Combined effects of pharmaceuticals, personal care products, biocides and organic contaminants on the growth of Skeletonema pseudocostatum

Toxic effects of triclosan in aquatic organisms: A review focusing on single and combined exposure of environmental conditions and pollutants

Triclosan (TCS) is an antibacterial agent commonly used in personal care products. Due to its widespread use and improper disposal, it is also a pervasive contaminant, particularly in aquatic environments. When released into water bodies, TCS can induce deleterious effects on developmental and physiological aspects of aquatic organisms and also interact with environmental stressors such as weather, metals, pharmaceuticals, and microplastics. Multiple studies have described the adverse effects of TCS on aquatic organisms, but few have reported on the interactions between TCS and other environmental conditions and pollutants. Because aquatic environments include a mix of contaminants and natural factors can correlate with contaminants, it is important to understand the toxicological outcomes of combinations of substances. Due to its lipophilic characteristics, TCS can interact with a wide range of substances and environmental stressors in aquatic environments. Here, we identify a need for caution when using TCS by describing not only the effects of exposure to TCS alone on aquatic organisms but also how toxicity changes when it acts in combination with multiple environmental stressors.

Combined effects of fluoroquinolone antibiotics and organophosphate flame retardants on Microcystis aeruginosa

As freshwater harmful algal blooms continue to rise in frequency and severity, increasing focus is made on the effects of mixed pollutants and the dominant cyanobacterial species Microcystis aeruginosa (M. aeruginosa). However, few studies have investigated whether M. aeruginosa has a synergistic relationship with two common pollutants, namely, organophosphate flame retardants (OPFRs) and fluoroquinolone antibiotics (FQs). In this paper, three FQs and three OPFRs commonly detected in freshwaters were selected to construct a ternary mixture of FQs, a ternary mixture of OPFRs, and a six-component mixture of OPFRs and FQs. The effects of single substance and mixture on the growth of M. aeruginosa were determined at 24, 48, 72, and 96 h, and the toxicities of the mixture were evaluated by concentration addition model and independent action model. The results showed that the mixture of FQs and the mixture of OPFRs do not show toxicological interaction. However, partial mixtures of OPFRs and FQs showed antagonism or synergism at different concentrations and times. This indicated that combined toxicities of OPFRs and FQs on M. aeruginosa were mixture ratio dependent, concentration dependent and time dependent. This study improves our understanding of the role of OPFRs and FQs in cyanobacterial outbreaks of Microcystis.

Environmental impacts of the ultraviolet filter oxybenzone

Organic UV filters are emerging contaminants with increasing evidence of their negative impact on environmental health and water quality. One of the most common and environmentally relevant organic UV filters is oxybenzone (OBZ). While much of the initial focus has been on investigating the interaction of OBZ with coral reefs, there have been several recent studies that indicate that organic UV filters are affecting other environmental endpoints, including marine animals, algae, and plants. OBZ has been found to bioaccumulate in marine animals such as fish and mussels and then potentially acting as an endocrine disruptor. In plants, exposure to OBZ has been associated with decreased photosynthesis, inhibited seed germination, and impaired plant growth. In this review, we summarize the current state of knowledge regarding the environmental impacts of OBZ and suggest potential future directions.

Individual and combined toxicity of microplastics and diuron differs between freshwater and marine diatoms

Microplastics are considered as the emerging pollutants, which not only directly affect aquatic organisms, but also causes combined pollution by adsorbing other pollutants. Diuron, as one of the most widely used herbicides, is frequently monitored in the aquatic environment for its adverse effects on aquatic organisms. However, little is known about the combined toxicity of microplastics and diuron to aquatic organisms, especially diatoms. In this study, freshwater diatom (Cyclotella meneghiniana) and marine diatom (Skeletonema costatum) were selected to study the individual and combined toxicity of microplastics (polystyrene, 0.6- 1.0 μm) and diuron. Experimental concentrations of microplastics and diuron were set at 50 mg/L and 100 μg/L, respectively, which have been shown to significantly inhibit the growth of aquatic organisms. Results suggested that both single microplastics and single diuron significantly inhibited the growth of the two diatoms, while significant SOD and MDA increase were only found in single diuron exposure. For diatoms exposed to individual microplastics, the microplastic particles adsorbed inside Cyclotella sp. and those aggregated around Skeletonema sp. were the major factor inhibiting the growth of diatom, respectively. According to the independent action model, the combined toxicity for both diatoms were all antagonistic. The adsorption behavior of microplastics to diuron alleviated the intracellular damage to diatoms caused by diuron, and the oxidative stress induced by diuron mitigated the physical damage to diatoms caused by microplastics. Collectively, our findings suggest that the co-existence of microplastics and diuron may affect their respective toxicity to diatoms. The mechanism of this "cross-phenomenon" between microplastics and diuron and their combined toxicity to different aquatic organisms need to be further studied.

Cytotoxicity of BP-3 and BP-4: Blockage of extrusion pumps, oxidative damage and programmed cell death on Chlamydomonas reinhardtii

The health concern associated with the dangers related to exposure to UV radiation has led to an increase in the use of sunscreens containing UV-filters that can reach aquatic environments and possibly affect ecosystems. Benzophenone-3 (BP-3) and benzophenone-4 (BP-4) are two of the most used UV-filters. In the present work, the microalga Chlamydomonas reinhardtii was exposed to several concentrations of both chemicals. To evaluate their potential cytotoxicity on microalgal cells, different parameters were analysed including fast response biomarkers (increase in intracellular free Ca²⁺) as well as biomarkers related with the presence of oxidative stress (lipid peroxidation), energy metabolism (photosynthetic yield and cytoplasmic lipid accumulations), cell division (proliferation and F-actin content), programmed cell death (PCD) (caspase activation and DNA fragmentation) and possible mechanisms of resistance to xenobiotics (operation of extrusion pumps and presence of autophagic vacuoles). Results showed an increment of the percentage of cells with cytosolic free Ca²⁺ that could act as a secondary messenger in response to the stress. A decrease in photosynthetic yield and an increase in cytoplasmic lipid accumulations and lipid peroxidation levels were also detected. In addition, a decrease in cell proliferation was observed, linked to a decrease in the percentage of cells with F-actin. The increase observed in the microalgal population with caspase activity, together with the DNA fragmentation and the alterations in the cytoskeleton, suggested the induction of processes linked to PCD. Moreover, a blockage of extrusion pumps, which could be related to the toxicity mechanism of these compounds, and an increase in autophagic vacuoles, as an attempt to repair the damage caused by benzophenones, were detected. Overall, these biomarkers indicate that both UV-filters can be a serious threat to non-target photosynthetic microorganisms in aquatic environments, although BP-3 affected C. reinhardtii more markedly.

