Pharmaceuticals and personal care products: A critical review of the impacts on fish reproduction

Hormones and fish monosex farming: A spotlight on immunity

Aquaculture is a promising and developing industry worldwide. One of the first step in monosex culturing, particularly in Nile tilapia, is the production of all-male fry; hormones are widely used in this respect. It is known that exogenous treatment with hormones disrupts various systems in the body including the immune and endocrine systems. There has been a growing interest in how hormones shape the biology of the fish. Many researchers all over the world explored how androgen can interact with many of the body systems; however, rarely any of them tried to improve the hormonal method or to find an alternative. The gate is open for research in this field. This review focusses on the potential effects of hormones, particularly androgens on fish immunity, and the up to date solutions (however, they are rare).

Occurrence and environmental impact of pharmaceutical residues from conventional and natural wastewater treatment plants in Gran Canaria (Spain)

The presence and fate of pharmaceutical residues in environmental samples are of great interest. There is a vast number of studies published regarding their input, presence, effects and risks in ecosystems. Moreover, it has been demonstrated that the primary source of input of these contaminants in the environment is from Wastewater Treatment Plants (WWTPs). It is therefore essential to evaluate the efficiency of commonly used treatments and the necessity of applying novel purification processes in order to eliminate or reduce the concentration of pharmaceuticals from wastewater or from the effluent of WWTPs. The aim of this work was to quantify twenty-three pharmaceutical compounds in the aqueous phase at different stages of a conventional and a natural WWTP situated in Gran Canaria (Spain). The results indicate concentration levels in the range of 0.004±0.001 to 59.2±11.7μgL^-1 and 0.018±0.001 to 148±14.7μgL^-1 from conventional and natural WWTPs, respectively. Better efficiency was, however, offered by the conventional WWTP with a removal median of 99.7%. In addition, the impact on different aquatic organisms (algae, daphnids and fish) was assessed in terms of risk quotients. The results reveal a possible highly harmful effect towards organisms by gemfibrozil, ibuprofen and ofloxacin.

Occurrences and removal of pharmaceuticals and personal care products (PPCPs) in drinking water and water/sewage treatment plants: A review

In recent years, many of micropollutants have been widely detected because of continuous input of pharmaceuticals and personal care products (PPCPs) into the environment and newly developed state-of-the-art analytical methods. PPCP residues are frequently detected in drinking water sources, sewage treatment plants (STPs), and water treatment plants (WTPs) due to their universal consumption, low human metabolic capability, and improper disposal. When partially metabolized PPCPs are transferred into STPs, they elicit negative effects on biological treatment processes; therefore, conventional STPs are insufficient when it comes to PPCP removal. Furthermore, the excreted metabolites may become secondary pollutants and can be further modified in receiving water bodies. Several advanced treatment systems, including membrane filtration, granular activated carbon, and advanced oxidation processes, have been used for the effective removal of individual PPCPs. This review covers the occurrence patterns of PPCPs in water environments and the techniques adopted for their treatment in STP/WTP unit processes operating in various countries. The aim of this review is to provide a comprehensive summary of the removal and fate of PPCPs in different treatment facilities as well as the optimum methods for their elimination in STP and WTP systems.

