Brazilian Guidelines Research Articles

Comparison of postoperative chronic inguinal pain between the lichtenstein and laparoscopic techniques in the treatment of inguinal hernia: a systematic review and meta-analysis.

Currently, inguinal hernias are highly prevalent in the Brazilian population, accounting for 75% of all abdominal wall hernias. The recommended treatment to correct them is inguinal herniorrhaphy, which can be performed through open surgery, mainly using the Lichtenstein technique, or laparoscopically, primarily through Transabdominal Preperitoneal Repair (TAPP) or Total Extraperitoneal Repair (TEP) approaches. Like any surgery, these procedures have post-operative complications, with pain being the most common and debilitating. Currently, in European and Brazilian guidelines, the open Lichtenstein and endoscopic inguinal hernia techniques are recommended as best evidence-based options for repair of a primary unilateral hernia providing the surgeon is sufficiently experienced in the specific procedure. In that matter, the surgeon should make a choice based on assessment of the benefits and risks of performing each of them, and practice shared making decision with it patient. Therefore, the objective of this review was to assess the incidence of chronic postoperative pain by comparing the aforementioned surgical approaches to evaluate which procedure causes less disability to the patient. The search conducted untilMay 2024 was performed on Medline (PubMed), Cochrane (CENTRAL), and Lilacs databases. The selection was limited to randomized clinical trials, nonrandomized clinical trials and cohort studies comparing TAPP or TEP to LC, evaluating the incidence of chronic postoperative pain published between 2017 and 2023. Evidence certainty was assessed using the GRADE Pro tool, and bias risk was evaluated with the RoB 2.0 tooland ROBINS I tool. Thirteen studies were included. RESULTS: The meta-analysis showed a significant difference between the groups in both techniques, favoring the laparoscopic approach, which had a lower occurrence of postoperative inguinodynia with a relative risk of 0.49 (95% CI = 0.32, 0.75; I2 = 66% (P = 0.001); Z = 3.28 (P = 0.001) with low certainty of evidence. The presence of chronic postoperative pain was lower in laparoscopic TEP/TAPP techniques when compared to the open Lichtenstein technique, meaning that the former can bring more benefits to patients who requires inguinal herniorrhaphy. Nevertheless, further randomized clinical trials are needed to optimize the analysis, minimizing the bias.

Evaluating CO2 sequestration through Technosol constructed from coal mining waste

This paper proposes enhancing CO2 sequestration and recovering degraded areas using Technosols constructed with coal waste and strategic materials. The evaluation of carbon capture considered four methods: (i) plant dry mass produced by Megathyrsus Maximus cv. Mombasa (ii) carbon incorporation via biochar, (iii) microbial biomass carbon, and (iv) mineral sequestration by lime. Local soil from the mine site was used as a control. Results show soil fertility parameters of the Technosols according to Brazilian guidelines. Plant growth increased with biochar incorporation but was still lower than in control soil. The pH, chemical, and mineralogical composition data were combined with geochemical reactions, showing the interaction of coal waste compounds, mainly pyrite with lime. Regarding calculating the CO2 capture potential, biochar and mineral carbonation were the most relevant means for the designed system. The best performance obtained can capture approximately 65 t CO2eq ha−1, about four times greater than the systems traditionally used to recover waste disposal areas. The study demonstrates the feasibility of incorporating mining site recovery, waste disposal, and emissions mitigation in a closed system, providing sustainable options for the coal mining industry.

