Analysis of the Effect of Photo and Hydrodegradation on the Surface Morphology and Mechanical Properties of Composites Based on PLA and PHI Modified with Natural Particles.

Biodegradable polymer materials are increasingly used in the packaging industry due to their good properties and low environmental impact. Therefore, the work was performed on the injection molding of the bio-based composites of polylactide (PLA) and polyhydroxyalcanates (PHI) modified with two phases: reinforcing (walnut shell flour and cellulose) and coloring (beta carotene and anthocyanin). The produced materials were subjected to wide mechanical characteristics-tensile, flexural, and fatigue tests. Additionally, the influence of photo and hydrodegradation on the change of the surface structure and mechanical properties of the composites was assessed. The addition of natural fillers contributed to the improvement of the stiffness of the tested composites. PHI composites withstood a higher number of cycles during cyclic loading, but the stress values obtained in the static tensile test were higher for PLA composites. Moreover, a clear change of color was observed after both the photo and hydrodegradation process for all tested materials; however, after the degradation processes, the filler-modified materials underwent greater discoloration. For the composites based on PHI, the type of degradation did not affect the mechanical properties. On the other hand, for PLA composites, hydrolytic degradation contributed to a higher decrease in properties-the decrease in tensile strength for unmodified PLA after photodegradation was 4%, while after hydrodegradation it was 24%.

Mixture toxicity of six pharmaceuticals towards Aliivibrio fischeri, Daphnia magna, and Lemna minor.

As the knowledge on the joint effects of pharmaceuticals towards different non-target organisms is still limited, the aim of our study was to evaluate the toxicity of mixtures of pharmaceuticals, as well as their baseline toxicity towards three selected organisms, namely the bioluminescent bacteria Aliivibrio fischeri, the crustacean Daphnia magna, and the duckweed Lemna minor. Different mixtures composed of three up to five pharmaceuticals having the same or different mechanisms of action in terms of their therapeutic activity (non-steroidal anti-inflammatory drugs, opioid analgesic, antibacterial and anti-epileptic drugs) were investigated. The observed EC50s were compared with those predicted using the concentration addition (CA) and independent action (IA) models. In general, the EC50 values for mixtures predicted with the CA model were lower than those obtained with the IA model, although, in some cases, test predictions of these two models were almost identical. Most of the experimentally determined EC50 values for the specific mixtures were slightly higher than those predicted with the CA model; hence, a less than additive effect was noted. Based on the obtained results, it might be concluded that the CA model assumes the worst-case scenario and gives overall closer predictions; therefore, it should be recommended also for modeling the mixture toxicity of pharmaceuticals with different modes of action.

Sorption of pharmaceuticals on the surface of microplastics.

The presence of both pollutants: microplastics and pharmaceutical residues in various environmental compartments is an issue of increasing concern. Available literature data indicates that microplastics can affect the environmental distribution and transport of e.g. persistent organic pollutants (POPs) through sorption interactions, concentrating them at a given point and thus influencing the environmental risks represented by the sorbent and sorbate pair. Therefore, their potential to change the fate of other contaminants in the environment, such as pharmaceuticals, is worth investigating. The aim of this study was to evaluate the sorption capacity of nine pharmaceuticals, commonly used in human and veterinary medicine, which constitute known ubiquitous water pollutants: enrofloxacin (ENR), ciprofloxacin (CIP), norfloxacin (NOR), 5-fluorouracil (5-FU), methotrexate (MET), flubendazole (FLU), fenbendazole (FEN), propranolol (PRO) and nadolol (NAD), on the surface of the most often identified microscopic plastic particles in the aquatic environment, i.e. polypropylene (PP), low density polyethylene (LD-PE), high density polyethylene (HD-PE) and polyvinyl chloride (PVC). The obtained results suggest a complex nature of sorption, including both hydrophobic and electrostatic interactions. However, since the ionic strength of the medium was found to be a significant factor influencing the sorption potential, minute interactions are observed in conditions common for the natural environment.

Anti-inflammatory drugs in the Vistula River following the failure of the Warsaw sewage collection system in 2019.

At the end of August 2019, in Warsaw, the sewage collection system of the Wastewater Treatment Plant malfunctioned. During the subsequent 12 days, over 3.6 million m3 of untreated sewage was introduced from the damaged collector directly into the Vistula River. It is one of the biggest known failures of its kind in the world so far. In this study we investigated to what extent the incident contributed to the increased discharge of anti-inflammatory drugs into the environment. The study covered the section from the point of discharge to the city of Torun (ca. 170 km downstream). It was found that in the river waters downstream of the damaged collector, the concentrations of selected pharmaceuticals increased considerably in comparison with the waters upstream of the collector. The highest concentrations were observed for paracetamol (102.9 µg/L), ibuprofen (5.3 µg/L) and diclofenac (4.8 µg/L). We also measured to what extent and at what rate these pollutants were distributed along the river. The effects of the incident were observed in further parts of the river after 16 days. In the study we also detected elevated concentrations of ibuprofen and diclofenac in the bottom sediments collected 6 weeks after the failure. Measurements of the levels of pharmaceuticals in estuarial and marine waters in the vicinity of the mouth of the Vistula River indicate that the incident did not significantly increase the load of these pollutants in the waters of the southern Baltic Sea.

