Suspect screening workflow comparison for the analysis of organic xenobiotics in environmental water samples

Sample preparation for suspect screening of persistent, mobile and toxic substances and their phase II metabolites in human urine by mixed-mode liquid chromatography

Persistent, mobile and toxic substances have drawn attention nowadays due to their particular properties, but they are overlooked in human monitorization works, limiting the knowledge of the human exposome. In that sense, human urine is an interesting matrix since not only parent compounds are eliminated, but also their phase II metabolites that could act as biomarkers. In this work, 11 sample preparation procedures involving preconcentration were tested to ensure maximum analytical coverage in human urine using mixed-mode liquid chromatography coupled with high-resolution tandem mass spectrometry. The optimized procedure consisted of a combination of solid-phase extraction and salt-assisted liquid-liquid extraction and it was employed for suspect screening. Additionally, a non-discriminatory dilute-and-shoot approach was also evaluated. After evaluating the workflow in terms of limits of identification and type II errors (i.e., false negatives), a pooled urine sample was analysed. From a list of 1450 suspects and in-silico simulated 1568 phase II metabolites (i.e. sulphates, glucuronides, and glycines), 44 and 14 substances were annotated, respectively. Most of the screened suspects were diverse industrial chemicals, but biocides, natural products and pharmaceuticals were also detected. Lastly, the complementarity of the sample preparation procedures, columns, and analysis conditions was assessed. As a result, dilute-and-shoot and the Acclaim Trinity P1 column at pH = 3 (positive ionization) and pH = 7 (negative ionization) allowed the maximum coverage since almost 70 % of the total suspects could be screened using those conditions.

Chinmedomics: a potent tool for the evaluation of traditional Chinese medicine efficacy and identification of its active components

As an important part of medical science, Traditional Chinese Medicine (TCM) attracts much public attention due to its multi-target and multi-pathway characteristics in treating diseases. However, the limitations of traditional research methods pose a dilemma for the evaluation of clinical efficacy, the discovery of active ingredients and the elucidation of the mechanism of action. Therefore, innovative approaches that are in line with the characteristics of TCM theory and clinical practice are urgently needed. Chinmendomics, a newly emerging strategy for evaluating the efficacy of TCM, is proposed. This strategy combines systems biology, serum pharmacochemistry of TCM and bioinformatics to evaluate the efficacy of TCM with a holistic view by accurately identifying syndrome biomarkers and monitoring their complex metabolic processes intervened by TCM, and finding the agents associated with the metabolic course of pharmacodynamic biomarkers by constructing a bioinformatics-based correlation network model to further reveal the interaction between agents and pharmacodynamic targets. In this article, we review the recent progress of Chinmedomics to promote its application in the modernisation and internationalisation of TCM.

Development and evaluation of a comprehensive workflow for suspect screening of exposome-related xenobiotics and phase II metabolites in diverse human biofluids

Suspect and non-target screening (SNTS) methods are being promoted in order to decode the human exposome since a wide chemical space can be analysed in a diversity of human biofluids. However, SNTS approaches in the exposomics field are infra-studied in comparison to environmental or food monitoring studies. In this work, a comprehensive suspect screening workflow was developed to annotate exposome-related xenobiotics and phase II metabolites in diverse human biofluids. Precisely, human urine, breast milk, saliva and ovarian follicular fluid were employed as samples and analysed by means of ultra-high performance liquid chromatography coupled with high resolution tandem mass spectrometry (UHPLC-HRMS/MS). To automate the workflow, the "peak rating" parameter implemented in Compound Discoverer 3.3.2 was optimized to avoid time-consuming manual revision of chromatographic peaks. In addition, the presence of endogenous molecules that might interfere with the annotation of xenobiotics was carefully studied as the employment of inclusion and exclusion suspect lists. To evaluate the workflow, limits of identification (LOIs) and type I and II errors (i.e., false positives and negatives, respectively) were calculated in both standard solutions and spiked biofluids using 161 xenobiotics and 22 metabolites. For 80.3 % of the suspects, LOIs below 15 ng/mL were achieved. In terms of type I errors, only two cases were identified in standards and spiked samples. Regarding type II errors, the 7.7 % errors accounted in standards increased to 17.4 % in real samples. Lastly, the use of an inclusion list for endogens was favoured since it avoided 18.7 % of potential type I errors, while the exclusion list caused 7.2 % of type II errors despite making the annotation workflow less time-consuming.

