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Introduction. In Peru, municipal solid waste in 2021 reached 8,215,355.9 tons and only 61.28 % is disposed of in sanitary landfills to be treated through composting; however, its implementation is deficient and requires studies to obtain a usable product as a substrate or amendment and reduce environmental pollution. Objective. The study determined the levels of nutrients, heavy metals, fecal microorganisms, and the quality of compost based on solid urban organic waste produced at the Shapajilla Valorization Plant in the Leoncio Prado province of Peru. Materials and methods. Four piles of organic solid waste were composted and evaluated for nutrients, heavy metals, fecal microorganisms, and quality based on Chilean Standard 2880 and Spanish Standard 824. Results. 95 % of the composted materials were food waste, fruit and peelings, and there were no differences between the piles evaluated. During processing, the temperature reached the different stages and the pH increased. High pH levels (>7.50) and low levels of Ca, Mg and K (< 1 %) were found; heavy metals presented differences and low levels, with absence of microorganisms of fecal origin, and the composts were of intermediate quality (B). Conclusions. The compost produced is of intermediate quality, free of metals and pathogenic microorganisms, and can be used as a substrate or amendment with some limitations, due to the high pH levels and low levels of Ca, Mg and K. [ABSTRACT FROM AUTHOR]

User demographics, perceptions, and motivation data obtained from actual observation and experience surveys provide contextualized and first-hand information for game designers. However, this type of information can be misinterpreted if it is presented as numbers. Contextual Design (CD) is a user-centered method that allows a better understanding of the user’s work environment, as well as the requirements that the interactive systems must have to cover their needs. According to the CD, the user Personas (also called archetypes) are representations of users created to establish behaviors, likes and motivations of a representative group of users who share common patterns. These types of profiles can represent user groups during the design and development process of a videogame, thus allowing a more focused design. This paper describes step by step the process of designing user Personas for a group of 25 participants with stroke. This information was obtained from contextual interviews and gaming experience surveys, which allowed a more homogeneous interpretation of the dislikes, limitations and motivations of the participants. The CD methodology showed to be very useful, generating four user profiles, which were used for the creation of a serious video game in virtual reality that allows therapeutic support in a physical rehabilitation process for people with stroke. Finally, this work presents the preliminary design of the videogame and the importance of the information in the creation of user models. [ABSTRACT FROM AUTHOR]

Lead (Pb) is a heavy metal considered one of the major soil pollutants. Phytoremediation is a sustainable and economically viable biological method for reducing Pb content in the environment. Inga uruguensis is a tree legume species that has characteristics favorable to phytoremediation, such as rapid growth and high biomass production. The objective of this work was an initial evaluation of tolerance and phytoremediation potential of I. uruguensis to Pb. The experiment was carried out in a greenhouse. In addition to the control, soil contamination was carried out with the following Pb doses: 100, 200, 300, 400, and 500 mg.dm?, with 5 repetitions in each treatment, totaling 30 vases. We assessed growth, number and mass of nodules, chlorophyll content, ureids, amino acid, protein and soluble carbohydrates in leaves, roots and nodules, tolerance index, dry matter, and tissues Pb content of I. uruguensis. The data were analyzed by the Tukey test using R and SISVAR software. There was no negative effect of Pb in soil on I. uruguensis growth, the symbiotic relationship with rhizobia was kept, even at high Pb content and the tolerance index was not lower than 0.69. Inga uruguensis has initial tolerance and potential to be used as phytoremediation in soils contaminated by Pb. [ABSTRACT FROM AUTHOR]

O ne of the main metals explored in the world is copper (Cu), a native element, which is rarely found pure in nature. The mining and processing of copper generates environmental debates due to the generation of polluting agents in the areas of concentration, smelting and refining, in addition to the negative impacts imposed on the vegetation and topography of the mined area. The study aimed to investigate the initial morphometric performance of the white ipe (Tabebuia roseo-alba (Ridl.) Sandwith) in a substrate composed of copper mining tailings and increasing percentages of organic matter, evaluate its phytoremediator potential and the Dickson's Quality Index (IQD). The experimental design was the entirely randomized one. Morphometric data of the treatment were collected regarding height, stem diameter and number of leaves of the plant species where they were later submitted to statistical and IQD analysis, in addition to calculations related to the index and translocation factor of copper in the plant and its phytoextracting capacity. The phytomass compartmentalized in roots and aerial part was collected, placed in a drying oven, ground and sent to the laboratory for the proper evaluation of the copper metal in the compartments of the plant species, in addition to the chemical evaluation of the substrate. It was concluded that white ipe has the potential to phytostabilize the copper element coming from mining tailings, as well as achieving a satisfactory IQD in treatment composed of 90% of mining tailings and 10% of organic matter. [ABSTRACT FROM AUTHOR]

