Bacteriophages Against Bacterial Infections in Poultry Systems: A Scientometric Review.

Poultry production faces challenges from bacterial infections, aggravated by antibiotic resistance, affecting bird welfare and the industry's economy. Bacteriophages show promise as a solution, but their use in poultry systems is still limited. This study uses scientometric analysis to investigate the incidence of bacterial infections in poultry systems and bacteriophage application trends. The Web of Science database was used, and the articles were refined by searching for keywords that included the most rep orted bacteria in the different phases of poultry farming and the application of phages. The articles were analyzed using the CiteSpace and Excel software, allowing the evaluation of publication trends, influential countries, and correlations with antimicrobial resistance and the use of bacteriophages. Results highlight Escherichia coli prevalence in poultry systems and reveal a correlation between the number of publications and poultry productivity, with the United States and China leading both aspects. Findings offer insights into bacterial control gaps in poultry systems, underscoring the need for further research and practical strategies.

Does the atrazine increase animal mortality: Unraveling through a meta-analytic study.

Atrazine is one of the most used herbicides in the world, although it is banned in several countries. Pollution of terrestrial and aquatic ecosystems represents a threat to non-target organisms, with various damages already reported in different species. However, there is controversy in studies on atrazine. The question of whether atrazine increases animal mortality is not yet clearly resolved. In this context, this study aimed to carry out a meta-analytic review, focusing on studies on environmental concentrations of the herbicide atrazine to evaluate its lethal effects on various animal species. We identified and analyzed 107 datasets through a selection process that used the Scopus, PubMed, and Web of Science (WoS) databases. A significant increase in the mortality rate of animals exposed to environmental concentrations of atrazine was observed. Nematodes, amphibians, molluscs, insects, and fish showed increased mortality after exposure to atrazine. Animals in the larval and juvenile stages showed greater susceptibility when exposed to different concentrations of atrazine. Furthermore, both commercial and pure formulations resulted in high mortality rates for exposed animals. Atrazine and other pesticides had a synergistic effect, increasing the risk of mortality in animals. There are still many gaps to be filled, and this study can serve as a basis for future regulations involving atrazine.

From chaos to clarity: The scientometric breakthrough in COVID-19 research.

BACKGROUND: The COVID-19 pandemic paralyzed the world for over three years, generating unprecedented social changes in recent human history. AIMS: We aimed to scientometrically summarize a global and temporal overview of publications on COVID-19 in the two worst years of the pandemic and its progression in early 2022, after the start of vaccination. METHODS: Using the Web of Science database, this review covered the period from late 2019 to March 2022 and included all publications identified using the following terms: "SARS-CoV-2", "COVID-19", "Coronavirus Disease 19", and "2019-nCoV". We retrieved 268,904 publications, with evident global spreading, demonstrating that the pandemic triggered worldwide scientific research efforts. RESULTS: Within the dataset, 195 countries have published about Covid-19. In initial publications, a solid trend in genotyping, sequencing, and detection of the virus was evident; however, in the development of the pandemic, new knowledge and research focus gained relevance, with continental solid trends, revealed by the keywords sustainability (eastern Europe); material sciences (Asia); public and mental health (Africa); information sciences (western Europe); education (Latin America). It identified high-impact research, mainly on diagnosis and vaccines, but also equally essential topics for returning life to the new normal, such as mental health, education, and remote work. The world experienced a highly transmissible infection that proved how fragile we are regarding organization and society. CONCLUSIONS: It is necessary to learn from such an event and establish a protocol of actions and measures to be taken and avoided in a health emergency, aiming to act differently from the chaos experienced during the pandemic. Following the One Health approach, humanity must be aware of the need for more sustainable attitudes, given the inseparability of human beings from the environment.

Relationship between SARS-CoV-2 vaccination and cases, program breakthrough cases, and deaths in Dois Vizinhos, Paraná, Brazil.