Ecotoxicity screening evaluation of selected pharmaceuticals and their transformation products towards various organisms.

The intensive development of medical science has led to an increase in the availability and use of pharmaceutical products. However, nowadays, most of scientific attention has been paid to the native forms of pharmaceuticals, while the transformation products (TPs) of these substances, understood herein as metabolites, degradation products, and selected enantiomers, remain largely unexplored in terms of their characterization, presence, fate and effects within the natural environment. Therefore, the main aim of this study was to evaluate the toxicity of seven native compounds belonging to different therapeutic groups (non-steroidal anti-inflammatory drugs, opioid analgesics, beta-blockers, antibacterial and anti-epileptic drugs), along with the toxicity of their 13 most important TPs. For this purpose, an ecotoxicological test battery, consisting of five organisms of different biological organization was used. The obtained data shows that, in general, the toxicity of TPs to the tested organisms was similar or lower compared to their parent compounds. However, for example, significantly higher toxicity of the R form of ibuprofen to algae and duckweed, as well as a higher toxicity of the R form of naproxen to luminescent bacteria, was observed, proving that the risk associated with the presence of drug TPs in the environment should not be neglected.

Mixture toxicity of flubendazole and fenbendazole to Daphnia magna.

Nowadays, residual amounts of many pharmaceuticals can be found in various environmental compartments including surface and ground waters, soils and sediments as well as biota. Even though they undergo degradability, their environmental discharge is relatively continuous, thus they may be regarded as quasi-persistent contaminants, and are also frequently regarded as emerging organic pollutants. Benzimidazoles, especially flubendazole (FLU) and fenbendazole (FEN), represent two anthelmintic drugs belonging to this group. Although their presence in environmental matrices has been reported, there is relatively little data concerning their (eco)toxicological impact. Furthermore, no data is available on their mixture toxicity. FLU and FEN have been found to have a strong impact on an environmentally important non-target organism - Daphnia magna. Moreover, these compounds are usually present in the environment as a part of pharmaceutical mixtures. Therefore, there is a need to evaluate their mixture toxicity, which was the main aim of this study. Single substance toxicity tests were carried out in parallel with mixture studies of FLU and FEN, with the application of two well established concepts of Concentration Addition (CA) and Independent Action (IA). As a result, both models (CA and IA) were found to underestimate the toxicity of mixtures, however CA yielded more accurate predictions.

Bioaccumulation and analytics of pharmaceutical residues in the environment: A review.

The presence of pharmaceutical residues in various environmental compartments is an issue of increasing concern. The widespread occurrence of these compounds in water and soil samples has been demonstrated in a number of analytical studies. However, the data about their concentrations in biota samples is scarce. Moreover, the trophic transfer of pharmaceuticals remains largely unexplored, despite increasing evidence of the potential bioaccumulation of those compounds. Therefore, the main aim of this review is to present an overview of the current state of data about the bioaccumulation and analytical methodologies used for the determination of pharmaceutical residues in biota samples. This work focuses on the most commonly found pharmaceuticals in the environment: antibiotics, analgesic and anti-inflammatory drugs, steroid hormones, antihypertensives and antidepressants. We do hope that the collected data will allow a better understanding of pharmaceutical pollution and the exposure of non-target organisms. However, although impressive progress has undoubtedly been made, in order to fully understand the behavior of these chemicals in the environment, there are still numerous gaps to be filled in our overall knowledge in this field.

Toxicity of anthelmintic drugs (fenbendazole and flubendazole) to aquatic organisms.

Flubendazole (FLU) and fenbendazole (FEN) belong to benzimidazoles-pharmaceuticals widely used in veterinary and human medicine for the treatment of intestinal parasites as well as for the treatment of systemic worm infections. In recent years, usage of these drugs increased, which resulted in a larger contamination of the environment and possible negative effects on biota. Hence, in our research, we investigated an aquatic ecotoxicity of these pharmaceuticals towards: marine bacteria (Vibrio fischeri), green algae (Scenedesmus vacuolatus), duckweed (Lemna minor) and crustacean (Daphnia magna). Ecotoxicity tests were combined with chemical analysis in order to investigate the actual exposure concentration of the compounds used in the experiment as well as to stability and adsorption studies. As a result, study evaluating sensitivity of different aquatic organisms to these compounds and new ecotoxicological data is presented. The strongest negative impact of FLU and FEN was observed to D. magna.