This research evaluated the phytotoxic effects of cadmium on the germination development and initial growth of Gossypium hirsutum L. The ecotoxicological effects of 13 experimental concentrations of cadmium (0.0-50.0 mM) on variables like germination percentage, GSI, average germination time (AGT) and root length were evaluated. G. hirsutum seeds exposed to cadmium showed a decrease in germination percentage and an increase in the number of normal plantules from the concentrations 18.0 and 3.0 mM, respectively. It also inhibited root growth and increased the AGT from the exposure to the concentration 0.5 mM, reducing the GSI. G. hirsutum is tolerant to cadmium during its germinal stage. [ABSTRACT FROM AUTHOR]

This study uses the experimental research by phytoremediation technique, with the use of Canavalia ensiformis as a soil phytoremediation contaminated by slag, the analysis was done in five treatments under different doses of the contaminant (0, 32, 64, 128 and 256 grams). The results were submitted to analysis of variance and the means compared by 5% Tukey test. It can be concluded that the plant growth pattern was affected by the contaminant and the treatment 02 showed further development of the branch and biomass production compared to the others, and the Treatment 04 had lower branch growth rate followed by lower production biomass compared to other witnesses. [ABSTRACT FROM AUTHOR]

Understanding the effects of heavy metals in aquatic ecosystems is of significant importance due to their potential to bioaccumulate at various trophic levels and induce damage in DNA. Mercury is considered one of the most dangerous heavy metals, causing chromosomal breakage (clastogenic event) or spindle dysfunction (aneugenic event), that can lead to the formation of encapsulated chromatin into a separate smaller nucleus, generally referred to as a micronucleus. We evaluated the sensitivity of the micronucleus test in the neotropical cichlid Andinoacara rivulatus (Günther 1860). The fish were divided into four groups of 16 individuals, and each group was placed in separate aquaria (140 L) provided with filtered water and constant aeration. Fish were exposed to mercury chloride (HgCl2) at doses 0.1, 0.25, and 0.50 mg/kg body weight, administered by intraperitoneal (IP) injection. Fish from the control group were injected with a physiologic solution. The following erythrocyte anomalies were identified: erythrocytes with micronuclei varying to some extent in size and position in the cytoplasm, blebbed nucleus, binucleated cell, nuclei showing a deep invagination toward the center (notched nuclei). Examination of blood smears demonstrated a higher level of micronucleus and notched erythrocytes in fish injected with HgCl2 than in the controls. There were significant differences in the frequency of micronucleated and notched erythrocytes among the groups exposed to mercury. Linear regression analysis revealed a positive relationship between the frequency of micronucleated and notched erythrocytes (P< 0.0001), with a moderately strong correlation coefficient (R= 0.737). We propose that, in addition to the two so far known mechanisms of micronucleus formation (spindle apparatus damage and chromosomal ruptures), chromatin fragmentation in notched nuclei resulting from a combination of the cytotoxic effects of mercury and mechanical stress, may be a third mechanism of micronuclei genesis. [ABSTRACT FROM AUTHOR]

The presence of arsenic in irrigation water and its accumulation in agricultural soil increases in areas with intensive farming and negatively affects the health and economy of the producers. Plants absorb arsenic in the form of arsenate and can translocate it to the seeds; thus, we can find arsenate in the flour of species like wheat (Triticum durum). The plant cellular mechanisms do not differentiate phosphorous from arsenic due to the similarity between them; this generates metabolic disorders that restrict the plant development and its physiological performance from its first phenological stages, and can even limit the productive plot establishment. This study aimed to evaluate the physiological modifications and antioxidant components due to arsenate in wheat seedlings. We hypothesized that the response depends on the concentration of arsenate and the tolerance of the varieties. In the Bárcenas and Cortázar varieties seedlings, we evaluated concentrations of arsenate (100, 200, 500, and 700 mg L-1) and distilled water, using a randomized complete block experimental design. We considered each variety as a block and the treatments corresponded to the block combinations with the concentrations of arsenate and the control, with five repetitions per germination test. The Bárcenas seedlings were the most vigorous and presented the highest antioxidant activity, and with high concentrations of arsenate they synthesize greater concentrations of proline and phenolic compounds. With this variety, it could be possible to obtain tolerant lines that allow the cultivation of wheat plants in high concentrations of arsenic. [ABSTRACT FROM AUTHOR]