Several vaccines have been produced in 2 years of the COVID-19 pandemic to control the infection outbreak. This study demonstrated the success of vaccination in controlling COVID-19 cases and deaths in a small city (41 424 people) with a low population density in Brazil. This study was based on a 1-year dataset since the application of the first dose in January 2021. The results show a reduction in positive cases and deaths as the vaccination coverage increased in the city, mainly after 15 000 inhabitants were vaccinated (35.21% of the population) in July 2021. At the time, 49.06% of administered vaccines were ChAdOx1-S recombinant, 39.80% inactivated SARS-CoV-2 virus (CZ02 strain), 9.70% Tozinameran, and 1.44% Ad26.COV2-S recombinant. From August 2021, a marked reduction in daily positive cases and deaths was observed, and incidence (≤2.49 per 1000 inhabitants) and mortality (≤0.02 per 1000 inhabitants) rates remained stabilized until January 2022, when a new outbreak occurred upon the emergence of the Omicron variant. However, the mortality rate (0.07 per 1000 inhabitants) remained low regardless of the Omicron high incidence rate (68.41 per 1000 inhabitants). These data demonstrate the COVID-19 vaccination effectiveness with a threshold of 35.21% of the population vaccinated in this city model.

Effects of Heat Stress in Dairy Cows Raised in the Confined System: A Scientometric Review.

Due to climate change, heat stress is a growing problem for the dairy industry. Based on this, annual economic losses in the dairy sector are verified mainly on a large scale. Despite several publications on thermal stress in lactating dairy cows in confinement systems, there need to be published reviews addressing this issue systematically. Our objective was to scientometrically analyze the effects of heat stress in dairy cows managed in a confinement system. Based on PRISMA guidelines, research articles were identified, screened, and summarized based on inclusion criteria for heat stress in a confinement system. Data was obtained from the Web of Science. A total of 604 scientific articles published between 2000 and April 2022 were considered. Data was then analyzed using Microsoft Excel and CiteSpace. The results pointed to a significant increase in studies on heat stress in lactating cows housed in confinement systems. The main research areas were Agriculture, Dairy Animal Science and Veterinary Sciences. The USA showed the highest concentration of studies (31.12%), followed by China (14.90%). Emerging themes included heat stress and behavior. The most influential journals were the Journal of Dairy Science and the Journal of Animal Science. The top authors were L. H. Baumgard and R. J. Collier. The leading institutions were the Chinese Academy of Agricultural Sciences, followed by the State University System of Florida and the University of Florida. The study maps the significant research domains on heat stress of lactating cows in confinement systems, discusses implications and explanations and highlights emerging trends.

Identifying global trends and gaps in research on pesticide fipronil: a scientometric review.

Fipronil is a broad potent insecticide that belongs to the phenylpyrazole chemical family. Its action mode acting in the presynaptic and postsynaptic blocking the chlorine ions by the neurotransmitters GABA. It is considered highly toxic, and in some countries, its use has been prohibited. The objective of this review is to perform a scientometric analysis for global measurement of the research on the insecticide fipronil. All information in this study was searched in the Web of Science (WoS) database in December 2021. The search was carried using the term "fipronil." Thus, 2362 studies were selected. Most selected articles showed toxicity effects of fipronil on non-target organisms, analytical methods to detect the insecticide, environmental degradation processes, and efficiency in reducing insects through its use. The H index for this dataset was 91. The cooperation network of the authors among countries showed the USA as the most notorious, with 30.6% of studies, followed by China (15.7%) and Brazil (10.9%). There are many studies on the toxicity of fipronil in bees, forms of degradation, and effectiveness of this insecticide. The present work presents suggestions pointed out in the articles for further research and highlights the importance of studies involving fipronil, as well as studies of alternative pest control.

Does exposure to environmental 2,4-dichlorophenoxyacetic acid concentrations increase mortality rate in animals? A meta-analytic review.

The 2,4-dichlorophenoxyacetic acid (2,4-D) is an auxinic herbicide widely used in agriculture that is effective in controlling weeds. It is directly applied to the soil, to ponds or sprayed onto crops; thus, it can progressively accumulate in environmental compartments and affect non-target organisms. The aim of the present meta-analytic review is to investigate the toxic effects of 2,4-D, based on a compilation of results from different studies, which were synthesized to form a statistically reliable conclusion about the lethal effect of potentially ecological concentrations of 2,4-D in several animal species. The search was carried out in the Web of Science and Scopus databases. After the selection process was over, 87 datasets were generated and analyzed. The overall effect has indicated significant increase in the mortality rate recorded for animals exposed to environmental concentrations of 2,4-D compared to the control in the experiment (unexposed animals). The segregation of animals into taxonomic categories has shown that fish and birds presented higher mortality rates after exposure to the investigated substance. The present meta-analysis indicated larval and adult animals were susceptible among the ontogenetic development stages. Juvenile individuals exposed to different 2,4-D concentrations did not show significant difference in comparison to the control. Organisms exposed to 2,4-D immersion were the most impacted compared to those exposed by oral, spray and contact. Animals subjected to commercial formulation presented higher mortality rate than the analytical standard. Thus, 2,4-D can, in fact, increase mortality rate in animals, but it depends on species sensitivity, life stage and exposure route. This is the first meta-analytical study evaluating the mortality rate after 2,4-D exposure in several animal species.