The MicroClimate Screen - A microscale climate exposure system for assessing the effect of CO2, temperature and UV on marine microalgae

Global warming and anthropogenic activities are changing the ocean, inducing profound impacts on marine life and ecosystems from changing physical and chemical factors in and above the water column. Rising surface temperatures, ocean acidification, and seasonal variations in UV radiation (UVR), modulated by water clarity and sea-ice extent, affect life cycles of the marine food-web, and directly or indirectly also the global carbon fixation. Diatoms, pelagic microalgae that are responsible for 40% of the marine productivity, have limited capability to avoid exposure to changing ocean conditions, and hence, highly relevant for model studies of the influence of climate change on growth and productivity in the marine environment. A plate-based high-throughput exposure system was constructed to assess the biological effects from relevant climate change factors on the diatom Skeletonema pseudocostatum, conducted as a chronic toxicity tests over 72 h periods. The exposure system consisted of a micro-climate unit and a light-exposure unit, enabling accurate regulation of pCO₂, temperature, UVR and photosynthetic active radiation (PAR). Changes in physical factors, including pH, dissolved inorganic carbon (DIC), total alkalinity (TA), temperature and salinity in the medium, as well as reduction in growth were characterised to demonstrate performance of the micro exposure system. The results demonstrate that the exposure system successfully simulated ocean acidification and could maintain stable temperature (CV < 3%), PAR and UVR irradiance (CV < 8%). Growth inhibition responses were typically dose-dependent and verified that the micro-exposure system could be used to assess effects and adaptions to climate-relevant stressors.

Occurrence and environmental hazard of organic UV filters in seawater and wastewater from Gran Canaria Island (Canary Islands, Spain)

Organic ultraviolet (UV) filters are used in personal care products, but they are also added to industrial products and are constantly released to the environment. This study analyses the occurrence of 8 widely used organic UV filters in seawater from three beaches on the Gran Canaria Island (Spain) and in three wastewater treatment plants (WWTPs) by taking samples from influents and effluents. It also discusses the target compounds' post-treatment removal efficiencies. Sampling was carried out for 6 months and analytes were extracted by solid phase extraction with Sep-pak C18 cartridges. They were determined by ultra-high performance liquid chromatography coupled to mass spectrometry in tandem. The potential environmental hazard associated with the found concentrations was also assessed for marine organisms. Different target compounds were detected on the analysed beaches and in the wastewater. Benzophenone-3 (BP3) was the most recurrent compound in the seawater samples (frequency detection of 83%) and also in wastewater influents and effluents (measured in all the samples). However, the highest concentrations for seawater (172 μg L^-1) and influent wastewater (208 μg L^-1) corresponded to octocrylene, while methylene bis-benzotriazolyltetramethylbutylphenol was the compound most concentrated in secondary treatment effluent (34.0 μg L^-1) and BP3 in tertiary treatment effluent (8.07 μg L^-1). All the analysed samples showed that at least one target UV filter was present. Regarding the removal efficiencies of these compounds in the studied WWTPs, consistent differences between the target compounds were observed in influent concentration terms, where the average removal rates were higher than 50% for most of the compounds. Conventional treatment is unable to completely remove many studied compounds, while tertiary treatment acts as an additional elimination for some of them. An environmental hazard quotient above 1 was found for octocrylene, benzophenone-3 and 4-methylbenzylidene camphor, which indicates a potential high hazard for living species if these compounds are present.

Oxybenzone contamination from sunscreen pollution and its ecological threat to Hanauma Bay, Oahu, Hawaii, U.S.A

Hanauma Bay is a 101-acre bay created by the partial collapse of a volcanic cone and once supported a vibrant coral reef system. It is the most popular swimming area in the Hawaiian Islands and has been reported to have averaged between 2.8 and 3.5 million visitors a year between the 1980s and the 2010s, with visitors averaging between 3000-4000 a day and peaking around 10,000-13,000 per day. Concentrations of oxybenzone and other common UV filters were measured in subsurface water samples and in sands from the beach-shower areas in Hanauma Bay. Results demonstrate that beach showers also can be a source of sunscreen environmental contamination. Hydrodynamic modeling indicates that oxybenzone contamination within Hanauma Bay's waters could be retained between 14 and 50 h from a single release event period. Focusing on only oxybenzone, two different Hazard and Risk Assessment analyses were conducted to determine the danger of oxybenzone to Hanauma Bay's coral reef system. Results indicate that oxybenzone contamination poses a significant threat to the wildlife of Hanauma Bay. To recover Hanauma Bay's natural resources to a healthy condition and to satisfactorily conserve its coral reef and sea grass habitats, effective tourism management policies need to be implemented that mitigate the threat of sunscreen pollution.

Environmental estrogens in surface water and their interaction with microalgae: A review

Environmental estrogens (EEs) have received extensive attention because they interfere with biological endocrine and reproduction systems by mimicking, antagonizing, or otherwise affecting the actions of endogenous hormones. Additionally, harmful algal blooms have become a global problem in surface water. Microalgae, as an essential primary producer, is especially important for aquatic life and the entire ecosystem. The presence of EEs in surface water may be a potential promoting factor for algal blooms, and microalgae may have effects on the degradation of EEs. This review focuses on the distribution and pollution characteristics of EEs in global surface waters, effects of single and mixed EEs on microalgae regarding growth and toxin production, mechanisms of EEs on microalgae at the cellular and molecular level. The impacts of microalgae on EEs were also discussed. This review provides a risk assessment of EEs and identifies essential clues that will aid in formulating and revising the relevant standards of surface water regarding EEs, which is significant for ecosystems and human health.

Influence of cosubstrate and hydraulic retention time on the removal of drugs and hygiene products in sanitary sewage in an anaerobic Expanded Granular Sludge Bed reactor

Diclofenac (DCF), ibuprofen (IBU), propranolol (PRO), triclosan (TCS) and linear alkylbenzene sulfonate (LAS) can be recalcitrant in Wastewater Treatment Plants (WWTP). The removal of these compounds was investigated in scale-up (69 L) Expanded Granular Sludge Bed (EGSB) reactor, fed with sanitary sewage from the São Carlos-SP (Brazil) WWTP and 200 mg L^-1 of ethanol. The EGSB was operated in three phases: (I) hydraulic retention time (HRT) of 36±4 h; (II) HRT of 20±2 h and (III) HRT of 20±2 h with ethanol. Phases I and II showed no significant difference in the removal of LAS (63 ± 11-65 ± 12 %), DCF (37 ± 18-35 ± 11 %), IBU (43 ± 18-44 ± 16 %) and PRO (46 ± 25-51 ± 23 %) for 13±2-15 ± 2 mg L^-1, 106 ± 32-462 ± 294 μg L^-1, 166 ± 55-462 ± 213 μg L^-1 and 201 ± 113-250 ± 141 μg L^-1 influent, respectively. Higher TCS removal was obtained in phase I (72 ± 17 % for 127 ± 120 μg L^-1 influent) when compared to phase II (51 ± 13 % for 135 ± 119 μg L^-1 influent). This was due to its greater adsorption (40 %) in the initial phase. Phase III had higher removal of DCF (42 ± 10 % for 107 ± 26 μg L^-1 influent), IBU (50 ± 15 % for 164 ± 47 μg L^-1 influent) and TCS (85 ± 15 % for 185 ± 148 μg L^-1 influent) and lower removal of LAS (35 ± 14 % for 12 ± 3 mg L^-1 influent) and PRO (-142 ± 177 % for 188 ± 88 μg L^-1 influent). Bacteria similar to Syntrophobacter, Smithella, Macellibacteroides, Syntrophus, Blvii28_wastewater-sludge_group and Bacteroides were identified in phase I with relative abundance of 3.1 %-4.7 %. Syntrophobacter was more abundant (15.4 %) in phase II, while in phase III, it was Smithella (12.7 %) and Caldisericum (15.1 %). Regarding the Archaea Domain, Methanosaeta was more abundant in phases I (84 %) and II (67 %), while in phase III it was Methanobacterium (86 %).