Are vegetarians’ diets inherently healthy? Ultra-processed food consumption is associated with overweight among vegetarians: the brazilian survey on the health, food, and nutrition of vegetarians

This cross-sectional study investigated ultra-processed food (UPF) consumption and its association with overweight among Brazilian vegetarian adults (n = 925). Data were collected using a self-administered structured online questionnaire. The prevalence of overweight was 26.2% (95% confidence interval [CI] 23.3–29.1). The median UPF consumption was 1.8 times/day (1.0–3.1 interquartile range [IQR]). The multivariable generalised linear model identified an increase in overweight probability as the UPF intake – categorised into quintiles – increases (prevalence ratio [PR] 1.08 [95%CI 1.01–1.17]). Additionally, age (PR 1.03 [95%CI 1.02–1.04]), eating more than three meals/day away from home (PR 1.56 [95%CI 1.08–2.23]), duration of vegetarianism (PR 0.98 [95%CI 0.97–0.99]) and living in the wealthiest regions in the country (PR 1.35 [95%CI 1.06–1.71]) were associated with overweight. Although vegetarians have a lower average UPF intake and overweight prevalence than the general population, UPF exposure can still lead to excessive weight gain or maintenance. This study endorses generalising the Brazilian Dietary Guidelines for the vegetarian population.

Factors Associated with the Practice of Low-Carb and Low-Fat Diets among Participants of the Longitudinal Study of Adult Health (ELSA-Brasil).

In the field of nutrition, both low-carbohydrate (LCD) and low-fat (LFD) diets were initially intended for specific subgroups but are now being embraced by the broader population for various purposes, including aesthetics and overall health. This study aims to assess sociodemographic, health, and lifestyle factors influencing diet choices among public servants in the ELSA-Brasil cohort. Diets were classified as LCD or LFD based on the Brazilian Diabetes Society (<45%) and WHO guidelines (<30%) respectively. A total of 11,294 participants were evaluated (45.3% men; 54.7% women) with a mean age of 52 ± 0.08 years. Having overweight, altered waist circumference, and a history of smoking confers higher chances of adopting an LCD compared to the usual diet, while being over 52 years, non-White race/skin color, in a lower income stratum, and having diagnosis of hypertension and/or diagnosis of diabetes mellitus decrease these chances. Regarding LFDs, belonging to the non-White race/skin color, being over 52 years old, being divorced, and practicing low physical activity decrease the chances of following such a diet compared to the usual diet. In conclusion, factors like age, socioeconomic status, health, and physical activity levels can be the key to understanding why individuals choose restrictive diets beyond clinical advice.

Brazilian Guideline for Exercise Testing in Children and Adolescents - 2024.

Classes de Recomendação Classe I: Condições para as quais há evidências conclusivas e, na sua falta, consenso geral de que o procedimento é seguro e útil/eficaz. Classe II: Condições para as quais há evidências conflitantes e/ou divergência de opinião sobre a segurança e utilidade/eficácia do procedimento. Classe IIa: Peso ou evidência/opinião a favor do procedimento. A maioria aprova. Classe IIb: Segurança e utilidade/eficácia menos estabelecidas, havendo opiniões divergentes. Classe III: Condições para as quais há evidências e/ou consenso de que o procedimento não é útil/eficaz e, em alguns casos, pode ser prejudicial. Níveis de Evidência Nível A: Dados obtidos a partir de múltiplos estudos randomizados de bom porte, concordantes e/ou de metanálise robusta de estudos randomizados. Nível B: Dados obtidos a partir de metanálise menos robusta, a partir de um único estudo randomizado e/ou de estudos observacionais. Nível C: Dados obtidos de opiniões consensuais de especialistas.

Effect of NaCl replacement on physicochemical and sensory properties of the traditional cured coppa

This study aimed to reduce sodium content in pork coppa without affecting consumer acceptance. NaCl reduction, partial replacement with KCl, and reduction in salting process time were evaluated. Six treatments were performed: Standard - 100% NaCl with a 2-day salting process and a 5-day re-salting process; T1 - a mixture of 70% NaCl/30% KCl; T2, T3, T4 - mixtures of 85% NaCl/15% KCl; T5 - 100% NaCl. T1 to T5 applied a 2-day salting process and a 2-day re-salting process. All treatments complied with Brazilian sodium guidelines. No statistically significant difference in consumer acceptance was observed. A reduction of 4 days in salting and re-salting processes maintained sensory characteristics and reduced sodium content by 50%. Even with reduced salt content, no changes in physicochemical parameters or effects on product preservation and microbiological quality were observed. NaCl reduction and replacement up to 30% KCl did not affect coppa characteristics or acceptance.