Development of sensitive and reliable LC-MS/MS methods for the determination of three fluoroquinolones in water and fish tissue samples and preliminary environmental risk assessment of their presence in two rivers in northern Poland.

Antibiotic consumption (e.g. fluoroquinolones (FQs)) and, as a consequence, their presence in the environment, have received a lot of attention in the last several years due to increasing numbers of diseases and infections that are becoming resistant to traditional treatments for both humans and animals. In addition, even though antibiotics are safe for human and veterinary usage, ecosystems may be exposed to these substances. In this study, analytical methods for determining enrofloxacin (ENR), norfloxacin (NOR) and ciprofloxacin (CIP) in water samples and fish tissue based on the LC-MS/MS technique were developed and validated. As there is no data available concerning the risks posed by antibiotics in Poland, the proposed methods were applied for monitoring drug presence in environmental samples collected from two rivers in northern Poland. Evaluations of the ecotoxicity of ENR, NOR and CIP towards four different species of aquatic organisms: marine bacteria (Vibrio fischeri), green algae (Scenedesmus vacuolatus), duckweed (Lemna minor) and crustacean (Daphnia magna), were also carried out. All the investigated compounds were detected at least once in the survey. NOR was found to be the most ubiquitous drug with concentrations of up to 442.8 ng L(-1). Moreover, it was established that L. minor is the most sensitive species to the investigated drugs (EC50NOR = 0.13 mg L(-1), EC50ENR = 0.22 mg L(-1) and EC50CIP = 0.34 mg L(-1)). The calculated risk quotient (RQ) values confirmed that the concentrations of the investigated FQs in the environmental samples were at a level of moderate environmental risk (1

Beta-blockers in the environment: part II. Ecotoxicity study.

The increasing consumption of beta-blockers (BB) has caused their presence in the environment to become more noticeable. Even though BB are safe for human and veterinary usage, ecosystems may be exposed to these substances. In this study, three selected BB: propranolol, metoprolol and nadolol were subjected to ecotoxicity study. Ecotoxicity evaluation was based on a flexible ecotoxicological test battery including organisms, representing different trophic levels and complexity: marine bacteria (Vibrio fischeri), soil/sediment bacteria (Arthrobacter globiformis), green algae (Scenedesmus vacuolatus) and duckweed (Lemna minor). All the ecotoxicological studies were supported by instrumental analysis to measure deviation between nominal and real test concentrations. Based on toxicological data from the green algae test (S. vacuolatus) propranolol and metoprolol can be considered to be harmful to aquatic organisms. However, sorption explicitly inhibits the hazardous effects of BB, therefore the risks posed by these compounds for the environment are of minor importance.

Beta-blockers in the environment: part I. Mobility and hydrolysis study.

Beta-blockers (BB) are one of the most widely used pharmaceuticals whose presence in different environmental compartments has already been proven in concentrations of even up to a few µg L(-1). However, our knowledge of their fate in the environment is still scarce. To obtain a better understanding on the environmental behavior of three selected BB comprehensive laboratory experiments assessing their mobility and hydrolytic stability has been conducted. Propranolol, metoprolol and nadolol--the most commonly consumed and detected in environmental samples--were selected as representatives of this group of pharmaceuticals. The objectives of our research were: (i) evaluation of the sorption potential and an explanation of the sorption mechanisms of these compounds onto soil and clay mineral (kaolinite); and (ii) investigation of the hydrolytic stability of these BB according to OECD 111. This comprehensive study supports the Environmental Risk Assessment of these pharmaceuticals.

The use of chromatographic techniques for the separation and the identification of insect lipids.

The paper presents the state of knowledge on the chromatographic techniques used in the analysis of insect lipids. Lipids are one of the forms of protection against entomopathogenic fungi. Their composition may include a number of different compounds, such as long chain hydrocarbons, waxes, alcohols, aldehydes and free fatty acids. These compounds may be presented in different amounts depending on the species of insects, living environment, lifestyle, seasons, etc. The most commonly used techniques in the analysis of lipids of insects are: gas chromatography, high performance liquid chromatography, and combined techniques such as gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). Compounds present in the cuticular lipids of insects may serve diverse functions such as minimizing transpiration. It was also found that extracts of insects possess antifungal effects. Determination of lipid profiles and biological activity of the identified compounds can effectively contribute to the knowledge of the defense mechanisms of insects, and thus, impact the development of new methods of combating harmful insects.