Bees and pesticides: the research impact and scientometrics relations.

Bees are fundamental insects in agroecosystems, mainly due to pollination. However, its decline has been observed in recent years, and the contamination by pesticides is suspected to be responsible. This relationship is the objective of our research, which is the first scientometric study on this subject. The data were obtained from the Web of Science database (1231) and were analyzed using Microsoft Office Excel and CiteSpace. The results point to a significant increase in pesticide and bee reseach in the last 15 years in the most influential scientific journals. The USA and France have the largest number of publications and a moderade relationship between this trait and GDP (gross domestic product) was observed (r = 0.80; r2 = 0.60). There is no correlation between the use of pesticides and studies of the effects on pollinators and the use of pesticides and the countries' GDP. In general, studies have shown the negative effects of the contamination by pesticides on bees; however, most publications are with bees of the Apis genus, and therefore it is necessary to explore the action of pesticides on bumble bees and wild bees, as well furthur as studies are needed regarding the sublethal effects of these products on bees as the number of molecules used in the management of agricultural crops is vast.

Analysis of global trends and gaps for studies about 2,4-D herbicide toxicity: A scientometric review.

2,4-dichlorophenoxyacetic acid (2,4-D) is a herbicide that is used worldwide in agricultural and urban activities to control pests, reaching natural environments directly or indirectly. The research on 2,4-D toxicology and mutagenicity has advanced rapidly, and for this reason, this review summarizes the available data in Web of Science (WoS) to provide insights into the specific characteristics of 2,4-D toxicity and mutagenicity. Contrary to traditional reviews, this study uses a new method to quantitatively visualize and summarize information about the development of this field. Among all countries, the USA was the most active contributor with the largest publication and centrality, followed by Canada and China. The WoS categories 'Toxicology' and 'Biochemical and Molecular Biology' were the areas of greatest influence. 2,4-D research was strongly related to the keywords glyphosate, atrazine, water and gene expression. The studies trended to be focused on occupational risk, neurotoxicity, resistance or tolerance to herbicides, and to non-target species (especially aquatic ones) and molecular imprinting. In general, the authors have worked collaboratively, with concentrated efforts, allowing important advances in this field. Future research on 2,4-D toxicology and mutagenicity should probably focus on molecular biology, especially gene expression, assessment of exposure in human or other vertebrate bioindicators, and pesticide degradation studies. In summary, this scientometric analysis allowed us to make inferences about global trends in 2,4-D toxicology and mutagenicity, in order to identify tendencies and gaps and thus contribute to future research efforts.

Are Our Farm Workers in Danger? Genetic Damage in Farmers Exposed to Pesticides.

Modern agriculture, practiced after the "green revolution" worldwide, aims to maximize production in order to provide food for the growing world population. Thus, farmers are required to modernize their practices through the mechanization of land use and, above all, the use of chemical pesticides to control agricultural pests. However, in addition to combating the target pest, chemical pesticides indirectly affect a wide range of species, including humans, leading to health damage. Among the main problems caused by the use of pesticides is the genotoxicity caused by chronic exposure. The present study aims to verify the occurrence of genetic damage in farmers who are occupationally exposed to agrochemicals compared to people of other professions that do not use toxic substances (control group). The research was conducted with 36 male participants (18 farmers and 18 control group, ages 24⁻71 for the farmer group and 22⁻61 for the control group). The comet assay and micronucleus test results revealed a higher rate of genetic damage in the group of farmers than in the control group. A questionnaire answered by the farmers showed that the Personal Protect Equipment (PPE) is used incorrectly or not used. In summary, our results indicate that farmers are exposed to occupational hazards. To mitigate this risk, we conducted awareness campaigns to notify the farmers of the risks and highlight the importance of using PPE correctly. Intensive efforts and training are thus required to build an awareness of safety practices and change the attitudes of farm workers in the hope of preventing harmful environmental and anthropogenic effects.

