Integrated occurrence of contaminants of emerging concern, including microplastics, in urban and agricultural watersheds in the State of São Paulo, Brazil.

Contaminants of emerging concern (CECs), including microplastics, have been the focus of many studies due to their environmental impact, affecting biota and human health. The diverse land uses and occupation of watersheds are important parameters driving the occurrence of these contaminants. CECs such as pesticides, drugs, hormones, and industrial-origin substances were analyzed in urban/industrial (Atibaia) and agricultural (Preto/Turvo) watersheds located in São Paulo state, Brazil. A total of 24 CECs were investigated, and, as a result, only 5 (caffeine, carbendazim, atrazine, ametrine and 2-hydroxytrazine) were responsible for 81.73 % of the statistical difference between watersheds contamination profile. The Atibaia watershed presented considerable concentrations of caffeine (ranging from 75 to 2025 ng L-1), while carbendazim (44 to 1144 ng L-1) and atrazine (3 to 266 ng L-1) presented highest levels in Preto/Turvo watershed. In all sampling points, the cumulative potential aquatic life risk assessed by the NORMAN database indicates some level of environmental concern associated to pesticides and caffeine (risk quotient >1). Microplastics had been analyzed in both watersheds, being the white/transparent fragments in size between 100 and 250 µm the most detected in this study. The estimated abundance in the Atibaia watershed ranged from 349 to 2898 items m-3 presenting some influence of pluviosity, while in Rio Preto/Turvo ranged from 169 to 6370 items m-3, being more abundant in the dam area without a clear influence of pluviosity. In both basins, polyethylene and polypropylene were the most detected polymers, probably due to the intense use of single-use plastics in urban areas. Possibly, due to the distinct physic-chemical properties of microplastics and organic CECs, no correlations were observed between their occurrence, which makes us conclude that they have different transport mechanism, behavior, and fate in the environment.

Multiple barriers as an efficient treatment for removing pesticides aiming direct potable reuse: A pilot scale study.

Water reuse for potable purposes can represent a realistic source supply of drinking water in areas with water scarcity. Therefore, combining conventional wastewater treatment technologies with advanced technologies is necessary to remove contaminants and obtain high-quality and safe water. In this study, the pesticides and degradation products, atrazine (ATZ), hydroxyatrazine (ATZOH), deethylatrazine (DEA), deisopropylatrazine (DIA), simazine (SMZ), ametryn (AMT), diuron (DIU), 2,4-D, fipronil (FIP), fipronil sulfide (FIP-SF) and fipronil sulfone (FIP-SN) were evaluated in effluent after membrane bioreactor (MBR), effluent after advanced treatment by multiple barriers (MBR, reverse osmosis, UV/H2O2 and activated carbon), in tap water collected in the urban region of Campinas and in the Atibaia River (water supply source from city of Campinas). The pesticide concentrations in the Atibaia River and the post-MBR effluent ranged between 1 and 434 ng L-1 and 1 and 470 ng L-1, respectively. Therefore, the Atibaia River and the post-MBR effluent had the same magnitude pesticide concentrations. In the production of potable water reuse, after the multiple barriers processes, only fipronil (1 ng L-1) and atrazine (3 ng L-1) were quantified in some of the samples. In tap water from Campinas, atrazine, ATZOH, DEA, diuron, and 2,4-D were quantified in concentrations ranging between 3 and 425 ng L-1. Therefore, when comparing drinking water obtained from conventional treatment with potable water reuse, according to the pesticides studied, it is possible to conclude that the advanced treatment used on a pilot scale is promising for use in a potable water reuse plant. However, studies involving more microbiological and chemical parameters should be conducted to classify potable water reuse as drinking water.

Effects of pasture intensification and sugarcane cultivation on non-target species: A realistic evaluation in pesticide-contaminated mesocosms.