Evaluating membrane bioreactor treatment for the elimination of emerging contaminants using different analytical methods

Since wastewater treatment plants (WWTPs) were not originally designed to eliminate contaminants of emerging concern (CECs), alternative strategies like membrane bioreactor (MBR) technology are gaining importance in achieving effective CEC removal and minimising their environmental impact. In this study, composite wastewater samples were collected from the biggest WWTP in the Basque Country (Galindo, Biscay) and the performance of two secondary treatments (i.e. conventional activated sludge treatment, CAS, and MBR) was assessed. The combination of a suspect screening approach using liquid chromatography tandem high-resolution mass spectrometry (LC-HRMS) and multitarget analysis by gas chromatography-mass spectrometry (GC-MS) allowed the detection of approximately 200 compounds in the WWTP effluents. The estimated removal efficiencies (REs) revealed that only 16 micropollutants exhibited enhanced removal by MBR treatment (RE > 70% or 40 - 60%). The environmental risk posed by the non-eliminated compounds after both treatments remained similar, being anthracene, clarithromycin, bis(2-ethylhexyl) phthalate (DEHP) and dilantin the most concerning pollutants (RQ > 1). The Microtox® bioassay confirmed the MBR's efficiency in removing baseline toxicity, while suggesting a similar performance of CAS treatment. These minimal differences between treatments call into question the worthiness of MBR treatment and emphasise the need to seek more efficient alternative treatment methods.

Development of an analytical method for the simultaneous determination of 50 semi-volatile organic contaminants in wastewaters

This work describes the development of a robust analytical methodology for the simultaneous determination of 50 semi-volatile organic compounds (SVOCs) in wastewater effluent samples by solid-phase extraction (SPE) followed by gas chromatography coupled to mass spectrometry (GC-MS) analysis. In this work, we studied extensively whether the validated SPE method used for the analysis of polar compounds in wastewaters could be extended to the analysis of non-polar compounds in the same analytical run. To that aim, the effect of different organic solvents in the SPE process (i.e., sample conditioning prior to SPE, elution solvent and evaporation steps) was evaluated. In this sense, the addition of methanol to wastewater samples before the extraction, the use of hexane:toluene (4:1, v/v) mixture for the quantitative elution of target compounds, and the addition of isooctane during the evaporation were required to minimize analyte losses during SPE and enhance extraction yields. Overall, the developed methodology showed a good performance for the determination of 50 SVOCs, and was further applied to the analysis of real wastewater effluent samples.•A validated SPE method for polar compounds was extended to the analysis of non-polar compounds.•Elution with hex:tol (4:1, v/v) and the addition of isooctane during the evaporation yield good recoveries.•The developed methodology was suitable for the determination of 50 SVOCs in aqueous samples.

Environmentally relevant concentrations of antidepressant mirtazapine impair the neurodevelopment of zebrafish (Danio rerio)

Mirtazapine is a commonly prescribed antidepressant and has been found widespread in aquatic environments. However, its toxicities to aquatic organisms has rarely been explored. Herein, we conducted a comprehensive study on the developmental effects of mirtazapine on early life stages of zebrafish at environmentally relevant concentrations (3.9 ng/L and 43.5 ng/L). Out of the endpoints measured, spontaneous contraction of embryos at 24 h post fertilization (hpf) and hatching rate and heart rate of embryos at 50 hpf and 56 hpf, respectively, were significantly affected. In light-dark transition behavior test, mirtazapine significantly reduced the swimming frequency and swimming speed of embryos at both concentrations of 3.9 ng/L and 43.5 ng/L. Furthermore, the total swimming distances in dark conditions were also significantly reduced. Transcriptomic analysis was further conducted. It demonstrated that the decreased neural activities in embryos may be associated with altered epinephrine and neuregulin signaling. The present results fill a data gap regarding the exposure of fish to mirtazapine at environmentally relevant concentrations and provide new insights into the neurotoxic mechanisms of mirtazapine exposure.

