In vitro analysis of inflammatory responses following environmental exposure to pharmaceuticals and inland waters

Presence and Reduction of Anthropogenic Substances with UV Light and Oxidizing Disinfectants in Wastewater—A Case Study at Kuopio, Finland

Anthropogenic substances are a major concern due to their potential harmful effects towards aquatic ecosystems. Because wastewater treatment plants (WWTPs) are not designed to remove these substances from wastewater, a part of the anthropogenic substances enter nature via WWTP discharges. During the spring 2019, the occurrence of anthropogenic substances in the municipal wastewater effluent in Kuopio, Finland, was analysed. Furthermore, the capacity of selected disinfection methods to reduce these substances from wastewater was tested. The disinfection methods were ozonation (760 mL min−1) with an OxTube hermetic dissolution method (1), the combined usage of peracetic acid (PAA) (<5 mg L−1) and ultraviolet (UV) disinfection (12 mJ/cm2) (2), and the combined usage of hydrogen peroxide (H2O2) (<10 mg L−1) and UV disinfection (12 mJ/cm2) (3). The substances found at the concentrations over 1 µg L−1 in effluent (N = 3) were cetirizine (5.2 ± 1.3 µg L−1), benzotriazole (BZT) (2.1 ± 0.98 µg L−1), hydrochlorothiazide (1.7 ± 0.2 µg L−1), furosemide (1.6 ± 0.2 µg L−1), lamotrigine (1.5 ± 0.06 µg L−1), diclofenac (DCF) (1.4 ± 0.2 µg L−1), venlafaxine (1.0 ± 0.13 µg L−1) and losartan (0.9 ± 0.2 µg L−1). The reduction (%) with different methods (1, 2, 3) were: cetirizine (99.9, 5.0, NR = no removal), benzotriazole (67.9, NR, NR), hydrochlorothiazide (91.1, 5.9, NR), furosemide (99.7, 5.9, NR), lamotrigine (46.4, NR, 6.7), diclofenac (99.7, 7.1, 16.7), venlafaxine (91.3, NR, 1.1), losartan (99.6, 13.8, NR). Further research concerning the tested disinfection methods is needed in order to fully elucidate their potential for removing anthropogenic substances from purified wastewater.

Theoretical study of the adsorption of analgesic environmental pollutants on pristine and nitrogen-doped graphene nanosheets

Interactions of the analgesic medications dextropropoxyphene (DPP, opioid), paracetamol (PCL, nonnarcotic), tramadol (TDL, nonnarcotic), ibuprofen (IBN, nonsteroidal anti-inflammatory drug (NSAID)), and naproxen (NPX, NSAID) with pristine graphene (GN) and nitrogen-doped GN (NGN; containing only graphitic N atoms) nanosheets were explored using density functional theory (DFT) in the gas and aqueous phases. Calculations in the aqueous phase were performed using the integral equation formalism polarized continuum model (IEFPCM). Calculated geometry-optimized structures, partial atomic charges (determined using Natural Bond Orbital analysis), highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps, work functions (determined using time-dependent DFT), and molecular electrostatic potential plots showed that the adsorption process is physical in nature (viz. physisorption), primarily due to noncovalent π-π and van der Waals interactions. In addition, calculated adsorption energies (ΔEad) were exergonic, indicating that formation of the analgesic/GN and analgesic/NGN complexes is thermodynamically favorable in the gas (ΔEad values for analgesic/GN and analgesic/NGN were in the range of -66.56 kJ mol-1 to -106.78 kJ mol-1) and aqueous phases (ΔEad values for analgesic/GN and analgesic/NGN complexes were in the range of -58.75 kJ mol-1 to -100.46 kJ mol-1). Generally, for GN and NGN, adsorption was more endergonic in the aqueous phase by as much as +10.41 kJ mol-1. Calculated solvation energies (ΔEsolvation) were exergonic for all analgesic/GN complexes (ΔEsolvation values were in the range of -56.50 kJ mol-1 to -66.17 kJ mol-1) and analgesic/NGN complexes (ΔEsolvation values were in the range of -77.26 kJ mol-1 to -87.96 kJ mol-1), with analgesic/NGN complexes exhibiting greater stability in aqueous solutions (∼20 kJ mol-1 more stable). In summary, the results of this theoretical study demonstrate that the adsorption and solvation of analgesics on GN and NGN nanosheets is thermodynamically favorable. In addition, generally, analgesic/NGN complexes exhibit higher adsorption affinities and solvation energies in the gas and aqueous phases. Therefore, GN and NGN nanosheets are potential adsorbents for extracting analgesic contaminants from aqueous environments such as aquatic ecosystems.