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.

Susceptibility of phytoplankton to the increasing presence of active pharmaceutical ingredients (APIs) in the aquatic environment: A review

Human and veterinary pharmaceuticals either in the form of un-metabolized, incompletely metabolized, and metabolized drugs are increasingly present in aquatic ecosystems. These active pharmaceutical ingredients from pharmaceutical industries, hospitals, agricultural, and domestic discharges find their way into water systems - where they adversely affect non-target organisms like phytoplankton. Different aspects of phytoplankton life; ranging from growth, reproduction, morphology, physiology, biochemical composition, oxidative response, proteomics, and transcriptomics are altered by pharmaceuticals. This review discusses the currently available information on the susceptibility of phytoplankton to the ever-increasing presence of pharmaceutical products in the aquatic environment by focusing on the effect of APIs on the physiology, metabolome, and proteome profiles of phytoplankton. We also highlight gaps in literature concerning the salient underlining biochemical interactions between phytoplankton communities and pharmaceuticals that require an in-depth investigation. This is all in a bid to understand the imminent dangers of the contamination of water bodies with pharmaceutical products and how this process unfavorably affects aquatic food webs.

A novel study for joint toxicity of typical aromatic compounds in coal pyrolysis wastewater by Tetrahymena thermophile

The coal pyrolysis wastewater (CPW) contributed to aquatic environment contamination with amount of aromatic pollutants, and the research on joint toxicity of the mixture of aromatic compounds was vital for environmental protection. By using Tetrahymena thermophile as non-target organism, the joint toxicity of typical nonpolar narcotics and polar narcotics in CPW was investigated. The results demonstrated that the nonpolar narcotics exerted chronic and reversible toxicity by hydrophobicity-based membrane perturbation, while polar narcotics performed acute toxicity by irreversible damage of cells. As the most hydrophobic nonpolar narcotics, indole and naphthalene caused the highest joint toxicity in 24 h with the lowest EC_50mix (24.93 mg/L). For phenolic compounds, the combination of p-cresol and p-nitrophenol also showed the top toxicity (EC_50mix = 10.9 mg/L) with relation to high hydrophobicity, and the joint toxicity was obviously stronger and more acute than that of nonpolar narcotics. Furthermore, by studying the joint toxicity of nonpolar narcotics and polar narcotics, the hydrophobicity-based membrane perturbation was the first step of toxicity effects, and afterwards the acute toxicity induced by electrophilic polar substituents of phenols dominated joint toxicity afterwards. This toxicity investigation was critical for understanding universal and specific effects of CPW to aquatic organisms.

Comparative acute toxicity of benzophenone derivatives and bisphenol analogues in the Asian clam Corbicula fluminea

Among UV-filters, benzophenones are one of the most abundantly used and detected groups in the environment. Bisphenols are also one of the most widely used chemicals in plastics, but their demonstrated deleterious effects on several organisms and humans have led to the production of alternative analogues. However, few comparative studies on the ecotoxicological effects of these derivatives or analogues have been carried out. The present study aimed to investigate the effects of two benzophenones (BP-3 and BP-4) and two bisphenols (BPA and BPS) in a short-term exposure of the freshwater endobenthic bivalve Corbicula fluminea. Clams were exposed for 96 h to several concentrations of the four pollutants: BP-3 (0.63; 1.25; 2.5; 5 mg l^-1), BP-4 (4.75; 9.5; 19; 38 mg l^-1), BPA (3.75; 7.5; 15; 30 mg l^-1), and BPS (2.5; 5; 10; 20 mg l^-1). The comparative acute toxicity of these pollutants was evaluated by the analysis of the post-exposure filtering capacity of clams, lipid peroxidation (LP) levels and the activity of the antioxidant enzymes catalase (CAT) and glutathione reductase (GR). After the exposure period, except for BP-4, the chemicals tested seemed to be detected by clams and provoked valve closure, decreasing filter-feeding in a concentration-dependent manner. Furthermore, C. fluminea exposed to the highest concentrations of BP-3, BP-4 and BPA showed a significant increase in LP, CAT and GR activities with respect to their controls. BP-3 and BPA were the most toxic compounds showing significant differences in all the parameters analysed at the highest concentrations assayed. However, clams exposed to BPS showed only significant alterations in filtration parameters and in GR activity, in the two highest concentrations tested, indicating that this compound was the least toxic to clams. Obtained results highlight the importance of investigating the effects that emerging pollutants have on aquatic organisms.

Pollutant toxicology with respect to microalgae and cyanobacteria

Microalgae and cyanobacteria are fundamental components of aquatic ecosystems. Pollution in aquatic environment is a worldwide problem. Toxicological research on microalgae and cyanobacteria can help to establish a solid foundation for aquatic ecotoxicological assessments. Algae and cyanobacteria occupy a large proportion of the biomass in aquatic environments; thus, their toxicological responses have been investigated extensively. However, the depth of toxic mechanisms and breadth of toxicological investigations need to be improved. While existing pollutants are being discharged into the environment daily, new ones are also being produced continuously. As a result, the phenomenon of water pollution has become unprecedentedly complex. In this review, we summarize the latest findings on five kinds of aquatic pollutants, namely, metals, nanomaterials, pesticides, pharmaceutical and personal care products (PPCPs), and persistent organic pollutants (POPs). Further, we present information on emerging pollutants such as graphene, microplastics, and ionic liquids. Efforts in studying the toxicological effects of pollutants on microalgae and cyanobacteria must be increased in order to better predict the potential risks posed by these materials to aquatic ecosystems as well as human health.