Photolytic degradation of the β-blocker nebivolol in aqueous solution

Nebivolol (NEB) is one of the top-sold prescription drugs belonging to the third generation of beta-blockers. However, so far, occurrence data in the environment are lacking. Within this study NEB has been found for the first time in effluent samples of wastewater treatment plants in Germany with an average concentration of 13 ng L^-1. Its photodegradation behavior in the environment and in technical processes is largely unknown. To fill this gap, three different UV treatment procedures (UV-C at 254 nm, UV-B at 312 nm and UV-A at 365 nm) were investigated in three different matrices: pure water, pure water in presence of the hydroxyl radical (OH) scavenger tert.-butanol and real wastewater. No elimination was observed during UV-A treatment. In contrast, NEB degradation during UV-B and UV-C treatment followed pseudo first order reaction kinetics, with highest removal rate during UV-C treatment in pure water (k = 7.8 × 10^-4 s^-1). The rate constant for UV-C irradiation decreased to 2.9 × 10^-4 s^-1 in the presence of the OH scavenger and in the presence of the wastewater matrix. The rate constant for the UV-B lamp was 4.4 × 10^-4 s^-1, Three transformation products were identified after UV-B and UV-C photolytic degradation using high resolution mass spectrometry. The main photoreaction is the substitution of the fluorine atoms of NEB by hydroxyl groups. A photolytic cleavage of the CF bond can be excluded as the high bond dissociation energy of aromatic CF bonds (525 kJ mol^-1), exceeds the energy of electromagnetic radiation applied in the present study (≥254 nm, i.e., max. 471 kJ E^-1). The quantum yields for NEB degradation for the UV-C lamp achieved in pure water, the OH scavenged system and wastewater matrix were Φ_deg = 0.53, 0.19 and 0.22, respectively. For UV-B Φ_deg was 0.023 ± 0.003, noticeable differences in quantum yield were not found. The photooxidation involves reactive oxygen species such as superoxide and singlet oxygen. These oxidative species may be formed upon reaction of photo-excited NEB with oxygen.

Modulation of the stress response in wild fish is associated with variation in dissolved nitrate and nitrite

Disruption of non-reproductive endocrine systems in wildlife by chemicals has received little attention but represents a potentially significant problem. Nitrate is a major anthropogenic contaminant in the freshwater aquatic environment and has been identified as a potential disrupter of endocrine function in aquatic animals. This study was conducted to investigate the relationship between the function of the neuroendocrine stress axis in fish and inorganic N loading along reaches of rivers receiving cumulative point source and diffuse chemical inputs. To accomplish this, the responsiveness of the stress axis, quantified as the rate of release of cortisol to water across the gills during exposure to a standardised stressor, was measured in three-spined sticklebacks (Gasterosteus aculeatus L.) resident at three sites on each of four rivers in north-west England. The magnitude of the stress response in fish captured at the sites furthest downstream on all rivers was more than twice that of fish captured at upstream sites. Site-specific variation in stress axis reactivity was better explained by between-site variation in concentrations of dissolved nitrate, nitrite, and ammonia than by the concentration of wastewater treatment works effluent. An increase in the magnitude of the stress response was seen among sticklebacks at sites where long-term averaged concentrations of NH₃-N, NO₃-N and NO₂-N exceeded 0.6, 4.0 and 0.1 mg/L respectively. These data suggest that either (i) inorganic N is a better surrogate than wastewater effluent concentration for an unknown factor or factors affecting stress axis function in fish, or (ii) dissolved inorganic N directly exerts a disruptive influence on the function of the neuroendocrine stress axis in fish, supporting concerns that nitrate is an endocrine-modulating chemical.

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

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

Municipal wastewater effluent licensing: A global perspective and recommendations for best practice

Advances in wastewater treatment have greatly improved the quality of municipal wastewater effluents in many parts of the world, but despite this, treated wastewaters can still pose a risk to the environment. Licensing plays a crucial role in the regulation of municipal wastewater effluents by setting standards or limits designed to protect the economic, environmental and societal values of waterbodies. Traditionally these standards have focused on physical and chemical water quality parameters within the discharge itself, however these approaches do not adequately account for emerging contaminants, potential effects of chemical mixtures, or variations in the sensitivity and resilience of receiving environments. In this review we focus on a number of industrialised countries and their approach to licensing. We consider how we can ensure licensing is effective, particularly when considering the rapid changes in our understanding of the impacts of discharges, the technical advances in our ability to detect chemicals at low concentrations and the progress in wastewater treatment technology. In order to meet the challenges required to protect the values of our waterways, licensing of effluents will need to ensure that there is no disconnect between the core values to be protected and the monitoring system designed to scrutinise performance of the WWTP. In many cases this may mean an expansion in the monitoring approaches used for both the effluent itself and the receiving waterbody.