Metabolomics to study the sublethal effects of diazepam and irbesartan on glass eels (Anguilla anguilla)

Since glass eels are continuously exposed to contamination throughout their migratory journey in estuaries, to a certain extent the fall in the population of this endangered species might be attributed to this exposure, which is especially acute in estuaries under high urban pressure. In this work, metabolomics was used to address the main objective of this study, to evaluate the effects of two pharmaceuticals previously identified as potential concerning chemicals for fish (diazepam and irbesartan) on glass eels. An exposure experiment to diazepam, irbesartan and their mixture was carried out over 7 days followed by 7 days of depuration phase. After exposure, glass eels were individually sacrificed using a lethal bath of anesthesia, and then an unbiased sample extraction method was used to extract separately the polar metabolome and the lipidome. The polar metabolome was submitted to targeted and non-targeted analysis, whereas for the lipidome only the non-targeted analysis was carried out. A combined strategy using partial least squares discriminant analysis and univariate and multivariate statistical analysis (ANOVA, ASCA, t-test, and fold-change analysis) was used to identify the metabolites altered in the exposed groups with respect to the control group. The results of the polar metabolome analysis revealed that glass eels exposed to the diazepam-irbesartan mixture were the most impacted ones, with altered levels for 11 metabolites, some of them belonging to the energetic metabolism, which was confirmed to be sensitive to these contaminants. Additionally, the dysregulation of the levels of twelve lipids, most of them with energetic and structural functions, was also found after exposure to the mixture, which might be related to oxidative stress, inflammation, or alteration of the energetic metabolism.

Comprehensive micropollutant characterization of wastewater during Covid-19 crisis in 2020: Suspect screening and environmental risk prioritization strategy

Micropollutants monitoring in wastewater can serve as a picture of what is consuming society and how it can impact the aquatic environment. In this work, a suspect screening approach was used to detect the known and unknown contaminants in wastewater samples collected from two wastewater treatment plants (WWTPs) located in the Basque Country (Crispijana in Alava, and Galindo in Vizcaya) during two weekly sampling campaigns, which included the months from April to July 2020, part of the confinement period caused by COVID-19. To that aim, high-resolution mass spectrometry was used to collect full-scan data-dependent tandem mass spectra from the water samples using a suspect database containing >40,000 chemical substances. The presence of > 80 contaminants was confirmed (level 1) and quantified in both WWTP samples, while at least 47 compounds were tentatively identified (2a). Among the contaminants of concern, an increase in the occurrence of some compounds used for COVID-19 disease treatment, such as lopinavir and hydroxychloroquine, was observed during the lockdown. A prioritization strategy for environmental risk assessment was carried out considering only the compounds quantified in the effluents of Crispijana and Galindo WWTPs. The compounds were scored based on the removal efficiency, estimated persistency, bioconcentration factor, mobility, toxicity potential and frequency of detection in the samples. With this approach, 33 compounds (e.g. amantadine, clozapine or lopinavir) were found to be considered key contaminants in the analyzed samples based on their concentration, occurrence and potential toxicity. Additionally, antimicrobial (RQ-AR) and antiviral (EDRP) risk of certain compounds was evaluated, where ciprofloxacin and fluconazole represented medium risk for antibiotic resistance (1 > RQ-AR > 0.1) in the aquatic ecosystems. Regarding mixture toxicity, the computed sum of toxic unit values of the different effluents (> 1) suggest that interactions between the compounds need to be considered for future environmental risk assessments.

Spatio-seasonal patterns of the impact of wastewater treatment plant effluents on antibiotic resistance in river sediments