Conventional soil management in agricultural areas may expose non-target organisms living nearby to several types of contaminants. In this study, the effects of soil management in extensive pasture (EP), intensive pasture (IP), and sugarcane crops (C) were evaluated in a realistic-field-scale study. Thirteen aquatic mesocosms embedded in EP, IP, and C treatments were monitored over 392 days. The recommended management for each of the areas was simulated, such as tillage, fertilizer, pesticides (i.e. 2,4-D, fipronil) and vinasse application, and cattle pasture. To access the potential toxic effects that the different steps of soil management in these areas may cause, the cladoceran Ceriophania silvestrii was used as aquatic bioindicator, the dicot Eruca sativa as phytotoxicity bioindicator in water, and the dipteran Chironomus sancticaroli as sediment bioindicator. Generalized linear mixed models were used to identify differences between the treatments. Low concentrations of 2,4-D (<97 µg L-1) and fipronil (<0.21 µg L-1) in water were able to alter fecundity, female survival, and the intrinsic rate of population increase of C. silvestrii in IP and C treatments. Similarly, the dicot E. sativa had germination, shoot and root growth affected mainly by 2,4-D concentrations in the water. For C. sancticarolli, larval development was affected by the presence of fipronil (<402.6 ng g-1). The acidic pH (below 5) reduced the fecundity and female survival of C. silvestrii and affected the germination and growth of E. sativa. Fecundity and female survival of C. silvestrii decrease in the presence of phosphorus-containing elements. The outcomes of this study may improve our understanding of the consequences of exposure of freshwater biota to complex stressors in an environment that is rapidly and constantly changing.

Ecological consequences when organisms avoid a contaminated environment: A study evaluating the toxicity of fipronil.

The ability of aquatic organisms to sense the surrounding environment chemically and interpret these signals correctly is crucial to their survival and ecological niche. This study applied the Heterogenous Multi-Habitat Assay System - HeMHAS to evaluate the avoidance potential of Daphnia magna to detect fipronil-contaminated habitats in a connected landscape after a short (48 h), previous, forced exposure to an environmentally relevant concentration of the same insecticide. The swimming of daphnids was also analyzed by recording the total distance covered. D. magna preferred areas with less contamination, although the effect of fipronil on their swimming ability (a decrease) was observed for all the concentrations tested. The application of non-forced multi-compartment exposure methodologies is a recent trend and is ecologically relevant as it is based on how contamination can really produce changes in an organism's habitat selection. Finally, we consider the importance of more non-forced exposure approaches where Stress Ecology can be aggregated to improve systemic understanding of the risk that contaminants pose to aquatic ecosystems from a broader landscape perspective.

Cross-continental comparative experiences of wastewater surveillance and a vision for the 21st century.

The COVID-19 pandemic has brought the epidemiological value of monitoring wastewater into sharp focus. The challenges of implementing and optimising wastewater monitoring vary significantly from one region to another, often due to the array of different wastewater systems around the globe, as well as the availability of resources to undertake the required analyses (e.g. laboratory infrastructure and expertise). Here we reflect on the local and shared challenges of implementing a SARS-CoV-2 monitoring programme in two geographically and socio-economically distinct regions, São Paulo state (Brazil) and Wales (UK), focusing on design, laboratory methods and data analysis, and identifying potential guiding principles for wastewater surveillance fit for the 21st century. Our results highlight the historical nature of region-specific challenges to the implementation of wastewater surveillance, including previous experience of using wastewater surveillance, stakeholders involved, and nature of wastewater infrastructure. Building on those challenges, we then highlight what an ideal programme would look like if restrictions such as resource were not a constraint. Finally, we demonstrate the value of bringing multidisciplinary skills and international networks together for effective wastewater surveillance.

Physiological responses on the reproductive, metabolism and stress endpoints of Astyanax lacustris females (Teleostei: Characiformes) after diclofenac and ibuprofen exposure.