Nonsteroidal anti-inflammatory drugs (NSAIDs) cause male-biased sex differentiation in zebrafish

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used pharmaceuticals to treat pain, fever and inflammation. NSAIDs are also known to have many side effects including adverse effects on reproduction in both humans and animals. As NSAIDs usage is not regulated they are frequently detected at high concentrations in the environment. In order to understand the effect of NSAIDs on zebrafish sex differentiation, we used seven different NSAIDs which were either Cox-1 selective, Cox-1 biased, non-selective or COX-2 selective. We show that at higher concentration, NSAIDs are toxic to zebrafish embryo as they lead to mortality and hatching delay. Gene expression analysis following short term exposure of NSAIDs led to downregulation of female specific genes including zp2, vtg2 foxl2 and wnt4. Long term exposure of larvae to environmentally relevant concentrations of Cox-2 selective and non-selective NSAIDs resulted in male-biased sex ratio which confirmed the qRT-PCR analysis. However, the Cox-1 selective acetylsalicylic acid and the Cox-1 biased ketoprofen did not alter sex ratio. The observed male-biased sex ratio could also be due to induction of apoptosis process as the genes including p21 and casp8 were significantly upregulated following exposure to the Cox-2 selective and the non-selective NSAIDs. The present study indicates that NSAIDs alter sex differentiation in zebrafish, primarily through inhibition of Cox-2. This study clearly demonstrates that the use of NSAIDs and their release into the aquatic environment should be carefully monitored to avoid adverse effects to the aquatic organisms.

Furosemide as a functional marker of acute kidney injury in ICU patients: a new role for an old drug

New pharmacokinetics insight suggests that the furosemide pharmacology occurring in ICU patients with AKI is similar, but not equal to that described in chronic stable renal patients. Even if the diuretic response to furosemide is expressed by a steep dose-response curve positively correlated with renal function, pharmacodynamic limitations occur when creatinine clearance is < 20 ml/min or urine output is < 500 ml/12 h. In such cases, other factors specifically due to acute tubular injury can interfere with the furosemide-induced diuretic output. As modality of administration recent reports and metanalysis, even if not conclusive, suggest that for the same given dose a continuous infusion of furosemide was superior in diuretic response. For septic shock patients on CVVHDF where treatment adds an additional clearance of furosemide the maximum diuretic response is achieved by a continuous infusion of 20 mg/h of furosemide. At this infusion rate the reached plasma level was < 20 mg/L, a range considered safe and not ototoxic. Therefore, the severity of AKI establishes whether a patient will respond to furosemide. In this review we summarized all these recent updates, also suggesting that the diuretic response under continuous infusion may allow assessing glomerular and tubular functions with increased reliability than a bolus dose. However, validation studies are still needed to support continuous infusion as a stress test.

What is driving the NF-κB response in environmental water extracts?

