Potential Ecological and Human Health Risks Associated With the Presence of Pharmaceutically Active Compounds in the Aquatic Environment

A solar flow photo-reactor for antibiotic removal from aquaculture effluents using TiO2/carbon quantum dots

Effluents contaminated with antibiotics must be treated before reuse or even discharge into the aquatic environment, avoiding the increase of antimicrobial resistance (AMR) - a major public health problem of the 21st century. Little is known regarding the natural solar photodegradation of antibiotics in tubular reactors operated under flow mode and even less concerning the application of photocatalysts. The use of photocatalysts is considered a promising strategy for a sustainable solar-driven removal of antibiotics from effluents. In this work, the photodegradation of two antibiotics widely used in aquaculture, namely, sulfadiazine (SDZ) and oxolinic acid (OXA), was investigated under solar flow mode in the absence and presence of carbon quantum dots (CQDs) coupled with titanium dioxide (TiO2) (4% (w/w)). The obtained results showed that TiO2/CQDs (4% (w/w)) enhanced the photodegradation of both antibiotics, which is highly beneficial for their application in the treatment of aquaculture effluents. The accumulated UV energy needed for SDZ removal using the photocatalyst was less than 4 kJ L-1 in both simulated freshwater (phosphate buffer solution (PBS)) and simulated brackish water (sea salt solution (SSS)), while for OXA less than 5 kJ L-1 and around 15 kJ L-1 were needed for removal in PBS and in SSS, respectively. Moreover, results demonstrated that the proposed photocatalytic treatment was also efficient in the elimination of OXA and SDZ antibacterial activity, either in PBS or SSS. Therefore, photocatalysis under flow mode using TiO2/CQDs constitutes a promising and sustainable treatment for antibiotics' efficient removal from aquaculture effluents.

Enhanced purification of kitchen-oil wastewater driven synergistically by surface microelectric fields and microorganisms

The stable structure and toxic effect of refractory organic pollutants in wastewater lead to the problem of high energy consumption in water treatment technology. Herein, we propose a synergistic purification of refractory wastewater driven by microorganisms and surface microelectric fields (SMEF) over a dual-reaction-center (DRC) catalyst HCLL-S8-M prepared by an in situ growth method of carbon nitride on the Cu-Al₂O₃ surface. Characterization techniques demonstrate the successful construction of SMEF with strong electrostatic force over HCLL-S8-M based on cation-π interactions between metal copper ions and carbon nitride rings. With the catalyst as the core filler, an innovative fixed bed bioreactor is constructed to purify the actual kitchen-oil wastewater. The removal efficiency of the wastewater even with a very low biodegradability (BOD₅/COD = 0.33) can reach 60% after passing through this bioreactor. An innovative reaction mechanism is revealed for the first time that under the condition of a small amount of biodegradable organic matter, the SMEF induces the enrichment of electric active microorganisms (Desulfobulbus and Geobacter) in the wastewater, accelerates the interspecies electron transfer of intertrophic metabolism with the biodegradable bacteria through the extracellular electron transfer mechanism such as cytochrome C and self-secreted electron shuttle. The electrons of the refractory organic pollutants adsorbed on the surface of the catalyst are delocalized by the SMEF, which can be directly utilized by microorganisms through EPS conduction. The SMEF generated by electron polarization can maximize the utilization of pollutants and microorganisms in wastewater and further enhance degradation without adding any external energy, which is of great significance to the development of water self-purification technology.

The potential ecological risk of veterinary pharmaceuticals from swine wastewater on freshwater aquatic environment

The impact of pharmaceutical residue transport in the aquatic ecosystem has become an increasing subject of environmental interest due to the inherent bioactivity of trace levels of antibiotics and the negative environmental and public health impact. In this study, three veterinary pharmaceuticals including tetracycline, ivermectin, and salicylic acid were investigated in a piggery effluent from Western Cape, South Africa. Three freshwater organisms' taxonomic groups (Pseudokirchneriella subcapitata, Daphnia magna, and Tetrahymena thermophila) were used to determine the ecological risk of different treated piggery effluent concentration range of 1%, 10%, and 20% and a cocktail mixture of veterinary pharmaceuticals of environmental concerns. The average concentration of veterinary pharmaceuticals was in the range of 47.35, 7.19, and 1.46 μg L^-1 for salicylic acid, chloro-tetracycline, and ivermectin, respectively. P. subcapitata exposed to 20% piggery wastewater effluent at 24- and 48-h EC₅₀ showed a toxicity value of 14.2% and 13.6% (v/v), respectively. The study established the ecological risk of the test compounds as low to medium risk for low-level dose and low concentrations of piggery effluent. The relative sensitivity ranking of the taxa drawn is microalgae > protozoa > Cladocera. The study results demonstrated that a high dose of piggery effluent and mixtures of veterinary pharmaceutical can pose a high risk in freshwater ecosystems. PRACTITIONER POINTS: Transport processes of veterinary antibiotics into the environment were investigated. Dilution effect of the veterinary pharmaceutical on the antibiotic levels exists. High dose of piggery effluent presented an ecological risk.

Acute Toxicity of a Marine Emerging Pollutant (Promethazine Hydrochloride) on Artemia sp

Recently, there has been a worrying increase in the pollution of the aquatic ecosystem caused by emerging contaminants (ECs) detected in wastewater effluent discharges. Although traces of ECs in waters have been found in low concentrations, it leads to negative effects for nontarget organisms. Antihistamines are a class of drugs largely used, whose metabolites are widespread in the aquatic ecosystem. The aim of the study was to evaluate the short-term effects of promethazine hydrochloride on nauplii of Artemia sp. A high percentage of mortality and morphological alterations were found. The results suggest a possible correlation between exposure to antihistamine and an acceleration of larval development.

Pharmaceuticals as emerging pollutants: Case naproxen an overview

Nonsteroidal anti-inflammatory drugs (NSAIDs), including naproxen (NP), diclofenac, ibuprofen, etc., are widely used for fever and pain relief. NP is one of the most widely consumed drugs in the world, because it is available over the counter in many countries. Many studies have proven that NP is not eliminated in conventional water treatment processes and its biodegradation in the environment is also difficult compared to other drugs. Along these lines, we are aware that both the original compound and its metabolites can be found in different destinations in the environment. To assess the environmental exposure and the risks associated with NP, it is important to understand better the environment where they finally reach, the behavior of its original compounds, its metabolites, and its transformation products. In this sense, the purpose of this review is to summarize the current state of knowledge about the introduction and behavior of NP in the environments they reach and highlight research needs and gaps. Likewise, we present the sources, environmental destinations, toxicology, environmental effects, and quantification methodologies.

Nanohybrids-assisted photocatalytic removal of pharmaceutical pollutants to abate their toxicological effects - A review

Advancement in medication by health care sector has undoubtedly improved our life but at the same time increased the chemical burden on our natural ecosystem. The residuals of pharmaceutical products become part of wastewater streams by different sources such as excretion after their usage, inappropriate way of their disposal during production etc. Hence, they are serious health hazards for human, animal, and aquatic lives. Due to rapid urbanization, the increased demand for clean drinking water is a burning global issue. In this regard it is need of the present era to explore efficient materials which could act as photocatalyst for mitigation of pharmaceuticals in wastewater. Nanohybrid as photocatalyst is one of the widely explored class of materials in photocatalytic degradation of such harmful pollutants. Among these nanohybrids; metal based nanohybrids (metals/metal oxides) and carbon based nanohybrids (carbon nanotubes, graphene, fullerenes etc.) have been explored to remove pharmaceutical drugs. Keeping in view the increasing harmful impacts of pharmaceuticals; the sources of pharmaceuticals in wastewater, their health risk factors and their mitigation using efficient nanohybrids as photocatalysts have been discussed in this review.