Reproductive indicators of the endemic species Astyanax bifasciatus (Teleostei: Characidae) in a tributary of the Lower Iguaçu River Basin, Brazil

The reproductive process promotes morphophysiological and behavioral changes in fish species throughout their life cycle. Its success is vital to define their resilience in the environment. This study aimed to evaluate the reproductive biology of the endemic fish species Astyanax bifasciatusin a tributary of the Lower Iguaçu River Basin, Paraná, Brazil. Fish were collected monthly at four sites along the Jirau Alto River in the city of Dois Vizinhos from October 2015 to September 2016. A standardized catch effort with gill nets and fish traps was used. In the laboratory, standard length and total weight were recorded. After anesthesia, the animals were sectioned to macroscopically determine the sex, sexual maturity stage, and presence of celomatic fat. The gonads and liver were removed to determine the gonadosomatic and hepatosomatic indexes, respectively. A total of 160 individuals (104 femalesand 56 males) were used. The gonadosomatic index, frequency of the gonadal maturation stages, and condition factor showed a long reproductive period with two investment cycles for both sex. Length at first sexual maturity was 4.57 cm for females and 3.56 cm for males. The reproductive data corroborate the generalist profile of the species and demonstrate a high degree of adaptive capacity, even in smaller tributaries.

Waterborn Genotoxicity in Southern Brazil Using Astyanax bifasciatus (Pisces: Teleostei).

Water bodies are often negatively affected by unmediated expansion of surrounding human populations. This makes it essential to establish growth planning strategies that balance productivity and sustainability when creating a viable ecological equilibrium. This study aimed to evaluate genotoxic effects in southern Brazil, using biomarkers in the fish Astyanax bifasciatus, during summer and winter of 2016. The erythrocytic nuclear abnormalities test and the micronucleus test as well as the blood and liver comet assay were used to determine genetic biomarker damage. Four locations and a control point (CP) were sampled in this study. The results demonstrated genotoxicity at all sample locations in the river as compared to the CP in all tests. This is concerning as this water source is the only supply for human populations adjacent and further flows into the greater Iguaçu river basin.

Performance of biomarkers metallothionein and ethoxyresorufin O-deethylase in aquatic environments: A meta-analytic approach.

The preservation of natural environments guarantees the conservation of biodiversity and ecosystem processes. Biomonitoring programs in preserved sites can be carried out using molecular biomarkers, which reflect possible stresses that exist in the monitored location. The metallothionein (MT) proteins and isoenzyme Cytochrome P4501A (CYP4501A) are among the most used biomarkers and reflect the detoxification of metal and organic xenobiotics, respectively. This study aimed to assess the performance of these biomarkers in natural aquatic environments using a meta-analytic approach. The data search was conducted in ISI Web of Science™, considering papers published until August 2016. Studies included in this research needed to compare reference or control sites and sites under stress and be conducted in situ. In general, both biomarkers were useful when comparing control sites with sites under stress. Moreover, when the data were categorized into groups of organisms, mainly bivalves and fishes, there were differences between the groups and between the monitored environments, marine or freshwater. The use of these biomarkers in fish is suitable for freshwater environments, and bivalves are suitable for marine environments. We concluded that the concomitant use of vertebrate and invertebrate bioindicators is useful to develop an effective biomonitoring program and to avoid biases due the physiology of the selected bioindicator.

Fish welfare: the state of science by scientometrical analysis / Bem-estar em peixes: o status da ciência por meio de análise cienciométrica

In 2014, Brazil produced 474.33 thousand tons of captive-bred fish. In addition, regulatory agencies of animal ethics and welfare have recently encouraged experiments to be done using simpler vertebrates, such as fish. The aim of this article was to perform a scientometric analysis of scientific production that deals with fish welfare, in an attempt to find trends and gaps in this line of research. Our analyses showed a growing concern about fish welfare, although several questions remained inadequately covered. The most studied species was the Atlantic salmon, with Norway having the most publications on this theme. There are controversies among scientists about fish capacity for suffering and enjoyment (sentience). As regards slaughter or euthanasia, some studies showed that some methods are more endorsed than others, because they effectively reduce suffering and improve the appearance of the meat. In respect of animals used for experimentation, the most recommended substances were benzocaine and MS222. Thus, despite the importance of this subject, few studies are decisive and there is still no consensus on how to improve fish welfare or even on how to reduce suffering at the moment of slaughter.