Neuroendocrine disruption of organizational and activational hormone programming in poikilothermic vertebrates

In vertebrates, sexual differentiation of the reproductive system and brain is tightly orchestrated by organizational and activational effects of endogenous hormones. In mammals and birds, the organizational period is typified by a surge of sex hormones during differentiation of specific neural circuits; whereas activational effects are dependent upon later increases in these same hormones at sexual maturation. Depending on the reproductive organ or brain region, initial programming events may be modulated by androgens or require conversion of androgens to estrogens. The prevailing notion based upon findings in mammalian models is that male brain is sculpted to undergo masculinization and defeminization. In absence of these responses, the female brain develops. While timing of organizational and activational events vary across taxa, there are shared features. Further, exposure of different animal models to environmental chemicals such as xenoestrogens such as bisphenol A-BPA and ethinylestradiol-EE2, gestagens, and thyroid hormone disruptors, broadly classified as neuroendocrine disrupting chemicals (NED), during these critical periods may result in similar alterations in brain structure, function, and consequently, behaviors. Organizational effects of neuroendocrine systems in mammals and birds appear to be permanent, whereas teleost fish neuroendocrine systems exhibit plasticity. While there are fewer NED studies in amphibians and reptiles, data suggest that NED disrupt normal organizational-activational effects of endogenous hormones, although it remains to be determined if these disturbances are reversible. The aim of this review is to examine how various environmental chemicals may interrupt normal organizational and activational events in poikilothermic vertebrates. By altering such processes, these chemicals may affect reproductive health of an animal and result in compromised populations and ecosystem-level effects.

Effects of triclosan on bacterial community composition and Vibrio populations in natural seawater microcosms

Pharmaceuticals and personal care products, including antimicrobials, can be found at trace levels in treated wastewater effluent. Impacts of chemical contaminants on coastal aquatic microbial community structure and pathogen abundance are unknown despite the potential for selection through antimicrobial resistance. In particular, Vibrio, a marine bacterial genus that includes several human pathogens, displays resistance to the ubiquitous antimicrobial compound triclosan. Here we demonstrated through use of natural seawater microcosms that triclosan (at a concentration of ~5 ppm) can induce a significant Vibrio growth response (68-1,700 fold increases) in comparison with no treatment controls for three distinct coastal ecosystems: Looe Key Reef (Florida Keys National Marine Sanctuary), Doctors Arm Canal (Big Pine Key, FL), and Clam Bank Landing (North Inlet Estuary, Georgetown, SC). Additionally, microbial community analysis by 16 S rRNA gene sequencing for Looe Key Reef showed distinct changes in microbial community structure with exposure to 5 ppm triclosan, with increases observed in the relative abundance of Vibrionaceae (17-fold), Pseudoalteromonadaceae (65-fold), Alteromonadaceae (108-fold), Colwelliaceae (430-fold), and Oceanospirillaceae (1,494-fold). While the triclosan doses tested were above concentrations typically observed in coastal surface waters, results identify bacterial families that are potentially resistant to triclosan and/or adapted to use triclosan as a carbon source. The results further suggest the potential for selection of Vibrio in coastal environments, especially sediments, where triclosan may accumulate at high levels.

Pay attention to non-wastewater emission pathways of pharmaceuticals into environments

Pharmaceuticals have been widely detected in the aquatic environment and demonstrated to be potential risks to humans and the environment. Understanding emission pathways of pharmaceuticals is essential to the control of pharmaceutical contamination for environmental management. The present study is aimed at testing the hypothesis that non-wastewater pathway is also significant to the emission of pharmaceuticals into the environment. To this end, we compared the actual production with the amount of 12 antibiotics obtained by back calculation from sewage concentrations in Beijing, Guangzhou and Chongqing. The results showed that for over a half of investigated antibiotics, the emission through non-wastewater pathways accounted for approximately 30-80% of the total emission, varying with individual antibiotics. It was revealed that non-wastewater emission pathways could be of significance for pharmaceuticals emitted into the environment, of which disposed by household waste could be among the most important non-wastewater pathways.