Development of mental health first aid guidelines for psychosis for Brazil: A Delphi expert consensus study.

Psychotic symptoms can be highly debilitating for those experiencing them. Community members, including family and friends, can play a crucial role in providing support to a person during the early stages of psychosis, provided they have the necessary resources. Mental health first aid guidelines for psychosis have been developed for high-income countries and this study aimed to adapt those guidelines for Brazil. A Delphi expert consensus method was used to gather the views and opinions of 28 health professionals and 24 individuals with lived experience of psychosis in Brazil over two survey rounds. Firstly, 403 statements were translated from English to Brazilian-Portuguese. In the Round 1 survey, participants were asked to rate each statement based on how important they believed it was for it to be included in the Brazilian guidelines. They were also asked to suggest new actions if they wished. Consensus was reached on 257 statements. Eight new statements were created and endorsed from panelists' comments, and a further 45 statements were unique to the Brazilian guidelines. There was a modest level of similarity between the English-language and Brazilian guidelines. However, the Brazilian guidelines had a greater focus on the importance of family support for people with psychosis and stigma as a possible barrier for openly discussing help-seeking actions for mental health problems in Brazil.

Differences in the cost and environmental impact between the current diet in Brazil and healthy and sustainable diets: a modeling study

BackgroundWhile healthy and sustainable diets benefit human and planetary health, their monetary cost has a direct impact on consumer food choices. This study aimed to identify the cost and environmental impact of the current Brazilian diet (CBD) and compare it with healthy and sustainable diets.MethodsData from the Brazilian Household Budget Survey 2017/18 and the Footprints of Foods and Culinary Preparations Consumed in Brazil database were used for a modeling study comparing the cost of healthy and sustainable diets (based on the Brazilian Dietary Guidelines (BDG) diet and the EAT-Lancet diet) versus the CBD. The DIETCOST program generated multiple food baskets for each scenario (Montecarlo simulations). Nutritional quality, cost, and environmental impact measures (carbon footprint (CF) and water footprint (WF)) were estimated for all diets and compared by ANOVA. Simple linear regressions used standardized environmental impacts measures to estimate differentials in costs and environmental impacts among diets scenarios.ResultsWe observed significant differences in costs/1000 kcal. The BDG diet was cheaper (BRL$4.9 (95%IC:4.8;4.9) ≈ USD$1.5) than the CBD (BRL$5.6 (95%IC:5.6;5.7) ≈ USD$1.8) and the EAT-Lancet diet (BRL$6.1 (95%IC:6.0;6.1) ≈ USD$1.9). Ultra-processed foods (UPF) and red meat contributed the most to the CBD cost/1000 kcal, while fruits and vegetables made the lowest contribution to CBD. Red meat, sugary drinks, and UPF were the main contributors to the environmental impacts of the CBD. The environmental impact/1000 kcal of the CBD was nearly double (CF:3.1 kg(95%IC: 3.0;3.1); WF:2,705 L 95%IC:2,671;2,739)) the cost of the BDG diet (CF:1.4 kg (95%IC:1.4;1.4); WF:1,542 L (95%IC:1,524;1,561)) and EAT-Lancet diet (CF:1.1 kg (95%IC:1.0;1.1); WF:1,448 L (95%IC:1,428;1,469)). A one standard deviation increase in standardized CF corresponded to an increase of BRL$0.48 in the cost of the CBD, similar to standardized WF (BRL$0.56). A similar relationship between the environmental impact and the cost of the BDG (CF: BRL$0.20; WF: BRL$0.33) and EAT-Lancet (CF: BRL$0.04; WF: BRL$0.18) was found, but with a less pronounced effect.ConclusionsThe BDG diet was cost-effective, while the EAT-Lancet diet was slightly pricier than the CBD. The CBD presented almost double the CF and WF compared to the BDG and EAT-Lancet diets. The lower cost in each diet was associated with lower environmental impact, particularly for the BDG and EAT-Lancet diets. Multisectoral public policies must be applied to guide individuals and societies towards healthier and more sustainable eating patterns.