Environmental effects of offshore produced water discharges: A review focused on the Norwegian continental shelf

Produced water (PW), a large byproduct of offshore oil and gas extraction, is reinjected to formations or discharged to the sea after treatment. The discharges contain dispersed crude oil, polycyclic aromatic hydrocarbons (PAHs), alkylphenols (APs), metals, and many other constituents of environmental relevance. Risk-based regulation, greener offshore chemicals and improved cleaning systems have reduced environmental risks of PW discharges, but PW is still the largest operational source of oil pollution to the sea from the offshore petroleum industry. Monitoring surveys find detectable exposures in caged mussel and fish several km downstream from PW outfalls, but biomarkers indicate only mild acute effects in these sentinels. On the other hand, increased concentrations of DNA adducts are found repeatedly in benthic fish populations, especially in haddock. It is uncertain whether increased adducts could be a long-term effect of sediment contamination due to ongoing PW discharges, or earlier discharges of oil-containing drilling waste. Another concern is uncertainty regarding the possible effect of PW discharges in the sub-Arctic Southern Barents Sea. So far, research suggests that sub-arctic species are largely comparable to temperate species in their sensitivity to PW exposure. Larval deformities and cardiac toxicity in fish early life stages are among the biomarkers and adverse outcome pathways that currently receive much attention in PW effect research. Herein, we summarize the accumulated ecotoxicological knowledge of offshore PW discharges and highlight some key remaining knowledge needs.

Antioxidant responses in cyanobacterium Microcystis aeruginosa caused by two commonly used UV filters, benzophenone-1 and benzophenone-3, at environmentally relevant concentrations

Benzophenone-type ultraviolet filters (BPs) have recently been recognized as emerging organic contaminants. In the present study, the cyanobacterium Microcystis aeruginosa was exposed to environmentally relevant levels (0.01-1000 μg L^-1) of benzophenone-1 (BP-1) and benzophenone-3 (BP-3) for seven days. A battery of tested endpoints associated with photosynthetic pigments and oxidative stress was employed for a better understanding of the mode of action. The tested cyanobacterium could uptake the two BPs (27.4-54.9%) from culture media. The two BPs were able to inhibit the production of chlorophyll a (chl-a) and promote the accumulation of carotenoids, leading to unaffected chl-a autofluorescence. Slightly increased malondialdehyde (MDA) contents suggested that BP-1 and BP-3 caused moderate oxidative stress. BP-1 stimulated the activities of superoxide dismutase (SOD), glutathione reductase (GR) and glutathione S-transferase (GST) in M. aeruginosa while BP-3 increased the activities of SOD, GST, and glutathione (GSH), showing a concentration- and time-dependent relationship. The activities of other biomarkers, such as catalase (CAT) and glutathione peroxidase (GPx) fluctuated depending on exposure time and concentration. The overall results suggested that the two BPs can trigger moderate oxidative stress in M. aeruginosa and the tested cyanobacterium was capable of alleviating stress by different mechanisms.

Environmental Water Pollution, Endocrine Interference and Ecotoxicity of 4-tert-Octylphenol: A Review

4-tert-Octylphenol is a degradation product of non-ionic surfactants alkylphenol polyethoxylates as well as raw material for a number of industrial applications. It is a multimedia compound having been detected in all environmental compartments such as indoor air and surface waters. The pollutant is biodegradable, but certain degradation products are more toxic than the parent compound. Newer removal techniques from environmental waters have been presented, but they still require development for large-scale applications. Wastewater treatment by plant enzymes such as peroxidases offers promise in total removal of 4-tert-octylphenol leaving less toxic degradation products. The pollutant's endocrine interference has been well reported but more in oestrogens than in any other signalling pathways through which it is believed to exert toxicity on human and wildlife. In this paper we carried out a review of the activities of this pollutant in environmental waters, endocrine interference and relevance to its toxicities and concluded that inadequate knowledge of its endocrine activities impedes understanding of its toxicity which may frustrate current efforts at ridding the compound from the environment.

Differential toxicity of the UV-filters BP-3 and BP-4 in Chlamydomonas reinhardtii: A flow cytometric approach

Due to the concern about the negative effects of exposure to sunlight, UV-filters are being introduced in all kind of cosmetic formulas. Wastewater treatment plants are not able to remove and/or degrade them; consequently they find their way into rivers, lakes and oceans. These chemicals are acquiring a concerning status due to their increasingly common use and the potential risk for the environment. Benzophenone-3 (BP-3) and Benzophenone-4 (BP-4) are broad-spectrum UV-filters used for the same purpose in personal care products, insecticides and plastic bags; however, after 96 h of exposure to several concentrations of these UV-filters, the growth of C. reinhardtii was more affected by BP-3 than by BP-4, being the 96 h-EC₅₀ for growth 5 mg L^-1 and 38 mg L^-1, respectively. Based on these values Chlamydomonas reinhardtii cultures were exposed during 24 h to 2.5, 5 and 10 mg L^-1 of BP-3 and 19, 38 and 76 mg L^-1 of BP-4. A cytometric panel was carried out to evaluate the effect of sublethal concentrations of these UV-filters, thus several cytotoxicity biomarkers were analysed, including chlorophyll a fluorescence, viability, metabolic activity, oxidative stress, cytoplasmic and mitochondrial membrane potentials, and intracellular pH. BP-3 and BP-4 affect C.reinhardtii cells in a different way, showing differences for three of the examined parameters. Chlorophyll a fluorescence and mitochondrial membrane potential showed a significant increase (p < 0.05) in BP-3 and a significant decrease in BP-4, whereas viability only decreased significantly in the highest concentrations of BP-3. Regarding to the other parameters analysed, a similar pattern of cytotoxicity was observed. Growth rate, vital population and metabolic activity (esterase activity) and intracellular pH decreased significantly and cytoplasmic membrane potential and ROS levels increased significantly in cultures exposed to both pollutants.

Effect of PHRs and PCPs on Microalgal Growth, Metabolism and Microalgae-Based Bioremediation Processes: A Review

In this review, the effect of pharmaceuticals (PHRs) and personal care products (PCPs) on microalgal growth and metabolism is reported. Concentrations of various PHRs and PCPs that cause inhibition and toxicity to growths of different microalgal strains are summarized and compared. The effect of PHRs and PCPs on microalgal metabolism (oxidative stress, enzyme activity, pigments, proteins, lipids, carbohydrates, toxins), as well as on the cellular morphology, is discussed. Literature data concerning the removal of PHRs and PCPs from wastewaters by living microalgal cultures, with the emphasis on microalgal growth, are gathered and discussed. The potential of simultaneously bioremediating PHRs/PCPs-containing wastewaters and cultivating microalgae for biomass production in a single process is considered. In the light of reviewed data, the feasibility of post-bioremediation microalgal biomass is discussed in terms of its contamination, biosafety and further usage for production of value-added biomolecules (pigments, lipids, proteins) and biomass as a whole.