In vitro bioassays are increasingly applied for water quality monitoring, with assays indicative of adaptive stress responses commonly included in test batteries. The NF-κB assay is responsive to surface water and wastewater extracts, but the causative compounds are unknown and micropollutants typically found in water do not activate the NF-κB assay. The current study aimed to investigate if co-extracted organic matter and/or endotoxins could cause the NF-κB response in surface water extracts. The effect of model bacterial lipopolysaccharides (LPS) and dissolved organic carbon (DOC) was evaluated in the NF-κB assay both before and after solid-phase extraction (SPE), with 7% effect recovery for LPS and between 7 and 52% effect recovery for DOC observed. The NF-κB response, endotoxin activity, micropollutant concentration and total organic carbon concentration was measured in four surface water extracts. All water extracts showed a response in the NF-κB assay, but the detected micropollutants could not explain the effect. Comparison of predicted bioanalytical equivalent concentrations based on micropollutant, DOC and endotoxin concentrations in surface water with experimental bioanalytical equivalent concentrations suggest that co-extracted endotoxins are the most important drivers of the observed effect, with DOC only having a minor contribution. While in vitro bioassays typically detect mixtures of organic micropollutants, the current study shows that the NF-κB assay can integrate the effects of co-extracted endotoxins. Given that endotoxins can pose a risk for human health, the NF-κB assay is a valuable inclusion in bioanalytical test batteries used for water quality monitoring.

Development of Escherichia coli-based gene expression profiling of sewage sludge leachates

AIMS

The impact of municipal waste on pathogenic micro-organisms released into the environment is a public health concern. This study aims to evaluate the effects of sewage sludge and antibiotic contaminants on stress response, virulence and antibiotic resistance in a pathogenic Escherichia coli.

METHODS AND RESULTS

The effects of sewage sludge leachates on uropathogenic E. coli CFT073 were determined by monitoring the expression of 45 genes associated with antibiotic/metal resistance, stress response and virulence using RT-qPCR. The E. coli gene expression was validated using subinhibitory concentrations of tetracycline and ciprofloxacin. E. coli exposed to sewage sludge or sewage sludge+fly ash leachates altered the expression of five antibiotic and metal resistance, three stress response and two virulence-associated genes. When antibiotics were combined with sludge or sludge+fly ash the antibiotic-associated gene expression was altered.

CONCLUSIONS

E. coli treated with two sludge leachates had distinct gene expression patterns that were altered when the sludge leachates were combined with tetracycline, although to a lesser extent with ciprofloxacin.

SIGNIFICANCE AND IMPACT OF THE STUDY

The E. coli multigene expression analysis is a potential new tool for assessing the effects of pollutants on pathogenic microbes in environmental waters for improved risk assessment.

20 Years of fish immunotoxicology - what we know and where we are

Despite frequent field observations of impaired immune response and increased disease incidence in contaminant-exposed wildlife populations, immunotoxic effects are rarely considered in ecotoxicological risk assessment. The aim of this study was to review the literature on immunotoxic effects of chemicals in fish to quantitatively evaluate (i) which experimental approaches were used to assess immunotoxic effects, (ii) whether immune markers exist to screen for potential immunotoxic activities of chemicals, and (iii) how predictive those parameters are for adverse alterations of fish immunocompetence and disease resistance. A total of 241 publications on fish immunotoxicity were quantitatively analyzed. The main conclusions included: (i) To date, fish immunotoxicology focused mainly on innate immune responses and immunosuppressive effects. (ii) In numerous studies, the experimental conditions are poorly documented, as for instance age or sex of the fish or the rationale for the selected exposure conditions is often missing. (iii) Although a broad variety of parameters were used to assess immunotoxicity, the rationale for the choice of measured parameters was often not given, remaining unclear how they link to the suspected immunotoxic mode of action of the chemicals. (iv) At the current state of knowledge, it is impossible to identify a set of immune parameters that could reliably screen for immunotoxic potentials of chemicals. (v) Similarly, in fish immunotoxicology there is insufficient understanding of how and when chemical-induced modulations of molecular/cellular immune changes relate to adverse alterations of fish immunocompetence, although this would be crucial to include immunotoxicity in ecotoxicological risk assessment.