Cardiovascular Risk, Statin Use and Electrocardiogram in HIV Patients

Introduction: Non-infectious complications became more frequent in patients living with the Human Immunodeficiency Virus (HIV). Dyslipidemia is common and represents an important cardiovascular risk factor in this population. Therefore, cardiovascular diseases represent one of the main causes of HIV morbidity and mortality. Objective: This study aimed to assess cardiovascular risk and electrocardiographic changes in outpatients living with HIV. Methods: We performed a single-center cross-sectional study that included HIV patients who were at least 30 years old and had HIV diagnosis for more than one year. Patients were on regular follow-up in a tertiary center in Brazil. Cardiovascular risk was assessed using the Global Risk Score (GRS), as recommended by Brazilian guidelines. Cardiovascular risk factors, lipid profile, statin use and resting electrocardiogram were also analyzed. Results: 92 patients were included, with an average age of 48.9 years. 54 (58.7%) were male, 28 (30.4%) had hypertension, 10 (10.9%) had type 2 diabetes mellitus, 9 (9.8%) were current smokers, and 25 (27.2%) had a previous diagnosis of dyslipidemia. Average LDL-cholesterol level was 120.2 ± 40.6 mg/dl. Eleven patients (11.9%) were on statin therapy. High cardiovascular risk was identified in 28 patients (30.4%) and only seven of those (25.0%) were on statin therapy. Serum LDL-cholesterol higher than or equal to 130 mg/dl was found in 31 patients (33.7%), and only seven of those (22.6%) were on statin therapy. ECG changes were found in 21.7%, mostly due to conduction disturbances (17.4%). Conclusion: We found a high prevalence of HIV outpatients with high cardiovascular risk. Only one in every four patients with this characteristic was on statin therapy. Cardiovascular risk is one of the main concerns in the HIV population, once antiretroviral therapy succeeds to reduce mortality attributed to opportunistic infections.

Self Organizing Maps (SOM) and statistical methods for describing the physicological profile of undergraduates students of engineering

To meet a Brazilian guideline for engineering courses, which advocates the use of active learning in applied disciplines, this research studies new students entering in the Metallurgical Engineering Course in Escola Politécnica of Universidade de São Paulo (PMT/USP). It was applied to them a traditional MTBI (Myers–Briggs Type Indicator) questionary with the aim of finding out if there is recurrence of psychological profiles and to understand the characteristics of the freshmen to learning. This information was subjected to statistical analysis to observe the recurrence of the psychological characteristics of freshmen over the years (2017 to 2021). The data was also subjected to the Self Organizing Maps (SOM) machine learning technique, to delineate and group the psychological profiles observed in the students, enabling the analysis of the psychological characteristics and the comparison with the results obtained via statistics. After that, the results from the MBTI Traditional and the SOM clustering were submitted to comparison methods through multivariate statistics and Multiple Correspondence Analysis (MCA). It was found that there is recurrence of psychological characteristics between the years of collection, what were the psychological profiles of these freshmen as to how they learned. It was found that the freshmen surveyed mostly belong to Generation Z (or iGen) and characteristics pertinent to this group were observed. A scenario is obtained to point out the best active learning techniques for these students with the verification of recurrence of profiles and other correlated psychological characteristics, aiming to provide the most effective teaching in the engineering course.

Spectrum of germline pathogenic variants in Brazilian hereditary breast/ovarian cancer cases.