Diclofenac (DCF) and ibuprofen (IBU) are pharmaceutical compounds frequently detected in aquatic compartments worldwide. Several hazard effects including developmental abnormalities and redox balance impairment have been elucidated in aquatic species, but multiple endocrine evaluations are scarce. Therefore, the present study aimed to assess the disruptive physiological effects and toxicity of DCF and IBU isolated and combined, using females of the native freshwater teleost Astyanax lacustris. In regards to NSAIDs bioavailability, the results showed absence of degradation of IBU and DCF after 7 days of exposure. IBU LC50 for A. lacustris was 137 mgL-1 and females exposed to IBU isolated increased thyroxine (T4) concentration at 24 h and decreased after 96 h; DCF exposure decreased triiodothyronine (T3) concentration at 96 h. Circulating levels of 17ß-estradiol (E2), cortisol (F) and testosterone (T) were not affected by any treatment. HPG and HPI axis genes fshß, pomc and vtg were upregulated after 24 h of IBU exposure, and dio2 was downregulated in DCF fish exposed group after 96 h compared to the mixture. Protein concentration was reduced in muscle and increased in the liver by DCF and mixtures exposures at 24 h; while liver lipids were increased in the mixture groups after 96 h. The study point out the capacity of NSAIDs to affect endocrine endpoints in A. lacustris females and induce changes in energetic substrate content after acute exposure to isolated and mixed NSAIDs treatments. Lastly, the present investigation brings new insights into the toxicity and endocrine disruptive activity of NSAIDs in Latin America teleost species and the aquatic environment.

Ecological Implications on Aquatic Food Webs Due to Effects of Pesticides on Invertebrate Predators in a Neotropical Region.

Predation presents specific behavioral characteristics for each species, and the interaction between prey and predator influences the structuring of the food web. Concerning insects, predation can be affected in different ways, such as exposure to chemical stressors, e.g., pesticides. Therefore, analyses were carried out of the effects of exposure to insecticide fipronil and the herbicide 2,4-D on predation, parameters of food selectivity, and the swimming behavior of two neotropical predatory aquatic insects of the families Belostomatidae (giant water bugs) and larvae of Libellulidae (dragonfly). These predatory insects were exposed for 24 h to a commercial formulation of the chlorophenoxy herbicide, 2,4-D at nominal concentrations of 200, 300, 700, and 1400 µg L-1, and to a commercial formulation of the phenylpyrazole insecticide, fipronil at nominal concentrations of 10, 70, 140, and 250 µg L-1. In a control treatment, the insects were placed in clean, unspiked water. At the end of the exposure, the maximum swimming speed of the predators was evaluated. Afterward, the predators were placed in clean water in a shared environment for 24 h with several prey species, including the cladoceran Ceriodaphnia silvestrii, larvae of the insect Chironomus sancticaroli, the amphipod Hyalella meinerti, the ostracod Strandesia trispinosa, and the oligochaete Allonais inaequalis for 24 h. After this period, the consumed prey was counted. The results reveal that predators from both families changed prey consumption compared with organisms from the control treatment, marked by a decrease after exposure to fipronil and an increase in consumption caused by 2,4-D. In addition, there were changes in the food preferences of both predators, especially when exposed to the insecticide. Exposure to fipronil decreased the swimming speed of Belostomatidae individuals, possibly due to its neurotoxic effect. Exposure to the insecticide and the herbicide altered prey intake by predators, which could negatively influence the complex prey-predator relationship and the functioning of aquatic ecosystems in contaminated areas.

Environmentally Relevant Concentrations of the Insecticide Fipronil Modulated Molecular Response in Chironomus riparius.

