Ecotoxicological and genotoxic evaluation of Buenos Aires city (Argentina) hospital wastewater

Review of hospital effluents: special emphasis on characterization, impact, and treatment of pollutants and antibiotic resistance

Health care institutions generate large volumes of liquid effluents from specific activities related to healthcare, analysis, and research. Their direct discharge into the environment has various negative effects on aquatic environments and human health, due to their high organic matter charges and the presence of various emerging contaminants such as disinfectants, drugs, bacteria, viruses, and parasites. Moreover, hospital effluents, by carrying antibiotics, contribute to the development of antibiotic-resistant microorganisms in the environment. This resistance has become a global issue that manifests itself variously in different countries, causing the transmission of different infections. In this respect, an effort is provided to protect water resources by current treatment methods that imply physical-chemical processes such as adsorption and advanced oxidation processes, biological processes such as activated sludge and membrane bioreactors and other hybrid techniques. The purpose of this review is to improve the knowledge on the composition and impact of hospital wastewater on man and the environment, highlighting the different treatment techniques appropriate to this type of disposal before discharge into the environment.

Antibiotic Toxicity Isolated and as Binary Mixture to Freshwater Algae Raphidocelis subcapitata: Growth Inhibition, Prediction Model, and Environmental Risk Assessment

Antibiotics in aqueous environments can have extremely adverse effects on non-targeted organisms. However, many research projects have only focused on the toxicological evaluation of individual antibiotics in various environments. In the present work, individual and binary mixture toxicity experiments have been conducted with the model organism Raphidocelis subcapitata (R. subcapitata), and a mixture concentration-response curve was established and contrasted with the estimated effects on the basis of both the concentration addition (CA) and the independent action (IA) models. In addition, different risk assessment methods were used and compared to evaluate the environmental risk of binary mixtures. The toxic ranking of the selected antibiotics to R. subcapitata was erythromycin (ERY) > sulfamethoxazole (SMX) > sulfamethazine (SMZ). In general, the conclusion of this study is that the adverse effects of binary mixtures are higher than the individual antibiotics. The CA model and RQSTU are more suitable for toxicity prediction and risk assessment of binary mixtures. This study reveals the potential ecological risks that antibiotics and their mixtures may pose to water ecosystems, thus providing scientific information for environmental quality regulation.

Brain damage induced by contaminants released in a hospital from Mexico: Evaluation of swimming behavior, oxidative stress, and acetylcholinesterase in zebrafish (Danio rerio)

Several studies have indicated that hospital effluents can produce genotoxic and mutagenic effects, cytotoxicity, hematological and histological alterations, embryotoxicity, and oxidative stress in diverse water organisms, but research on the neurotoxic effects hospital wastewater materials can generate in fish is still scarce. To fill the above-described knowledge gap, this study aimed to determine whether the exposure of adult zebrafish (Danio rerio) to several proportions (0.1%, 2.5%, 3.5%) of a hospital effluent can disrupt behavior or impair redox status and acetylcholinesterase content in the brain. After 96 h of exposure to the effluent, we observed a decrease in total distance traveled and an increase in frozen time compared to the control group. Moreover, we also observed a significant increase in the levels of reactive oxygen species in the brains of the fish, especially in hydroperoxide and protein carbonyl content, relative to the control group. Our results also demonstrated that hospital effluents significantly inhibited the activity of the AChE enzyme in the brains of the fish. Our Pearson correlation demonstrated that the response to acetylcholinesterase at the lowest proportions (0.1% and 2.5%) is positively related to the oxidative stress response and the behavioral changes observed. The cohort of our studies demonstrated that the exposure of adult zebrafish to a hospital effluent induced oxidative stress and decreased acetylcholinesterase activity in the brain of these freshwater organisms, which can lead to alterations in their behavior.