Introduction: Metals are called the chemical elements on the left and center of the periodic system. They are simple, solid elements (except mercury), conductors of heat and electricity, with a special shine once polished, and crystalstructure in solid state. Lead (Pb) is a heavy metal, which belongs to subgroup IV B of the periodic table and is the 82nd element. It has an atomic mass of 207.19 and its usual state of oxidation in inorganic compounds is +2. Acute poisoning is not common, the chronicism is called Saturnism: derived from the ancient name of the Pb "Saturn". The toxicity of this metal was recognized by Nicander of Colofon in 200 BC, with B. Ramazini in 1700 the first to study it. No benefit is known for the organism and is neurotoxic. Objective: Describe lead poisoning, as well as sources of exposure, clinical manifestations, preventive and pharmacological treatment. Methods: A bibliographic review was conducted on lead poisoning based on a telephone consultation carried out by professionals of the Pedro Soto Alba Pediatric Hospital to the Medical Guard of the National Center of Toxicology, by a patient diagnosis of lupus poisoning. [ABSTRACT FROM AUTHOR]

Phytoremediation is an alternative technique used to treat copper-contaminated soils. The objective of this research was to explore the behavior of nine summer cover crops regarding the growth, absorption and translocation of copper in soils with contamination levels exceeding the Value of Prevention, with a view to selecting plants for phytoremediation programs. In the experiments the Cambisol was contaminated with copper, added in doses of 0, 100, 200, 400, 500 and 600mg kg-1, in which the following nine plants were cultivated under greenhouse conditions: Canavalia ensiformis, Cajanus cajan, Dolichos lablad, Mucuna cinereum, Mucuna aterrima, Crotalaria juncea, Crotalaria spectabilis, Pennisetum glaucum and Paspalum notatum. At 90 days after sowing the plants were evaluated for dry mass of shoot and root, Cu, N, P, K, Ca, Zn, and Fe levels in the shoot and Cu in the roots. High soil Cu levels induced a decline in the phosphorus absorption by the plants. Canavalia ensiformis displayed high potential for phytoextraction as these plants could translocate high copper concentrations to the aerial plant parts, while the Mucuna cinereum and M. aterrima are indicated for the copper phytostabilization programs, due to the high copper accumulation in their root systems. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present the development and application of a method to estimate the heavy metal (HM) contribution derived from the wash-off by runoff on road-deposited sediments (RDS) in a high-altitude megacity (Bogota, Colombia). The method is based on the development of a HM wash-off equation which considers two processes: HM transportation and HM leaching. HM contribution by runoff ranges between 24.7% and 50.3%, relative to the total mass per unit area of HMs associated with dry-weather RDS (Mn, Cd, As, Zn, Cu, Ba, Pb, and Fe). The HMs that show a greater contribution are Cd, Zn, and Mn. RDS size fraction below 250 µm contributes on average 81.6% of the total HM load washed-off by runoff. The findings suggest that the RDS size fraction below 250 µm must be the reference fraction for the control systems design of HM pollution in Bogota city. [ABSTRACT FROM AUTHOR]

Lead is one of the most toxic heavy metals for living beings, which is a problem on a global scale. This metal is found naturally in the environment. It can remain for long periods in animal tissues, and produce physiological and behavioral alterations, even death. One of the most affected taxonomic groups are birds, especially those species that are at the top of the food chain, due to their susceptibility to the bioaccumulation of heavy metals. However, in South America, there is little information on lead exposure in birds from the New World vulture (Cathartidae) family. This research aimed to determine basal concentration levels of lead in birds from the Cathartidae family kept in captivity conditions in Colombia. To the effect, blood samples of nine king vultures (Sarcoramphus papa) and seven Andean condors (Vultur gryphus) were analyzed from three zoos using atomic absorption spectrophotometry. The results suggest that 15 out of 16 specimens contain blood lead concentrations. Zoo B had the highest average (2.65 ± 1.00 μg/dL), followed by Zoo C (1.87 ± 0.63 μg/dL), and zoo A (0.8 ± 0.89 μg/dL). The average for S. papa was 2.11 ± 0.42 μg/dL, while for V. gryphus it was 1.89 ± 1.52 μg/dL. It is concluded that although there is a significant difference (p = 0.01) among the sampled zoos, and lead concentrations were detected in 93.75% of the population, these are low compared to levels reported by other studies. [ABSTRACT FROM AUTHOR]