Pesticides employed worldwide for crop protection easily reach aquatic systems, which act as the main reservoirs, and become a risk factor for aquatic fauna. Fipronil is a broad-spectrum insecticide acting on the insect nervous system; however, other effects and systems unrelated to this mechanism could be affected in non-target organisms. Thus, the present study aimed to assess the impact of fipronil on the suborganismal response (gene expression and enzymatic activity) of Chironomus riparius larvae as a model organism in ecotoxicology. To this end, short-term toxicity tests were carried out with fourth-instar larvae exposed to 0.001, 0.01, and 0.1 µg L-1 of fipronil for 24 and 96 h. Messenger RNA levels of 42 genes related to diverse metabolic pathways were analyzed by real-time polymerase chain reaction, complemented with catalase (CAT), glutathione S-transferase (GST), and acetylcholinesterase (AChE) activities. Few effects were observed at 24 h; however, after longer exposure (96 h), genes involved in the endocrine, detoxification, stress, and immune response pathways were altered. Moreover, fipronil at 96 h increased CAT and GST activity at 0.01 µg L-1 and AChE at the highest concentrations. The results demonstrate that even low environmentally relevant fipronil concentrations can modulate the molecular response of several cellular pathways in C. riparius after short-term exposure. These results bring new information about the underlying response of fipronil and its mode of action on a key aquatic invertebrate. Despite no effects on mortality, strong modulation at the suborganismal level emphasizes the advantage of biomarkers as early damage responses and the harmful impact of this pesticide on freshwater organisms. Environ Toxicol Chem 2024;43:405-417. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Chlorination of Emerging Contaminants for Application in Potable Wastewater Reuse: Disinfection Byproduct Formation, Estrogen Activity, and Cytotoxicity.

With increasing water scarcity, many utilities are considering the potable reuse of wastewater as a source of drinking water. However, not all chemicals are removed in conventional wastewater treatment, and disinfection byproducts (DBPs) can form from these contaminants when disinfectants are applied during or after reuse treatment, especially if applied upstream of advanced treatment processes to control biofouling. We investigated the chlorination of seven priority emerging contaminants (17ß-estradiol, estrone, 17α-ethinylestradiol, bisphenol A (BPA), diclofenac, p-nonylphenol, and triclosan) in ultrapure water, and we also investigated the impact of chlorination on real samples from different treatment stages of an advanced reuse plant to evaluate the role of chlorination on the associated cytotoxicity and estrogenicity. Many DBPs were tentatively identified via liquid chromatography (LC)- and gas chromatography (GC)-high resolution mass spectrometry, including 28 not previously reported. These encompassed chlorinated, brominated, and oxidized analogs of the parent compounds as well as smaller halogenated molecules. Chlorinated BPA was the least cytotoxic of the DBPs formed but was highly estrogenic, whereas chlorinated hormones were highly cytotoxic. Estrogenicity decreased by ∼4-6 orders of magnitude for 17ß-estradiol and estrone following chlorination but increased 2 orders of magnitude for diclofenac. Estrogenicity of chlorinated BPA and p-nonylphenol were ∼50% of the natural/synthetic hormones. Potential seasonal differences in estrogen activity of unreacted vs reacted advanced wastewater treatment field samples were observed.

Fate and toxicity of 2,4-D and fipronil in mesocosm systems.

2,4-D and fipronil are among Brazil's most used pesticides. The presence of these substances in surface waters is a concern for the aquatic ecosystem health. Thus, understanding the behavior of these substances under environmentally relevant conditions is essential for an effective risk assessment. This study aimed to determine the degradation profiles of 2,4-D and fipronil after controlled application in aquatic mesocosm systems under influencing factors such as environmental aspects and vinasse application, evaluate pesticide dissipation at the water-sediment interface, and perform an environmental risk assessment in water and sediment compartments. Mesocosm systems were divided into six different treatments, namely: control (C), vinasse application (V), 2,4-D application (D), fipronil application (F), mixture of 2,4-D and fipronil application (M), and mixture of 2,4-D and fipronil with vinasse application (MV). Pesticide application was performed according to typical Brazilian sugarcane management procedures, and the experimental systems were monitored for 150 days. Pesticide dissipation kinetics was modeled using first-order reaction models. The estimated half-life times of 2,4-D were 18.2 days for individual application, 50.2 days for combined application, and 9.6 days for combined application with vinasse. For fipronil, the respective half-life times were 11.7, 13.8, and 24.5 days. The dynamics of pesticides in surface waters resulted in the deposition of these compounds in the sediment. Also, fipronil transformation products fipronil-sulfide and fipronil-sulfone were quantified in water 21 days after pesticide application. Finally, performed risk assessments showed significant potential risk to environmental health, with RQ values for 2,4-D up to 1359 in freshwater and 98 in sediment, and RQ values for fipronil up to 22,078 in freshwater and 2582 in sediment.