Hazard of pharmaceuticals for aquatic environment: Prioritization by structural approaches and prediction of ecotoxicity

Active Pharmaceutical Ingredients (APIs) are recognized as Contaminants of Emerging Concern (CEC) since they are detected in the environment in increasing amount, mainly in aquatic compartment, where they may be hazardous for wildlife. The huge lack of experimental data for a large number of end-points requires tools able to quickly highlight the potentially most hazardous and toxic pharmaceuticals, focusing experiments on the prioritized compounds. In silico tools, like QSAR (Quantitative Structure-Activity Relationship) models based on structural molecular descriptors, can predict missing data for toxic end-points necessary to prioritize existing, or even not yet synthesized chemicals for their potential hazard. In the present study, new externally validated QSAR models, specific to predict acute toxicity of APIs in key organisms of the three main aquatic trophic levels, i.e. algae, Daphnia and two species of fish, were developed using the QSARINS software. These Multiple Linear regressions - Ordinary Least Squares (MLR-OLS) models are based on theoretical molecular descriptors calculated by free PaDEL-Descriptor software and selected by Genetic Algorithm. The models are statistically robust, externally predictive and characterized by a wide structural applicability domain. They were applied to predict acute toxicity for a large set of APIs without experimental data. Then predictions were processed by Principal Component Analysis (PCA) and a trend, driven by the combination of toxicities for all the studied organisms, was highlighted. This trend, named Aquatic Toxicity Index (ATI), allowed the raking of pharmaceuticals according to their potential toxicity upon the whole aquatic environment. Finally a QSAR model for the prediction of this Aquatic Toxicity Index (ATI) was proposed to be applicable in QSARINS for the screening of existing APIs for their potential hazard and the a priori chemical design of not environmentally hazardous APIs.

Long-term effects of antibiotics, norfloxacin, and sulfamethoxazole, in a partial life-cycle study with zebrafish (Danio rerio): effects on growth, development, and reproduction

A partial life-cycle study with zebrafish (Danio rerio) was conducted to evaluate the long-term effects of antibiotics, norfloxacin (NOR) and sulfamethoxazole (SMX). A series of bio-endpoints correlated to the growth, development, and reproduction was assessed. The results showed that the body weight and the condition factor were depressed by SMX at 200 μg/L during the growth period. Meanwhile, the activities of metabolic enzyme (ethoxyresorufin O-deethylase, EROD) and antioxidant enzymes (superoxide dismutase, SOD and catalase, CAT) were stimulated in all cases. The consequences of parental exposure to antibiotics for the next generation were also examined. The egg production of parents were depressed by the 200 μg/L NOR and SMX alone or in combination. Similarly, decreased hatching, survival, and enhanced development abnormality of the next generation also occurred after parental exposure to SMX at the highest concentration. The heartbeat however was not altered in all cases. Furthermore, there was no significant difference in the bio-endpoints between the combined and individual treatment in most cases, with the exception of lower EROD activity and egg production in the co-treatment. The results suggest that long-term exposure to NOR and SMX at environmentally relevant concentrations, individually and in a mixture, may not significantly pose a threat to the growth, development, and reproduction of zebrafish, and an adverse effect may be expected at high concentration.

A case of contagious toxicity? Isoprostanes as potential emerging contaminants of concern

Isoprostanes are useful biomarkers of human and animal health, being representative of oxidative stress processes, and having biological impacts associated with toxicity and disease. Isoprostanes are also chemically stable, a property facilitating population-level health assessments through wastewater sampling. However, as biologically-active entities, the presence of isoprostanes in domestic effluents could have toxic impacts on biota in receiving environments. As such it is proposed that isoprostanes are emerging organic contaminants of particular concern. Fish and aquatic invertebrates may be affected by the presence of isoprostanes in wastewaters through mechanisms such as reproductive impairment, cardiovascular disturbance and/or oxidative stress. This would represent a unique scenario of "contagious" toxicity, whereby human health has a direct toxicological consequence on aquatic animal health.