Soils which are cultivated with grapevines have high available copper (Cu) content, which can be toxic to cover crops cohabiting vineyards, such as black oats. This study aimed to assess the effect of liming in reducing Cu toxicity in black oats grown in sandy soils. Samples of a Typic Hapludalf were collected at 0-20cm, dried and subjected to the addition of Cu (0 to 50Mg kg-1) and limestone (0, 1.5, and 3.0Mg ha-1). The soil was placed in a rhizobox and black oats were grown for 30 days. We assessed root and shoot dry matter production, copper (Cu), calcium (Ca) and magnesium (Mg) contents in the tissues; Cu content in the root symplast and apoplast, as well as Cu, carbon and pH values in the rhizosphere and bulk soil. Liming reduced Cu toxicity in black oats. Cu was preferentially accumulated in the roots, mostly in the apoplast, which may be the result of a plant tolerance mechanism to prevent the transport of Cu to the shoots. [ABSTRACT FROM AUTHOR]

Background: Lead poisoning is one of the major toxic diseases of cattle. Contamination occurs with ingestion of products containing lead, especially batteries, or through contaminated pastures and water sources. Clinical signs are neurological and necropsy findings and histopathological changes may vary depending on the clinical presentation. Although the disease is widely reported in the literature, there are rare descriptions of intoxication in cattle raised in military training areas. This work describes the epidemiological, clinical and anatomopathological features of an outbreak of lead poisoning in cattle kept in a military artillery training camp. Case: Fifteen cattle out of a herd of sixty 4-6 year-old, mixed breed castrated males were affected. The cattle were held in a 100 ha of native pasture used for military artillery training. After three weeks in this area, the affected cattle had predominantly neurological clinical manifestations, characterized by somnolence, ambulatory incoordination, muscle tremors, bruxism, aimless walking, blindness and decubitus. The clinical course was 24-72 h. Eight of the 15 affected cattle died and two were necropsied. Necropsy finds were non-specific and the histological lesions of both necropsied cattle were restricted to the brain and kidneys. Laminar neuronal necrosis, neuropil vacuolization (spongiosis) and vascular endothelial hypertrophy were observed in the telencephalic cortex. Additionally there was astrocytic degeneration and neuronophagia. There was degeneration and necrosis of renal tubular epithelium and in one bovine there were intranuclear inclusion bodies in the renal epithelial cells; these inclusion bodies were highlighted using both modified Ziehl-Neelsen and periodic acid Schiff (PAS) stains. The levels of lead found in the kidneys and livers of the two necropsied cattle were respectively 51.7 μg/g and 41.00 μg/g for one of the necropsied cattle; and 431μg/g and 39.0 μg/g for the other. After the diagnosis of intoxication, cattle were removed from the area and the remaining seven affected bovines recovered. Discussion: The diagnosis of lead poisoning in cattle in the current study was based on epidemiological, clinical, anatomopathological data and in the determination of lead levels in the kidney and liver. The association of these data provides an invaluable aid in confirming a presumptive diagnosis of lead poisoning. Pasturing on military artillery training fields is a rarely described form source of lead for the intoxication in bovine species. In such cases, cattle may ingest the lead directly from the soil or through contaminated pastures containing lead dust on the surface of the leaves. Histologically, laminar neuronal necrosis in the telencephalic cortex, associated with tubular necrosis and intranuclear inclusion bodies in tubular epithelial cells, are characteristic features of the intoxication. These changes are usually associated with ischemic anoxia in the nervous system and alteration in nuclear function which interferes in gene expression in the kidney. Lead poisoning in cattle should be differentiated from other neurological conditions, especially rabies, hepatic encephalopathy and several causes of polioencephalomalacia. Areas of military artillery training are unfit for the development of agricultural exploitation activities, as they represent potential sources of contamination for livestock. [ABSTRACT FROM AUTHOR]