Transcriptional responses of zebrafish to complex metal mixtures in laboratory studies overestimates the responses observed with environmental water

Metals released into the environment continue to be of concern for human health. However, risk assessment of metal exposure is often based on total metal levels and usually does not take bioavailability data, metal speciation or matrix effects into consideration. The continued development of biological endpoint analyses are therefore of high importance for improved eco-toxicological risk analyses. While there is an on-going debate concerning synergistic or additive effects of low-level mixed exposures there is little environmental data confirming the observations obtained from laboratory experiments. In the present study we utilized qRT-PCR analysis to identify key metal response genes to develop a method for biomonitoring and risk-assessment of metal pollution. The gene expression patterns were determined for juvenile zebrafish exposed to waters from sites down-stream of a closed mining operation. Genes representing different physiological processes including stress response, inflammation, apoptosis, drug metabolism, ion channels and receptors, and genotoxicity were analyzed. The gene expression patterns of zebrafish exposed to laboratory prepared metal mixes were compared to the patterns obtained with fish exposed to the environmental samples with the same metal composition and concentrations. Exposure to environmental samples resulted in fewer alterations in gene expression compared to laboratory mixes. A biotic ligand model (BLM) was used to approximate the bioavailability of the metals in the environmental setting. However, the BLM results were not in agreement with the experimental data, suggesting that the BLM may be overestimating the risk in the environment. The present study therefore supports the inclusion of site-specific biological analyses to complement the present chemical based assays used for environmental risk-assessment.

Oxidative treatment of diclofenac via ferrate(VI) in aqueous media: effect of surfactant additives

The potential reaction of diclofenac (DCF) with ferrate(VI) and influences of coexisting surfactants have not been investigated in depth, and are the focus of this study. The results demonstrated that DCF reacted effectively and rapidly with Fe(VI) and approximately 75% of DCF (0.03 mM) was removed by excess Fe(VI) (0.45 mM) within 10 min. All of the reactions followed pseudo first-order kinetics with respect to DCF and Fe(VI), where the apparent second-order rate constant (k_app) was 5.07 M^-1 s^-1 at pH 9.0. Furthermore, the degradation efficiencies of DCF were clearly dependent on the concentrations of dissolved organic matter additives in the substrate solution. Primarily, inhibitory effects were observed with the samples that contained anionic (sodium dodecyl-benzene sulfonate, SDBS) or non-ionic (Tween-80) surfactants, which have been attributed to the side reactions between Fe(VI) and surfactants, which led to a reduction in the available oxidant for DCF destruction. Furthermore, the addition of a cationic surfactant (cetyltrimethyl ammonium bromide, CTAB) and humic acid (HA) conveyed significantly promotional effects on the DCF-Fe(VI) reaction. The rate enhancement effect for CTAB might be due to micellar surface catalysis, through the Coulomb attraction between the reactants and positively charged surfactants, while the catalytic action for HA resulted from the additional oxidation of Fe(V)/Fe(IV) in the presence of HA. The results provided the basic knowledge required to understand the environmental relevance of DCF oxidation via Fe(VI) in the presence of surfactant additives.

Assessing the potential of pharmaceuticals and their transformation products to cause mutagenic effects: Implications for gene expression profiling

The selection and prioritization of pharmaceuticals and their transformation products for evaluating effects on the environment and human health is a challenging task. One common approach is based on compounds (e.g., mixture composition, concentrations), and another on biology (e.g., relevant endpoint, biological organizational level). Both of these approaches often resemble a Lernaean Hydra-they can create more questions than answers. The present study embraces this complexity, providing an integrated approach toward assessing the potential effects of transformation products of pharmaceuticals by means of mutagenicity, estrogenicity, and differences in the gene expression profiles. Mutagenicity using the tk kinase assay was applied to assess a list of 11 priority pharmaceuticals, namely, atenolol, azithromycin, carbamazepine, diclofenac, ibuprofen, erythromycin, metoprolol, ofloxacin, propranolol, sulfamethoxazole, and trimethoprim. The most mutagenic compounds were found to be β-blockers. In parallel, the photolabile pharmaceuticals were assessed for their mixture effects on mutagenicity (tk assay), estrogenicity (T47D- KBluc assay), and gene expression (microarrays). Interestingly, the mixtures were mutagenic at the µg/L level, indicating a synergistic effect. None of the photolysed mixtures were statistically significantly estrogenic. Gene expression profiling revealed effects related mainly to certain pathways, those of the p53 gene, mitogen-activated protein kinase, alanine, aspartate, and glutamate metabolism, and translation-related (spliceosome). Fourteen phototransformation products are proposed based on the m/z values found through ultra-performance liquid chromatography-tandem mass spectrometry analysis. The transformation routes of the photolysed mixtures indicate a strong similarity with those obtained for each pharmaceutical separately. This finding reinforces the view that transformation products are to be expected in naturally occurring mixtures. Environ Toxicol Chem 2016;35:2753-2764. © 2016 SETAC.