There is a growing concern about the risk of antibiotic resistance emergence and dissemination in the environment. Here, we evaluated the spatio-seasonal patterns of the impact of wastewater treatment plant (WWTP) effluents on antibiotic resistance in river sediments. To this purpose, sediment samples were collected in three river basins affected by WWTP effluents in wet (high-water period) and dry (low-water period) hydrological conditions at three locations: (i) upstream the WWTPs; (ii) WWTP effluent discharge points (effluent outfall); and (iii) downstream the WWTPs (500 m downriver from the effluent outfall). The absolute and relative abundances of 9 antibiotic resistance genes (ARGs), 3 mobile genetic element (MGE) genes, and 4 metal resistance genes (MRGs) were quantified in sediment samples, as well as a variety of physicochemical parameters, metal contents, and antibiotic concentrations in both sediment and water samples. In sediments, significantly higher relative abundances of most genes were observed in downstream vs. upstream sampling points. Seasonal changes (higher values in low-water vs. high-water period) were observed for both ARG absolute and relative abundances in sediment samples. Chemical data revealed the contribution of effluents from WWTPs as a source of antibiotic and metal contamination in river ecosystems. The observed positive correlations between ARG and MGE genes relative abundances point out to the role of horizontal gene transfer in antibiotic resistance dissemination. Monitoring plans that take into consideration spatio-temporal patterns must be implemented to properly assess the environmental fate of WWTP-related emerging contaminants in river ecosystems.

Unravelling the occurrence of trace contaminants in surface waters using semi-quantitative suspected non-target screening analyses

Several classes of anthropogenic chemicals such as pesticides and pharmaceuticals are frequently used in human-related life activities and are discharged into the aquatic environment. These compounds can exert an unknown effect on aquatic life and humans if the water is used for human consumption. Thus, unravelling their occurrence in the aquatic system is crucial for the well-being of life and monitoring purposes. To this end, we used nanoflow-liquid and ion-exchange chromatography hyphenated with orbitrap high-resolution tandem mass spectrometry to detect several thousands of features (chemical entities) in surface water. Later, the features were narrowed down to a few focused lists using a stepwise filtering strategy, for which the structural elucidation was made. Accordingly, the chemical structure was confirmed for 83 compounds from different application areas, mainly being pharmaceuticals, pesticides, and other multiple application industrial compounds and xenobiotic degradation products. The compounds with the highest concentration were lamotrigine (27.6 μg/L), valsartan (14.4 μg/L), and ibuprofen (12.7 μg/L). Some compounds such as prosulfocarb, fluopyram, and tris(3-chloropropyl) phosphate were found to be the most abundant and widespread contaminants. Of the 32 sampling sites, nearly half of the sites (47%) contained more than 30 different compounds. Two sampling sites were far more contaminated than other sites based on the estimated concentration and the number of identified contaminants they contained. Our triplicate analysis revealed a low relative standard deviation between replicates, advocating for the added value in analysing more sampling sites instead of sample repetition. Overall, our study elucidated the occurrence of organic contaminants from a variety of sources in the aquatic environment. Furthermore, our findings highlighted the role of suspected non-target screening in exposing a snapshot of the chemical composition of surface water and the localized possible contamination sources.

Recent Trends in Multiclass Analysis of Emerging Endocrine Disrupting Contaminants (EDCs) in Drinking Water

Ingestion of water is a major route of human exposure to environmental contaminants. There have been numerous studies exploring the different compounds present in drinking water, with recent attention drawn to a new class of emerging contaminants: endocrine-disrupting compounds (EDCs). EDCs encompass a broad range of physio-chemically diverse compounds; from naturally occurring to manmade. Environmentally, EDCs are found as mixtures containing multiple classes at trace amounts. Human exposure to EDCs, even at low concentrations, is known to lead to adverse health effects. Therefore, the ability to evaluate EDC contamination with a high degree of sensitivity and accuracy is of the utmost importance. This review includes (i) discussion on the perceived and actual risks associated with EDC exposure (ii) regulatory actions that look to limit EDC contamination (iii) analytical methods, including sample preparation, instrumentation and bioassays that have been advanced and employed for multiclass EDC identification and quantitation.

Effect-directed analysis of a hospital effluent sample using A-YES for the identification of endocrine disrupting compounds

