic environment. In this paper, we present results of a study aimed at evaluating the effects of different perfluorooctanoic acid (PFOA) concentrations (2, 20 and 200 μg/L) on morpho-physiological traits in Lemna minor L. plants. The accumulation of PFOA in the plant's tissues was also monitored. L. minor was selected as a model plant for ecotoxicological studies, and we performed a seven-day assay for this investigation. The results highlight the lack of inhibitory effects on biometric parameters such as mean frond area, total frond number, multiplication rate, doubling time of frond number and average specific growth rate, for each of tested PFOA concentrations. Also, at photosynthetic level, physiological measurements showed that chlorophyll content and electron transport rate (ETR) were not affected by the exposure to PFOA. Remarkably, the chlorophyll fluorescence images, used for the first time in a study on PFOA, evidenced no impairment to the photosynthetic efficiency, measured by the maximum quantum yield of photosystem II (PSII) photochemistry (Fv/Fm), the quantum efficiency of PSII photochemistry (ΦPSII) and the non-photochemical quenching (NPQ) over the leaf surface of PFOA-treated plants, in comparison to control. Quantification of PFOA in the growth medium at the end of the seven-day test revealed no statistically different concentrations in plates with or without L. minor plants. We detected increasing PFOA accumulation in plant tissues, in accordance with the PFOA concentrations in the medium. Therefore, the L. minor plants were capable of taking up and accumulating PFOA. The ecological impact of the environmentally relevant PFOA concentrations tested in this work on biological organisms of the aquatic environment is discussed.

Improving performance of a pharmacy in a Romanian hospital through implementation of an internal management control system

According to general principles of good practice, adopted at the international level, quality control is a key function in management and not just a simple means of verification. In a clinic or hospital pharmacy, the chief pharmacist has the training and authority to take the control measures necessary to develop and implement an Internal Managerial Control System (IMCS). The present article analyzes and describes the case of the County Hospital of Oradea, Romania, and presents how the IMCS was adopted and integrated. Quality assessment in the health services takes place via an accreditation process and quality certification, as well as through an internal audit of the hospital pharmacy. The authors report a retrospective and descriptive study carried out from 2012 to 2017, analyzing how current legislative standards are applied. The IMCS in the hospital pharmacy is a dynamic process of continuous transformation, permanently adapted to hospital requirements, achieved under the direction of the chief pharmacist and involving all pharmacy employees, as well as through good coordination practices applied by hospital management. In this specific case, the IMCS features 11 annually updated compliance standards, classed under the headings of work procedures, risk register, job descriptions and staff training. The pharmacy's good practice model for IMCS development, was adopted by all of the hospital's sectors, services and departments.

Contribution of trace metallic elements to weakly contaminated lacustrine sediments: effects on benthic and pelagic organisms through multi-species laboratory bioassays

Surficial sediments exhibit higher levels of contamination than overlying water, especially from persistent contaminants such as trace metallic elements (TMEs). While sediments could in turn act as sources of contamination for the water column, their ecotoxicology is yet rarely assessed in a multi-compartments perspective. This study aims at assessing the response of benthic and pelagic organisms exposed to weakly contaminated sediments using a multi-species laboratory assay by focusing on TMEs (Cd, Cr, Cu, Ni, Pb, and Zn) contamination. Chironomus riparius larvae, Daphnia magna, and Lemna minor were simultaneously exposed for 10 days to six sediments sampled from the littoral of a large French lake (Lake Bourget). The endpoints consisted in the survival and growth rates and the bioconcentration factor (BCF). Significant negative relationships between sediment TME concentrations and survival rates of C. riparius and growth rates of C. riparius and D. magna suggested that both benthic and pelagic macro-invertebrates were impacted by sediment contamination, which was not observed in L. minor. Significant relationships of the sediment with the internal TME concentrations were positive while negative with the BCFs, suggesting an increase in biological regulation processes in all organisms with the increase of sediment TME concentrations. These results underline the importance of including both benthic and pelagic organisms in ecotoxicological assessment of low contaminated sediments and the relevance of the relationship BCFs/sediment contamination as prior biomarkers than higher life history traits.