Antibiotics, antibiotic-resistant bacteria, and resistance genes in aquaculture: risks, current concern, and future thinking

Aquaculture is remarkably one of the most promising industries among the food-producing industries in the world. Aquaculture production as well as fish consumption per capita have been dramatically increasing over the past two decades. Shifting of culture method from semi-intensive to intensive technique and applying of antibiotics to control the disease outbreak are the major factors for the increasing trend of aquaculture production. Antibiotics are usually present at subtherapeutic levels in the aquaculture environment, which increases the selective pressure to the resistant bacteria and stimulates resistant gene transfer in the aquatic environment. It is now widely documented that antibiotic resistance genes and resistant bacteria are transported from the aquatic environment to the terrestrial environment and may pose adverse effects on human and animal health. However, data related to antibiotic usage and bacterial resistance in aquaculture is very limited or even absent in major aquaculture-producing countries. In particular, residual levels of antibiotics in fish and shellfish are not well documented. Recently, some of the countries have already decided the maximum residue levels (MRLs) of antibiotics in fish muscle or skin; however, many antibiotics are yet not to be decided. Therefore, an urgent universal effort needs to be taken to monitor antibiotic concentration and resistant bacteria particularly multiple antibiotic-resistant bacteria and to assess the associated risks in aquaculture. Finally, we suggest to take an initiative to make a uniform antibiotic registration process, to establish the MRLs for fish/shrimp and to ensure the use of only aquaculture antibiotics in fish and shellfish farming globally.

Transformation Products of Emerging Pollutants Explored Using Non-Target Screening: Perspective in the Transformation Pathway and Toxicity Mechanism—A Review

The scientific community has increasingly focused on forming transformation products (TPs) from environmental organic pollutants. However, there is still a lot of discussion over how these TPs are generated and how harmful they are to living terrestrial or aquatic organisms. Potential transformation pathways, TP toxicity, and their mechanisms require more investigation. Non-target screening (NTS) via high-resolution mass spectrometry (HRMS) in model organisms to identify TPs and the formation mechanism on various organisms is the focus of this review. Furthermore, uptake, accumulation process, and potential toxicity with their detrimental consequences are summarized in various organisms. Finally, challenges and future research initiatives, such as performing NTS in a model organism, characterizing and quantifying TPs, and evaluating future toxicity studies on TPs, are also included in this review.

Transcriptomic response of HepG2 cells exposed to three common anti-inflammatory drugs: Ketoprofen, mefenamic acid, and diclofenac in domestic wastewater effluents

The biological impacts of residual pharmaceuticals in the complex wastewater effluents have not been fully understood. Here, we investigated changes in the transcriptomic responses of hepatobrastoma (HepG2) cells exposed to a single or partially combined three common non-steroidal anti-inflammatory drugs (NSAIDs); ketoprofen (KPF), mefenamic acid (MFA) and diclofenac (DCF), in domestic wastewater effluents. After 48 h sub-lethal exposure to single compounds, the DNA microarray analysis identified 57-184 differently expressed genes (DEGs). The hierarchical clustering analysis and GO enrichment of the DEGs showed that gene expression profiles of the NSAIDs were distinct from each other although they are classified into the same therapeutic category. Four maker genes (i.e., EGR1, AQP3, SQSTM1, and NAG1) were further selected from the common DEGs, and their expressions were quantified by qPCR assay in a dose-dependent manner (ranging from μg/L to mg/L). The results revealed the insignificant induction of the marker genes at 1 μg/L of KPF, MFA, and DCF, suggesting negligible biological impacts of the NSAIDs on gene expression (early cellular responses) of HepG2 at typical concentration levels found in the actual wastewater effluents. Based on the quantitative expression analysis of the selected marker genes, the present study indicated that the presence of wastewater effluent matrix may mitigate the potentially adverse cellular impacts of the NSAIDs.

Trends in microbial degradation and bioremediation of emerging contaminants

Modernization and modern ways of living demands more improved products from pharmaceuticals, cosmetics, and food processing industries. Moreover, industries like pesticides, fertilizers, dyeing, paints, detergent etc., also needs improvised products as per demand. As the new product emerges, the pollutants from these industries also constitute new type of danger to the environment and serious health risks to the living organisms. These emerging contaminants (ECs) are from different category of sources such as personal care products (PCPs), pharmaceuticals (Phcs), endocrine disrupting chemicals (EDCs), etc. These ECs can easily escape from the conventional water treatment and eventually get discharged in to the surface water and thus enters in to the ground water, soil, sediments, and also into the oceans. When these contaminants emerge we also require progress in tremendous process for preventing these hazardous chemicals by effective removal and treatment. For the past 50 years, both developed and developing countries are working on this treatment process and found that Microbial degradation and bioremediation are very useful for effective treatment to prevent their emissions. This treatment can be designed for any sort of ECs since the microbial members are so versatile to redesign their metabolic pathways when subject to exposure. However, implementing bioremediation is not alone efficient to degrade ECs and hence, combination of bioremediation, nanotechnology and physical treatment method will also provide sustainable, potent and fast degradation process. In this Book Chapter, we discuss in detail about the ECs, sources of microbial degradation process and its usefulness in the bioremediation of these ECs.

The link between pharmaceuticals and cyanobacteria: a review regarding ecotoxicological, ecological, and sanitary aspects

Cyanobacteria are important for ecosystem functioning, but eutrophication may affect the surrounding biome by losing ecosystem services and/or through affecting the cyanotoxins production that threatens ecological and human health. Pollution is an environmental issue that affects aquatic ecosystems worldwide, and the knowledge of the role of synthetic chemicals such as pharmaceuticals is still scarce. Therefore, studies coupling these two relevant issues are essential to better understand the ecological risks and the potential threats to public health. Thus, an overview of ecotoxicological tests performed in the literature exposing cyanobacteria to pharmaceuticals and the possible consequences regarding ecological and sanitary aspects was conducted. Moreover, a risk assessment was performed to enable a better understanding of pharmaceuticals affecting cyanobacteria ecology. Most of the studies found in the literature tested isolated pharmaceuticals in laboratory conditions, while others assessed mixture effects on in situ conditions. The endpoints most assessed were growth, photosynthesis, and antioxidant enzyme activity. The studies also point out that cyanobacteria may present resistance or sensitivity depending on the concentrations and the therapeutic class, which may cause a change in the ecosystem dynamics and/or sanitary implications due to cyanotoxin production. The risk assessment highlighted that antibiotics are among the most relevant substances due to the chemical diversity and higher levels found in the environment than other therapeutic classes. This review highlighted gaps regarding cyanotoxin release into aquatic environments due to the occurrence of pharmaceuticals and the need for more realistic experiments to better understand the potential consequences for human and environmental health.