An assessment of hospital wastewater and biomedical waste generation, existing legislations, risk assessment, treatment processes, and scenario during COVID-19

Hospitals release significant quantities of wastewater (HWW) and biomedical waste (BMW), which hosts a wide range of contaminants that can adversely affect the environment if left untreated. The COVID-19 outbreak has further increased hospital waste generation over the past two years. In this context, a thorough literature study was carried out to reveal the negative implications of untreated hospital waste and delineate the proper ways to handle them. Conventional treatment methods can remove only 50%-70% of the emerging contaminants (ECs) present in the HWW. Still, many countries have not implemented suitable treatment methods to treat the HWW in-situ. This review presents an overview of worldwide HWW generation, regulations, and guidelines on HWW management and highlights the various treatment techniques for efficiently removing ECs from HWW. When combined with advanced oxidation processes, biological or physical treatment processes could remove around 90% of ECs. Analgesics were found to be more easily removed than antibiotics, β-blockers, and X-ray contrast media. The different environmental implications of BMW have also been highlighted. Mishandling of BMW can spread infections, deadly diseases, and hazardous waste into the environment. Hence, the different steps associated with collection to final disposal of BMW have been delineated to minimize the associated health risks. The paper circumscribes the multiple aspects of efficient hospital waste management and may be instrumental during the COVID-19 pandemic when the waste generation from all hospitals worldwide has increased significantly.

Occurrence, detection and ecotoxicity studies of selected pharmaceuticals in aqueous ecosystems- a systematic appraisal

Pharmaceutical compounds (PCs) have globally emerged as a significant group of environmental contaminants due to the constant detection of their residues in the environment. The main scope of this review is to fill the void of information on the knowledge on the African occurrence of selected PCs in environmental matrices in comparison with those outside Africa and their respective toxic actions on both aquatic and non-aquatic biota through ecotoxicity bioassays. To achieve this objective, the study focused on commonly used and detected pharmaceutical drugs (residues). Based on the conducted literature survey, Africa has the highest levels of ciprofloxacin, sulfamethoxazole, lamivudine, acetaminophen, and diclofenac while Europe has the lowest of all these PC residues in her physical environments. For ecotoxicity bioassays, the few data available are mostly on individual groups of pharmaceuticals whereas there is sparsely available data on their combined forms.

Removal of two cytostatic drugs: bleomycin and vincristine by white-rot fungi - a sorption study

PURPOSE

Cytostatic drugs cannot be easily removed by conventional sewage treatment plants, resulting in their ultimate release into aquatic systems where they become a threat. Thus, new technologies which can be used to eliminate these drugs more effectively before they enter the environment are increasingly important. Fungal treatment of wastewaters is a promising and environmentally friendly technology for pharmaceutical remediation. The aim of this work is to examine the biosorption of two cytostatics, bleomycin and vincristine, in the aqueous solution by fungal biomass.

METHODS

Five white-rot fungi were used in this study: Fomes fomentarius (CB13), Hypholoma fasciculare (CB15), Phyllotopsis nidulans (CB14), Pleurotus ostreatus (BWPH), and Trametes versicolor (CB8). Tests were conducted on different types of biomass (alive and dead - autoclaved) and in various physico-chemical conditions: varied drug concentrations (5, 10 and 15 mg/L), temperatures (from 15.4 to 29.6 °C), and pH (from 3.2 to 8.8).

RESULTS

The results showed that among alive biomass, T. versicolor (CB8) had the greatest sorption ability for bleomycin and P. nidulans (CB14) worked best for vincristine. The tested sorption process could be described by a pseudo-second order kinetics model. Sorption equilibrium studies demonstrated that for bleomycin Redlich-Peterson, while for vincristine Langmuir model fitted best. The thermodynamic studies showed that the sorption process was endothermic chemisorption for bleomycin, and exothermic physisorption for vincristine. For both drugs the sorption ability increased with an increase of the pH value.

CONCLUSION

The biosorption on fungal biomass is a favorable alternative to conventional wastewater treatment processes for anticancer drug removal.

Evaluation of the raw water quality: physicochemical and toxicological approaches

Environmental degradation has increased, mainly as a result of anthropogenic effects arising from population, industrial and agricultural growth. Water pollution is a problem that affects health, safety and welfare of the whole biota which shares the same environment. In Goiânia and metropolitan region, the main water body is the Meia Ponte River that is used for the abstraction of water, disposal of treated wastewater and effluents. In addition, this river receives wastewater from urban and rural areas. The aim in this present study was to evaluate the quality of raw water by some physical, chemical and toxicological tests. The physicochemical results found high levels of turbidity, conductivity, aluminum, phosphorus and metal iron, manganese, copper and lithium when compared to the standards of the Brazilian legislation. The values found of toxicity demonstrated a high degree of cytotoxicity and genotoxicity. Therefore, it was concluded that the Meia Ponte River has been undergoing constant environmental degradation, causing the poor quality of its waters. Thus, measures for the prevention and recovery should be adopted for the maintenance of the Meia Ponte River.