Em 2014, o Brasil produziu 474,33 mil toneladas de peixes em cativeiro. Além disto, há um recente incentivo dos órgãos reguladores da ética e do bem-estar animal para que experimentos sejam feitos com vertebrados mais simples, tais como peixes. O objetivo do presente trabalho foi realizar uma análise cienciométrica da produção científica que trata do bem-estar de peixes e se preocupa com eles, em uma tentativa de encontrar tendências e lacunas nessa linha de pesquisa. Nossas análises mostraram uma crescente preocupação com o bem-estar em peixes, apesar de várias questões continuarem deficientes. A espécie mais utilizada nos estudos foi o salmão do Atlântico, e o país com mais publicações nessa temática foi a Noruega. Percebe-se que existem controvérsias entre cientistas quanto à capacidade de sofrimento desses animais, a senciência. Quanto ao abate ou à eutanásia, estudos mostraram que alguns métodos são mais aconselháveis que outros, pois efetivamente irão reduzir o sofrimento e melhorar a apresentação da carne. Para animais de experimentação, as substâncias mais recomendadas foram a benzocaína e o MS222. Assim, apesar da importância do tema, poucos estudos são definitivos, inexistindo ainda consenso sobre os métodos de melhoria do bem-estar em peixes e sobre como reduzir o sofrimento no momento do abate

Does exposure to glyphosate lead to an increase in the micronuclei frequency? A systematic and meta-analytic review.

Glyphosate-based herbicides are among the most used pesticides worldwide. Reviews on the safety of glyphosate have been conducted by several regulatory agencies and researches centers, many times with contradictory results. This study is a systematic meta-analytical review of experimental studies on the relationship between exposure to the glyphosate (GLY) and its formulations with the formation of micronuclei (MN) to establish a quantitative estimate of the environmental risks. The natural logarithm (ln) of the estimated response ratio was calculated from 81 experiments. A meta-analysis was performed on the complete data set, and individual meta-analyses were conducted after stratification by test system, class of vertebrate, exposure route, gender, endpoints, type of literature, formulation, GLY dose and exposure time. A forest plot showed an overall positive association between GLY exposure and its formulations and MN, corroborated by the cumulative effects size. Different responses were observed on mammalian and non-mammalian. Interesting results was noticed in exposure route where oral administration of GLY presented no significance. Exposure by intraperitoneal injection presented the highest MN formation. Pure GLY caused fewer effects than to commercial mixtures, but both presented mutagenic effects. The studies with males presented significant responses, while studies with females were not significant. The cumulative effects size was not clearly related to GLY dose, and was negatively related to exposure time. It can be attributed to different test systems, exposure routes and protocols analyzed. In conclusion, our results support the hypothesis that exposure to GLY and its formulations increases the frequency of MN formation.

In situ assessment of a neotropical fish to evaluate pollution in a river receiving agricultural and urban wastewater.

We aimed to assess the quality of a midsize river that receives agricultural and urban wastewater. Nuclear abnormalities (NA), comet assays of blood and gills, and gill histopathology were evaluated in fish Astyanax aff. paranae during the summer and winter 2011 at three sites in Paraná State, Brazil: (1) a biological reserve (Rebio-reference area); (2) an agricultural site; (3) a downstream site that accumulates agricultural and urban effluents. We found the highest effects of pollutants in fish at the downstream site during the summer. The agricultural site showed an intermediate damage rate, and fish at Rebio generally had the least damage, with the exception of NA. Despite conflicting results from the biomarkers used, we observed an increase in damage associated with the accumulation of pollutants. Pesticides are probable xenobiotics in the agricultural area. Additionally, metals and substances such as pharmaceuticals and ammonia may be present at the downstream site.

Using multibiomarker approach as a tool to improve the management plan for a Private Reserve of Natural Heritage (RPPN).

This study aimed to monitor an aquatic ecosystem during two different periods (dry and rainy season) on a protected area located inside a sugarcane farm, using the fish Astyanax sp. as bioindicator. An integrated approach was adopted by combining the responses of well-known biomarkers: acetylcholinesterase, lipid peroxidation (LPO), catalase (CAT), glutathione S-transferase (GST), micronucleus test, and liver histopathology. The activity of enzymes CAT and GST was increased after the rainy season. This can be explained mainly by the intensification of rain density, which drags substances into the streams, especially pesticides applied on agriculture. LPO and micronucleus test also suggested some effects of contamination in the surrounding area during this season. The results have supported a discussion about the effectiveness of protected areas in agricultural regions, emphasizing the biomonitoring as a tool for improving management plans in protected areas.