Review of aquatic toxicity of pharmaceuticals and personal care products to algae

Pharmaceuticals and Personal Care Products (PPCPs) have been frequently detected in the environment around the world. Algae play a significant role in aquatic ecosystem, thus the influence on algae may affect the life of higher trophic organisms. This review provides a state-of-the-art overview of current research on the toxicity of PPCPs to algae. Nanoparticles, contained in personal care products, also have been considered as the ingredients of PPCPs. PPCPs could cause unexpected effects on algae and their communities. Chlorophyta and diatoms are more accessible and sensitive to PPCPs. Multiple algal endpoints should be considered to provide a complete evaluation on PPCPs toxicity. The toxicity of organic ingredients in PPCPs could be predicted through quantitative structure-activity relationship model, whereas the toxicity of nanoparticles could be predicted with limitations. Light irradiation can change the toxicity through affecting algae and PPCPs. pH and natural organic matter can affect the toxicity through changing the existence of PPCPs. For joint and tertiary toxicity, experiments could be conducted to reveal the toxic mechanism. For multiple compound mixture toxicity, concentration addition and independent addition models are preferred. However, there has no empirical models to study nanoparticle-contained mixture toxicity. Algae-based remediation is an emerging technology to prevent the release of PPCPs from water treatment plants. Although many individual algal species are identified for removing a few compounds from PPCPs, algal-bacterial photobioreactor is a preferable alternative, with higher chances for industrial applications.

Lack of Awareness of the Impact of Improperly Disposed Of Medications and Associated Factors: A Cross-Sectional Survey in Indonesian Households

Introduction: Disposal of unused medications through environmentally unsafe routes is common in Indonesia. The lack of awareness of the impact of improperly disposed of medications is a significant contributing factor. The objectives of this study were to identify factors associated with lack of awareness of the impact of improperly disposed of unused medications and to assess the associations of awareness with medication disposal practices among the general population in Indonesia.

Patients and methods: An observational cross-sectional survey was conducted using nonprobability sampling in Bandung, Indonesia, from November 2017 to January 2018 among respondents who were older than 18 years, had used any medication in the past, were literate, and had signed an informed consent document. Disposal practices and awareness regarding the impact of improperly disposed of unused medications were collected using an online- and a paper-based pre-validated questionnaire. The paper-based questionnaires were distributed to respondents in public places such as city center, markets, and religious places. Binary logistic regression was performed to assess associations of sociodemographic and other related factors with a lack of awareness. Odds ratios (ORs) with 95% confidence intervals (CIs) are reported.

Results: Of 497 participating respondents, 433 and 64 respondents filled an online- or a paper-based questionnaire, respectively. Most respondents were female, aged between 18 and 30 years, and students/university students. Of 497 respondents, more than half (53.1%) were not aware that improper medication disposal could harm the environment and population health. Most respondents (79.5%) had never received information about proper medication disposal practices. The education level, the number of stored medications at home, and previous education about medication disposal practices were significantly associated with awareness of proper practices. In the multivariate analysis, only those with previous education about medication disposal practices were less likely to report a lack of awareness (OR: 0.043; 95% CI: 0.02–0.09). Respondents with a lack of awareness tended to dispose of their unused medications in the garbage or shared them with friends or relatives.

Conclusion: There is a clear need to increase awareness of the importance of proper medication disposal practices, in particular among the student population of Bandung city, Indonesia. Healthcare providers can play an important role by educating this specific population on the proper disposal of unused medications.

α-γ-Type [Mo8O26]4--Containing Metal-Organic Complex Possessing Efficient Catalytic Activity toward the Oxidation of Thioether Derivatives

In this work, a new α-γ-type [Mo₈O₂₆]^4- anion was first synthesized and characterized by single-crystal X-ray diffraction analysis and was obtained by introducing molybdate to the synthesis of metal-organic complex (MOC) under hydrothermal conditions. An octamolybdate-based MOC, namely, {[Cu₈(H₂O)₆](dpyh)₄(α-γ-Mo₈O₂₆) }·(β-Mo₈O₂₆)·8.5H₂O (H₂dpyh = N,N-bis(3-pyrazolamide)-1,2-hexahydrobenzene), was obtained. The α-γ-type [Mo₈O₂₆]^4- anion was composed of four MoO₆ octahedra and four MoO₅ trigonal bipyramids by sharing their edges and corners. The title complex exhibited a 1D structure in which an α-γ-type [Mo₈O₂₆]^4- anion was connected with [Cu₄(dpyh)₂] units in a staggered manner. Under optimized conditions, complex 1 as the catalyst can achieve a highly efficient conversion (more than 99%) of thioanisole within 30 min and above 99% selectivity toward sulfoxide. Furthermore, efficient catalytic oxidation of thioether derivatives was also performed with 1 as the catalyst. In addition, the stable electrochemical sensing performance and adsorption capacity toward organic dyes were tested.

Removal of Drugs in Polluted Waters with Char Obtained by Pyrolysis of Hair Waste from the Tannery Process

The presence and final destination of pharmaceutical compounds in waters constitute one of the emerging events in current environmental chemistry. Two widely consumed compounds have been evaluated in this study, amoxicillin (AMOX) and diclofenac (DFC), at a concentration of 200 mg L-1. The presence of both in wastewater has been verified, generating problems in ecosystems and human health. Pyrolysis of hair waste from a tannery process was performed in a fixed-bed reactor. Char was obtained at different operating temperatures (300, 350, 400, and 450 °C), which underwent a characterization of heavy metals and elemental composition. An activation process was applied to the char obtained at 450 °C by means of physicochemical processes and with two chemical agents (KOH and K2CO3). For the removal of drugs, two separate tests were performed, one for 28 days and the other one for 4 h, to assess the efficiency and the percentage of removal. It was found that the char obtained at 450 °C is the one that removes most of both compounds: more than 90% of AMOX and more than 80% of DFC.

Present applications of titanium dioxide for the photocatalytic removal of pollutants from water: A review

The evolution of modern technology and industrial processes has been accompanied by an increase in the utilization of chemicals to derive new products. Water bodies are frequently contaminated by the presence of conventional pollutants such as dyes and heavy metals, as well as microorganisms that are responsible for various diseases. A sharp rise has also been observed in the presence of new compounds heretofore excluded from the design and evaluation of wastewater treatment processes, categorized as "emerging pollutants". While some are harmless, certain emerging pollutants possess the ability to cause debilitating effects on a wide spectrum of living organisms. Photocatalytic degradation has emerged as an increasingly popular solution to the problem of water pollution due to its effectiveness and versatility. The primary objective of this study is to thoroughly scrutinize recent applications of titanium dioxide and its modified forms as photocatalytic materials in the removal and control of several classes of water pollutants as reported in literature. Different structural modifications are used to enhance the performance of the photocatalyst such as doping and formation of composites. The principles of these modifications have been scrutinized and evaluated in this review in order to present their advantages and drawbacks. The mechanisms involved in the removal of different pollutants through photocatalysis performed by TiO2 have been highlighted. The factors affecting the mechanism of photocatalysis and those affecting the performance of different TiO2-based photocatalysts have also been thoroughly discussed, thereby presenting a comprehensive view of all aspects involved in the application of TiO₂ to remediate and control water pollution.