Anticipating the fate and impact of organic environmental contaminants: a new approach applied to the pharmaceutical furosemide

The presence of trace levels of organic contaminants in the environment is currently an environmental concern. When these contaminants are subjected to environmental transformations, environmental transformation products (ETPs) are obtained, whose structures often remain unknown. The absence of information concerning these new compounds makes them unavailable and consequently makes their environmental detection as well as their (eco)toxicological study impossible. This report describes a multidisciplinary approach that seeks to both anticipate the fate and evaluate the impact of organic environmental contaminants. Our approach consists of three steps. First, isolated and fully characterized transformation products (TPs) of the parent molecule are obtained. In the second step, the parent molecule is subjected to environmentally relevant transformations to identify plausible ETPs. The detection of previously characterized TPs allows the concomitant identification of plausible ETPs. The third step is devoted to the toxicological evaluation of the identified plausible ETPs. Such an approach has recently been applied to furosemide and has allowed the identification of its main TPs. This report now seeks to identify and evaluate toxicologically plausible ETPs of this drug, which is also known as an environmental contaminant.

Environmental side effects of pharmaceutical cocktails: what we know and what we should know

Cocktails of pharmaceuticals are released in the environment after human consumption and due to the incomplete removal at the wastewater treatment plants. Pharmaceuticals are considered as contaminants of emerging concern and, a plethora of journal articles addressing their possible adverse effects have been published during the past 20 years. The emphasis during the early years of research within this field, was on the assessment of acute effects of pharmaceuticals applied singly, leading to results regarding their environmental risk, potentially not realistic or relevant to the actual environmental conditions. Only recently has the focus been shifted to chronic exposure and to the assessment of cocktail effects. To this end, this review provides an up-to-date compilation of 57 environmental and human toxicology studies published during 2000-2014 dealing with the adverse effects of pharmaceutical mixtures. The main challenges regarding the design of experiments and the analysis of the results regarding the effects of pharmaceutical mixtures to different biological systems are presented and discussed herein. The gaps of knowledge are critically reviewed highlighting specific future research needs and perspectives.

Contribution of pharmaceuticals, fecal bacteria and endotoxin to the inflammatory responses to inland waters

The increasing contamination of freshwater with pharmaceuticals, surfactants, pesticides and other organic compounds are of major concern. As these contaminants are detected at trace levels in the environment it is important to determine if they elicit biological responses at the observed levels. In addition to chemical pollutants, there is also a concern for increasing levels of bacteria and other microorganisms in freshwater systems. In an earlier study, we observed the activation of inflammatory systems downstream of a wastewater treatment plant (WWTP) in southern Sweden. We also observed that the water contained unidentified components that were pro-inflammatory and potentiated the immune response in human urinary bladder epithelial cells. In order to determine if these effects were unique for the studied site or represent a common response in Swedish water, we have now performed a study on three WWTPs and their recipient waters in central Sweden. Analysis of immune responses in urinary bladder epithelial cells, monocyte-like cells and blood mononuclear cells confirm that these waters activate the immune system as well as induce pro-inflammatory responses. The results indicate that the cytokine profiles correlate to the endotoxin load of the waters rather than to the levels of pharmaceuticals or culturable bacteria load, suggesting that measurements of endotoxin levels and immune responses would be a valuable addition to the analysis of inland waters.