Demonstrating the need for chemical exposure characterisation in a microplate test system: toxicity screening of sixteen pesticides on two marine microalgae

Pesticides used in viticulture create a potential risk for the aquatic environment due to drift during application, runoff and soil leaching. The toxicity of sixteen pesticides and one metabolite were evaluated on the growth of two marine microalgae, Tisochrysis lutea and Skeletonema marinoi, in 96-h exposure assays conducted in microplates. For each substance, concentrations of stock solutions were analytically measured and abiotic assays were performed to evaluate the chemical stability of pesticides in microplates. For two chemicals, microalgae exposures were run simultaneously in microplates and culture flasks to compare EC₅₀ calculated from the two exposure systems. Results from chemical analyses demonstrated the low stability of hydrophobic pesticides (log K_OW > 3). For such chemicals, EC₅₀ values calculated using measured pesticide concentrations were two-fold lower than those first estimated using nominal concentrations. Photosystem II inhibitors were the most toxic herbicides, with EC₅₀ values below 10 μg L^-1 for diuron and around double this for isoproturon. Chlorpyrifos-methyl was the only insecticide to significantly affect the growth of T. lutea, with an EC₅₀ around 400 μg L^-1. All fungicides tested were significantly toxic to both species: strobilurins showed low overall toxicity, with EC₅₀ values around 400 μg L^-1, whereas quinoxyfen, and spiroxamine, showed high toxicity to both species, especially to T. lutea, with an EC₅₀ below 1 μg L^-1 measured for spiroxamine in culture flasks. This study highlights the need to perform chemical analyses for reliable toxicity assessment and discusses the advantages and disadvantages of using microplates as a toxicity screening tool.

Using an interpolation-based method (IDVequ) to predict the combined toxicities of hormetic ionic liquids

In the field of computational toxicology, predicting toxicological interaction or hormesis effect of a mixture from individuals is still a challenge. The two most frequently used model concentration addition (CA) and independent action (IA) also cannot solve these challenges perfectly. In this paper, we used IDV_equ (an interpolation method based on the Delaunay triangulation and Voronoi tessellation as well as the training set of direct equipartition ray design (EquRay) mixtures) to predict the toxicities of binary mixtures composed of hormetic ionic liquids (ILs). One of the purposes is to verify the predictive ability of IDV_equ. The other one is to improve the risk assessment of ILs mixtures especial hormetic ILs, because the toxicity reports of ILs mixtures are rarely reported in particular the toxicity of the hormetic ILs mixtures. Hence, we determined time-dependent toxicities of four ILs and their binary mixtures (designed by EquRay) to Vibrio qinghaiensis sp.-Q67 at first. Then, mixture toxicities were predicted and compared using the IDV_equ and CA. The results show that, the accuracy of IDV_equ is higher than the accuracy of CA. And, more important, to some mixtures out of the CA application, IDV_equ also can predict the mixture effects accurately. It showed that IDV_equ can be applied to predict the toxicity of any binary mixture regardless of the type of concentration-response curve of the components. These toxicity data provided useful information for researching the prediction of hormesis or toxicological interaction of the mixture and toxicities of ILs mixtures.

Sensitivities of seven algal species to triclosan, fluoxetine and their mixtures

Increasing release of pharmaceuticals and personal care products (PPCPs) into aquatic ecosystems is a growing environmental concern. Triclosan and fluoxetine are two widely used PPCPs and frequently detected in aquatic ecosystems. In this study, the sensitivities of 7 algal species from 4 genera to triclosan, fluoxetine and their mixture were evaluated. The results showed that the inhibitory effect on algal growth (EC₅₀-96h) of triclosan varied with 50 times differences among the 7 algal species. Chlorella ellipsoidea was the least susceptible species and Dunaliella parva was the most sensitive species to triclosan. The inhibitory effect of fluoxetine was less variable than triclosan. Slightly higher toxicity of fluoxetine than triclosan was shown in the 7 tested algal species. No consistent pattern of the effects from mixture of triclosan and fluoxetine was observed among the 7 algal species and among the 4 genera. Additive effects of the mixture occured in 4 species and antagonistic effects in the other 3 species but no synergistic effect was detected. The algal species might show some sign of phylogenetic response to triclosan, as evidenced by the wide range of differences in their sensitivity at the genus level. This study provides important data which could be beneficial for biomonitoring programs on the ecological risk (algal species diversity) of these two chemicals.

Identification of algal growth inhibitors in treated waste water using effect-directed analysis based on non-target screening techniques

Growth inhibition of freshwater microalga Pseudokirchneriella subcapitata caused by a waste water treatment plant (WWTP) effluent extract was investigated using an effect directed analysis (EDA) approach. The objective was to identify compounds responsible for the toxicity by combining state-of-the-art sampling, bioanalytical, fractionation and non-target screening techniques. Three fractionation steps of the whole extract were performed and bioactive fractions were analysed with GC (xGC)-MS and LC-HRMS. In total, 383 compounds were tentatively identified, and their toxicity was characterized using US EPA Ecotox database, open scientific literature or modelled by ECOSAR. Among the top-ranking drivers of toxicity were pesticides and their transformation products, pharmaceuticals (barbiturate derivatives and macrolide antibiotics e.g. azithromycin), industrial compounds or caffeine and its metabolites. Several of the top-ranking pesticides are no longer registered for use in plant protection products or biocides in the Czech Republic (e.g. prometryn, atrazine, acetochlor, resmethrin) and some are approved only for use in biocides (e.g. terbutryn, carbendazim, phenothrin), which indicates that their non-agricultural input into aquatic environment via WWTPs should be carefully considered. The study demonstrated a functional strategy of combining biotesting, fractionation and non-target screening techniques in the EDA study focused on the identification of algal growth inhibitors in WWTP effluent.

Analytical approaches for the determination of personal care products and evaluation of their occurrence in marine organisms

Contamination of the aquatic environment caused by multiple human activities may exert a negative impact on all living organisms. Several contaminants of emerging concern such as personal care products (PCPs) are continuously released into the aquatic environment where they are biologically active and persistent. This work reviews the current knowledge, provided by papers published after 2010 and indexed by SciFinder, Scopus, and Google search engines, about the determination and occurrence of PCPs in marine biota. Analytical methodologies have been critically reviewed, emphasizing the importance of green and high-throughput approaches and focusing the discussion on the complexity of the solute-matrix interaction in the extraction step, as well as the matrix effect in the instrumental determination. Finally, the worldwide distribution of PCPs is surveyed, taking into account the concentrations found in the same organism in different marine environments. Differences among various world areas have been highlighted, evidencing some critical aspects from an environmental point of view.

Long-term algal toxicity of oxidant treated ballast water

National and international regulations require that ships' ballast water is treated to minimize the risk of introducing potentially invasive species. A common approach employed by commercial ballast water management systems is chlorination. This study presents the algal toxicity findings for three chlorination-based BWMS and their implications to environmental safety of port waters receiving treated ballast water from ships. Discharged treated ballast water from all three BWMS was toxic to algae with IC25s (25% growth inhibition) ranging from 9.9% to 17.9%, despite having total residual oxidant concentrations below 0.02 mg/l, based on Whole Effluent Toxicity assays. When held at 4 °C, some of the ballast water samples continued to exhibit toxic effects with no observed effect concentrations as low as 18% after a 134 day holding time. Thirteen individual disinfection by-products were measured above the detected limit at the time of discharge. No correlation between DBPs and algal toxicity was observed.