Surface Enhanced Raman Spectroscopy in environmental analysis, monitoring and assessment

Environmental pollution is usually monitored via mass spectrometry-based approaches. Such techniques are extremely sensitive but have several disadvantages. The instruments themselves are expensive, require specialized training to use and usually cannot be taken into the field. Samples also usually require extensive pre-treatment prior to analysis which can affect the final result. The development of analytical methods that matched the sensitively of mass spectrometry but that could be deployed in the field and require minimal sample processing would be highly advantageous for environmental monitoring. One method that may meet these criteria is Surface Enhanced Raman Spectroscopy (SERS). This is a surface-sensitive technique that enhances Raman scattering by molecules adsorbed on rough nanostructure surfaces such as gold or silver nanoparticles. SERS gives selective spectral enhancement such that increases in sensitivity of 10¹⁰ to 10¹⁴ have been reported. While this means SERS is, theoretically at least, capable of single molecule detection such a signal enhancement is hard to achieve in practice. In this review the background of SERS is introduced for the environmental scientist and the recent literature on the detection of several classes of environmental pollutants using this technique is discussed. For heavy metals the lowest limit of detection reported was 0.45 μg/L for Mercury; for pharmaceuticals, 2.4 μg/L for propranolol; for endocrine disruptors, 0.35 μg/L for 17β-estradiol; for perfluorinated compounds, 500 μg/L for perfluorooctanoic acid and for inorganic pollutants, 37g/L for general pesticide markers. The signal enhancements achieved in each case show great promise for the detection of pollutants at environmentally relevant concentrations and, although it does not yet routinely match the sensitivity of mass spectrometry. Further work to develop SERS methods and apply them for the detection of contaminants could be of wide benefit for environmental science.

Pharmaceuticals residues and xenobiotics contaminants: Occurrence, analytical techniques and sustainable alternatives for wastewater treatment

Emerging contaminants are increasingly present in the environment, and their appearance on both the environment and health of living beings are still poorly understood by society. Conventional sewage treatment facilities that are under validity and were designed years ago are not developed to remove pharmaceutical compounds, their main focus is organic and bacteriological removal. Pharmaceutical residues are associated directly with quantitative production aspects as well as inadequate waste management policies. Persistent classes of emerging compounds such as xenobiotics present molecules whose physicochemical properties such as small molecular size, ionizability, water solubility, lipophilicity, polarity and volatility make degradability, identification and quantification of these complex compounds difficult. Based on research results showing that there is a possibility of risk to human and environmental health the presence of these compounds in the environment this article aimed to review the main pharmaceutical and xenobiotic residues present in the environment, as well as to present the most common methodologies used. The most commonly used analytical methods for identifying these compounds were HPLC and Gas Chromatography coupled with mass spectrometry with potential for characterize complex substances in the environment with low concentrations. An alternative and low-cost technology for emerging compound treatment demonstrated in the literature with a satisfactory performance for several types of sewage such as domestic sewage, wastewater and agroindustrial, was the Wetlands Constructed. The study was able to identify the main compounds that are being found in the environment and identify the most used analytical methods to identify and quantify these compounds, bringing some alternatives combining technologies for the treatment of compounds. Environmental contamination is eminent, since the production of emerging compounds aims to increase along with technological development. This demonstrates the need to explore and aggregate sewage treatment technologies to reduce or prevent the deposition of these compounds into the environment.

Assessing the contribution of hydroxylation species in the photochemical transformation of primidone (pharmaceutical)

Pharmaceutical and personal care products (PPCPs) are a group of emerging contaminants that have frequently been detected in aqueous environments. Phototransformation driven by solar irradiation is one of the most important natural processes for the elimination of PPCPs. In this study, primidone (PMD) was chosen as a model "photorefractory" compound. A series of experiments were conducted to assess if reactive intermediates (RIs), such as hydroxyl radical (HO), singlet oxygen (¹O₂), and triplet states of dissolved organic matter (³DOM^⁎), inhibited or enhanced the photochemical transformation of PMD under simulated solar irradiation. The results indicate that HO plays a key role in the photodegradation of PMD and that dissolved oxygen can affect the degradation rate of PMD by promoting HO formation. Our results demonstrated that PMD can not only react with free HO (HO_-free) but also react with lower-energy hydroxylation agents (HO_-like). The contributions of HO_-free and HO_-like to PMD degradation in various dissolved organic matter (DOM) solutions were estimated by a methane-quenching experiment. The results indicated that the HO_-like species were important in the photodegradation of "photorefractory" compounds. The bimolecular reaction rate constant of the reaction of free HO with PMD was measured as (5.21 ± 0.02) × 10⁹ M^-1 s^-1 by using electron pulse radiolysis. Furthermore, PMD was used as a probe to estimate the steady-state concentration of HO_-free in various DOM solutions. Using the multivariate statistical strategies of orthogonal projection to latent structures discriminant analysis (OPLS-DA) and hierarchical clustering, 28 photochemical transformation products (TPs) of PMD were successfully identified from the DOM matrix.

Fate, occurrence and potential adverse effects of antimicrobials used for treatment of tuberculosis in the aquatic environment in South Africa

The consumption of tonnes of anti-tubercular and other anti-microbial compounds for the control of the tuberculosis epidemic and other opportunistic diseases associated with human immunodeficiency virus presents tuberculosis-endemic countries such as South Africa, with a problem regarding the occurrence and fate of these compounds in the aquatic environment. The majority of these compounds are not readily degradable and could persist in the aquatic environment with potential detrimental effect on the aquatic microbiota ecosystem, development and dissemination of anti-microbial resistance as well as chronic toxicity in humans due to long-term exposure. This review summarises and discusses the occurrence, fate and potential adverse effects of the commonly administered anti-tubercular compounds in the aquatic environment in tuberculosis-endemic countries and South Africa in particular. It further attempts to identify information gaps in the literature regarding anti-tubercular compounds in the environment that needs further investigation so that their risk can be comprehensively assessed and impact mitigated.

Sorption and leaching behavior of bithionol and levamisole in soils

The batch experiments were conducted to understand sorption process of bithionol (BIT) in yellow soil (YS) and red soil (RS), while column leaching experiments were performed to evaluate the leaching behavior of BIT and levamisole (LEV) in the tested soils. The adsorption and desorption data fitted well with the Freundlich isotherms (R² ≥ 0.94). The distribution coefficient of BIT in the YS and RS were 104 and 98.3 L/kg, respectively. Hysteresis was observed for bithionol desorption in the YS and RS, with hysteresis coefficient of 0.917 and 0.928, respectively. Dissolved organic matter (DOM) addition and acid condition enhanced the adsorption of BIT in the soil. Both BIT and LEV showed poor leaching potential in the tested soils. More than 80% of BIT and LEV remained in the surface soil layer and the amount of the two target compounds in the leachates accounted for less than 1% of overall recovery. DOM showed little influence on the concentration of BIT and LEV in the leachates collected at different time. The results could fill the gap on the behavior of BIT and LEV in soil under laboratory conditions.

Integrated Assessment of Wastewater Reuse, Exposure Risk, and Fish Endocrine Disruption in the Shenandoah River Watershed

Reuse of municipal and industrial wastewater treatment plant (WWTP) effluent is used to augment freshwater supplies globally. The Shenandoah River Watershed (U.S.A.) was selected to conduct on-site exposure experiments to assess endocrine disrupting characteristics of different source waters. This investigation integrates WWTP wastewater reuse modeling, hydrological and chemical characterization, and in vivo endocrine disruption bioassessment to assess contaminant sources, exposure pathways, and biological effects. The percentage of accumulated WWTP effluent in each river reach (ACCWW%) was used to predict environmental concentrations for consumer product chemicals (boron), pharmaceutical compounds (carbamazepine), and steroidal estrogens (estrone, 17-β-estradiol, estriol, and 17-α-ethinylestradiol). Fish endocrine disruption was evaluated using vitellogenin induction in adult male or larval fathead minnows. Water samples were analyzed for >500 inorganic and organic constituents to characterize the complex contaminant mixtures. Municipal ACCWW% at drinking water treatment plant surface water intakes ranged from <0.01 to 2.0% under mean-annual streamflow and up to 4.5% under mean-August streamflow. Measured and predicted environmental concentrations resulted in 17-β-estradiol equivalency quotients ranging from 0.002 to 5.0 ng L^-1 indicating low-to-moderate risk of fish endocrine disruption. Results from the fish exposure experiments showed low (0.5- to 3.2-fold) vitellogenin induction in adult males.