An effect-directed analysis (EDA) approach was used to identify the compounds responsible for endocrine disruption in a hospital effluent (Basque Country). In order to facilitate the identification of the potentially toxic substances, a sample was collected using an automated onsite large volume solid phase extraction (LV-SPE) system. Then, it was fractionated with a two-step orthogonal chromatographic separation and tested for estrogenic effects with a recombinant yeast (A-YES) in-vitro bioassay. The fractionation method was optimized and validated for 184 compounds, and its application to the hospital effluent sample allowed reducing the number of unknowns from 292 in the raw sample to 35 after suspect analysis of the bioactive fractions. Among those, 7 of them were confirmed with chemical standards. In addition, target analysis of the raw sample confirmed the presence of mestranol, estrone and dodemorph in the fractions showing estrogenic activity. Predictive estrogenic activity modelling using quantitative structure-activity relationships indicated that the hormones mestranol (5840 ng/L) and estrone (128 ng/L), the plasticiser bisphenol A (9219 ng/L) and the preservative butylparaben (1224 ng/L) were the main contributors of the potential toxicity. Derived bioanalytical equivalents (BEQs) pointed mestranol and estrone as the main contributors (56 % and 43 %, respectively) of the 50 % of the sample's explained total estrogenic activity.

HRMS screening of organophosphate flame retardants and poly-/perfluorinated substances in dust from cars and trucks: Occurrence and human exposure implications

Time spent within vehicles' cabin has been largely increased during the last years. As a result, the assessment of indoor dust quality is meaningful since dust can be a source of numerous emerging contaminants associated with adverse effects in human health. To this end, fourteen cars and ten trucks from the city of Thessaloniki, Northern Greece were selected to assess the quality of vehicles' microenvironments. An HRMS-based strategy was deployed for the target and non-target analysis of the collected samples. The target approach aimed at the accurate mass screening of nine organophosphate flame retardants (OPFRs) and nine per-/polyfluorinated compounds (PFAS), revealing mean concentrations for the OPFRs varied from <MQL-3409 ng/g for tris(1,3-dichloro-2-propyl) phosphate (TDCP), while the PFASs were either not detected (<MDL) or detected below the quantification limit (<MQL). To exploit the advanced technology of HRMS, a non-target analysis (NTA) workflow was also designed and employed, allowing the identification of 17 non-targets (plasticizers, PPCPs, pesticides and industrial chemicals) at identification confidence levels from 3 to 1. The statistical analysis between the positive findings and vehicles' conditions evidenced a possible of association just for individual cases. Lastly, a preliminary evaluation of human exposure to the target analytes was applied with the view to assess the potential harmful effects. All values were < 1 indicating no special effects because of exposure to this concentration level.

Prioritization based on risk assessment to study the bioconcentration and biotransformation of pharmaceuticals in glass eels (Anguilla anguilla) from the Adour estuary (Basque Country, France)

The presence of contaminants of emerging concern in the aquatic environment directly impacts water-living organisms and can alter their living functions. These compounds are often metabolized and excreted, but they can also be accumulated and spread through the food chain. The metabolized contaminants can also lead to the formation of new compounds with unknown toxicity and bioaccumulation potential. In this work, we have studied the occurrence, bioconcentration, and biotransformation of CECs in glass eels (Anguilla anguilla) using UHPLC-HRMS. To select the target CECs, we first carried out an environmental risk assessment of the WWTP effluent that releases directly into the Adour estuary (Bayonne, Basque Country, France). The risk quotients of every detected contaminant were calculated and three ecotoxicologically relevant contaminants were chosen to perform the exposure experiment: propranolol, diazepam, and irbesartan. An experiment of 14 days consisting of 7 days of exposure and 7 days of depuration was carried out to measure the bioconcentration of the chosen compounds. The quantitative results of the concentrations in glass eel showed that diazepam and irbesartan reached BCF ≈10 on day 7, but both compounds were eliminated after 7 days of depuration. On the other hand, propranolol's concentration remains constant all along with the experiment, and its presence can be detected even in the non-exposed control group, which might suggest environmental contamination. Two additional suspect screening strategies were used to identify metabolization products of the target compounds and other xenobiotics already present in wild glass eels. Only one metabolite was identified, nordiazepam, a well-known diazepam metabolite, probably due to the low metabolic rate of glass eels at this stage. The xenobiotic screening confirmed the presence of more xenobiotics in wild glass eels, prominent among them, the pharmaceuticals exemestane, primidone, iloprost, and norethandrolone.