To define the spectrum of germline pathogenic variants (PVs) and copy number variant (CNV) in cancer susceptibility genes to the burden of breast and ovarian cancer (BC, OvC) in high-risk Brazilians in Minas Gerais with health insurance, southeast Brazil, undergoing multigene panel testing (MGPT). Genotyping eligible individuals with health insurance in the Brazilian healthcare system for Hereditary Breast and Ovarian Cancer Syndrome to undergo molecular testing for 44 or 141-gene panels, a decision that was insurance driven. Overall, 701 individuals clinically defined as high BC/OvC risk, underwent MGPT from 1/2021 to 10/2022, with ~ 50% genotyped with a 44-gene panel and the rest with a 141-gene panel. Overall, 16.4% and 22.6% of genotyped individuals harbored PVs using 44-gene and the 141 gene panel, respectively. The most frequently mutated genes were: BRCA2 (3.7%); BRCA1 (3.6%) and monoallelic MUTYH (3.1%). The rate of PVs detected in high-risk individuals in this study was twice the 10% threshold used in Brazilian health guidelines. MGPT doubled the detection rate of PVs in cancer susceptibility genes in high-risk individuals compared with BRCA1/BRCA2 genotyping alone. The spectrum of PVs in Southern Brazil is diverse, with few recurring variants such as TP53 (0.6%), suggesting regional founder effects. The use of MGPT in hereditary cancer in Minas Gerais significantly increased the detection rate of P/LPVs compared to existing guidelines and should be considered as the primary genotyping modality in assessing hereditary cancer risk in Brazil.

Response to the letter to the editor Fibrosis or steatosis: which is the best screening target? Comment on the Brazilian evidence-based guideline for screening, diagnosis, treatment, and follow-up of metabolic dysfunction-associated steatotic liver disease (MASLD) in adult individuals with overweight or obesity.

Response to the letter to the editor Fibrosis or steatosis: which is the best screening target? Comment on the Brazilian evidence-based guideline for screening, diagnosis, treatment, and follow-up of metabolic dysfunction-associated steatotic liver disease (MASLD) in adult individuals with overweight or obesity.

Fibrosis or steatosis: which is the best screening target? Comment on the Brazilian evidence-based guideline for screening, diagnosis, treatment, and follow-up of metabolic dysfunction-associated steatotic liver disease (MASLD) in adult individuals with overweight or obesity.

Fibrosis or steatosis: which is the best screening target? Comment on the Brazilian evidence-based guideline for screening, diagnosis, treatment, and follow-up of metabolic dysfunction-associated steatotic liver disease (MASLD) in adult individuals with overweight or obesity.

Methodological guidelines and publications of benefit–risk assessment for health technology assessment: a scoping review

ObjectivesTo map the available methodological guidelines and documents for conducting and reporting benefit–risk assessment (BRA) during health technologies’ life cycle; and to identify methodological guidelines for BRA that could serve...

Diagnosis and management of acute promyelocytic leukemia: Brazilian consensus guidelines 2024 on behalf of the Brazilian Association of Hematology, Hemotherapy and Cellular Therapy

Improvements in clinical assessment have occurred since the last published recommendations on the diagnosis and treatment of acute promyelocytic leukemia in 2013. Here, a committee of specialists of the Brazilian Association of Hematology, Hemotherapy and Cellular Therapy presents a comprehensive review on the current knowledge, focusing on the advances in diagnosis, risk assessment, and frontline and salvage therapy. The concept of urgent diagnosis is explored as well as the management of critical situations such as coagulopathy and differentiation syndrome. Recent adjustments in risk stratification based on white blood cell counts only are presented together with the incorporation of chemo-free regimens for non-high-risk patients. Special conditions such as acute promyelocytic leukemia in children, the elderly and pregnant women are discussed. Finally, acute promyelocytic leukemia is presented as a highly curable disease because of the real possibility of targeted therapy towards differentiation, and, paradoxically, as a serious and urgent condition that deserves prompt recognition and management to avoid early mortality.