Varying the exposure period and duration of neuroactive pharmaceuticals and their metabolites modulates effects on the visual motor response in zebrafish (Danio rerio) larvae

Pharmaceuticals and personal care products are emerging contaminants that are increasingly detected in surface waters around the world. Despite the rise in environmental detections, measured concentrations are still typically low, raising the importance of environmental risk assessments that focus on ecologically relevant sublethal endpoints, such as altered behavior. Neuroactive pharmaceuticals, like mental health medications, pain killers, etc., may be particularly potent in this regard as they are specifically designed to cause behavioral changes without causing physiologic impairment in mammalian systems. We screened 15 different popular neuroactive pharmaceuticals, ranging from antidepressants (including 3 major antidepressant metabolites), anxiety medications, and pain killers, under three different exposure scenarios (repeated, late acute and early transient exposure) to look for behavioral effects in larval zebrafish using the visual motor response (VMR). Drugs were screened at 0, 1, 10, and 100 μg/L in the repeated exposure scenario, and at 0 and 100 μg/L in the late acute and early transient exposure scenarios. Eight of the 15 compounds tested, specifically the antidepressants amitriptyline, fluoxetine, nor-fluoxetine, paroxetine, sertraline, nor-sertraline, venlafaxine, and the antipsychotic drug haloperidol decreased swimming activity by 25% to 40% under repeated exposure conditions. Five of the compounds (amitriptyline, fluoxetine, nor-fluoxetine, paroxetine, and sertraline) also significantly decreased activity by 17% to 31% in the late acute exposure paradigm. Three compounds (fluoxetine, paroxetine and venlafaxine) significantly altered swimming activity with early transient exposure, however creating a hyperactive response and increasing activity from 24% to 28%, while haloperidol significantly decreased activity by 31%. This paper is, to our knowledge, the first to screen so many neuroactive pharmaceuticals, including major metabolites, in parallel under multiple exposure conditions. We show that antidepressants most consistently alter VMR swimming activity. Additionally, we show that major antidepressant metabolites can potentially alter behavior as much as their parent compounds. Furthermore, we show that the magnitude and direction of behavioral effect is dependent on the exposure duration and period, indicating that a more diverse experimental approach might be needed to more accurately assess the risk these compounds pose to the environment.

Dietary yeast culture modulates immune response related to TLR2-MyD88-NF-kβ signaling pathway, antioxidant capability and disease resistance against Aeromonas hydrophila for Ussuri catfish (Pseudobagrus ussuriensis)

The aim of the present study was to investigate effects of dietary yeast culture on immune response related to TLR2-MyD88-NF-kβ signaling pathway, antioxidant capability and disease resistance against Aeromonas hydrophila for Ussuri catfish (Pseudobagrus ussuriensis). A total of 240 Ussuri catfish (mean weight of 7.39 ± 0.32 g) were randomly distributed into four groups that fed diets containing 0 (Y0), 10 (Y1), 20 (Y2) and 30 (Y3) g kg^-1 yeast culture for 8 weeks. The results indicated that dietary 10 g kg^-1 yeast culture supplementation significantly down-regulated mRNA levels of TLR2, MyD88, NF-kβ p65, IL-1β and IL-8 in the liver tissue compared with the control group (P < 0.05). Simultaneously, serum lysozyme (LZM) activity, respiratory burst activity (RBA) of phagocytes, plasma alkaline phosphatase (AKP) activity and immunoglobulin M (IgM) content were significantly improved in fish fed Y1 diet (P < 0.05). Fish fed Y1 diet had significantly higher serum alternative complement pathway activity (ACH50) and plasma complement 3 (C3) content than the Y3 group (P < 0.05). However, no significant differences were observed in plasma acid phosphatase (ACP) activity and complement 4 (C4) content among the groups (P > 0.05). Fish cumulative mortality rate (CMR) in the Y1 and Y2 groups were significantly lower than that in Y0 and Y3 groups (P < 0.05), and the lowest CMR was observed in the Y1 group after challenge by A. hydrophila. The highest hepatic superoxide dismutase and glutathione peroxidase activities, total antioxidant capacity and the lowest malondialdehyde content were found in Y1 group, but no significant difference was found in hepatic catalase activity among the groups (P > 0.05). These results demonstrate that dietary 10 g kg^-1 yeast culture could effectively improve the immunity, antioxidant capability and disease resistance against A. hydrophila for Ussuri catfish and could down-regulate the mRNA expression levels of pro-inflammatory cytokines modulated by TLR2-MyD88-NF-kβ signaling pathway.

Extraction of clarithromycin and atenolol by cuttlefish bone powder

Pharmaceutical products including analgesics, antibiotics, and antiepileptics are often present in wastewater treatment effluents, lakes, and rivers and have been found in waterways of many countries. The adsorption of two common pharmaceuticals present in surface waters, clarithromycin (CLR) and atenolol (ATN), onto cuttlefish bone powder treated with HCl has been investigated. Adsorption experiments were carried out at different pH conditions and the experimental equilibrium data were fitted to the Langmuir and Freundlich. For the same experimental conditions (pH = 7), the estimated adsorption capacities are from 34.5 mg g^-1 for CLR and 39.5 mg g^-1 for ATN. The influence of adsorption pH was established for each compound. The negative values of ΔG at different temperatures for all samples indicate the spontaneous nature of the sorption process.

Presence of antibiotic residues in various environmental compartments of Shandong province in eastern China: Its potential for resistance development and ecological and human risk

OBJECTIVES

To investigate the occurrence of antibiotic residues in different types of environmental samples including water samples in rural Shandong province, China. Further, to characterize the potential ecological risk for development of antibiotic resistance in the environment, and the potential direct human health risk of exposure to antibiotics via drinking water and vegetables.

METHODS

Environmental samples (n = 214) (river water, waste water, drinking water, sediments, manure, soil and edible parts of vegetables) were collected in twelve villages in Shandong province in eastern China. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to determine the concentration of antibiotic residues. The ratio of the measured environmental concentrations (MEC) to the predicted no-effect concentrations (PNEC) was used to evaluate the ecological risk (risk quotient, RQ) for development of antibiotic resistance. The potential risks to human health through exposure to antibiotics in drinking water were assessed by comparing measured environmental concentrations (MEC) and predicted no-effect concentration in drinking water (PNEC_DW), and in vegetables by comparing estimated daily intake (EDI) to ADI.

RESULTS

Sulfapyridine, sulfamethoxazole, ciprofloxacin, enrofloxacin, levofloxacin, norfloxacin, chloramphenicol, florfenicol, doxycycline, and metronidazole were detected at concentrations ranging between 0.3 and 3.9 ng/L in river water, 1.3 and 12.5 ng/L in waste water, 0.5 and 21.4 ng/L in drinking water, 0.31 and 1.21 μg/kg in river sediment, 0.82 and 1.91 μg/kg in pig manure, 0.1 and 11.68 μg/kg in outlet sediment, 0.5 and 2.5 μg/kg in soil, and 6.3 and 27.2 μg/kg in vegetables. The RQs for resistance development were >1 for enrofloxacin, levofloxacin, and ranged between 0.1 and 1 for ciprofloxacin. MECs/PNEC_DW ratios were <1 from exposure to antibiotics through drinking water for both adults and children. EDI/ADI ratios were <0.1 from exposure to antibiotics by vegetable consumption.