Analytical determination of tryptoquialanines A and B: Ensuring the quality and safety of orange juices.

Although orange juice is a popular beverage worldwide, fruit distribution, storage, and processing can facilitate fungal infection by Penicillium digitatum; leading to the production of tremorgenic alkaloids, specifically tryptoquialanines A (TA) and B (TB). An Analytical method was developed and validated based on QuEChERS and LC-MS/MS analysis to determine the levels of TA and TB in fresh, industrial, and homemade orange juices. Excellent linearity was observed in the method over a high range of 1-1000 µg/kg and low range of 1-75 µg/kg with R2 ≥ 0.998. The LOD and LOQ were 1 and 3 µg/kg, respectively. Recoveries showed values between 57 and 83 %, with RSD ≤ 13 %. Our data indicated a higher prevalence of mycotoxin TA in fresh and industrial orange juices. Reduction in TA and TB content after thermal and HPP treatments were ≤ 32 %. However, thermal treatment was more effective in reducing TA and TB contents.

Uncovering the impact of agricultural activities and urbanization on rivers from the Piracicaba, Capivari, and Jundiaí basin in São Paulo, Brazil: A survey of pesticides, hormones, pharmaceuticals, industrial chemicals, and PFAS.

Rivers in Southeast Brazil are essential as sources of drinking water, energy production, irrigation, and industrial processes. The Piracicaba, Capivari, and Jundiaí rivers basin, known as the PCJ basin, comprises major cities, industrial hubs, and large agricultural areas, which have impacted the water quality in the region. Emerging contaminants such as pesticides, hormones, pharmaceuticals, industrial chemicals, and per- and polyfluoroalkyl substances (PFAS) are likely to be released into the rivers in the PCJ basin; however, the current Brazilian legislation does not require monitoring of most of these chemicals. Thus, the extent of emerging contaminants pollution and their risks to aquatic and human life in the basin are largely unknown. In this study, we investigated the occurrence of several pesticides, hormones, pharmaceuticals, and personal care products in 15 sampling points across the PCJ basin, while industrial chemicals and PFAS were assessed in 11 sampling points. The results show that agriculture and industrial activities are indeed causing the pollution of most rivers. Multivariate analysis indicates that some sampling points, such as Jundiaí, Capivari, and Piracicaba rivers, are largely impacted by pesticides used in agriculture. In addition, to the best of our knowledge, this is the first study reporting the presence of PFAS in rivers in São Paulo, the most populous state in Brazil. Four out of eight species of PFAS assessed in our study were detected in at least 5 sampling points at concentrations ranging from 2.0 to 50.0 ng L-1. The preliminary risk assessment indicates that various pesticides, caffeine, industrial chemicals, and PFAS were present at concentrations that could threaten aquatic life. Notably, risk quotients of 414, 340, and 178 were obtained for diuron, atrazine, and imidacloprid, respectively, in the Jundiaí River. Our study suggests that establishing a comprehensive monitoring program is needed to ensure the protection of aquatic life and human health.

Environmental concentrations of cadmium and fipronil, isolated and combined, impair the survival and reproduction of a Neotropical freshwater copepod.