Joint effects of nine antidepressants on Raphidocelis subcapitata and Skeletonema marinoi: A matter of amine functional groups

Antidepressants are among the most prescribed pharmaceuticals throughout the world. Their presence has already been detected in several aquatic ecosystems worldwide and their effects on non-target organisms justify the growing concern of both the public and regulatory authorities. These emerging pollutants do not occur as isolated compounds but rather as multi-component mixtures, which may lead to increased adverse effects compared to individual compounds. Freshwater and marine algae seem particularly sensitive to pharmaceuticals, including antidepressants. Studies assessing the toxicity of antidepressant mixture to algae focused mainly on binary mixtures of selective serotonin reuptake inhibitors. In the present experiment, the freshwater algae Raphidocelis subcapitata (formerly known as Pseudokirchneriella subcapitata) and the marine diatom Skeletonema marinoi were exposed to equitoxic mixtures of 9 antidepressants (fluvoxamine, fluoxetine, sertraline, duloxetine, venlafaxine, clomipramine, amitriptyline, and citalopram) at different concentrations. The growth inhibition was measured. Results showed that the toxicity of this mixture was higher than the effects of each individual component, highlighting simple additivity or synergistic effects, whereas tested concentrations were below the 10% inhibition concentration (IC₁₀) of each compound. Moreover, the QSAR analysis highlighted that antidepressants would act through narcosis (non-specific mode of action) towards the two species of algae. However, more specific effects can be observed by differentiating compounds with a primary/secondary amine from those with a tertiary amine. These mixture effects on algal species have to be assessed, especially since any impacts on phytoplankton could ultimately impact higher trophic levels (less food, secondary poisoning).

Evaluating the Joint Toxicity of Two Benzophenone-Type UV Filters on the Green Alga Chlamydomonas reinhardtii with Response Surface Methodology

The widespread occurrence of benzophenone-type ultraviolet (UV) filter has raised the public concerns over the ecotoxicological effects of these chemicals. The present study assessed the joint toxicity of two representative benzophenones, benzophenone-1 (BP-1) and benzophenone-3 (BP-3), on the green alga Chlamydomonas reinhardtii using response surface methodologies (RSM). Specific growth rate and photosynthetic pigments were used as endpoints to evaluate the toxic effects. Generally, exposure to the combined BP-1 and BP-3 negatively affected cell growth and pigments production, with higher inhibitions at higher exposure concentrations. The simultaneous reduction in growth rate and pigments contents indicated that BP-1 and BP-3 regulated the growth of the tested alga by affecting the photosynthesis process. Results also showed that second order polynomial regression models fitted well with experimental results for all endpoints. The obtained regression models further indicated that the effects of the combination stemmed significantly from the linear concentration of BP-1 and BP-3. The overall results demonstrated that RSM could be a useful tool in ecotoxicological studies.

Effects of benzophenone-3 on the green alga Chlamydomonas reinhardtii and the cyanobacterium Microcystis aeruginosa

Effects of benzophenone-3 (BP-3) on the green alga, Chlamydomonas reinhardtii, and the cyanobacterium, Microcystis aeruginosa, were investigated. The tested organisms were exposed to environmental levels of BP-3 for 10 days, at nominal concentrations from 0.01 to 5000μgL^-1. Specific growth rate and photosynthetic pigments were employed to evaluate the toxic responses. The two tested algae had distinct toxic responses towards BP-3 stress, with the green alga C. reinhardtii being more sensitive than the cyanobacterium M. aeriginosa, based on EC₂₀ and EC₅₀ values. Uptake of BP-3 from the medium occurred in both species, with M. aeruginosa showing greater overall uptake (27.2-77.4%) compared to C. reinhardtii (1.1-58.4%). The effects of BP-3 on C. reinhardtii were variable at concentrations lower than 100μgL^-1. At higher concentrations, the specific growth rate of C. reinhardtii decreased following a reduction in chlorophyll a (chl-a) content. Further experiments showed that BP-3 regulated the growth of C. reinhardtii by affecting the production of chl-a, chlorophyll b and carotenoids. In M. aeruginosa, specific growth rate was only moderately affected by BP-3. Additionally, the production of chl-a was significantly inhibited over the different exposure concentrations, while the production of carotenoids was stimulated. These results indicate a potential detrimental effect on prokaryotes and eukaryotes and that the mechanism of action varies with species.

Photolysis of pharmaceuticals and personal care products in the marine environment under simulated sunlight conditions: irradiation and identification

The photochemical fate of 16 pharmaceuticals and personal care products (PPCPs) found in the environment has been studied under controlled laboratory conditions applying a sunlight simulator. Aqueous samples containing PPCPs at environmentally relevant concentrations were extracted by solid-phase extraction (SPE) after irradiation. The exposed extracts were subsequently analysed by liquid chromatography combined with triple quadrupole mass spectrometry (HPLC-MS/MS) for studying the kinetics of photolytic transformations. Almost all exposed PPCPs appeared to react with a half-life time (τ _1/2) of less than 30 min. For ranitidine, sulfamethoxazole, diclofenac, warfarin, sulfamethoxazole and ciprofloxacin, τ_1/2 was found to be even less than 5 min. The structures of major photolysis products were determined using quadrupole-time-of-flight mass spectrometry (QToF) and spectroscopic data reported in the literature. For diclofenac, the transformation products carbazol-1-yl-acidic acid and 8-chloro-9H-carbazol-1-yl-acetic acid were identified based on the mass/charge ratio of protonated ions and their fragmentation pattern in negative electrospray ionization (ESI^--QTOF). Irradiation of carbamazepine resulted in three known products: acridine, carbamazepine-10,11-epoxide, and 10,11-dihydro-10,11-dihydroxy-carbamazepine, whereas acetaminophen was photolytically transformed to 1-(2-amino-5 hydroxyphenyl) ethenone. These photochemical products were subsequently identified in seawater or fish samples collected at sites exposed to wastewater effluents on the Saudi Arabian coast of the Red Sea.

Single- and mixture toxicity of three organic UV-filters, ethylhexyl methoxycinnamate, octocrylene, and avobenzone on Daphnia magna

In freshwater environments, aquatic organisms are generally exposed to mixtures of various chemical substances. In this study, we tested the toxicity of three organic UV-filters (ethylhexyl methoxycinnamate, octocrylene, and avobenzone) to Daphnia magna in order to evaluate the combined toxicity of these substances when in they occur in a mixture. The values of effective concentrations (ECx) for each UV-filter were calculated by concentration-response curves; concentration-combinations of three different UV-filters in a mixture were determined by the fraction of components based on EC₂₅ values predicted by concentration addition (CA) model. The interaction between the UV-filters were also assessed by model deviation ratio (MDR) using observed and predicted toxicity values obtained from mixture-exposure tests and CA model. The results from this study indicated that observed ECx_mix (e.g., EC_10mix, EC_25mix, or EC_50mix) values obtained from mixture-exposure tests were higher than predicted ECx_mix (e.g., EC_10mix, EC_25mix, or EC_50mix) values calculated by CA model. MDR values were also less than a factor of 1.0 in a mixtures of three different UV-filters. Based on these results, we suggest for the first time a reduction of toxic effects in the mixtures of three UV-filters, caused by antagonistic action of the components. Our findings from this study will provide important information for hazard or risk assessment of organic UV-filters, when they existed together in the aquatic environment. To better understand the mixture toxicity and the interaction of components in a mixture, further studies for various combinations of mixture components are also required.