CONCLUSIONS

Antibiotic pollutants were ubiquitous in various environmental compartments of Shandong province of China. Risk estimates indicated a potential for the measured levels of enrofloxacin, levofloxacin and ciprofloxacin in waste water to pose an ecological risk for resistance selection, and further studies are needed to validate this finding. The investigated antibiotics did not appear to pose an appreciable direct human health risk from environmental exposure through drinking water or vegetables consumption. However, they might still pose a risk for resistance development.

Occurrence and fate of emerging contaminants in municipal wastewater treatment plants from different geographical regions-a review

Emerging contaminants, such as antibiotics, pharmaceuticals, personal care products, hormones, and artificial sweeteners, are recognized as new classes of water contaminants due to their proven or potential adverse effects on aquatic ecosystems and human health. This review provides comprehensive data on the occurrence of 60 emerging contaminants (ECs) in influent, treated effluent, sludge, and biosolids in wastewater treatment plants (WWTPs). In particular, data on the occurrence of ECs in the influents and effluents of WWTPs are systematically summarized and categorized according to geographical regions (Asia, Europe, and North America). The occurrence patterns of ECs in raw influent and treated effluents of WWTPs between geographical regions were compared and evaluated. Concentrations of most ECs in raw influent in Asian region tend to be higher than those in European and North American countries. Many antibiotics were detected in the influents and effluents of WWTPs at concentrations close to or exceeding the predicted no-effect concentrations (PNECs) for resistance selection. The efficacy of EC removal by sorption and biodegradation during wastewater treatment processes are discussed in light of kinetics and parameters, such as sorption coefficients (K_d) and biodegradation constants (k_biol), and physicochemical properties (i.e. log K_ow and pK_a). Commonly used sampling and monitoring strategies are critically reviewed. Analytical research needs are identified, and novel investigative approaches for future monitoring studies are proposed.

Organic contaminants in African aquatic systems: Current knowledge, health risks, and future research directions

Organic contaminants (OCs) are increasingly being reported in African aquatic systems, yet a critical evaluation of the literature is still lacking. The objectives of this review were to: (1) identify hotspot reservoirs, transfer pathways and ecological and human risks of OCs, (2) identify potential interventions to minimize the health risks, and (3) highlight knowledge gaps and research constraints. OCs widely reported in aquatic systems include pesticides, pharmaceuticals, plasticizers, solvents, endocrine disrupting compounds, and antimicrobial resistance genes, originating from applications in crop protection, veterinary and animal husbandry, human sanitation and hygiene, human vector and disease control. Potential hotspot reservoirs of OCs include wastewaters, on-site sanitation systems, leachates from non-engineered landfills and contaminated recharge of shallow groundwater systems. OCs could be transferred into humans via drinking of contaminated water, consumption of contaminated crops and aquatic foods, and to a lesser extent, inhalation and dermal contact. Ecological effects including intersex, estrogenicity, and acute and chronic toxicity occur in avian and aquatic species. Although the evidence base of human ecotoxicological effects of OC remains weak, pesticides have been reported in human milk, serum and sperms, pointing to potential chronic and acute toxicity and endocrine disruption. The prevalence of antimicrobials and their resistance genes could in turn lead to antimicrobial resistance in humans. The lack of OC monitoring in drinking water, coupled with over-reliance on untreated drinking water vulnerable to OC contamination predisposes humans to OC health risks. Appropriate water treatment methods, were identified, and a conceptual framework developed to minimize the ecological and human health risks. Future research directions on OC hotspot reservoirs, environmental behaviour and fate, ecotoxicology, epidemiology and interventions to minimize health risks are highlighted. However, lack of advanced analytical facilities in most African countries and other developing regions will continue to constrain OC research for now and in the foreseeable future.

Sorption of albendazole in sediments and soils: Isotherms and kinetics

Albendazole is a broad-spectrum anthelmintic drug effective against gastrointestinal parasites in humans and animals. Despite the fact that it has been detected in environment (water, sediment and soil), there is no information on its fate in the environment. So, in order to understand the sorption process of albendazole in environment, the sorption mechanism and kinetic properties were investigated through sorption equilibrium and sorption rate experiments. For that purpose, batch sorption of albendazole on five sediment samples and five soil samples from Croatia's region with different physico-chemical properties was investigated. Except physico-chemical properties of used environmental solid samples, the effects of various parameters such as contact time, initial concentration, ionic strength and pH on the albendazole sorption were studied. The K_d parameter from linear sorption model was determined by linear regression analysis, while the Freundlich and Langmuir sorption models were applied to describe the equilibrium isotherms. The estimated K_d values varied from 29.438 to 104.43 mLg^-1 at 0.01 M CaCl₂ and for natural pH value of albendazole solution (pH 6.6). Experimental data showed that the best agreement was obtained with the linear model (R² > 0.99), while the rate of albendazole sorption is the best described with the kinetic model of pseudo-second-order. Obtained results point to a medium or even strong sorption of albendazole for soil or sediment particles, which is particularly dependent on the proportion of organic matter, pH, copper and zinc in them.

Removal of pharmaceuticals and personal care products by ammonia oxidizing bacteria acclimated in a membrane bioreactor: Contributions of cometabolism and endogenous respiration

We carried out batch experiments using biomass from a membrane bioreactor (MBR) to study the influence of ammonia oxidizing bacteria (AOB) on the removal of 45 pharmaceuticals and personal care products (PPCPs). Kinetic parameters such as biodegradation constants and adsorption coefficients with and without AOB inhibition were estimated. No significant differences in adsorption tendency were found, but the biodegradability of most compounds was enhanced when ammonia was completely oxidized, indicating that AOB present in MBR played a critical role in eliminating the PPCPs. Moreover, target PPCPs were degraded in 2 stages, first by cometabolic degradation related to AOB growth, and then by endogenous respiration by microorganisms in the absence of other growth substrate. The compounds were classified into 3 groups according to removal performance and cometabolic degradation. Our approach provides new insight into the removal of PPCPs via cometabolism and endogenous respiration under AOB enrichment cultures developed in MBR.

Immune responses to methanolic extract of black cumin (Nigella sativa) in rainbow trout (Oncorhynchus mykiss)

The immune stimulating effects of the methanolic extract of black cumin (Nigella sativa) in rainbow trout (Oncorhynchus mykiss) was evaluated. Variable concentrations of black cumin methanolic extract [0 (Control), 0.1 and 0.5 g kg^-1 of feed] were individually added to the basal diet and rainbow trout was fed for 30 days to assess the innate immune responses and growth performance. Feed conversion ratio significantly decreased in the group fed with 0.5 g kg^-1 black cumin extract. Respiratory burst activity was observed to be the highest in the 0.5 g kg^-1 black cumin extract fed group. Lysozyme and myeloperoxidase activities were significantly increased in fish of experimental groups compared to control (P < 0.05). TGF-β gene expression increased in black cumin 0.5 g kg^-1 treated group. IL-1β and TGF-β gene expressions decreased in black cumin 0.1 g kg^-1 administered group. Expression of IL-12 gene diminished in both the experimental groups. There was no significant difference in survival rates between black cumin extract treated fish groups and control (P > 0.05) after challenged with Aeromonas hydrophila. The results indicate that the methanolic extract of black cumin is a stimulator of some innate humoral immune responses, but it is ineffective for cytokine-related gene trancriptions in rainbow trout.