Systematic screening of common wastewater-marking pharmaceuticals in urban aquatic environments: implications for environmental risk control

In this report, we refer to pharmaceuticals that are widespread in the urban aquatic environment and that mainly originate from wastewater treatment plants or non-point source sewage as "wastewater-marking pharmaceuticals" (WWMPs). To some extent, they reflect the condition or trend of water contamination and also contribute to aquatic environmental risk assessment. The method reported here for screening typical WWMPs was proposed based on academic concerns about them and their concentrations present in the urban aquatic environment, as well as their properties of accumulation, persistence, eco-toxicity and related environmental risks caused by them. The screening system consisted of an initial screening system and a further screening system. In the former, pharmaceuticals were categorised into different evaluation levels, and in the latter, each pharmaceutical was given a normalised final evaluation score, which was the sum of every score for its properties of accumulation, persistence, eco-toxicity and environmental risk in the aquatic environment. The system was applied to 126 pharmaceuticals frequently detected in the aquatic environment. In the initial screening procedure, five pharmaceuticals were classified into the "high" category, 16 pharmaceuticals into the "medium" category, 15 pharmaceuticals into the "low" category and 90 pharmaceuticals into the "very low" category. Subsequently, further screening were conducted on 36 pharmaceuticals considered as being of "high", "medium" and "low" categories in the former system. We identified 7 pharmaceuticals with final evaluation scores of 1-10, 10 pharmaceuticals with scores of 11-15, 15 pharmaceuticals with scores from 16 to 20 and 4 pharmaceuticals with scores above 21. The results showed that this screening system could contribute to the effective selection of target WWMPs, which would be important for spatial-temporal dynamics, transference and pollution control of pharmaceuticals in the urban aquatic environment. However, there remains a number of pharmaceutical parameters with measured data gaps, such as organic carbon adsorption coefficients and bioconcentration factors, which, if filled, would improve the accuracy of the screening system.

Selection of reliable biomarkers from PCR array analyses using relative distance computational model: methodology and proof-of-concept study

It is increasingly evident about the difficulty to monitor chemical exposure through biomarkers as almost all the biomarkers so far proposed are not specific for any individual chemical. In this proof-of-concept study, adult male zebrafish (Danio rerio) were exposed to 5 or 25 µg/L 17β-estradiol (E2), 100 µg/L lindane, 5 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 15 mg/L arsenic for 96 h, and the expression profiles of 59 genes involved in 7 pathways plus 2 well characterized biomarker genes, vtg1 (vitellogenin1) and cyp1a1 (cytochrome P450 1A1), were examined. Relative distance (RD) computational model was developed to screen favorable genes and generate appropriate gene sets for the differentiation of chemicals/concentrations selected. Our results demonstrated that the known biomarker genes were not always good candidates for the differentiation of pair of chemicals/concentrations, and other genes had higher potentials in some cases. Furthermore, the differentiation of 5 chemicals/concentrations examined were attainable using expression data of various gene sets, and the best combination was the set consisting of 50 genes; however, as few as two genes (e.g. vtg1 and hspa5 [heat shock protein 5]) were sufficient to differentiate the five chemical/concentration groups in the present test. These observations suggest that multi-parameter arrays should be more reliable for biomonitoring of chemical exposure than traditional biomarkers, and the RD computational model provides an effective tool for the selection of parameters and generation of parameter sets.

An Environmental Risk Assessment for Human-Use Trimethoprim in European Surface Waters

An environmental risk assessment (ERA) for the aquatic compartment in Europe from human use was developed for the old antibiotic Trimethoprim (TMP), comparing exposure and effects. The exposure assessment is based on European risk assessment default values on one hand and is refined with documented human use figures in Western Europe from IMS Health and measured removal in wastewater treatment on the other. The resulting predicted environmental concentrations (PECs) are compared with measured environmental concentrations (MECs) from Europe, based on a large dataset incorporating more than 1800 single MECs. On the effects side, available chronic ecotoxicity data from the literature were complemented by additional, new chronic results for fish and other organisms. Based on these data, chronic-based deterministic predicted no effect concentrations (PNECs) were derived as well as two different probabilistic PNEC ranges. The ERA compares surface water PECs and MECs with aquatic PNECs for TMP. Based on all the risk characterization ratios (PEC÷PNEC as well as MEC÷PNEC) and risk graphs, there is no significant risk to surface waters.