An exhaustive literature review aimed at demonstrating the existent relationship between certain professions and poisonings due to heavy metals was carried out. To such effects, the emission sources and uses of these metals are described in this work, as well as the disorders damaging health. It was verified that the poisonings diagnosed in workers of the province, during 2000-2016, were associated with different jobs, such as batteries repair, plumbing, welding and dentistry. From the above-mentioned, some recommendations to consider everything regarding occupational health-heavy metals are exposed. [ABSTRACT FROM AUTHOR]

Earth mounds fields are wetlands characterized by having a plan relief interspersed with mounds. The knowledge of the levels of trace elements in this environment is important to support sustainable management in areas subject to human intervention in order to reconcile the productive demand and environmental conservation. The objective of this study was to determine the levels and establishing baseline values for trace elements (Zn, Ni, Cu, Cr, Pb, As, Cd, and Se), Fe and Mn in the earth mounds fields soils on the southwest region of the Mato Grosso State. For this soil samples were collected at the depth of 0 to 20 and 20 to 40 cm in "murundus" and "flat" environments, which represent the mounds themselves and the area around it, respectively. The proposition of baseline values was performed according to Conama Resolution 420/2009. The baseline values proposed for these environments were: Zn 7.8; Ni 6.0; Cu 9.2; Cr 21.0; Pb 10.8; As 1.6; Cd <0.03; Se <0.31 and Mn 16.5 mg kg-1 and Fe 4.9 g kg-1. The levels observed reflect the poverty of the source materials of these soils in these elements, as well as the absence of contamination. [ABSTRACT FROM AUTHOR]

The environmental concern permeates different educational levels and researches both nationally and internationally. Nevertheless, it is still possible to observe the presence of experiments in higher education institutions which causes visual impact, for example, the precipitation of lead iodide, a chemical that contains heavy metal. Avoid generation of chemical waste permeates the professional training as part of their dayto- day. This article reports a proposed replacement of an experiment in experimental general chemistry classes in higher education whose product the heavy metal lead (Pb) involving a precipitation reaction to another with the formation of precipitate without the presence of a heavy metal. [ABSTRACT FROM AUTHOR]

Due to the few studies regarding the use of living cells on metal removal, in this research it was aimed to evaluate the removal of copper by Enterococcus faecalis ATCC 51299 and by Salmonella enterica sorovar Enteritidis CCT 4475 in continuous growth. Te results demonstrated significant effect (P<0.05) for the species and copper concentrations factors, depending on the growth, total removal and intracellular copper accumulation. Te different copper concentrations circumstantially limited biomass growth, though the metal concentrations used were not inhibitory, suggesting the development of physiologic adaptation to copper metal at concentrations of 7.72 mg L-1 and 15.20 mg L-1 . Salmonella enterica sorovar Enteritidis CCT 4475 showed a higher percentage of total removal and intracellular copper accumulation when compared to Enterococcus faecalis ATCC 51299. However, both strains were able to remove copper in culture medium. These results suggest that the strains being studied exhibit potential for exploration in copper removal process. [ABSTRACT FROM AUTHOR]

In this study, a pot experiment was developed using a non-metallicolous ecotype of Silene vulgaris Garcke (Moench) exposed to 0, 60 and 120 μM Cd2+ for 13 days. The dose of 60 μM Cd2+ had little effect on the growth of S. vulgaris plants, whereas the highest dose produced a drastic reduction in biomass, and root and shoot elongation. The high internal Cd2+ concentration together with the high bioaccumulation coefficient in roots and the low translocation factor indicated that this ecotype could be a good candidate for the phytostabilisation of Cd2+-contaminated soils. In view of the widespread use of this plant in popular medicine and the cuisine of Mediterranean countries, the results obtained also suggest that caution needs to be taken concerning its origin since it could represent an additional source of Cd2+ in the human diet. [ABSTRACT FROM AUTHOR]