Electrochemical aptasensors for contaminants detection in food and environment: Recent advances

The growing number of contaminants requires the development of new analytical tools to meet the increasing demand for legislative actions on food safety and environmental pollution control. In this context, electrochemical aptamer-based sensors appear promising among all biosensors because they permit multiplexed analysis and provide fast response, sensitivity, specificity and low cost. The aim of this review is to give the readers an overview of recent important achievements in the development of electrochemical aptamer-based biosensors for contaminant detection over the last two years. Special emphasis is placed on aptasensors based on screen-printed electrodes which show a substantial improvement of analytical performances.

Removal characteristics of pharmaceuticals and personal care products: Comparison between membrane bioreactor and various biological treatment processes

We investigated the concentrations of 57 target compounds in the different treatment units of various biological treatment processes in South Korea, including modified biological nutrient removal (BNR), anaerobic-anoxic-aerobic (A2O), and membrane bioreactor (MBR) systems, to elucidate the occurrence and removal fates of PPCPs in WWTPs. Biological treatment processes appeared to be most effective in eliminating most PPCPs, whereas some PPCPs were additionally removed by post-treatment. With the exception of the MBR process, the A2O system was effective for PPCPs removal. As a result, removal mechanisms were evaluated by calculating the mass balances in A2O and a lab-scale MBR process. The comparative study demonstrated that biodegradation was largely responsible for the improved removal performance found in lab-scale MBR (e.g., in removing bezafibrate, ketoprofen, and atenolol). Triclocarban, ciprofloxacin, levofloxacin and tetracycline were adsorbed in large amounts to MBR sludge. Increased biodegradability was also observed in lab-scale MBR, despite the highly adsorbable characteristics. The enhanced biodegradation potential seen in the MBR process thus likely plays a key role in eliminating highly adsorbable compounds as well as non-degradable or persistent PPCPs in other biological treatment processes.

Evaluation of the short-term fate and transport of chemicals of emerging concern during soil-aquifer treatment using select transformation products as intrinsic redox-sensitive tracers

In this study, known products from oxic transformation of the X-ray contrast medium iopromide were introduced for the first time as intrinsic tracer for in situ characterization of the transition zone between oxic and suboxic conditions during the initial phase of soil-aquifer treatment (SAT). Two wet-dry cycles of a full-scale infiltration basin were monitored to characterize hydraulic retention times, redox conditions, removal of bulk organic parameters and the fate of chemicals of emerging concern (CECs). Tracer tests at the site showed an average hydraulic retention time of <20h before collection in drainage pipes located approximately 1.5m below surface. Dissolved oxygen at different depth rapidly depleted and only increased towards the end of the flooding event. Transformation of iopromide and all known intermediates to persistent transformation products (TPs) usually occurring during oxic biodegradation was very limited in samples from suction cups immediately underneath the basin. But transformation was complete in samples collected from the drainage outlet indicating that dissolved oxygen had been introduced to the system before sample collection in the combined drainage outlet. Similar to iopromide and its TPs, removal of several CECs (diclofenac, bezafibrate, mecoprop, TCEP) was inefficient after 90cm infiltration (<35%) but significantly enhanced in the combined drainage outlet (>80%). These results highlight that the analysis of iopromide along with its intermediates and persistent TPs can serve as a promising probing tool to determine overall efficiency of CEC biodegradation and to identify potential in situ oxygen limitations.

Modeling the biotransformation of trimethoprim in biological nutrient removal system

A pilot scale biological nutrient removal (BNR) process, batch experiments and modeling exercises were employed to investigate the removal and biotransformation of trimethoprim (TMP) in a BNR activated sludge process. The concentrations of the active microbial groups - ammonia oxidizing bacteria (AOB), ordinary heterotrophic organisms (OHOs) and polyphosphate accumulating organisms (PAOs) - in the BNR bioreactor were quantified through modeling of the pilot bioreactor. The overall TMP removal efficiency for the pilot BNR process was 64 ± 14% while the TMP biotransformation efficiencies in the anaerobic, anoxic and aerobic zones were 22 ± 20%, 27 ± 8% and 36 ± 5% respectively. Batch tests with and without nitrification inhibition showed that AOB played a role in the biotransformation of TMP in BNR activated sludge. A pseudo first order model which incorporated the contributions of PAOs, OHOs and AOB to the overall biodegradation of TMP was found to describe the biodegradation of TMP in batch tests with and without nitrification inhibition. This model showed that PAOs, OHOs and AOB contributed towards the biotransformation of TMP in aerobic BNR activated sludge with the biotransformation rate constants following the trend of k_AOB > k_OHOs > k_PAOs.

Multi-residue method for the determination of antibiotics and some of their metabolites in seafood

The presence of antibiotics in seafood for human consumption may pose a risk for consumers. A methodology for the analysis of antibiotics in seafood based on QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction, followed by detection and quantification using liquid chromatography coupled to mass spectrometry was developed. The analytical method was evaluated for the determination of 23 antibiotics (including parent compounds and some metabolites) in fish, mussels and clams. Recoveries ranged between 30% and 70% for most of the compounds and method detection and quantification limits (MDLs and MQLs) were between 0.01 and 0.31 ng/g dry weigh (dw) and 0.02-1.03 ng/g (dw) respectively. Real seafood samples were analysed using this method. Nine antibiotics were found at levels above MDLs; however none of them exceed the maximum residue limits (MRL) established by the authorities. Tetracycline was the most ubiquitous compound, presenting also the highest concentration: 5.63 ng/g (dw) in fish from Netherlands. In addition, an alternative technique based on microbial growth inhibition was explored as semiquantitative detection method of antibiotics in seafood. This methodology could be applied as a fast screening technique for the detection of macrolides and β-lactams in seafood but further research is needed for other antibiotics families.

Effects of pharmaceuticals and personal care products on marine organisms: from single-species studies to an ecosystem-based approach

Pharmaceuticals and personal care products (PPCPs) are contaminants of emerging concern that are increasing in use and have demonstrated negative effects on aquatic organisms. There is a growing body of literature reporting the effects of PPCPs on freshwater organisms, but studies on the effects of PPCPs to marine and estuarine organisms are limited. Among effect studies, the vast majority examines subcellular or cellular effects, with far fewer studies examining organismal- and community-level effects. We reviewed the current published literature on marine and estuarine algae, invertebrates, fish, and mammals exposed to PPCPs, in order to expand upon current reviews. This paper builds on previous reviews of PPCP contamination in marine environments, filling prior literature gaps and adding consideration of ecosystem function and level of knowledge across marine habitat types. Finally, we reviewed and compiled data gaps suggested by current researchers and reviewers and propose a multi-level model to expand the focus of current PPCP research beyond laboratory studies. This model includes examination of direct ecological effects including food web and disease dynamics, biodiversity, community composition, and other ecosystem-level indicators of contaminant-driven change.

Effects of erythromycin, trimethoprim and clindamycin on attached microbial communities from an effluent dominated prairie stream

In this study, differing metrics were utilized to measure effects of erythromycin (ER), trimethoprim (TR) and clindamycin (CL) on the structure and function of attached Wascana Creek, SK microbial communities. All three test antibiotics, especially ER, affected community structure and function of biofilms grown in rotating annular reactors. Biofilm thickness, bacterial biomass, and lectin binding biovolume (exopolymeric substances) were consistently less in ER treated biofilms when compared to the control. As well negative effects on protozoan numbers, and carbon utilization were detected. Finally, PCA analyses of DGGE results indicated that bacterial community diversity in ER exposed biofilms was always different from the control. ER exhibited toxic effects even at lower concentrations. Observations on TR and CL exposed biofilms indicated that bacterial biomass, lectin binding biovolume and carbon utilization were negatively affected as well. In terms of bacterial community diversity, however, CL exposed biofilms tended to group with the control while TR grouped with nutrient additions suggesting both nutritive and toxic effects. This study results represent an important step in understanding antibiotic effects, especially ER, on aquatic microbial communities. And because ER is so ubiquitous in receiving water bodies worldwide, the Wascana study results suggest the possibility of ecosystem disturbance elsewhere.