Polymyxin B sulfate inducing time-dependent antagonism of the mixtures of pesticide, ionic liquids, and antibiotics to Vibrio qinghaiensis sp.-Q67

In the real environment, organisms are simultaneously exposed to different types of chemicals.

Single and mixture toxicity of pharmaceuticals and chlorophenols to freshwater algae Chlorella vulgaris

Organisms in the aquatic environment are exposed to a variety of substances of numerous chemical classes. The unintentional co-occurrence of pharmaceuticals and other contaminants of emerging concern may pose risk to non-target organisms. In this study, individual and binary mixture toxicity experiments of selected pharmaceuticals (ibuprofen and ciprofloxacin) and chlorophenols (2.4-dichlorophenol (2,4-DCP) and 3-chlorophenol (3-CP)) have been performed with freshwater algae Chlorella vulgaris. All experiments have been carried out according to the 96-h algal growth inhibition test OECD No. 201. Binary mixture tests were conducted using proportions of the respective IC50s in terms of toxic unit (TU). The mixture concentration-response curve was compared to predicted effects based on both the concentration addition (CA) and the independent action (IA) model. Additionally, the Combination Index (CI)-isobologram equation method was used to assess toxicological interactions of the binary mixtures. All substances individually tested had a significant effect on C. vulgaris population density and revealed IC50 values <100mgL(-1) after exposure period of 96-h. The toxic ranking of these four compounds to C. vulgaris was 2,4-DCP>ciprofloxacin>3-CP>ibuprofen. Generally, it can be concluded from this study that toxic mixture effects of all tested chemicals to C. vulgaris are higher than the individual effect of each mixture component. It could be demonstrated that IC50 values of the tested mixtures predominately lead to additive effects. The CA model is appropriate to estimate mixture toxicity, while the IA model tends to underestimate the joint effect. The CI-isobologram equation method predicted the mixtures accurately and elicited synergism at low effect levels for the majority of tested combinations.

Shotgun proteomics to unravel marine mussel (Mytilus edulis) response to long-term exposure to low salinity and propranolol in a Baltic Sea microcosm

Pharmaceuticals, among them the β-adrenoceptor blocker propranolol, are an important group of environmental contaminants reported in European waters. Laboratory exposure to pharmaceuticals on marine species has been performed without considering the input of the ecosystem flow. To unravel the ecosystem response to long-term exposure to propranolol we have performed long-term exposure to propranolol and low salinity in microcosms. We applied shotgun proteomic analysis to gills of Mytilus edulis from those Baltic Sea microcosms and identified 2071 proteins with a proteogenomic strategy. The proteome profiling patterns from the 587 highly reproductive proteins among groups define salinity as a key factor in the mussel's response to propranolol. Exposure at low salinity drives molecular mechanisms of adaptation based on a decrease in the abundance of several cytoskeletal proteins, signalling and intracellular membrane trafficking pathway combined with a response towards the maintenance of transcription and translation. The exposure to propranolol combined with low salinity modulates the expression of structural proteins including cilia functions and decreases the expression of membrane protein transporters. This study reinforces the environment concerns of the impact of low salinity in combination with anthropogenic pollutants and anticipates critical physiological conditions for the survival of the blue mussel in the northern areas.

BIOLOGICAL SIGNIFICANCE

Applying shotgun proteomic analysis to M. edulis gills samples from a long-term microcosm exposure to propranolol and following a proteogenomic identification strategy, we have identified 2071 proteins. The proteomic analysis unrevealed which molecular mechanisms drive the adaptation to low salinity stress and how salinity modulates the effects of exposure to propranolol. These results reinforce the idea of the impact of low salinity in combination with anthropogenic pollutants and anticipate critical physiological condition.

Occurrence, ecotoxicological effects and risk assessment of antihypertensive pharmaceutical residues in the aquatic environment--A review

This study presents a review of the investigated antihypertensives in different aquatic compartments. It aims to compare these data with those regarding ecotoxicity effects in order to find out ecotoxicological data gaps for these pharmaceuticals and to point out the need for future studies. In addition, part of this article is dedicated to the risk assessment of the parent compounds atenolol, metoprolol, propranolol and verapamil, which are of great environmental concern in terms of contamination levels and for which there are sufficient ecotoxicological data available. 79 articles were retrieved presenting quantization data for 34 different antihypertensives and/or their metabolites. Only 43 articles were found regarding acute and chronic ecotoxicological effects of antihypertensive drugs. The results indicated that the beta-blockers atenolol, metoprolol and propranolol are the antihypertensives most frequently detected in the aquatic environment. They are also the drugs which reached the highest maximum concentrations in surface waters in the data reported in the literature. The highest percentages of ecotoxicity data regarding antihypertensives were also related to these beta-blockers. On the other hand, there is clearly a lack of ecotoxicity data, especially the chronic ones, regarding other antihypertensives. The environmental risk assessment (ERA) showed that all three of the evaluated beta-blockers can pose a potential long-term risk for non-target organisms of both fresh and marine water species. However, more meaningful ecotoxicity data for antihypertensives, including saltwater species, are required to refine and enlarge these results. Additional studies focusing on potential interactions between pharmaceutical mixtures, including antihypertensives, are also an urgent need.