Rapid Screening for Exposure to "Non-Target" Pharmaceuticals from Wastewater Effluents by Combining HRMS-Based Suspect Screening and Exposure Modeling

Active pharmaceutical ingredients (APIs) have raised considerable concern over the past decade due to their widespread detection in water resources and their potential to affect ecosystem health. This triggered many attempts to prioritize the large number of known APIs to target monitoring efforts and testing of fate and effects. However, so far, a comprehensive approach to screen for their presence in surface waters has been missing. Here, we explore a combination of an automated suspect screening approach based on liquid chromatography coupled to high-resolution mass spectrometry and a model-based prioritization using consumption data, readily predictable fate properties and a generic mass balance model for activated sludge treatment to comprehensively detect APIs with relevant exposure in wastewater treatment plant effluents. The procedure afforded the detection of 27 APIs that had not been covered in our previous target method, which included 119 parent APIs. The newly detected APIs included seven compounds with a high potential for bioaccumulation and persistence, and also three compounds that were suspected to stem from point sources rather than from consumption as medicines. Analytical suspect screening proved to be more selective than model-based prioritization, making it the method of choice for focusing analytical method development or fate and effect testing on those APIs most relevant to the aquatic environment. However, we found that state-of-the-practice exposure modeling used to predict potential high-exposure substances can be a useful complement to point toward oversights and known or suspected detection gaps in the analytical method, most of which were related to insufficient ionization.

Insight into the adsorption of PPCPs by porous adsorbents: Effect of the properties of adsorbents and adsorbates

Adsorption is an efficient method for removal of pharmaceuticals and personal care products (PPCPs). Magnetic resins are efficient adsorbents for water treatment and exhibit potential for PPCP removal. In this study, the magnetic hypercrosslinked resin Q100 was used for adsorption of PPCPs. The adsorption behavior of this resin was compared with those of two activated carbons, namely, Norit and F400D. Norit exhibited the fastest adsorption kinetics, followed by Q100. Norit featured a honeycomb shape and long-range ordered pore channels, which facilitated the diffusion of PPCPs. Moreover, the large average pore size of Q100 reduced diffusion resistance. The adsorbed amounts of 11 PPCPs on the three adsorbents increased with increasing adsorbate hydrophobicity. For Q100, a significant linear correlation was observed between the adsorption performance for PPCPs and hydrophobicity (logD value) of adsorbates (R(2) = 0.8951); as such, PPCPs with high logD values (>1.69) could be efficiently removed. Compared with those of Norit and F400D, the adsorption performance of Q100 was less affected by humic acid because of the dominant hydrophobic interaction. Furthermore, Q100 showed improved regeneration performance, which renders it promising for PPCP removal in practical applications.

An aggregate analysis of personal care products in the environment: Identifying the distribution of environmentally-relevant concentrations

Over the past 3-4 decades, per capita consumption of personal care products (PCPs) has steadily risen, resulting in increased discharge of the active and inactive ingredients present in these products into wastewater collection systems. PCPs comprise a long list of compounds employed in toothpaste, sunscreen, lotions, soaps, body washes, and insect repellants, among others. While comprehensive toxicological studies are not yet available, an increasing body of literature has shown that PCPs of all classes can impact aquatic wildlife, bacteria, and/or mammalian cells at low concentrations. Ongoing research efforts have identified PCPs in a variety of environmental compartments, including raw wastewater, wastewater effluent, surface water, wastewater solids, sediment, groundwater, and drinking water. Here, an aggregate analysis of over 5000 reported detections was conducted to better understand the distribution of environmentally-relevant PCP concentrations in, and between, these compartments. The distributions were used to identify whether aggregated environmentally-relevant concentration ranges intersected with available toxicity data. For raw wastewater, wastewater effluent, and surface water, a clear overlap was present between the 25th-75th percentiles and identified toxicity levels. This analysis suggests that improved wastewater treatment of antimicrobials, UV filters, and polycyclic musks is required to prevent negative impacts on aquatic species.