CAPSULE ABSTRACT

Erythromycin (ER) is ubiquitous in waterbodies receiving sewage effluent. Structure and function of microbial communities from an effluent dominated stream were negatively affected by ER, at realistic concentrations.

Performance and mechanisms for the removal of phthalates and pharmaceuticals from aqueous solution by graphene-containing ceramic composite tubular membrane coupled with the simultaneous electrocoagulation and electrofiltration process

In this study, commonly detected emerging contaminants (ECs) in water, including di-n-butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEHP), cephalexin (CLX), sulfamethoxazole (SMX) and caffeine (CAF), were selected as the target contaminants. A lab-prepared graphene-containing ceramic composite tubular membrane (TGCCM) coupled with the simultaneous electrocoagulation and electrofiltration process (EC/EF) in crossflow filtration mode was used to remove target contaminants in model solution. Meanwhile, a comparison of the removal efficiency was made among various tubular composite membranes reported, including carbon fibers/carbon/alumina composite tubular membrane (TCCACM), titania/alumina composite tubular membrane (TTACM) and alumina tubular membrane (TAM). The results of this study showed that the removal efficiencies for DnBP and DEHP were 99%, whereas 32-97% for cephalexin (CLX), sulfamethoxazole (SMX) and caffeine (CAF). In this work the mechanisms involved in removing target ECs were proposed and their roles in removing various ECs were also discussed. Further, two actual municipal wastewaters were treated to evaluate the applicability of the aforementioned treatment technology (i.e., TGCCM coupled with EC/EF) to various aqueous solutions in the real world.

Development and comparison of four methods for the extraction of antibiotics from a vegetative matrix

Studies have shown the potential for antibiotic uptake into food crops from irrigation water and soils containing pharmaceuticals. The objective of the present study was to develop and compare methods quantifying uptake of antibiotics in food crops. Four methods were evaluated: freeze-and-thaw cell lysing, mechanical maceration, tissue sonication, and microwave-assisted solvent extraction. Four antibiotics (ciprofloxacin, lincomycin, oxytetracycline, and sulfamethoxazole) were tested representing 4 classes of antibiotics. The methods were evaluated based on method detection limits, analyte recoveries, and sample preparation time. The 2 most viable methods, freeze-and-thaw lysing and mechanical maceration, were used on replicate lettuce (Lactuca sativa) samples grown using irrigation water spiked with 3 of the antibiotic contaminants. Only lincomycin and sulfamethoxazole were detected in lettuce samples at concentrations as high as 1757 ng/g and 425 ng/g, with detection limits of 57 ng/g and 35 ng/g, respectively. Freeze-and-thaw cell lysing provided the highest level of extraction efficiency on environmental samples and required the least amount of sample preparation while providing adequate detection limits and reproducible analyte recovery.

Metabolomics reveals the physiological response of Pseudomonas putida KT2440 (UWC1) after pharmaceutical exposure

Human pharmaceuticals have been detected in wastewater treatment plants, rivers, and estuaries throughout Europe and the United States. It is widely acknowledged that there is insufficient information available to determine whether prolonged exposure to low levels of these substances is having an impact on the microbial ecology in such environments. In this study we attempt to measure the effects of exposing cultures of Pseudomonas putida KT2440 (UWC1) to six pharmaceuticals by looking at differences in metabolite levels. Initially, we used Fourier transform infrared (FT-IR) spectroscopy coupled with multivariate analysis to discriminate between cell cultures exposed to different pharmaceuticals. This suggested that on exposure to propranolol there were significant changes in the lipid complement of P. putida. Metabolic profiling with gas chromatography-mass spectrometry (GC-MS), coupled with univariate statistical analyses, was used to identify endogenous metabolites contributing to discrimination between cells exposed to the six drugs. This approach suggested that the energy reserves of exposed cells were being expended and was particularly evident on exposure to propranolol. Adenosine triphosphate (ATP) concentrations were raised in P. putida exposed to propranolol. Increased energy requirements may be due to energy dependent efflux pumps being used to remove propranolol from the cell.

Assessing the treatment of acetaminophen-contaminated brewery wastewater by an anaerobic packed-bed reactor

The treatment of high-strength organic brewery wastewater with added acetaminophen (AAP) by an anaerobic digester was investigated. An anaerobic packed-bed reactor (APBR) was operated as a continuous process with an organic loading rate of 1.5-g COD per litre per day and a hydraulic retention time of three days. The results of steady-state analysis showed that the greatest APBR performances for removing COD and TOC were as high as 98 and 93%, respectively, even though the anaerobic digestibility after adding the different AAP concentrations of 5, 10 and 15 mg L(-1) into brewery wastewater can affect the efficiency of organic matter removal. The average CH4 production decreased from 81 to 72% is counterbalanced by the increased CO2 production from 11 to 20% before and after the injection of AAP, respectively. The empirical kinetic models for substrate utilisation and CH4 production were used to predict that, under unfavourable conditions, the performance of the APBR treatment process is able to remove COD with an efficiency of only 6.8%.

Photocatalytic transformation of acesulfame: Transformation products identification and embryotoxicity study

Artificial sweeteners have been recognized as emerging contaminants due to their wide application, environmental persistence and ubiquitous occurrence. Among them, acesulfame has attracted much attention. After being discharged into the environment, acesulfame undergoes photolysis naturally. However, acesulfame photodegradation behavior and identity of its transformation products, critical to understanding acesulfame's environmental impact, have not been thoroughly investigated. The present study aimed to fill this knowledge gap by a laboratory simulation study in examining acesulfame transformation products and pathways under UV-C photolysis in the presence of TiO2. Photodegradation products of acesulfame were isolated and analyzed using the LC-IM-QTOF-MS coupled with LC Ion Trap MS in the MS(n) mode. Our results show six new transformation products that have not been previously identified. The molecular structures and transformation pathways were proposed. Further embryotoxicity tests showed that acesulfame transformation products at the low g L(-1) level produced significant adverse effects in tail detachment, heart rate, hatching rate and survival rate during fish embryo development. The identification of additional transformation products with proposed transformation pathways of acesulfame, the increased toxicity of acesulfame after photolysis, and the fact that the accumulation of acesulfame transformation products is increasingly likely make acesulfame contamination even more important. Water resource control agencies need to consider legislation regarding acesulfame and other artificial sweeteners, while further studies are carried out, in order to protect the safety of this most vital resource.

Germ-free sea bass Dicentrarchus labrax larval model: a valuable tool in the study of host-microbe interactions

A thorough understanding of host-microbe interactions is crucial for more efficient disease management in the marine larviculture industry. As demonstrated in terrestrial animal research, gnotobiotic systems (involving animals cultured in germ-free conditions or inoculated with known microorganisms) are excellent tools to extend our understanding of the mechanisms involved in host-microbe interactions and allow the evaluation of new treatments for diseases. In this study, we introduce a germ-free European sea bass Dicentrarchus labrax larval model, independent of the continuous addition of antimicrobial agents. This model has an experimental set-up that allows addition of live feed to the larvae without compromising the germ-free status. This model will facilitate and render aquaculture research more effective in terms of mitigation fish larval diseases.