Environmental risk assessment of psychoactive drugs in the aquatic environment

The consumption of psychoactive pharmaceuticals has increased worldwide, and wastewater treatment plants are not able to eliminate them from the effluent. An extensive review was carried out to assess the environmental risk (ERA model) based on secondary data about potential impacts on non-target organisms of seven psychoactive drugs consumed worldwide (alprazolam, bromazepam, citalopram, clonazepam, diazepam, lorazepam, and oxazepam). Risk quotients (RQs) were calculated according to the European Medicines Agency (EMA) on ERA of Medicinal Products For Human Use based on (i) the predicted and measured environmental concentrations (PEC and MEC, respectively) of the psychoactive drug in surface water, groundwater, and wastewater effluent and (ii) the predicted no-effect concentration (PNEC) derived from ecotoxicological assays or ECOSAR software. Furthermore, this study reviews and discusses non-standardized ecotoxicity assays, such as sublethal and behavioral effects on different organisms. In total, 903 MEC entries of psychoactive drugs and 162 data on ecotoxicological assays were gathered from the literature survey addressing behavioral effects (115), acute/chronic effects (35), and sublethal effects (12). Citalopram and diazepam were the only substances that are likely to pose an environmental risk (RQ > 1) to surface waters. Even though there is considerable amount of data on behavioral effects of psychoactive drugs to aquatic species, results are currently not integrated into the EMA risk assessment framework. The large amount of data on psychoactive drug concentrations and effects on non-target organisms collected, interpreted, and discussed in the present study should be used as a baseline for future improvement of ERA strategies.

Gene expression and genotoxicity in Manila clam (Ruditapes philippinarum) modulated by sediment contamination and lagoon dynamics in the Po river delta

The lagoons of the Po River delta are potentially exposed to complex mixtures of contaminants, nevertheless, there is a substantial lack of information about the biological effects of these contaminants in the Po delta lagoons. These environments are highly dynamic and the interactions between chemical and environmental stressors could prevent the proper identification of biological effects and their causes. In this study, we aimed to disentangle such interactions focusing on Manila clams, previously exposed to six lagoons of the Po delta, adopting three complementary tools: a) the detailed description via modelling techniques of lagoon dynamics for salinity and water temperature; b) the response sensitivity of a number of target genes (ahr, cyp4, ρ-gst, σ-gst, hsp22, hsp70, hsp90, ikb, dbh, ach, cat, Mn-sod, Cu/Zn-sod, cyp-a, flp, grx, TrxP) investigated in clam digestive glands by Real Time PCR; and c) the relevance of DNA adducts determined in clams as markers of exposure to genotoxic chemicals. The lagoons showed specific dynamics, and two of them (Marinetta and Canarin) could induce osmotic stress. A group of genes (ahr, cyp4, Mn-sod, σ-gst, hsp-22, cyp-a, TrxP) seemed to be associated with overall lagoon characteristics as may be described by salinity and its variations. Lagoon modelling and a second group of genes (hsp70, hsp90, cat, ikb, ach, grx, Cu/Zn-sod) also suggested that moderate increases of river discharge may imply worse exposure conditions. Oxidative stress seemed to be associated with such events but it was slightly evident also under normal exposure conditions. DNA adduct formation was mainly associated with overwhelmed antioxidant defences (e.g. low Cu/Zn-sod) or seemingly with their lack of response in due time. In Po delta lagoons, Manila clam can be affected by chemical and environmental factors which can contribute to induce oxidative stress, DNA adduct formation and, ultimately, to affect clam condition and health.

Biological effects of citalopram in a suspended sediment-water system on Daphnia magna

Suspended sediment (SPS) plays an important role in the aquatic ecosystems. Selective serotonin uptake inhibitors (SSRIs) are commonly used antidepressants and are frequently detected in aquatic environments. However, the biological effects of SSRIs in the presence of SPS are not well understood. To fill this gap, an SPS-water system was constructed to investigate the effects of citalopram (CIT) on Daphnia magna in the presence of SPS with different concentrations (0.1, 0.5, 1 g l^-1) and organic carbon contents (0.5, 1, 1.5, 2%). A dialysis bag was applied in the exposure system to control the same dissolved concentration of CIT and prevent SPS from entering into the bag. The dissolved CIT concentration obviously decreased in the SPS-water system during the exposure period. The presence of SPS significantly increased the immobilization of D. magna, and the immobilization rates were positively correlated with the SPS concentration and negatively correlated with the organic carbon content in SPS. For a single exposure, CIT significantly increased superoxide dismutase (SOD) activity and inhibited acetylcholinesterase (AChE) activity in D. magna, while SPS itself did not change the SOD and AChE activities. In the SPS-water system, SOD activity was significantly suppressed, indicating that the SPS-CIT combination could result in oxidative damage. However, SPS did not enhance the neurotoxicity of D. magna that was induced by CIT. These results suggest that SPS exerts a vital role on the biological effects of CIT and the contaminants sorbed on SPS should be taken into consideration.