Environmental Transformation of Pharmaceutical Formulations: A Scientific Review

Environmental pollution caused by pharmaceuticals and their transformation products (TPs) has become an increasingly important concern, due to the increased use of pharmaceutical formulations exposed to environmental change. Considerable concerns have been raised regarding potential toxic effects of the transformation products of pharmaceutical formulations on human health. Environmental risk assessments are mostly based on one active component, which causes different ecotoxicological effects, albeit the particular component is present in the environment as a part of a multicomponent mixture with different pharmaceuticals and excipients. The purpose of this review was to present the insight and new knowledge recently obtained by studies on the risk of pharmaceutical formulations, including all contained excipients, pharmaceuticals, and their transformation products exposed to the environment. Numerous studies have shown that the level of pharmaceuticals in the environment is below toxic concentration; however, long exposure to very low concentrations can still lead to harmful concentrations in biota. Accordingly, the findings of this study are expected to highlight the existing issues of the effect of pharmaceutical formulations to the environment, including TPs, and help to determine future research directions towards accumulating the data and improving ecological risk assessment.

Alterations to embryonic development and teratogenic effects induced by a hospital effluent on Cyprinus carpio oocytes

Hospital functioning generates a great quantity of contaminants, among which organic materials, heavy metals, and diverse pharmaceuticals are noteworthy that can affect organisms if they are not properly removed from the effluents. The hospital effluent evaluated in the present study came from IMSS (Instituto Mexicano del Seguro Social) Clinic 221 in downtown Toluca, State of Mexico, a secondary care facility. The contaminants identified in hospitals have been associated with deleterious effects on aquatic organisms; however, it is necessary to continue with more studies in order to be able to regulate the production of said contaminants which are generally dumped into the city sewage system. The present study had the purpose of evaluating the alterations to embryonic development and teratogenic effects on oocytes Cyprinus carpio after exposure to different proportions of hospital effluent. For said purpose, the physicochemical properties of the effluent were determined. Concentrations of the main microcontaminants were also determined. An embryolethality study out and the determination of the main alterations to embryonic development and teratogenic effects produced, due to exposure of C. carpio at different proportions of the effluent, were carried out. The results showed that the physicochemical properties were within the values permitted by Mexican regulation; however, the presence of contaminants such as NaClO, metals, anti-biotics, anti-diabetics, non-steroidal anti-inflammatory drugs, hormones and beta-blockers, was detected. Lethal concentration 50 was 5.65% and the effective concentration for malformations was 3.85%, with a teratogenic index of 1.46. The main teratogenic alterations were yolk deformation, scoliosis, modified chorda structure, tail malformation, fin deformity and mouth hyperplasia. A high rate of hatching delay was observed. The results suggest that the hospital effluent under study is capable of inducing embryotoxicity and teratogenicity in oocytes of C. carpio.

Exposure to effluent from pharmaceutical industry induced cytogenotoxicity, hematological and histopathological alterations in Clarias gariepinus (Burchell, 1822)

Pharmaceutical effluents contain toxic xenobiotics capable of contaminating aquatic environments. Untreated effluents are illegally discharged into aquatic environment in most developing countries. Pharmaceutical effluent induced alterations in biomarkers of genetic and systemic damage on rodents. However, information is relatively scarce on the possible cytogenotoxicity and systemic toxicity of this effluent on aquatic vertebrates. The study herein assessed the cytogenotoxic, hematological and histopathological alterations induced by pharmaceutical effluent in Clarias gariepinus. 96 h acute toxicity of the effluent was determined after C. gariepinus was exposed to six different concentrations (10 - 60 %) of the effluent. Subsequently, fish was exposed to sub-lethal concentrations (2.18 - 17.41 %) obtained from the 96 h LC50 for 7 and 14 days after which micronucleus (MN) and nuclear abnormalities (NAs) in peripheral erythrocytes were assessed as cytogenotoxic biomarkers, alterations in hematological indices and histopathological lesions were also examined. Fish, concurrently exposed to dechlorinated tap water and benzene (0.01 mL/L), served as negative and positive controls respectively. The derived 96 h LC50 of 17.41 % which was 1.89 times more toxic than the 24 h LC50 (32.95 %) showed that the effluent induced concentration-dependent mortality according to exposure duration. The effluent caused significant (p<0.05) time-dependent increase in the frequency of MN and abnormal nuclear erythrocytes compared to the negative control. Also, there was decrease in total erythrocyte counts, hemoglobin and hematocrit concentrations and increase in leucocyte and lymphocyte counts. The effluent induced pathological lesions on gills, liver and kidneys of treated fish. Higher physicochemical parameters than standard permissible limits in the effluent are capable of inducing genomic instability and systemic damage in fish. Pharmaceutical effluent can increase micropollutants in aquatic environmental and health risks to aquatic biota. There is need to promulgate stringent laws against illegal discharge of effluents into aquatic environment.