From target analysis to suspect and non-target screening of endocrine-disrupting compounds in human urine

In the present work, a target analysis method for simultaneously determining 24 diverse endocrine-disrupting compounds (EDCs) in urine (benzophenones, bisphenols, parabens, phthalates and antibacterials) was developed. The target analysis approach (including enzymatic hydrolysis, clean-up by solid-phase extraction and analysis by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS)) was optimized, validated and applied to volunteers’ samples, in which 67% of the target EDCs were quantified. For instance, benzophenone-3 (0.2–13 ng g⁻¹), bisphenol A (7.7–13.7 ng g⁻¹), methyl 3,5-dihydroxybenzoate (8–254 ng g⁻¹), mono butyl phthalate (2–17 ng g⁻¹) and triclosan (0.3–9 ng g⁻¹) were found at the highest concentrations, but the presence of other analogues was detected as well. The developed target method was further extended to suspect and non-target screening (SNTS) by means of LC coupled to high-resolution MS/MS. First, well-defined workflows for SNTS were validated by applying the previously developed method to an extended list of compounds (83), and then, to the same real urine samples. From a list of approximately 4000 suspects, 33 were annotated at levels from 1 to 3, with food additives/ingredients and personal care products being the most abundant ones. In the non-target approach, the search was limited to molecules containing S, Cl and/or Br atoms, annotating 4 pharmaceuticals. The results from this study showed that the combination of the lower limits of detection of MS/MS and the identification power of high-resolution MS/MS is still compulsory for a more accurate definition of human exposome in urine samples.

Screening of Contaminants of Emerging Concern in Surface Water and Wastewater Effluents, Assisted by the Persistency-Mobility-Toxicity Criteria

Contaminants of emerging concern (CECs) are compounds of diverse origins that have not been deeply studied in the past which are now accruing growing environmental interest. The NOR-Water project aimed to identify the main CECs and their sources in the water environment of Northern Portugal-Galicia (located in northwest Spain) transnational region. To achieve these goals, a suspect screening analytical methodology based on the use of liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) was applied to 29 sampling sites in two campaigns. These sampling sites included river and sea water, as well as treated wastewater. The screening was driven by a library of over 3500 compounds, which included 604 compounds prioritized from different relevant lists on the basis of the persistency, mobility, and toxicity criteria. Thus, a total of 343 chemicals could be tentatively identified in the analyzed samples. This list of 343 identified chemicals was submitted to the classification workflow used for prioritization and resulted in 153 chemicals tentatively classified as persistent, mobile, and toxic (PMT) and 23 as very persistent and very mobile (vMvP), pinpointing the relevance of these types of chemicals in the aqueous environment. Pharmaceuticals, such as the antidepressant venlafaxine or the antipsychotic sulpiride, and industrial chemicals, especially high production volume chemicals (HPVC) such as ε-caprolactam, were the groups of compounds that were detected at the highest frequencies.

Use of Passive and Grab Sampling and High-Resolution Mass Spectrometry for Non-Targeted Analysis of Emerging Contaminants and Their Semi-Quantification in Water

Different groups of organic micropollutants including pharmaceuticals and pesticides have emerged in the environment in the last years, resulting in a rise in environmental and human health risks. In order to face up and evaluate these risks, there is an increasing need to assess their occurrence in the environment. Therefore, many studies in the past couple of decades were focused on the improvements in organic micropollutants’ extraction efficiency from the different environmental matrices, as well as their mass spectrometry detection parameters and acquisition modes. This paper presents different sampling methodologies and high-resolution mass spectrometry-based non-target screening workflows for the identification of pharmaceuticals, pesticides, and their transformation products in different kinds of water (domestic wastewater and river water). Identification confidence was increased including retention time prediction in the workflow. The applied methodology, using a passive sampling technique, allowed for the identification of 85 and 47 contaminants in the wastewater effluent and river water, respectively. Finally, contaminants’ prioritization was performed through semi-quantification in grab samples as a fundamental step for monitoring schemes.