The use of epibenthic copepod Tisbe biminiensis nauplii to assess the toxicity of seawater samples in Suape Bay (state of Pernambuco; Brazil)

Bioassays to determine the toxicity of water have been used worldwide as a tool of environmental monitoring. In the present study, the epibenthic copepod Tisbe biminiensis nauplius is proposed as a test organism for samples of seawater. Survival and the percentage of development from nauplius to copepodite were compared to the embryo-larval development of the sea urchin L. variegatus exposed to the same samples from the Suape estuarine system (state of Pernambuco, Brazil) collected in 2009. T. biminiensis naupliar development displayed a similar sensitivity to that found with the sea urchin embryos, mainly when simple t-test (not bioequivalent corrected) was used for sea urchin data. However, a lower sensitivity of copepod survival was found. The aluminium, iron and lead concentrations in surface waters were sometimes higher than Brazilian guidelines for estuarine water, probably due to dredging activities and anthropogenic contamination. These metals could be at least partially responsible for the toxic effects found at different stations and months. The results indicated that naupliar development of this epibenthic copepod is appropriate for the assessment of toxicity levels in seawater samples.

Aflatoxin and microbial safety in commercial confectionery peanut paçoca produced in São Paulo state – Brazil

Paçoca is a typical Brazilian confectionery of Indigenous origin prepared by mixing ground roasted peanuts, sugar, and salt. A total of 52 samples of paçoca (37 pressed, 15 cooked), produced and sold in the state of São Paulo, were evaluated for aflatoxin content (AFB1, AFB2, AFG1 and AFG2), moisture content and water activity. The microbiological quality was assessed by counting mesophilic aerobic bacteria, fungal and yeast counts, most likely number of thermotolerant coliforms and Escherichia coli and Salmonella sp. The limit of quantification (LOQ) by Ultra Performance Liquid Chromatography coupled to the Mass Spectrometer (UPLC-MS/MS) ranged from 0.29 μg kg−1 for AFB1 and AFG2; 0.36 μg kg−1 for AFG1 and 0.37 μg kg−1 for AFB2. The recovery averages were 89.2, 83.5, 80.5 and 82.8% for AFB1, AFB2, AFG1 and AFG2. 71% of the samples showed aflatoxin contamination, ranging from 0.29 to 38.8 μg kg−1 (mean of 7.06 μg kg−1). Six samples (16%) exceeded the limit value tolerated by the Brazilian guideline for AFT (20 μg kg−1). The mean AFT content in cooked paçocas (19.55 μg kg−1) was higher than the levels in pressed paçocas (9.08 μg kg−1) (p < 0.05). AFB1 had a higher incidence in the two groups of paçocas (75% pressed and 60% cooked). The mean moisture content and water activity of cooked paçocas (8.86% and 0.7081) were higher than those of pressed paçocas (2.08% and 0.4863). Twenty-one samples (56%) showed fungal and yeast contamination ranging from 1.0 to 4.25 log CFU g−1. The total count of aerobic mesophilic bacteria in cooked paçocas (4.85 log CFU g−1) was also higher than in pressed paçocas (2.77 log CFU g−1) (p < 0.05). E. coli was confirmed in these samples in the range of 3.0–160 NMP g−1. Salmonella sp. was detected in 2 samples of pressed paçocas, indicating poor hygiene, inefficient heat treatment or possible cross-contamination. The results of this study demonstrate the need for greater control of the paçoca production chain through the adoption of Good Manufacturing Practices and process control, to prevent exposure of the population to aflatoxins and possible pathogenic microorganisms.

Aetiological molecular identification of sexually transmitted infections that cause urethral discharge syndrome and genital ulcer disease in Brazilian men: a nationwide study

BackgroundLittle is known about the aetiology of urethral discharge syndrome (UDS) and genital ulcer disease (GUD) in Brazil due to limited access to laboratory tests and treatment based mainly on...

Guideline Adherence and Outcomes of Patients with Candidemia in Brazil.