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.

Dietary ascorbic acid reduced micronucleus and nuclear abnormalities in Clarias gariepinus (Burchell 1822) exposed to hospital effluent

Hospital effluents contain myriad of mutagens and genotoxins capable of increasing DNA damage in aquatic biota. African mudfish, Clarias gariepinus, are exposed to genotoxins when cultured in swamps and derelict water bodies often contaminated by effluents. Moreover, its DNA is susceptible to xenobiotic-induced lesions since it lacks L-gulonolactone oxidase and hence cannot synthesize L-ascorbic acid. This study investigated 96-h acute toxicity and protective effects of dietary ascorbic acid (AA) against micronucleus (MN) and abnormal nuclear (NAs) formation in C. gariepinus exposed to sub-lethal concentrations of hospital effluent. Six concentrations (0.5-3.0%) of the effluent were selected to determine the 96-h acute toxicity of the effluent in C. gariepinus, after range finding test. Fish were exposed to sub-lethal concentrations (0.08-1.30%) of the 96 h LC₅₀. Two other groups were exposed to the 96 h LC₅₀ (1.30%) of the effluent +50 and +100 mg/kg of dietary ascorbic for 7 days, and MN and NAs assessed in peripheral erythrocytes. The 96 h LC₅₀ (1.30%) was 1.18 times more toxic than the 24 h LC₅₀ (1.54%), indicating that the toxicity of the effluent increased with exposure duration. MN, nuclear bud, enucleated, fragmented nucleus (apoptosis), and necrotic erythrocytes significantly increase in effluent treated fish. Dietary AA reduced MN from 6.35-fold (1.30% treated group) to 3.72-fold (1.30% + 50 mg AA) and 3.54-fold (1.30% + 100 mg AA). Also, AA reduced total NAs from 2.26-fold (1.30%) to 1.40-fold (1.30% + 50 mg AA) and 1.06-fold (1.30% + 100 mg AA) compared to the control. Heavy metals and physicochemical parameters analyzed in the tested effluent possibly induced the mortality and cytogenotoxicity in C. gariepinus, and this was ameliorated by dietary AA.

Occurrence of heavy metals and contaminants on the surface of adjacent rivers

Water is fundamental to the survival of living beings. It registers every impact and can function as an indicator of environmental stressors. Our objective in the current study was to assess the sanitary conditions of the waters in the Açude, Maria Lucinda and Santa Rosa streams. This was done by checking pH, running quantitative analyses of heavy metals and testing for total coliforms. The effect of ultraviolet (UV) rays on samples positive for coliforms was evaluated. The average pH of the streams ranged between 4 and 7 and changed between drought and rainy season conditions. Chromium and nickel values were above those permitted by the Brazilian National Council on the Environment, CONAMA. In the dry season, zinc values were above those established by CONAMA for waterbodies of Classes 1 and 2. Thermotolerant coliforms were present in all samples collected and above permitted values. After exposing the bacteria to UV light, it was noted that UV irradiation was unable to decrease the bacteria count. Ninety residents who use stream water were interviewed: 24% of interviewees said they use the waters of the Açude and Mary Lucinda streams and along the Santa Rosa stream, 95% of inhabitants said they use the water.