Anthropogenic activities such as agriculture and industry increase contaminants that reach the water bodies, potentially threatening the biota. Most likely, these pollutants occur in complex mixtures. The effects on organisms can be potentiated (synergism) or reduced (antagonism) according to the interaction between the stressors or the species. Cadmium (Cd) is a toxic metal present in phosphate fertilizers, and fipronil is an insecticide broadly used in sugarcane crops. Copepods are important energy transfer links in aquatic environments, and effects on this group impact the whole trophic chain. In this study, we evaluated the responses of the freshwater Calanoida copepod Notodiaptomus iheringi, naturally present in water bodies that can be affected by sugarcane cultures in Brazil. The organisms were exposed to environmental concentrations of Cd and fipronil, isolated and in the mixture, in acute (48 h) and sub-chronic (8 d) tests. Our data indicate that both contaminants affect the survival of the organisms in acute or sub-chronic exposures. Cadmium did not affect egg production or hatching, while fipronil impacted these endpoints negatively. The Cd-fipronil combination resulted in antagonistic responses in survival (acute and sub-chronic) and egg production. A synergistic response was observed in egg hatching. Our results suggest that Cd presents a protective effect in the mixture with fipronil; however, it is not enough to prevent egg-hatching inhibition. These responses highlight how tricky it is to deal with pollutants' interaction in environmental concentrations since synergism is the most common response to metal-pesticide mixtures. Our data point out N. iheringi as a sensitive organism in the presence of contaminants and reflects the threat of chemical mixtures in concentrations found in water bodies close to sugarcane crops in Brazil.

How natural and anthropogenic factors should drive microplastic behavior and fate: The scenario of Brazilian urban freshwater.

Brazil maintains its position at the top of the global ranking of plastic producers, yet recycling efforts have been incipient. Recent data reveals an annual production of approximately 14 million tons of plastic waste, not accounting for the surge in the usage of plastic masks and related materials due to the COVID-19 pandemic. However, what remains largely unreported is that over half of post-consumer plastic packaging in Brazil is managed without any monitoring, and it remains unclear how this will contribute to the occurrence of plastic waste and microplastics in Brazilian freshwaters. This scenario requires the consideration of several other crucial factors. Studies have been carried out mainly in marine and estuarine waters, while data on freshwaters are lacking. Brazil has continental dimensions and the highest water availability on the planet, yet the demand for water is greatest in regions with medium to low supply. Many densely populated Brazilian urban areas face chronic flood problems, possess inadequate levels of wastewater treatment, and display inadequate solid waste management practices. Consequently, urban freshwater with tropical characteristics in Brazil presents an intriguing scenario and is complementary to the most commonly studied marine environments. In this study, we explore the nuances of pollution in Brazilian urban freshwater and discuss how various parameters, such as organic matter, suspended solids, temperature, and pH, among others, influence the behavior of microplastics and their interactions with organic and inorganic contaminants. Furthermore, we address how microplastic conditions, such as biofouling, the type of plastic, or degradation level, may impact their behavior. By analyzing how these conditions change, we propose priority themes for investigating the occurrence of microplastics in Brazilian urban freshwater systems under different degrees of human impact. Ultimately, this study aims to establish a network dedicated to standardized monitoring of microplastic pollution in Brazilian urban freshwaters.

Occurrence of contaminants of emerging concern and their risks to the Pantanal Sul-Mato-Grossense aquatic biota, Brazil.