Drugs used during the COVID-19 first wave in Vitoria-Gasteiz (Spain) and their presence in the environment

The city of Vitoria-Gasteiz was one of the probable first entrances of the SARS-CoV2 in Spain, one of the worst affected countries in the world during the first COVID 19 wave. Driven by the urgency of the situation, multiple drugs with antiviral activity were used off label. Sadly, most of these treatments were of little or no benefit and thus, the number of patients suffering from COVID-19 attended in intensive care units (ICUs) multiplied. After being administered to patients, a variable proportion of these drugs reach the environment where they may have detrimental effects, although this aspect is usually ignored by healthcare professionals. In this study we measured the patterns of hospital drug use in the city of Vitoria-Gasteiz (Spain) during the first COVID-19 wave pandemic, focusing on those with antiviral activity and those used in the ICUs. Subsequently, we measured concentrations of selected drugs in the city's wastewater treatment plant influent and effluent and estimated the potential risk for the environment. The hospital use of certain antivirals and drugs used for sedo-analgesia were dramatically increased during the first wave (cisatracurium was multiplied by 25 and lopinavir/ritonavir by 20). A mean of 1.632 daily defined doses of hydroxychloroquine were used during the period of February-May 2020. In this study we report the first positive detection of hydroxychloroquine ever in the environment. We also show the second positive report of lopinavir. Low risk was estimated for hydroxychloroquine, lopinavir and ritonavir (Risk quotients (RQ) <1), and medium risk for azithromycin (RQ 0f 0.146).

Characterization of the contamination fingerprint of wastewater treatment plant effluents in the Henares River Basin (central Spain) based on target and suspect screening analysis

The interest in contaminants of emerging concern (CECs) has increased lately due to their continued emission and potential ecotoxicological hazards. Wastewater treatment plants (WWTPs) are generally not capable of eliminating them and are considered the main pathway for CECs to the aquatic environment. The number of CECs in WWTPs effluents is often so large that complementary approaches to the conventional target analysis need to be implemented. Within this context, multitarget quantitative analysis (162 compounds) and a suspect screening (>40,000 suspects) approaches were applied to characterize the CEC fingerprint in effluents of five WWTPs in the Henares River basin (central Spain) during two sampling campaigns (summer and autumn). The results indicated that 76% of the compounds quantified corresponded to pharmaceuticals, 21% to pesticides and 3% to industrial chemicals. Apart from the 82 compounds quantified, suspect screening increased the list to 297 annotated compounds. Significant differences in the CEC fingerprint were observed between summer and autumn campaigns and between the WWTPs, being those serving the city of Alcalá de Henares the ones with the largest number of compounds and concentrations. Finally, a risk prioritization approach was applied based on risk quotients (RQs) for algae, invertebrates, and fish. Azithromycin, diuron, chlortoluron, clarithromycin, sertraline and sulfamethoxazole were identified as having the largest risks to algae. As for invertebrates, the compounds having the largest RQs were carbendazim, fenoxycarb and eprosartan, and for fish acetaminophen, DEET, carbendazim, caffeine, fluconazole, and azithromycin. The two WWTPs showing higher calculated Risk Indexes had tertiary treatments, which points towards the need of increasing the removal efficiency in urban WWTPs. Furthermore, considering the complex mixtures emitted into the environment and the low dilution capacity of Mediterranean rivers, we recommend the development of detailed monitoring plans and stricter regulations to control the chemical burden created to freshwater ecosystems.

Xenobiotics-Division and Methods of Detection: A Review

Xenobiotics are compounds of synthetic origin, usually used for domestic, agricultural, and industrial purposes; in the environment, they are present in micropollutant concentrations and high concentrations (using ng/L to µg/L units). Xenobiotics can be categorized according to different criteria, including their nature, uses, physical state, and pathophysiological effects. Their impacts on humans and the environment are non-negligible. Prolonged exposure to even low concentrations may have toxic, mutagenic, or teratogenic effects. Wastewater treatment plants that are ineffective at minimizing the release of xenobiotic compounds are one of the main sources of xenobiotics in the environment (e.g., xenobiotic compounds reach the environment, affecting both humans and animals). In order to minimize the negative impacts, various laws and regulations have been adopted in the EU and across the globe, with an emphasis on xenobiotics removal from the environment, in a way that is economically, environmentally, and socially acceptable, and will not result in their accumulation, or creation of compounds that are more harmful. Detection methods allow detecting even small concentrations of xenobiotics in samples, but the problem is the diversity and mix of compounds present in the environment, in which it is not known what their effects are). In this review, the division of xenobiotics and their detection methods will be presented.