Toxicity and genotoxicity assessment in sediments from the Matanza-Riachuelo river basin (Argentina) under the influence of heavy metals and organic contaminants

The aim of this study was to investigate the parameters of chemical extraction associated with the detection of toxicity and genotoxicity in sediment sample extracts. Quantitative analysis of metals and polycyclic aromatic hydrocarbons (PAHs), together with a battery of four bioassays, was performed in order to evaluate the extraction efficiency of inorganic and organic toxicants. The extracts were carried out using two inorganic solvents, two organic solvents and two extraction methodologies, making a total of five extracts. Two toxicity tests, the algal growth inhibition of Pseudokirchneriella subcapitata and the root elongation inhibition of Lactuca sativa, and two genotoxicity tests, the analysis of revertants of Salmonella typhimurium and the analysis of micronuclei and chromosomal aberrations in Allium cepa, were performed. According to the chemical analysis, the acidic solution extracted more heavy metal concentrations than distilled water, and dichloromethane extracted more but fewer concentrations of PAH compounds than methanol. Shaker extracts with distilled water were non-toxic to P. subcapitata, but were toxic to L. sativa. The acidic extracts were more toxic to P. subcapitata than to L. sativa. The methanolic organic extracts were more toxic to the alga than those obtained with dichloromethane. None of these extracts resulted toxic to L. sativa. Mutagenic effects were only detected in the organic dichloromethane extracts in the presence of metabolic activation. All the inorganic and organic extracts were genotoxic to A. cepa. This study showed that the implementation of different extraction methods together with a battery of bioassays could be suitable tools for detecting toxicity and genotoxicity in sediment samples.

Ecological and toxicological responses in a multistressor scenario: Are monitoring programs showing the stressors or just showing stress? A case study in Brazil

The Metropolitan Region of São Paulo (MRSP) is located in the Brazilian State of São Paulo and reservoirs in this region are vital for water supply and energy production. Changes in economic, social, and demographic trends produced pollution of water bodies, decreasing water quality for human uses and affecting freshwater populations. The presence of emerging pollutants, classical priority substances, nutrient excess and the interaction with tropical-climate conditions require periodic reviews of water policies and monitoring programs in order to detect and manage these threats in a global change scenario. The objective of this work is to determine whether the monitoring program of the São Paulo's Environmental Agency, is sufficient to explain the toxicological and biological responses observed in organisms in reservoirs of the MRSP, and whether it can identify the possible agents causing these responses. For that, we used publicly available data on water quality compiled by this agency in their routine monitoring program. A general overview of these data and a chemometric approach to analyze the responses of biotic indexes and toxicological bioassays, as a function of the physical and chemical parameters monitored, were performed. Data compiled showed temporal and geographical information gaps on variables measured. Toxicological responses have been observed in the reservoirs of the MRSP, together with a high incidence of impairments of the zooplankton community. This demonstrates the presence of stressors that affect the viability of organisms and populations. The statistical approach showed that the data compiled by the environmental agency are insufficient to identify and explain the factors causing the observed ecotoxicological responses and impairments in the zooplankton community, and are therefore insufficient to identify clear cause-effect relationships. Stressors different from those analyzed could be responsible for the observed responses.

Effects of six antibiotics and their binary mixtures on growth of Pseudokirchneriella subcapitata

The effect of ampicillin (AMP), amoxicillin (AMX), cephalotin (CEP), ciprofloxacin (CPF), gentamycin (GEN), and vancomycin (VAN) have been examined individually and as binary mixtures, on a non-target aquatic organism, the green alga Pseudokichneriella subcapitata. The β-lactam antibiotics AMP and AMX were not toxic to the alga at concentrations up to 2000 mgl(-1) (less than 10% of algal growth inhibition), whereas the fluoroquinolone CPF, and the aminoglycoside GEN were the most toxic antibiotics, with an EC50=11.3 ± 0.7 mgl(-1) and 19.2 ± 0.5 mgl(-1), respectively. The cephalosporin CEP and the glycopeptide VAN were less toxic than the last two mentioned, showing an EC50>600 mgl(-1) and 724 ± 20 mgl(-1), respectively. The toxicological interactions of binary mixtures were predicted by the two classical models of additivity: concentration addition (CA) and independent action (IA), and compared to the experimentally determined toxicities over a range of concentrations between 1 and 50 mgl(-1). In all cases a clear synergistic effect was observed, showing that single compound toxicity data are not adequate for the prediction of aquatic toxicities of antibiotic mixtures. Risk assessment was performed by calculating the ratio between predicted environmental concentrations (PEC) and the predicted no effect concentration (PNEC). All the antibiotics tested, excepting GEN, have a potential ecological risk, taking into account the PEC of hospital effluents from Buenos Aires, Argentina. These risks increase when antibiotics are present in binary mixtures.