Uso de alterações morfológicas nucleares emAstyanax spp. para avaliação da contaminaçãoaquática / The use of nuclear morphologic alterations in Astyanax spp. forevaluating water contamination

No decorrer dos anos, os ecossistemas aquáticos têm sofrido grandes prejuízos, pois têm sido expostos a poluentes quecausam impactos ambientais irreversíveis, tanto em áreas urbanas como rurais. Nesse sentido, o presente trabalho foi realizadoem duas áreas urbanas da cidade de Guarapuava-PR e duas áreas rurais da cidade de Candói-PR, em 2013, comobjetivo de avaliar os impactos de diferentes fontes de poluição, quantificados por meio do teste de micronúcleo, usandocomo bioindicadores peixes do gênero Astyanax. Consistentes alterações na morfologia nuclear dos eritrócitos dos peixesforam visualizadas, com maior frequência na área mais urbanizada, a Lagoa das Lágrimas, e na área rural, o Alagado doRio Jordão. Esse último local é um rio de grande porte, que recebe grandes despejos industriais de efluentes advindos detoda a cidade de Guarapuava e de uma fábrica de reciclagem de papel, localizada muito próxima ao local de coleta. O rioCandoizinho, um local rural protegido por uma ampla mata ciliar, apresentou a menor taxa de dano, mostrando-se comoum local mais preservado. Um último ponto, localizado em um campus universitário semiurbanizado mostrou-se comouma taxa de alteração nuclear intermediária. Concluiu-se, então, que a poluição industrial e urbana pode causar danos àsaúde dos indivíduos que habitam corpos hídricos.

Over the years, aquatics ecosystem have been suffering great losses because of being exposed to pollutants that cause irreversibleenvironmental impacts, both in rural and urban areas. In this context, the present study was conducted in twourban areas of the city of Guarapuava (PR) and two rural areas of the city of Candói (PR) during 2013, aiming to assessthe impacts of different pollution sources. These impacts were quantified by micronucleus test, using fish individuals ofthe genus Astyanax as bioindicators. Consistent variations in nuclear morphology were identified in erythrocytes of fishes,more frequently in the most urbanized site, the Lagoa das Lágrimas, and in the rural area, the waterlogged in Jordão River.The latter site is a major river that receives effluents from the entire Guarapuava city and from a factory of recycling paper,located close to the sampled site. The Candoizinho River, a rural local protected by wide riparian vegetation, presented thelowest damage rate, being a preserved area. A last sampled site was located in a semi-urbanized area within a universitycampus. Organisms from this place showed intermediary damage rates. So, we concluded that industrial and urban pollutioncan cause irreversible damages to health of individuals inhabiting this water flow.

Evaluation of genotoxicity in Rhamdia quelen (Pisces, Siluriformes) after sub-chronic contamination with Fipronil.

Diverse genetic biomarkers have been used to evaluate the effects of pollution by mutagenic agents such as metals and pesticides, as well as a large variety of chemical substances derived from human activities. This work researched the effects that an exposure of 60 days to the insecticide Fipronil (concentrations of 0.05, 0.10 and 0.23 µg/L) can cause in the fish Rhamdia quelen using Comet assay with gills, histopathological analysis of gills and the Piscine Micronucleus test and Nuclear Morphological Alterations. The results for the Comet assay and for gills histopathological injuries showed no difference between the control group and the contaminated groups. In the Piscine Micronucleus test, the smallest concentration of Fipronil (0.05 µg/L) was similar as the control group, while concentrations of 0.10 and 0.23 µg/L caused more damage to the DNA. These results suggested that only the highest concentrations of Fipronil tested cause damage in erythrocytes, but none of these concentrations was sufficient to alter the DNA in the gill cells. R. quelen may be a less sensitive bioindicator than other fish that have been tested. On the other hand, the concentrations used may not have been sufficient to detect alterations in the DNA of R. quelen with the chosen tests. Works like this take on great importance given the enormous quantity of substances that are thrown daily into the environment in an uncontrolled way, without evaluation of the consequences. The application of these tests with other concentrations, tissues and exposure times is suggested for future works.