Selective serotonin reuptake inhibitors and β-blocker transformation products may not pose a significant risk of toxicity to aquatic organisms in wastewater effluent-dominated receiving waters

A probabilistic ecological risk assessment was conducted for the transformation products (TPs) of 3 β-blockers (atenolol, metoprolol, and propranolol) and 5 selective serotonin reuptake inhibitors (SSRIs; citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline) to assess potential threats to aquatic organisms in effluent-dominated surface waters. To this end, the pharmacokinetic literature, the University of Minnesota's Biocatalysis/Biodegradation Database Pathway Prediction System aerobic microbial degradation software, and photolysis literature pertaining to β-blockers and SSRIs were used to determine their most likely TPs formed via human metabolism, aerobic biodegradation, and photolysis, respectively. Monitoring data from North American and European surface waters receiving human wastewater inputs were the basis of the exposure characterizations of the parent compounds and the TPs, where available. In most cases, where monitoring data for TPs did not exist, we assumed a conservative 1:1 parent-to-TP production ratio (i.e., 100% of parent converted). The US Environmental Protection Agency (USEPA)'s EPISuite and ECOSAR v1.11 software were used to estimate acute and chronic toxicities to aquatic organisms. Hazard quotients, which were calculated using the 95(th) percentile of the exposure distributions, ranged from 10(-11) to 10(-3) (i.e., all significantly less than 1). Based on these results, the TPs of interest would be expected to pose little to no environmental risk in surface waters receiving wastewater inputs. Overall, we recommend developing analytical methods that can isolate and quantify human metabolites and TPs at environmentally relevant concentrations to confirm these predictions. Further, we recommend identifying the major species of TPs from classes of pharmaceuticals that could elicit toxic effects via specific modes of action (e.g., norfluoxetine via the serotonin 5-hydroxytryptamine [5-HT]1A receptors) and conducting aquatic toxicity tests to confirm these findings. To our knowledge, this is the first quantitative probabilistic ecotoxicological assessment of all of the predicted and probable TPs of these pharmaceuticals, and our approach provides a framework for future such studies with other compound classes as data become available.

Ecotoxicological evaluation of propranolol hydrochloride and losartan potassium to Lemna minor L. (1753) individually and in binary mixtures

Antihypertensive pharmaceuticals, including the beta-blockers, are one of the most detected therapeutic classes in the environment. The ecotoxicity of propranolol hydrochloride and losartan potassium was evaluated, both individually and combined in a binary mixture, by using the Lemna minor growth inhibition test. The endpoints evaluated in the single-pharmaceutical tests were frond number, total frond area and fresh weight. For the evaluation of the mixture toxicity, the selected endpoint was frond number. Water quality criteria values (WQC) were derived for the protection of freshwater and saltwater pelagic communities regarding the effects induced by propranolol and losartan using ecotoxicological data from the literature, including our data. The risks associated with both pharmaceutical effects on non-target organisms were quantified through the measured environmental concentration (MEC)/predicted-no-effect concentration (PNEC) ratios. For propranolol, the total frond area was the most sensitive endpoint (EC50 = 77.3 mg L(-1)), while for losartan there was no statistically significant difference between the endpoints. Losartan is only slightly more toxic than propranolol. Both concentration addition and independent action models overestimated the mixture toxicity of the pharmaceuticals at all the effect concentration levels evaluated. The joint action of both pharmaceuticals showed an antagonistic interaction to L. minor. Derived WQC assumed lower values for propranolol than for losartan. The MEC/PNEC ratios showed that propranolol may pose a risk for the most sensitive aquatic species, while acceptable risks posed by losartan were estimated for most of aquatic matrices. To the authors knowledge these are the first data about losartan toxicity for L. minor.

Occurrence and fate of select psychoactive pharmaceuticals and antihypertensives in two wastewater treatment plants in New York State, USA

The fates of psychoactive pharmaceuticals, including two antischizophrenics, six sedative-hypnotic-anxiolytics, four antidepressants, four antihypertensives, and their select metabolites, were determined in two wastewater treatment plants (WWTPs) in the Albany area of New York. All target psychoactive pharmaceuticals and their metabolites were found at a mean concentration that ranged from 0.98 (quetiapine) to 1220 ng/L (atenolol) in wastewater and from 0.26 (lorazepam) to 1490 ng/g dry weight (sertraline) in sludge. In this study, the fraction of psychoactive pharmaceuticals that was sorbed to suspended particulate matter (SPM) was calculated for the first time. Over 50% of the total mass of aripiprazole, norquetiapine, norsertraline, citalopram, desmethyl citalopram, propranolol, verapamil, and norverapamil was found sorbed to SPM in the influent. The mass loadings, i.e., influx, of target psychoactive pharmaceuticals in WWTPs ranged from 0.91 (diazepam) to 347 mg/d/1000 inhabitants (atenolol), whereas the environmental emissions ranged from 0.01 (dehydro-aripiprazole) to 316 mg/d/1000 inhabitants (atenolol). The highest calculated removal efficiencies were found for antischizophrenics (quetiapine=88%; aripiprazole=71%). However, the removal of some psychoactive pharmaceuticals through adsorption onto sludge was minimal (<1% of the initial mass load), which suggests that bio-degradation and/or chemical-transformation are the dominant mechanisms of removal of these pharmaceuticals in WWTPs.

A 3-year study on occurrence of emerging contaminants in an urban stream of São Paulo State of Southeast Brazil

This manuscript reports a 3-year study on occurrence of pharmaceuticals, hormones, and triclosan in surface waters of a central urban region of São Paulo State of Southeast Brazil (the Monjolinho River in São Carlos). Water samples collected once at every 2 months were pre-concentrated by solid-phase extraction (SPE) and analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The most frequently detected compounds in higher concentrations were caffeine, paracetamol, and atenolol (maximum concentrations 129,585, 30,421, and 8199 ng L(-1), respectively), while hormones estrone and 17-β-estradiol were the least detected, in levels up to 14.8 ng L(-1). There was an increasing trend in concentrations of most of the compounds along the river course, especially downstream of the river where there is discharge of both wastewater treatment plant effluent and raw sewage from a particular region of São Carlos city. Concentrations of contaminants were higher during dry periods as a result of decline in the water levels. Decrease in concentrations near the river mouth occurred to different extents for each compound. It was high for caffeine and atenolol, but was very low for carbamazepine and diclofenac. The present study reports the first data about the occurrence of some major emerging contaminants in the Monjolinho River. Besides its regional significance, this work may assist in composing a dataset for water contamination diagnosis focusing on emerging contaminants, both in the Brazilian as well as in the Global studies related to aquatic ecosystems. Such datasets can be helpful for making future public policies on water quality, since these compounds are not yet legally regulated.

The synergistic toxicity of the multiple chemical mixtures: implications for risk assessment in the terrestrial environment

The combined toxicity of five insecticides (chlorpyrifos, avermectin, imidacloprid, λ-cyhalothrin, and phoxim), two herbicides (atrazine and butachlor) and a heavy metal (cadmium) has been examined with the earthworm acute toxicity test. Toxicological interactions of these chemicals in four, five, six, seven, and eight-component mixtures were studied using the combination-index (CI) equation method. In four-component and five-component mixtures, the synergistic effects predominated at lower effect levels, while the patterns of interactions found in six, seven, and eight-component mixtures displayed synergism. The λ-CY+IMI+BUT+ATR+CPF+PHO combination displayed the most strongly synergistic interaction, with CI values ranging from 0.09 to 0.15. The nature of the interaction changes with the effect level and the relevance of synergistic effects increase with the complexity of the mixture. The CI method was compared with the classical models of concentration addition (CA) and independent action (IA) and we found that the CI method could accurately predict the combined toxicity. The predicted synergism resulted from co-existence of the pesticides and the heavy metal especially at low effect levels may have important implications in risk assessment for the real terrestrial environment.