Candidemia is a significant cause of mortality among hospitalized patients, both worldwide and in Brazil. Prompt and appropriate treatment are essential to mitigate mortality, and clinical practice guidelines aim to optimize patient care based on the best scientific evidence. This study aims to examine the management of candidemia, assessing adherence to the guidelines of the Brazilian Society of Infectious Diseases in a single center located at São Paulo, Brazil. All adult patients hospitalized from 2016 to 2018 who presented one positive blood culture for Candida spp. were included. Electronic medical records were retrospectively reviewed to collect information relevant to the treatment for candidemia, in order to assess the adherence to the Brazilian guideline for the management of candidemia in relation to nine defined outcomes, and we correlated those findings with 30-day mortality by using uni- and multivariate analyses. A total of 115 patients were included; 68 patients (59.1%) were male, with a mean age of 55 years. C. albicans, C. tropicalis and C. glabrata were the most prevalent species. In total, 80 patients (69.5%) received antifungal treatment. The adherence to Brazilian guideline recommendations was determined as described in the following: initial treatment with echinocandin in 48 (60%); step-down to fluconazole in 21 (26.2%); collection of first control blood culture in 43 (58.9%); collection of second control blood culture, if the first one had been positive, in 14 (73.6%); treatment for 14 days after the first negative blood culture in 53 (65.4%); central venous catheter (CVC) removal in 66 (82.5%); CVC removal if the first control blood culture had been positive in 17 (89.4%); performance of a transthoracic echocardiogram in 51 (63.7%) and performance of a fundoscopy in 59 (73.7%). Univariate analysis showed that CVC removal and initial echinocandin therapy were more prevalent in the surviving group, but with no statistically significant difference. On the other hand, step-down to fluconazole demonstrated higher survival rate in the multivariate analysis OR 0.15 (95% CI 0.03-0.8); p = 0.02. The analysis of these nine recommendations demonstrates that it is necessary to improve adherence to specific recommendations and also disseminate strategies of the initial use of echinocandin as the drug of choice and addressing length of treatment and follow-up and complementary exams. Our study provides reassurance that the step-down to fluconazole is safe and may be recommended, if the preexisting conditions are present.

Hydrochemistry and Contamination in Sedimentary and Fractured-Rock Aquifers of The Upper Rio Negro Basin – Amazonas/Brazil

The Amazon region has the largest hydrographic network on the planet. However, cities and communities along rivers obtain water from tube wells without studying the chemical quality and, consequently, the potability of their water. In specific geological contexts, there is a significant probability of natural contamination by arsenic in groundwater in the region, already attested in previous works in the Solimões, Madeira and Amazonas rivers basins, but not yet found in the Negro river basin. As the Negro is the second largest river in the Amazon Basin, it has become necessary to study the chemical quality of its groundwater, relating it to the geology of the region. In this work, water samples were collected from 21 wells and 4 water springs used for human consumption, following the protocols proposed by the US – EPA. In the field, the physicochemical parameters of the in-situ water were measured, and alkalinity tests were carried out on the samples. The cations were analyzed at INPA and the anions at the Geological Survey of Brazil (SGB). From the 25 samples, 16 had analises results within acceptable ionic balance values, and 12 of the 16 had at least one of the following elements in concentration above World Health Organization and Brazilian Guideline Values: Al, As, Fe, Mn and Pb. The presence of values below the GV, but above what is considered natural, of NO3- in 66% of the contaminated points, associated with the shallow depth of most of the wells, installed in areas of recent sedimentary deposits and that do not show any or few signs of care demonstrate that the contamination in these localities is of anthropic origin. Two samples (16% of the contaminated samples) are from deep wells installed in fractured aquifers, which in this case indicate contamination of geogenic origin. Arsenic was found in association with iron and aluminum in a well installed in alluvial sediments, which indicates that more studies are needed for this specific geologic formation to know the quality of this water. For other locations and cities, short, medium and long-term measures are needed to prevent anthropogenic contamination of aquifers.