The Aquidauana River is an important ecological corridor in the Pantanal biome. However, the growth of agricultural and urban areas along its banks has contributed to the deterioration of its water quality, consequently putting the aquatic biota at risk. Our objectives were to evaluate: 1) the composition of the landscape around six sampling sites located in the Aquidauana River middle section; and 2) the quality of its water by determining limnological parameters, concentrations of contaminants of emerging concern (CECs), and the risks to native aquatic biota. Water samples were collected in November 2020. We observed the conversion of native riparian vegetation to extensive pasture areas and anthropic occupation around the sampling sites. We observed that the chlorophyll and total ammoniacal nitrogen values were above the standards established by Brazilian legislation in all samples. Studies focused on the quantification of CECs in the Pantanal waters are scarce, and to the best of our knowledge, this is the first study that investigated the presence of pharmaceuticals in the Aquidauana River. All 30 CECs analyzed were detected in at least one water sample. Eleven CECs were quantified with eight pesticides (atrazine, diuron, hexazinone, tebuthiuron, azoxystrobin, carbendazim, tebuconazole, and fipronil) and one atrazine degradation product (atrazine-2-hydroxy), caffeine, and bisphenol A. The concentrations of atrazine herbicide observed in the water samples pose risks for protecting aquatic biota (RQs >1). Therefore, the native biota of the Pantanal biome is vulnerable to several types of toxic contaminants observed in the water, which can cause the disappearance of native and endemic species in this region. Establishing a monitoring program, improving sanitation infrastructure, and intensifying good agricultural practices are essential for reducing and controlling the entry of CECs into the Aquidauana River and the Pantanal water system.

The acute effects of fipronil and 2,4-D, individually and in mixture: a threat to the freshwater Calanoida copepod Notodiaptomus iheringi.

The magnitude of copepods' responses to pesticides, individually and in mixture, is little understood. The aims of this study were to evaluate: (i) the effects of the pesticides fipronil and 2,4-D, individually and in mixture, on the freshwater copepod Notodiaptomus iheringi; and (ii) the survival and the feeding rate of copepods after the exposure. Acute toxicity tests using the commercial formulations of fipronil and 2,4-D, individually and in mixture, were performed. The LC10-48h, LC20-48h, and LC50-48h of fipronil to N. iheringi were 2.38 ± 0.48, 3.08 ± 1.14, and 4.97 ± 3.30 µg L-1, respectively. For 2,4-D the LC10-48h, LC20-48h, and LC50-48h were 371.18 ± 29.20, 406.93 ± 53.77, and 478.24 ± 107.77 mg L-1, respectively. Morphological damages on the copepods exposed to pesticides were observed at all concentrations. Fungal filaments covering dead organisms were presented at the treatment highest concentration (R5:7.43 ± 2.78 µg L-1 fipronil). The mixture of the pesticides presented synergistic effects on the mortality of N. iheringi. Post-exposure tests showed no difference between the treatments and the control on the mortality and on the feeding rate for 4 h. However, since delayed toxicity of pesticides can occur, longer post-exposure tests using N. iheringi should be tested. N. iheringi is a key species in the aquatic Brazilian ecosystem and showed sensitivity to fipronil and 2,4-D; thus, more studies with this species assessing other responses are recommended.

Atrazine and its degradation products in drinking water source and supply: Risk assessment for environmental and human health in Campinas, Brazil.

Atrazine is a broad-spectrum herbicide widely used worldwide to control grassy and broadleaf weeds. Atrazine's popularity is attributable to its cost-effectiveness and reliable performance. Relatedly, it is also an important micropollutant with a potential negative impact on biodiversity and human health. Atrazine has long been regularly detected in several environmental compartments, and its widespread use has resulted in ubiquitous and unpreventable contamination. Among pesticides sold in Brazil, atrazine has remained among the top-ranked active ingredients for the last several years. Thus, this study aimed to evaluate the occurrence of atrazine and three degradation products (hydroxyatrazine, desisopropylatrazine, and desethylatrazine) in surface water (Capivari and Atibaia rivers) and treated water, monthly sampling from two drinking water treatment plants in Campinas (São Paulo, Brazil). An analytical method using solid-phase extraction (SPE) and liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed to determine target compounds simultaneously. The method presented instrument quantification limits from 0.5 to 4.0 ng mL-1 and recovery values from 80 to 112%, with a maximum relative standard deviation of 6%. All analytes had a detection frequency of 100% from 2 to 2744 ng L-1. Statistical analysis showed no analyte removal after conventional water treatment. Also, the Capivari River showed greater analyte concentration than the Atibaia River. Performed risk assessments according to current Brazilian standards showed no human and environmental health risks. However, other risk assessment approaches may indicate potential risks, advocating for further research and ongoing surveillance.