A study during 2011 was carried out in order to evaluate the levels of enzymatic activity and heavy metals bioaccumulated in brain and liver of the species Gambusia punctata, inhabiting San Juan and Filé ecosystems in Santiago de Cuba. For this purpose 3 stations were selected, corresponding to the upper, middle and lower parts of both systems. Specimens biometrically measuring 2.1-3.0 cm in total length were chosen. Acetylcholinesterase enzyme in the brain and glutathione-S-transferase and catalase in the liver were determined, respectively. Copper, zinc, lead and cadmium concentrations were analyzed in both organs, wet processed and quantified by axial view inductively coupled plasma spectroscopy. In San Juan species the enzymatic levels varied between the stations, being higher and statistically different for females (p<0.05), but in that from Filé they were similar between the parts and genders. Regarding metals, concentrations were not detected in brain, neither lead nor cadmium in the liver. Copper and zinc concentrations were higher in the lower part and lower in the upper one, so that there were differences regarding the Filé species. It was concluded that the enzymes varied from an environmentally different station to another and copper and zinc metals, in spite of being essential, pose an ecotoxicological risk in the San Juan species, due to their high bioaccumulative capabilities. [ABSTRACT FROM AUTHOR]

This paper reports the results of the experimental investigation carried out to evaluate the effect of the secondary flow in the separation of lead content in a mixture of water and sediments, using a spiral trough of FLG cross section, with internal radio of 0.025m and an external radio of 0.15m and a pitch of 0.185m. To establish the experimental procedure it was resorted to the method of the dimensional analysis and the randomized factorial design of experiments, being obtained with this design a total of 16 experimental data. The studied answer variables were the concentration of lead in the unload, the partition of water, the removal of sediments and the removal of lead, which depend of parameters non dimensional like Dean's number, relation of radios and the average drag coefficient that it includes the effect of the particles size. With the experimental data the author has obtained empiric equations by means of multiple lineal regression for each one of the responses variables. [ABSTRACT FROM AUTHOR]

Levels of cadmium have been increasing in many agricultural soils mainly due to the anthropogenic actions, such as industrialization and use of inputs in the agriculture. The present research aimed at characterizing the effect of this metal on in vitro growth of two potato cultivars, 'Asterix' and 'Macaca'. Nodal segments of plants previously in vitro established were submitted to cadmium concentration of 0 (control), 100, 200, 300, 400 and 500μM in MS. Number of roots was evaluated at 15 days after inoculation (DAI) of the explants, and root and shoot length, number of nodal segments and leaves, and fresh and dry mass of roots and shoot were evaluated at 22DAI. Cadmium negatively affected the growth of the two potato cultivars, demonstrating that both are sensible to this metal. [ABSTRACT FROM AUTHOR]

We evaluated the effect of a sublethal concentration of cadmium (0.04 μg Cd L-1) on the physiological condition of the juvenile green mussel Perna viridis (22.3 ± 2.33 mm shell height), collected in Guayacán, Sucre State, Venezuela. The mussels were exposed to the sublethal concentration for 7 days, and were then depurated during 52 days simultaneously in the laboratory and in the field in plastic baskets suspended from a long line. In both conditions, the concentration of cadium was measured and different physiological indices were determined: oxygen consumption, ammonia excretion, total protein content in tissues, RNA/DNA ratio, and height and mass of the shell and tissues. No significant differences in the physiological indices were obtained during the depuration process in the laboratory but, in general, all the indices tested increased during depuration in the field. The RNA/DNA index showed great variability, proving to be unsuitable to evaluate the toxic effect of cadmium; however, total protein content, shell and tissue height and mass and, particularly, oxygen consumption and ammonia excretion rate proved to be suitable to evaluate the physiological condition of mussels exposed to subletal concentrations of xenobiotics. [ABSTRACT FROM AUTHOR]

A prata é um elemento usado amplamente pelas suas propriedades antimicrobianas. O uso indiscriminado de antimicrobianos na produção piscícola é cada vez maior o que induz a resistência bacteriana e impactos negativos no meio ambiente. A procura de alternativas para o tratamento de bacterioses é necessária sendo preciso estudas todas as variáveis e efeitos que estes possam gerar no animal e ambiente. No presente ensaio foram estudadas as alterações teciduais induzidas no tambaqui (Colossoma macropomum) pela exposição aguda à prata coloidal. [ABSTRACT FROM AUTHOR]

A prata é um elemento que foi usado durante muitos anos e atualmente é amplamente usado pelas suas propriedades antimicrobianas. Nas últimas décadas, as nanopartículas de prata têm oferecido um campo muito amplo de pesquisa pelas suas extraordinárias atividades biológicas e propriedades físico-químicas como fonte de interesses para novas aplicações além do fato de não induzir resistência bacteriana. No presente estudo foi determinada a concentração letal 50 da prata coloidal em tambaqui (Colossoma macropomum) de forma aguda, 48 horas. [ABSTRACT FROM AUTHOR]