Exposure to fipronil, 2,4-D and vinasse influences macroinvertebrate assemblage structure: An experimental mesocosm approach.

Sugarcane is one of the main monocultures in Brazil and widely uses herbicide 2,4-D and fipronil insecticide. In addition, vinasse can be mentioned as it is widely used in this plantation. These compounds occurring simultaneously in the aquatic environment can potentiate the deleterious effects on organisms. Thus, this study aimed to evaluate the composition, abundance and ecological indices of the benthic macroinvertebrate community, as well as its ability to reestablish itself considering environmental contamination by the pesticides Regent® 800WG (active ingredient - a.i. fipronil) (F) and DMA® 806BR (a.i. 2,4-D) (D) and vinasse (V), alone and in mixtures: pesticides - M and the three contaminants - MV. The study was conducted using open-air mesocosms. The macroinvertebrate community was monitored by colonization structures, the physical-chemical parameters, metals and pesticides were determined and the effects of contaminants were evaluated over the exposure time in 1, 7, 14, 28, 75 to 150 days. A multiple regression was performed between the water parameters and significant relationships were found between parameters associated with vinasse contamination (pH, total nitrogen, turbidity, and dissolved oxygen) and concentration of fipronil and the ecological variables studied. Over time, changes were observed in the composition of the community. The dominance and richness increased in treatments V and MV. The family Chironomidae and subclass Oligochaeta were more sensitive to the treatment V and MV, while individuals from the families Phoridae, Ephydridae and Sciomyzidae were occasionally found (depending on the experimental time) in these treatments. The insects were sensitive to treatments F and M, disappearing in these mesocosms after contamination, reappearing only after 75 days. The results reveal that sugarcane management practices associated with the use of pesticides and vinasse as fertilizer pose risks to the macroinvertebrate community with consequences for the trophic chains, given its importance in freshwater ecosystems and adjacent terrestrial environments.

Toxicity of fipronil and 2,4-D pesticides in Daphnia similis: a multiple endpoint approach.

In Brazil, among the pesticides widely applied simultaneously in sugarcane monocultures are the Regent® 800 WG insecticide (active ingredient (a.i.) fipronil) and the DMA® 806 BR herbicide (a.i. 2,4-D). Thus, this study aimed to investigate, through different endpoints, the effects of the fipronil and 2,4-D pesticides, isolated and as mixtures, on the cladoceran Daphnia similis. To do this, acute toxicity tests were carried out with the compounds acting in isolation and in mixture, where the survival of the organisms was evaluated, and chronic toxicity tests with the isolated compounds, where reproduction and maternal and neonatal body length were evaluated. In this study, the physiological endpoints of D. similis were also analyzed, through the analysis of feeding rates (filtration and ingestion) in exposure and post-exposure scenarios, in order to verify the cladoceran food recovery capacity. In addition, D. similis data were compared with other species when exposed to the studied pesticides, using species sensitivity distribution curves. Acute toxicity tests of the fipronil and 2,4-D showed an average EC50-48 h of 66.68 µg a.i./L and 327.07 mg a.i./L, respectively. In both cases, D. similis showed lower sensitivity compared to other species. For the mixture test, the evaluation by the IA model (independent action) and deviation DR (dose ratio dependent) indicated the occurrence of mostly antagonistic effects. The chronic test with fipronil showed a decrease in the fecundity of the organism at a concentration of 16 µg a.i./L, a concentration already found in aquatic environments. For 2,4-D, no significant differences were observed for reproduction at the concentrations tested. Regarding the maternal body length, there were no significant changes when D. similis were exposed to both fipronil and 2,4-D, but these differences were observed in the body length of the neonates only for 2,4-D. There were no significant changes in the feeding rates of the organisms when exposed to both pesticides.